[v7,1/5] mtd: nand: vf610_nfc: Freescale NFC for VF610, MPC5125 and others

This driver supports Freescale NFC (NAND flash controller) found on
Vybrid (VF610), MPC5125, MCF54418 and Kinetis K70. The driver has
been tested on 8-bit and 16-bit NAND interface and supports ONFI
parameter page reading.

Limitations:
- DMA and pipelining not used
- Pages larger than 2k are not supported
- No hardware ECC

The driver has only been tested on Vybrid SoC VF610 and VF500.

Some paths have been hand-optimized and evaluated by measurements
made using mtd_speedtest.ko on a 100MB MTD partition.

Colibri VF50
    eb write     %   eb read     %   page write      %   page read     %
rel/opt     5175           11537                4560             11039
opt         5164 -0.21     11420 -1.01          4737 +3.88       10918 -1.10
none        5113 -1.20     11352 -1.60          4490 -1.54       10865 -1.58

Colibri VF61
    eb write     %   eb read     %   page write      %   page read     %
rel/opt     5766           13096                5459             12846
opt         5883 +2.03     13064 -0.24          5561 +1.87       12802 -0.34
none        5701 -1.13     12980 -0.89          5488 +0.53       12735 -0.86

rel = using readl_relaxed/writel_relaxed in optimized paths
opt = hand-optimized by combining multiple accesses into one read/write

The measurements have not been statistically verfied, hence use them
with care. The author came to the conclusion that using the relaxed
variants of readl/writel are not worth the additional code.

Signed-off-by: Bill Pringlemeir <bpringlemeir@nbsps.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 MAINTAINERS                  |   6 +
 drivers/mtd/nand/Kconfig     |   9 +
 drivers/mtd/nand/Makefile    |   1 +
 drivers/mtd/nand/vf610_nfc.c | 640 +++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 656 insertions(+)
 create mode 100644 drivers/mtd/nand/vf610_nfc.c

