[2/2] mtd: rawnand: meson: add support for Amlogic NAND flash controller

Message ID 20180613161314.14894-3-yixun.lan@amlogic.com
State Changes Requested
Delegated to: Miquel Raynal
Headers show
Series
  • mtd: rawnand: meson: add Amlogic NAND driver support
Related show

Commit Message

Yixun Lan June 13, 2018, 4:13 p.m.
From: Liang Yang <liang.yang@amlogic.com>

Add initial support for the Amlogic NAND flash controller which found
in the Meson-GXBB/GXL/AXG SoCs.

Singed-off-by: Liang Yang <liang.yang@amlogic.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
---
 drivers/mtd/nand/raw/Kconfig      |    8 +
 drivers/mtd/nand/raw/Makefile     |    3 +
 drivers/mtd/nand/raw/meson_nand.c | 1422 +++++++++++++++++++++++++++++
 3 files changed, 1433 insertions(+)
 create mode 100644 drivers/mtd/nand/raw/meson_nand.c

Comments

kbuild test robot June 13, 2018, 9:07 a.m. | #1
Hi Liang,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on mtd/nand/next]
[also build test ERROR on v4.17 next-20180613]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Yixun-Lan/mtd-rawnand-meson-add-Amlogic-NAND-driver-support/20180613-161917
base:   git://git.infradead.org/linux-mtd.git nand/next
config: sparc64-allyesconfig (attached as .config)
compiler: sparc64-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.2.0 make.cross ARCH=sparc64 

All error/warnings (new ones prefixed by >>):

   In file included from drivers/mtd/nand/raw/meson_nand.c:21:0:
>> drivers/clk/meson/clk-regmap.h:22:16: error: field 'hw' has incomplete type
     struct clk_hw hw;
                   ^~
>> drivers/mtd/nand/raw/meson_nand.c:951:2: error: field name not in record or union initializer
     .hw.init = &(struct clk_init_data) {
     ^
   drivers/mtd/nand/raw/meson_nand.c:951:2: note: (near initialization for 'sd_emmc_c_ext_clk0_sel')
>> drivers/mtd/nand/raw/meson_nand.c:952:4: error: 'struct clk_init_data' has no member named 'name'
      .name = "sd_emmc_c_nand_clk_mux",
       ^~~~
>> drivers/mtd/nand/raw/meson_nand.c:952:11: warning: excess elements in struct initializer
      .name = "sd_emmc_c_nand_clk_mux",
              ^~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mtd/nand/raw/meson_nand.c:952:11: note: (near initialization for '(anonymous)')
>> drivers/mtd/nand/raw/meson_nand.c:953:4: error: 'struct clk_init_data' has no member named 'ops'
      .ops = &clk_regmap_mux_ops,
       ^~~
   drivers/mtd/nand/raw/meson_nand.c:953:10: warning: excess elements in struct initializer
      .ops = &clk_regmap_mux_ops,
             ^
   drivers/mtd/nand/raw/meson_nand.c:953:10: note: (near initialization for '(anonymous)')
>> drivers/mtd/nand/raw/meson_nand.c:954:4: error: 'struct clk_init_data' has no member named 'parent_names'
      .parent_names = sd_emmc_ext_clk0_parent_names,
       ^~~~~~~~~~~~
   drivers/mtd/nand/raw/meson_nand.c:954:19: warning: excess elements in struct initializer
      .parent_names = sd_emmc_ext_clk0_parent_names,
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mtd/nand/raw/meson_nand.c:954:19: note: (near initialization for '(anonymous)')
>> drivers/mtd/nand/raw/meson_nand.c:955:4: error: 'struct clk_init_data' has no member named 'num_parents'
      .num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
       ^~~~~~~~~~~
   In file included from include/linux/list.h:9:0,
                    from include/linux/kobject.h:19,
                    from include/linux/device.h:16,
                    from include/linux/platform_device.h:14,
                    from drivers/mtd/nand/raw/meson_nand.c:9:
>> include/linux/kernel.h:71:25: warning: excess elements in struct initializer
    #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
                            ^
>> drivers/mtd/nand/raw/meson_nand.c:955:18: note: in expansion of macro 'ARRAY_SIZE'
      .num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
                     ^~~~~~~~~~
   include/linux/kernel.h:71:25: note: (near initialization for '(anonymous)')
    #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
                            ^
>> drivers/mtd/nand/raw/meson_nand.c:955:18: note: in expansion of macro 'ARRAY_SIZE'
      .num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
                     ^~~~~~~~~~
>> drivers/mtd/nand/raw/meson_nand.c:956:4: error: 'struct clk_init_data' has no member named 'flags'
      .flags = CLK_SET_RATE_PARENT,
       ^~~~~
>> drivers/mtd/nand/raw/meson_nand.c:956:12: error: 'CLK_SET_RATE_PARENT' undeclared here (not in a function); did you mean 'DL_STATE_DORMANT'?
      .flags = CLK_SET_RATE_PARENT,
               ^~~~~~~~~~~~~~~~~~~
               DL_STATE_DORMANT
   drivers/mtd/nand/raw/meson_nand.c:956:12: warning: excess elements in struct initializer
   drivers/mtd/nand/raw/meson_nand.c:956:12: note: (near initialization for '(anonymous)')
>> drivers/mtd/nand/raw/meson_nand.c:951:37: error: invalid use of undefined type 'struct clk_init_data'
     .hw.init = &(struct clk_init_data) {
                                        ^
>> drivers/mtd/nand/raw/meson_nand.c:965:12: error: 'CLK_DIVIDER_ROUND_CLOSEST' undeclared here (not in a function); did you mean 'DIV_ROUND_CLOSEST'?
      .flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
               ^~~~~~~~~~~~~~~~~~~~~~~~~
               DIV_ROUND_CLOSEST
>> drivers/mtd/nand/raw/meson_nand.c:965:40: error: 'CLK_DIVIDER_ONE_BASED' undeclared here (not in a function); did you mean 'CLK_DIVIDER_ROUND_CLOSEST'?
      .flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
                                           ^~~~~~~~~~~~~~~~~~~~~
                                           CLK_DIVIDER_ROUND_CLOSEST
   drivers/mtd/nand/raw/meson_nand.c:967:2: error: field name not in record or union initializer
     .hw.init = &(struct clk_init_data) {
     ^
   drivers/mtd/nand/raw/meson_nand.c:967:2: note: (near initialization for 'sd_emmc_c_ext_clk0_div')
   drivers/mtd/nand/raw/meson_nand.c:968:4: error: 'struct clk_init_data' has no member named 'name'
      .name = "sd_emmc_c_nand_clk_div",
       ^~~~
   drivers/mtd/nand/raw/meson_nand.c:968:11: warning: excess elements in struct initializer
      .name = "sd_emmc_c_nand_clk_div",
              ^~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mtd/nand/raw/meson_nand.c:968:11: note: (near initialization for '(anonymous)')
   drivers/mtd/nand/raw/meson_nand.c:969:4: error: 'struct clk_init_data' has no member named 'ops'
      .ops = &clk_regmap_divider_ops,
       ^~~
   drivers/mtd/nand/raw/meson_nand.c:969:10: warning: excess elements in struct initializer
      .ops = &clk_regmap_divider_ops,
             ^
   drivers/mtd/nand/raw/meson_nand.c:969:10: note: (near initialization for '(anonymous)')
   drivers/mtd/nand/raw/meson_nand.c:970:4: error: 'struct clk_init_data' has no member named 'parent_names'
      .parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
       ^~~~~~~~~~~~
   drivers/mtd/nand/raw/meson_nand.c:970:19: warning: excess elements in struct initializer
      .parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
                      ^
   drivers/mtd/nand/raw/meson_nand.c:970:19: note: (near initialization for '(anonymous)')
   drivers/mtd/nand/raw/meson_nand.c:971:4: error: 'struct clk_init_data' has no member named 'num_parents'
      .num_parents = 1,
       ^~~~~~~~~~~
   drivers/mtd/nand/raw/meson_nand.c:971:18: warning: excess elements in struct initializer
      .num_parents = 1,
                     ^
   drivers/mtd/nand/raw/meson_nand.c:971:18: note: (near initialization for '(anonymous)')
   drivers/mtd/nand/raw/meson_nand.c:972:4: error: 'struct clk_init_data' has no member named 'flags'
      .flags = CLK_SET_RATE_PARENT,
       ^~~~~
   drivers/mtd/nand/raw/meson_nand.c:972:12: warning: excess elements in struct initializer
      .flags = CLK_SET_RATE_PARENT,
               ^~~~~~~~~~~~~~~~~~~
   drivers/mtd/nand/raw/meson_nand.c:972:12: note: (near initialization for '(anonymous)')
   drivers/mtd/nand/raw/meson_nand.c: In function 'meson_nfc_clk_init':
>> drivers/mtd/nand/raw/meson_nand.c:1007:38: error: implicit declaration of function '__clk_get_name'; did you mean 'clk_get_rate'? [-Werror=implicit-function-declaration]
      sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
                                         ^~~~~~~~~~~~~~
                                         clk_get_rate
>> drivers/mtd/nand/raw/meson_nand.c:1007:36: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
      sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
                                       ^
>> drivers/mtd/nand/raw/meson_nand.c:1011:8: error: implicit declaration of function 'devm_clk_register'; did you mean 'device_register'? [-Werror=implicit-function-declaration]
     clk = devm_clk_register(nfc->dev, &mux->hw);
           ^~~~~~~~~~~~~~~~~
           device_register
   cc1: some warnings being treated as errors
--
   In file included from drivers/mtd//nand/raw/meson_nand.c:21:0:
>> drivers/clk/meson/clk-regmap.h:22:16: error: field 'hw' has incomplete type
     struct clk_hw hw;
                   ^~
   drivers/mtd//nand/raw/meson_nand.c:951:2: error: field name not in record or union initializer
     .hw.init = &(struct clk_init_data) {
     ^
   drivers/mtd//nand/raw/meson_nand.c:951:2: note: (near initialization for 'sd_emmc_c_ext_clk0_sel')
   drivers/mtd//nand/raw/meson_nand.c:952:4: error: 'struct clk_init_data' has no member named 'name'
      .name = "sd_emmc_c_nand_clk_mux",
       ^~~~
   drivers/mtd//nand/raw/meson_nand.c:952:11: warning: excess elements in struct initializer
      .name = "sd_emmc_c_nand_clk_mux",
              ^~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mtd//nand/raw/meson_nand.c:952:11: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c:953:4: error: 'struct clk_init_data' has no member named 'ops'
      .ops = &clk_regmap_mux_ops,
       ^~~
   drivers/mtd//nand/raw/meson_nand.c:953:10: warning: excess elements in struct initializer
      .ops = &clk_regmap_mux_ops,
             ^
   drivers/mtd//nand/raw/meson_nand.c:953:10: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c:954:4: error: 'struct clk_init_data' has no member named 'parent_names'
      .parent_names = sd_emmc_ext_clk0_parent_names,
       ^~~~~~~~~~~~
   drivers/mtd//nand/raw/meson_nand.c:954:19: warning: excess elements in struct initializer
      .parent_names = sd_emmc_ext_clk0_parent_names,
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mtd//nand/raw/meson_nand.c:954:19: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c:955:4: error: 'struct clk_init_data' has no member named 'num_parents'
      .num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
       ^~~~~~~~~~~
   In file included from include/linux/list.h:9:0,
                    from include/linux/kobject.h:19,
                    from include/linux/device.h:16,
                    from include/linux/platform_device.h:14,
                    from drivers/mtd//nand/raw/meson_nand.c:9:
>> include/linux/kernel.h:71:25: warning: excess elements in struct initializer
    #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
                            ^
   drivers/mtd//nand/raw/meson_nand.c:955:18: note: in expansion of macro 'ARRAY_SIZE'
      .num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
                     ^~~~~~~~~~
   include/linux/kernel.h:71:25: note: (near initialization for '(anonymous)')
    #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
                            ^
   drivers/mtd//nand/raw/meson_nand.c:955:18: note: in expansion of macro 'ARRAY_SIZE'
      .num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
                     ^~~~~~~~~~
   drivers/mtd//nand/raw/meson_nand.c:956:4: error: 'struct clk_init_data' has no member named 'flags'
      .flags = CLK_SET_RATE_PARENT,
       ^~~~~
   drivers/mtd//nand/raw/meson_nand.c:956:12: error: 'CLK_SET_RATE_PARENT' undeclared here (not in a function); did you mean 'DL_STATE_DORMANT'?
      .flags = CLK_SET_RATE_PARENT,
               ^~~~~~~~~~~~~~~~~~~
               DL_STATE_DORMANT
   drivers/mtd//nand/raw/meson_nand.c:956:12: warning: excess elements in struct initializer
   drivers/mtd//nand/raw/meson_nand.c:956:12: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c:951:37: error: invalid use of undefined type 'struct clk_init_data'
     .hw.init = &(struct clk_init_data) {
                                        ^
   drivers/mtd//nand/raw/meson_nand.c:965:12: error: 'CLK_DIVIDER_ROUND_CLOSEST' undeclared here (not in a function); did you mean 'DIV_ROUND_CLOSEST'?
      .flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
               ^~~~~~~~~~~~~~~~~~~~~~~~~
               DIV_ROUND_CLOSEST
   drivers/mtd//nand/raw/meson_nand.c:965:40: error: 'CLK_DIVIDER_ONE_BASED' undeclared here (not in a function); did you mean 'CLK_DIVIDER_ROUND_CLOSEST'?
      .flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
                                           ^~~~~~~~~~~~~~~~~~~~~
                                           CLK_DIVIDER_ROUND_CLOSEST
   drivers/mtd//nand/raw/meson_nand.c:967:2: error: field name not in record or union initializer
     .hw.init = &(struct clk_init_data) {
     ^
   drivers/mtd//nand/raw/meson_nand.c:967:2: note: (near initialization for 'sd_emmc_c_ext_clk0_div')
   drivers/mtd//nand/raw/meson_nand.c:968:4: error: 'struct clk_init_data' has no member named 'name'
      .name = "sd_emmc_c_nand_clk_div",
       ^~~~
   drivers/mtd//nand/raw/meson_nand.c:968:11: warning: excess elements in struct initializer
      .name = "sd_emmc_c_nand_clk_div",
              ^~~~~~~~~~~~~~~~~~~~~~~~
   drivers/mtd//nand/raw/meson_nand.c:968:11: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c:969:4: error: 'struct clk_init_data' has no member named 'ops'
      .ops = &clk_regmap_divider_ops,
       ^~~
   drivers/mtd//nand/raw/meson_nand.c:969:10: warning: excess elements in struct initializer
      .ops = &clk_regmap_divider_ops,
             ^
   drivers/mtd//nand/raw/meson_nand.c:969:10: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c:970:4: error: 'struct clk_init_data' has no member named 'parent_names'
      .parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
       ^~~~~~~~~~~~
   drivers/mtd//nand/raw/meson_nand.c:970:19: warning: excess elements in struct initializer
      .parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
                      ^
   drivers/mtd//nand/raw/meson_nand.c:970:19: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c:971:4: error: 'struct clk_init_data' has no member named 'num_parents'
      .num_parents = 1,
       ^~~~~~~~~~~
   drivers/mtd//nand/raw/meson_nand.c:971:18: warning: excess elements in struct initializer
      .num_parents = 1,
                     ^
   drivers/mtd//nand/raw/meson_nand.c:971:18: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c:972:4: error: 'struct clk_init_data' has no member named 'flags'
      .flags = CLK_SET_RATE_PARENT,
       ^~~~~
   drivers/mtd//nand/raw/meson_nand.c:972:12: warning: excess elements in struct initializer
      .flags = CLK_SET_RATE_PARENT,
               ^~~~~~~~~~~~~~~~~~~
   drivers/mtd//nand/raw/meson_nand.c:972:12: note: (near initialization for '(anonymous)')
   drivers/mtd//nand/raw/meson_nand.c: In function 'meson_nfc_clk_init':
   drivers/mtd//nand/raw/meson_nand.c:1007:38: error: implicit declaration of function '__clk_get_name'; did you mean 'clk_get_rate'? [-Werror=implicit-function-declaration]
      sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
                                         ^~~~~~~~~~~~~~
                                         clk_get_rate
   drivers/mtd//nand/raw/meson_nand.c:1007:36: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
      sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
                                       ^
   drivers/mtd//nand/raw/meson_nand.c:1011:8: error: implicit declaration of function 'devm_clk_register'; did you mean 'device_register'? [-Werror=implicit-function-declaration]
     clk = devm_clk_register(nfc->dev, &mux->hw);
           ^~~~~~~~~~~~~~~~~
           device_register
   cc1: some warnings being treated as errors

vim +/hw +22 drivers/clk/meson/clk-regmap.h

ea11dda9 Jerome Brunet 2018-02-12  10  
ea11dda9 Jerome Brunet 2018-02-12  11  /**
ea11dda9 Jerome Brunet 2018-02-12  12   * struct clk_regmap - regmap backed clock
ea11dda9 Jerome Brunet 2018-02-12  13   *
ea11dda9 Jerome Brunet 2018-02-12  14   * @hw:		handle between common and hardware-specific interfaces
ea11dda9 Jerome Brunet 2018-02-12  15   * @map:	pointer to the regmap structure controlling the clock
ea11dda9 Jerome Brunet 2018-02-12  16   * @data:	data specific to the clock type
ea11dda9 Jerome Brunet 2018-02-12  17   *
ea11dda9 Jerome Brunet 2018-02-12  18   * Clock which is controlled by regmap backed registers. The actual type of
ea11dda9 Jerome Brunet 2018-02-12  19   * of the clock is controlled by the clock_ops and data.
ea11dda9 Jerome Brunet 2018-02-12  20   */
ea11dda9 Jerome Brunet 2018-02-12  21  struct clk_regmap {
ea11dda9 Jerome Brunet 2018-02-12 @22  	struct clk_hw	hw;
ea11dda9 Jerome Brunet 2018-02-12  23  	struct regmap	*map;
ea11dda9 Jerome Brunet 2018-02-12  24  	void		*data;
ea11dda9 Jerome Brunet 2018-02-12  25  };
ea11dda9 Jerome Brunet 2018-02-12  26  

:::::: The code at line 22 was first introduced by commit
:::::: ea11dda9e091aba0fe6497108477699286a2d036 clk: meson: add regmap clocks

:::::: TO: Jerome Brunet <jbrunet@baylibre.com>
:::::: CC: Neil Armstrong <narmstrong@baylibre.com>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
kbuild test robot June 13, 2018, 9:33 a.m. | #2
Hi Liang,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on mtd/nand/next]
[also build test ERROR on v4.17 next-20180613]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Yixun-Lan/mtd-rawnand-meson-add-Amlogic-NAND-driver-support/20180613-161917
base:   git://git.infradead.org/linux-mtd.git nand/next
config: i386-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

>> drivers/mtd/nand/raw/meson_nand.c:21:10: fatal error: clk-regmap.h: No such file or directory
    #include "clk-regmap.h"
             ^~~~~~~~~~~~~~
   compilation terminated.

vim +21 drivers/mtd/nand/raw/meson_nand.c

  > 21	#include "clk-regmap.h"
    22	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
Boris Brezillon June 24, 2018, 7:38 p.m. | #3
Hi Yixun,

On Wed, 13 Jun 2018 16:13:14 +0000
Yixun Lan <yixun.lan@amlogic.com> wrote:

> From: Liang Yang <liang.yang@amlogic.com>
> 
> Add initial support for the Amlogic NAND flash controller which found
> in the Meson-GXBB/GXL/AXG SoCs.
> 
> Singed-off-by: Liang Yang <liang.yang@amlogic.com>
> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
> ---
>  drivers/mtd/nand/raw/Kconfig      |    8 +
>  drivers/mtd/nand/raw/Makefile     |    3 +
>  drivers/mtd/nand/raw/meson_nand.c | 1422 +++++++++++++++++++++++++++++
>  3 files changed, 1433 insertions(+)
>  create mode 100644 drivers/mtd/nand/raw/meson_nand.c

Can you run checkpatch.pl --strict and fix the coding style issues?

> 
> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> index 19a2b283fbbe..b3c17a3ca8f4 100644
> --- a/drivers/mtd/nand/raw/Kconfig
> +++ b/drivers/mtd/nand/raw/Kconfig
> @@ -534,4 +534,12 @@ config MTD_NAND_MTK
>  	  Enables support for NAND controller on MTK SoCs.
>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
>  
> +config MTD_NAND_MESON
> +	tristate "Support for NAND flash controller on Amlogic's Meson SoCs"
> +	depends on ARCH_MESON || COMPILE_TEST
> +	select COMMON_CLK_REGMAP_MESON
> +	select MFD_SYSCON
> +	help
> +	  Enables support for NAND controller on Amlogic's Meson SoCs.
> +
>  endif # MTD_NAND
> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
> index 165b7ef9e9a1..cdf6162f38c3 100644
> --- a/drivers/mtd/nand/raw/Makefile
> +++ b/drivers/mtd/nand/raw/Makefile
> @@ -1,5 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0
>  
> +ccflags-$(CONFIG_MTD_NAND_MESON) += -I$(srctree)/drivers/clk/meson

Please don't do that. If you need to expose common regs, put them
in include/linux/soc/meson/. I'm also not sure why you need to access
the clk regs directly. Why can't you expose the MMC/NAND clk as a clk
provider whose driver would be placed in drivers/clk and which would use
the mmc syscon. This way the same clk driver could be used for both
MMC and NAND clk indifferently, and the NAND driver would be much
simpler.

> +
>  obj-$(CONFIG_MTD_NAND)			+= nand.o
>  obj-$(CONFIG_MTD_NAND_ECC)		+= nand_ecc.o
>  obj-$(CONFIG_MTD_NAND_BCH)		+= nand_bch.o
> @@ -56,6 +58,7 @@ obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
>  obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
>  obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
>  obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
> +obj-$(CONFIG_MTD_NAND_MESON)		+= meson_nand.o
>  
>  nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
>  nand-objs += nand_amd.o
> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> new file mode 100644
> index 000000000000..28abc3684772
> --- /dev/null
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -0,0 +1,1422 @@
> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
> +/*
> + * Amlogic Meson Nand Flash Controller Driver
> + *
> + * Copyright (c) 2018 Amlogic, inc.
> + * Author: Liang Yang <liang.yang@amlogic.com>
> + */
> +
> +#include <linux/platform_device.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/clk.h>
> +#include <linux/mtd/rawnand.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +#include <linux/module.h>
> +#include <linux/iopoll.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include "clk-regmap.h"
> +
> +#define NFC_REG_CMD		0x00
> +#define NFC_REG_CFG		0x04
> +#define NFC_REG_DADR		0x08
> +#define NFC_REG_IADR		0x0c
> +#define NFC_REG_BUF		0x10
> +#define NFC_REG_INFO		0x14
> +#define NFC_REG_DC		0x18
> +#define NFC_REG_ADR		0x1c
> +#define NFC_REG_DL		0x20
> +#define NFC_REG_DH		0x24
> +#define NFC_REG_CADR		0x28
> +#define NFC_REG_SADR		0x2c
> +#define NFC_REG_PINS		0x30
> +#define NFC_REG_VER		0x38
> +

Can you put the reg offsets next to their field definitions?

> +
> +#define NFC_CMD_DRD		(0x8 << 14)
> +#define NFC_CMD_IDLE		(0xc << 14)
> +#define NFC_CMD_DWR		(0x4 << 14)
> +#define NFC_CMD_CLE		(0x5 << 14)
> +#define NFC_CMD_ALE		(0x6 << 14)
> +#define NFC_CMD_ADL		((0 << 16) | (3 << 20))
> +#define NFC_CMD_ADH		((1 << 16) | (3 << 20))
> +#define NFC_CMD_AIL		((2 << 16) | (3 << 20))
> +#define NFC_CMD_AIH		((3 << 16) | (3 << 20))
> +#define NFC_CMD_SEED		((8 << 16) | (3 << 20))
> +#define NFC_CMD_M2N		((0 << 17) | (2 << 20))
> +#define NFC_CMD_N2M		((1 << 17) | (2 << 20))
> +#define NFC_CMD_RB		(1 << 20)
> +#define NFC_CMD_IO6		((0xb << 10) | (1 << 18))
> +
> +#define NFC_RB_USED		(1 << 23)
> +#define NFC_LARGE_PAGE		(1 << 22)
> +#define NFC_RW_OPS		(2 << 20)
> +
> +#define NAND_TWB_TIME_CYCLE	10
> +
> +#define CMDRWGEN(cmd_dir, ran, bch, short_mode, page_size, pages)	\
> +	(								\
> +		(cmd_dir)			|			\
> +		((ran) << 19)			|			\
> +		((bch) << 14)			| 			\
> +		((short_mode) << 13)		|			\
> +		(((page_size) & 0x7f) << 6)	|			\
> +		((pages) & 0x3f)					\
> +	)
> +
> +#define GENCMDDADDRL(adl, addr)		((adl) | ((addr) & 0xffff))
> +#define GENCMDDADDRH(adh, addr)		((adh) | (((addr) >> 16) & 0xffff))
> +#define GENCMDIADDRL(ail, addr)		((ail) | ((addr) & 0xffff))
> +#define GENCMDIADDRH(aih, addr)		((aih) | (((addr) >> 16) & 0xffff))
> +
> +#define RB_STA(x)		(1 << (26 + x))
> +
> +#define ECC_CHECK_RETURN_FF	(-1)
> +
> +#define NAND_CE0		(0xe << 10)
> +#define NAND_CE1		(0xd << 10)
> +
> +#define DMA_BUSY_TIMEOUT	0x100000
> +
> +#define MAX_CE_NUM		2
> +#define RAN_ENABLE		1
> +
> +#define SD_EMMC_CLOCK 		0x00
> +#define CLK_ALWAYS_ON		BIT(28)
> +#define CLK_SELECT_NAND		BIT(31)
> +#define CLK_DIV_MASK		GENMASK(5, 0)
> +#define CLK_SRC_MASK		GENMASK(7, 6)
> +
> +#define NFC_CLK_CYCLE		6
> +
> +/* nand flash controller delay 3 ns */
> +#define NFC_DEFAULT_DELAY 3000
> +
> +#define MAX_ECC_INDEX	10
> +
> +#define MUX_CLK_NUM_PARENTS 2
> +
> +struct meson_nfc_info_format {
> +	u16 info_bytes;
> +	u8 zero_cnt; /* bit0~5 is valid */
> +	struct ecc_sta {
> +		u8 eccerr_cnt : 6;
> +		u8 notused : 1;
> +		u8 completed : 1;
> +	} ecc;
> +	u32 reserved;
> +};
> +
> +#define	PER_INFO_BYTE	(sizeof(struct meson_nfc_info_format))
> +
> +struct meson_nfc_nand_chip {
> +	struct list_head node;
> +	struct nand_chip nand;
> +	/*
> +	 * Then NAND controller support two oob modes:
> +	 *  a) 2 user bytes with each ecc page;
> +	 *  b) 16 user bytes with 1st ecc page and zero user byte
> +	 *      with the other ecc pages.
> +	 * when using as mtd mode, the driver prefer to use 2 user bytes mode.

Why not using this mode unconditionally? What's the point of
maintaining 2 different page layout if only one is used?

> +	 */
> +	int user_mode;
> +	int rand_mode; /* 0: disable scramble, 1: enable scramble */
> +	int bch_mode;
> +	int cs;
> +
> +	u8 *data_buf;
> +	u8 *info_buf;
> +};
> +
> +/*
> + * While booting from NAND, a page0 data is needed to tell ROM boot code
> + * to read SPL image, and the ROM boot code need to know which ecc mode
> + * is selected and whether scramble is enabled or not, and so on.
> + *
> + * So when updating SPL image, the driver need to store these informations
> + * into the page0, and SPL image will be loadded into next page - the page1.

Clearly not the kind of information that belongs in the NAND controller
driver. We had the same problem on sunxi platforms where the first few
blocks are written with a different ECC/scrambler setup (the
ROM code only supports a pre-defined set of ECC/scrambler configs that
it tries until it finds one that works).

What we did to solve that is write the SPL partition in raw mode (ECC
and scrambler disabled) with an image that already contains the ECC
bytes has the data appropriately scrambled (for the record, we use the
sunxi-spl-image-builder [1] tool to generate this raw image).

> + */
> +struct meson_nand_setup {
> +	u32 d32;
> +	u16 id;
> +	u16 max;
> +};
> +
> +struct meson_nand_page0 {
> +	struct meson_nand_setup nand_setup;
> +	unsigned char page_list[16];
> +	unsigned short reserved[32];
> +};
> +
> +struct meson_nand_ecc {
> +	int bch;
> +	int strength;
> +	int parity;
> +};
> +
> +struct meson_nfc_data {
> +	struct meson_nand_ecc *ecc;
> +	int ecc_num;
> +	int bch_mode;
> +	int short_bch;
> +};
> +
> +struct meson_nfc_param {
> +	int chip_select;
> +	int rb_select;
> +
> +	int page_size;
> +	int oob_size;
> +	int ecc_size;
> +	int ecc_bytes;
> +
> +	int rand_mode;
> +	int oob_mode;
> +	int bch_mode;
> +	int ecc_step;
> +
> +	int ecc_max;
> +};

Looks like most of these information are tied to the NAND chip and not
the NAND controller. They should probably be moved to
meson_nfc_nand_chip.

> +
> +struct meson_nfc {
> +	struct nand_hw_control controller;
> +	struct clk *core_clk;
> +	struct clk *device_clk;
> +
> +	struct device *dev;
> +	void __iomem *reg_base;
> +	struct regmap *reg_clk;
> +
> +	struct completion completion;
> +	struct list_head chips;
> +	struct meson_nfc_data *data;
> +	struct meson_nfc_param param;
> +	struct meson_nand_page0 *page0;
> +
> +	u8 *data_buf;
> +	u8 *info_buf;
> +};
> +
> +enum {
> +	NFC_ECC_NONE	= 0,
> +	NFC_ECC_BCH8,		/* bch8 with ecc page size of 512B */
> +	NFC_ECC_BCH8_1K,	/* bch8 with ecc page size of 1024B */
> +	NFC_ECC_BCH24_1K,
> +	NFC_ECC_BCH30_1K,
> +	NFC_ECC_BCH40_1K,
> +	NFC_ECC_BCH50_1K,
> +	NFC_ECC_BCH60_1K,
> +
> +	/*
> +	 * Short mode is special only for page 0 when inplement booting
> +	 * from nand, which means a small size(384 bit / 8 = 48 Byte) of
> +	 * ecc page is used with a fixed ecc mode. rom code will use short mode
> +	 * to read page0 for getting nand parameters such as ecc, scramber, etc.
> +	 *
> +	 * Example, in GXL SoC, the first page adopt the short mode with
> +	 * 60bit ecc, while in AXG SoC, it adopt short mode with 8bit ecc.
> +	 */
> +	NFC_ECC_BCH_SHORT,

Let's see if we can avoid supporting this mode. I'm pretty sure you
have all the information you need to generate ECC bytes and scramble
data in SW. Then, all you'll need from the NAND controller driver is a
way to write thing in raw mode, which I'll ask you to support
anyway ;-).

> +};
> +
> +enum {
> +	NFC_USER2_OOB_BYTES		= 2,
> +	NFC_USER16_OOB_BYTES		= 16,
> +};
> +
> +#define MESON_ECC_DATA(b, s, p)				\
> +	{ .bch = (b),	.strength = (s),	.parity = (p) }
> +
> +struct meson_nand_ecc meson_gxl_ecc[] = {
> +	MESON_ECC_DATA(NFC_ECC_NONE, 0, 0),
> +	MESON_ECC_DATA(NFC_ECC_BCH8, 8, 14),
> +	MESON_ECC_DATA(NFC_ECC_BCH8_1K, 8, 14),
> +	MESON_ECC_DATA(NFC_ECC_BCH24_1K, 24, 42),
> +	MESON_ECC_DATA(NFC_ECC_BCH30_1K, 30, 54),
> +	MESON_ECC_DATA(NFC_ECC_BCH40_1K, 40, 70),
> +	MESON_ECC_DATA(NFC_ECC_BCH50_1K, 50, 88),
> +	MESON_ECC_DATA(NFC_ECC_BCH60_1K, 60, 106),
> +	MESON_ECC_DATA(NFC_ECC_BCH_SHORT, 0xff, 0xff),
> +};
> +
> +struct meson_nand_ecc meson_axg_ecc[] = {
> +	MESON_ECC_DATA(NFC_ECC_NONE, 0, 0),
> +	MESON_ECC_DATA(NFC_ECC_BCH8, 8, 14),
> +	MESON_ECC_DATA(NFC_ECC_BCH8_1K, 8, 14),
> +	MESON_ECC_DATA(NFC_ECC_BCH_SHORT, 0xff, 0xff),
> +};
> +
> +static inline struct meson_nfc_nand_chip *to_meson_nand(struct nand_chip *nand)
> +{
> +	return container_of(nand, struct meson_nfc_nand_chip, nand);
> +}
> +
> +static int meson_nfc_page0_gen(struct meson_nfc *nfc)
> +{
> +	u32 cmd;
> +
> +	nfc->page0 = devm_kzalloc(nfc->dev,
> +		sizeof(struct meson_nand_page0), GFP_KERNEL);
> +	if(!nfc->page0)
> +		return -ENOMEM;
> +
> +	cmd = CMDRWGEN(NFC_CMD_N2M, nfc->param.rand_mode,
> +		nfc->param.bch_mode, 0,
> +		nfc->param.ecc_size >> 3,
> +		nfc->param.ecc_step);
> +	cmd |= NFC_RB_USED | NFC_LARGE_PAGE | NFC_RW_OPS;
> +	nfc->page0->nand_setup.d32 = cmd;
> +
> +	return 0;
> +}
> +
> +static void meson_nfc_select_chip(struct mtd_info *mtd, int chip)
> +{
> +	struct nand_chip *nand = mtd_to_nand(mtd);
> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
> +
> +	if (chip != meson_chip->cs)

I know it's not clear at all, but chip is not encoding the NAND
controller CS id, but the NAND chip CS id, which can be != 0 for
multi-die chips.

