[v5,0/5] add Amlogic A1 clock controller driver

add support for Amlogic A1 clock driver, the clock includes 
three parts: peripheral clocks, pll clocks, CPU clocks.
sys pll and CPU clocks will be sent in next patch.

Changes since v4 at [5]:
- change yaml GPL
- drop meson-eeclk.c patch, add probe function in each driver
- add CLK_IS_CRITICAL for sys_clk clock, drop the flag for sys_a and sys_b
- add new parm for pll, add protection for rst parm
- drop flag for a1_fixed_pll
- remove the same comment for fclk_div, add "refer to"
- add critical flag for a1_sys_clk
- remove rtc table
- rename a1_dspa_en_dspa and a1_dspb_en_dspb
- remove useless comment

Changes since v3 at [3]:
-fix reparenting orphan failed, it depends on jerome's patch [4]
-fix changelist in v3 about reparenting orphan
-remove the dts patch 

Changes since v2 at [2]:
-add probe function for A1
-seperate the clock driver into two patch
-change some clock flags and ops
-add support for a1 PLL ops
-add A1 clock node
-fix reparenting orphan clock failed, registering xtal_fixpll
 and xtal_hifipll after the provider registration, it is not
 a best way.

Changes since v1 at [1]:
-place A1 config alphabetically
-add actual reason for RO ops, CLK_IS_CRITICAL, CLK_IGNORE_UNUSED
-separate the driver into two driver: peripheral and pll driver
-delete CLK_IGNORE_UNUSED flag for pwm b/c/d/e/f clock, dsp clock
-delete the change in Kconfig.platforms, address to Kevin alone
-remove the useless comments
-modify the meson pll driver to support A1 PLLs

[1] https://lkml.kernel.org/r/1569411888-98116-1-git-send-email-jian.hu@amlogic.com
[2] https://lkml.kernel.org/r/1571382865-41978-1-git-send-email-jian.hu@amlogic.com
[3] https://lkml.kernel.org/r/20191129144605.182774-1-jian.hu@amlogic.com
[4] https://lkml.kernel.org/r/20191203080805.104628-1-jbrunet@baylibre.com
[5] https://lkml.kernel.org/r/20191206074052.15557-1-jian.hu@amlogic.com

Jian Hu (5):
  dt-bindings: clock: meson: add A1 PLL clock controller bindings
  clk: meson: add support for A1 PLL clock ops
  clk: meson: a1: add support for Amlogic A1 PLL clock driver
  dt-bindings: clock: meson: add A1 peripheral clock controller bindings
  clk: meson: a1: add support for Amlogic A1 Peripheral clock driver

 .../bindings/clock/amlogic,a1-clkc.yaml       |   67 +
 .../bindings/clock/amlogic,a1-pll-clkc.yaml   |   54 +
 drivers/clk/meson/Kconfig                     |   18 +
 drivers/clk/meson/Makefile                    |    2 +
 drivers/clk/meson/a1-pll.c                    |  374 +++
 drivers/clk/meson/a1-pll.h                    |   56 +
 drivers/clk/meson/a1.c                        | 2263 +++++++++++++++++
 drivers/clk/meson/a1.h                        |  120 +
 drivers/clk/meson/clk-pll.c                   |   40 +-
 drivers/clk/meson/clk-pll.h                   |    2 +
 include/dt-bindings/clock/a1-clkc.h           |   98 +
 include/dt-bindings/clock/a1-pll-clkc.h       |   16 +
 12 files changed, 3105 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/amlogic,a1-clkc.yaml
 create mode 100644 Documentation/devicetree/bindings/clock/amlogic,a1-pll-clkc.yaml
 create mode 100644 drivers/clk/meson/a1-pll.c
 create mode 100644 drivers/clk/meson/a1-pll.h
 create mode 100644 drivers/clk/meson/a1.c
 create mode 100644 drivers/clk/meson/a1.h
 create mode 100644 include/dt-bindings/clock/a1-clkc.h
 create mode 100644 include/dt-bindings/clock/a1-pll-clkc.h

