Re: [PATCH] mmc: atmel-mci: enable 8 bits buswidth support

[Alexandre Belloni]

On 29/01/2019 17:49:12+0100, Nicolas Ferre wrote:
> This patch adds support for 8-bit buswidth.
> Relevant SDCR value modified.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
Reviewed-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>

> ---
>  drivers/mmc/host/atmel-mci.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
> index 47189f9ed4e2..735aa5871358 100644
> --- a/drivers/mmc/host/atmel-mci.c
> +++ b/drivers/mmc/host/atmel-mci.c
> @@ -1410,6 +1410,9 @@ static void atmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>  	case MMC_BUS_WIDTH_4:
>  		slot->sdc_reg |= ATMCI_SDCBUS_4BIT;
>  		break;
> +	case MMC_BUS_WIDTH_8:
> +		slot->sdc_reg |= ATMCI_SDCBUS_8BIT;
> +		break;
>  	}
>  
>  	if (ios->clock) {
> @@ -2275,8 +2278,11 @@ static int atmci_init_slot(struct atmel_mci *host,
>  	 * use only one bit for data to prevent fifo underruns and overruns
>  	 * which will corrupt data.
>  	 */
> -	if ((slot_data->bus_width >= 4) && host->caps.has_rwproof)
> +	if ((slot_data->bus_width >= 4) && host->caps.has_rwproof) {
>  		mmc->caps |= MMC_CAP_4_BIT_DATA;
> +		if (slot_data->bus_width >= 8)
> +			mmc->caps |= MMC_CAP_8_BIT_DATA;
> +	}
>  
>  	if (atmci_get_version(host) < 0x200) {
>  		mmc->max_segs = 256;
> -- 
> 2.17.1
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com