Re: [PATCH 6/9] mtd: spi-nor: Support R/W for S25FS-S family flash

[Han Xu]

On Wed, Apr 20, 2016 at 5:34 PM, Han Xu <han.xu@xxxxxxx> wrote:
>
>
> ________________________________________
> From: Yunhui Cui <B56489@xxxxxxxxxxxxx>
> Sent: Wednesday, April 13, 2016 9:50 PM
> To: dwmw2@xxxxxxxxxxxxx; computersforpeace@xxxxxxxxx; han.xu@xxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-mtd@xxxxxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; Yao Yuan; Yunhui Cui
> Subject: [PATCH 6/9] mtd: spi-nor: Support R/W for S25FS-S family flash
>
> From: Yunhui Cui <yunhui.cui@xxxxxxx>
>
> With the physical sectors combination, S25FS-S family flash
> requires some special operations for read/write functions.
>
> Signed-off-by: Yunhui Cui <yunhui.cui@xxxxxxx>
> ---
>  drivers/mtd/spi-nor/spi-nor.c | 59 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 59 insertions(+)
>
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 157841d..91ee920 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -39,6 +39,10 @@
>
>  #define SPI_NOR_MAX_ID_LEN     6
>  #define SPI_NOR_MAX_ADDR_WIDTH 4
> +/* Added for S25FS-S family flash */
> +#define SPINOR_CONFIG_REG3_OFFSET      0x800004
> +#define CR3V_4KB_ERASE_UNABLE  0x8
> +#define SPINOR_S25FS_FAMILY_ID 0x81
>
>  struct flash_info {
>         char            *name;
> @@ -78,6 +82,7 @@ struct flash_info {
>  };
>
>  #define JEDEC_MFR(info)        ((info)->id[0])
> +#define EXT_ID(info)   ((info)->id[5])
>
>  static const struct flash_info *spi_nor_match_id(const char *name);
>
> @@ -881,6 +886,7 @@ static const struct flash_info spi_nor_ids[] = {
>          */
>         { "s25sl032p",  INFO(0x010215, 0x4d00,  64 * 1024,  64, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
>         { "s25sl064p",  INFO(0x010216, 0x4d00,  64 * 1024, 128, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> +       { "s25fs256s1", INFO6(0x010219, 0x4d0181, 64 * 1024, 512, 0)},
>         { "s25fl256s0", INFO(0x010219, 0x4d00, 256 * 1024, 128, 0) },
>         { "s25fl256s1", INFO(0x010219, 0x4d01,  64 * 1024, 512, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
>         { "s25fl512s",  INFO(0x010220, 0x4d00, 256 * 1024, 256, SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ) },
> @@ -1018,6 +1024,53 @@ static const struct flash_info *spi_nor_read_id(struct spi_nor *nor)
>         return ERR_PTR(-ENODEV);
>  }
>
> +/*
> + * The S25FS-S family physical sectors may be configured as a
> + * hybrid combination of eight 4-kB parameter sectors
> + * at the top or bottom of the address space with all
> + * but one of the remaining sectors being uniform size.
> + * The Parameter Sector Erase commands (20h or 21h) must
> + * be used to erase the 4-kB parameter sectors individually.
> + * The Sector (uniform sector) Erase commands (D8h or DCh)
> + * must be used to erase any of the remaining
> + * sectors, including the portion of highest or lowest address
> + * sector that is not overlaid by the parameter sectors.
> + * The uniform sector erase command has no effect on parameter sectors.
> + */
> +static int spansion_s25fs_disable_4kb_erase(struct spi_nor *nor)
> +{
> +       struct fsl_qspi *q;
> +       u32 cr3v_addr  = SPINOR_CONFIG_REG3_OFFSET;
> +       u8 cr3v = 0x0;
> +       int ret = 0x0;
> +
> +       q = nor->priv;
> +
> +       nor->cmd_buf[2] = cr3v_addr >> 16;
> +       nor->cmd_buf[1] = cr3v_addr >> 8;
> +       nor->cmd_buf[0] = cr3v_addr >> 0;
>
> I feel it's hacking code.
>
> Hi Brian, do we have any plan to support this special case? The RDAR(
> Read Any Register) needs an extra address parameter.

Hi Brian,

I was wondering if you have some free time to check the questions. Thanks.
>
> +
> +       ret = nor->read_reg(nor, SPINOR_OP_SPANSION_RDAR, &cr3v, 1);
> +       if (ret)
> +               return ret;
> +       if (cr3v & CR3V_4KB_ERASE_UNABLE)
> +               return 0;
> +       ret = nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0);
> +       if (ret)
> +               return ret;
> +       cr3v = CR3V_4KB_ERASE_UNABLE;
> +       nor->program_opcode = SPINOR_OP_SPANSION_WRAR;
> +       nor->write(nor, cr3v_addr, 1, NULL, &cr3v);
> +
> +       ret = nor->read_reg(nor, SPINOR_OP_SPANSION_RDAR, &cr3v, 1);
> +       if (ret)
> +               return ret;
> +       if (!(cr3v & CR3V_4KB_ERASE_UNABLE))
> +               return -EPERM;
> +
> +       return 0;
> +}
> +
>  static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
>                         size_t *retlen, u_char *buf)
>  {
> @@ -1311,6 +1364,12 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
>                 spi_nor_wait_till_ready(nor);
>         }
>
> +       if (EXT_ID(info) == SPINOR_S25FS_FAMILY_ID) {
> +               ret = spansion_s25fs_disable_4kb_erase(nor);
> +               if (ret)
> +                       return ret;
> +       }
> +
>         if (!mtd->name)
>                 mtd->name = dev_name(dev);
>         mtd->priv = nor;
> --
> 2.1.0.27.g96db324
>
>
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