Re: [Qemu-devel] [PATCH v3] hw/m25p80.c: add WRSR(0x01) support

[Peter Crosthwaite]

On Mon, Feb 4, 2013 at 7:56 PM, Kuo-Jung Su <address@hidden> wrote:
> From: Kuo-Jung Su <address@hidden>
>
> Atmel, SST and Intel/Numonyx serial flash tend to power up
> with the software protection bits set.
> And thus the new m25p80.c in linux kernel would always tries
> to use WREN(0x06) + WRSR(0x01) to turn-off the protection.
>
> The WEL(0x02) of status register is supposed to be cleared after
> WRSR(0x01). There are also some drivers (i.e mine for RTOSes)
> would check the WEL(0x02) in status register to make sure the
> protection is correctly turned off.
>
> Signed-off-by: Kuo-Jung Su <address@hidden>

Reviewed-by: Peter Crosthwaite <address@hidden>

> Cc: Peter Crosthwaite <address@hidden>
> Cc: Peter Maydell <address@hidden>
> Cc: Edgar E. Iglesias <address@hidden>
> ---
>  Changes for v3:
>    - remove s->state = STATE_IDLE in complete_collecting_data()
>
>  Changes for v2:
>    - coding style fix
>
>  hw/m25p80.c |   15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/hw/m25p80.c b/hw/m25p80.c
> index 788c196..461b41c 100644
> --- a/hw/m25p80.c
> +++ b/hw/m25p80.c
> @@ -184,6 +184,7 @@ static const FlashPartInfo known_devices[] = {
>
>  typedef enum {
>      NOP = 0,
> +    WRSR = 0x1,
>      WRDI = 0x4,
>      RDSR = 0x5,
>      WREN = 0x6,
> @@ -379,6 +380,11 @@ static void complete_collecting_data(Flash *s)
>      case ERASE_SECTOR:
>          flash_erase(s, s->cur_addr, s->cmd_in_progress);
>          break;
> +    case WRSR:
> +        if (s->write_enable) {
> +            s->write_enable = false;
> +        }
> +        break;
>      default:
>          break;
>      }
> @@ -443,6 +449,15 @@ static void decode_new_cmd(Flash *s, uint32_t value)
>          s->state = STATE_COLLECTING_DATA;
>          break;
>
> +    case WRSR:
> +        if (s->write_enable) {
> +            s->needed_bytes = 1;
> +            s->pos = 0;
> +            s->len = 0;
> +            s->state = STATE_COLLECTING_DATA;
> +        }
> +        break;
> +
>      case WRDI:
>          s->write_enable = false;
>          break;
> --
> 1.7.9.5
>
>