To extract the NAND controller CS id, you'll have to parse the NAND
chip node reg prop, and store the information somewhere in
meson_nfc_nand_chip. Go check the sunxi if you want an example.

> +		return;
> +
> +	nfc->param.chip_select = chip ? NAND_CE1 : NAND_CE0;
> +	nfc->param.rb_select = chip ? NAND_CE1 : NAND_CE0;
> +	nfc->param.oob_mode =
> +		(meson_chip->user_mode == NFC_USER2_OOB_BYTES) ? 0 : 1;
> +	nfc->param.rand_mode = meson_chip->rand_mode;
> +	nfc->param.bch_mode = meson_chip->bch_mode;
> +
> +	nfc->param.ecc_step = mtd->writesize / nand->ecc.size;
> +	nfc->param.ecc_size = nand->ecc.size;
> +	nfc->param.ecc_bytes =  nand->ecc.bytes;
> +	nfc->param.page_size = mtd->writesize;
> +	nfc->param.oob_size =  mtd->oobsize;
> +	nfc->param.ecc_max = nand->ecc.strength;
> +
> +	nfc->data_buf = meson_chip->data_buf;
> +	nfc->info_buf = meson_chip->info_buf;
> +}
> +
> +static inline void meson_nfc_cmd_idle(struct meson_nfc *nfc, u32 time)
> +{
> +	writel(nfc->param.chip_select | NFC_CMD_IDLE | (time & 0x3ff),
> +			nfc->reg_base + NFC_REG_CMD);
> +}
> +
> +static void meson_nfc_cmd_ctrl(struct mtd_info *mtd,
> +					int cmd, unsigned int ctrl)

->cmd_ctrl() has recently been deprecated in favor of ->exec_op(). You
can have a look at the marvell, v610 or fsmc drivers if you want to
have an idea of how ->exec_op() should be implemented. Miquel and I are
also here to help if you have any questions.

> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
> +
> +	if (cmd == NAND_CMD_NONE)
> +		return;
> +
> +	cmd = nfc->param.chip_select | (cmd & 0xff);
> +	cmd |= (ctrl & NAND_CLE) ? NFC_CMD_CLE : NFC_CMD_ALE;
> +
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +}
> +
> +static inline void meson_nfc_cmd_seed(struct meson_nfc *nfc, u32 seed)
> +{
> +	writel(NFC_CMD_SEED | (0xc2 + (seed & 0x7fff)),
> +			nfc->reg_base + NFC_REG_CMD);
> +}
> +
> +static void meson_nfc_cmd_m2n(struct meson_nfc *nfc, int raw)

n2m -> nand2mem ?

> +{
> +	u32 cmd, pagesize, pages, shortm = 0;
> +	int bch = nfc->param.bch_mode;
> +	int len = nfc->param.page_size;
> +
> +	pagesize = nfc->param.ecc_size;
> +
> +	if (unlikely(raw)) {

I think you'll have plenty of things to optimize before this branch
prediction becomes the bottleneck ;-). Please don't use
unlikely()/likely() statements unless you have numbers showing a
noticeable improvement.

> +		bch = NAND_ECC_NONE;
> +		len = nfc->param.page_size + nfc->param.oob_size;
> +		cmd = NFC_CMD_M2N |
> +			(len & 0x3fff) | (nfc->param.rand_mode << 19);
> +		writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +		return;
> +	}
> +
> +	if (unlikely(bch == NFC_ECC_BCH_SHORT)) {
> +		bch = nfc->data->short_bch;
> +		pagesize = 384 >> 3;
> +		pages = len / nfc->param.ecc_size;
> +		memcpy(nfc->data_buf,
> +			nfc->page0, sizeof(struct meson_nand_page0));
> +		shortm = 1;
> +	} else
> +		pages = len / nfc->param.ecc_size;
> +
> +	cmd = CMDRWGEN(NFC_CMD_M2N,
> +		nfc->param.rand_mode, bch, shortm, pagesize, pages);
> +
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +}
> +
> +static void meson_nfc_cmd_n2m(struct meson_nfc *nfc, int raw)
> +{
> +	u32 cmd, pagesize, pages, shortm = 0;
> +	int bch = nfc->param.bch_mode;
> +	int len = nfc->param.page_size;
> +
> +	pagesize = nfc->param.ecc_size;
> +
> +	if (unlikely(raw)) {
> +		bch = NAND_ECC_NONE;
> +		len = nfc->param.page_size + nfc->param.oob_size;
> +		cmd = (len & 0x3fff) | (nfc->param.rand_mode << 19) |
> +			NFC_CMD_N2M;
> +		writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +		return;
> +	}
> +
> +	if (unlikely(bch == NFC_ECC_BCH_SHORT)) {
> +		bch = nfc->data->short_bch;
> +		pagesize = 384 >> 3;
> +		pages = len / nfc->param.ecc_size;
> +		shortm = 1;
> +	} else
> +		pages = len / nfc->param.ecc_size;
> +
> +	cmd = CMDRWGEN(NFC_CMD_N2M,
> +		nfc->param.rand_mode, bch, shortm, pagesize, pages);
> +
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +}

Looks like there's a lot in common in meson_nfc_cmd_m2n() and
meson_nfc_cmd_n2m(). Wouldn't it be better to have a single function and
pass the direction.

> +
> +static int meson_nfc_wait_cmd_finish(struct meson_nfc *nfc,
> +					unsigned int timeout_ms)
> +{
> +	u32 cmd_size = 0;
> +	int ret;
> +
> +	/* wait cmd fifo is empty */
> +	ret = readl_poll_timeout(nfc->reg_base + NFC_REG_CMD,
> +				cmd_size,
> +				!((cmd_size >> 22) & 0x1f),
> +				10, timeout_ms * 1000);
> +	if (ret)
> +		dev_err(nfc->dev, "wait for empty cmd FIFO time out\n");
> +
> +	return ret;
> +}
> +
> +static int meson_nfc_wait_dma_finish(struct meson_nfc *nfc)
> +{
> +	meson_nfc_cmd_idle(nfc, 0);
> +	meson_nfc_cmd_idle(nfc, 0);

Two calls to cmd_idle(), is this expected or a copy&paste error? If
that's expected it definitely deserves a comment explaining why?

> +
> +	return meson_nfc_wait_cmd_finish(nfc, DMA_BUSY_TIMEOUT);
> +}
> +
> +static inline struct meson_nfc_info_format *nfc_info_ptr(struct meson_nfc *nfc,
> +	int index)
> +{
> +	return (struct meson_nfc_info_format *) &nfc->info_buf[index * 8];
> +}
> +
> +static u8 *meson_nfc_oob_ptr(struct meson_nfc *nfc, int i)
> +{
> +	int x, len;
> +	int ecc_bytes = nfc->param.ecc_bytes, temp = nfc->param.ecc_size;
> +
> +	x = i ? 16 : 0;
> +	len = (nfc->param.oob_mode) ? (temp * (i + 1) + ecc_bytes * i + x) :
> +				(temp * (i + 1) + (ecc_bytes + 2) * i);
> +
> +	return nfc->data_buf + len;
> +}
> +
> +static u8 *meson_nfc_data_ptr(struct meson_nfc *nfc, int i)
> +{
> +	int len, x;
> +	int temp = nfc->param.ecc_size + nfc->param.ecc_bytes;
> +
> +	x = i ? 16 : 0;
> +	len = nfc->param.oob_mode ? (temp * i + x) : (temp + 2) * i;
> +
> +	return nfc->data_buf + len;
> +}
> +
> +static void meson_nfc_prase_data_oob(struct meson_nfc *nfc, u8 *buf, u8 *oob)
> +{
> +	int i, oob_len = 0;
> +	u8 *dsrc, *osrc;
> +
> +	for (i = 0; i < nfc->param.ecc_step; i++) {
> +		if (buf) {
> +			dsrc = meson_nfc_data_ptr(nfc, i);
> +			memcpy(buf, dsrc, nfc->param.ecc_size);
> +			buf += nfc->param.ecc_size;
> +		}
> +
> +		if (nfc->param.oob_mode)
> +			oob_len = (i) ? nfc->param.ecc_bytes :
> +						nfc->param.ecc_bytes + 16;
> +		else
> +			oob_len = nfc->param.ecc_bytes + 2;
> +
> +		osrc = meson_nfc_oob_ptr(nfc, i);
> +		memcpy(oob, osrc, oob_len);
> +		oob += oob_len;
> +	}
> +}
> +
> +static void meson_nfc_format_data_oob(struct meson_nfc *nfc,
> +						const u8 *buf, u8 *oob)
> +{
> +	int i, oob_len = 0;
> +	u8 *dsrc, *osrc;
> +
> +	for (i = 0; i < nfc->param.ecc_step; i++) {
> +		if (buf) {
> +			dsrc = meson_nfc_data_ptr(nfc, i);
> +			memcpy(dsrc, buf, nfc->param.ecc_size);
> +			buf += nfc->param.ecc_size;
> +		}
> +
> +		if (nfc->param.oob_mode)
> +			oob_len = i ? nfc->param.ecc_bytes :
> +						nfc->param.ecc_bytes + 16;
> +		else
> +			oob_len = nfc->param.ecc_bytes + 2;
> +
> +		osrc = meson_nfc_oob_ptr(nfc, i);
> +		memcpy(osrc, oob, oob_len);
> +		oob += oob_len;
> +	}
> +}
> +
> +static int meson_nfc_queue_rb(struct meson_nfc *nfc)
> +{
> +	u32 cmd, cfg;
> +	int ret = 0;
> +
> +	init_completion(&nfc->completion);
> +
> +	cfg = readl(nfc->reg_base + NFC_REG_CFG);
> +	cfg |= (1 << 21);
> +	writel(cfg, nfc->reg_base + NFC_REG_CFG);
> +
> +	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
> +	cmd = nfc->param.chip_select | NFC_CMD_CLE | (NAND_CMD_STATUS & 0xff);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
> +
> +	cmd = NFC_CMD_RB | NFC_CMD_IO6 | (1 << 16) | (0x18 & 0x1f);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +	meson_nfc_cmd_idle(nfc, 2);
> +
> +	ret = wait_for_completion_timeout(&nfc->completion,
> +					msecs_to_jiffies(1000));
> +	if (ret == 0) {
> +		dev_err(nfc->dev, "wait nand irq timeout\n");
> +		ret = -1;
> +	}
> +
> +	return ret;
> +}
> +
> +static void meson_nfc_set_user_byte(struct mtd_info *mtd,
> +					struct nand_chip *chip, u8 *oob_buf)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	struct meson_nfc_info_format *info;
> +	int i, count;
> +
> +	if (nfc->param.oob_mode) {
> +		memcpy(nfc->info_buf, oob_buf, 16);
> +		return;
> +	}
> +
> +	for (i = 0, count = 0; i < chip->ecc.steps; i++, count += 2) {
> +		info = nfc_info_ptr(nfc, i);
> +		info->info_bytes =
> +			oob_buf[count] | (oob_buf[count + 1] << 8);
> +	}
> +}
> +
> +static void meson_nfc_get_user_byte(struct mtd_info *mtd,
> +					struct nand_chip *chip, u8 *oob_buf)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	struct meson_nfc_info_format *info;
> +	int i, count;
> +
> +	if (nfc->param.oob_mode) {
> +		memcpy(oob_buf,  nfc->info_buf, 16);
> +		return;
> +	}
> +
> +	for (i = 0, count = 0; i < chip->ecc.steps; i++, count += 2) {
> +		info = nfc_info_ptr(nfc, i);
> +		oob_buf[count] = info->info_bytes & 0xff;
> +		oob_buf[count + 1] = (info->info_bytes >> 8) & 0xff;
> +	}
> +}
> +
> +static int meson_nfc_ecc_correct(struct mtd_info *mtd,
> +						struct nand_chip *chip)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	struct meson_nfc_info_format *info;
> +	u32 bitflips = 0, i;
> +	u8 zero_cnt;
> +
> +	for (i = 0; i < nfc->param.ecc_step; i++) {
> +		info = nfc_info_ptr(nfc, i);
> +		if (info->ecc.eccerr_cnt == 0x3f) {
> +			zero_cnt = info->zero_cnt & 0x3f;
> +			if (nfc->param.rand_mode
> +				&& (zero_cnt < nfc->param.ecc_max))
> +				return ECC_CHECK_RETURN_FF;
> +			mtd->ecc_stats.failed++;
> +			continue;
> +		}
> +		mtd->ecc_stats.corrected += info->ecc.eccerr_cnt;
> +		bitflips = max_t(u32, bitflips, info->ecc.eccerr_cnt);
> +	}
> +
> +	return bitflips;
> +}
> +
> +static inline u8 meson_nfc_read_byte(struct mtd_info *mtd)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	u32 cmd;
> +
> +	cmd = nfc->param.chip_select | NFC_CMD_DRD | 0;
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +
> +	meson_nfc_cmd_idle(nfc, 0);
> +	meson_nfc_cmd_idle(nfc, 0);
> +
> +	meson_nfc_wait_cmd_finish(nfc, 1000);
> +
> +	return readb(nfc->reg_base + NFC_REG_BUF);
> +}
> +
> +static void meson_nfc_read_buf(struct mtd_info *mtd, u8 *buf, int len)
> +{
> +	int i;
> +
> +	for (i = 0; i < len; i++)
> +		buf[i] = meson_nfc_read_byte(mtd);
> +}
> +
> +static void meson_nfc_write_byte(struct mtd_info *mtd, u8 byte)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
> +	u32 cmd;
> +
> +	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
> +
> +	cmd = nfc->param.chip_select | NFC_CMD_DWR | (byte & 0xff);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +
> +	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
> +	meson_nfc_cmd_idle(nfc, 0);
> +
> +	meson_nfc_wait_cmd_finish(nfc, 1000);
> +}
> +
> +static void meson_nfc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
> +{
> +	int i;
> +
> +	for (i = 0; i < len; i++)
> +		meson_nfc_write_byte(mtd, buf[i]);
> +}
> +
> +static int meson_nfc_write_page_sub(struct mtd_info *mtd,
> +		struct nand_chip *chip, const u8 *buf, int page, int raw)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	dma_addr_t daddr, iaddr;
> +	u32 cmd;
> +	int ret;
> +
> +	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
> +
> +	daddr = dma_map_single(nfc->dev, (void *)nfc->data_buf,
> +			mtd->writesize + mtd->oobsize, DMA_TO_DEVICE);
> +	ret = dma_mapping_error(nfc->dev, daddr);
> +	if (ret) {
> +		dev_err(nfc->dev, "dma mapping error\n");
> +		return -EINVAL;
> +	}
> +
> +	iaddr = dma_map_single(nfc->dev, (void *)nfc->info_buf,
> +			nfc->param.ecc_step * PER_INFO_BYTE, DMA_TO_DEVICE);
> +	ret = dma_mapping_error(nfc->dev, iaddr);
> +	if (ret) {
> +		dev_err(nfc->dev, "dma mapping error\n");
> +		return -EINVAL;
> +	}
> +
> +	cmd = GENCMDDADDRL(NFC_CMD_ADL, daddr);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +	cmd = GENCMDDADDRH(NFC_CMD_ADH, daddr);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +
> +	cmd = GENCMDIADDRL(NFC_CMD_AIL, iaddr);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +	cmd = GENCMDIADDRH(NFC_CMD_AIH, iaddr);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +
> +	meson_nfc_cmd_seed(nfc, page);
> +
> +	meson_nfc_cmd_m2n(nfc, raw);
> +
> +	ret = meson_nfc_wait_dma_finish(nfc);
> +
> +	dma_unmap_single(nfc->dev, daddr,
> +			mtd->writesize + mtd->oobsize, DMA_TO_DEVICE);
> +	dma_unmap_single(nfc->dev, iaddr,
> +			nfc->param.ecc_step * PER_INFO_BYTE, DMA_TO_DEVICE);
> +
> +	return nand_prog_page_end_op(chip);
> +}
> +
> +static int meson_nfc_write_page_raw(struct mtd_info *mtd,
> +	struct nand_chip *chip, const u8 *buf, int oob_required, int page)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	u8 *oob_buf = chip->oob_poi;
> +
> +	meson_nfc_format_data_oob(nfc, buf, oob_buf);
> +
> +	return meson_nfc_write_page_sub(mtd, chip, nfc->data_buf, page, 1);
> +}
> +
> +static int meson_nfc_write_page_hwecc(struct mtd_info *mtd,
> +				    struct nand_chip *chip, const u8 *buf,
> +				    int oob_required, int page)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	u8 *oob_buf = chip->oob_poi;
> +
> +	memcpy(nfc->data_buf, buf, mtd->writesize);
> +	meson_nfc_set_user_byte(mtd, chip, oob_buf);
> +
> +	return meson_nfc_write_page_sub(mtd, chip, nfc->data_buf, page, 0);
> +}
> +
> +static void meson_nfc_check_ecc_pages_valid(struct meson_nfc *nfc, int raw)
> +{
> +	struct meson_nfc_info_format *info;
> +	int neccpages, i;
> +
> +	neccpages = raw ? 1 : nfc->param.ecc_step;
> +
> +	for (i = 0; i < neccpages; i++) {
> +		info = nfc_info_ptr(nfc, neccpages - 1);
> +		if (info->ecc.completed == 0)
> +			dev_err(nfc->dev, "seems eccpage is invalid\n");
> +	}
> +}
> +
> +static int meson_nfc_read_page_sub(struct mtd_info *mtd,
> +	struct nand_chip *chip, const u8 *buf, int page, int raw)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	dma_addr_t daddr, iaddr;
> +	u32 cmd;
> +	int ret;
> +
> +	nand_read_page_op(chip, page, 0, NULL, 0);
> +
> +	daddr = dma_map_single(nfc->dev, nfc->data_buf,
> +			mtd->writesize + mtd->oobsize, DMA_FROM_DEVICE);
> +	ret = dma_mapping_error(nfc->dev, daddr);
> +	if (ret) {
> +		dev_err(nfc->dev, "dma mapping error\n");
> +		return -EINVAL;
> +	}
> +
> +	iaddr = dma_map_single(nfc->dev, nfc->info_buf,
> +			nfc->param.ecc_step * PER_INFO_BYTE, DMA_FROM_DEVICE);
> +	ret = dma_mapping_error(nfc->dev, iaddr);
> +	if (ret) {
> +		dev_err(nfc->dev, "dma mapping error\n");
> +		return -EINVAL;
> +	}
> +
> +	cmd = GENCMDDADDRL(NFC_CMD_ADL, daddr);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +	cmd = GENCMDDADDRH(NFC_CMD_ADH, daddr);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +
> +	cmd = GENCMDIADDRL(NFC_CMD_AIL, iaddr);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +	cmd = GENCMDIADDRH(NFC_CMD_AIH, iaddr);
> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
> +
> +	meson_nfc_cmd_seed(nfc, page);
> +
> +	meson_nfc_cmd_n2m(nfc, raw);
> +
> +	ret = meson_nfc_wait_dma_finish(nfc);
> +
> +	meson_nfc_queue_rb(nfc);
> +
> +	meson_nfc_check_ecc_pages_valid(nfc, raw);
> +
> +	dma_unmap_single(nfc->dev, daddr,
> +			mtd->writesize + mtd->oobsize, DMA_FROM_DEVICE);
> +	dma_unmap_single(nfc->dev, iaddr,
> +			nfc->param.ecc_step * PER_INFO_BYTE, DMA_FROM_DEVICE);
> +
> +	return ret;
> +}
> +
> +static int meson_nfc_read_page_raw(struct mtd_info *mtd,
> +	struct nand_chip *chip, u8 *buf, int oob_required, int page)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	u8 *oob_buf = chip->oob_poi;
> +	int ret;
> +
> +	ret = meson_nfc_read_page_sub(mtd, chip, nfc->data_buf, page, 1);
> +	if (ret)
> +		return ret;
> +
> +	meson_nfc_prase_data_oob(nfc, buf, oob_buf);
> +
> +	return 0;
> +}
> +
> +static int meson_nfc_read_page_hwecc(struct mtd_info *mtd,
> +	struct nand_chip *chip, u8 *buf, int oob_required, int page)
> +{
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	u8 *oob_buf = chip->oob_poi;
> +	int ret;
> +
> +	ret = meson_nfc_read_page_sub(mtd, chip, nfc->data_buf, page, 0);
> +	if (ret)
> +		return ret;
> +
> +	meson_nfc_get_user_byte(mtd, chip, oob_buf);
> +
> +	ret = meson_nfc_ecc_correct(mtd, chip);
> +	if (ret == ECC_CHECK_RETURN_FF) {
> +		if (buf)
> +			memset(buf, 0xff, mtd->writesize);
> +
> +		memset(oob_buf, 0xff, mtd->oobsize);
> +		return 0;
> +	}
> +	if (buf && (buf != nfc->data_buf))
> +		memcpy(buf, nfc->data_buf, mtd->writesize);
> +
> +	return ret;
> +}
> +
> +static int meson_nfc_read_oob_raw(struct mtd_info *mtd,
> +				struct nand_chip *chip, int page)
> +{
> +	return meson_nfc_read_page_raw(mtd, chip, NULL, 1, page);
> +}
> +
> +static int meson_nfc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
> +				int page)
> +{
> +	return meson_nfc_read_page_hwecc(mtd, chip, NULL, 1, page);
> +}
> +
> +static int meson_ooblayout_ecc(struct mtd_info *mtd, int section,
> +				  struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +	int free_oob;
> +
> +	if (section > chip->ecc.steps)

	if (section >= chip->ecc.steps)

> +		return -ERANGE;
> +
> +	free_oob = nfc->param.oob_mode ? 16 : (chip->ecc.steps * 2);

Hm, are you sure all free OOB bytes are placed at the beginning of the
OOB buffer? Shouldn't it be section * 2 instead of chip->ecc.steps * 2?

	

> +	oobregion->offset = section * chip->ecc.bytes + free_oob;
> +	oobregion->length = chip->ecc.bytes;
> +
> +	return 0;
> +}
> +
> +static int meson_ooblayout_free(struct mtd_info *mtd, int section,
> +				   struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
> +
> +	if (section > chip->ecc.steps)

	if (section >= chip->ecc.steps)

> +		return -ERANGE;
> +
> +	oobregion->offset = 0;
> +	oobregion->length = nfc->param.oob_mode ? 16 : (chip->ecc.steps * 2);
> +
> +	return 0;
> +}
> +
> +static const struct mtd_ooblayout_ops meson_ooblayout_ops = {
> +	.ecc = meson_ooblayout_ecc,
> +	.free = meson_ooblayout_free,
> +};
> +
> +static int meson_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
> +{
> +	struct nand_chip *nand = mtd_to_nand(mtd);
> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
> +	struct meson_nand_ecc *meson_ecc = nfc->data->ecc;
> +	int num = nfc->data->ecc_num;
> +	int nsectors, i, bytes;
> +
> +	/* support only ecc hw mode */
> +	if (nand->ecc.mode != NAND_ECC_HW) {

Given that you support raw accesses, I'm pretty sure you can support
ECC_NONE, ECC_SOFT and ECC_ON_DIE with zero effort.

> +		dev_err(dev, "ecc.mode not supported\n");
> +		return -EINVAL;
> +	}
> +
> +	if (!nand->ecc.size || !nand->ecc.strength) {
> +		/* use datasheet requirements */
> +		nand->ecc.strength = nand->ecc_strength_ds;
> +		nand->ecc.size = nand->ecc_step_ds;
> +	}
> +
> +	if (nand->ecc.options & NAND_ECC_MAXIMIZE) {
> +		nand->ecc.size = 1024;
> +		nsectors = mtd->writesize / nand->ecc.size;
> +
> +		/* Reserve 2 bytes for each ecc page */
> +		if (meson_chip->user_mode == NFC_USER2_OOB_BYTES)
> +			bytes = mtd->oobsize - 2 * nsectors;
> +		else
> +			bytes = mtd->oobsize - 16;
> +
> +		bytes /= nsectors;
> +
> +		/* and bytes has to be even. */
> +		if (bytes % 2)
> +			bytes--;
> +
> +		nand->ecc.strength = bytes * 8 / fls(8 * nand->ecc.size);
> +	} else {
> +		if (nand->ecc.strength > meson_ecc[num - 1].strength) {
> +			dev_err(dev, "not support ecc strength\n");
> +			return -EINVAL;
> +		}
> +	}
> +
> +	for (i = 0; i < num; i++) {
> +		if ((meson_ecc[i].strength == 0xff)
> +			|| (nand->ecc.strength < meson_ecc[i].strength))
> +			break;
> +	}
> +
> +	if (!i) {
> +		nand->ecc.strength = 0;
> +	} else {
> +		nand->ecc.strength = meson_ecc[i - 1].strength;
> +		nand->ecc.bytes = meson_ecc[i - 1].parity;
> +	}
> +
> +	meson_chip->bch_mode = meson_ecc[i - 1].bch;
> +
> +	if (nand->ecc.size != 512 && nand->ecc.size != 1024)
> +		return -EINVAL;
> +
> +	nsectors = mtd->writesize / nand->ecc.size;
> +	bytes =(meson_chip->user_mode == NFC_USER2_OOB_BYTES) ? nsectors * 2 : 16;
> +	if (mtd->oobsize < (nand->ecc.bytes * nsectors + bytes))
> +		return -EINVAL;

It's probably worth looking at what is being proposed here [2] for the
ECC config selection logic.

> +
> +	return 0;
> +}
> +
> +static const char * sd_emmc_ext_clk0_parent_names[MUX_CLK_NUM_PARENTS];
> +
> +static struct clk_regmap sd_emmc_c_ext_clk0_sel = {
> +	.data = &(struct clk_regmap_mux_data){
> +		.offset = SD_EMMC_CLOCK,
> +		.mask = 0x3,
> +		.shift = 6,
> +	},
> +	.hw.init = &(struct clk_init_data) {
> +		.name = "sd_emmc_c_nand_clk_mux",
> +		.ops = &clk_regmap_mux_ops,
> +		.parent_names = sd_emmc_ext_clk0_parent_names,
> +		.num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
> +		.flags = CLK_SET_RATE_PARENT,
> +	},
> +};
> +
> +static struct clk_regmap sd_emmc_c_ext_clk0_div = {
> +	.data = &(struct clk_regmap_div_data){
> +		.offset = SD_EMMC_CLOCK,
> +		.shift = 0,
> +		.width = 6,
> +		.flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
> +	},
> +	.hw.init = &(struct clk_init_data) {
> +		.name = "sd_emmc_c_nand_clk_div",
> +		.ops = &clk_regmap_divider_ops,
> +		.parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
> +		.num_parents = 1,
> +		.flags = CLK_SET_RATE_PARENT,
> +	},
> +};
> +
> +static int meson_nfc_clk_init(struct meson_nfc *nfc)
> +{
> +	struct clk_regmap *mux = &sd_emmc_c_ext_clk0_sel;
> +	struct clk_regmap *div = &sd_emmc_c_ext_clk0_div;
> +	struct clk *clk;
> +	int i, ret;
> +
> +	/* request core clock */
> +	nfc->core_clk = devm_clk_get(nfc->dev, "core");
> +	if (IS_ERR(nfc->core_clk)) {
> +		dev_err(nfc->dev, "failed to get core clk\n");
> +		return PTR_ERR(nfc->core_clk);
> +	}
> +
> +	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
> +	regmap_update_bits(nfc->reg_clk, 0,
> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK,
> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK);
> +
> +	/* get the mux parents */
> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
> +		char name[16];
> +
> +		snprintf(name, sizeof(name), "clkin%d", i);
> +		clk = devm_clk_get(nfc->dev, name);
> +		if (IS_ERR(clk)) {
> +			if (clk != ERR_PTR(-EPROBE_DEFER))
> +				dev_err(nfc->dev, "Missing clock %s\n", name);
> +			return PTR_ERR(clk);
> +		}
> +
> +		sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
> +	}
> +
> +	mux->map = nfc->reg_clk;
> +	clk = devm_clk_register(nfc->dev, &mux->hw);
> +	if (WARN_ON(IS_ERR(clk)))
> +		return PTR_ERR(clk);
> +
> +	div->map = nfc->reg_clk;
> +	nfc->device_clk = devm_clk_register(nfc->dev, &div->hw);
> +	if (WARN_ON(IS_ERR(nfc->device_clk)))
> +		return PTR_ERR(nfc->device_clk);
> +
> +	ret = clk_prepare_enable(nfc->core_clk);
> +	if (ret) {
> +		dev_err(nfc->dev, "failed to enable core clk\n");
> +		return ret;
> +	}
> +
> +	ret = clk_prepare_enable(nfc->device_clk);
> +	if (ret) {
> +		dev_err(nfc->dev, "failed to enable device clk\n");
> +		clk_disable_unprepare(nfc->core_clk);
> +		return ret;
> +	}
> +
> +	return 0;
> +}


As said above, I don't like having a clk driver here, especially since
the registers you're accessing are not part of the NAND controller
registers. Please try to create a driver in drivers/clk/ for that.

> +
> +static void meson_nfc_disable_clk(struct meson_nfc *nfc)
> +{
> +	clk_disable_unprepare(nfc->device_clk);
> +	clk_disable_unprepare(nfc->core_clk);
> +}
> +
> +static int meson_nfc_buffer_init(struct mtd_info *mtd)
> +{
> +	struct nand_chip *nand = mtd_to_nand(mtd);
> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
> +	struct device *dev = nfc->dev;
> +	int info_bytes, page_bytes;
> +	int nsectors;
> +
> +	nsectors = mtd->writesize / nand->ecc.size;
> +	info_bytes = nsectors * PER_INFO_BYTE;
> +	page_bytes = mtd->writesize + mtd->oobsize;
> +
> +	if ((meson_chip->data_buf) && (meson_chip->info_buf))
> +		return 0;
> +
> +	meson_chip->data_buf = devm_kzalloc(dev, page_bytes, GFP_KERNEL);
> +	if (!meson_chip->data_buf)
> +		return  -ENOMEM;
> +
> +	meson_chip->info_buf = devm_kzalloc(dev, info_bytes, GFP_KERNEL);
> +	if (!meson_chip->info_buf)
> +		return  -ENOMEM;

You're doing DMA on those buffers, and devm_kzalloc() is not
DMA-friendly (returned buffers are not aligned on a cache line). Also,
you don't have to allocate your own buffers because the core already
allocate them (chip->data_buf, chip->oob_poi). All you need to do is
set the NAND_USE_BOUNCE_BUFFER flag in chip->options to make sure
you're always passed a DMA-able buffer.

> +
> +	return 0;
> +}
> +
> +static int meson_nfc_calc_set_timing(struct meson_nfc *nfc,
> +				int rc_min, int rea_max, int rhoh_min)
> +{
> +	int div, bt_min, bt_max, bus_timing;
> +	int ret;
> +
> +	div = DIV_ROUND_UP((rc_min / 1000), NFC_CLK_CYCLE);
> +	ret = clk_set_rate(nfc->device_clk, 1000000000 / div);
> +	if (ret) {
> +		dev_err(nfc->dev, "failed to set nand clock rate\n");
> +		return ret;
> +	}
> +
> +	bt_min = (rea_max + NFC_DEFAULT_DELAY) / div;
> +	bt_max = (NFC_DEFAULT_DELAY + rhoh_min + rc_min / 2) / div;
> +
> +	bt_min = DIV_ROUND_UP(bt_min, 1000);
> +	bt_max = DIV_ROUND_UP(bt_max, 1000);
> +
> +	if (bt_max < bt_min)
> +		return -EINVAL;
> +
> +	bus_timing = (bt_min + bt_max) / 2 + 1;
> +
> +	writel((1 << 21), nfc->reg_base + NFC_REG_CFG);
> +	writel((NFC_CLK_CYCLE - 1) | (bus_timing << 5),
> +				nfc->reg_base + NFC_REG_CFG);
> +
> +	writel((1 << 31), nfc->reg_base + NFC_REG_CMD);
> +
> +	return 0;
> +}
> +
> +static int meson_nfc_setup_data_interface(struct mtd_info *mtd, int csline,
> +				const struct nand_data_interface *conf)
> +{
> +	struct nand_chip *nand = mtd_to_nand(mtd);
> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
> +	const struct nand_sdr_timings *timings;
> +
> +	timings = nand_get_sdr_timings(conf);
> +	if (IS_ERR(timings))
> +		return -ENOTSUPP;
> +
> +	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
> +		return 0;
> +
> +	meson_nfc_calc_set_timing(nfc, timings->tRC_min,
> +				timings->tREA_max, timings->tRHOH_min);
> +
> +	return 0;
> +}
> +
> +static int meson_nfc_get_nand_chip_dts(struct meson_nfc *nfc,
> +		struct meson_nfc_nand_chip *chip, struct device_node *np)
> +{
> +	struct device *dev = nfc->dev;
> +
> +	if (of_property_read_u32(np, "reg", &chip->cs)) {
> +		dev_err(dev, "can not get ce number\n");
> +		return -EINVAL;
> +	}
> +
> +	if (chip->cs > MAX_CE_NUM) {
> +		dev_err(dev, "ce number is beyond\n");
> +		return -EINVAL;
> +	}
> +
> +	if (of_property_read_u32(np, "meson-nand-user-mode", &chip->user_mode)) {
> +		dev_err(dev, "can not get user oob mode\n");
> +		return -EINVAL;
> +	}
> +
> +	if ((chip->user_mode != NFC_USER2_OOB_BYTES)
> +			|| (chip->user_mode != NFC_USER16_OOB_BYTES))
> +		chip->user_mode = NFC_USER2_OOB_BYTES;
> +
> +	if (of_property_read_u32(np, "meson-nand-ran-mode", &chip->rand_mode)) {
> +		dev_err(dev, "can not get scramble mode\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int meson_nfc_nand_chip_init(struct device *dev, struct meson_nfc *nfc,
> +				  struct device_node *np)
> +{
> +	struct meson_nfc_nand_chip *chip;
> +	struct nand_chip *nand;
> +	struct mtd_info *mtd;
> +	int ret;
> +
> +	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
> +	if (!chip)
> +		return -ENOMEM;
> +
> +	ret = meson_nfc_get_nand_chip_dts(nfc, chip, np);

Is there a really a need for putting this code in a separate function?
Do you plan to support non-DT platforms?