Hi Jian,

On Fri, Dec 27, 2019 at 10:46 AM Jian Hu <jian.hu@amlogic.com> wrote:
[...]
> @@ -294,9 +298,12 @@ static int meson_clk_pll_is_enabled(struct clk_hw *hw)
>  {
>         struct clk_regmap *clk = to_clk_regmap(hw);
>         struct meson_clk_pll_data *pll = meson_clk_pll_data(clk);
> +       int ret = 0;
>
> -       if (meson_parm_read(clk->map, &pll->rst) ||
> -           !meson_parm_read(clk->map, &pll->en) ||
> +       if (MESON_PARM_APPLICABLE(&pll->rst))
> +               ret = meson_parm_read(clk->map, &pll->rst);
> +
> +       if (ret || !meson_parm_read(clk->map, &pll->en) ||
>             !meson_parm_read(clk->map, &pll->l))
>                 return 0;
I had to read this part twice to understand what it's doing because I
misunderstood what "ret" is used for (I thought that some "return ret"
is missing)
my proposal to make it easier to read:
...
if (MESON_PARM_APPLICABLE(&pll->rst) &&
    meson_parm_read(clk->map, &pll->rst))
  return 0;

if (!meson_parm_read(clk->map, &pll->en) ||
    !meson_parm_read(clk->map, &pll->l))
                 return 0;
...

please let me know what you think about this

> @@ -321,6 +328,23 @@ static int meson_clk_pll_enable(struct clk_hw *hw)
>         /* do nothing if the PLL is already enabled */
>         if (clk_hw_is_enabled(hw))
>                 return 0;
> +       /*
> +        * Compared with the previous SoCs, self-adaption module current
> +        * is newly added for A1, keep the new power-on sequence to enable the
> +        * PLL.
> +        */
> +       if (MESON_PARM_APPLICABLE(&pll->current_en)) {
> +               /* Enable the pll */
> +               meson_parm_write(clk->map, &pll->en, 1);
> +               udelay(10);
> +               /* Enable the pll self-adaption module current */
> +               meson_parm_write(clk->map, &pll->current_en, 1);
> +               udelay(40);
> +               /* Enable lock detect module */
> +               meson_parm_write(clk->map, &pll->l_detect, 1);
> +               meson_parm_write(clk->map, &pll->l_detect, 0);
> +               goto out;
> +       }
in all other functions you are skipping the pll->rst register by
checking for MESON_PARM_APPLICABLE(&pll->rst)
I like that because it's a pattern which is easy to follow

do you think we can make this part consistent with that?
I'm thinking of something like this (not compile-tested and I dropped
all comments, just so you get the idea):
...
if (MESON_PARM_APPLICABLE(&pll->rst)
  meson_parm_write(clk->map, &pll->rst, 1);

meson_parm_write(clk->map, &pll->en, 1);

if (MESON_PARM_APPLICABLE(&pll->rst))
  meson_parm_write(clk->map, &pll->rst, 0);

if (MESON_PARM_APPLICABLE(&pll->current_en))
  meson_parm_write(clk->map, &pll->current_en, 1);

if (MESON_PARM_APPLICABLE(&pll->l_detect)) {
  meson_parm_write(clk->map, &pll->l_detect, 1);
  meson_parm_write(clk->map, &pll->l_detect, 0);
}

if (meson_clk_pll_wait_lock(hw))
...

I see two (and a half) benefits here:
- if there's a PLL with neither the pll->current_en nor the pll->rst
registers then you get support for this implementation for free
- the if (MESON_PARM_APPLICABLE(...)) pattern is already used in the
driver, but only for one register (in your example when
MESON_PARM_APPLICABLE(&pll->current_en) exists you also modify the
pll->l_detect register, which I did not expect)
- only counts half: no use of "goto", which in my opinion makes it
very easy to read (just read from top to bottom, checking each "if")