Hi Alexey,

[converted back to plain text]
On 2015-08-01 00:54, Alexey Klimov wrote: 
> just two small questions. 
> 
> On Jul 24, 2015 4:20 PM, "Stefan Agner" <stefan@agner.ch> wrote:
>> 
>> This driver supports Freescale NFC (NAND flash controller) found on
>> Vybrid (VF610), MPC5125, MCF54418 and Kinetis K70. The driver has
>> been tested on 8-bit and 16-bit NAND interface and supports ONFI
>> parameter page reading.
>> 
>> Limitations:
>> - DMA and pipelining not used
>> - Pages larger than 2k are not supported
>> - No hardware ECC
>> 
>> The driver has only been tested on Vybrid SoC VF610 and VF500.
>> 
>> Some paths have been hand-optimized and evaluated by measurements
>> made using mtd_speedtest.ko on a 100MB MTD partition.
>> 
>> Colibri VF50
>> eb write % eb read % page write % page read %
>> rel/opt 5175 11537 4560 11039
>> opt 5164 -0.21 11420 -1.01 4737 +3.88 10918 -1.10
>> none 5113 -1.20 11352 -1.60 4490 -1.54 10865 -1.58
>> 
>> Colibri VF61
>> eb write % eb read % page write % page read %
>> rel/opt 5766 13096 5459 12846
>> opt 5883 +2.03 13064 -0.24 5561 +1.87 12802 -0.34
>> none 5701 -1.13 12980 -0.89 5488 +0.53 12735 -0.86
>> 
>> rel = using readl_relaxed/writel_relaxed in optimized paths
>> opt = hand-optimized by combining multiple accesses into one read/write
>> 
>> The measurements have not been statistically verfied, hence use them
>> with care. The author came to the conclusion that using the relaxed
>> variants of readl/writel are not worth the additional code.
>> 
>> Signed-off-by: Bill Pringlemeir <bpringlemeir@nbsps.com>
>> Signed-off-by: Stefan Agner <stefan@agner.ch>
>> ---
>> MAINTAINERS | 6 +
>> drivers/mtd/nand/Kconfig | 9 +
>> drivers/mtd/nand/Makefile | 1 +
>> drivers/mtd/nand/vf610_nfc.c | 640 +++++++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 656 insertions(+)
>> create mode 100644 drivers/mtd/nand/vf610_nfc.c
>> 
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 9567329..59975c7 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10835,6 +10835,12 @@ S: Maintained
>> F: Documentation/fb/uvesafb.txt
>> F: drivers/video/fbdev/uvesafb.*
>> 
>> +VF610 NAND DRIVER
>> +M: Stefan Agner <stefan@agner.ch>
>> +L: linux-mtd@lists.infradead.org
>> +S: Supported
>> +F: drivers/mtd/nand/vf610_nfc.c
>> +
>> VFAT/FAT/MSDOS FILESYSTEM
>> M: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
>> S: Maintained
>> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
>> index 5b2806a..8550b14 100644
>> --- a/drivers/mtd/nand/Kconfig
>> +++ b/drivers/mtd/nand/Kconfig
>> @@ -463,6 +463,15 @@ config MTD_NAND_MPC5121_NFC
>> This enables the driver for the NAND flash controller on the
>> MPC5121 SoC.
>> 
>> +config MTD_NAND_VF610_NFC
>> + tristate "Support for Freescale NFC for VF610/MPC5125"
>> + depends on (SOC_VF610 || COMPILE_TEST)
>> + help
>> + Enables support for NAND Flash Controller on some Freescale
>> + processors like the VF610, MPC5125, MCF54418 or Kinetis K70.
>> + The driver supports a maximum 2k page size. The driver
>> + currently does not support hardware ECC.
>> +
>> config MTD_NAND_MXC
>> tristate "MXC NAND support"
>> depends on ARCH_MXC
>> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
>> index 1f897ec..a490af8 100644
>> --- a/drivers/mtd/nand/Makefile
>> +++ b/drivers/mtd/nand/Makefile
>> @@ -45,6 +45,7 @@ obj-$(CONFIG_MTD_NAND_SOCRATES) += socrates_nand.o
>> obj-$(CONFIG_MTD_NAND_TXX9NDFMC) += txx9ndfmc.o
>> obj-$(CONFIG_MTD_NAND_NUC900) += nuc900_nand.o
>> obj-$(CONFIG_MTD_NAND_MPC5121_NFC) += mpc5121_nfc.o
>> +obj-$(CONFIG_MTD_NAND_VF610_NFC) += vf610_nfc.o
>> obj-$(CONFIG_MTD_NAND_RICOH) += r852.o
>> obj-$(CONFIG_MTD_NAND_JZ4740) += jz4740_nand.o
>> obj-$(CONFIG_MTD_NAND_GPMI_NAND) += gpmi-nand/
>> diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
>> new file mode 100644
>> index 0000000..0da500e
>> --- /dev/null
>> +++ b/drivers/mtd/nand/vf610_nfc.c
>> @@ -0,0 +1,640 @@
>> +/*
>> + * Copyright 2009-2015 Freescale Semiconductor, Inc. and others
>> + *
>> + * Description: MPC5125, VF610, MCF54418 and Kinetis K70 Nand driver.
>> + * Jason ported to M54418TWR and MVFA5 (VF610).
>> + * Authors: Stefan Agner <stefan.agner@toradex.com>
>> + * Bill Pringlemeir <bpringlemeir@nbsps.com>
>> + * Shaohui Xie <b21989@freescale.com>
>> + * Jason Jin <Jason.jin@freescale.com>
>> + *
>> + * Based on original driver mpc5121_nfc.c.
>> + *
>> + * This is free software; you can redistribute it and/or modify it
>> + * under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * Limitations:
>> + * - Untested on MPC5125 and M54418.
>> + * - DMA not used.
>> + * - 2K pages or less.
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +#include <linux/init.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/mtd/mtd.h>
>> +#include <linux/mtd/nand.h>
>> +#include <linux/mtd/partitions.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/slab.h>
>> +#include <linux/of_mtd.h>
>> +
>> +#define DRV_NAME "vf610_nfc"
>> +
>> +/* Register Offsets */
>> +#define NFC_FLASH_CMD1 0x3F00
>> +#define NFC_FLASH_CMD2 0x3F04
>> +#define NFC_COL_ADDR 0x3F08
>> +#define NFC_ROW_ADDR 0x3F0c
>> +#define NFC_ROW_ADDR_INC 0x3F14
>> +#define NFC_FLASH_STATUS1 0x3F18
>> +#define NFC_FLASH_STATUS2 0x3F1c
>> +#define NFC_CACHE_SWAP 0x3F28
>> +#define NFC_SECTOR_SIZE 0x3F2c
>> +#define NFC_FLASH_CONFIG 0x3F30
>> +#define NFC_IRQ_STATUS 0x3F38
>> +
>> +/* Addresses for NFC MAIN RAM BUFFER areas */
>> +#define NFC_MAIN_AREA(n) ((n) * 0x1000)
>> +
>> +#define PAGE_2K 0x0800
>> +#define OOB_64 0x0040
>> +
>> +/*
>> + * NFC_CMD2[CODE] values. See section:
>> + * - 31.4.7 Flash Command Code Description, Vybrid manual
>> + * - 23.8.6 Flash Command Sequencer, MPC5125 manual
>> + *
>> + * Briefly these are bitmasks of controller cycles.
>> + */
>> +#define READ_PAGE_CMD_CODE 0x7EE0
>> +#define READ_ONFI_PARAM_CMD_CODE 0x4860
>> +#define PROGRAM_PAGE_CMD_CODE 0x7FC0
>> +#define ERASE_CMD_CODE 0x4EC0
>> +#define READ_ID_CMD_CODE 0x4804
>> +#define RESET_CMD_CODE 0x4040
>> +#define STATUS_READ_CMD_CODE 0x4068
>> +
>> +/* NFC ECC mode define */
>> +#define ECC_BYPASS 0
>> +
>> +/*** Register Mask and bit definitions */
>> +
>> +/* NFC_FLASH_CMD1 Field */
>> +#define CMD_BYTE2_MASK 0xFF000000
>> +#define CMD_BYTE2_SHIFT 24
>> +
>> +/* NFC_FLASH_CM2 Field */
>> +#define CMD_BYTE1_MASK 0xFF000000
>> +#define CMD_BYTE1_SHIFT 24
>> +#define CMD_CODE_MASK 0x00FFFF00
>> +#define CMD_CODE_SHIFT 8
>> +#define BUFNO_MASK 0x00000006
>> +#define BUFNO_SHIFT 1
>> +#define START_BIT (1<<0)
>> +
>> +/* NFC_COL_ADDR Field */
>> +#define COL_ADDR_MASK 0x0000FFFF
>> +#define COL_ADDR_SHIFT 0
>> +
>> +/* NFC_ROW_ADDR Field */
>> +#define ROW_ADDR_MASK 0x00FFFFFF
>> +#define ROW_ADDR_SHIFT 0
>> +#define ROW_ADDR_CHIP_SEL_RB_MASK 0xF0000000
>> +#define ROW_ADDR_CHIP_SEL_RB_SHIFT 28
>> +#define ROW_ADDR_CHIP_SEL_MASK 0x0F000000
>> +#define ROW_ADDR_CHIP_SEL_SHIFT 24
>> +
>> +/* NFC_FLASH_STATUS2 Field */
>> +#define STATUS_BYTE1_MASK 0x000000FF
>> +
>> +/* NFC_FLASH_CONFIG Field */
>> +#define CONFIG_ECC_SRAM_REQ_BIT (1<<21)
>> +#define CONFIG_DMA_REQ_BIT (1<<20)
>> +#define CONFIG_ECC_MODE_MASK 0x000E0000
>> +#define CONFIG_ECC_MODE_SHIFT 17
>> +#define CONFIG_FAST_FLASH_BIT (1<<16)
>> +#define CONFIG_16BIT (1<<7)
>> +#define CONFIG_BOOT_MODE_BIT (1<<6)
>> +#define CONFIG_ADDR_AUTO_INCR_BIT (1<<5)
>> +#define CONFIG_BUFNO_AUTO_INCR_BIT (1<<4) 
> 
> Can you consider using BIT() macro here and below? 
> 

