Re: [PATCH v3 06/21] sd: emmc: Update CMD8 to send EXT_CSD register

[Cédric Le Goater]

On 2/28/21 8:33 PM, Sai Pavan Boddu wrote:
> From: Vincent Palatin <vpalatin@chromium.org>
> 
> Sends the EXT_CSD register as response to CMD8.
> 
> Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
> Signed-off-by: Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>
> ---
>  hw/sd/sd.c | 52 ++++++++++++++++++++++++++++++++++++----------------
>  1 file changed, 36 insertions(+), 16 deletions(-)
> 
> diff --git a/hw/sd/sd.c b/hw/sd/sd.c
> index a26695b..181e7e2 100644
> --- a/hw/sd/sd.c
> +++ b/hw/sd/sd.c
> @@ -1141,24 +1141,37 @@ static sd_rsp_type_t sd_normal_command(SDState *sd, 
> SDRequest req)
>          }
>          break;
>  
> -    case 8: /* CMD8:   SEND_IF_COND */
> -        if (sd->spec_version < SD_PHY_SPECv2_00_VERS) {
> -            break;
> -        }
> -        if (sd->state != sd_idle_state) {
> -            break;
> -        }
> -        sd->vhs = 0;
> -
> -        /* No response if not exactly one VHS bit is set.  */
> -        if (!(req.arg >> 8) || (req.arg >> (ctz32(req.arg & ~0xff) + 1))) {
> -            return sd->spi ? sd_r7 : sd_r0;
> -        }
> +    case 8:    /* CMD8:   SEND_IF_COND / SEND_EXT_CSD */
> +        if (sd->emmc) {
> +            switch (sd->state) {
> +            case sd_transfer_state:
> +                /* MMC : Sends the EXT_CSD register as a Block of data */
> +                sd->state = sd_sendingdata_state;
> +                memcpy(sd->data, sd->ext_csd, sizeof(sd->ext_csd));
> +                sd->data_start = addr;
> +                sd->data_offset = 0;
> +                return sd_r1;
> +            default:
> +                break;
> +            }

This is big enough to be a SDCardClass handler.

Thanks,

C.


> +        } else {
> +            if (sd->spec_version < SD_PHY_SPECv2_00_VERS) {
> +                break;
> +            }
> +            if (sd->state != sd_idle_state) {
> +                break;
> +            }
> +            sd->vhs = 0;
>  
> -        /* Accept.  */
> -        sd->vhs = req.arg;
> -        return sd_r7;
> +            /* No response if not exactly one VHS bit is set.  */
> +            if (!(req.arg >> 8) || (req.arg >> (ctz32(req.arg & ~0xff) + 
> 1))) {
> +                return sd->spi ? sd_r7 : sd_r0;
> +            }
>  
> +            /* Accept.  */
> +            sd->vhs = req.arg;
> +            return sd_r7;
> +        }
>      case 9: /* CMD9:   SEND_CSD */
>          switch (sd->state) {
>          case sd_standby_state:
> @@ -2081,6 +2094,13 @@ uint8_t sd_read_byte(SDState *sd)
>              sd->state = sd_transfer_state;
>          break;
>  
> +    case 8:     /* CMD8: SEND_EXT_CSD on MMC */
> +        ret = sd->data[sd->data_offset++];
> +        if (sd->data_offset >= sizeof(sd->ext_csd)) {
> +            sd->state = sd_transfer_state;
> +        }
> +        break;
> +
>      case 9:     /* CMD9:   SEND_CSD */
>      case 10:    /* CMD10:  SEND_CID */
>          ret = sd->data[sd->data_offset ++];
>