> +	if (ret)
> +		return ret;
> +
> +	nand = &chip->nand;
> +	nand_set_flash_node(nand, np);
> +	nand_set_controller_data(nand, nfc);
> +
> +	nand->options |= NAND_USE_BOUNCE_BUFFER;
> +	nand->select_chip = meson_nfc_select_chip;
> +	nand->write_byte = meson_nfc_write_byte;
> +	nand->write_buf = meson_nfc_write_buf;
> +	nand->read_byte = meson_nfc_read_byte;
> +	nand->read_buf = meson_nfc_read_buf;
> +	nand->cmd_ctrl = meson_nfc_cmd_ctrl;

->{write,read}_byte(), ->{write,read}_buf(), ->cmd_ctrl() should be
replaced by ->exec_op().

> +	nand->setup_data_interface = meson_nfc_setup_data_interface;
> +
> +	nand->chip_delay = 200;

This should not be needed if you implement ->exec_op() and
->setup_data_interface().

> +	nand->ecc.mode = NAND_ECC_HW;
> +
> +	nand->ecc.write_page_raw = meson_nfc_write_page_raw;
> +	nand->ecc.write_page = meson_nfc_write_page_hwecc;
> +	nand->ecc.write_oob_raw = nand_write_oob_std;
> +	nand->ecc.write_oob = nand_write_oob_std;
> +
> +	nand->ecc.read_page_raw = meson_nfc_read_page_raw;
> +	nand->ecc.read_page = meson_nfc_read_page_hwecc;
> +	nand->ecc.read_oob_raw = meson_nfc_read_oob_raw;
> +	nand->ecc.read_oob = meson_nfc_read_oob;
> +
> +	mtd = nand_to_mtd(nand);
> +	mtd->owner = THIS_MODULE;
> +	mtd->dev.parent = dev;
> +	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
> +				   "%s:nand", dev_name(dev));
> +	if (!mtd->name) {
> +		dev_err(nfc->dev, "Failed to allocate mtd->name\n");
> +		return -ENOMEM;
> +	}

You set the name after nand_scan_ident() and make it conditional (only
if ->name == NULL) so that the label property defined in the DT takes
precedence over the default name. Also, I recommend suffixing this name
with the CS id, just in case you ever need to support connecting several
chips to the same controller. 

> +
> +	mtd_set_ooblayout(mtd, &meson_ooblayout_ops);

We usually assign the OOB layout when we know which ECC engine will be
used. Here that works because you only support ECC_HW, but I think it's
preferable to move that in your ECC init function.

> +
> +	ret = nand_scan_ident(mtd, 1, NULL);
> +	if (ret) {
> +		dev_err(dev, "failed to can ident\n");
> +		return -ENODEV;
> +	}
> +
> +	/* store bbt magic in page, cause OOB is not protected */
> +	if (nand->bbt_options & NAND_BBT_USE_FLASH)
> +		nand->bbt_options |= NAND_BBT_NO_OOB;
> +
> +	nand->options |= NAND_NO_SUBPAGE_WRITE;
> +
> +	ret = meson_nfc_ecc_init(dev, mtd);
> +	if (ret) {
> +		dev_err(dev, "failed to ecc init\n");
> +		return -EINVAL;
> +	}
> +
> +	if (nand->options & NAND_BUSWIDTH_16) {
> +		dev_err(dev, "16bits buswidth not supported");
> +		return -EINVAL;
> +	}
> +
> +	ret = meson_nfc_buffer_init(mtd);
> +	if (ret)
> +		return -ENOMEM;
> +
> +	ret = nand_scan_tail(mtd);
> +	if (ret)
> +		return -ENODEV;
> +
> +	ret = mtd_device_register(mtd, NULL, 0);
> +	if (ret) {
> +		dev_err(dev, "failed to register mtd device: %d\n", ret);
> +		nand_release(mtd);

You should call nand_cleanup() not call nand_release().

> +		return ret;
> +	}
> +
> +	list_add_tail(&chip->node, &nfc->chips);
> +
> +	return 0;
> +}
> +
> +static int meson_nfc_nand_chips_init(struct device *dev, struct meson_nfc *nfc)
> +{
> +	struct device_node *np = dev->of_node;
> +	struct device_node *nand_np;
> +	int ret;
> +
> +	for_each_child_of_node(np, nand_np) {
> +		ret = meson_nfc_nand_chip_init(dev, nfc, nand_np);
> +		if (ret) {
> +			of_node_put(nand_np);

You don't need to call of_node_put(), for_each_child_of_node() will do
that for you.

> +			return ret;

You should remove all chips that have been added in case of error.

> +		}
> +	}
> +	return 0;
> +}
> +
> +static irqreturn_t meson_nfc_irq(int irq, void *id)
> +{
> +	struct meson_nfc *nfc = id;
> +	u32 cfg;
> +
> +	cfg = readl(nfc->reg_base + NFC_REG_CFG);
> +	cfg |= (1 << 21);
> +	writel(cfg, nfc->reg_base + NFC_REG_CFG);
> +
> +	complete(&nfc->completion);
> +	return IRQ_HANDLED;
> +}
> +
> +static const struct meson_nfc_data meson_gxl_data = {
> +	.short_bch	= NFC_ECC_BCH60_1K,
> +	.ecc		= meson_gxl_ecc,
> +	.ecc_num	= ARRAY_SIZE(meson_gxl_ecc),
> +};
> +
> +static const struct meson_nfc_data meson_axg_data = {
> +	.short_bch	= NFC_ECC_BCH8_1K,
> +	.ecc		= meson_axg_ecc,
> +	.ecc_num	= ARRAY_SIZE(meson_axg_ecc),
> +};
> +
> +static const struct of_device_id meson_nfc_id_table[] = {
> +	{
> +		.compatible = "amlogic,meson-gxl-nfc",
> +		.data = &meson_gxl_data,
> +	}, {
> +		.compatible = "amlogic,meson-axg-nfc",
> +		.data = &meson_axg_data,
> +	},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, meson_nfc_id_table);
> +
> +static int meson_nfc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct meson_nfc *nfc;
> +	struct resource *res;
> +	const struct of_device_id *of_nfc_id;
> +	int ret, irq;
> +
> +	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
> +	if (!nfc)
> +		return -ENOMEM;
> +
> +	of_nfc_id = of_match_device(meson_nfc_id_table, &pdev->dev);
> +	if (!of_nfc_id)
> +		return -ENODEV;
> +
> +	nfc->data = (struct meson_nfc_data *)of_nfc_id->data;
> +
> +	spin_lock_init(&nfc->controller.lock);
> +	init_waitqueue_head(&nfc->controller.wq);
> +	INIT_LIST_HEAD(&nfc->chips);
> +
> +	nfc->dev = dev;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(dev, "Failed to nfc reg resource\n");
> +		return -EINVAL;
> +	}
> +
> +	nfc->reg_base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(nfc->reg_base)) {
> +		dev_err(dev, "Failed to lookup nfi reg base\n");
> +		return PTR_ERR(nfc->reg_base);
> +	}
> +
> +	nfc->reg_clk = syscon_regmap_lookup_by_phandle(dev->of_node,
> +							"amlogic,mmc-syscon");
> +	if (IS_ERR(nfc->reg_clk)) {
> +		dev_err(dev, "Failed to lookup clock base\n");
> +		return PTR_ERR(nfc->reg_clk);
> +	}
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0) {
> +		dev_err(dev, "no nfi irq resource\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = meson_nfc_clk_init(nfc);
> +	if (ret) {
> +		dev_err(dev, "failed to initialize nand clk\n");
> +		goto err_clk;
> +	}
> +
> +	ret = devm_request_irq(dev, irq, meson_nfc_irq, 0, dev_name(dev), nfc);
> +	if (ret) {
> +		dev_err(dev, "failed to request nfi irq\n");
> +		ret = -EINVAL;
> +		goto err_clk;
> +	}
> +
> +	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
> +	if (ret) {
> +		dev_err(dev, "failed to set dma mask\n");
> +		goto err_clk;
> +	}
> +
> +	platform_set_drvdata(pdev, nfc);
> +
> +	ret = meson_nfc_nand_chips_init(dev, nfc);
> +	if (ret) {
> +		dev_err(dev, "failed to init nand chips\n");
> +		goto err_clk;
> +	}
> +
> +	meson_nfc_page0_gen(nfc);
> +	return 0;
> +
> +err_clk:
> +	clk_disable_unprepare(nfc->device_clk);
> +	clk_disable_unprepare(nfc->core_clk);

Why not meson_nfc_disable_clk()?

> +
> +	return ret;
> +}
> +
> +static int meson_nfc_remove(struct platform_device *pdev)
> +{
> +	struct meson_nfc *nfc = platform_get_drvdata(pdev);
> +	struct meson_nfc_nand_chip *chip;
> +
> +	while (!list_empty(&nfc->chips)) {
> +		chip = list_first_entry(&nfc->chips, struct meson_nfc_nand_chip,
> +					node);
> +		nand_release(nand_to_mtd(&chip->nand));

Please use mtd_device_unregister() + nand_cleanup(), and check the
return value of mtd_device_unregister() before calling nand_cleanup().

> +		list_del(&chip->node);
> +	}
> +
> +	meson_nfc_disable_clk(nfc);
> +
> +	platform_set_drvdata(pdev, NULL);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver meson_nfc_driver = {
> +	.probe  = meson_nfc_probe,
> +	.remove = meson_nfc_remove,
> +	.driver = {
> +		.name  = "meson_nand",

If you don't mind, I prefer "meson-nand" :-).

> +		.of_match_table = meson_nfc_id_table,
> +	},
> +};
> +

Can you remove this blank line?

> +module_platform_driver(meson_nfc_driver);
> +
> +MODULE_LICENSE("Dual MIT/GPL");
> +MODULE_AUTHOR("Liang Yang <liang.yang@amlogic.com>");
> +MODULE_DESCRIPTION("Amlogic's Meson NAND Flash Controller driver");

I probably missed a lot of other things, but that should be enough to
start working on a v2.

Regards,

Boris

[1]https://elixir.bootlin.com/u-boot/v2018.07-rc2/source/tools/sunxi-spl-image-builder.c
[2]http://patchwork.ozlabs.org/patch/931984/
Kevin Hilman June 27, 2018, 11:33 p.m. | #4
Hi Boris,

Boris Brezillon <boris.brezillon@bootlin.com> writes:

> Hi Yixun,
>
> On Wed, 13 Jun 2018 16:13:14 +0000
> Yixun Lan <yixun.lan@amlogic.com> wrote:
>
>> From: Liang Yang <liang.yang@amlogic.com>
>> 
>> Add initial support for the Amlogic NAND flash controller which found
>> in the Meson-GXBB/GXL/AXG SoCs.
>> 
>> Singed-off-by: Liang Yang <liang.yang@amlogic.com>
>> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>> ---
>>  drivers/mtd/nand/raw/Kconfig      |    8 +
>>  drivers/mtd/nand/raw/Makefile     |    3 +
>>  drivers/mtd/nand/raw/meson_nand.c | 1422 +++++++++++++++++++++++++++++
>>  3 files changed, 1433 insertions(+)
>>  create mode 100644 drivers/mtd/nand/raw/meson_nand.c
>
> Can you run checkpatch.pl --strict and fix the coding style issues?
>
>> 
>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>> index 19a2b283fbbe..b3c17a3ca8f4 100644
>> --- a/drivers/mtd/nand/raw/Kconfig
>> +++ b/drivers/mtd/nand/raw/Kconfig
>> @@ -534,4 +534,12 @@ config MTD_NAND_MTK
>>  	  Enables support for NAND controller on MTK SoCs.
>>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
>>  
>> +config MTD_NAND_MESON
>> +	tristate "Support for NAND flash controller on Amlogic's Meson SoCs"
>> +	depends on ARCH_MESON || COMPILE_TEST
>> +	select COMMON_CLK_REGMAP_MESON
>> +	select MFD_SYSCON
>> +	help
>> +	  Enables support for NAND controller on Amlogic's Meson SoCs.
>> +
>>  endif # MTD_NAND
>> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
>> index 165b7ef9e9a1..cdf6162f38c3 100644
>> --- a/drivers/mtd/nand/raw/Makefile
>> +++ b/drivers/mtd/nand/raw/Makefile
>> @@ -1,5 +1,7 @@
>>  # SPDX-License-Identifier: GPL-2.0
>>  
>> +ccflags-$(CONFIG_MTD_NAND_MESON) += -I$(srctree)/drivers/clk/meson
>
> Please don't do that. If you need to expose common regs, put them
> in include/linux/soc/meson/. I'm also not sure why you need to access
> the clk regs directly. Why can't you expose the MMC/NAND clk as a clk
> provider whose driver would be placed in drivers/clk and which would use
> the mmc syscon. This way the same clk driver could be used for both
> MMC and NAND clk indifferently, and the NAND driver would be much
> simpler.

[...]

>> +
>> +	return 0;
>> +}
>> +
>> +static const char * sd_emmc_ext_clk0_parent_names[MUX_CLK_NUM_PARENTS];
>> +
>> +static struct clk_regmap sd_emmc_c_ext_clk0_sel = {
>> +	.data = &(struct clk_regmap_mux_data){
>> +		.offset = SD_EMMC_CLOCK,
>> +		.mask = 0x3,
>> +		.shift = 6,
>> +	},
>> +	.hw.init = &(struct clk_init_data) {
>> +		.name = "sd_emmc_c_nand_clk_mux",
>> +		.ops = &clk_regmap_mux_ops,
>> +		.parent_names = sd_emmc_ext_clk0_parent_names,
>> +		.num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
>> +		.flags = CLK_SET_RATE_PARENT,
>> +	},
>> +};
>> +
>> +static struct clk_regmap sd_emmc_c_ext_clk0_div = {
>> +	.data = &(struct clk_regmap_div_data){
>> +		.offset = SD_EMMC_CLOCK,
>> +		.shift = 0,
>> +		.width = 6,
>> +		.flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
>> +	},
>> +	.hw.init = &(struct clk_init_data) {
>> +		.name = "sd_emmc_c_nand_clk_div",
>> +		.ops = &clk_regmap_divider_ops,
>> +		.parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
>> +		.num_parents = 1,
>> +		.flags = CLK_SET_RATE_PARENT,
>> +	},
>> +};
>> +
>> +static int meson_nfc_clk_init(struct meson_nfc *nfc)
>> +{
>> +	struct clk_regmap *mux = &sd_emmc_c_ext_clk0_sel;
>> +	struct clk_regmap *div = &sd_emmc_c_ext_clk0_div;
>> +	struct clk *clk;
>> +	int i, ret;
>> +
>> +	/* request core clock */
>> +	nfc->core_clk = devm_clk_get(nfc->dev, "core");
>> +	if (IS_ERR(nfc->core_clk)) {
>> +		dev_err(nfc->dev, "failed to get core clk\n");
>> +		return PTR_ERR(nfc->core_clk);
>> +	}
>> +
>> +	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
>> +	regmap_update_bits(nfc->reg_clk, 0,
>> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK,
>> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK);
>> +
>> +	/* get the mux parents */
>> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
>> +		char name[16];
>> +
>> +		snprintf(name, sizeof(name), "clkin%d", i);
>> +		clk = devm_clk_get(nfc->dev, name);
>> +		if (IS_ERR(clk)) {
>> +			if (clk != ERR_PTR(-EPROBE_DEFER))
>> +				dev_err(nfc->dev, "Missing clock %s\n", name);
>> +			return PTR_ERR(clk);
>> +		}
>> +
>> +		sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
>> +	}
>> +
>> +	mux->map = nfc->reg_clk;
>> +	clk = devm_clk_register(nfc->dev, &mux->hw);
>> +	if (WARN_ON(IS_ERR(clk)))
>> +		return PTR_ERR(clk);
>> +
>> +	div->map = nfc->reg_clk;
>> +	nfc->device_clk = devm_clk_register(nfc->dev, &div->hw);
>> +	if (WARN_ON(IS_ERR(nfc->device_clk)))
>> +		return PTR_ERR(nfc->device_clk);
>> +
>> +	ret = clk_prepare_enable(nfc->core_clk);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "failed to enable core clk\n");
>> +		return ret;
>> +	}
>> +
>> +	ret = clk_prepare_enable(nfc->device_clk);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "failed to enable device clk\n");
>> +		clk_disable_unprepare(nfc->core_clk);
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>
>
> As said above, I don't like having a clk driver here, especially since
> the registers you're accessing are not part of the NAND controller
> registers. Please try to create a driver in drivers/clk/ for that.

We went back and forth on this one on some off-list reviews.

Had we known that the NAND controller was (re)using the clock registers
internal to the MMC IP block from the beginning, we would have written a
clock provider in drivers/clk for this, and shared it.

However, when I wrote the MMC driver[1] (already upstream) along with
the bindings[2], we did not fathom that the internal mux and divider
would be "borrowed" by another device. :(

We only recently found out that the NAND controller "borrows" one of the
MMC clocks, whose registers are inside the MMC range.  Taking the clock
out of the MMC driver and into its own clock-provider implies redoing
the MMC driver, as well as its bindings, which we wanted to avoid
(especially the binding changes.)

We (I can take the blame) decided that since the MMC and NAND are
mutually exclusive (they also share pins), that allowing NAND to reuse
the MMC range would be a good compromise.  The DT still accurately
describes the hardware, but we don't have to throw a large wrench into
the DT bindings just for a newly discovered shared clock.

I agree, it's not the prettiest thing, but when we cannot know the full
details of the hardware when we start, sometimes we end up in a bit of a
mess that requires some compromise.

Kevin

[1] drivers/mmc/host/meson-gx-mmc.c
[2] Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt
Miquel Raynal June 28, 2018, 7 a.m. | #5
Hi Kevin,

On Wed, 27 Jun 2018 16:33:43 -0700, Kevin Hilman <khilman@baylibre.com>
wrote:

> Hi Boris,
> 
> Boris Brezillon <boris.brezillon@bootlin.com> writes:
> 
> > Hi Yixun,
> >
> > On Wed, 13 Jun 2018 16:13:14 +0000
> > Yixun Lan <yixun.lan@amlogic.com> wrote:
> >  
> >> From: Liang Yang <liang.yang@amlogic.com>
> >> 
> >> Add initial support for the Amlogic NAND flash controller which found
> >> in the Meson-GXBB/GXL/AXG SoCs.
> >> 
> >> Singed-off-by: Liang Yang <liang.yang@amlogic.com>
> >> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
> >> ---
> >>  drivers/mtd/nand/raw/Kconfig      |    8 +
> >>  drivers/mtd/nand/raw/Makefile     |    3 +
> >>  drivers/mtd/nand/raw/meson_nand.c | 1422 +++++++++++++++++++++++++++++
> >>  3 files changed, 1433 insertions(+)
> >>  create mode 100644 drivers/mtd/nand/raw/meson_nand.c  
> >
> > Can you run checkpatch.pl --strict and fix the coding style issues?
> >  
> >> 
> >> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> >> index 19a2b283fbbe..b3c17a3ca8f4 100644
> >> --- a/drivers/mtd/nand/raw/Kconfig
> >> +++ b/drivers/mtd/nand/raw/Kconfig
> >> @@ -534,4 +534,12 @@ config MTD_NAND_MTK
> >>  	  Enables support for NAND controller on MTK SoCs.
> >>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
> >>  
> >> +config MTD_NAND_MESON
> >> +	tristate "Support for NAND flash controller on Amlogic's Meson SoCs"
> >> +	depends on ARCH_MESON || COMPILE_TEST
> >> +	select COMMON_CLK_REGMAP_MESON
> >> +	select MFD_SYSCON
> >> +	help
> >> +	  Enables support for NAND controller on Amlogic's Meson SoCs.
> >> +
> >>  endif # MTD_NAND
> >> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
> >> index 165b7ef9e9a1..cdf6162f38c3 100644
> >> --- a/drivers/mtd/nand/raw/Makefile
> >> +++ b/drivers/mtd/nand/raw/Makefile
> >> @@ -1,5 +1,7 @@
> >>  # SPDX-License-Identifier: GPL-2.0
> >>  
> >> +ccflags-$(CONFIG_MTD_NAND_MESON) += -I$(srctree)/drivers/clk/meson  
> >
> > Please don't do that. If you need to expose common regs, put them
> > in include/linux/soc/meson/. I'm also not sure why you need to access
> > the clk regs directly. Why can't you expose the MMC/NAND clk as a clk
> > provider whose driver would be placed in drivers/clk and which would use
> > the mmc syscon. This way the same clk driver could be used for both
> > MMC and NAND clk indifferently, and the NAND driver would be much
> > simpler.  
> 
> [...]
> 
> >> +
> >> +	return 0;
> >> +}
> >> +
> >> +static const char * sd_emmc_ext_clk0_parent_names[MUX_CLK_NUM_PARENTS];
> >> +
> >> +static struct clk_regmap sd_emmc_c_ext_clk0_sel = {
> >> +	.data = &(struct clk_regmap_mux_data){
> >> +		.offset = SD_EMMC_CLOCK,
> >> +		.mask = 0x3,
> >> +		.shift = 6,
> >> +	},
> >> +	.hw.init = &(struct clk_init_data) {
> >> +		.name = "sd_emmc_c_nand_clk_mux",
> >> +		.ops = &clk_regmap_mux_ops,
> >> +		.parent_names = sd_emmc_ext_clk0_parent_names,
> >> +		.num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
> >> +		.flags = CLK_SET_RATE_PARENT,
> >> +	},
> >> +};
> >> +
> >> +static struct clk_regmap sd_emmc_c_ext_clk0_div = {
> >> +	.data = &(struct clk_regmap_div_data){
> >> +		.offset = SD_EMMC_CLOCK,
> >> +		.shift = 0,
> >> +		.width = 6,
> >> +		.flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
> >> +	},
> >> +	.hw.init = &(struct clk_init_data) {
> >> +		.name = "sd_emmc_c_nand_clk_div",
> >> +		.ops = &clk_regmap_divider_ops,
> >> +		.parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
> >> +		.num_parents = 1,
> >> +		.flags = CLK_SET_RATE_PARENT,
> >> +	},
> >> +};
> >> +
> >> +static int meson_nfc_clk_init(struct meson_nfc *nfc)
> >> +{
> >> +	struct clk_regmap *mux = &sd_emmc_c_ext_clk0_sel;
> >> +	struct clk_regmap *div = &sd_emmc_c_ext_clk0_div;
> >> +	struct clk *clk;
> >> +	int i, ret;
> >> +
> >> +	/* request core clock */
> >> +	nfc->core_clk = devm_clk_get(nfc->dev, "core");
> >> +	if (IS_ERR(nfc->core_clk)) {
> >> +		dev_err(nfc->dev, "failed to get core clk\n");
> >> +		return PTR_ERR(nfc->core_clk);
> >> +	}
> >> +
> >> +	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
> >> +	regmap_update_bits(nfc->reg_clk, 0,
> >> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK,
> >> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK);
> >> +
> >> +	/* get the mux parents */
> >> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
> >> +		char name[16];
> >> +
> >> +		snprintf(name, sizeof(name), "clkin%d", i);
> >> +		clk = devm_clk_get(nfc->dev, name);
> >> +		if (IS_ERR(clk)) {
> >> +			if (clk != ERR_PTR(-EPROBE_DEFER))
> >> +				dev_err(nfc->dev, "Missing clock %s\n", name);
> >> +			return PTR_ERR(clk);
> >> +		}
> >> +
> >> +		sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
> >> +	}
> >> +
> >> +	mux->map = nfc->reg_clk;
> >> +	clk = devm_clk_register(nfc->dev, &mux->hw);
> >> +	if (WARN_ON(IS_ERR(clk)))
> >> +		return PTR_ERR(clk);
> >> +
> >> +	div->map = nfc->reg_clk;
> >> +	nfc->device_clk = devm_clk_register(nfc->dev, &div->hw);
> >> +	if (WARN_ON(IS_ERR(nfc->device_clk)))
> >> +		return PTR_ERR(nfc->device_clk);
> >> +
> >> +	ret = clk_prepare_enable(nfc->core_clk);
> >> +	if (ret) {
> >> +		dev_err(nfc->dev, "failed to enable core clk\n");
> >> +		return ret;
> >> +	}
> >> +
> >> +	ret = clk_prepare_enable(nfc->device_clk);
> >> +	if (ret) {
> >> +		dev_err(nfc->dev, "failed to enable device clk\n");
> >> +		clk_disable_unprepare(nfc->core_clk);
> >> +		return ret;
> >> +	}
> >> +
> >> +	return 0;
> >> +}  
> >
> >
> > As said above, I don't like having a clk driver here, especially since
> > the registers you're accessing are not part of the NAND controller
> > registers. Please try to create a driver in drivers/clk/ for that.  
> 
> We went back and forth on this one on some off-list reviews.
> 
> Had we known that the NAND controller was (re)using the clock registers
> internal to the MMC IP block from the beginning, we would have written a
> clock provider in drivers/clk for this, and shared it.
> 
> However, when I wrote the MMC driver[1] (already upstream) along with
> the bindings[2], we did not fathom that the internal mux and divider
> would be "borrowed" by another device. :(
> 
> We only recently found out that the NAND controller "borrows" one of the
> MMC clocks, whose registers are inside the MMC range.  Taking the clock
> out of the MMC driver and into its own clock-provider implies redoing
> the MMC driver, as well as its bindings, which we wanted to avoid
> (especially the binding changes.)
> 
> We (I can take the blame) decided that since the MMC and NAND are
> mutually exclusive (they also share pins), that allowing NAND to reuse
> the MMC range would be a good compromise.  The DT still accurately
> describes the hardware, but we don't have to throw a large wrench into
> the DT bindings just for a newly discovered shared clock.
> 
> I agree, it's not the prettiest thing, but when we cannot know the full
> details of the hardware when we start, sometimes we end up in a bit of a
> mess that requires some compromise.

I totally understand your situation but as MMC and NAND are mutually
exclusive, how is this a problem to have a dedicated clock driver used
only by the NAND controller (as maybe a first step)? I mean, if you
don't change the MMC bindings, then the MMC driver will still use its
own 'local' clock driver, right? I don't know if you can have two
nodes reserving the same address range though.


> 
> Kevin
> 
> [1] drivers/mmc/host/meson-gx-mmc.c
> [2] Documentation/devicetree/bindings/mmc/amlogic,meson-gx.txt                                                                                                       


Thanks,
Miquèl
Kevin Hilman June 28, 2018, 11:45 p.m. | #6
Hi Miquel,

Miquel Raynal <miquel.raynal@bootlin.com> writes:

> On Wed, 27 Jun 2018 16:33:43 -0700, Kevin Hilman <khilman@baylibre.com>
> wrote:
>
>> Hi Boris,
>> 
>> Boris Brezillon <boris.brezillon@bootlin.com> writes:
>> 
>> > Hi Yixun,
>> >
>> > On Wed, 13 Jun 2018 16:13:14 +0000
>> > Yixun Lan <yixun.lan@amlogic.com> wrote:
>> >  
>> >> From: Liang Yang <liang.yang@amlogic.com>
>> >> 
>> >> Add initial support for the Amlogic NAND flash controller which found
>> >> in the Meson-GXBB/GXL/AXG SoCs.
>> >> 
>> >> Singed-off-by: Liang Yang <liang.yang@amlogic.com>
>> >> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>> >> ---
>> >>  drivers/mtd/nand/raw/Kconfig      |    8 +
>> >>  drivers/mtd/nand/raw/Makefile     |    3 +
>> >>  drivers/mtd/nand/raw/meson_nand.c | 1422 +++++++++++++++++++++++++++++
>> >>  3 files changed, 1433 insertions(+)
>> >>  create mode 100644 drivers/mtd/nand/raw/meson_nand.c  
>> >
>> > Can you run checkpatch.pl --strict and fix the coding style issues?
>> >  
>> >> 
>> >> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>> >> index 19a2b283fbbe..b3c17a3ca8f4 100644
>> >> --- a/drivers/mtd/nand/raw/Kconfig
>> >> +++ b/drivers/mtd/nand/raw/Kconfig
>> >> @@ -534,4 +534,12 @@ config MTD_NAND_MTK
>> >>  	  Enables support for NAND controller on MTK SoCs.
>> >>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
>> >>  
>> >> +config MTD_NAND_MESON
>> >> +	tristate "Support for NAND flash controller on Amlogic's Meson SoCs"
>> >> +	depends on ARCH_MESON || COMPILE_TEST
>> >> +	select COMMON_CLK_REGMAP_MESON
>> >> +	select MFD_SYSCON
>> >> +	help
>> >> +	  Enables support for NAND controller on Amlogic's Meson SoCs.
>> >> +
>> >>  endif # MTD_NAND
>> >> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
>> >> index 165b7ef9e9a1..cdf6162f38c3 100644
>> >> --- a/drivers/mtd/nand/raw/Makefile
>> >> +++ b/drivers/mtd/nand/raw/Makefile
>> >> @@ -1,5 +1,7 @@
>> >>  # SPDX-License-Identifier: GPL-2.0
>> >>  
>> >> +ccflags-$(CONFIG_MTD_NAND_MESON) += -I$(srctree)/drivers/clk/meson  
>> >
>> > Please don't do that. If you need to expose common regs, put them
>> > in include/linux/soc/meson/. I'm also not sure why you need to access
>> > the clk regs directly. Why can't you expose the MMC/NAND clk as a clk
>> > provider whose driver would be placed in drivers/clk and which would use
>> > the mmc syscon. This way the same clk driver could be used for both
>> > MMC and NAND clk indifferently, and the NAND driver would be much
>> > simpler.  
>> 
>> [...]
>> 
>> >> +
>> >> +	return 0;
>> >> +}
>> >> +
>> >> +static const char * sd_emmc_ext_clk0_parent_names[MUX_CLK_NUM_PARENTS];
>> >> +
>> >> +static struct clk_regmap sd_emmc_c_ext_clk0_sel = {
>> >> +	.data = &(struct clk_regmap_mux_data){
>> >> +		.offset = SD_EMMC_CLOCK,
>> >> +		.mask = 0x3,
>> >> +		.shift = 6,
>> >> +	},
>> >> +	.hw.init = &(struct clk_init_data) {
>> >> +		.name = "sd_emmc_c_nand_clk_mux",
>> >> +		.ops = &clk_regmap_mux_ops,
>> >> +		.parent_names = sd_emmc_ext_clk0_parent_names,
>> >> +		.num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
>> >> +		.flags = CLK_SET_RATE_PARENT,
>> >> +	},
>> >> +};
>> >> +
>> >> +static struct clk_regmap sd_emmc_c_ext_clk0_div = {
>> >> +	.data = &(struct clk_regmap_div_data){
>> >> +		.offset = SD_EMMC_CLOCK,
>> >> +		.shift = 0,
>> >> +		.width = 6,
>> >> +		.flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
>> >> +	},
>> >> +	.hw.init = &(struct clk_init_data) {
>> >> +		.name = "sd_emmc_c_nand_clk_div",
>> >> +		.ops = &clk_regmap_divider_ops,
>> >> +		.parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
>> >> +		.num_parents = 1,
>> >> +		.flags = CLK_SET_RATE_PARENT,
>> >> +	},
>> >> +};
>> >> +
>> >> +static int meson_nfc_clk_init(struct meson_nfc *nfc)
>> >> +{
>> >> +	struct clk_regmap *mux = &sd_emmc_c_ext_clk0_sel;
>> >> +	struct clk_regmap *div = &sd_emmc_c_ext_clk0_div;
>> >> +	struct clk *clk;
>> >> +	int i, ret;
>> >> +
>> >> +	/* request core clock */
>> >> +	nfc->core_clk = devm_clk_get(nfc->dev, "core");
>> >> +	if (IS_ERR(nfc->core_clk)) {
>> >> +		dev_err(nfc->dev, "failed to get core clk\n");
>> >> +		return PTR_ERR(nfc->core_clk);
>> >> +	}
>> >> +
>> >> +	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
>> >> +	regmap_update_bits(nfc->reg_clk, 0,
>> >> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK,
>> >> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK);
>> >> +
>> >> +	/* get the mux parents */
>> >> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
>> >> +		char name[16];
>> >> +
>> >> +		snprintf(name, sizeof(name), "clkin%d", i);
>> >> +		clk = devm_clk_get(nfc->dev, name);
>> >> +		if (IS_ERR(clk)) {
>> >> +			if (clk != ERR_PTR(-EPROBE_DEFER))
>> >> +				dev_err(nfc->dev, "Missing clock %s\n", name);
>> >> +			return PTR_ERR(clk);
>> >> +		}
>> >> +
>> >> +		sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
>> >> +	}
>> >> +
>> >> +	mux->map = nfc->reg_clk;
>> >> +	clk = devm_clk_register(nfc->dev, &mux->hw);
>> >> +	if (WARN_ON(IS_ERR(clk)))
>> >> +		return PTR_ERR(clk);
>> >> +
>> >> +	div->map = nfc->reg_clk;
>> >> +	nfc->device_clk = devm_clk_register(nfc->dev, &div->hw);
>> >> +	if (WARN_ON(IS_ERR(nfc->device_clk)))
>> >> +		return PTR_ERR(nfc->device_clk);
>> >> +
>> >> +	ret = clk_prepare_enable(nfc->core_clk);
>> >> +	if (ret) {
>> >> +		dev_err(nfc->dev, "failed to enable core clk\n");
>> >> +		return ret;
>> >> +	}
>> >> +
>> >> +	ret = clk_prepare_enable(nfc->device_clk);
>> >> +	if (ret) {
>> >> +		dev_err(nfc->dev, "failed to enable device clk\n");
>> >> +		clk_disable_unprepare(nfc->core_clk);
>> >> +		return ret;
>> >> +	}
>> >> +
>> >> +	return 0;
>> >> +}  
>> >
>> >
>> > As said above, I don't like having a clk driver here, especially since
>> > the registers you're accessing are not part of the NAND controller
>> > registers. Please try to create a driver in drivers/clk/ for that.  
>> 
>> We went back and forth on this one on some off-list reviews.
>> 
>> Had we known that the NAND controller was (re)using the clock registers
>> internal to the MMC IP block from the beginning, we would have written a
>> clock provider in drivers/clk for this, and shared it.
>> 
>> However, when I wrote the MMC driver[1] (already upstream) along with
>> the bindings[2], we did not fathom that the internal mux and divider
>> would be "borrowed" by another device. :(
>> 
>> We only recently found out that the NAND controller "borrows" one of the
>> MMC clocks, whose registers are inside the MMC range.  Taking the clock
>> out of the MMC driver and into its own clock-provider implies redoing
>> the MMC driver, as well as its bindings, which we wanted to avoid
>> (especially the binding changes.)
>> 
>> We (I can take the blame) decided that since the MMC and NAND are
>> mutually exclusive (they also share pins), that allowing NAND to reuse
>> the MMC range would be a good compromise.  The DT still accurately
>> describes the hardware, but we don't have to throw a large wrench into
>> the DT bindings just for a newly discovered shared clock.
>> 
>> I agree, it's not the prettiest thing, but when we cannot know the full
>> details of the hardware when we start, sometimes we end up in a bit of a
>> mess that requires some compromise.
>
> I totally understand your situation but as MMC and NAND are mutually
> exclusive, how is this a problem to have a dedicated clock driver used
> only by the NAND controller (as maybe a first step)? I mean, if you
> don't change the MMC bindings, then the MMC driver will still use its
> own 'local' clock driver, right?