Ok, will do.

>> +#define CONFIG_PAGE_CNT_MASK 0xF
>> +#define CONFIG_PAGE_CNT_SHIFT 0
>> +
>> +/* NFC_IRQ_STATUS Field */
>> +#define IDLE_IRQ_BIT (1<<29)
>> +#define IDLE_EN_BIT (1<<20)
>> +#define CMD_DONE_CLEAR_BIT (1<<18)
>> +#define IDLE_CLEAR_BIT (1<<17)
>> +
>> +struct vf610_nfc {
>> + struct mtd_info mtd;
>> + struct nand_chip chip;
>> + struct device *dev;
>> + void __iomem *regs;
>> + struct completion cmd_done;
>> + uint buf_offset;
>> + int page_sz;
>> + /* Status and ID are in alternate locations. */
>> + int alt_buf;
>> +#define ALT_BUF_ID 1
>> +#define ALT_BUF_STAT 2
>> +#define ALT_BUF_ONFI 3
>> + struct clk *clk;
>> +};
>> +
>> +#define mtd_to_nfc(_mtd) container_of(_mtd, struct vf610_nfc, mtd)
>> +
>> +static inline u32 vf610_nfc_read(struct vf610_nfc *nfc, uint reg)
>> +{
>> + return readl(nfc->regs + reg);
>> +}
>> +
>> +static inline void vf610_nfc_write(struct vf610_nfc *nfc, uint reg, u32 val)
>> +{
>> + writel(val, nfc->regs + reg);
>> +}
>> +
>> +static inline void vf610_nfc_set(struct vf610_nfc *nfc, uint reg, u32 bits)
>> +{
>> + vf610_nfc_write(nfc, reg, vf610_nfc_read(nfc, reg) | bits);
>> +}
>> +
>> +static inline void vf610_nfc_clear(struct vf610_nfc *nfc, uint reg, u32 bits)
>> +{
>> + vf610_nfc_write(nfc, reg, vf610_nfc_read(nfc, reg) & ~bits);
>> +}
>> +
>> +static inline void vf610_nfc_set_field(struct vf610_nfc *nfc, u32 reg,
>> + u32 mask, u32 shift, u32 val)
>> +{
>> + vf610_nfc_write(nfc, reg,
>> + (vf610_nfc_read(nfc, reg) & (~mask)) | val << shift);
>> +}
>> +
>> +static inline void vf610_nfc_memcpy(void *dst, const void *src, size_t n)
>> +{
>> + /*
>> + * Use this accessor for the internal SRAM buffers. On the ARM
>> + * Freescale Vybrid SoC it's known that the driver can treat
>> + * the SRAM buffer as if it's memory. Other platform might need
>> + * to treat the buffers differently.
>> + *
>> + * For the time being, use memcpy
>> + */
>> + memcpy(dst, src, n);
>> +}
>> +
>> +/* Clear flags for upcoming command */
>> +static inline void vf610_nfc_clear_status(struct vf610_nfc *nfc)
>> +{
>> + u32 tmp = vf610_nfc_read(nfc, NFC_IRQ_STATUS);
>> +
>> + tmp |= CMD_DONE_CLEAR_BIT | IDLE_CLEAR_BIT;
>> + vf610_nfc_write(nfc, NFC_IRQ_STATUS, tmp);
>> +}
>> +
>> +static inline void vf610_nfc_done(struct vf610_nfc *nfc)
>> +{
>> + unsigned long timeout = msecs_to_jiffies(100);
>> +
>> + /*
>> + * Barrier is needed after this write. This write need
>> + * to be done before reading the next register the first
>> + * time.
>> + * vf610_nfc_set implicates such a barrier by using writel
>> + * to write to the register.
>> + */
>> + vf610_nfc_set(nfc, NFC_IRQ_STATUS, IDLE_EN_BIT);
>> + vf610_nfc_set(nfc, NFC_FLASH_CMD2, START_BIT);
>> +
>> + if (!(vf610_nfc_read(nfc, NFC_IRQ_STATUS) & IDLE_IRQ_BIT)) {
>> + if (!wait_for_completion_timeout(&nfc->cmd_done, timeout))
>> + dev_warn(nfc->dev, "Timeout while waiting for BUSY.\n");
>> + }
>> + vf610_nfc_clear_status(nfc);
>> +}
>> +
>> +static u8 vf610_nfc_get_id(struct vf610_nfc *nfc, int col)
