Re: [PATCH v3 11/15] mmc: sdhci-of-arasan: Add ability to export card clock

From: Adrian Hunter
Date: Wed Jun 22 2016 - 08:39:25 EST


On 20/06/16 20:56, Douglas Anderson wrote:
> Some SD/eMMC PHYs (like the PHY from Arasan that is designed to work
> with arasan,sdhci-5.1) need to know the card clock in order to function
> properly. Let's add the ability to expose this clock. Any PHY that
> needs to know the clock rate can add a reference and query the clock
> rate.
>
> At the moment we register a CLK_GET_RATE_NOCACHE clock that simply
> allows querying the clock. This allows us to be less intrusive with
> regards to the main SDHCI driver, which has complex logic for adjusting
> the SD clock. Right now we always fully power cycle the PHY when the
> clock changes and that gives the PHY a good chance to query our clock.
>
> Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
> Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>