[U-Boot] [PATCH] sf: ensure flash device is in 3-byte address mode

[Jagan Teki]

On Tue, Oct 17, 2017 at 5:17 PM, Goldschmidt Simon
<sgoldschmidt at de.pepperl-fuchs.com> wrote:
> On some boards where the spi flash is not reset during warm reboot,
> the chip has to be manually set into 3-byte address mode.
>
> Signed-off-by: Simon Goldschmidt <sgoldschmidt at de.pepperl-fuchs.com>
> ---
>  drivers/mtd/spi/sf_internal.h |  2 ++
>  drivers/mtd/spi/spi_flash.c   | 53 +++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 55 insertions(+)
>
> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
> index 839cdbe1b0..06dee0a4ea 100644
> --- a/drivers/mtd/spi/sf_internal.h
> +++ b/drivers/mtd/spi/sf_internal.h
> @@ -62,6 +62,8 @@ enum spi_nor_option_flags {
>  #define CMD_READ_STATUS1               0x35
>  #define CMD_READ_CONFIG                        0x35
>  #define CMD_FLAG_STATUS                        0x70
> +#define CMD_EN4B                               0xB7
> +#define CMD_EX4B                               0xE9
>
>  /* Bank addr access commands */
>  #ifdef CONFIG_SPI_FLASH_BAR
> diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
> index 34f68881ed..8db2882075 100644
> --- a/drivers/mtd/spi/spi_flash.c
> +++ b/drivers/mtd/spi/spi_flash.c
> @@ -165,6 +165,55 @@ bar_end:
>  }
>  #endif
>
> +static int set_4byte(struct spi_flash *flash, const struct spi_flash_info *info,
> +               u8 enable)
> +{
> +       int ret;
> +       bool need_wren = false;
> +       u8 cmd;
> +
> +       if (flash->size <= SPI_FLASH_16MB_BOUN)
> +               return 0;
> +
> +       switch (JEDEC_MFR(info)) {
> +       case SPI_FLASH_CFI_MFR_STMICRO:
> +               /* Some Micron need WREN command; all will accept it */
> +               need_wren = true;
> +       case SPI_FLASH_CFI_MFR_MACRONIX:
> +       case SPI_FLASH_CFI_MFR_WINBOND:
> +               ret = spi_claim_bus(flash->spi);
> +               if (ret) {
> +                       debug("SF: Unable to claim SPI bus\n");
> +                       return ret;
> +               }
> +
> +               if (need_wren) {
> +                       ret = spi_flash_cmd_write_enable(flash);
> +                       if (ret < 0) {
> +                               debug("SF: enabling write failed\n");
> +                               spi_release_bus(flash->spi);
> +                               return ret;
> +                       }
> +               }
> +
> +               cmd = enable ? CMD_EN4B : CMD_EX4B;
> +               ret = spi_flash_cmd_write(flash->spi, &cmd, 1, NULL, 0);
> +               if (ret) {
> +                       debug("SF: fail to %s 4-byte address mode\n",
> +                               enable ? "enter" : "exit");
> +               }
> +               if (need_wren)
> +                       if (spi_flash_cmd_write_disable(flash) < 0)
> +                               debug("SF: disabling write failed\n");
> +               spi_release_bus(flash->spi);
> +               return ret;
> +       default:
> +               /* Spansion style handled by bar_write  */
> +               break;
> +       }
> +       return 0;
> +}
> +
>  #ifdef CONFIG_SF_DUAL_FLASH
>  static void spi_flash_dual(struct spi_flash *flash, u32 *addr)
>  {
> @@ -1086,6 +1135,10 @@ int spi_flash_scan(struct spi_flash *flash)
>                 flash->flags |= SNOR_F_USE_FSR;
>  #endif
>
> +       /* disable 4-byte addressing if the device exceeds 16MiB */
> +       if (flash->size > SPI_FLASH_16MB_BOUN)
> +               set_4byte(flash, info, 0);
> +

I've similar change on my patchwork, since no-one tested Will CC you
by re-basing it please have test?

thanks!
-- 
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.