>> +{
>> + u32 flash_id;
>> +
>> + if (col < 4) {
>> + flash_id = vf610_nfc_read(nfc, NFC_FLASH_STATUS1);
>> + flash_id >>= (3 - col) * 8;
>> + } else {
>> + flash_id = vf610_nfc_read(nfc, NFC_FLASH_STATUS2);
>> + flash_id >>= 24;
>> + }
>> +
>> + return flash_id & 0xff;
>> +}
>> +
>> +static u8 vf610_nfc_get_status(struct vf610_nfc *nfc)
>> +{
>> + return vf610_nfc_read(nfc, NFC_FLASH_STATUS2) & STATUS_BYTE1_MASK;
>> +}
>> +
>> +static void vf610_nfc_send_command(struct vf610_nfc *nfc, u32 cmd_byte1,
>> + u32 cmd_code)
>> +{
>> + u32 tmp;
>> +
>> + vf610_nfc_clear_status(nfc);
>> +
>> + tmp = vf610_nfc_read(nfc, NFC_FLASH_CMD2);
>> + tmp &= ~(CMD_BYTE1_MASK | CMD_CODE_MASK | BUFNO_MASK);
>> + tmp |= cmd_byte1 << CMD_BYTE1_SHIFT;
>> + tmp |= cmd_code << CMD_CODE_SHIFT;
>> + vf610_nfc_write(nfc, NFC_FLASH_CMD2, tmp);
>> +}
>> +
>> +static void vf610_nfc_send_commands(struct vf610_nfc *nfc, u32 cmd_byte1,
>> + u32 cmd_byte2, u32 cmd_code)
>> +{
>> + u32 tmp;
>> +
>> + vf610_nfc_send_command(nfc, cmd_byte1, cmd_code);
>> +
>> + tmp = vf610_nfc_read(nfc, NFC_FLASH_CMD1);
>> + tmp &= ~CMD_BYTE2_MASK;
>> + tmp |= cmd_byte2 << CMD_BYTE2_SHIFT;
>> + vf610_nfc_write(nfc, NFC_FLASH_CMD1, tmp);
>> +}
>> +
>> +static irqreturn_t vf610_nfc_irq(int irq, void *data)
>> +{
>> + struct mtd_info *mtd = data;
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> +
>> + vf610_nfc_clear(nfc, NFC_IRQ_STATUS, IDLE_EN_BIT);
>> + complete(&nfc->cmd_done);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static void vf610_nfc_addr_cycle(struct vf610_nfc *nfc, int column, int page)
>> +{
>> + if (column != -1) {
>> + if (nfc->chip.options & NAND_BUSWIDTH_16)
>> + column = column / 2;
>> + vf610_nfc_set_field(nfc, NFC_COL_ADDR, COL_ADDR_MASK,
>> + COL_ADDR_SHIFT, column);
>> + }
>> + if (page != -1)
>> + vf610_nfc_set_field(nfc, NFC_ROW_ADDR, ROW_ADDR_MASK,
>> + ROW_ADDR_SHIFT, page);
>> +}
>> +
>> +static inline void vf610_nfc_transfer_size(struct vf610_nfc *nfc, int size)
>> +{
>> + vf610_nfc_write(nfc, NFC_SECTOR_SIZE, size);
>> +}
>> +
>> +static void vf610_nfc_command(struct mtd_info *mtd, unsigned command,
>> + int column, int page)
>> +{
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> + int page_sz = nfc->chip.options & NAND_BUSWIDTH_16 ? 1 : 0;
>> +
>> + nfc->buf_offset = max(column, 0);
>> + nfc->alt_buf = 0;
>> +
>> + switch (command) {
>> + case NAND_CMD_SEQIN:
>> + /* Use valid column/page from preread... */
>> + vf610_nfc_addr_cycle(nfc, column, page);
>> + /*
>> + * SEQIN => data => PAGEPROG sequence is done by the controller
>> + * hence we do not need to issue the command here...
>> + */
>> + return;
>> + case NAND_CMD_PAGEPROG:
>> + page_sz += mtd->writesize + mtd->oobsize;
>> + vf610_nfc_transfer_size(nfc, page_sz);
>> + vf610_nfc_send_commands(nfc, NAND_CMD_SEQIN,
>> + command, PROGRAM_PAGE_CMD_CODE);
>> + break;
>> +
>> + case NAND_CMD_RESET:
>> + vf610_nfc_transfer_size(nfc, 0);
>> + vf610_nfc_send_command(nfc, command, RESET_CMD_CODE);