Yeah, I think you're right.  That would work too.

> I don't know if you can have two nodes reserving the same address
> range though.

You can, but it's a race who gets to claim the region.

You'd have to have the new clock-controler disabled by default, and have
any boards that use the NAND disable the MMC and enable the clock
controller node.

But I think that should work.

Yixun, can you give this approach a try?

Kevin
Neil Armstrong June 29, 2018, 7:14 a.m. | #7
On 29/06/2018 01:45, Kevin Hilman wrote:
> Hi Miquel,
> 
> Miquel Raynal <miquel.raynal@bootlin.com> writes:
> 
>> On Wed, 27 Jun 2018 16:33:43 -0700, Kevin Hilman <khilman@baylibre.com>
>> wrote:
>>
>>> Hi Boris,
>>>
>>> Boris Brezillon <boris.brezillon@bootlin.com> writes:
>>>
>>>> Hi Yixun,
>>>>
>>>> On Wed, 13 Jun 2018 16:13:14 +0000
>>>> Yixun Lan <yixun.lan@amlogic.com> wrote:
>>>>  
>>>>> From: Liang Yang <liang.yang@amlogic.com>
>>>>>
>>>>> Add initial support for the Amlogic NAND flash controller which found
>>>>> in the Meson-GXBB/GXL/AXG SoCs.
>>>>>
>>>>> Singed-off-by: Liang Yang <liang.yang@amlogic.com>
>>>>> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>>>>> ---
>>>>>  drivers/mtd/nand/raw/Kconfig      |    8 +
>>>>>  drivers/mtd/nand/raw/Makefile     |    3 +
>>>>>  drivers/mtd/nand/raw/meson_nand.c | 1422 +++++++++++++++++++++++++++++
>>>>>  3 files changed, 1433 insertions(+)
>>>>>  create mode 100644 drivers/mtd/nand/raw/meson_nand.c  
>>>>
>>>> Can you run checkpatch.pl --strict and fix the coding style issues?
>>>>  
>>>>>
>>>>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>>>>> index 19a2b283fbbe..b3c17a3ca8f4 100644
>>>>> --- a/drivers/mtd/nand/raw/Kconfig
>>>>> +++ b/drivers/mtd/nand/raw/Kconfig
>>>>> @@ -534,4 +534,12 @@ config MTD_NAND_MTK
>>>>>  	  Enables support for NAND controller on MTK SoCs.
>>>>>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
>>>>>  
>>>>> +config MTD_NAND_MESON
>>>>> +	tristate "Support for NAND flash controller on Amlogic's Meson SoCs"
>>>>> +	depends on ARCH_MESON || COMPILE_TEST
>>>>> +	select COMMON_CLK_REGMAP_MESON
>>>>> +	select MFD_SYSCON
>>>>> +	help
>>>>> +	  Enables support for NAND controller on Amlogic's Meson SoCs.
>>>>> +
>>>>>  endif # MTD_NAND
>>>>> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
>>>>> index 165b7ef9e9a1..cdf6162f38c3 100644
>>>>> --- a/drivers/mtd/nand/raw/Makefile
>>>>> +++ b/drivers/mtd/nand/raw/Makefile
>>>>> @@ -1,5 +1,7 @@
>>>>>  # SPDX-License-Identifier: GPL-2.0
>>>>>  
>>>>> +ccflags-$(CONFIG_MTD_NAND_MESON) += -I$(srctree)/drivers/clk/meson  
>>>>
>>>> Please don't do that. If you need to expose common regs, put them
>>>> in include/linux/soc/meson/. I'm also not sure why you need to access
>>>> the clk regs directly. Why can't you expose the MMC/NAND clk as a clk
>>>> provider whose driver would be placed in drivers/clk and which would use
>>>> the mmc syscon. This way the same clk driver could be used for both
>>>> MMC and NAND clk indifferently, and the NAND driver would be much
>>>> simpler.  
>>>
>>> [...]
>>>
>>>>> +
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>>> +static const char * sd_emmc_ext_clk0_parent_names[MUX_CLK_NUM_PARENTS];
>>>>> +
>>>>> +static struct clk_regmap sd_emmc_c_ext_clk0_sel = {
>>>>> +	.data = &(struct clk_regmap_mux_data){
>>>>> +		.offset = SD_EMMC_CLOCK,
>>>>> +		.mask = 0x3,
>>>>> +		.shift = 6,
>>>>> +	},
>>>>> +	.hw.init = &(struct clk_init_data) {
>>>>> +		.name = "sd_emmc_c_nand_clk_mux",
>>>>> +		.ops = &clk_regmap_mux_ops,
>>>>> +		.parent_names = sd_emmc_ext_clk0_parent_names,
>>>>> +		.num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
>>>>> +		.flags = CLK_SET_RATE_PARENT,
>>>>> +	},
>>>>> +};
>>>>> +
>>>>> +static struct clk_regmap sd_emmc_c_ext_clk0_div = {
>>>>> +	.data = &(struct clk_regmap_div_data){
>>>>> +		.offset = SD_EMMC_CLOCK,
>>>>> +		.shift = 0,
>>>>> +		.width = 6,
>>>>> +		.flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
>>>>> +	},
>>>>> +	.hw.init = &(struct clk_init_data) {
>>>>> +		.name = "sd_emmc_c_nand_clk_div",
>>>>> +		.ops = &clk_regmap_divider_ops,
>>>>> +		.parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
>>>>> +		.num_parents = 1,
>>>>> +		.flags = CLK_SET_RATE_PARENT,
>>>>> +	},
>>>>> +};
>>>>> +
>>>>> +static int meson_nfc_clk_init(struct meson_nfc *nfc)
>>>>> +{
>>>>> +	struct clk_regmap *mux = &sd_emmc_c_ext_clk0_sel;
>>>>> +	struct clk_regmap *div = &sd_emmc_c_ext_clk0_div;
>>>>> +	struct clk *clk;
>>>>> +	int i, ret;
>>>>> +
>>>>> +	/* request core clock */
>>>>> +	nfc->core_clk = devm_clk_get(nfc->dev, "core");
>>>>> +	if (IS_ERR(nfc->core_clk)) {
>>>>> +		dev_err(nfc->dev, "failed to get core clk\n");
>>>>> +		return PTR_ERR(nfc->core_clk);
>>>>> +	}
>>>>> +
>>>>> +	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
>>>>> +	regmap_update_bits(nfc->reg_clk, 0,
>>>>> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK,
>>>>> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK);
>>>>> +
>>>>> +	/* get the mux parents */
>>>>> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
>>>>> +		char name[16];
>>>>> +
>>>>> +		snprintf(name, sizeof(name), "clkin%d", i);
>>>>> +		clk = devm_clk_get(nfc->dev, name);
>>>>> +		if (IS_ERR(clk)) {
>>>>> +			if (clk != ERR_PTR(-EPROBE_DEFER))
>>>>> +				dev_err(nfc->dev, "Missing clock %s\n", name);
>>>>> +			return PTR_ERR(clk);
>>>>> +		}
>>>>> +
>>>>> +		sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
>>>>> +	}
>>>>> +
>>>>> +	mux->map = nfc->reg_clk;
>>>>> +	clk = devm_clk_register(nfc->dev, &mux->hw);
>>>>> +	if (WARN_ON(IS_ERR(clk)))
>>>>> +		return PTR_ERR(clk);
>>>>> +
>>>>> +	div->map = nfc->reg_clk;
>>>>> +	nfc->device_clk = devm_clk_register(nfc->dev, &div->hw);
>>>>> +	if (WARN_ON(IS_ERR(nfc->device_clk)))
>>>>> +		return PTR_ERR(nfc->device_clk);
>>>>> +
>>>>> +	ret = clk_prepare_enable(nfc->core_clk);
>>>>> +	if (ret) {
>>>>> +		dev_err(nfc->dev, "failed to enable core clk\n");
>>>>> +		return ret;
>>>>> +	}
>>>>> +
>>>>> +	ret = clk_prepare_enable(nfc->device_clk);
>>>>> +	if (ret) {
>>>>> +		dev_err(nfc->dev, "failed to enable device clk\n");
>>>>> +		clk_disable_unprepare(nfc->core_clk);
>>>>> +		return ret;
>>>>> +	}
>>>>> +
>>>>> +	return 0;
>>>>> +}  
>>>>
>>>>
>>>> As said above, I don't like having a clk driver here, especially since
>>>> the registers you're accessing are not part of the NAND controller
>>>> registers. Please try to create a driver in drivers/clk/ for that.  
>>>
>>> We went back and forth on this one on some off-list reviews.
>>>
>>> Had we known that the NAND controller was (re)using the clock registers
>>> internal to the MMC IP block from the beginning, we would have written a
>>> clock provider in drivers/clk for this, and shared it.
>>>
>>> However, when I wrote the MMC driver[1] (already upstream) along with
>>> the bindings[2], we did not fathom that the internal mux and divider
>>> would be "borrowed" by another device. :(
>>>
>>> We only recently found out that the NAND controller "borrows" one of the
>>> MMC clocks, whose registers are inside the MMC range.  Taking the clock
>>> out of the MMC driver and into its own clock-provider implies redoing
>>> the MMC driver, as well as its bindings, which we wanted to avoid
>>> (especially the binding changes.)
>>>
>>> We (I can take the blame) decided that since the MMC and NAND are
>>> mutually exclusive (they also share pins), that allowing NAND to reuse
>>> the MMC range would be a good compromise.  The DT still accurately
>>> describes the hardware, but we don't have to throw a large wrench into
>>> the DT bindings just for a newly discovered shared clock.
>>>
>>> I agree, it's not the prettiest thing, but when we cannot know the full
>>> details of the hardware when we start, sometimes we end up in a bit of a
>>> mess that requires some compromise.
>>
>> I totally understand your situation but as MMC and NAND are mutually
>> exclusive, how is this a problem to have a dedicated clock driver used
>> only by the NAND controller (as maybe a first step)? I mean, if you
>> don't change the MMC bindings, then the MMC driver will still use its
>> own 'local' clock driver, right?
> 
> Yeah, I think you're right.  That would work too.
> 
>> I don't know if you can have two nodes reserving the same address
>> range though.

The idea was to override the mmc node by "syscon" when the board is in the
NAND case, since the eMMC controller won't be usable in this case anyway.

Neil

> 
> You can, but it's a race who gets to claim the region.
> 
> You'd have to have the new clock-controler disabled by default, and have
> any boards that use the NAND disable the MMC and enable the clock
> controller node.
> 
> But I think that should work.
> 
> Yixun, can you give this approach a try?
> 
> Kevin
>
Yixun Lan July 2, 2018, 7:17 a.m. | #8
HI Kevin

On 06/29/18 07:45, Kevin Hilman wrote:
> Hi Miquel,
> 
> Miquel Raynal <miquel.raynal@bootlin.com> writes:
> 
>> On Wed, 27 Jun 2018 16:33:43 -0700, Kevin Hilman <khilman@baylibre.com>
>> wrote:
>>
>>> Hi Boris,
>>>
>>> Boris Brezillon <boris.brezillon@bootlin.com> writes:
>>>
>>>> Hi Yixun,
>>>>
>>>> On Wed, 13 Jun 2018 16:13:14 +0000
>>>> Yixun Lan <yixun.lan@amlogic.com> wrote:
>>>>  
>>>>> From: Liang Yang <liang.yang@amlogic.com>
>>>>>
>>>>> Add initial support for the Amlogic NAND flash controller which found
>>>>> in the Meson-GXBB/GXL/AXG SoCs.
>>>>>
>>>>> Singed-off-by: Liang Yang <liang.yang@amlogic.com>
>>>>> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>>>>> ---
>>>>>  drivers/mtd/nand/raw/Kconfig      |    8 +
>>>>>  drivers/mtd/nand/raw/Makefile     |    3 +
>>>>>  drivers/mtd/nand/raw/meson_nand.c | 1422 +++++++++++++++++++++++++++++
>>>>>  3 files changed, 1433 insertions(+)
>>>>>  create mode 100644 drivers/mtd/nand/raw/meson_nand.c  
>>>>
>>>> Can you run checkpatch.pl --strict and fix the coding style issues?
>>>>  
>>>>>
>>>>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>>>>> index 19a2b283fbbe..b3c17a3ca8f4 100644
>>>>> --- a/drivers/mtd/nand/raw/Kconfig
>>>>> +++ b/drivers/mtd/nand/raw/Kconfig
>>>>> @@ -534,4 +534,12 @@ config MTD_NAND_MTK
>>>>>  	  Enables support for NAND controller on MTK SoCs.
>>>>>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
>>>>>  
>>>>> +config MTD_NAND_MESON
>>>>> +	tristate "Support for NAND flash controller on Amlogic's Meson SoCs"
>>>>> +	depends on ARCH_MESON || COMPILE_TEST
>>>>> +	select COMMON_CLK_REGMAP_MESON
>>>>> +	select MFD_SYSCON
>>>>> +	help
>>>>> +	  Enables support for NAND controller on Amlogic's Meson SoCs.
>>>>> +
>>>>>  endif # MTD_NAND
>>>>> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
>>>>> index 165b7ef9e9a1..cdf6162f38c3 100644
>>>>> --- a/drivers/mtd/nand/raw/Makefile
>>>>> +++ b/drivers/mtd/nand/raw/Makefile
>>>>> @@ -1,5 +1,7 @@
>>>>>  # SPDX-License-Identifier: GPL-2.0
>>>>>  
>>>>> +ccflags-$(CONFIG_MTD_NAND_MESON) += -I$(srctree)/drivers/clk/meson  
>>>>
>>>> Please don't do that. If you need to expose common regs, put them
>>>> in include/linux/soc/meson/. I'm also not sure why you need to access
>>>> the clk regs directly. Why can't you expose the MMC/NAND clk as a clk
>>>> provider whose driver would be placed in drivers/clk and which would use
>>>> the mmc syscon. This way the same clk driver could be used for both
>>>> MMC and NAND clk indifferently, and the NAND driver would be much
>>>> simpler.  
>>>
>>> [...]
>>>
>>>>> +
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>>> +static const char * sd_emmc_ext_clk0_parent_names[MUX_CLK_NUM_PARENTS];
>>>>> +
>>>>> +static struct clk_regmap sd_emmc_c_ext_clk0_sel = {
>>>>> +	.data = &(struct clk_regmap_mux_data){
>>>>> +		.offset = SD_EMMC_CLOCK,
>>>>> +		.mask = 0x3,
>>>>> +		.shift = 6,
>>>>> +	},
>>>>> +	.hw.init = &(struct clk_init_data) {
>>>>> +		.name = "sd_emmc_c_nand_clk_mux",
>>>>> +		.ops = &clk_regmap_mux_ops,
>>>>> +		.parent_names = sd_emmc_ext_clk0_parent_names,
>>>>> +		.num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
>>>>> +		.flags = CLK_SET_RATE_PARENT,
>>>>> +	},
>>>>> +};
>>>>> +
>>>>> +static struct clk_regmap sd_emmc_c_ext_clk0_div = {
>>>>> +	.data = &(struct clk_regmap_div_data){
>>>>> +		.offset = SD_EMMC_CLOCK,
>>>>> +		.shift = 0,
>>>>> +		.width = 6,
>>>>> +		.flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
>>>>> +	},
>>>>> +	.hw.init = &(struct clk_init_data) {
>>>>> +		.name = "sd_emmc_c_nand_clk_div",
>>>>> +		.ops = &clk_regmap_divider_ops,
>>>>> +		.parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
>>>>> +		.num_parents = 1,
>>>>> +		.flags = CLK_SET_RATE_PARENT,
>>>>> +	},
>>>>> +};
>>>>> +
>>>>> +static int meson_nfc_clk_init(struct meson_nfc *nfc)
>>>>> +{
>>>>> +	struct clk_regmap *mux = &sd_emmc_c_ext_clk0_sel;
>>>>> +	struct clk_regmap *div = &sd_emmc_c_ext_clk0_div;
>>>>> +	struct clk *clk;
>>>>> +	int i, ret;
>>>>> +
>>>>> +	/* request core clock */
>>>>> +	nfc->core_clk = devm_clk_get(nfc->dev, "core");
>>>>> +	if (IS_ERR(nfc->core_clk)) {
>>>>> +		dev_err(nfc->dev, "failed to get core clk\n");
>>>>> +		return PTR_ERR(nfc->core_clk);
>>>>> +	}
>>>>> +
>>>>> +	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
>>>>> +	regmap_update_bits(nfc->reg_clk, 0,
>>>>> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK,
>>>>> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK);
>>>>> +
>>>>> +	/* get the mux parents */
>>>>> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
>>>>> +		char name[16];
>>>>> +
>>>>> +		snprintf(name, sizeof(name), "clkin%d", i);
>>>>> +		clk = devm_clk_get(nfc->dev, name);
>>>>> +		if (IS_ERR(clk)) {
>>>>> +			if (clk != ERR_PTR(-EPROBE_DEFER))
>>>>> +				dev_err(nfc->dev, "Missing clock %s\n", name);
>>>>> +			return PTR_ERR(clk);
>>>>> +		}
>>>>> +
>>>>> +		sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
>>>>> +	}
>>>>> +
>>>>> +	mux->map = nfc->reg_clk;
>>>>> +	clk = devm_clk_register(nfc->dev, &mux->hw);
>>>>> +	if (WARN_ON(IS_ERR(clk)))
>>>>> +		return PTR_ERR(clk);
>>>>> +
>>>>> +	div->map = nfc->reg_clk;
>>>>> +	nfc->device_clk = devm_clk_register(nfc->dev, &div->hw);
>>>>> +	if (WARN_ON(IS_ERR(nfc->device_clk)))
>>>>> +		return PTR_ERR(nfc->device_clk);
>>>>> +
>>>>> +	ret = clk_prepare_enable(nfc->core_clk);
>>>>> +	if (ret) {
>>>>> +		dev_err(nfc->dev, "failed to enable core clk\n");
>>>>> +		return ret;
>>>>> +	}
>>>>> +
>>>>> +	ret = clk_prepare_enable(nfc->device_clk);
>>>>> +	if (ret) {
>>>>> +		dev_err(nfc->dev, "failed to enable device clk\n");
>>>>> +		clk_disable_unprepare(nfc->core_clk);
>>>>> +		return ret;
>>>>> +	}
>>>>> +
>>>>> +	return 0;
>>>>> +}  
>>>>
>>>>
>>>> As said above, I don't like having a clk driver here, especially since
>>>> the registers you're accessing are not part of the NAND controller
>>>> registers. Please try to create a driver in drivers/clk/ for that.  
>>>
>>> We went back and forth on this one on some off-list reviews.
>>>
>>> Had we known that the NAND controller was (re)using the clock registers
>>> internal to the MMC IP block from the beginning, we would have written a
>>> clock provider in drivers/clk for this, and shared it.
>>>
>>> However, when I wrote the MMC driver[1] (already upstream) along with
>>> the bindings[2], we did not fathom that the internal mux and divider
>>> would be "borrowed" by another device. :(
>>>
>>> We only recently found out that the NAND controller "borrows" one of the
>>> MMC clocks, whose registers are inside the MMC range.  Taking the clock
>>> out of the MMC driver and into its own clock-provider implies redoing
>>> the MMC driver, as well as its bindings, which we wanted to avoid
>>> (especially the binding changes.)
>>>
>>> We (I can take the blame) decided that since the MMC and NAND are
>>> mutually exclusive (they also share pins), that allowing NAND to reuse
>>> the MMC range would be a good compromise.  The DT still accurately
>>> describes the hardware, but we don't have to throw a large wrench into
>>> the DT bindings just for a newly discovered shared clock.
>>>
>>> I agree, it's not the prettiest thing, but when we cannot know the full
>>> details of the hardware when we start, sometimes we end up in a bit of a
>>> mess that requires some compromise.
>>
>> I totally understand your situation but as MMC and NAND are mutually
>> exclusive, how is this a problem to have a dedicated clock driver used
>> only by the NAND controller (as maybe a first step)? I mean, if you
>> don't change the MMC bindings, then the MMC driver will still use its
>> own 'local' clock driver, right?
> 
> Yeah, I think you're right.  That would work too.
> 
>> I don't know if you can have two nodes reserving the same address
>> range though.
> 
> You can, but it's a race who gets to claim the region.
> 
> You'd have to have the new clock-controler disabled by default, and have
> any boards that use the NAND disable the MMC and enable the clock
> controller node.
> 
> But I think that should work.
> 
> Yixun, can you give this approach a try?
Yes, It actually works here, I'll send out the clock patches later for
review.

Thanks everyone for the suggestion
> 
> Kevin
> 
> .
>
Yixun Lan July 18, 2018, 9:38 a.m. | #9
Hi Roris

thanks for all your suggestions!

It actually takes us some time to digest all your comments ;-)
and get back to you on these questions.


On 06/25/18 03:38, Boris Brezillon wrote:
> 
> 
> Hi Yixun,
> 
> On Wed, 13 Jun 2018 16:13:14 +0000
> Yixun Lan <yixun.lan@amlogic.com> wrote:
> 
>> From: Liang Yang <liang.yang@amlogic.com>
>>
>> Add initial support for the Amlogic NAND flash controller which found
>> in the Meson-GXBB/GXL/AXG SoCs.
>>
>> Singed-off-by: Liang Yang <liang.yang@amlogic.com>
>> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>> ---
>>  drivers/mtd/nand/raw/Kconfig      |    8 +
>>  drivers/mtd/nand/raw/Makefile     |    3 +
>>  drivers/mtd/nand/raw/meson_nand.c | 1422 +++++++++++++++++++++++++++++
>>  3 files changed, 1433 insertions(+)
>>  create mode 100644 drivers/mtd/nand/raw/meson_nand.c
> 
> Can you run checkpatch.pl --strict and fix the coding style issues?
> 
sure, we will be more cautious about this

>>
>> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
>> index 19a2b283fbbe..b3c17a3ca8f4 100644
>> --- a/drivers/mtd/nand/raw/Kconfig
>> +++ b/drivers/mtd/nand/raw/Kconfig
>> @@ -534,4 +534,12 @@ config MTD_NAND_MTK
>>  	  Enables support for NAND controller on MTK SoCs.
>>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
>>  
>> +config MTD_NAND_MESON
>> +	tristate "Support for NAND flash controller on Amlogic's Meson SoCs"
>> +	depends on ARCH_MESON || COMPILE_TEST
>> +	select COMMON_CLK_REGMAP_MESON
>> +	select MFD_SYSCON
>> +	help
>> +	  Enables support for NAND controller on Amlogic's Meson SoCs.
>> +
>>  endif # MTD_NAND
>> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
>> index 165b7ef9e9a1..cdf6162f38c3 100644
>> --- a/drivers/mtd/nand/raw/Makefile
>> +++ b/drivers/mtd/nand/raw/Makefile
>> @@ -1,5 +1,7 @@
>>  # SPDX-License-Identifier: GPL-2.0
>>  
>> +ccflags-$(CONFIG_MTD_NAND_MESON) += -I$(srctree)/drivers/clk/meson
> 
> Please don't do that. If you need to expose common regs, put them
> in include/linux/soc/meson/. I'm also not sure why you need to access
> the clk regs directly. Why can't you expose the MMC/NAND clk as a clk
> provider whose driver would be placed in drivers/clk and which would use
> the mmc syscon. This way the same clk driver could be used for both
> MMC and NAND clk indifferently, and the NAND driver would be much
> simpler.
> 

this is already addressed in another thread, as we will model it as a
standard clock driver.

so this cflags can be dropped.

>> +
>>  obj-$(CONFIG_MTD_NAND)			+= nand.o
>>  obj-$(CONFIG_MTD_NAND_ECC)		+= nand_ecc.o
>>  obj-$(CONFIG_MTD_NAND_BCH)		+= nand_bch.o
>> @@ -56,6 +58,7 @@ obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
>>  obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
>>  obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
>>  obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
>> +obj-$(CONFIG_MTD_NAND_MESON)		+= meson_nand.o
>>  
>>  nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
>>  nand-objs += nand_amd.o
>> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
>> new file mode 100644
>> index 000000000000..28abc3684772
>> --- /dev/null
>> +++ b/drivers/mtd/nand/raw/meson_nand.c
>> @@ -0,0 +1,1422 @@
>> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
>> +/*
>> + * Amlogic Meson Nand Flash Controller Driver
>> + *
>> + * Copyright (c) 2018 Amlogic, inc.
>> + * Author: Liang Yang <liang.yang@amlogic.com>
>> + */
>> +
>> +#include <linux/platform_device.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/clk.h>
>> +#include <linux/mtd/rawnand.h>
>> +#include <linux/mtd/mtd.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/regmap.h>
>> +#include <linux/module.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include "clk-regmap.h"
>> +
>> +#define NFC_REG_CMD		0x00
>> +#define NFC_REG_CFG		0x04
>> +#define NFC_REG_DADR		0x08
>> +#define NFC_REG_IADR		0x0c
>> +#define NFC_REG_BUF		0x10
>> +#define NFC_REG_INFO		0x14
>> +#define NFC_REG_DC		0x18
>> +#define NFC_REG_ADR		0x1c
>> +#define NFC_REG_DL		0x20
>> +#define NFC_REG_DH		0x24
>> +#define NFC_REG_CADR		0x28
>> +#define NFC_REG_SADR		0x2c
>> +#define NFC_REG_PINS		0x30
>> +#define NFC_REG_VER		0x38
>> +
> 
> Can you put the reg offsets next to their field definitions?
> 
actually, we would prefer to put all the CMD definition below the reg
offset, so it will better reflect what's it belong to.


>> +
>> +#define NFC_CMD_DRD		(0x8 << 14)
>> +#define NFC_CMD_IDLE		(0xc << 14)
>> +#define NFC_CMD_DWR		(0x4 << 14)
>> +#define NFC_CMD_CLE		(0x5 << 14)
>> +#define NFC_CMD_ALE		(0x6 << 14)
>> +#define NFC_CMD_ADL		((0 << 16) | (3 << 20))
>> +#define NFC_CMD_ADH		((1 << 16) | (3 << 20))
>> +#define NFC_CMD_AIL		((2 << 16) | (3 << 20))
>> +#define NFC_CMD_AIH		((3 << 16) | (3 << 20))
>> +#define NFC_CMD_SEED		((8 << 16) | (3 << 20))
>> +#define NFC_CMD_M2N		((0 << 17) | (2 << 20))
>> +#define NFC_CMD_N2M		((1 << 17) | (2 << 20))
>> +#define NFC_CMD_RB		(1 << 20)
>> +#define NFC_CMD_IO6		((0xb << 10) | (1 << 18))
>> +
>> +#define NFC_RB_USED		(1 << 23)
>> +#define NFC_LARGE_PAGE		(1 << 22)
>> +#define NFC_RW_OPS		(2 << 20)
>> +
>> +#define NAND_TWB_TIME_CYCLE	10
>> +
>> +#define CMDRWGEN(cmd_dir, ran, bch, short_mode, page_size, pages)	\
>> +	(								\
>> +		(cmd_dir)			|			\
>> +		((ran) << 19)			|			\
>> +		((bch) << 14)			| 			\
>> +		((short_mode) << 13)		|			\
>> +		(((page_size) & 0x7f) << 6)	|			\
>> +		((pages) & 0x3f)					\
>> +	)
>> +
>> +#define GENCMDDADDRL(adl, addr)		((adl) | ((addr) & 0xffff))
>> +#define GENCMDDADDRH(adh, addr)		((adh) | (((addr) >> 16) & 0xffff))
>> +#define GENCMDIADDRL(ail, addr)		((ail) | ((addr) & 0xffff))
>> +#define GENCMDIADDRH(aih, addr)		((aih) | (((addr) >> 16) & 0xffff))
>> +
>> +#define RB_STA(x)		(1 << (26 + x))
>> +
>> +#define ECC_CHECK_RETURN_FF	(-1)
>> +
>> +#define NAND_CE0		(0xe << 10)
>> +#define NAND_CE1		(0xd << 10)
>> +
>> +#define DMA_BUSY_TIMEOUT	0x100000
>> +
>> +#define MAX_CE_NUM		2
>> +#define RAN_ENABLE		1
>> +
>> +#define SD_EMMC_CLOCK 		0x00
>> +#define CLK_ALWAYS_ON		BIT(28)
>> +#define CLK_SELECT_NAND		BIT(31)
>> +#define CLK_DIV_MASK		GENMASK(5, 0)
>> +#define CLK_SRC_MASK		GENMASK(7, 6)
>> +
>> +#define NFC_CLK_CYCLE		6
>> +
>> +/* nand flash controller delay 3 ns */
>> +#define NFC_DEFAULT_DELAY 3000
>> +
>> +#define MAX_ECC_INDEX	10
>> +
>> +#define MUX_CLK_NUM_PARENTS 2
>> +
>> +struct meson_nfc_info_format {
>> +	u16 info_bytes;
>> +	u8 zero_cnt; /* bit0~5 is valid */
>> +	struct ecc_sta {
>> +		u8 eccerr_cnt : 6;
>> +		u8 notused : 1;
>> +		u8 completed : 1;
>> +	} ecc;
>> +	u32 reserved;
>> +};
>> +
>> +#define	PER_INFO_BYTE	(sizeof(struct meson_nfc_info_format))
>> +
>> +struct meson_nfc_nand_chip {
>> +	struct list_head node;
>> +	struct nand_chip nand;
>> +	/*
>> +	 * Then NAND controller support two oob modes:
>> +	 *  a) 2 user bytes with each ecc page;
>> +	 *  b) 16 user bytes with 1st ecc page and zero user byte
>> +	 *      with the other ecc pages.
>> +	 * when using as mtd mode, the driver prefer to use 2 user bytes mode.
> 
> Why not using this mode unconditionally? What's the point of
> maintaining 2 different page layout if only one is used?
> 

after consideration, we will just stick to mode a)

>> +	 */
>> +	int user_mode;
>> +	int rand_mode; /* 0: disable scramble, 1: enable scramble */
>> +	int bch_mode;
>> +	int cs;
>> +
>> +	u8 *data_buf;
>> +	u8 *info_buf;
>> +};
>> +
>> +/*
>> + * While booting from NAND, a page0 data is needed to tell ROM boot code
>> + * to read SPL image, and the ROM boot code need to know which ecc mode
>> + * is selected and whether scramble is enabled or not, and so on.
>> + *
>> + * So when updating SPL image, the driver need to store these informations
>> + * into the page0, and SPL image will be loadded into next page - the page1.
> 
> Clearly not the kind of information that belongs in the NAND controller
> driver. We had the same problem on sunxi platforms where the first few
> blocks are written with a different ECC/scrambler setup (the
> ROM code only supports a pre-defined set of ECC/scrambler configs that
> it tries until it finds one that works).
> 
> What we did to solve that is write the SPL partition in raw mode (ECC
> and scrambler disabled) with an image that already contains the ECC
> bytes has the data appropriately scrambled (for the record, we use the
> sunxi-spl-image-builder [1] tool to generate this raw image).
> 

will drop this as we also have tools ready to generate the raw image.
thanks for suggesting.

