[U-Boot] [PATCH 3/5] spi: sf: Support byte program for sst spi flash

[Jagan Teki]

On 23 October 2014 19:06, Bin Meng <bmeng.cn at gmail.com> wrote:
> Currently if SST flash advertises SST_WP flag in the params table
> the word program command (ADh) with auto address increment will be
> used for the flash write op. However some SPI controllers do not
> support the word program command (like the Intel ICH 7), the byte
> programm command (02h) has to be used.
>
> A new TX operation mode SPI_OPM_TX_BP is introduced for such SPI
> controller to use byte program op for SST flash.
>
> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> ---
>  drivers/mtd/spi/sf_internal.h |  2 ++
>  drivers/mtd/spi/sf_ops.c      | 31 +++++++++++++++++++++++++++++++
>  drivers/mtd/spi/sf_probe.c    |  8 ++++++--
>  drivers/spi/ich.c             |  9 +++++++--
>  include/spi.h                 |  1 +
>  5 files changed, 47 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
> index 19d4914..c185e04 100644
> --- a/drivers/mtd/spi/sf_internal.h
> +++ b/drivers/mtd/spi/sf_internal.h
> @@ -77,6 +77,8 @@
>
>  int sst_write_wp(struct spi_flash *flash, u32 offset, size_t len,
>                 const void *buf);
> +int sst_write_bp(struct spi_flash *flash, u32 offset, size_t len,
> +               const void *buf);
>  #endif

I believe byte write is already been used within the sst_write_wp -
please check.

>
>  /* Send a single-byte command to the device and read the response */
> diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c
> index 85cf22d..3703acb 100644
> --- a/drivers/mtd/spi/sf_ops.c
> +++ b/drivers/mtd/spi/sf_ops.c
> @@ -516,4 +516,35 @@ int sst_write_wp(struct spi_flash *flash, u32 offset, size_t len,
>         spi_release_bus(flash->spi);
>         return ret;
>  }
> +
> +int sst_write_bp(struct spi_flash *flash, u32 offset, size_t len,
> +               const void *buf)

This function is simply calling existing sst_byte_write().

> +{
> +       size_t actual;
> +       int ret;
> +
> +       ret = spi_claim_bus(flash->spi);
> +       if (ret) {
> +               debug("SF: Unable to claim SPI bus\n");
> +               return ret;
> +       }
> +
> +       for (actual = 0; actual < len; actual++) {
> +               ret = sst_byte_write(flash, offset, buf + actual);
> +               if (ret) {
> +                       debug("SF: sst byte program failed\n");
> +                       break;
> +               }
> +               offset++;
> +       }
> +
> +       if (!ret)
> +               ret = spi_flash_cmd_write_disable(flash);
> +
> +       debug("SF: sst: program %s %zu bytes @ 0x%zx\n",
> +             ret ? "failure" : "success", len, offset - actual);
> +
> +       spi_release_bus(flash->spi);
> +       return ret;
> +}
>  #endif
> diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
> index 4d148d1..1b48955 100644
> --- a/drivers/mtd/spi/sf_probe.c
> +++ b/drivers/mtd/spi/sf_probe.c
> @@ -138,8 +138,12 @@ static struct spi_flash *spi_flash_validate_params(struct spi_slave *spi,
>         /* Assign spi_flash ops */
>         flash->write = spi_flash_cmd_write_ops;
>  #ifdef CONFIG_SPI_FLASH_SST
> -       if (params->flags & SST_WP)
> -               flash->write = sst_write_wp;
> +       if (params->flags & SST_WP) {
> +               if (flash->spi->op_mode_tx & SPI_OPM_TX_BP)
> +                       flash->write = sst_write_bp;
> +               else
> +                       flash->write = sst_write_wp;
> +       }
>  #endif
>         flash->erase = spi_flash_cmd_erase_ops;
>         flash->read = spi_flash_cmd_read_ops;
> diff --git a/drivers/spi/ich.c b/drivers/spi/ich.c
> index b356411..16730ec 100644
> --- a/drivers/spi/ich.c
> +++ b/drivers/spi/ich.c
> @@ -141,9 +141,14 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
>         ich->slave.max_write_size = ctlr.databytes;
>         ich->speed = max_hz;
>
> -       /* ICH 7 SPI controller only supports array read command */
> -       if (ctlr.ich_version == 7)
> +       /*
> +        * ICH 7 SPI controller only supports array read command
> +        * and byte program command for SST flash
> +        */
> +       if (ctlr.ich_version == 7) {
>                 ich->slave.op_mode_rx = SPI_OPM_RX_AS;
> +               ich->slave.op_mode_tx = SPI_OPM_TX_BP;
> +       }

SST commands(write) is different than normal flash commands,  I don't like
to change the controller driver to know the flash command usage.

May be this part can think later, try to see above comments.

>
>         return &ich->slave;
>  }
> diff --git a/include/spi.h b/include/spi.h
> index ffd6647..a4d3f5f 100644
> --- a/include/spi.h
> +++ b/include/spi.h
> @@ -34,6 +34,7 @@
>
>  /* SPI TX operation modes */
>  #define SPI_OPM_TX_QPP         1 << 0
> +#define SPI_OPM_TX_BP          1 << 1
>
>  /* SPI RX operation modes */
>  #define SPI_OPM_RX_AS          1 << 0
> --
> 1.8.2.1
>

thanks!
-- 
Jagan.