>> + break;
>> +
>> + case NAND_CMD_READOOB:
>> + page_sz += mtd->oobsize;
>> + column = mtd->writesize;
>> + vf610_nfc_transfer_size(nfc, page_sz);
>> + vf610_nfc_send_commands(nfc, NAND_CMD_READ0,
>> + NAND_CMD_READSTART, READ_PAGE_CMD_CODE);
>> + vf610_nfc_addr_cycle(nfc, column, page);
>> + break;
>> +
>> + case NAND_CMD_READ0:
>> + page_sz += mtd->writesize + mtd->oobsize;
>> + vf610_nfc_transfer_size(nfc, page_sz);
>> + vf610_nfc_send_commands(nfc, NAND_CMD_READ0,
>> + NAND_CMD_READSTART, READ_PAGE_CMD_CODE);
>> + vf610_nfc_addr_cycle(nfc, column, page);
>> + break;
>> +
>> + case NAND_CMD_PARAM:
>> + nfc->alt_buf = ALT_BUF_ONFI;
>> + vf610_nfc_transfer_size(nfc, 768);
>> + vf610_nfc_send_command(nfc, command, READ_ONFI_PARAM_CMD_CODE);
>> + vf610_nfc_set_field(nfc, NFC_ROW_ADDR, ROW_ADDR_MASK,
>> + ROW_ADDR_SHIFT, column);
>> + break;
>> +
>> + case NAND_CMD_ERASE1:
>> + vf610_nfc_transfer_size(nfc, 0);
>> + vf610_nfc_send_commands(nfc, command,
>> + NAND_CMD_ERASE2, ERASE_CMD_CODE);
>> + vf610_nfc_addr_cycle(nfc, column, page);
>> + break;
>> +
>> + case NAND_CMD_READID:
>> + nfc->alt_buf = ALT_BUF_ID;
>> + nfc->buf_offset = 0;
>> + vf610_nfc_transfer_size(nfc, 0);
>> + vf610_nfc_send_command(nfc, command, READ_ID_CMD_CODE);
>> + vf610_nfc_set_field(nfc, NFC_ROW_ADDR, ROW_ADDR_MASK,
>> + ROW_ADDR_SHIFT, column);
>> + break;
>> +
>> + case NAND_CMD_STATUS:
>> + nfc->alt_buf = ALT_BUF_STAT;
>> + vf610_nfc_transfer_size(nfc, 0);
>> + vf610_nfc_send_command(nfc, command, STATUS_READ_CMD_CODE);
>> + break;
>> + default:
>> + return;
>> + }
>> +
>> + vf610_nfc_done(nfc);
>> +}
>> +
>> +static void vf610_nfc_read_buf(struct mtd_info *mtd, u_char *buf, int len)
>> +{
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> + uint c = nfc->buf_offset;
>> +
>> + /* Alternate buffers are only supported through read_byte */
>> + WARN_ON(nfc->alt_buf);
>> +
>> + vf610_nfc_memcpy(buf, nfc->regs + NFC_MAIN_AREA(0) + c, len);
>> +
>> + nfc->buf_offset += len;
>> +}
>> +
>> +static void vf610_nfc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
>> + int len)
>> +{
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> + uint c = nfc->buf_offset;
>> + uint l;
>> +
>> + l = min_t(uint, len, mtd->writesize + mtd->oobsize - c);
>> + vf610_nfc_memcpy(nfc->regs + NFC_MAIN_AREA(0) + c, buf, l);
>> +
>> + nfc->buf_offset += l;
>> +}
>> +
>> +static uint8_t vf610_nfc_read_byte(struct mtd_info *mtd)
>> +{
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> + u8 tmp;
>> + uint c = nfc->buf_offset;
>> +
>> + switch (nfc->alt_buf) {
>> + case ALT_BUF_ID:
>> + tmp = vf610_nfc_get_id(nfc, c);
>> + break;
>> + case ALT_BUF_STAT:
>> + tmp = vf610_nfc_get_status(nfc);
>> + break;
>> +#ifdef __LITTLE_ENDIAN
>> + case ALT_BUF_ONFI:
>> + /* Reverse byte since the controller uses big endianness */
>> + c = nfc->buf_offset ^ 0x3;
>> + tmp = *((u8 *)(nfc->regs + NFC_MAIN_AREA(0) + c)); 
> 
> What do you think about fallthrough here? Instead of tmp = ... and break. 
> 

Hm, true that would work as well.

>> + break;
>> +#endif
>> + default:
>> + tmp = *((u8 *)(nfc->regs + NFC_MAIN_AREA(0) + c));
>> + break;
>> + }
>> + nfc->buf_offset++;
>> + return tmp;
>> +}
>> +
>> +static u16 vf610_nfc_read_word(struct mtd_info *mtd)
>> +{
>> + u16 tmp;
>> +
>> + vf610_nfc_read_buf(mtd, (u_char *)&tmp, sizeof(tmp));
>> + return tmp;
>> +}
>> +
>> +/* If not provided, upper layers apply a fixed delay. */
>> +static int vf610_nfc_dev_ready(struct mtd_info *mtd)
>> +{
>> + /* NFC handles R/B internally; always ready. */
>> + return 1;
>> +}
>> +
>> +/*
>> + * This function supports Vybrid only (MPC5125 would have full RB and four CS)
>> + */
>> +static void vf610_nfc_select_chip(struct mtd_info *mtd, int chip)
>> +{
>> +#ifdef CONFIG_SOC_VF610
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> + u32 tmp = vf610_nfc_read(nfc, NFC_ROW_ADDR);
>> +
>> + tmp &= ~(ROW_ADDR_CHIP_SEL_RB_MASK | ROW_ADDR_CHIP_SEL_MASK);
>> + tmp |= 1 << ROW_ADDR_CHIP_SEL_RB_SHIFT;
>> +
>> + if (chip == 0)
>> + tmp |= 1 << ROW_ADDR_CHIP_SEL_SHIFT;
>> + else if (chip == 1)
>> + tmp |= 2 << ROW_ADDR_CHIP_SEL_SHIFT;
>> +
>> + vf610_nfc_write(nfc, NFC_ROW_ADDR, tmp);
>> +#endif
>> +}
>> +
>> +static const struct of_device_id vf610_nfc_dt_ids[] = {
>> + { .compatible = "fsl,vf610-nfc" },
>> + { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, vf610_nfc_dt_ids);
>> +
>> +static int vf610_nfc_init_controller(struct vf610_nfc *nfc)
>> +{
>> + if (nfc->chip.options & NAND_BUSWIDTH_16)
>> + vf610_nfc_set(nfc, NFC_FLASH_CONFIG, CONFIG_16BIT);
>> + else
>> + vf610_nfc_clear(nfc, NFC_FLASH_CONFIG, CONFIG_16BIT);
>> +
>> + /* Set configuration register. */
>> + vf610_nfc_clear(nfc, NFC_FLASH_CONFIG, CONFIG_ADDR_AUTO_INCR_BIT);
>> + vf610_nfc_clear(nfc, NFC_FLASH_CONFIG, CONFIG_BUFNO_AUTO_INCR_BIT);
>> + vf610_nfc_clear(nfc, NFC_FLASH_CONFIG, CONFIG_BOOT_MODE_BIT);
>> + vf610_nfc_clear(nfc, NFC_FLASH_CONFIG, CONFIG_DMA_REQ_BIT);
>> + vf610_nfc_set(nfc, NFC_FLASH_CONFIG, CONFIG_FAST_FLASH_BIT);
>> +
>> + /* PAGE_CNT = 1 */
>> + vf610_nfc_set_field(nfc, NFC_FLASH_CONFIG, CONFIG_PAGE_CNT_MASK,
>> + CONFIG_PAGE_CNT_SHIFT, 1);
>> +
>> + return 0;
>> +}
>> +
>> +static int vf610_nfc_probe(struct platform_device *pdev)
>> +{
>> + struct vf610_nfc *nfc;
>> + struct resource *res;
>> + struct mtd_info *mtd;
>> + struct nand_chip *chip;
>> + int err = 0;
>> + int irq;
>> +
>> + nfc = devm_kzalloc(&pdev->dev, sizeof(*nfc), GFP_KERNEL);
>> + if (!nfc)
>> + return -ENOMEM;
>> +
>> + nfc->dev = &pdev->dev;
>> + mtd = &nfc->mtd;
>> + chip = &nfc->chip;
>> +
>> + mtd->priv = chip;
>> + mtd->owner = THIS_MODULE;
>> + mtd->dev.parent = nfc->dev;
>> + mtd->name = DRV_NAME;
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq <= 0)
>> + return -EINVAL;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + nfc->regs = devm_ioremap_resource(nfc->dev, res);
>> + if (IS_ERR(nfc->regs))
>> + return PTR_ERR(nfc->regs);
>> +
>> + nfc->clk = devm_clk_get(&pdev->dev, NULL);
>> + if (IS_ERR(nfc->clk))
>> + return PTR_ERR(nfc->clk);
>> +
>> + err = clk_prepare_enable(nfc->clk);
>> + if (err) {
>> + dev_err(nfc->dev, "Unable to enable clock!\n");
>> + return err;