>> + */
>> +struct meson_nand_setup {
>> +	u32 d32;
>> +	u16 id;
>> +	u16 max;
>> +};
>> +
>> +struct meson_nand_page0 {
>> +	struct meson_nand_setup nand_setup;
>> +	unsigned char page_list[16];
>> +	unsigned short reserved[32];
>> +};
>> +
>> +struct meson_nand_ecc {
>> +	int bch;
>> +	int strength;
>> +	int parity;
>> +};
>> +
>> +struct meson_nfc_data {
>> +	struct meson_nand_ecc *ecc;
>> +	int ecc_num;
>> +	int bch_mode;
>> +	int short_bch;
>> +};
>> +
>> +struct meson_nfc_param {
>> +	int chip_select;
>> +	int rb_select;
>> +
>> +	int page_size;
>> +	int oob_size;
>> +	int ecc_size;
>> +	int ecc_bytes;
>> +
>> +	int rand_mode;
>> +	int oob_mode;
>> +	int bch_mode;
>> +	int ecc_step;
>> +
>> +	int ecc_max;
>> +};
> 
> Looks like most of these information are tied to the NAND chip and not
> the NAND controller. They should probably be moved to
> meson_nfc_nand_chip.
> 
sure, we fix it

>> +
>> +struct meson_nfc {
>> +	struct nand_hw_control controller;
>> +	struct clk *core_clk;
>> +	struct clk *device_clk;
>> +
>> +	struct device *dev;
>> +	void __iomem *reg_base;
>> +	struct regmap *reg_clk;
>> +
>> +	struct completion completion;
>> +	struct list_head chips;
>> +	struct meson_nfc_data *data;
>> +	struct meson_nfc_param param;
>> +	struct meson_nand_page0 *page0;
>> +
>> +	u8 *data_buf;
>> +	u8 *info_buf;
>> +};
>> +
>> +enum {
>> +	NFC_ECC_NONE	= 0,
>> +	NFC_ECC_BCH8,		/* bch8 with ecc page size of 512B */
>> +	NFC_ECC_BCH8_1K,	/* bch8 with ecc page size of 1024B */
>> +	NFC_ECC_BCH24_1K,
>> +	NFC_ECC_BCH30_1K,
>> +	NFC_ECC_BCH40_1K,
>> +	NFC_ECC_BCH50_1K,
>> +	NFC_ECC_BCH60_1K,
>> +
>> +	/*
>> +	 * Short mode is special only for page 0 when inplement booting
>> +	 * from nand, which means a small size(384 bit / 8 = 48 Byte) of
>> +	 * ecc page is used with a fixed ecc mode. rom code will use short mode
>> +	 * to read page0 for getting nand parameters such as ecc, scramber, etc.
>> +	 *
>> +	 * Example, in GXL SoC, the first page adopt the short mode with
>> +	 * 60bit ecc, while in AXG SoC, it adopt short mode with 8bit ecc.
>> +	 */
>> +	NFC_ECC_BCH_SHORT,
> 
> Let's see if we can avoid supporting this mode. I'm pretty sure you
> have all the information you need to generate ECC bytes and scramble
> data in SW. Then, all you'll need from the NAND controller driver is a
> way to write thing in raw mode, which I'll ask you to support
> anyway ;-).
> 

sure, as mentioned above, we have all the information known and tools to
generate image which can be written in raw mode.

>> +};
>> +
>> +enum {
>> +	NFC_USER2_OOB_BYTES		= 2,
>> +	NFC_USER16_OOB_BYTES		= 16,
>> +};
>> +
>> +#define MESON_ECC_DATA(b, s, p)				\
>> +	{ .bch = (b),	.strength = (s),	.parity = (p) }
>> +
>> +struct meson_nand_ecc meson_gxl_ecc[] = {
>> +	MESON_ECC_DATA(NFC_ECC_NONE, 0, 0),
>> +	MESON_ECC_DATA(NFC_ECC_BCH8, 8, 14),
>> +	MESON_ECC_DATA(NFC_ECC_BCH8_1K, 8, 14),
>> +	MESON_ECC_DATA(NFC_ECC_BCH24_1K, 24, 42),
>> +	MESON_ECC_DATA(NFC_ECC_BCH30_1K, 30, 54),
>> +	MESON_ECC_DATA(NFC_ECC_BCH40_1K, 40, 70),
>> +	MESON_ECC_DATA(NFC_ECC_BCH50_1K, 50, 88),
>> +	MESON_ECC_DATA(NFC_ECC_BCH60_1K, 60, 106),
>> +	MESON_ECC_DATA(NFC_ECC_BCH_SHORT, 0xff, 0xff),
>> +};
>> +
>> +struct meson_nand_ecc meson_axg_ecc[] = {
>> +	MESON_ECC_DATA(NFC_ECC_NONE, 0, 0),
>> +	MESON_ECC_DATA(NFC_ECC_BCH8, 8, 14),
>> +	MESON_ECC_DATA(NFC_ECC_BCH8_1K, 8, 14),
>> +	MESON_ECC_DATA(NFC_ECC_BCH_SHORT, 0xff, 0xff),
>> +};
>> +
>> +static inline struct meson_nfc_nand_chip *to_meson_nand(struct nand_chip *nand)
>> +{
>> +	return container_of(nand, struct meson_nfc_nand_chip, nand);
>> +}
>> +
>> +static int meson_nfc_page0_gen(struct meson_nfc *nfc)
>> +{
>> +	u32 cmd;
>> +
>> +	nfc->page0 = devm_kzalloc(nfc->dev,
>> +		sizeof(struct meson_nand_page0), GFP_KERNEL);
>> +	if(!nfc->page0)
>> +		return -ENOMEM;
>> +
>> +	cmd = CMDRWGEN(NFC_CMD_N2M, nfc->param.rand_mode,
>> +		nfc->param.bch_mode, 0,
>> +		nfc->param.ecc_size >> 3,
>> +		nfc->param.ecc_step);
>> +	cmd |= NFC_RB_USED | NFC_LARGE_PAGE | NFC_RW_OPS;
>> +	nfc->page0->nand_setup.d32 = cmd;
>> +
>> +	return 0;
>> +}
>> +
>> +static void meson_nfc_select_chip(struct mtd_info *mtd, int chip)
>> +{
>> +	struct nand_chip *nand = mtd_to_nand(mtd);
>> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
>> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
>> +
>> +	if (chip != meson_chip->cs)
> 
> I know it's not clear at all, but chip is not encoding the NAND
> controller CS id, but the NAND chip CS id, which can be != 0 for
> multi-die chips.
> 
> To extract the NAND controller CS id, you'll have to parse the NAND
> chip node reg prop, and store the information somewhere in
> meson_nfc_nand_chip. Go check the sunxi if you want an example.
> 
ok, we will fix this

>> +		return;
>> +
>> +	nfc->param.chip_select = chip ? NAND_CE1 : NAND_CE0;
>> +	nfc->param.rb_select = chip ? NAND_CE1 : NAND_CE0;
>> +	nfc->param.oob_mode =
>> +		(meson_chip->user_mode == NFC_USER2_OOB_BYTES) ? 0 : 1;
>> +	nfc->param.rand_mode = meson_chip->rand_mode;
>> +	nfc->param.bch_mode = meson_chip->bch_mode;
>> +
>> +	nfc->param.ecc_step = mtd->writesize / nand->ecc.size;
>> +	nfc->param.ecc_size = nand->ecc.size;
>> +	nfc->param.ecc_bytes =  nand->ecc.bytes;
>> +	nfc->param.page_size = mtd->writesize;
>> +	nfc->param.oob_size =  mtd->oobsize;
>> +	nfc->param.ecc_max = nand->ecc.strength;
>> +
>> +	nfc->data_buf = meson_chip->data_buf;
>> +	nfc->info_buf = meson_chip->info_buf;
>> +}
>> +
>> +static inline void meson_nfc_cmd_idle(struct meson_nfc *nfc, u32 time)
>> +{
>> +	writel(nfc->param.chip_select | NFC_CMD_IDLE | (time & 0x3ff),
>> +			nfc->reg_base + NFC_REG_CMD);
>> +}
>> +
>> +static void meson_nfc_cmd_ctrl(struct mtd_info *mtd,
>> +					int cmd, unsigned int ctrl)
> 
> ->cmd_ctrl() has recently been deprecated in favor of ->exec_op(). You
> can have a look at the marvell, v610 or fsmc drivers if you want to
> have an idea of how ->exec_op() should be implemented. Miquel and I are
> also here to help if you have any questions.
> 

follow your suggestion, we have implemented the exec_op() interface,
we'd really appreciate if you can help to review this ..

>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
>> +
>> +	if (cmd == NAND_CMD_NONE)
>> +		return;
>> +
>> +	cmd = nfc->param.chip_select | (cmd & 0xff);
>> +	cmd |= (ctrl & NAND_CLE) ? NFC_CMD_CLE : NFC_CMD_ALE;
>> +
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +}
>> +
>> +static inline void meson_nfc_cmd_seed(struct meson_nfc *nfc, u32 seed)
>> +{
>> +	writel(NFC_CMD_SEED | (0xc2 + (seed & 0x7fff)),
>> +			nfc->reg_base + NFC_REG_CMD);
>> +}
>> +
>> +static void meson_nfc_cmd_m2n(struct meson_nfc *nfc, int raw)
> 
> n2m -> nand2mem ?
> 
yes, it is

>> +{
>> +	u32 cmd, pagesize, pages, shortm = 0;
>> +	int bch = nfc->param.bch_mode;
>> +	int len = nfc->param.page_size;
>> +
>> +	pagesize = nfc->param.ecc_size;
>> +
>> +	if (unlikely(raw)) {
> 
> I think you'll have plenty of things to optimize before this branch
> prediction becomes the bottleneck ;-). Please don't use
> unlikely()/likely() statements unless you have numbers showing a
> noticeable improvement.
> 
thank you for the advice, it's not really necessary, will drop them


>> +		bch = NAND_ECC_NONE;
>> +		len = nfc->param.page_size + nfc->param.oob_size;
>> +		cmd = NFC_CMD_M2N |
>> +			(len & 0x3fff) | (nfc->param.rand_mode << 19);
>> +		writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +		return;
>> +	}
>> +
>> +	if (unlikely(bch == NFC_ECC_BCH_SHORT)) {
>> +		bch = nfc->data->short_bch;
>> +		pagesize = 384 >> 3;
>> +		pages = len / nfc->param.ecc_size;
>> +		memcpy(nfc->data_buf,
>> +			nfc->page0, sizeof(struct meson_nand_page0));
>> +		shortm = 1;
>> +	} else
>> +		pages = len / nfc->param.ecc_size;
>> +
>> +	cmd = CMDRWGEN(NFC_CMD_M2N,
>> +		nfc->param.rand_mode, bch, shortm, pagesize, pages);
>> +
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +}
>> +
>> +static void meson_nfc_cmd_n2m(struct meson_nfc *nfc, int raw)
>> +{
>> +	u32 cmd, pagesize, pages, shortm = 0;
>> +	int bch = nfc->param.bch_mode;
>> +	int len = nfc->param.page_size;
>> +
>> +	pagesize = nfc->param.ecc_size;
>> +
>> +	if (unlikely(raw)) {
>> +		bch = NAND_ECC_NONE;
>> +		len = nfc->param.page_size + nfc->param.oob_size;
>> +		cmd = (len & 0x3fff) | (nfc->param.rand_mode << 19) |
>> +			NFC_CMD_N2M;
>> +		writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +		return;
>> +	}
>> +
>> +	if (unlikely(bch == NFC_ECC_BCH_SHORT)) {
>> +		bch = nfc->data->short_bch;
>> +		pagesize = 384 >> 3;
>> +		pages = len / nfc->param.ecc_size;
>> +		shortm = 1;
>> +	} else
>> +		pages = len / nfc->param.ecc_size;
>> +
>> +	cmd = CMDRWGEN(NFC_CMD_N2M,
>> +		nfc->param.rand_mode, bch, shortm, pagesize, pages);
>> +
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +}
> 
> Looks like there's a lot in common in meson_nfc_cmd_m2n() and
> meson_nfc_cmd_n2m(). Wouldn't it be better to have a single function and
> pass the direction.
> 
sure, good idea, will construct a meson_nfc_cmd_access() helper to do this

>> +
>> +static int meson_nfc_wait_cmd_finish(struct meson_nfc *nfc,
>> +					unsigned int timeout_ms)
>> +{
>> +	u32 cmd_size = 0;
>> +	int ret;
>> +
>> +	/* wait cmd fifo is empty */
>> +	ret = readl_poll_timeout(nfc->reg_base + NFC_REG_CMD,
>> +				cmd_size,
>> +				!((cmd_size >> 22) & 0x1f),
>> +				10, timeout_ms * 1000);
>> +	if (ret)
>> +		dev_err(nfc->dev, "wait for empty cmd FIFO time out\n");
>> +
>> +	return ret;
>> +}
>> +
>> +static int meson_nfc_wait_dma_finish(struct meson_nfc *nfc)
>> +{
>> +	meson_nfc_cmd_idle(nfc, 0);
>> +	meson_nfc_cmd_idle(nfc, 0);
> 
> Two calls to cmd_idle(), is this expected or a copy&paste error? If
> that's expected it definitely deserves a comment explaining why?
> 

yes, it is intentional

we will put these comments into the function.
	/*
         * The Nand flash controller is designed as two stages pipleline -
         *  a) fetch and b) excute.
         * So, there might be cases when the driver see command queue is
empty,
         * but the Nand flash controller still has two commands buffered,
         * one is fetched into NFC request queue (ready to run), and another
         * is actively executing.
         */


>> +
>> +	return meson_nfc_wait_cmd_finish(nfc, DMA_BUSY_TIMEOUT);
>> +}
>> +
>> +static inline struct meson_nfc_info_format *nfc_info_ptr(struct meson_nfc *nfc,
>> +	int index)
>> +{
>> +	return (struct meson_nfc_info_format *) &nfc->info_buf[index * 8];
>> +}
>> +
>> +static u8 *meson_nfc_oob_ptr(struct meson_nfc *nfc, int i)
>> +{
>> +	int x, len;
>> +	int ecc_bytes = nfc->param.ecc_bytes, temp = nfc->param.ecc_size;
>> +
>> +	x = i ? 16 : 0;
>> +	len = (nfc->param.oob_mode) ? (temp * (i + 1) + ecc_bytes * i + x) :
>> +				(temp * (i + 1) + (ecc_bytes + 2) * i);
>> +
>> +	return nfc->data_buf + len;
>> +}
>> +
>> +static u8 *meson_nfc_data_ptr(struct meson_nfc *nfc, int i)
>> +{
>> +	int len, x;
>> +	int temp = nfc->param.ecc_size + nfc->param.ecc_bytes;
>> +
>> +	x = i ? 16 : 0;
>> +	len = nfc->param.oob_mode ? (temp * i + x) : (temp + 2) * i;
>> +
>> +	return nfc->data_buf + len;
>> +}
>> +
>> +static void meson_nfc_prase_data_oob(struct meson_nfc *nfc, u8 *buf, u8 *oob)
>> +{
>> +	int i, oob_len = 0;
>> +	u8 *dsrc, *osrc;
>> +
>> +	for (i = 0; i < nfc->param.ecc_step; i++) {
>> +		if (buf) {
>> +			dsrc = meson_nfc_data_ptr(nfc, i);
>> +			memcpy(buf, dsrc, nfc->param.ecc_size);
>> +			buf += nfc->param.ecc_size;
>> +		}
>> +
>> +		if (nfc->param.oob_mode)
>> +			oob_len = (i) ? nfc->param.ecc_bytes :
>> +						nfc->param.ecc_bytes + 16;
>> +		else
>> +			oob_len = nfc->param.ecc_bytes + 2;
>> +
>> +		osrc = meson_nfc_oob_ptr(nfc, i);
>> +		memcpy(oob, osrc, oob_len);
>> +		oob += oob_len;
>> +	}
>> +}
>> +
>> +static void meson_nfc_format_data_oob(struct meson_nfc *nfc,
>> +						const u8 *buf, u8 *oob)
>> +{
>> +	int i, oob_len = 0;
>> +	u8 *dsrc, *osrc;
>> +
>> +	for (i = 0; i < nfc->param.ecc_step; i++) {
>> +		if (buf) {
>> +			dsrc = meson_nfc_data_ptr(nfc, i);
>> +			memcpy(dsrc, buf, nfc->param.ecc_size);
>> +			buf += nfc->param.ecc_size;
>> +		}
>> +
>> +		if (nfc->param.oob_mode)
>> +			oob_len = i ? nfc->param.ecc_bytes :
>> +						nfc->param.ecc_bytes + 16;
>> +		else
>> +			oob_len = nfc->param.ecc_bytes + 2;
>> +
>> +		osrc = meson_nfc_oob_ptr(nfc, i);
>> +		memcpy(osrc, oob, oob_len);
>> +		oob += oob_len;
>> +	}
>> +}
>> +
>> +static int meson_nfc_queue_rb(struct meson_nfc *nfc)
>> +{
>> +	u32 cmd, cfg;
>> +	int ret = 0;
>> +
>> +	init_completion(&nfc->completion);
>> +
>> +	cfg = readl(nfc->reg_base + NFC_REG_CFG);
>> +	cfg |= (1 << 21);
>> +	writel(cfg, nfc->reg_base + NFC_REG_CFG);
>> +
>> +	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
>> +	cmd = nfc->param.chip_select | NFC_CMD_CLE | (NAND_CMD_STATUS & 0xff);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
>> +
>> +	cmd = NFC_CMD_RB | NFC_CMD_IO6 | (1 << 16) | (0x18 & 0x1f);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +	meson_nfc_cmd_idle(nfc, 2);
>> +
>> +	ret = wait_for_completion_timeout(&nfc->completion,
>> +					msecs_to_jiffies(1000));
>> +	if (ret == 0) {
>> +		dev_err(nfc->dev, "wait nand irq timeout\n");
>> +		ret = -1;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static void meson_nfc_set_user_byte(struct mtd_info *mtd,
>> +					struct nand_chip *chip, u8 *oob_buf)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	struct meson_nfc_info_format *info;
>> +	int i, count;
>> +
>> +	if (nfc->param.oob_mode) {
>> +		memcpy(nfc->info_buf, oob_buf, 16);
>> +		return;
>> +	}
>> +
>> +	for (i = 0, count = 0; i < chip->ecc.steps; i++, count += 2) {
>> +		info = nfc_info_ptr(nfc, i);
>> +		info->info_bytes =
>> +			oob_buf[count] | (oob_buf[count + 1] << 8);
>> +	}
>> +}
>> +
>> +static void meson_nfc_get_user_byte(struct mtd_info *mtd,
>> +					struct nand_chip *chip, u8 *oob_buf)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	struct meson_nfc_info_format *info;
>> +	int i, count;
>> +
>> +	if (nfc->param.oob_mode) {
>> +		memcpy(oob_buf,  nfc->info_buf, 16);
>> +		return;
>> +	}
>> +
>> +	for (i = 0, count = 0; i < chip->ecc.steps; i++, count += 2) {
>> +		info = nfc_info_ptr(nfc, i);
>> +		oob_buf[count] = info->info_bytes & 0xff;
>> +		oob_buf[count + 1] = (info->info_bytes >> 8) & 0xff;
>> +	}
>> +}
>> +
>> +static int meson_nfc_ecc_correct(struct mtd_info *mtd,
>> +						struct nand_chip *chip)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	struct meson_nfc_info_format *info;
>> +	u32 bitflips = 0, i;
>> +	u8 zero_cnt;
>> +
>> +	for (i = 0; i < nfc->param.ecc_step; i++) {
>> +		info = nfc_info_ptr(nfc, i);
>> +		if (info->ecc.eccerr_cnt == 0x3f) {
>> +			zero_cnt = info->zero_cnt & 0x3f;
>> +			if (nfc->param.rand_mode
>> +				&& (zero_cnt < nfc->param.ecc_max))
>> +				return ECC_CHECK_RETURN_FF;
>> +			mtd->ecc_stats.failed++;
>> +			continue;
>> +		}
>> +		mtd->ecc_stats.corrected += info->ecc.eccerr_cnt;
>> +		bitflips = max_t(u32, bitflips, info->ecc.eccerr_cnt);
>> +	}
>> +
>> +	return bitflips;
>> +}
>> +
>> +static inline u8 meson_nfc_read_byte(struct mtd_info *mtd)
>> +{
>> +	struct nand_chip *chip = mtd_to_nand(mtd);
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	u32 cmd;
>> +
>> +	cmd = nfc->param.chip_select | NFC_CMD_DRD | 0;
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +
>> +	meson_nfc_cmd_idle(nfc, 0);
>> +	meson_nfc_cmd_idle(nfc, 0);
>> +
>> +	meson_nfc_wait_cmd_finish(nfc, 1000);
>> +
>> +	return readb(nfc->reg_base + NFC_REG_BUF);
>> +}
>> +
>> +static void meson_nfc_read_buf(struct mtd_info *mtd, u8 *buf, int len)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < len; i++)
>> +		buf[i] = meson_nfc_read_byte(mtd);
>> +}
>> +
>> +static void meson_nfc_write_byte(struct mtd_info *mtd, u8 byte)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
>> +	u32 cmd;
>> +
>> +	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
>> +
>> +	cmd = nfc->param.chip_select | NFC_CMD_DWR | (byte & 0xff);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +
>> +	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
>> +	meson_nfc_cmd_idle(nfc, 0);
>> +
>> +	meson_nfc_wait_cmd_finish(nfc, 1000);
>> +}
>> +
>> +static void meson_nfc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < len; i++)
>> +		meson_nfc_write_byte(mtd, buf[i]);
>> +}
>> +
>> +static int meson_nfc_write_page_sub(struct mtd_info *mtd,
>> +		struct nand_chip *chip, const u8 *buf, int page, int raw)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	dma_addr_t daddr, iaddr;
>> +	u32 cmd;
>> +	int ret;
>> +
>> +	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
>> +
>> +	daddr = dma_map_single(nfc->dev, (void *)nfc->data_buf,
>> +			mtd->writesize + mtd->oobsize, DMA_TO_DEVICE);
>> +	ret = dma_mapping_error(nfc->dev, daddr);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "dma mapping error\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	iaddr = dma_map_single(nfc->dev, (void *)nfc->info_buf,
>> +			nfc->param.ecc_step * PER_INFO_BYTE, DMA_TO_DEVICE);
>> +	ret = dma_mapping_error(nfc->dev, iaddr);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "dma mapping error\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	cmd = GENCMDDADDRL(NFC_CMD_ADL, daddr);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +	cmd = GENCMDDADDRH(NFC_CMD_ADH, daddr);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +
>> +	cmd = GENCMDIADDRL(NFC_CMD_AIL, iaddr);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +	cmd = GENCMDIADDRH(NFC_CMD_AIH, iaddr);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +
>> +	meson_nfc_cmd_seed(nfc, page);
>> +
>> +	meson_nfc_cmd_m2n(nfc, raw);
>> +
>> +	ret = meson_nfc_wait_dma_finish(nfc);
>> +
>> +	dma_unmap_single(nfc->dev, daddr,
>> +			mtd->writesize + mtd->oobsize, DMA_TO_DEVICE);
>> +	dma_unmap_single(nfc->dev, iaddr,
>> +			nfc->param.ecc_step * PER_INFO_BYTE, DMA_TO_DEVICE);
>> +
>> +	return nand_prog_page_end_op(chip);
>> +}
>> +
>> +static int meson_nfc_write_page_raw(struct mtd_info *mtd,
>> +	struct nand_chip *chip, const u8 *buf, int oob_required, int page)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	u8 *oob_buf = chip->oob_poi;
>> +
>> +	meson_nfc_format_data_oob(nfc, buf, oob_buf);
>> +
>> +	return meson_nfc_write_page_sub(mtd, chip, nfc->data_buf, page, 1);
>> +}
>> +
>> +static int meson_nfc_write_page_hwecc(struct mtd_info *mtd,
>> +				    struct nand_chip *chip, const u8 *buf,
>> +				    int oob_required, int page)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	u8 *oob_buf = chip->oob_poi;
>> +
>> +	memcpy(nfc->data_buf, buf, mtd->writesize);
>> +	meson_nfc_set_user_byte(mtd, chip, oob_buf);
>> +
>> +	return meson_nfc_write_page_sub(mtd, chip, nfc->data_buf, page, 0);
>> +}
>> +
>> +static void meson_nfc_check_ecc_pages_valid(struct meson_nfc *nfc, int raw)
>> +{
>> +	struct meson_nfc_info_format *info;
>> +	int neccpages, i;
>> +
>> +	neccpages = raw ? 1 : nfc->param.ecc_step;
>> +
>> +	for (i = 0; i < neccpages; i++) {
>> +		info = nfc_info_ptr(nfc, neccpages - 1);
>> +		if (info->ecc.completed == 0)
>> +			dev_err(nfc->dev, "seems eccpage is invalid\n");
>> +	}
>> +}
>> +
>> +static int meson_nfc_read_page_sub(struct mtd_info *mtd,
>> +	struct nand_chip *chip, const u8 *buf, int page, int raw)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	dma_addr_t daddr, iaddr;
>> +	u32 cmd;
>> +	int ret;
>> +
>> +	nand_read_page_op(chip, page, 0, NULL, 0);
>> +
>> +	daddr = dma_map_single(nfc->dev, nfc->data_buf,
>> +			mtd->writesize + mtd->oobsize, DMA_FROM_DEVICE);
>> +	ret = dma_mapping_error(nfc->dev, daddr);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "dma mapping error\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	iaddr = dma_map_single(nfc->dev, nfc->info_buf,
>> +			nfc->param.ecc_step * PER_INFO_BYTE, DMA_FROM_DEVICE);
>> +	ret = dma_mapping_error(nfc->dev, iaddr);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "dma mapping error\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	cmd = GENCMDDADDRL(NFC_CMD_ADL, daddr);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +	cmd = GENCMDDADDRH(NFC_CMD_ADH, daddr);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +
>> +	cmd = GENCMDIADDRL(NFC_CMD_AIL, iaddr);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +	cmd = GENCMDIADDRH(NFC_CMD_AIH, iaddr);
>> +	writel(cmd, nfc->reg_base + NFC_REG_CMD);
>> +
>> +	meson_nfc_cmd_seed(nfc, page);
>> +
>> +	meson_nfc_cmd_n2m(nfc, raw);
>> +
>> +	ret = meson_nfc_wait_dma_finish(nfc);
>> +
>> +	meson_nfc_queue_rb(nfc);
>> +
>> +	meson_nfc_check_ecc_pages_valid(nfc, raw);
>> +
>> +	dma_unmap_single(nfc->dev, daddr,
>> +			mtd->writesize + mtd->oobsize, DMA_FROM_DEVICE);
>> +	dma_unmap_single(nfc->dev, iaddr,
>> +			nfc->param.ecc_step * PER_INFO_BYTE, DMA_FROM_DEVICE);
>> +
>> +	return ret;
>> +}
>> +
>> +static int meson_nfc_read_page_raw(struct mtd_info *mtd,
>> +	struct nand_chip *chip, u8 *buf, int oob_required, int page)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	u8 *oob_buf = chip->oob_poi;
>> +	int ret;	
>> +
>> +	ret = meson_nfc_read_page_sub(mtd, chip, nfc->data_buf, page, 1);
>> +	if (ret)
>> +		return ret;
>> +
>> +	meson_nfc_prase_data_oob(nfc, buf, oob_buf);
>> +
>> +	return 0;
>> +}
>> +
>> +static int meson_nfc_read_page_hwecc(struct mtd_info *mtd,
>> +	struct nand_chip *chip, u8 *buf, int oob_required, int page)
>> +{
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	u8 *oob_buf = chip->oob_poi;
>> +	int ret;
>> +
>> +	ret = meson_nfc_read_page_sub(mtd, chip, nfc->data_buf, page, 0);
>> +	if (ret)
>> +		return ret;
>> +
>> +	meson_nfc_get_user_byte(mtd, chip, oob_buf);
>> +
>> +	ret = meson_nfc_ecc_correct(mtd, chip);
>> +	if (ret == ECC_CHECK_RETURN_FF) {
>> +		if (buf)
>> +			memset(buf, 0xff, mtd->writesize);
>> +
>> +		memset(oob_buf, 0xff, mtd->oobsize);
>> +		return 0;
>> +	}
>> +	if (buf && (buf != nfc->data_buf))
>> +		memcpy(buf, nfc->data_buf, mtd->writesize);
>> +
>> +	return ret;
>> +}
>> +
>> +static int meson_nfc_read_oob_raw(struct mtd_info *mtd,
>> +				struct nand_chip *chip, int page)
>> +{
>> +	return meson_nfc_read_page_raw(mtd, chip, NULL, 1, page);
>> +}
>> +
>> +static int meson_nfc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
>> +				int page)
>> +{
>> +	return meson_nfc_read_page_hwecc(mtd, chip, NULL, 1, page);
>> +}
>> +
>> +static int meson_ooblayout_ecc(struct mtd_info *mtd, int section,
>> +				  struct mtd_oob_region *oobregion)
>> +{
>> +	struct nand_chip *chip = mtd_to_nand(mtd);
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +	int free_oob;
>> +
>> +	if (section > chip->ecc.steps)
> 
> 	if (section >= chip->ecc.steps)
> 
sure, will fix
>> +		return -ERANGE;
>> +
>> +	free_oob = nfc->param.oob_mode ? 16 : (chip->ecc.steps * 2);
> 
> Hm, are you sure all free OOB bytes are placed at the beginning of the
> OOB buffer? Shouldn't it be section * 2 instead of chip->ecc.steps * 2?
> 
> 	

you're right here, we will fix this

> 
>> +	oobregion->offset = section * chip->ecc.bytes + free_oob;
>> +	oobregion->length = chip->ecc.bytes;
>> +
>> +	return 0;
>> +}
>> +
>> +static int meson_ooblayout_free(struct mtd_info *mtd, int section,
>> +				   struct mtd_oob_region *oobregion)
>> +{
>> +	struct nand_chip *chip = mtd_to_nand(mtd);
>> +	struct meson_nfc *nfc = nand_get_controller_data(chip);
>> +
>> +	if (section > chip->ecc.steps)
> 
> 	if (section >= chip->ecc.steps)
> 
sure, will fix

>> +		return -ERANGE;
>> +
>> +	oobregion->offset = 0;
>> +	oobregion->length = nfc->param.oob_mode ? 16 : (chip->ecc.steps * 2);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct mtd_ooblayout_ops meson_ooblayout_ops = {
>> +	.ecc = meson_ooblayout_ecc,
>> +	.free = meson_ooblayout_free,
>> +};
>> +
>> +static int meson_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
>> +{
>> +	struct nand_chip *nand = mtd_to_nand(mtd);
>> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
>> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
>> +	struct meson_nand_ecc *meson_ecc = nfc->data->ecc;
>> +	int num = nfc->data->ecc_num;
>> +	int nsectors, i, bytes;
>> +
>> +	/* support only ecc hw mode */
>> +	if (nand->ecc.mode != NAND_ECC_HW) {
> 
> Given that you support raw accesses, I'm pretty sure you can support
> ECC_NONE, ECC_SOFT and ECC_ON_DIE with zero effort.
> 

is this a block for this driver to be accepted by upstream?
otherwise we'd like to implement this feature later in separate patch.


