[U-Boot] [PATCH] sf: Add support for flag status register on Micron chips

[Jagan Teki]

On 29 August 2014 12:24, Hou Zhiqiang <B48286 at freescale.com> wrote:
> Add clear flag status register operation that some Micron SPI flash
> chips required after reading the flag status register to check some
> operations completion.
>
> Signed-off-by: Hou Zhiqiang <B48286 at freescale.com>
> ---
> Based on git://git.denx.de/u-boot.git.
> It also can be applied to git://www.denx.de/git/u-boot-mpc85xx.git.
> Tested on board T2080QDS and T2080RDB.

Flag status register support is been added for stmicro flashes which
are >= 512MB
sizes.

#ifdef CONFIG_SPI_FLASH_STMICRO
        if (params->flags & E_FSR)
                flash->poll_cmd = CMD_FLAG_STATUS;
#endif

Please check the condition on current tree bases, and let me know for
any questions.

>
>  drivers/mtd/spi/sf_internal.h |  9 +++++++++
>  drivers/mtd/spi/sf_ops.c      | 36 ++++++++++++++++++++++++++++--------
>  2 files changed, 37 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
> index 6bcd522..162dd87 100644
> --- a/drivers/mtd/spi/sf_internal.h
> +++ b/drivers/mtd/spi/sf_internal.h
> @@ -36,6 +36,7 @@
>  #define CMD_WRITE_ENABLE               0x06
>  #define CMD_READ_CONFIG                        0x35
>  #define CMD_FLAG_STATUS                        0x70
> +#define CMD_CLEAR_FLAG_STATUS          0x50
>
>  /* Read commands */
>  #define CMD_READ_ARRAY_SLOW            0x03
> @@ -59,6 +60,8 @@
>  #define STATUS_QEB_WINSPAN             (1 << 1)
>  #define STATUS_QEB_MXIC                        (1 << 6)
>  #define STATUS_PEC                     (1 << 7)
> +#define STATUS_PROT                    (1 << 1)
> +#define STATUS_ERASE                   (1 << 5)
>
>  /* Flash timeout values */
>  #define SPI_FLASH_PROG_TIMEOUT         (2 * CONFIG_SYS_HZ)
> @@ -120,6 +123,12 @@ static inline int spi_flash_cmd_write_disable(struct spi_flash *flash)
>         return spi_flash_cmd(flash->spi, CMD_WRITE_DISABLE, NULL, 0);
>  }
>
> +/* Clear flag status register */
> +static inline int spi_flash_cmd_clear_flag_status(struct spi_flash *flash)
> +{
> +       return spi_flash_cmd(flash->spi, CMD_CLEAR_FLAG_STATUS, NULL, 0);
> +}
> +
>  /*
>   * Send the read status command to the device and wait for the wip
>   * (write-in-progress) bit to clear itself.
> diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c
> index 85cf22d..08ff1df 100644
> --- a/drivers/mtd/spi/sf_ops.c
> +++ b/drivers/mtd/spi/sf_ops.c
> @@ -160,6 +160,7 @@ int spi_flash_cmd_wait_ready(struct spi_flash *flash, unsigned long timeout)
>         unsigned long timebase;
>         unsigned long flags = SPI_XFER_BEGIN;
>         int ret;
> +       int out_of_time = 1;
>         u8 status;
>         u8 check_status = 0x0;
>         u8 poll_bit = STATUS_WIP;
> @@ -186,22 +187,41 @@ int spi_flash_cmd_wait_ready(struct spi_flash *flash, unsigned long timeout)
>                 WATCHDOG_RESET();
>
>                 ret = spi_xfer(spi, 8, NULL, &status, 0);
> -               if (ret)
> +               if (ret) {
> +                       spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
>                         return -1;
> +               }
>
> -               if ((status & poll_bit) == check_status)
> +               if ((status & poll_bit) == check_status) {
> +                       out_of_time = 0;
>                         break;
> +               }
>
>         } while (get_timer(timebase) < timeout);
>
>         spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
>
> -       if ((status & poll_bit) == check_status)
> -               return 0;
> +       if (out_of_time) {
> +               /* Timed out */
> +               debug("SF: time out!\n");
> +               ret = -1;
> +       }
> +#ifdef CONFIG_SPI_FLASH_STMICRO
> +       else if (cmd == CMD_FLAG_STATUS) {
> +               if (!(status & (STATUS_PROT | STATUS_ERASE))) {
> +                       ret = 0;
> +               } else {
> +                       debug("SF: flag status error");
> +                       ret = -1;
> +               }
>
> -       /* Timed out */
> -       debug("SF: time out!\n");
> -       return -1;
> +               if (spi_flash_cmd_clear_flag_status(flash) < 0) {
> +                       debug("SF: clear flag status failed\n");
> +                       ret = -1;
> +               }
> +       }
> +#endif
> +       return ret;
>  }
>
>  int spi_flash_write_common(struct spi_flash *flash, const u8 *cmd,
> @@ -234,7 +254,7 @@ int spi_flash_write_common(struct spi_flash *flash, const u8 *cmd,
>
>         ret = spi_flash_cmd_wait_ready(flash, timeout);
>         if (ret < 0) {
> -               debug("SF: write %s timed out\n",
> +               debug("SF: write %s failed\n",
>                       timeout == SPI_FLASH_PROG_TIMEOUT ?
>                         "program" : "page erase");
>                 return ret;
> --
> 1.8.5

thanks!
-- 
Jagan.