>> + }
>> +
>> + chip->dn = nfc->dev->of_node;
>> + chip->dev_ready = vf610_nfc_dev_ready;
>> + chip->cmdfunc = vf610_nfc_command;
>> + chip->read_byte = vf610_nfc_read_byte;
>> + chip->read_word = vf610_nfc_read_word;
>> + chip->read_buf = vf610_nfc_read_buf;
>> + chip->write_buf = vf610_nfc_write_buf;
>> + chip->select_chip = vf610_nfc_select_chip;
>> +
>> + chip->options |= NAND_NO_SUBPAGE_WRITE;
>> +
>> + init_completion(&nfc->cmd_done);
>> +
>> + err = devm_request_irq(nfc->dev, irq, vf610_nfc_irq, 0, DRV_NAME, mtd);
>> + if (err) {
>> + dev_err(nfc->dev, "Error requesting IRQ!\n");
>> + goto error;
>> + }
>> +
>> + vf610_nfc_init_controller(nfc);
>> +
>> + /* first scan to find the device and get the page size */
>> + if (nand_scan_ident(mtd, 1, NULL)) {
>> + err = -ENXIO;
>> + goto error;
>> + }
>> +
>> + /* Bad block options. */
>> + if (chip->bbt_options & NAND_BBT_USE_FLASH)
>> + chip->bbt_options |= NAND_BBT_NO_OOB;
>> +
>> + /* Single buffer only, max 256 OOB minus ECC status */
>> + if (mtd->writesize + mtd->oobsize > PAGE_2K + 256 - 8) {
>> + dev_err(nfc->dev, "Unsupported flash page size\n");
>> + err = -ENXIO;
>> + goto error;
>> + }
>> +
>> + /* second phase scan */
>> + if (nand_scan_tail(mtd)) {
>> + err = -ENXIO;
>> + goto error;
>> + }
>> +
>> + /* Register device in MTD */
>> + mtd_device_parse_register(mtd, NULL,
>> + &(struct mtd_part_parser_data){
>> + .of_node = pdev->dev.of_node,
>> + },
>> + NULL, 0);
>> +
>> + platform_set_drvdata(pdev, mtd);
>> +
>> + return 0;
>> +
>> +error:
>> + clk_disable_unprepare(nfc->clk);
>> + return err;
>> +}
>> +
>> +static int vf610_nfc_remove(struct platform_device *pdev)
>> +{
>> + struct mtd_info *mtd = platform_get_drvdata(pdev);
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> +
>> + nand_release(mtd);
>> + clk_disable_unprepare(nfc->clk);
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int vf610_nfc_suspend(struct device *dev)
>> +{
>> + struct mtd_info *mtd = dev_get_drvdata(dev);
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> +
>> + clk_disable_unprepare(nfc->clk);
>> + return 0;
>> +}
>> +
>> +static int vf610_nfc_resume(struct device *dev)
>> +{
>> + struct mtd_info *mtd = dev_get_drvdata(dev);
>> + struct vf610_nfc *nfc = mtd_to_nfc(mtd);
>> +
>> + pinctrl_pm_select_default_state(dev);
>> +
>> + clk_prepare_enable(nfc->clk);
>> +
>> + vf610_nfc_init_controller(nfc);
>> + return 0;
>> +}
>> +#endif
>> +
>> +static SIMPLE_DEV_PM_OPS(vf610_nfc_pm_ops, vf610_nfc_suspend, vf610_nfc_resume);
>> +
>> +static struct platform_driver vf610_nfc_driver = {
>> + .driver = {
>> + .name = DRV_NAME,
>> + .of_match_table = vf610_nfc_dt_ids,
>> + .pm = &vf610_nfc_pm_ops,
>> + },
>> + .probe = vf610_nfc_probe,
>> + .remove = vf610_nfc_remove,
>> +};
>> +
>> +module_platform_driver(vf610_nfc_driver);
>> +
>> +MODULE_AUTHOR("Stefan Agner <stefan.agner@toradex.com>");
>> +MODULE_DESCRIPTION("Freescale VF610/MPC5125 NFC MTD NAND driver");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.4.5
>> 
>> 
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel [1]

 

Links:
------
[1] http://lists.infradead.org/mailman/listinfo/linux-arm-kernel