Re: [Qemu-devel] [PATCH 03/12] Reset enable and reset memory commands support.

[Peter Crosthwaite]

On Wed, Dec 16, 2015 at 4:57 AM,  <address@hidden> wrote:
> From: Marcin Krzeminski <address@hidden>
>
> Signed-off-by: Marcin Krzeminski <address@hidden>
> ---
>  hw/block/m25p80.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
>
> diff --git a/hw/block/m25p80.c b/hw/block/m25p80.c
> index bcb66a5..5e07b57 100644
> --- a/hw/block/m25p80.c
> +++ b/hw/block/m25p80.c
> @@ -231,6 +231,10 @@ typedef enum {
>      ERASE_4K = 0x20,
>      ERASE_32K = 0x52,
>      ERASE_SECTOR = 0xd8,
> +
> +    RESET_ENABLE = 0x66,
> +    RESET_MEMORY = 0x99,
> +

Extra blank not needed.

>  } FlashCMD;
>
>  typedef enum {
> @@ -258,6 +262,7 @@ typedef struct Flash {
>      uint8_t cmd_in_progress;
>      uint64_t cur_addr;
>      bool write_enable;
> +    bool reset_enable;
>      bool initialized;
>      uint8_t reset_pin;
>
> @@ -441,6 +446,7 @@ static void reset_memory(Flash *s)
>      s->pos = 0;
>      s->state = STATE_IDLE;
>      s->write_enable = false;
> +    s->reset_enable = false;
>
>      DB_PRINT_L(0, "Reset done.\n");
>  }
> @@ -554,6 +560,14 @@ static void decode_new_cmd(Flash *s, uint32_t value)
>          break;
>      case NOP:
>          break;
> +    case RESET_ENABLE:
> +        s->reset_enable = true;
> +        break;
> +    case RESET_MEMORY:
> +        if (s->reset_enable) {
> +            reset_memory(s);
> +        }
> +        break;

Reading an n25q256 datasheet, the RESET_ENABLE state is cancelled by
commands other that RESET_ENABLE or by bouncing the CS. A way to
implement this would be something like

if (value != RESET_MEMORY) {
    s->reset_enable = false;
}

before the switch of value as well as clearing reset_enable in m25p80_cs.

Regards,
Peter

>      default:
>          qemu_log_mask(LOG_GUEST_ERROR, "M25P80: Unknown cmd %x\n", value);
>          break;
> @@ -696,6 +710,7 @@ static const VMStateDescription vmstate_m25p80 = {
>          VMSTATE_UINT8(cmd_in_progress, Flash),
>          VMSTATE_UINT64(cur_addr, Flash),
>          VMSTATE_BOOL(write_enable, Flash),
> +        VMSTATE_BOOL(reset_enable, Flash),
>          VMSTATE_BOOL(initialized, Flash),
>          VMSTATE_UINT8(reset_pin, Flash),
>          VMSTATE_END_OF_LIST()
> --
> 2.5.0
>
>