[U-Boot] [V4 1/2] sf: Add clear flag status register operation on Micron chips

[Jagan Teki]

On 23 July 2015 at 15:24, Zhiqiang Hou <B48286 at freescale.com> wrote:
> From: Hou Zhiqiang <B48286 at freescale.com>
>
> Add clear flag status register operation that was required by Micron SPI
> flash chips after reading the flag status register to check if the erase
> and program operations complete or an error occur.
>
> Signed-off-by: Hou Zhiqiang <B48286 at freescale.com>
> Signed-off-by: Mingkai.Hu <Mingkai.Hu at freescale.com>
> ---
>  drivers/mtd/spi/sf_internal.h |  9 +++++++++
>  drivers/mtd/spi/sf_ops.c      | 40 ++++++++++++++++++++++++++++++++--------
>  2 files changed, 41 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
> index 9fb5557..703d4a7 100644
> --- a/drivers/mtd/spi/sf_internal.h
> +++ b/drivers/mtd/spi/sf_internal.h
> @@ -73,6 +73,7 @@ enum {
>  #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
> @@ -96,6 +97,8 @@ enum {
>  #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)
> @@ -182,6 +185,12 @@ 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_slave *spi)
> +{
> +       return spi_flash_cmd(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 38592f5..cbb9f00 100644
> --- a/drivers/mtd/spi/sf_ops.c
> +++ b/drivers/mtd/spi/sf_ops.c
> @@ -160,6 +160,7 @@ static int spi_flash_poll_status(struct spi_slave *spi, 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;
>
> @@ -182,22 +183,45 @@ static int spi_flash_poll_status(struct spi_slave *spi, 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");
> +               if (cmd == CMD_FLAG_STATUS) {
> +                       if (spi_flash_cmd_clear_flag_status(spi) < 0)
> +                               debug("SF: clear flag status failed\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;
> +               }

Don't add any #ifdef for STMICRO, as this clear status only require when FSR
used, so try to do that when ever FSR does.

Something like here:

/* read */
spi_xfer for FSR and then CFSR

/* status */
spi_xfer for FSR and then CFSR

Let me know if you need any inputs.

>
> -       /* Timed out */
> -       debug("SF: time out!\n");
> -       return -1;
> +               if (spi_flash_cmd_clear_flag_status(spi) < 0) {
> +                       debug("SF: clear flag status failed\n");
> +                       ret = -1;
> +               }
> +       }
> +#endif
> +       return ret;
>  }
>
>  int spi_flash_cmd_wait_ready(struct spi_flash *flash, unsigned long timeout)
> @@ -252,7 +276,7 @@ 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;
> --
> 2.1.0.27.g96db324

thanks!
-- 
Jagan | openedev.