Re: [PATCH 02/10] sdhci: aspeed: Add SDR50 support

[Andrew Jeffery]

Hi Chin-Ting,

Sorry for the delay in looking at your series.

On Wed, 22 Sep 2021, at 20:01, Chin-Ting Kuo wrote:
> From the analog waveform analysis result, SD/SDIO controller
> of AST2600 cannot always work well with 200MHz. The upper bound
> stable frequency for SD/SDIO controller is 100MHz. Thus, SDR50
> supported bit, instead of SDR104, in capability 2 register
> should be set in advance.
>
> Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@xxxxxxxxxxxxxx>
> ---
>  drivers/mmc/host/sdhci-of-aspeed.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-of-aspeed.c 
> b/drivers/mmc/host/sdhci-of-aspeed.c
> index 6e4e132903a6..c6eaeb02e3f9 100644
> --- a/drivers/mmc/host/sdhci-of-aspeed.c
> +++ b/drivers/mmc/host/sdhci-of-aspeed.c
> @@ -35,6 +35,8 @@
>  #define ASPEED_SDC_CAP1_1_8V           (0 * 32 + 26)
>  /* SDIO{14,24} */
>  #define ASPEED_SDC_CAP2_SDR104         (1 * 32 + 1)
> +/* SDIO{14,24} */

I don't think we need to duplicate this comment.

> +#define ASPEED_SDC_CAP2_SDR50          (1 * 32 + 0)

Can we keep the defines in increasing bit order (i.e. put 
ASPEED_SDC_CAP2_SDR50 above ASPEED_SDC_CAP2_SDR104)?

> 
>  struct aspeed_sdc {
>  	struct clk *clk;
> @@ -410,11 +412,17 @@ static int aspeed_sdhci_probe(struct 
> platform_device *pdev)
>  	sdhci_get_of_property(pdev);
> 
>  	if (of_property_read_bool(np, "mmc-hs200-1_8v") ||
> +		of_property_read_bool(np, "sd-uhs-sdr50") ||

Minor formatting issue, but can you make sure all the conditions are 
aligned vertically from the left?

>  	    of_property_read_bool(np, "sd-uhs-sdr104")) {
>  		aspeed_sdc_set_slot_capability(host, dev->parent, ASPEED_SDC_CAP1_1_8V,
>  					       true, slot);
>  	}
> 
> +	if (of_property_read_bool(np, "sd-uhs-sdr50")) {
> +		aspeed_sdc_set_slot_capability(host, dev->parent, ASPEED_SDC_CAP2_SDR50,
> +					       true, slot);
> +	}
> +
>  	if (of_property_read_bool(np, "sd-uhs-sdr104")) {
>  		aspeed_sdc_set_slot_capability(host, dev->parent, ASPEED_SDC_CAP2_SDR104,
>  					       true, slot);
> -- 
> 2.17.1