>> +		dev_err(dev, "ecc.mode not supported\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (!nand->ecc.size || !nand->ecc.strength) {
>> +		/* use datasheet requirements */
>> +		nand->ecc.strength = nand->ecc_strength_ds;
>> +		nand->ecc.size = nand->ecc_step_ds;
>> +	}
>> +
>> +	if (nand->ecc.options & NAND_ECC_MAXIMIZE) {
>> +		nand->ecc.size = 1024;
>> +		nsectors = mtd->writesize / nand->ecc.size;
>> +
>> +		/* Reserve 2 bytes for each ecc page */
>> +		if (meson_chip->user_mode == NFC_USER2_OOB_BYTES)
>> +			bytes = mtd->oobsize - 2 * nsectors;
>> +		else
>> +			bytes = mtd->oobsize - 16;
>> +
>> +		bytes /= nsectors;
>> +
>> +		/* and bytes has to be even. */
>> +		if (bytes % 2)
>> +			bytes--;
>> +
>> +		nand->ecc.strength = bytes * 8 / fls(8 * nand->ecc.size);
>> +	} else {
>> +		if (nand->ecc.strength > meson_ecc[num - 1].strength) {
>> +			dev_err(dev, "not support ecc strength\n");
>> +			return -EINVAL;
>> +		}
>> +	}
>> +
>> +	for (i = 0; i < num; i++) {
>> +		if ((meson_ecc[i].strength == 0xff)
>> +			|| (nand->ecc.strength < meson_ecc[i].strength))
>> +			break;
>> +	}
>> +
>> +	if (!i) {
>> +		nand->ecc.strength = 0;
>> +	} else {
>> +		nand->ecc.strength = meson_ecc[i - 1].strength;
>> +		nand->ecc.bytes = meson_ecc[i - 1].parity;
>> +	}
>> +
>> +	meson_chip->bch_mode = meson_ecc[i - 1].bch;
>> +
>> +	if (nand->ecc.size != 512 && nand->ecc.size != 1024)
>> +		return -EINVAL;
>> +
>> +	nsectors = mtd->writesize / nand->ecc.size;
>> +	bytes =(meson_chip->user_mode == NFC_USER2_OOB_BYTES) ? nsectors * 2 : 16;
>> +	if (mtd->oobsize < (nand->ecc.bytes * nsectors + bytes))
>> +		return -EINVAL;
> 
> It's probably worth looking at what is being proposed here [2] for the
> ECC config selection logic.
> 

sure, we'd happy to adopt the ECC config helper function, and seems it
is possible ;-)

sounds the proposed ECC config patch is still under review, and we
would like to adjust our code once it's ready (probably we will still
keep this version in patch v2, then address it in v3 later)


>> +
>> +	return 0;
>> +}
>> +
>> +static const char * sd_emmc_ext_clk0_parent_names[MUX_CLK_NUM_PARENTS];
>> +
>> +static struct clk_regmap sd_emmc_c_ext_clk0_sel = {
>> +	.data = &(struct clk_regmap_mux_data){
>> +		.offset = SD_EMMC_CLOCK,
>> +		.mask = 0x3,
>> +		.shift = 6,
>> +	},
>> +	.hw.init = &(struct clk_init_data) {
>> +		.name = "sd_emmc_c_nand_clk_mux",
>> +		.ops = &clk_regmap_mux_ops,
>> +		.parent_names = sd_emmc_ext_clk0_parent_names,
>> +		.num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
>> +		.flags = CLK_SET_RATE_PARENT,
>> +	},
>> +};
>> +
>> +static struct clk_regmap sd_emmc_c_ext_clk0_div = {
>> +	.data = &(struct clk_regmap_div_data){
>> +		.offset = SD_EMMC_CLOCK,
>> +		.shift = 0,
>> +		.width = 6,
>> +		.flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
>> +	},
>> +	.hw.init = &(struct clk_init_data) {
>> +		.name = "sd_emmc_c_nand_clk_div",
>> +		.ops = &clk_regmap_divider_ops,
>> +		.parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
>> +		.num_parents = 1,
>> +		.flags = CLK_SET_RATE_PARENT,
>> +	},
>> +};
>> +
>> +static int meson_nfc_clk_init(struct meson_nfc *nfc)
>> +{
>> +	struct clk_regmap *mux = &sd_emmc_c_ext_clk0_sel;
>> +	struct clk_regmap *div = &sd_emmc_c_ext_clk0_div;
>> +	struct clk *clk;
>> +	int i, ret;
>> +
>> +	/* request core clock */
>> +	nfc->core_clk = devm_clk_get(nfc->dev, "core");
>> +	if (IS_ERR(nfc->core_clk)) {
>> +		dev_err(nfc->dev, "failed to get core clk\n");
>> +		return PTR_ERR(nfc->core_clk);
>> +	}
>> +
>> +	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
>> +	regmap_update_bits(nfc->reg_clk, 0,
>> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK,
>> +			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK);
>> +
>> +	/* get the mux parents */
>> +	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
>> +		char name[16];
>> +
>> +		snprintf(name, sizeof(name), "clkin%d", i);
>> +		clk = devm_clk_get(nfc->dev, name);
>> +		if (IS_ERR(clk)) {
>> +			if (clk != ERR_PTR(-EPROBE_DEFER))
>> +				dev_err(nfc->dev, "Missing clock %s\n", name);
>> +			return PTR_ERR(clk);
>> +		}
>> +
>> +		sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
>> +	}
>> +
>> +	mux->map = nfc->reg_clk;
>> +	clk = devm_clk_register(nfc->dev, &mux->hw);
>> +	if (WARN_ON(IS_ERR(clk)))
>> +		return PTR_ERR(clk);
>> +
>> +	div->map = nfc->reg_clk;
>> +	nfc->device_clk = devm_clk_register(nfc->dev, &div->hw);
>> +	if (WARN_ON(IS_ERR(nfc->device_clk)))
>> +		return PTR_ERR(nfc->device_clk);
>> +
>> +	ret = clk_prepare_enable(nfc->core_clk);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "failed to enable core clk\n");
>> +		return ret;
>> +	}
>> +
>> +	ret = clk_prepare_enable(nfc->device_clk);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "failed to enable device clk\n");
>> +		clk_disable_unprepare(nfc->core_clk);
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
> 
> 
> As said above, I don't like having a clk driver here, especially since
> the registers you're accessing are not part of the NAND controller
> registers. Please try to create a driver in drivers/clk/ for that.
> 

already addressed this as in preivous comment

>> +
>> +static void meson_nfc_disable_clk(struct meson_nfc *nfc)
>> +{
>> +	clk_disable_unprepare(nfc->device_clk);
>> +	clk_disable_unprepare(nfc->core_clk);
>> +}
>> +
>> +static int meson_nfc_buffer_init(struct mtd_info *mtd)
>> +{
>> +	struct nand_chip *nand = mtd_to_nand(mtd);
>> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
>> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
>> +	struct device *dev = nfc->dev;
>> +	int info_bytes, page_bytes;
>> +	int nsectors;
>> +
>> +	nsectors = mtd->writesize / nand->ecc.size;
>> +	info_bytes = nsectors * PER_INFO_BYTE;
>> +	page_bytes = mtd->writesize + mtd->oobsize;
>> +
>> +	if ((meson_chip->data_buf) && (meson_chip->info_buf))
>> +		return 0;
>> +
>> +	meson_chip->data_buf = devm_kzalloc(dev, page_bytes, GFP_KERNEL);
>> +	if (!meson_chip->data_buf)
>> +		return  -ENOMEM;
>> +
>> +	meson_chip->info_buf = devm_kzalloc(dev, info_bytes, GFP_KERNEL);
>> +	if (!meson_chip->info_buf)
>> +		return  -ENOMEM;
> 
> You're doing DMA on those buffers, and devm_kzalloc() is not
> DMA-friendly (returned buffers are not aligned on a cache line). Also,
> you don't have to allocate your own buffers because the core already
> allocate them (chip->data_buf, chip->oob_poi). All you need to do is
> set the NAND_USE_BOUNCE_BUFFER flag in chip->options to make sure
> you're always passed a DMA-able buffer.
> 

thanks for the suggestion, we've migrated to use the
dmam_alloc_coherent() API


>> +
>> +	return 0;
>> +}
>> +
>> +static int meson_nfc_calc_set_timing(struct meson_nfc *nfc,
>> +				int rc_min, int rea_max, int rhoh_min)
>> +{
>> +	int div, bt_min, bt_max, bus_timing;
>> +	int ret;
>> +
>> +	div = DIV_ROUND_UP((rc_min / 1000), NFC_CLK_CYCLE);
>> +	ret = clk_set_rate(nfc->device_clk, 1000000000 / div);
>> +	if (ret) {
>> +		dev_err(nfc->dev, "failed to set nand clock rate\n");
>> +		return ret;
>> +	}
>> +
>> +	bt_min = (rea_max + NFC_DEFAULT_DELAY) / div;
>> +	bt_max = (NFC_DEFAULT_DELAY + rhoh_min + rc_min / 2) / div;
>> +
>> +	bt_min = DIV_ROUND_UP(bt_min, 1000);
>> +	bt_max = DIV_ROUND_UP(bt_max, 1000);
>> +
>> +	if (bt_max < bt_min)
>> +		return -EINVAL;
>> +
>> +	bus_timing = (bt_min + bt_max) / 2 + 1;
>> +
>> +	writel((1 << 21), nfc->reg_base + NFC_REG_CFG);
>> +	writel((NFC_CLK_CYCLE - 1) | (bus_timing << 5),
>> +				nfc->reg_base + NFC_REG_CFG);
>> +
>> +	writel((1 << 31), nfc->reg_base + NFC_REG_CMD);
>> +
>> +	return 0;
>> +}
>> +
>> +static int meson_nfc_setup_data_interface(struct mtd_info *mtd, int csline,
>> +				const struct nand_data_interface *conf)
>> +{
>> +	struct nand_chip *nand = mtd_to_nand(mtd);
>> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
>> +	const struct nand_sdr_timings *timings;
>> +
>> +	timings = nand_get_sdr_timings(conf);
>> +	if (IS_ERR(timings))
>> +		return -ENOTSUPP;
>> +
>> +	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
>> +		return 0;
>> +
>> +	meson_nfc_calc_set_timing(nfc, timings->tRC_min,
>> +				timings->tREA_max, timings->tRHOH_min);
>> +
>> +	return 0;
>> +}
>> +
>> +static int meson_nfc_get_nand_chip_dts(struct meson_nfc *nfc,
>> +		struct meson_nfc_nand_chip *chip, struct device_node *np)
>> +{
>> +	struct device *dev = nfc->dev;
>> +
>> +	if (of_property_read_u32(np, "reg", &chip->cs)) {
>> +		dev_err(dev, "can not get ce number\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (chip->cs > MAX_CE_NUM) {
>> +		dev_err(dev, "ce number is beyond\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (of_property_read_u32(np, "meson-nand-user-mode", &chip->user_mode)) {
>> +		dev_err(dev, "can not get user oob mode\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if ((chip->user_mode != NFC_USER2_OOB_BYTES)
>> +			|| (chip->user_mode != NFC_USER16_OOB_BYTES))
>> +		chip->user_mode = NFC_USER2_OOB_BYTES;
>> +
>> +	if (of_property_read_u32(np, "meson-nand-ran-mode", &chip->rand_mode)) {
>> +		dev_err(dev, "can not get scramble mode\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int meson_nfc_nand_chip_init(struct device *dev, struct meson_nfc *nfc,
>> +				  struct device_node *np)
>> +{
>> +	struct meson_nfc_nand_chip *chip;
>> +	struct nand_chip *nand;
>> +	struct mtd_info *mtd;
>> +	int ret;
>> +
>> +	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
>> +	if (!chip)
>> +		return -ENOMEM;
>> +
>> +	ret = meson_nfc_get_nand_chip_dts(nfc, chip, np);
> 
> Is there a really a need for putting this code in a separate function?
> Do you plan to support non-DT platforms?
> 

No, we don't plan to support non-DT platfrom, will fix this


>> +	if (ret)
>> +		return ret;
>> +
>> +	nand = &chip->nand;
>> +	nand_set_flash_node(nand, np);
>> +	nand_set_controller_data(nand, nfc);
>> +
>> +	nand->options |= NAND_USE_BOUNCE_BUFFER;
>> +	nand->select_chip = meson_nfc_select_chip;
>> +	nand->write_byte = meson_nfc_write_byte;
>> +	nand->write_buf = meson_nfc_write_buf;
>> +	nand->read_byte = meson_nfc_read_byte;
>> +	nand->read_buf = meson_nfc_read_buf;
>> +	nand->cmd_ctrl = meson_nfc_cmd_ctrl;
> 
> ->{write,read}_byte(), ->{write,read}_buf(), ->cmd_ctrl() should be
> replaced by ->exec_op().
> 

we have implemented a version of exec_op() , we really appreciate if you
can help to review this.

>> +	nand->setup_data_interface = meson_nfc_setup_data_interface;
>> +
>> +	nand->chip_delay = 200;
> 
> This should not be needed if you implement ->exec_op() and
> ->setup_data_interface().
> 
will drop this

>> +	nand->ecc.mode = NAND_ECC_HW;
>> +
>> +	nand->ecc.write_page_raw = meson_nfc_write_page_raw;
>> +	nand->ecc.write_page = meson_nfc_write_page_hwecc;
>> +	nand->ecc.write_oob_raw = nand_write_oob_std;
>> +	nand->ecc.write_oob = nand_write_oob_std;
>> +
>> +	nand->ecc.read_page_raw = meson_nfc_read_page_raw;
>> +	nand->ecc.read_page = meson_nfc_read_page_hwecc;
>> +	nand->ecc.read_oob_raw = meson_nfc_read_oob_raw;
>> +	nand->ecc.read_oob = meson_nfc_read_oob;
>> +
>> +	mtd = nand_to_mtd(nand);
>> +	mtd->owner = THIS_MODULE;
>> +	mtd->dev.parent = dev;
>> +	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
>> +				   "%s:nand", dev_name(dev));
>> +	if (!mtd->name) {
>> +		dev_err(nfc->dev, "Failed to allocate mtd->name\n");
>> +		return -ENOMEM;
>> +	}
> 
> You set the name after nand_scan_ident() and make it conditional (only
> if ->name == NULL) so that the label property defined in the DT takes
> precedence over the default name.

we can do this, but as second consideration, we'd prefer simply to drop
this customization of mtd->name here (we didn't understand your next cs
id suggestion).

> Also, I recommend suffixing this name
> with the CS id, just in case you ever need to support connecting several
> chips to the same controller. 
> 

we actually didn't get the point here, cs is about chip selection with
multiple nand chip? and how to get this information?


>> +
>> +	mtd_set_ooblayout(mtd, &meson_ooblayout_ops);
> 
> We usually assign the OOB layout when we know which ECC engine will be
> used. Here that works because you only support ECC_HW, but I think it's
> preferable to move that in your ECC init function.
> 

Ok, will do

>> +
>> +	ret = nand_scan_ident(mtd, 1, NULL);
>> +	if (ret) {
>> +		dev_err(dev, "failed to can ident\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	/* store bbt magic in page, cause OOB is not protected */
>> +	if (nand->bbt_options & NAND_BBT_USE_FLASH)
>> +		nand->bbt_options |= NAND_BBT_NO_OOB;
>> +
>> +	nand->options |= NAND_NO_SUBPAGE_WRITE;
>> +
>> +	ret = meson_nfc_ecc_init(dev, mtd);
>> +	if (ret) {
>> +		dev_err(dev, "failed to ecc init\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (nand->options & NAND_BUSWIDTH_16) {
>> +		dev_err(dev, "16bits buswidth not supported");
>> +		return -EINVAL;
>> +	}
>> +
>> +	ret = meson_nfc_buffer_init(mtd);
>> +	if (ret)
>> +		return -ENOMEM;
>> +
>> +	ret = nand_scan_tail(mtd);
>> +	if (ret)
>> +		return -ENODEV;
>> +
>> +	ret = mtd_device_register(mtd, NULL, 0);
>> +	if (ret) {
>> +		dev_err(dev, "failed to register mtd device: %d\n", ret);
>> +		nand_release(mtd);
> 
> You should call nand_cleanup() not call nand_release().
> 
ok, will fix

>> +		return ret;
>> +	}
>> +
>> +	list_add_tail(&chip->node, &nfc->chips);
>> +
>> +	return 0;
>> +}
>> +
>> +static int meson_nfc_nand_chips_init(struct device *dev, struct meson_nfc *nfc)
>> +{
>> +	struct device_node *np = dev->of_node;
>> +	struct device_node *nand_np;
>> +	int ret;
>> +
>> +	for_each_child_of_node(np, nand_np) {
>> +		ret = meson_nfc_nand_chip_init(dev, nfc, nand_np);
>> +		if (ret) {
>> +			of_node_put(nand_np);
> 
> You don't need to call of_node_put(), for_each_child_of_node() will do
> that for you.
> 

ok, will drop this


>> +			return ret;
> 
> You should remove all chips that have been added in case of error.
> 
will fix this.

>> +		}
>> +	}
>> +	return 0;
>> +}
>> +
>> +static irqreturn_t meson_nfc_irq(int irq, void *id)
>> +{
>> +	struct meson_nfc *nfc = id;
>> +	u32 cfg;
>> +
>> +	cfg = readl(nfc->reg_base + NFC_REG_CFG);
>> +	cfg |= (1 << 21);
>> +	writel(cfg, nfc->reg_base + NFC_REG_CFG);
>> +
>> +	complete(&nfc->completion);
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static const struct meson_nfc_data meson_gxl_data = {
>> +	.short_bch	= NFC_ECC_BCH60_1K,
>> +	.ecc		= meson_gxl_ecc,
>> +	.ecc_num	= ARRAY_SIZE(meson_gxl_ecc),
>> +};
>> +
>> +static const struct meson_nfc_data meson_axg_data = {
>> +	.short_bch	= NFC_ECC_BCH8_1K,
>> +	.ecc		= meson_axg_ecc,
>> +	.ecc_num	= ARRAY_SIZE(meson_axg_ecc),
>> +};
>> +
>> +static const struct of_device_id meson_nfc_id_table[] = {
>> +	{
>> +		.compatible = "amlogic,meson-gxl-nfc",
>> +		.data = &meson_gxl_data,
>> +	}, {
>> +		.compatible = "amlogic,meson-axg-nfc",
>> +		.data = &meson_axg_data,
>> +	},
>> +	{}
>> +};
>> +MODULE_DEVICE_TABLE(of, meson_nfc_id_table);
>> +
>> +static int meson_nfc_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct meson_nfc *nfc;
>> +	struct resource *res;
>> +	const struct of_device_id *of_nfc_id;
>> +	int ret, irq;
>> +
>> +	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
>> +	if (!nfc)
>> +		return -ENOMEM;
>> +
>> +	of_nfc_id = of_match_device(meson_nfc_id_table, &pdev->dev);
>> +	if (!of_nfc_id)
>> +		return -ENODEV;
>> +
>> +	nfc->data = (struct meson_nfc_data *)of_nfc_id->data;
>> +
>> +	spin_lock_init(&nfc->controller.lock);
>> +	init_waitqueue_head(&nfc->controller.wq);
>> +	INIT_LIST_HEAD(&nfc->chips);
>> +
>> +	nfc->dev = dev;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	if (!res) {
>> +		dev_err(dev, "Failed to nfc reg resource\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	nfc->reg_base = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(nfc->reg_base)) {
>> +		dev_err(dev, "Failed to lookup nfi reg base\n");
>> +		return PTR_ERR(nfc->reg_base);
>> +	}
>> +
>> +	nfc->reg_clk = syscon_regmap_lookup_by_phandle(dev->of_node,
>> +							"amlogic,mmc-syscon");
>> +	if (IS_ERR(nfc->reg_clk)) {
>> +		dev_err(dev, "Failed to lookup clock base\n");
>> +		return PTR_ERR(nfc->reg_clk);
>> +	}
>> +
>> +	irq = platform_get_irq(pdev, 0);
>> +	if (irq < 0) {
>> +		dev_err(dev, "no nfi irq resource\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	ret = meson_nfc_clk_init(nfc);
>> +	if (ret) {
>> +		dev_err(dev, "failed to initialize nand clk\n");
>> +		goto err_clk;
>> +	}
>> +
>> +	ret = devm_request_irq(dev, irq, meson_nfc_irq, 0, dev_name(dev), nfc);
>> +	if (ret) {
>> +		dev_err(dev, "failed to request nfi irq\n");
>> +		ret = -EINVAL;
>> +		goto err_clk;
>> +	}
>> +
>> +	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
>> +	if (ret) {
>> +		dev_err(dev, "failed to set dma mask\n");
>> +		goto err_clk;
>> +	}
>> +
>> +	platform_set_drvdata(pdev, nfc);
>> +
>> +	ret = meson_nfc_nand_chips_init(dev, nfc);
>> +	if (ret) {
>> +		dev_err(dev, "failed to init nand chips\n");
>> +		goto err_clk;
>> +	}
>> +
>> +	meson_nfc_page0_gen(nfc);
>> +	return 0;
>> +
>> +err_clk:
>> +	clk_disable_unprepare(nfc->device_clk);
>> +	clk_disable_unprepare(nfc->core_clk);
> 
> Why not meson_nfc_disable_clk()?
> 

good idea, will fix

>> +
>> +	return ret;
>> +}
>> +
>> +static int meson_nfc_remove(struct platform_device *pdev)
>> +{
>> +	struct meson_nfc *nfc = platform_get_drvdata(pdev);
>> +	struct meson_nfc_nand_chip *chip;
>> +
>> +	while (!list_empty(&nfc->chips)) {
>> +		chip = list_first_entry(&nfc->chips, struct meson_nfc_nand_chip,
>> +					node);
>> +		nand_release(nand_to_mtd(&chip->nand));
> 
> Please use mtd_device_unregister() + nand_cleanup(), and check the
> return value of mtd_device_unregister() before calling nand_cleanup().
> 
Ok

>> +		list_del(&chip->node);
>> +	}
>> +
>> +	meson_nfc_disable_clk(nfc);
>> +
>> +	platform_set_drvdata(pdev, NULL);
>> +
>> +	return 0;
>> +}
>> +
>> +static struct platform_driver meson_nfc_driver = {
>> +	.probe  = meson_nfc_probe,
>> +	.remove = meson_nfc_remove,
>> +	.driver = {
>> +		.name  = "meson_nand",
> 
> If you don't mind, I prefer "meson-nand" :-).
sure

> 
>> +		.of_match_table = meson_nfc_id_table,
>> +	},
>> +};
>> +
> 
> Can you remove this blank line?
> 
sure

>> +module_platform_driver(meson_nfc_driver);
>> +
>> +MODULE_LICENSE("Dual MIT/GPL");
>> +MODULE_AUTHOR("Liang Yang <liang.yang@amlogic.com>");
>> +MODULE_DESCRIPTION("Amlogic's Meson NAND Flash Controller driver");
> 
> I probably missed a lot of other things, but that should be enough to
> start working on a v2.
> 
thanks a lot for the review

> Regards,
> 
> Boris
> 
> [1]https://elixir.bootlin.com/u-boot/v2018.07-rc2/source/tools/sunxi-spl-image-builder.c
> [2]http://patchwork.ozlabs.org/patch/931984/
> 
> _______________________________________________
> linux-amlogic mailing list
> linux-amlogic@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-amlogic
> 
> .
>
Boris Brezillon July 18, 2018, 7:08 p.m. | #10
Hi Yixun,

On Wed, 18 Jul 2018 17:38:56 +0800
Yixun Lan <yixun.lan@amlogic.com> wrote:

> >> +
> >> +#define NFC_REG_CMD		0x00
> >> +#define NFC_REG_CFG		0x04
> >> +#define NFC_REG_DADR		0x08
> >> +#define NFC_REG_IADR		0x0c
> >> +#define NFC_REG_BUF		0x10
> >> +#define NFC_REG_INFO		0x14
> >> +#define NFC_REG_DC		0x18
> >> +#define NFC_REG_ADR		0x1c
> >> +#define NFC_REG_DL		0x20
> >> +#define NFC_REG_DH		0x24
> >> +#define NFC_REG_CADR		0x28
> >> +#define NFC_REG_SADR		0x2c
> >> +#define NFC_REG_PINS		0x30
> >> +#define NFC_REG_VER		0x38
> >> +  
> > 
> > Can you put the reg offsets next to their field definitions?
> >   
> actually, we would prefer to put all the CMD definition below the reg
> offset, so it will better reflect what's it belong to.

Just to be clear, I meant something like:

#define NFC_CMD				0x00
#define NFC_CMD_DRD			(0x8 << 14)
#define NFC_CMD_IDLE			(0xc << 14)
...

#define NFC_CFG				0x04
#define NFC_CFG_XXX			xxx
...

I find it easier to guess which register the fields are attached to when
it's defined like that, but I won't block the driver for such a tiny
detail. 

> >> +static void meson_nfc_cmd_ctrl(struct mtd_info *mtd,
> >> +					int cmd, unsigned int ctrl)  
> >   
> > ->cmd_ctrl() has recently been deprecated in favor of ->exec_op(). You  
> > can have a look at the marvell, v610 or fsmc drivers if you want to
> > have an idea of how ->exec_op() should be implemented. Miquel and I are
> > also here to help if you have any questions.
> >   
> 
> follow your suggestion, we have implemented the exec_op() interface,
> we'd really appreciate if you can help to review this ..

Sure, just send a v2 and we'll review it.


> >> +
> >> +static void meson_nfc_cmd_m2n(struct meson_nfc *nfc, int raw)  
> > 
> > n2m -> nand2mem ?
> >   
> yes, it is

Then please use nand2mem, it's clearer.

> >> +static int meson_nfc_wait_dma_finish(struct meson_nfc *nfc)
> >> +{
> >> +	meson_nfc_cmd_idle(nfc, 0);
> >> +	meson_nfc_cmd_idle(nfc, 0);  
> > 
> > Two calls to cmd_idle(), is this expected or a copy&paste error? If
> > that's expected it definitely deserves a comment explaining why?
> >   
> 
> yes, it is intentional
> 
> we will put these comments into the function.
> 	/*
>          * The Nand flash controller is designed as two stages pipleline -
>          *  a) fetch and b) excute.
>          * So, there might be cases when the driver see command queue is
> empty,
>          * but the Nand flash controller still has two commands buffered,
>          * one is fetched into NFC request queue (ready to run), and another
>          * is actively executing.
>          */
> 

So pushing 2 "IDLE" commands guarantees that the pipeline is emptied,
right? The comment looks incomplete, you should explain what those
meson_nfc_cmd_idle() are for.

> >> +static int meson_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
> >> +{
> >> +	struct nand_chip *nand = mtd_to_nand(mtd);
> >> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> >> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
> >> +	struct meson_nand_ecc *meson_ecc = nfc->data->ecc;
> >> +	int num = nfc->data->ecc_num;
> >> +	int nsectors, i, bytes;
> >> +
> >> +	/* support only ecc hw mode */
> >> +	if (nand->ecc.mode != NAND_ECC_HW) {  
> > 
> > Given that you support raw accesses, I'm pretty sure you can support
> > ECC_NONE, ECC_SOFT and ECC_ON_DIE with zero effort.
> >   
> 
> is this a block for this driver to be accepted by upstream?

Nope.

> otherwise we'd like to implement this feature later in separate patch.
> 

That's fine.

> >> +	nsectors = mtd->writesize / nand->ecc.size;
> >> +	bytes =(meson_chip->user_mode == NFC_USER2_OOB_BYTES) ? nsectors * 2 : 16;
> >> +	if (mtd->oobsize < (nand->ecc.bytes * nsectors + bytes))
> >> +		return -EINVAL;  
> > 
> > It's probably worth looking at what is being proposed here [2] for the
> > ECC config selection logic.
> >   
> 
> sure, we'd happy to adopt the ECC config helper function, and seems it
> is possible ;-)
> 
> sounds the proposed ECC config patch is still under review, and we
> would like to adjust our code once it's ready (probably we will still
> keep this version in patch v2, then address it in v3 later)

It's been merged, and should be available in the nand/next branch [1].

> >> +static int meson_nfc_buffer_init(struct mtd_info *mtd)
> >> +{
> >> +	struct nand_chip *nand = mtd_to_nand(mtd);
> >> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
> >> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
> >> +	struct device *dev = nfc->dev;
> >> +	int info_bytes, page_bytes;
> >> +	int nsectors;
> >> +
> >> +	nsectors = mtd->writesize / nand->ecc.size;
> >> +	info_bytes = nsectors * PER_INFO_BYTE;
> >> +	page_bytes = mtd->writesize + mtd->oobsize;
> >> +
> >> +	if ((meson_chip->data_buf) && (meson_chip->info_buf))
> >> +		return 0;
> >> +
> >> +	meson_chip->data_buf = devm_kzalloc(dev, page_bytes, GFP_KERNEL);
> >> +	if (!meson_chip->data_buf)
> >> +		return  -ENOMEM;
> >> +
> >> +	meson_chip->info_buf = devm_kzalloc(dev, info_bytes, GFP_KERNEL);
> >> +	if (!meson_chip->info_buf)
> >> +		return  -ENOMEM;  
> > 
> > You're doing DMA on those buffers, and devm_kzalloc() is not
> > DMA-friendly (returned buffers are not aligned on a cache line). Also,
> > you don't have to allocate your own buffers because the core already
> > allocate them (chip->data_buf, chip->oob_poi). All you need to do is
> > set the NAND_USE_BOUNCE_BUFFER flag in chip->options to make sure
> > you're always passed a DMA-able buffer.
> >   
> 
> thanks for the suggestion, we've migrated to use the
> dmam_alloc_coherent() API

kzalloc() should be just fine, no need to alloc a DMA coherent region. 


> 
> >> +	nand->setup_data_interface = meson_nfc_setup_data_interface;
> >> +
> >> +	nand->chip_delay = 200;  
> > 
> > This should not be needed if you implement ->exec_op() and  
> > ->setup_data_interface().  
> >   
> will drop this
> 
> >> +	nand->ecc.mode = NAND_ECC_HW;
> >> +
> >> +	nand->ecc.write_page_raw = meson_nfc_write_page_raw;
> >> +	nand->ecc.write_page = meson_nfc_write_page_hwecc;
> >> +	nand->ecc.write_oob_raw = nand_write_oob_std;
> >> +	nand->ecc.write_oob = nand_write_oob_std;
> >> +
> >> +	nand->ecc.read_page_raw = meson_nfc_read_page_raw;
> >> +	nand->ecc.read_page = meson_nfc_read_page_hwecc;
> >> +	nand->ecc.read_oob_raw = meson_nfc_read_oob_raw;
> >> +	nand->ecc.read_oob = meson_nfc_read_oob;
> >> +
> >> +	mtd = nand_to_mtd(nand);
> >> +	mtd->owner = THIS_MODULE;
> >> +	mtd->dev.parent = dev;
> >> +	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
> >> +				   "%s:nand", dev_name(dev));
> >> +	if (!mtd->name) {
> >> +		dev_err(nfc->dev, "Failed to allocate mtd->name\n");
> >> +		return -ENOMEM;
> >> +	}  
> > 
> > You set the name after nand_scan_ident() and make it conditional (only
> > if ->name == NULL) so that the label property defined in the DT takes
> > precedence over the default name.  
> 
> we can do this, but as second consideration, we'd prefer simply to drop
> this customization of mtd->name here (we didn't understand your next cs
> id suggestion).

No, you really should set a well-known name, so that people can pass
mtdparts on the kernel command line.

> 
> > Also, I recommend suffixing this name
> > with the CS id, just in case you ever need to support connecting several
> > chips to the same controller. 
> >   
> 
> we actually didn't get the point here, cs is about chip selection with
> multiple nand chip? and how to get this information?

Well, you currently seem to only support one chip per controller, but I
guess the IP can handle several CS lines. So my recommendation is about
choosing a name so that you can later easily add support for multiple
chips without breaking setups where mtdparts is used.

To sum-up, assuming your NAND chip is always connected to CS0 (on the
controller side), I'd suggest doing:

	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
				   "%s:nand.%d", dev_name(dev), cs_id);

where cs_id is the value you extracted from the reg property of the
NAND node.

Regards,

Boris

[1]http://git.infradead.org/linux-mtd.git/shortlog/refs/heads/nand/next
Yixun Lan July 19, 2018, 8:13 a.m. | #11
HI Boris:

thanks for the quick response.

On 07/19/18 03:08, Boris Brezillon wrote:
> Hi Yixun,
> 
> On Wed, 18 Jul 2018 17:38:56 +0800
> Yixun Lan <yixun.lan@amlogic.com> wrote:
> 
>>>> +
>>>> +#define NFC_REG_CMD		0x00
>>>> +#define NFC_REG_CFG		0x04
>>>> +#define NFC_REG_DADR		0x08
>>>> +#define NFC_REG_IADR		0x0c
>>>> +#define NFC_REG_BUF		0x10
>>>> +#define NFC_REG_INFO		0x14
>>>> +#define NFC_REG_DC		0x18
>>>> +#define NFC_REG_ADR		0x1c
>>>> +#define NFC_REG_DL		0x20
>>>> +#define NFC_REG_DH		0x24
>>>> +#define NFC_REG_CADR		0x28
>>>> +#define NFC_REG_SADR		0x2c
>>>> +#define NFC_REG_PINS		0x30
>>>> +#define NFC_REG_VER		0x38
>>>> +  
>>>
>>> Can you put the reg offsets next to their field definitions?
>>>   
>> actually, we would prefer to put all the CMD definition below the reg
>> offset, so it will better reflect what's it belong to.
> 
> Just to be clear, I meant something like:
> 
> #define NFC_CMD				0x00
> #define NFC_CMD_DRD			(0x8 << 14)
> #define NFC_CMD_IDLE			(0xc << 14)
> ...
> 
> #define NFC_CFG				0x04
> #define NFC_CFG_XXX			xxx
> ...
> 
> I find it easier to guess which register the fields are attached to when
> it's defined like that, but I won't block the driver for such a tiny
> detail. 
> 
yes, this is exactly what I mean

>>>> +static void meson_nfc_cmd_ctrl(struct mtd_info *mtd,
>>>> +					int cmd, unsigned int ctrl)  
>>>   
>>> ->cmd_ctrl() has recently been deprecated in favor of ->exec_op(). You  
>>> can have a look at the marvell, v610 or fsmc drivers if you want to
>>> have an idea of how ->exec_op() should be implemented. Miquel and I are
>>> also here to help if you have any questions.
>>>   
>>
>> follow your suggestion, we have implemented the exec_op() interface,
>> we'd really appreciate if you can help to review this ..
> 
> Sure, just send a v2 and we'll review it.
> 
> 
>>>> +
>>>> +static void meson_nfc_cmd_m2n(struct meson_nfc *nfc, int raw)  
>>>
>>> n2m -> nand2mem ?
>>>   
>> yes, it is
> 
> Then please use nand2mem, it's clearer.
we end at dropping the n2m function. by converting them into

static void
meson_nfc_cmd_access(
struct meson_nfc *nfc,
struct mtd_info *mtd, int raw, bool dir)


> 
>>>> +static int meson_nfc_wait_dma_finish(struct meson_nfc *nfc)
>>>> +{
>>>> +	meson_nfc_cmd_idle(nfc, 0);
>>>> +	meson_nfc_cmd_idle(nfc, 0);  
>>>
>>> Two calls to cmd_idle(), is this expected or a copy&paste error? If
>>> that's expected it definitely deserves a comment explaining why?
>>>   
>>
>> yes, it is intentional
>>
>> we will put these comments into the function.
>> 	/*
>>          * The Nand flash controller is designed as two stages pipleline -
>>          *  a) fetch and b) excute.
>>          * So, there might be cases when the driver see command queue is
>> empty,
>>          * but the Nand flash controller still has two commands buffered,
>>          * one is fetched into NFC request queue (ready to run), and another
>>          * is actively executing.
>>          */
>>
> 
> So pushing 2 "IDLE" commands guarantees that the pipeline is emptied,
> right? The comment looks incomplete, you should explain what those
> meson_nfc_cmd_idle() are for.
> 
thanks

the meson_nfc_cmd_idle() function itself is quite straightforward, and
we feel explain that inserting 2 "IDLE" commands to drain out the
pipeline is enough.

