Re: [PATCH v8 1/3] dt-bindings: mmc: mtk-sd: extend interrupts and pinctrls properties

From: Axe Yang <axe.yang@mediatek.com>
To: Rob Herring <robh@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
	Chaotian Jing <chaotian.jing@mediatek.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	Satya Tangirala <satyat@google.com>,
	"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Lucas Stach <dev@lynxeye.de>,
	"Eric Biggers" <ebiggers@google.com>,
	Andrew Jeffery <andrew@aj.id.au>,
	"Stephen Boyd" <swboyd@chromium.org>,
	Kiwoong Kim <kwmad.kim@samsung.com>, Yue Hu <huyue2@yulong.com>,
	Tian Tao <tiantao6@hisilicon.com>,
	<angelogioacchino.delregno@collabora.com>,
	<linux-mmc@vger.kernel.org>, <devicetree@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-mediatek@lists.infradead.org>
Subject: Re: [PATCH v8 1/3] dt-bindings: mmc: mtk-sd: extend interrupts and pinctrls properties
Date: Tue, 22 Mar 2022 09:35:01 +0800	[thread overview]
Message-ID: <b03df175f871ee9a6561862f5bd7bceb9cafbde1.camel@mediatek.com> (raw)
In-Reply-To: <YjkKURNzg8JPbXcg@robh.at.kernel.org>

On Mon, 2022-03-21 at 18:29 -0500, Rob Herring wrote:
> On Mon, Mar 21, 2022 at 07:51:32PM +0800, Axe Yang wrote:
> > Extend interrupts and pinctrls for SDIO wakeup interrupt feature.
> > This feature allow SDIO devices alarm asynchronous interrupt to
> > host
> > even when host stop providing clock to SDIO card. An extra wakeup
> > interrupt and pinctrl states for SDIO DAT1 pin state switching are
> > required in this scenario.
> > 
> > Signed-off-by: Axe Yang <axe.yang@mediatek.com>
> > ---
> >  .../devicetree/bindings/mmc/mtk-sd.yaml       | 23
> > ++++++++++++++++++-
> >  1 file changed, 22 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> > b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> > index 297ada03e3de..f57774535a1d 100644
> > --- a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> > +++ b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml
> > @@ -69,12 +69,23 @@ properties:
> >        - const: ahb_cg
> >  
> >    interrupts:
> > -    maxItems: 1
> > +    description:
> > +      Should at least contain MSDC GIC interrupt. To support SDIO
> > in-band wakeup, an extended
> > +      interrupt is required and be configured as wakeup source
> > irq.
> > +    minItems: 1
> > +    maxItems: 2
> >  
> >    pinctrl-names:
> > +    description:
> > +      Should at least contain default and state_uhs. To support
> > SDIO in-band wakeup, dat1 pin
> > +      will be switched between GPIO mode and SDIO DAT1 mode,
> > state_eint and state_dat1 are
> > +      mandatory in this scenarios.
> > +    minItems: 2
> >      items:
> >        - const: default
> >        - const: state_uhs
> > +      - const: state_eint
> > +      - const: state_dat1
> >  
> >    pinctrl-0:
> >      description:
> > @@ -86,6 +97,16 @@ properties:
> >        should contain uhs mode pin ctrl.
> >      maxItems: 1
> >  
> > +  pinctrl-2:
> > +    description:
> > +      should switch dat1 pin to GPIO mode.
> > +    maxItems: 1
> > +
> > +  pinctrl-3:
> > +    description:
> > +      should switch SDIO dat1 pin from GPIO mode back to SDIO
> > mode.
> 
> How is this different than pinctrl-0?

pinctrl-0 contains default settings for all IO pins(CLK/CMD/DAT).
pinctrl-1 contains settings for all IO pins(CLK/CMD/DAT) in UHS mode.
pinctrl-3 is lightweight pinctrl-1, only keep SDIO DAT1 pin function
switch part.

...

Regards,
Axe