Re: [PATCH v3 2/4] mmc: omap_hsmmc: Enable SDIO IRQ.

[Kumar Gala <galak@codeaurora.org>]

On Oct 5, 2013, at 6:17 AM, Andreas Fenkart wrote:

> For now, only support SDIO interrupt if we are booted with
> DT. This is because some platforms need special quirks. And
> we don't want to add new legacy mux platform init code
> callbacks any longer as we are moving to DT based booting
> anyways.
> 
> Broken hardware, missing the swakueup line, should fallback
> to polling, by setting 'ti,quirk-swakup-missing' in the
> device tree. Otherwise pending SDIO IRQ are not detected
> while in suspend. This affects am33xx processors.
> 
> Signed-off-by: Andreas Fenkart <afenkart@gmail.com>
> 
> diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
> index ed271fc..1136e6b 100644
> --- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
> +++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
> @@ -20,6 +20,24 @@ ti,dual-volt: boolean, supports dual voltage cards
> ti,non-removable: non-removable slot (like eMMC)
> ti,needs-special-reset: Requires a special softreset sequence
> ti,needs-special-hs-handling: HSMMC IP needs special setting for handling High Speed
> +ti,quirk-swakup-missing: SOC missing the swakeup line, will not detect
> +SDIO irq while in suspend. Fallback to polling. Affected chips are
> +am335x,
> +
> +                            ------
> +                            | PRCM |
> +                             ------
> +                              ^ |
> +                      swakeup | | fclk
> +                              | v
> +      ------                -------               -----
> +     | card | -- CIRQ -->  | hsmmc | -- IRQ -->  | CPU |
> +      ------                -------               -----
> +
> +In suspend the fclk is off and the module is disfunctional. Even
> +register reads will fail. A small logic in the host will request fclk
> +restore, when an external event is detected. Once the clock is
> +restored, the host detects the event normally.
> 
> Example:
> 	mmc1: mmc@0x4809c000 {

For the DT-Binding portion:

Acked-by: Kumar Gala <galak@codeaurora.org>

- k

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