[PATCH v13 3/3] mmc: mediatek: add support for SDIO eint wakup IRQ

[AngeloGioacchino Del Regno]

Il 23/06/22 11:04, Axe Yang ha scritto:
> Add support for eint IRQ when MSDC is used as an SDIO host. This
> feature requires SDIO device support async IRQ function. With this
> feature, SDIO host can be awakened by SDIO card in suspend state,
> without additional pin.
> 
> MSDC driver will time-share the SDIO DAT1 pin. During suspend, MSDC
> turn off clock and switch SDIO DAT1 pin to GPIO mode. And during
> resume, switch GPIO function back to DAT1 mode then turn on clock.
> 
> Some device tree property should be added or modified in MSDC node
> to support SDIO eint IRQ. Pinctrls "state_eint" is mandatory. Since
> this feature depends on asynchronous interrupts, "wakeup-source",
> "keep-power-in-suspend" and "cap-sdio-irq" flags are necessary, and
> the interrupts list should be extended(the interrupt named with
> sdio_wakeup):
>          &mmcX {
> 		...
> 		interrupt-names = "msdc", "sdio_wakeup";
> 		interrupts-extended = <...>,
>                                	      <&pio xxx IRQ_TYPE_LEVEL_LOW>;
>                  ...
>                  pinctrl-names = "default", "state_uhs", "state_eint";
>                  ...
>                  pinctrl-2 = <&mmc2_pins_eint>;
>                  ...
>                  cap-sdio-irq;
> 		keep-power-in-suspend;
> 		wakeup-source;
>                  ...
>          };
> 
> Co-developed-by: Yong Mao <yong.mao at mediatek.com>
> Signed-off-by: Yong Mao <yong.mao at mediatek.com>
> Signed-off-by: Axe Yang <axe.yang at mediatek.com>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>