>>>> +static int meson_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
>>>> +{
>>>> +	struct nand_chip *nand = mtd_to_nand(mtd);
>>>> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
>>>> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
>>>> +	struct meson_nand_ecc *meson_ecc = nfc->data->ecc;
>>>> +	int num = nfc->data->ecc_num;
>>>> +	int nsectors, i, bytes;
>>>> +
>>>> +	/* support only ecc hw mode */
>>>> +	if (nand->ecc.mode != NAND_ECC_HW) {  
>>>
>>> Given that you support raw accesses, I'm pretty sure you can support
>>> ECC_NONE, ECC_SOFT and ECC_ON_DIE with zero effort.
>>>   
>>
>> is this a block for this driver to be accepted by upstream?
> 
> Nope.
> 
>> otherwise we'd like to implement this feature later in separate patch.
>>
> 
> That's fine.
> 
>>>> +	nsectors = mtd->writesize / nand->ecc.size;
>>>> +	bytes =(meson_chip->user_mode == NFC_USER2_OOB_BYTES) ? nsectors * 2 : 16;
>>>> +	if (mtd->oobsize < (nand->ecc.bytes * nsectors + bytes))
>>>> +		return -EINVAL;  
>>>
>>> It's probably worth looking at what is being proposed here [2] for the
>>> ECC config selection logic.
>>>   
>>
>> sure, we'd happy to adopt the ECC config helper function, and seems it
>> is possible ;-)
>>
>> sounds the proposed ECC config patch is still under review, and we
>> would like to adjust our code once it's ready (probably we will still
>> keep this version in patch v2, then address it in v3 later)
> 
> It's been merged, and should be available in the nand/next branch [1].
> 
em... I'd leave this to Liang Yang to implement this, so it's not fixed
in next PATCH v2, but will address this in v3.

thanks

>>>> +static int meson_nfc_buffer_init(struct mtd_info *mtd)
>>>> +{
>>>> +	struct nand_chip *nand = mtd_to_nand(mtd);
>>>> +	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
>>>> +	struct meson_nfc *nfc = nand_get_controller_data(nand);
>>>> +	struct device *dev = nfc->dev;
>>>> +	int info_bytes, page_bytes;
>>>> +	int nsectors;
>>>> +
>>>> +	nsectors = mtd->writesize / nand->ecc.size;
>>>> +	info_bytes = nsectors * PER_INFO_BYTE;
>>>> +	page_bytes = mtd->writesize + mtd->oobsize;
>>>> +
>>>> +	if ((meson_chip->data_buf) && (meson_chip->info_buf))
>>>> +		return 0;
>>>> +
>>>> +	meson_chip->data_buf = devm_kzalloc(dev, page_bytes, GFP_KERNEL);
>>>> +	if (!meson_chip->data_buf)
>>>> +		return  -ENOMEM;
>>>> +
>>>> +	meson_chip->info_buf = devm_kzalloc(dev, info_bytes, GFP_KERNEL);
>>>> +	if (!meson_chip->info_buf)
>>>> +		return  -ENOMEM;  
>>>
>>> You're doing DMA on those buffers, and devm_kzalloc() is not
>>> DMA-friendly (returned buffers are not aligned on a cache line). Also,
>>> you don't have to allocate your own buffers because the core already
>>> allocate them (chip->data_buf, chip->oob_poi). All you need to do is
>>> set the NAND_USE_BOUNCE_BUFFER flag in chip->options to make sure
>>> you're always passed a DMA-able buffer.
>>>   
>>
>> thanks for the suggestion, we've migrated to use the
>> dmam_alloc_coherent() API
> 
> kzalloc() should be just fine, no need to alloc a DMA coherent region. 
> 

we're a little bit confused here, isn't devm_kzalloc (previously we are
using) a variant of kzalloc? and since the NAND controller is doing DMA
here, using DMA coherent API is more proper way?

> 
>>
>>>> +	nand->setup_data_interface = meson_nfc_setup_data_interface;
>>>> +
>>>> +	nand->chip_delay = 200;  
>>>
>>> This should not be needed if you implement ->exec_op() and  
>>> ->setup_data_interface().  
>>>   
>> will drop this
>>
>>>> +	nand->ecc.mode = NAND_ECC_HW;
>>>> +
>>>> +	nand->ecc.write_page_raw = meson_nfc_write_page_raw;
>>>> +	nand->ecc.write_page = meson_nfc_write_page_hwecc;
>>>> +	nand->ecc.write_oob_raw = nand_write_oob_std;
>>>> +	nand->ecc.write_oob = nand_write_oob_std;
>>>> +
>>>> +	nand->ecc.read_page_raw = meson_nfc_read_page_raw;
>>>> +	nand->ecc.read_page = meson_nfc_read_page_hwecc;
>>>> +	nand->ecc.read_oob_raw = meson_nfc_read_oob_raw;
>>>> +	nand->ecc.read_oob = meson_nfc_read_oob;
>>>> +
>>>> +	mtd = nand_to_mtd(nand);
>>>> +	mtd->owner = THIS_MODULE;
>>>> +	mtd->dev.parent = dev;
>>>> +	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
>>>> +				   "%s:nand", dev_name(dev));
>>>> +	if (!mtd->name) {
>>>> +		dev_err(nfc->dev, "Failed to allocate mtd->name\n");
>>>> +		return -ENOMEM;
>>>> +	}  
>>>
>>> You set the name after nand_scan_ident() and make it conditional (only
>>> if ->name == NULL) so that the label property defined in the DT takes
>>> precedence over the default name.  
>>
for setting mtd->name conditional, do you mean doing something like this?

if (!mtd->name)
	mtd->name = devm_kasprintf(..)

but we found mtd->name = "ffe07800.nfc" after function
nand_scan_ident(), which is same value as dev_name(dev)..
and there is no cs information encoded there.


>> we can do this, but as second consideration, we'd prefer simply to drop
>> this customization of mtd->name here (we didn't understand your next cs
>> id suggestion).
> 
> No, you really should set a well-known name, so that people can pass
> mtdparts on the kernel command line.
> 
ok

>>
>>> Also, I recommend suffixing this name
>>> with the CS id, just in case you ever need to support connecting several
>>> chips to the same controller. 
>>>   
>>
>> we actually didn't get the point here, cs is about chip selection with
>> multiple nand chip? and how to get this information?
> 
> Well, you currently seem to only support one chip per controller, but I
> guess the IP can handle several CS lines. So my recommendation is about
> choosing a name so that you can later easily add support for multiple
> chips without breaking setups where mtdparts is used.
> 
> To sum-up, assuming your NAND chip is always connected to CS0 (on the
> controller side), I'd suggest doing:
> 
yes, this is exactly how the hardware connected.
> 	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
> 				   "%s:nand.%d", dev_name(dev), cs_id);
> 
> where cs_id is the value you extracted from the reg property of the
> NAND node.
> 
Ok, you right.
current, the NAND chip is only use one CS (which CE0) for now, what's in
the DT is

nand@0 {
 reg = < 0 >;
 ..
};

so for the multiple chips it would something like this in DT?

nand@0 {
  reg = < 0 >;
};

nand@1 {
  reg = < 1 >;
};

or even
nand@0 {
  reg = < 0 2 >;
};

nand@1 {
  reg = < 3 4 >;
};

do we need to encode all the cs information here? not sure if we
understand this correctly, but could send out the patch for review..


> Regards,
> 
> Boris
> 
> [1]http://git.infradead.org/linux-mtd.git/shortlog/refs/heads/nand/next
> 
> .
>
Boris Brezillon July 19, 2018, 8:39 a.m. | #12
Hi Yixun,

On Thu, 19 Jul 2018 16:13:47 +0800
Yixun Lan <yixun.lan@amlogic.com> wrote:

> >>> You're doing DMA on those buffers, and devm_kzalloc() is not
> >>> DMA-friendly (returned buffers are not aligned on a cache line). Also,
> >>> you don't have to allocate your own buffers because the core already
> >>> allocate them (chip->data_buf, chip->oob_poi). All you need to do is
> >>> set the NAND_USE_BOUNCE_BUFFER flag in chip->options to make sure
> >>> you're always passed a DMA-able buffer.
> >>>     
> >>
> >> thanks for the suggestion, we've migrated to use the
> >> dmam_alloc_coherent() API  
> > 
> > kzalloc() should be just fine, no need to alloc a DMA coherent region. 
> >   
> 
> we're a little bit confused here, isn't devm_kzalloc (previously we are
> using) a variant of kzalloc? and since the NAND controller is doing DMA
> here, using DMA coherent API is more proper way?

Well, making buffers DMA coherent might be expensive, especially if you
access them a lot (unless you have a coherency unit and the cache is
kept enabled).

Regarding the "why is devm_kzalloc() is not DMA-safe?" question, I'd
recommend that you read this discussion [1].

> >>>> +	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
> >>>> +				   "%s:nand", dev_name(dev));
> >>>> +	if (!mtd->name) {
> >>>> +		dev_err(nfc->dev, "Failed to allocate mtd->name\n");
> >>>> +		return -ENOMEM;
> >>>> +	}    
> >>>
> >>> You set the name after nand_scan_ident() and make it conditional (only
> >>> if ->name == NULL) so that the label property defined in the DT takes
> >>> precedence over the default name.    
> >>  
> for setting mtd->name conditional, do you mean doing something like this?
> 
> if (!mtd->name)
> 	mtd->name = devm_kasprintf(..)

Yes, that's what I meant.

> 
> but we found mtd->name = "ffe07800.nfc" after function
> nand_scan_ident(), which is same value as dev_name(dev)..
> and there is no cs information encoded there.

Hm, that shouldn't be the case. Maybe you can add traces to find out
who is setting mtd->name to this value.

> 
> >>  
> >>> Also, I recommend suffixing this name
> >>> with the CS id, just in case you ever need to support connecting several
> >>> chips to the same controller. 
> >>>     
> >>
> >> we actually didn't get the point here, cs is about chip selection with
> >> multiple nand chip? and how to get this information?  
> > 
> > Well, you currently seem to only support one chip per controller, but I
> > guess the IP can handle several CS lines. So my recommendation is about
> > choosing a name so that you can later easily add support for multiple
> > chips without breaking setups where mtdparts is used.
> > 
> > To sum-up, assuming your NAND chip is always connected to CS0 (on the
> > controller side), I'd suggest doing:
> >   
> yes, this is exactly how the hardware connected.
> > 	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
> > 				   "%s:nand.%d", dev_name(dev), cs_id);
> > 
> > where cs_id is the value you extracted from the reg property of the
> > NAND node.
> >   
> Ok, you right.
> current, the NAND chip is only use one CS (which CE0) for now, what's in
> the DT is
> 
> nand@0 {
>  reg = < 0 >;
>  ..
> };
> 
> so for the multiple chips it would something like this in DT?
> 
> nand@0 {
>   reg = < 0 >;
> };
> 
> nand@1 {
>   reg = < 1 >;
> };

Yep, that's for 2 single-die chips.

> 
> or even
> nand@0 {
>   reg = < 0 2 >;
> };
> 
> nand@1 {

nand@3 {

>   reg = < 3 4 >;
> };

And this is describing 2 dual-die chips.

> 
> do we need to encode all the cs information here? not sure if we
> understand this correctly, but could send out the patch for review..

Yes, reg should contain an array of controller-side CS lines used to
select the chip (or a specific die in a chip, the index in the reg
table being the id of the die).

Regards,

Boris

[1]http://linux-arm-kernel.infradead.narkive.com/vyJqy0RQ/question-devm-kmalloc-for-dma
Yixun Lan July 19, 2018, 9:53 a.m. | #13
HI Boris


On 07/19/18 16:39, Boris Brezillon wrote:
> Hi Yixun,
> 
> On Thu, 19 Jul 2018 16:13:47 +0800
> Yixun Lan <yixun.lan@amlogic.com> wrote:
> 
>>>>> You're doing DMA on those buffers, and devm_kzalloc() is not
>>>>> DMA-friendly (returned buffers are not aligned on a cache line). Also,
>>>>> you don't have to allocate your own buffers because the core already
>>>>> allocate them (chip->data_buf, chip->oob_poi). All you need to do is
>>>>> set the NAND_USE_BOUNCE_BUFFER flag in chip->options to make sure
>>>>> you're always passed a DMA-able buffer.
>>>>>     
>>>>
>>>> thanks for the suggestion, we've migrated to use the
>>>> dmam_alloc_coherent() API  
>>>
>>> kzalloc() should be just fine, no need to alloc a DMA coherent region. 
>>>   
>>
>> we're a little bit confused here, isn't devm_kzalloc (previously we are
>> using) a variant of kzalloc? and since the NAND controller is doing DMA
>> here, using DMA coherent API is more proper way?
> 
> Well, making buffers DMA coherent might be expensive, especially if you
> access them a lot (unless you have a coherency unit and the cache is
> kept enabled).
> 
> Regarding the "why is devm_kzalloc() is not DMA-safe?" question, I'd
> recommend that you read this discussion [1].
> 
great, thanks for the info.

we fixed this in patch v2

>>>>>> +	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
>>>>>> +				   "%s:nand", dev_name(dev));
>>>>>> +	if (!mtd->name) {
>>>>>> +		dev_err(nfc->dev, "Failed to allocate mtd->name\n");
>>>>>> +		return -ENOMEM;
>>>>>> +	}    
>>>>>
>>>>> You set the name after nand_scan_ident() and make it conditional (only
>>>>> if ->name == NULL) so that the label property defined in the DT takes
>>>>> precedence over the default name.    
>>>>  
>> for setting mtd->name conditional, do you mean doing something like this?
>>
>> if (!mtd->name)
>> 	mtd->name = devm_kasprintf(..)
> 
> Yes, that's what I meant.
> 
>>
>> but we found mtd->name = "ffe07800.nfc" after function
>> nand_scan_ident(), which is same value as dev_name(dev)..
>> and there is no cs information encoded there.
> 
> Hm, that shouldn't be the case. Maybe you can add traces to find out
> who is setting mtd->name to this value.
> 
will trace this, then get back to you
>>
>>>>  
>>>>> Also, I recommend suffixing this name
>>>>> with the CS id, just in case you ever need to support connecting several
>>>>> chips to the same controller. 
>>>>>     
>>>>
>>>> we actually didn't get the point here, cs is about chip selection with
>>>> multiple nand chip? and how to get this information?  
>>>
>>> Well, you currently seem to only support one chip per controller, but I
>>> guess the IP can handle several CS lines. So my recommendation is about
>>> choosing a name so that you can later easily add support for multiple
>>> chips without breaking setups where mtdparts is used.
>>>
>>> To sum-up, assuming your NAND chip is always connected to CS0 (on the
>>> controller side), I'd suggest doing:
>>>   
>> yes, this is exactly how the hardware connected.
>>> 	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
>>> 				   "%s:nand.%d", dev_name(dev), cs_id);
>>>
>>> where cs_id is the value you extracted from the reg property of the
>>> NAND node.
>>>   
>> Ok, you right.
>> current, the NAND chip is only use one CS (which CE0) for now, what's in
>> the DT is
>>
>> nand@0 {
>>  reg = < 0 >;
>>  ..
>> };
>>
>> so for the multiple chips it would something like this in DT?
>>
>> nand@0 {
>>   reg = < 0 >;
>> };
>>
>> nand@1 {
>>   reg = < 1 >;
>> };
> 
> Yep, that's for 2 single-die chips.
> 
>>
>> or even
>> nand@0 {
>>   reg = < 0 2 >;
>> };
>>
>> nand@1 {
> 
> nand@3 {
> 
>>   reg = < 3 4 >;
>> };
> 
> And this is describing 2 dual-die chips.
> 
>>
>> do we need to encode all the cs information here? not sure if we
>> understand this correctly, but could send out the patch for review..
> 
> Yes, reg should contain an array of controller-side CS lines used to
> select the chip (or a specific die in a chip, the index in the reg
> table being the id of the die).
>
much clear about this, thanks

Yixun

Patch

diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 19a2b283fbbe..b3c17a3ca8f4 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -534,4 +534,12 @@  config MTD_NAND_MTK
 	  Enables support for NAND controller on MTK SoCs.
 	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
 
+config MTD_NAND_MESON
+	tristate "Support for NAND flash controller on Amlogic's Meson SoCs"
+	depends on ARCH_MESON || COMPILE_TEST
+	select COMMON_CLK_REGMAP_MESON
+	select MFD_SYSCON
+	help
+	  Enables support for NAND controller on Amlogic's Meson SoCs.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
index 165b7ef9e9a1..cdf6162f38c3 100644
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -1,5 +1,7 @@ 
 # SPDX-License-Identifier: GPL-2.0
 
+ccflags-$(CONFIG_MTD_NAND_MESON) += -I$(srctree)/drivers/clk/meson
+
 obj-$(CONFIG_MTD_NAND)			+= nand.o
 obj-$(CONFIG_MTD_NAND_ECC)		+= nand_ecc.o
 obj-$(CONFIG_MTD_NAND_BCH)		+= nand_bch.o
@@ -56,6 +58,7 @@  obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
 obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
 obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
 obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
+obj-$(CONFIG_MTD_NAND_MESON)		+= meson_nand.o
 
 nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
 nand-objs += nand_amd.o
diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
new file mode 100644
index 000000000000..28abc3684772
--- /dev/null
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -0,0 +1,1422 @@ 
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Amlogic Meson Nand Flash Controller Driver
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Liang Yang <liang.yang@amlogic.com>
+ */
+
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/module.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include "clk-regmap.h"
+
+#define NFC_REG_CMD		0x00
+#define NFC_REG_CFG		0x04
+#define NFC_REG_DADR		0x08
+#define NFC_REG_IADR		0x0c
+#define NFC_REG_BUF		0x10
+#define NFC_REG_INFO		0x14
+#define NFC_REG_DC		0x18
+#define NFC_REG_ADR		0x1c
+#define NFC_REG_DL		0x20
+#define NFC_REG_DH		0x24
+#define NFC_REG_CADR		0x28
+#define NFC_REG_SADR		0x2c
+#define NFC_REG_PINS		0x30
+#define NFC_REG_VER		0x38
+
+
+#define NFC_CMD_DRD		(0x8 << 14)
+#define NFC_CMD_IDLE		(0xc << 14)
+#define NFC_CMD_DWR		(0x4 << 14)
+#define NFC_CMD_CLE		(0x5 << 14)
+#define NFC_CMD_ALE		(0x6 << 14)
+#define NFC_CMD_ADL		((0 << 16) | (3 << 20))
+#define NFC_CMD_ADH		((1 << 16) | (3 << 20))
+#define NFC_CMD_AIL		((2 << 16) | (3 << 20))
+#define NFC_CMD_AIH		((3 << 16) | (3 << 20))
+#define NFC_CMD_SEED		((8 << 16) | (3 << 20))
+#define NFC_CMD_M2N		((0 << 17) | (2 << 20))
+#define NFC_CMD_N2M		((1 << 17) | (2 << 20))
+#define NFC_CMD_RB		(1 << 20)
+#define NFC_CMD_IO6		((0xb << 10) | (1 << 18))
+
+#define NFC_RB_USED		(1 << 23)
+#define NFC_LARGE_PAGE		(1 << 22)
+#define NFC_RW_OPS		(2 << 20)
+
+#define NAND_TWB_TIME_CYCLE	10
+
+#define CMDRWGEN(cmd_dir, ran, bch, short_mode, page_size, pages)	\
+	(								\
+		(cmd_dir)			|			\
+		((ran) << 19)			|			\
+		((bch) << 14)			| 			\
+		((short_mode) << 13)		|			\
+		(((page_size) & 0x7f) << 6)	|			\
+		((pages) & 0x3f)					\
+	)
+
+#define GENCMDDADDRL(adl, addr)		((adl) | ((addr) & 0xffff))
+#define GENCMDDADDRH(adh, addr)		((adh) | (((addr) >> 16) & 0xffff))
+#define GENCMDIADDRL(ail, addr)		((ail) | ((addr) & 0xffff))
+#define GENCMDIADDRH(aih, addr)		((aih) | (((addr) >> 16) & 0xffff))
+
+#define RB_STA(x)		(1 << (26 + x))
+
+#define ECC_CHECK_RETURN_FF	(-1)
+
+#define NAND_CE0		(0xe << 10)
+#define NAND_CE1		(0xd << 10)
+
+#define DMA_BUSY_TIMEOUT	0x100000
+
+#define MAX_CE_NUM		2
+#define RAN_ENABLE		1
+
+#define SD_EMMC_CLOCK 		0x00
+#define CLK_ALWAYS_ON		BIT(28)
+#define CLK_SELECT_NAND		BIT(31)
+#define CLK_DIV_MASK		GENMASK(5, 0)
+#define CLK_SRC_MASK		GENMASK(7, 6)
+
+#define NFC_CLK_CYCLE		6
+
+/* nand flash controller delay 3 ns */
+#define NFC_DEFAULT_DELAY 3000
+
+#define MAX_ECC_INDEX	10
+
+#define MUX_CLK_NUM_PARENTS 2
+
+struct meson_nfc_info_format {
+	u16 info_bytes;
+	u8 zero_cnt; /* bit0~5 is valid */
+	struct ecc_sta {
+		u8 eccerr_cnt : 6;
+		u8 notused : 1;
+		u8 completed : 1;
+	} ecc;
+	u32 reserved;
+};
+
+#define	PER_INFO_BYTE	(sizeof(struct meson_nfc_info_format))
+
+struct meson_nfc_nand_chip {
+	struct list_head node;
+	struct nand_chip nand;
+	/*
+	 * Then NAND controller support two oob modes:
+	 *  a) 2 user bytes with each ecc page;
+	 *  b) 16 user bytes with 1st ecc page and zero user byte
+	 *      with the other ecc pages.
+	 * when using as mtd mode, the driver prefer to use 2 user bytes mode.
+	 */
+	int user_mode;
+	int rand_mode; /* 0: disable scramble, 1: enable scramble */
+	int bch_mode;
+	int cs;
+
+	u8 *data_buf;
+	u8 *info_buf;
+};
+
+/*
+ * While booting from NAND, a page0 data is needed to tell ROM boot code
+ * to read SPL image, and the ROM boot code need to know which ecc mode
+ * is selected and whether scramble is enabled or not, and so on.
+ *
+ * So when updating SPL image, the driver need to store these informations
+ * into the page0, and SPL image will be loadded into next page - the page1.
+ */
+struct meson_nand_setup {
+	u32 d32;
+	u16 id;
+	u16 max;
+};
+
+struct meson_nand_page0 {
+	struct meson_nand_setup nand_setup;
+	unsigned char page_list[16];
+	unsigned short reserved[32];
+};
+
+struct meson_nand_ecc {
+	int bch;
+	int strength;
+	int parity;
+};
+
+struct meson_nfc_data {
+	struct meson_nand_ecc *ecc;
+	int ecc_num;
+	int bch_mode;
+	int short_bch;
+};
+
+struct meson_nfc_param {
+	int chip_select;
+	int rb_select;
+
+	int page_size;
+	int oob_size;
+	int ecc_size;
+	int ecc_bytes;
+
+	int rand_mode;
+	int oob_mode;
+	int bch_mode;
+	int ecc_step;
+
+	int ecc_max;
+};
+
+struct meson_nfc {
+	struct nand_hw_control controller;
+	struct clk *core_clk;
+	struct clk *device_clk;
+
+	struct device *dev;
+	void __iomem *reg_base;
+	struct regmap *reg_clk;
+
+	struct completion completion;
+	struct list_head chips;
+	struct meson_nfc_data *data;
+	struct meson_nfc_param param;
+	struct meson_nand_page0 *page0;
+
+	u8 *data_buf;
+	u8 *info_buf;
+};
+
+enum {
+	NFC_ECC_NONE	= 0,
+	NFC_ECC_BCH8,		/* bch8 with ecc page size of 512B */
+	NFC_ECC_BCH8_1K,	/* bch8 with ecc page size of 1024B */
+	NFC_ECC_BCH24_1K,
+	NFC_ECC_BCH30_1K,
+	NFC_ECC_BCH40_1K,
+	NFC_ECC_BCH50_1K,
+	NFC_ECC_BCH60_1K,
+
+	/*
+	 * Short mode is special only for page 0 when inplement booting
+	 * from nand, which means a small size(384 bit / 8 = 48 Byte) of
+	 * ecc page is used with a fixed ecc mode. rom code will use short mode
+	 * to read page0 for getting nand parameters such as ecc, scramber, etc.
+	 *
+	 * Example, in GXL SoC, the first page adopt the short mode with
+	 * 60bit ecc, while in AXG SoC, it adopt short mode with 8bit ecc.
+	 */
+	NFC_ECC_BCH_SHORT,
+};
+
+enum {
+	NFC_USER2_OOB_BYTES		= 2,
+	NFC_USER16_OOB_BYTES		= 16,
+};
+
+#define MESON_ECC_DATA(b, s, p)				\
+	{ .bch = (b),	.strength = (s),	.parity = (p) }
+
+struct meson_nand_ecc meson_gxl_ecc[] = {
+	MESON_ECC_DATA(NFC_ECC_NONE, 0, 0),
+	MESON_ECC_DATA(NFC_ECC_BCH8, 8, 14),
+	MESON_ECC_DATA(NFC_ECC_BCH8_1K, 8, 14),
+	MESON_ECC_DATA(NFC_ECC_BCH24_1K, 24, 42),
+	MESON_ECC_DATA(NFC_ECC_BCH30_1K, 30, 54),
+	MESON_ECC_DATA(NFC_ECC_BCH40_1K, 40, 70),
+	MESON_ECC_DATA(NFC_ECC_BCH50_1K, 50, 88),
+	MESON_ECC_DATA(NFC_ECC_BCH60_1K, 60, 106),
+	MESON_ECC_DATA(NFC_ECC_BCH_SHORT, 0xff, 0xff),
+};
+
+struct meson_nand_ecc meson_axg_ecc[] = {
+	MESON_ECC_DATA(NFC_ECC_NONE, 0, 0),
+	MESON_ECC_DATA(NFC_ECC_BCH8, 8, 14),
+	MESON_ECC_DATA(NFC_ECC_BCH8_1K, 8, 14),
+	MESON_ECC_DATA(NFC_ECC_BCH_SHORT, 0xff, 0xff),
+};
+
+static inline struct meson_nfc_nand_chip *to_meson_nand(struct nand_chip *nand)
+{
+	return container_of(nand, struct meson_nfc_nand_chip, nand);
+}
+
+static int meson_nfc_page0_gen(struct meson_nfc *nfc)
+{
+	u32 cmd;
+
+	nfc->page0 = devm_kzalloc(nfc->dev,
+		sizeof(struct meson_nand_page0), GFP_KERNEL);
+	if(!nfc->page0)
+		return -ENOMEM;
+
+	cmd = CMDRWGEN(NFC_CMD_N2M, nfc->param.rand_mode,
+		nfc->param.bch_mode, 0,
+		nfc->param.ecc_size >> 3,
+		nfc->param.ecc_step);
+	cmd |= NFC_RB_USED | NFC_LARGE_PAGE | NFC_RW_OPS;
+	nfc->page0->nand_setup.d32 = cmd;
+
+	return 0;
+}
+
+static void meson_nfc_select_chip(struct mtd_info *mtd, int chip)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+
+	if (chip != meson_chip->cs)
+		return;
+
+	nfc->param.chip_select = chip ? NAND_CE1 : NAND_CE0;
+	nfc->param.rb_select = chip ? NAND_CE1 : NAND_CE0;
+	nfc->param.oob_mode =
+		(meson_chip->user_mode == NFC_USER2_OOB_BYTES) ? 0 : 1;
+	nfc->param.rand_mode = meson_chip->rand_mode;
+	nfc->param.bch_mode = meson_chip->bch_mode;
+
+	nfc->param.ecc_step = mtd->writesize / nand->ecc.size;
+	nfc->param.ecc_size = nand->ecc.size;
+	nfc->param.ecc_bytes =  nand->ecc.bytes;
+	nfc->param.page_size = mtd->writesize;
+	nfc->param.oob_size =  mtd->oobsize;
+	nfc->param.ecc_max = nand->ecc.strength;
+
+	nfc->data_buf = meson_chip->data_buf;
+	nfc->info_buf = meson_chip->info_buf;
+}
+
+static inline void meson_nfc_cmd_idle(struct meson_nfc *nfc, u32 time)
+{
+	writel(nfc->param.chip_select | NFC_CMD_IDLE | (time & 0x3ff),
+			nfc->reg_base + NFC_REG_CMD);
+}
+
+static void meson_nfc_cmd_ctrl(struct mtd_info *mtd,
+					int cmd, unsigned int ctrl)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+
+	if (cmd == NAND_CMD_NONE)
+		return;
+
+	cmd = nfc->param.chip_select | (cmd & 0xff);
+	cmd |= (ctrl & NAND_CLE) ? NFC_CMD_CLE : NFC_CMD_ALE;
+
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+}
+
+static inline void meson_nfc_cmd_seed(struct meson_nfc *nfc, u32 seed)
+{
+	writel(NFC_CMD_SEED | (0xc2 + (seed & 0x7fff)),
+			nfc->reg_base + NFC_REG_CMD);
+}
+
+static void meson_nfc_cmd_m2n(struct meson_nfc *nfc, int raw)
+{
+	u32 cmd, pagesize, pages, shortm = 0;
+	int bch = nfc->param.bch_mode;
+	int len = nfc->param.page_size;
+
+	pagesize = nfc->param.ecc_size;
+
+	if (unlikely(raw)) {
+		bch = NAND_ECC_NONE;
+		len = nfc->param.page_size + nfc->param.oob_size;
+		cmd = NFC_CMD_M2N |
+			(len & 0x3fff) | (nfc->param.rand_mode << 19);
+		writel(cmd, nfc->reg_base + NFC_REG_CMD);
+		return;
+	}
+
+	if (unlikely(bch == NFC_ECC_BCH_SHORT)) {
+		bch = nfc->data->short_bch;
+		pagesize = 384 >> 3;
+		pages = len / nfc->param.ecc_size;
+		memcpy(nfc->data_buf,
+			nfc->page0, sizeof(struct meson_nand_page0));
+		shortm = 1;
+	} else
+		pages = len / nfc->param.ecc_size;
+
+	cmd = CMDRWGEN(NFC_CMD_M2N,
+		nfc->param.rand_mode, bch, shortm, pagesize, pages);
+
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+}
+
+static void meson_nfc_cmd_n2m(struct meson_nfc *nfc, int raw)
+{
+	u32 cmd, pagesize, pages, shortm = 0;
+	int bch = nfc->param.bch_mode;
+	int len = nfc->param.page_size;
+
+	pagesize = nfc->param.ecc_size;
+
+	if (unlikely(raw)) {
+		bch = NAND_ECC_NONE;
+		len = nfc->param.page_size + nfc->param.oob_size;
+		cmd = (len & 0x3fff) | (nfc->param.rand_mode << 19) |
+			NFC_CMD_N2M;
+		writel(cmd, nfc->reg_base + NFC_REG_CMD);
+		return;
+	}
+
+	if (unlikely(bch == NFC_ECC_BCH_SHORT)) {
+		bch = nfc->data->short_bch;
+		pagesize = 384 >> 3;
+		pages = len / nfc->param.ecc_size;
+		shortm = 1;
+	} else
+		pages = len / nfc->param.ecc_size;
+
+	cmd = CMDRWGEN(NFC_CMD_N2M,
+		nfc->param.rand_mode, bch, shortm, pagesize, pages);
+
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+}
+
+static int meson_nfc_wait_cmd_finish(struct meson_nfc *nfc,
+					unsigned int timeout_ms)
+{
+	u32 cmd_size = 0;
+	int ret;
+
+	/* wait cmd fifo is empty */
+	ret = readl_poll_timeout(nfc->reg_base + NFC_REG_CMD,
+				cmd_size,
+				!((cmd_size >> 22) & 0x1f),
+				10, timeout_ms * 1000);
+	if (ret)
+		dev_err(nfc->dev, "wait for empty cmd FIFO time out\n");
+
+	return ret;
+}
+
+static int meson_nfc_wait_dma_finish(struct meson_nfc *nfc)
+{
+	meson_nfc_cmd_idle(nfc, 0);
+	meson_nfc_cmd_idle(nfc, 0);
+
+	return meson_nfc_wait_cmd_finish(nfc, DMA_BUSY_TIMEOUT);
+}
+
+static inline struct meson_nfc_info_format *nfc_info_ptr(struct meson_nfc *nfc,
+	int index)
+{
+	return (struct meson_nfc_info_format *) &nfc->info_buf[index * 8];
+}
+
+static u8 *meson_nfc_oob_ptr(struct meson_nfc *nfc, int i)
+{
+	int x, len;
+	int ecc_bytes = nfc->param.ecc_bytes, temp = nfc->param.ecc_size;
+
+	x = i ? 16 : 0;
+	len = (nfc->param.oob_mode) ? (temp * (i + 1) + ecc_bytes * i + x) :
+				(temp * (i + 1) + (ecc_bytes + 2) * i);
+
+	return nfc->data_buf + len;
+}
+
+static u8 *meson_nfc_data_ptr(struct meson_nfc *nfc, int i)
+{
+	int len, x;
+	int temp = nfc->param.ecc_size + nfc->param.ecc_bytes;
+
+	x = i ? 16 : 0;
+	len = nfc->param.oob_mode ? (temp * i + x) : (temp + 2) * i;
+
+	return nfc->data_buf + len;
+}
+
+static void meson_nfc_prase_data_oob(struct meson_nfc *nfc, u8 *buf, u8 *oob)
+{
+	int i, oob_len = 0;
+	u8 *dsrc, *osrc;
+
+	for (i = 0; i < nfc->param.ecc_step; i++) {
+		if (buf) {
+			dsrc = meson_nfc_data_ptr(nfc, i);
+			memcpy(buf, dsrc, nfc->param.ecc_size);
+			buf += nfc->param.ecc_size;
+		}
+
+		if (nfc->param.oob_mode)
+			oob_len = (i) ? nfc->param.ecc_bytes :
+						nfc->param.ecc_bytes + 16;
+		else
+			oob_len = nfc->param.ecc_bytes + 2;
+
+		osrc = meson_nfc_oob_ptr(nfc, i);
+		memcpy(oob, osrc, oob_len);
+		oob += oob_len;
+	}
+}
+
+static void meson_nfc_format_data_oob(struct meson_nfc *nfc,
+						const u8 *buf, u8 *oob)
+{
+	int i, oob_len = 0;
+	u8 *dsrc, *osrc;
+
+	for (i = 0; i < nfc->param.ecc_step; i++) {
+		if (buf) {
+			dsrc = meson_nfc_data_ptr(nfc, i);
+			memcpy(dsrc, buf, nfc->param.ecc_size);
+			buf += nfc->param.ecc_size;
+		}
+
+		if (nfc->param.oob_mode)
+			oob_len = i ? nfc->param.ecc_bytes :
+						nfc->param.ecc_bytes + 16;
+		else
+			oob_len = nfc->param.ecc_bytes + 2;
+
+		osrc = meson_nfc_oob_ptr(nfc, i);
+		memcpy(osrc, oob, oob_len);
+		oob += oob_len;
+	}
+}
+
+static int meson_nfc_queue_rb(struct meson_nfc *nfc)
+{
+	u32 cmd, cfg;
+	int ret = 0;
+
+	init_completion(&nfc->completion);
+
+	cfg = readl(nfc->reg_base + NFC_REG_CFG);
+	cfg |= (1 << 21);
+	writel(cfg, nfc->reg_base + NFC_REG_CFG);
+
+	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
+	cmd = nfc->param.chip_select | NFC_CMD_CLE | (NAND_CMD_STATUS & 0xff);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
+
+	cmd = NFC_CMD_RB | NFC_CMD_IO6 | (1 << 16) | (0x18 & 0x1f);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+	meson_nfc_cmd_idle(nfc, 2);
+
+	ret = wait_for_completion_timeout(&nfc->completion,
+					msecs_to_jiffies(1000));
+	if (ret == 0) {
+		dev_err(nfc->dev, "wait nand irq timeout\n");
+		ret = -1;
+	}
+
+	return ret;
+}
+
+static void meson_nfc_set_user_byte(struct mtd_info *mtd,
+					struct nand_chip *chip, u8 *oob_buf)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	struct meson_nfc_info_format *info;
+	int i, count;
+
+	if (nfc->param.oob_mode) {
+		memcpy(nfc->info_buf, oob_buf, 16);
+		return;
+	}
+
+	for (i = 0, count = 0; i < chip->ecc.steps; i++, count += 2) {
+		info = nfc_info_ptr(nfc, i);
+		info->info_bytes =
+			oob_buf[count] | (oob_buf[count + 1] << 8);
+	}
+}
+
+static void meson_nfc_get_user_byte(struct mtd_info *mtd,
+					struct nand_chip *chip, u8 *oob_buf)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	struct meson_nfc_info_format *info;
+	int i, count;
+
+	if (nfc->param.oob_mode) {
+		memcpy(oob_buf,  nfc->info_buf, 16);
+		return;
+	}
+
+	for (i = 0, count = 0; i < chip->ecc.steps; i++, count += 2) {
+		info = nfc_info_ptr(nfc, i);
+		oob_buf[count] = info->info_bytes & 0xff;
+		oob_buf[count + 1] = (info->info_bytes >> 8) & 0xff;
+	}
+}
+
+static int meson_nfc_ecc_correct(struct mtd_info *mtd,
+						struct nand_chip *chip)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	struct meson_nfc_info_format *info;
+	u32 bitflips = 0, i;
+	u8 zero_cnt;
+
+	for (i = 0; i < nfc->param.ecc_step; i++) {
+		info = nfc_info_ptr(nfc, i);
+		if (info->ecc.eccerr_cnt == 0x3f) {
+			zero_cnt = info->zero_cnt & 0x3f;
+			if (nfc->param.rand_mode
+				&& (zero_cnt < nfc->param.ecc_max))
+				return ECC_CHECK_RETURN_FF;
+			mtd->ecc_stats.failed++;
+			continue;
+		}
+		mtd->ecc_stats.corrected += info->ecc.eccerr_cnt;
+		bitflips = max_t(u32, bitflips, info->ecc.eccerr_cnt);
+	}
+
+	return bitflips;
+}
+
+static inline u8 meson_nfc_read_byte(struct mtd_info *mtd)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	u32 cmd;
+
+	cmd = nfc->param.chip_select | NFC_CMD_DRD | 0;
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	meson_nfc_cmd_idle(nfc, 0);
+	meson_nfc_cmd_idle(nfc, 0);
+
+	meson_nfc_wait_cmd_finish(nfc, 1000);
+
+	return readb(nfc->reg_base + NFC_REG_BUF);
+}
+
+static void meson_nfc_read_buf(struct mtd_info *mtd, u8 *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		buf[i] = meson_nfc_read_byte(mtd);
+}
+
+static void meson_nfc_write_byte(struct mtd_info *mtd, u8 byte)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(mtd_to_nand(mtd));
+	u32 cmd;
+
+	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
+
+	cmd = nfc->param.chip_select | NFC_CMD_DWR | (byte & 0xff);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	meson_nfc_cmd_idle(nfc, NAND_TWB_TIME_CYCLE);
+	meson_nfc_cmd_idle(nfc, 0);
+
+	meson_nfc_wait_cmd_finish(nfc, 1000);
+}
+
+static void meson_nfc_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		meson_nfc_write_byte(mtd, buf[i]);
+}
+
+static int meson_nfc_write_page_sub(struct mtd_info *mtd,
+		struct nand_chip *chip, const u8 *buf, int page, int raw)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	dma_addr_t daddr, iaddr;
+	u32 cmd;
+	int ret;
+
+	nand_prog_page_begin_op(chip, page, 0, NULL, 0);
+
+	daddr = dma_map_single(nfc->dev, (void *)nfc->data_buf,
+			mtd->writesize + mtd->oobsize, DMA_TO_DEVICE);
+	ret = dma_mapping_error(nfc->dev, daddr);
+	if (ret) {
+		dev_err(nfc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	iaddr = dma_map_single(nfc->dev, (void *)nfc->info_buf,
+			nfc->param.ecc_step * PER_INFO_BYTE, DMA_TO_DEVICE);
+	ret = dma_mapping_error(nfc->dev, iaddr);
+	if (ret) {
+		dev_err(nfc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	cmd = GENCMDDADDRL(NFC_CMD_ADL, daddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+	cmd = GENCMDDADDRH(NFC_CMD_ADH, daddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	cmd = GENCMDIADDRL(NFC_CMD_AIL, iaddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+	cmd = GENCMDIADDRH(NFC_CMD_AIH, iaddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	meson_nfc_cmd_seed(nfc, page);
+
+	meson_nfc_cmd_m2n(nfc, raw);
+
+	ret = meson_nfc_wait_dma_finish(nfc);
+
+	dma_unmap_single(nfc->dev, daddr,
+			mtd->writesize + mtd->oobsize, DMA_TO_DEVICE);
+	dma_unmap_single(nfc->dev, iaddr,
+			nfc->param.ecc_step * PER_INFO_BYTE, DMA_TO_DEVICE);
+
+	return nand_prog_page_end_op(chip);
+}
+
+static int meson_nfc_write_page_raw(struct mtd_info *mtd,
+	struct nand_chip *chip, const u8 *buf, int oob_required, int page)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	u8 *oob_buf = chip->oob_poi;
+
+	meson_nfc_format_data_oob(nfc, buf, oob_buf);
+
+	return meson_nfc_write_page_sub(mtd, chip, nfc->data_buf, page, 1);
+}
+
+static int meson_nfc_write_page_hwecc(struct mtd_info *mtd,
+				    struct nand_chip *chip, const u8 *buf,
+				    int oob_required, int page)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	u8 *oob_buf = chip->oob_poi;
+
+	memcpy(nfc->data_buf, buf, mtd->writesize);
+	meson_nfc_set_user_byte(mtd, chip, oob_buf);
+
+	return meson_nfc_write_page_sub(mtd, chip, nfc->data_buf, page, 0);
+}
+
+static void meson_nfc_check_ecc_pages_valid(struct meson_nfc *nfc, int raw)
+{
+	struct meson_nfc_info_format *info;
+	int neccpages, i;
+
+	neccpages = raw ? 1 : nfc->param.ecc_step;
+
+	for (i = 0; i < neccpages; i++) {
+		info = nfc_info_ptr(nfc, neccpages - 1);
+		if (info->ecc.completed == 0)
+			dev_err(nfc->dev, "seems eccpage is invalid\n");
+	}
+}
+
+static int meson_nfc_read_page_sub(struct mtd_info *mtd,
+	struct nand_chip *chip, const u8 *buf, int page, int raw)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	dma_addr_t daddr, iaddr;
+	u32 cmd;
+	int ret;
+
+	nand_read_page_op(chip, page, 0, NULL, 0);
+
+	daddr = dma_map_single(nfc->dev, nfc->data_buf,
+			mtd->writesize + mtd->oobsize, DMA_FROM_DEVICE);
+	ret = dma_mapping_error(nfc->dev, daddr);
+	if (ret) {
+		dev_err(nfc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	iaddr = dma_map_single(nfc->dev, nfc->info_buf,
+			nfc->param.ecc_step * PER_INFO_BYTE, DMA_FROM_DEVICE);
+	ret = dma_mapping_error(nfc->dev, iaddr);
+	if (ret) {
+		dev_err(nfc->dev, "dma mapping error\n");
+		return -EINVAL;
+	}
+
+	cmd = GENCMDDADDRL(NFC_CMD_ADL, daddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+	cmd = GENCMDDADDRH(NFC_CMD_ADH, daddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	cmd = GENCMDIADDRL(NFC_CMD_AIL, iaddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+	cmd = GENCMDIADDRH(NFC_CMD_AIH, iaddr);
+	writel(cmd, nfc->reg_base + NFC_REG_CMD);
+
+	meson_nfc_cmd_seed(nfc, page);
+
+	meson_nfc_cmd_n2m(nfc, raw);
+
+	ret = meson_nfc_wait_dma_finish(nfc);
+
+	meson_nfc_queue_rb(nfc);
+
+	meson_nfc_check_ecc_pages_valid(nfc, raw);
+
+	dma_unmap_single(nfc->dev, daddr,
+			mtd->writesize + mtd->oobsize, DMA_FROM_DEVICE);
+	dma_unmap_single(nfc->dev, iaddr,
+			nfc->param.ecc_step * PER_INFO_BYTE, DMA_FROM_DEVICE);
+
+	return ret;
+}
+
+static int meson_nfc_read_page_raw(struct mtd_info *mtd,
+	struct nand_chip *chip, u8 *buf, int oob_required, int page)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	u8 *oob_buf = chip->oob_poi;
+	int ret;
+
+	ret = meson_nfc_read_page_sub(mtd, chip, nfc->data_buf, page, 1);
+	if (ret)
+		return ret;
+
+	meson_nfc_prase_data_oob(nfc, buf, oob_buf);
+
+	return 0;
+}
+
+static int meson_nfc_read_page_hwecc(struct mtd_info *mtd,
+	struct nand_chip *chip, u8 *buf, int oob_required, int page)
+{
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	u8 *oob_buf = chip->oob_poi;
+	int ret;
+
+	ret = meson_nfc_read_page_sub(mtd, chip, nfc->data_buf, page, 0);
+	if (ret)
+		return ret;
+
+	meson_nfc_get_user_byte(mtd, chip, oob_buf);
+
+	ret = meson_nfc_ecc_correct(mtd, chip);
+	if (ret == ECC_CHECK_RETURN_FF) {
+		if (buf)
+			memset(buf, 0xff, mtd->writesize);
+
+		memset(oob_buf, 0xff, mtd->oobsize);
+		return 0;
+	}
+	if (buf && (buf != nfc->data_buf))
+		memcpy(buf, nfc->data_buf, mtd->writesize);
+
+	return ret;
+}
+
+static int meson_nfc_read_oob_raw(struct mtd_info *mtd,
+				struct nand_chip *chip, int page)
+{
+	return meson_nfc_read_page_raw(mtd, chip, NULL, 1, page);
+}
+
+static int meson_nfc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
+				int page)
+{
+	return meson_nfc_read_page_hwecc(mtd, chip, NULL, 1, page);
+}
+
+static int meson_ooblayout_ecc(struct mtd_info *mtd, int section,
+				  struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+	int free_oob;
+
+	if (section > chip->ecc.steps)
+		return -ERANGE;
+
+	free_oob = nfc->param.oob_mode ? 16 : (chip->ecc.steps * 2);
+	oobregion->offset = section * chip->ecc.bytes + free_oob;
+	oobregion->length = chip->ecc.bytes;
+
+	return 0;
+}
+
+static int meson_ooblayout_free(struct mtd_info *mtd, int section,
+				   struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct meson_nfc *nfc = nand_get_controller_data(chip);
+
+	if (section > chip->ecc.steps)
+		return -ERANGE;
+
+	oobregion->offset = 0;
+	oobregion->length = nfc->param.oob_mode ? 16 : (chip->ecc.steps * 2);
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops meson_ooblayout_ops = {
+	.ecc = meson_ooblayout_ecc,
+	.free = meson_ooblayout_free,
+};
+
+static int meson_nfc_ecc_init(struct device *dev, struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	struct meson_nand_ecc *meson_ecc = nfc->data->ecc;
+	int num = nfc->data->ecc_num;
+	int nsectors, i, bytes;
+
+	/* support only ecc hw mode */
+	if (nand->ecc.mode != NAND_ECC_HW) {
+		dev_err(dev, "ecc.mode not supported\n");
+		return -EINVAL;
+	}
+
+	if (!nand->ecc.size || !nand->ecc.strength) {
+		/* use datasheet requirements */
+		nand->ecc.strength = nand->ecc_strength_ds;
+		nand->ecc.size = nand->ecc_step_ds;
+	}
+
+	if (nand->ecc.options & NAND_ECC_MAXIMIZE) {
+		nand->ecc.size = 1024;
+		nsectors = mtd->writesize / nand->ecc.size;
+
+		/* Reserve 2 bytes for each ecc page */
+		if (meson_chip->user_mode == NFC_USER2_OOB_BYTES)
+			bytes = mtd->oobsize - 2 * nsectors;
+		else
+			bytes = mtd->oobsize - 16;
+
+		bytes /= nsectors;
+
+		/* and bytes has to be even. */
+		if (bytes % 2)
+			bytes--;
+
+		nand->ecc.strength = bytes * 8 / fls(8 * nand->ecc.size);
+	} else {
+		if (nand->ecc.strength > meson_ecc[num - 1].strength) {
+			dev_err(dev, "not support ecc strength\n");
+			return -EINVAL;
+		}
+	}
+
+	for (i = 0; i < num; i++) {
+		if ((meson_ecc[i].strength == 0xff)
+			|| (nand->ecc.strength < meson_ecc[i].strength))
+			break;
+	}
+
+	if (!i) {
+		nand->ecc.strength = 0;
+	} else {
+		nand->ecc.strength = meson_ecc[i - 1].strength;
+		nand->ecc.bytes = meson_ecc[i - 1].parity;
+	}
+
+	meson_chip->bch_mode = meson_ecc[i - 1].bch;
+
+	if (nand->ecc.size != 512 && nand->ecc.size != 1024)
+		return -EINVAL;
+
+	nsectors = mtd->writesize / nand->ecc.size;
+	bytes =(meson_chip->user_mode == NFC_USER2_OOB_BYTES) ? nsectors * 2 : 16;
+	if (mtd->oobsize < (nand->ecc.bytes * nsectors + bytes))
+		return -EINVAL;
+
+	return 0;
+}
+
+static const char * sd_emmc_ext_clk0_parent_names[MUX_CLK_NUM_PARENTS];
+
+static struct clk_regmap sd_emmc_c_ext_clk0_sel = {
+	.data = &(struct clk_regmap_mux_data){
+		.offset = SD_EMMC_CLOCK,
+		.mask = 0x3,
+		.shift = 6,
+	},
+	.hw.init = &(struct clk_init_data) {
+		.name = "sd_emmc_c_nand_clk_mux",
+		.ops = &clk_regmap_mux_ops,
+		.parent_names = sd_emmc_ext_clk0_parent_names,
+		.num_parents = ARRAY_SIZE(sd_emmc_ext_clk0_parent_names),
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static struct clk_regmap sd_emmc_c_ext_clk0_div = {
+	.data = &(struct clk_regmap_div_data){
+		.offset = SD_EMMC_CLOCK,
+		.shift = 0,
+		.width = 6,
+		.flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
+	},
+	.hw.init = &(struct clk_init_data) {
+		.name = "sd_emmc_c_nand_clk_div",
+		.ops = &clk_regmap_divider_ops,
+		.parent_names = (const char *[]){ "sd_emmc_c_nand_clk_mux" },
+		.num_parents = 1,
+		.flags = CLK_SET_RATE_PARENT,
+	},
+};
+
+static int meson_nfc_clk_init(struct meson_nfc *nfc)
+{
+	struct clk_regmap *mux = &sd_emmc_c_ext_clk0_sel;
+	struct clk_regmap *div = &sd_emmc_c_ext_clk0_div;
+	struct clk *clk;
+	int i, ret;
+
+	/* request core clock */
+	nfc->core_clk = devm_clk_get(nfc->dev, "core");
+	if (IS_ERR(nfc->core_clk)) {
+		dev_err(nfc->dev, "failed to get core clk\n");
+		return PTR_ERR(nfc->core_clk);
+	}
+
+	/* init SD_EMMC_CLOCK to sane defaults w/min clock rate */
+	regmap_update_bits(nfc->reg_clk, 0,
+			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK,
+			CLK_SELECT_NAND | CLK_ALWAYS_ON | CLK_DIV_MASK);
+
+	/* get the mux parents */
+	for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
+		char name[16];
+
+		snprintf(name, sizeof(name), "clkin%d", i);
+		clk = devm_clk_get(nfc->dev, name);
+		if (IS_ERR(clk)) {
+			if (clk != ERR_PTR(-EPROBE_DEFER))
+				dev_err(nfc->dev, "Missing clock %s\n", name);
+			return PTR_ERR(clk);
+		}
+
+		sd_emmc_ext_clk0_parent_names[i] = __clk_get_name(clk);
+	}
+
+	mux->map = nfc->reg_clk;
+	clk = devm_clk_register(nfc->dev, &mux->hw);
+	if (WARN_ON(IS_ERR(clk)))
+		return PTR_ERR(clk);
+
+	div->map = nfc->reg_clk;
+	nfc->device_clk = devm_clk_register(nfc->dev, &div->hw);
+	if (WARN_ON(IS_ERR(nfc->device_clk)))
+		return PTR_ERR(nfc->device_clk);
+
+	ret = clk_prepare_enable(nfc->core_clk);
+	if (ret) {
+		dev_err(nfc->dev, "failed to enable core clk\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(nfc->device_clk);
+	if (ret) {
+		dev_err(nfc->dev, "failed to enable device clk\n");
+		clk_disable_unprepare(nfc->core_clk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void meson_nfc_disable_clk(struct meson_nfc *nfc)
+{
+	clk_disable_unprepare(nfc->device_clk);
+	clk_disable_unprepare(nfc->core_clk);
+}
+
+static int meson_nfc_buffer_init(struct mtd_info *mtd)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	struct device *dev = nfc->dev;
+	int info_bytes, page_bytes;
+	int nsectors;
+
+	nsectors = mtd->writesize / nand->ecc.size;
+	info_bytes = nsectors * PER_INFO_BYTE;
+	page_bytes = mtd->writesize + mtd->oobsize;
+
+	if ((meson_chip->data_buf) && (meson_chip->info_buf))
+		return 0;
+
+	meson_chip->data_buf = devm_kzalloc(dev, page_bytes, GFP_KERNEL);
+	if (!meson_chip->data_buf)
+		return  -ENOMEM;
+
+	meson_chip->info_buf = devm_kzalloc(dev, info_bytes, GFP_KERNEL);
+	if (!meson_chip->info_buf)
+		return  -ENOMEM;
+
+	return 0;
+}
+
+static int meson_nfc_calc_set_timing(struct meson_nfc *nfc,
+				int rc_min, int rea_max, int rhoh_min)
+{
+	int div, bt_min, bt_max, bus_timing;
+	int ret;
+
+	div = DIV_ROUND_UP((rc_min / 1000), NFC_CLK_CYCLE);
+	ret = clk_set_rate(nfc->device_clk, 1000000000 / div);
+	if (ret) {
+		dev_err(nfc->dev, "failed to set nand clock rate\n");
+		return ret;
+	}
+
+	bt_min = (rea_max + NFC_DEFAULT_DELAY) / div;
+	bt_max = (NFC_DEFAULT_DELAY + rhoh_min + rc_min / 2) / div;
+
+	bt_min = DIV_ROUND_UP(bt_min, 1000);
+	bt_max = DIV_ROUND_UP(bt_max, 1000);
+
+	if (bt_max < bt_min)
+		return -EINVAL;
+
+	bus_timing = (bt_min + bt_max) / 2 + 1;
+
+	writel((1 << 21), nfc->reg_base + NFC_REG_CFG);
+	writel((NFC_CLK_CYCLE - 1) | (bus_timing << 5),
+				nfc->reg_base + NFC_REG_CFG);
+
+	writel((1 << 31), nfc->reg_base + NFC_REG_CMD);
+
+	return 0;
+}
+
+static int meson_nfc_setup_data_interface(struct mtd_info *mtd, int csline,
+				const struct nand_data_interface *conf)
+{
+	struct nand_chip *nand = mtd_to_nand(mtd);
+	struct meson_nfc *nfc = nand_get_controller_data(nand);
+	const struct nand_sdr_timings *timings;
+
+	timings = nand_get_sdr_timings(conf);
+	if (IS_ERR(timings))
+		return -ENOTSUPP;
+
+	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+		return 0;
+
+	meson_nfc_calc_set_timing(nfc, timings->tRC_min,
+				timings->tREA_max, timings->tRHOH_min);
+
+	return 0;
+}
+
+static int meson_nfc_get_nand_chip_dts(struct meson_nfc *nfc,
+		struct meson_nfc_nand_chip *chip, struct device_node *np)
+{
+	struct device *dev = nfc->dev;
+
+	if (of_property_read_u32(np, "reg", &chip->cs)) {
+		dev_err(dev, "can not get ce number\n");
+		return -EINVAL;
+	}
+
+	if (chip->cs > MAX_CE_NUM) {
+		dev_err(dev, "ce number is beyond\n");
+		return -EINVAL;
+	}
+
+	if (of_property_read_u32(np, "meson-nand-user-mode", &chip->user_mode)) {
+		dev_err(dev, "can not get user oob mode\n");
+		return -EINVAL;
+	}
+
+	if ((chip->user_mode != NFC_USER2_OOB_BYTES)
+			|| (chip->user_mode != NFC_USER16_OOB_BYTES))
+		chip->user_mode = NFC_USER2_OOB_BYTES;
+
+	if (of_property_read_u32(np, "meson-nand-ran-mode", &chip->rand_mode)) {
+		dev_err(dev, "can not get scramble mode\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int meson_nfc_nand_chip_init(struct device *dev, struct meson_nfc *nfc,
+				  struct device_node *np)
+{
+	struct meson_nfc_nand_chip *chip;
+	struct nand_chip *nand;
+	struct mtd_info *mtd;
+	int ret;
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	ret = meson_nfc_get_nand_chip_dts(nfc, chip, np);
+	if (ret)
+		return ret;
+
+	nand = &chip->nand;
+	nand_set_flash_node(nand, np);
+	nand_set_controller_data(nand, nfc);
+
+	nand->options |= NAND_USE_BOUNCE_BUFFER;
+	nand->select_chip = meson_nfc_select_chip;
+	nand->write_byte = meson_nfc_write_byte;
+	nand->write_buf = meson_nfc_write_buf;
+	nand->read_byte = meson_nfc_read_byte;
+	nand->read_buf = meson_nfc_read_buf;
+	nand->cmd_ctrl = meson_nfc_cmd_ctrl;
+	nand->setup_data_interface = meson_nfc_setup_data_interface;
+
+	nand->chip_delay = 200;
+	nand->ecc.mode = NAND_ECC_HW;
+
+	nand->ecc.write_page_raw = meson_nfc_write_page_raw;
+	nand->ecc.write_page = meson_nfc_write_page_hwecc;
+	nand->ecc.write_oob_raw = nand_write_oob_std;
+	nand->ecc.write_oob = nand_write_oob_std;
+
+	nand->ecc.read_page_raw = meson_nfc_read_page_raw;
+	nand->ecc.read_page = meson_nfc_read_page_hwecc;
+	nand->ecc.read_oob_raw = meson_nfc_read_oob_raw;
+	nand->ecc.read_oob = meson_nfc_read_oob;
+
+	mtd = nand_to_mtd(nand);
+	mtd->owner = THIS_MODULE;
+	mtd->dev.parent = dev;
+	mtd->name = devm_kasprintf(nfc->dev, GFP_KERNEL,
+				   "%s:nand", dev_name(dev));
+	if (!mtd->name) {
+		dev_err(nfc->dev, "Failed to allocate mtd->name\n");
+		return -ENOMEM;
+	}
+
+	mtd_set_ooblayout(mtd, &meson_ooblayout_ops);
+
+	ret = nand_scan_ident(mtd, 1, NULL);
+	if (ret) {
+		dev_err(dev, "failed to can ident\n");
+		return -ENODEV;
+	}
+
+	/* store bbt magic in page, cause OOB is not protected */
+	if (nand->bbt_options & NAND_BBT_USE_FLASH)
+		nand->bbt_options |= NAND_BBT_NO_OOB;
+
+	nand->options |= NAND_NO_SUBPAGE_WRITE;
+
+	ret = meson_nfc_ecc_init(dev, mtd);
+	if (ret) {
+		dev_err(dev, "failed to ecc init\n");
+		return -EINVAL;
+	}
+
+	if (nand->options & NAND_BUSWIDTH_16) {
+		dev_err(dev, "16bits buswidth not supported");
+		return -EINVAL;
+	}
+
+	ret = meson_nfc_buffer_init(mtd);
+	if (ret)
+		return -ENOMEM;
+
+	ret = nand_scan_tail(mtd);
+	if (ret)
+		return -ENODEV;
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret) {
+		dev_err(dev, "failed to register mtd device: %d\n", ret);
+		nand_release(mtd);
+		return ret;
+	}
+
+	list_add_tail(&chip->node, &nfc->chips);
+
+	return 0;
+}
+
+static int meson_nfc_nand_chips_init(struct device *dev, struct meson_nfc *nfc)
+{
+	struct device_node *np = dev->of_node;
+	struct device_node *nand_np;
+	int ret;
+
+	for_each_child_of_node(np, nand_np) {
+		ret = meson_nfc_nand_chip_init(dev, nfc, nand_np);
+		if (ret) {
+			of_node_put(nand_np);
+			return ret;
+		}
+	}
+	return 0;
+}
+
+static irqreturn_t meson_nfc_irq(int irq, void *id)
+{
+	struct meson_nfc *nfc = id;
+	u32 cfg;
+
+	cfg = readl(nfc->reg_base + NFC_REG_CFG);
+	cfg |= (1 << 21);
+	writel(cfg, nfc->reg_base + NFC_REG_CFG);
+
+	complete(&nfc->completion);
+	return IRQ_HANDLED;
+}
+
+static const struct meson_nfc_data meson_gxl_data = {
+	.short_bch	= NFC_ECC_BCH60_1K,
+	.ecc		= meson_gxl_ecc,
+	.ecc_num	= ARRAY_SIZE(meson_gxl_ecc),
+};
+
+static const struct meson_nfc_data meson_axg_data = {
+	.short_bch	= NFC_ECC_BCH8_1K,
+	.ecc		= meson_axg_ecc,
+	.ecc_num	= ARRAY_SIZE(meson_axg_ecc),
+};
+
+static const struct of_device_id meson_nfc_id_table[] = {
+	{
+		.compatible = "amlogic,meson-gxl-nfc",
+		.data = &meson_gxl_data,
+	}, {
+		.compatible = "amlogic,meson-axg-nfc",
+		.data = &meson_axg_data,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, meson_nfc_id_table);
+
+static int meson_nfc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct meson_nfc *nfc;
+	struct resource *res;
+	const struct of_device_id *of_nfc_id;
+	int ret, irq;
+
+	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
+	if (!nfc)
+		return -ENOMEM;
+
+	of_nfc_id = of_match_device(meson_nfc_id_table, &pdev->dev);
+	if (!of_nfc_id)
+		return -ENODEV;
+
+	nfc->data = (struct meson_nfc_data *)of_nfc_id->data;
+
+	spin_lock_init(&nfc->controller.lock);
+	init_waitqueue_head(&nfc->controller.wq);
+	INIT_LIST_HEAD(&nfc->chips);
+
+	nfc->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Failed to nfc reg resource\n");
+		return -EINVAL;
+	}
+
+	nfc->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(nfc->reg_base)) {
+		dev_err(dev, "Failed to lookup nfi reg base\n");
+		return PTR_ERR(nfc->reg_base);
+	}
+
+	nfc->reg_clk = syscon_regmap_lookup_by_phandle(dev->of_node,
+							"amlogic,mmc-syscon");
+	if (IS_ERR(nfc->reg_clk)) {
+		dev_err(dev, "Failed to lookup clock base\n");
+		return PTR_ERR(nfc->reg_clk);
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "no nfi irq resource\n");
+		return -EINVAL;
+	}
+
+	ret = meson_nfc_clk_init(nfc);
+	if (ret) {
+		dev_err(dev, "failed to initialize nand clk\n");
+		goto err_clk;
+	}
+
+	ret = devm_request_irq(dev, irq, meson_nfc_irq, 0, dev_name(dev), nfc);
+	if (ret) {
+		dev_err(dev, "failed to request nfi irq\n");
+		ret = -EINVAL;
+		goto err_clk;
+	}
+
+	ret = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dev, "failed to set dma mask\n");
+		goto err_clk;
+	}
+
+	platform_set_drvdata(pdev, nfc);
+
+	ret = meson_nfc_nand_chips_init(dev, nfc);
+	if (ret) {
+		dev_err(dev, "failed to init nand chips\n");
+		goto err_clk;
+	}
+
+	meson_nfc_page0_gen(nfc);
+	return 0;
+
+err_clk:
+	clk_disable_unprepare(nfc->device_clk);
+	clk_disable_unprepare(nfc->core_clk);
+
+	return ret;
+}
+
+static int meson_nfc_remove(struct platform_device *pdev)
+{
+	struct meson_nfc *nfc = platform_get_drvdata(pdev);
+	struct meson_nfc_nand_chip *chip;
+
+	while (!list_empty(&nfc->chips)) {
+		chip = list_first_entry(&nfc->chips, struct meson_nfc_nand_chip,
+					node);
+		nand_release(nand_to_mtd(&chip->nand));
+		list_del(&chip->node);
+	}
+
+	meson_nfc_disable_clk(nfc);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver meson_nfc_driver = {
+	.probe  = meson_nfc_probe,
+	.remove = meson_nfc_remove,
+	.driver = {
+		.name  = "meson_nand",
+		.of_match_table = meson_nfc_id_table,
+	},
+};
+
+module_platform_driver(meson_nfc_driver);
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_AUTHOR("Liang Yang <liang.yang@amlogic.com>");
+MODULE_DESCRIPTION("Amlogic's Meson NAND Flash Controller driver");