Re: [PATCH v2 04/10] mmc: sunxi: Support controllers that can use both old and new timings

Maxime Ripard
2017-07-21T07:20:39Z

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On Thu, Jul 20, 2017 at 11:44:46AM +0800, Chen-Yu Tsai wrote:
> On the SoCs that introduced the new timing mode for MMC controllers,
> both the old (where the clock delays are set in the CCU) and new
> (where the clock delays are set in the MMC controller) timing modes
> are available, and we have to support them both. However there are
> two bits that control which mode is active. One is in the CCU, the
> other is in the MMC controller. The settings on both sides must be
> the same, or nothing will work.
>
> The sunxi-ng clock driver provides an API to query and set the
> active timing mode. At probe time, we try to set the active mode
> to the "new timing mode". If it succeeds, we can then use the MMC
> controller in the new mode. If not, we fall back to the old mode.
>
> Signed-off-by: Chen-Yu Tsai <wens-jdAy2FN1RRM@public.gmane.org>

Acked-by: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>

Thanks!
Maxime
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Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering