Re: [PATCHv3 5/7] ARM: dts: exynos5422: use wp-gpio method to detect sd-card

From: Anand Moon <linux.amoon@gmail.com>
To: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Kukjin Kim <kgene@kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Jaehoon Chung <jh80.chung@samsung.com>,
	Ulf Hansson <ulf.hansson@linaro.org>,
	devicetree <devicetree@vger.kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	linux-samsung-soc@vger.kernel.org,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	linux-mmc@vger.kernel.org
Subject: Re: [PATCHv3 5/7] ARM: dts: exynos5422: use wp-gpio method to detect sd-card
Date: Fri, 21 Sep 2018 18:01:07 +0530	[thread overview]
Message-ID: <CANAwSgQQgObh-N0CbBM9iNxOGUd2uwoKNFVDBymEALzMtHxOhA@mail.gmail.com> (raw)
In-Reply-To: <CAJKOXPdUVjG1xR-q-K98RQpqsWzw-emEv2_3x3CoS+XK8cye2Q@mail.gmail.com>

Hi Krzysztof,

On Fri, 21 Sep 2018 at 16:42, Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On Thu, 20 Sep 2018 at 19:59, Anand Moon <linux.amoon@gmail.com> wrote:
> >
> > add the Write Protect GPIO property for sdcard, to fix
> > the warning message during boot time.
> > of_get_named_gpiod_flags: can't parse 'wp-gpios' property of node '/soc/mmc@12220000[0]'
> >
> > Signed-off-by: Anand Moon <linux.amoon@gmail.com>
> > ---
> > New patch to this series.
> > If we keep the wp-gpio GPIO_ACTIVE_LOW sdcard boot into RO mode.
> > ---
> >  arch/arm/boot/dts/exynos5422-odroid-core.dtsi | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
> > index 03fe02ceae66..475c38bbc99e 100644
> > --- a/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
> > +++ b/arch/arm/boot/dts/exynos5422-odroid-core.dtsi
> > @@ -370,6 +370,7 @@
> >         cap-sd-highspeed;
> >         max-frequency = <200000000>;
> >         cd-gpios = <&gpc2 2 GPIO_ACTIVE_LOW>;
> > +       wp-gpios = <&gpc4 0 GPIO_ACTIVE_HIGH>;
>
> Two issues here:
> 1. You need also proper pinctrl setting.

Thanks for pointing out. Yes proper pinctrl is needed to support this setting.
probably pinctrl sd2_wp is needed to support this feature.

> 2. On schematics the WP is not connected... so how do you know that it
From XU4_MAIN_REV0.1 schematics page 7 "Micro Socket" their is no
connection to WP pin.
but below schematics page "EXYNOS 5422 MMC UFS" it's shows
XMMC2WP/GPC4_0/EXT_INT13_0.

> is active high? How did you test it? How do you want to test it on
> microSD?

I just tested this with the DTS change to GPIO_ACTIVE_LOW which
resulted the microSD card booted into RO mode.
So I set this to GPIO_ACTIVE_HIGH just to avoid warning.

I will study the changes requires and then post proper separate patch
to support this feature.

Best Regards
-Anand
>
> Best regards,
> Krzysztof
>
> >         vmmc-supply = <&ldo19_reg>;
> >         vqmmc-supply = <&ldo13_reg>;
> >         sd-uhs-sdr50;
> > --
> > 2.17.1
> >