Re: [PATCH 15/22] hw/sd: ssi-sd: Support multiple block write

[Alistair Francis]

On Thu, Dec 31, 2020 at 3:47 AM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> From: Bin Meng <bin.meng@windriver.com>
>
> For a multiple block write operation, each block begins with a multi
> write start token. Unlike the SD mode that the multiple block write
> ends when receiving a STOP_TRAN command (CMD12), a special stop tran
> tocken is used to signal the card.
>
> Emulating this by manually sending a CMD12 to the SD card core, to
> bring it out of the receiving data state.
>
> Signed-off-by: Bin Meng <bin.meng@windriver.com>

Acked-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>
>  hw/sd/ssi-sd.c | 26 ++++++++++++++++++++++++--
>  1 file changed, 24 insertions(+), 2 deletions(-)
>
> diff --git a/hw/sd/ssi-sd.c b/hw/sd/ssi-sd.c
> index 21a96e91f0..6cf5d749c7 100644
> --- a/hw/sd/ssi-sd.c
> +++ b/hw/sd/ssi-sd.c
> @@ -99,6 +99,8 @@ OBJECT_DECLARE_SIMPLE_TYPE(ssi_sd_state, SSI_SD)
>  static uint32_t ssi_sd_transfer(SSIPeripheral *dev, uint32_t val)
>  {
>      ssi_sd_state *s = SSI_SD(dev);
> +    SDRequest request;
> +    uint8_t longresp[16];
>
>      /* Special case: allow CMD12 (STOP TRANSMISSION) while reading data.  */
>      if (s->mode == SSI_SD_DATA_READ && val == 0x4c) {
> @@ -115,9 +117,31 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, 
> uint32_t val)
>              return SSI_DUMMY;
>              break;
>          case SSI_TOKEN_SINGLE:
> +        case SSI_TOKEN_MULTI_WRITE:
>              DPRINTF("Start write block\n");
>              s->mode = SSI_SD_DATA_WRITE;
>              return SSI_DUMMY;
> +        case SSI_TOKEN_STOP_TRAN:
> +            DPRINTF("Stop multiple write\n");
> +
> +            /* manually issue cmd12 to stop the transfer */
> +            request.cmd = 12;
> +            request.arg = 0;
> +            s->arglen = sdbus_do_command(&s->sdbus, &request, longresp);
> +            if (s->arglen <= 0) {
> +                s->arglen = 1;
> +                /* a zero value indicates the card is busy */
> +                s->response[0] = 0;
> +                DPRINTF("SD card busy\n");
> +            } else {
> +                s->arglen = 1;
> +                /* a non-zero value indicates the card is ready */
> +                s->response[0] = SSI_DUMMY;
> +            }
> +
> +            s->mode = SSI_SD_RESPONSE;
> +            s->response_pos = 0;
> +            return SSI_DUMMY;
>          }
>
>          s->cmd = val & 0x3f;
> @@ -126,8 +150,6 @@ static uint32_t ssi_sd_transfer(SSIPeripheral *dev, 
> uint32_t val)
>          return SSI_DUMMY;
>      case SSI_SD_CMDARG:
>          if (s->arglen == 4) {
> -            SDRequest request;
> -            uint8_t longresp[16];
>              /* FIXME: Check CRC.  */
>              request.cmd = s->cmd;
>              request.arg = ldl_be_p(s->cmdarg);
> --
> 2.25.1
>
>