Martin

Hi Martin

Thanks for your review

On 2019/12/28 0:53, Martin Blumenstingl wrote:
> Hi Jian,
> 
> On Fri, Dec 27, 2019 at 10:46 AM Jian Hu <jian.hu@amlogic.com> wrote:
> [...]
>> @@ -294,9 +298,12 @@ static int meson_clk_pll_is_enabled(struct clk_hw *hw)
>>   {
>>          struct clk_regmap *clk = to_clk_regmap(hw);
>>          struct meson_clk_pll_data *pll = meson_clk_pll_data(clk);
>> +       int ret = 0;
>>
>> -       if (meson_parm_read(clk->map, &pll->rst) ||
>> -           !meson_parm_read(clk->map, &pll->en) ||
>> +       if (MESON_PARM_APPLICABLE(&pll->rst))
>> +               ret = meson_parm_read(clk->map, &pll->rst);
>> +
>> +       if (ret || !meson_parm_read(clk->map, &pll->en) ||
>>              !meson_parm_read(clk->map, &pll->l))
>>                  return 0;
> I had to read this part twice to understand what it's doing because I
> misunderstood what "ret" is used for (I thought that some "return ret"
> is missing)
> my proposal to make it easier to read:
> ...
> if (MESON_PARM_APPLICABLE(&pll->rst) &&
>      meson_parm_read(clk->map, &pll->rst))
>    return 0;
> 
> if (!meson_parm_read(clk->map, &pll->en) ||
>      !meson_parm_read(clk->map, &pll->l))
>                   return 0;
> ...
> 
> please let me know what you think about this
I was intended to use 'ret' to store the return value of pll->rst.

If pll->rst exists, it will get it. Otherwise, the ret will be zero.

Your proposal is a good way for it. I will use it.
> 
>> @@ -321,6 +328,23 @@ static int meson_clk_pll_enable(struct clk_hw *hw)
>>          /* do nothing if the PLL is already enabled */
>>          if (clk_hw_is_enabled(hw))
>>                  return 0;
>> +       /*
>> +        * Compared with the previous SoCs, self-adaption module current
>> +        * is newly added for A1, keep the new power-on sequence to enable the
>> +        * PLL.
>> +        */
>> +       if (MESON_PARM_APPLICABLE(&pll->current_en)) {
>> +               /* Enable the pll */
>> +               meson_parm_write(clk->map, &pll->en, 1);
>> +               udelay(10);
>> +               /* Enable the pll self-adaption module current */
>> +               meson_parm_write(clk->map, &pll->current_en, 1);
>> +               udelay(40);
>> +               /* Enable lock detect module */
>> +               meson_parm_write(clk->map, &pll->l_detect, 1);
>> +               meson_parm_write(clk->map, &pll->l_detect, 0);
>> +               goto out;
>> +       }
> in all other functions you are skipping the pll->rst register by
> checking for MESON_PARM_APPLICABLE(&pll->rst)
> I like that because it's a pattern which is easy to follow
> 
> do you think we can make this part consistent with that?
> I'm thinking of something like this (not compile-tested and I dropped
> all comments, just so you get the idea):
It is a good idea. I will test it.
> ...
> if (MESON_PARM_APPLICABLE(&pll->rst)
>    meson_parm_write(clk->map, &pll->rst, 1);
> 
> meson_parm_write(clk->map, &pll->en, 1);
> 
> if (MESON_PARM_APPLICABLE(&pll->rst))
>    meson_parm_write(clk->map, &pll->rst, 0);
> 
> if (MESON_PARM_APPLICABLE(&pll->current_en))
>    meson_parm_write(clk->map, &pll->current_en, 1);
> 
> if (MESON_PARM_APPLICABLE(&pll->l_detect)) {
>    meson_parm_write(clk->map, &pll->l_detect, 1);
>    meson_parm_write(clk->map, &pll->l_detect, 0);
> }
> 
> if (meson_clk_pll_wait_lock(hw))
> ...
> 
> I see two (and a half) benefits here:
> - if there's a PLL with neither the pll->current_en nor the pll->rst
> registers then you get support for this implementation for free
> - the if (MESON_PARM_APPLICABLE(...)) pattern is already used in the
> driver, but only for one register (in your example when
> MESON_PARM_APPLICABLE(&pll->current_en) exists you also modify the
> pll->l_detect register, which I did not expect)
> - only counts half: no use of "goto", which in my opinion makes it
> very easy to read (just read from top to bottom, checking each "if")
> 
I see, I will verify it.
> 
> Martin
> 
> .
>