[U-Boot] [PATCH v4 14/14] sf: Add Flag status register polling support

[Simon Glass]

Hi Jagan,

On Thu, Jun 13, 2013 at 1:55 PM, Jagannadha Sutradharudu Teki <
jagannadha.sutradharudu-teki at xilinx.com> wrote:

> Flag status register polling is required for micron 512Mb flash
> devices onwards, for performing erase/program operations.
>
> Like polling for WIP(Write-In-Progress) bit in read status register,
> spi_flash_cmd_wait_ready will poll for PEC(Program-Erase-Control)
> bit in flag status register.
>
> Signed-off-by: Jagannadha Sutradharudu Teki <jaganna at xilinx.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> ---
> Changes for v4:
>         - Remove STMICRO config, discover poll_cmd at probe
> Changes for v3:
>         - none
> Changes for v2:
>         - none
>
>  drivers/mtd/spi/spi_flash.c          | 21 +++++++++++++++++----
>  drivers/mtd/spi/spi_flash_internal.h |  2 ++
>  include/spi_flash.h                  |  3 +++
>  3 files changed, 22 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
> index e5b401f..c439601 100644
> --- a/drivers/mtd/spi/spi_flash.c
> +++ b/drivers/mtd/spi/spi_flash.c
> @@ -200,12 +200,19 @@ int spi_flash_cmd_wait_ready(struct spi_flash
> *flash, unsigned long timeout)
>         unsigned long timebase;
>         int ret;
>         u8 status;
> +       u8 check_status = 0x0;
>         u8 poll_bit = STATUS_WIP;
> -       u8 cmd = CMD_READ_STATUS;
> +       u8 cmd = flash->poll_cmd;
> +
> +       if (cmd == CMD_FLAG_STATUS) {
> +               poll_bit = STATUS_PEC;
> +               check_status = poll_bit;
> +       }
>
>         ret = spi_xfer(spi, 8, &cmd, NULL, SPI_XFER_BEGIN);
>         if (ret) {
> -               debug("SF: Failed to send command %02x: %d\n", cmd, ret);
> +               debug("SF: fail to read %s status register\n",
> +                       cmd == CMD_READ_STATUS ? "read" : "flag");
>                 return ret;
>         }
>
> @@ -217,14 +224,14 @@ int spi_flash_cmd_wait_ready(struct spi_flash
> *flash, unsigned long timeout)
>                 if (ret)
>                         return -1;
>
> -               if ((status & poll_bit) == 0)
> +               if ((status & poll_bit) == check_status)
>                         break;
>
>         } while (get_timer(timebase) < timeout);
>
>         spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
>
> -       if ((status & poll_bit) == 0)
> +       if ((status & poll_bit) == check_status)
>                 return 0;
>
>         /* Timed out */
> @@ -542,6 +549,12 @@ struct spi_flash *spi_flash_probe(unsigned int bus,
> unsigned int cs,
>                 goto err_manufacturer_probe;
>  #endif
>
> +       /* Discover the poll_cmd, as STMICRO is something different */
> +       flash->poll_cmd = CMD_READ_STATUS;
>

Move this line into spi_flash_do_alloc()

+       if ((*idp == SPI_FLASH_STMICRO_IDCODE0) &&
> +                       (flash->size >= 0x4000000))
> +               flash->poll_cmd = CMD_FLAG_STATUS;
>

...and the above into the stmicro.c's probe handler


> +
>  #ifdef CONFIG_OF_CONTROL
>         if (spi_flash_decode_fdt(gd->fdt_blob, flash)) {
>                 debug("SF: FDT decode error\n");
> diff --git a/drivers/mtd/spi/spi_flash_internal.h
> b/drivers/mtd/spi/spi_flash_internal.h
> index e9b85bf..8147f27 100644
> --- a/drivers/mtd/spi/spi_flash_internal.h
> +++ b/drivers/mtd/spi/spi_flash_internal.h
> @@ -22,6 +22,7 @@
>  #define CMD_PAGE_PROGRAM               0x02
>  #define CMD_WRITE_DISABLE              0x04
>  #define CMD_READ_STATUS                        0x05
> +#define CMD_FLAG_STATUS                        0x70
>  #define CMD_WRITE_ENABLE               0x06
>  #define CMD_ERASE_4K                   0x20
>  #define CMD_ERASE_32K                  0x52
> @@ -45,6 +46,7 @@
>
>  /* Common status */
>  #define STATUS_WIP                     0x01
> +#define STATUS_PEC                     0x80
>
>  /* Send a single-byte command to the device and read the response */
>  int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, size_t
> len);
> diff --git a/include/spi_flash.h b/include/spi_flash.h
> index 1de193a..e94e59c 100644
> --- a/include/spi_flash.h
> +++ b/include/spi_flash.h
> @@ -44,6 +44,9 @@ struct spi_flash {
>         /* Current flash bank */
>         u8              bank_curr;
>  #endif
> +       /* Poll cmd - for flash erase/program */
> +       u8              poll_cmd;
> +
>         void *memory_map;       /* Address of read-only SPI flash access */
>         int             (*read)(struct spi_flash *flash, u32 offset,
>                                 size_t len, void *buf);
> --
> 1.8.3
>
>
> Regards,
Simon