[U-Boot] [PATCH] ARM: dts: logicpd-torpedo-37xx-devkit-u-boot: Fix MMC Card Detect

[Adam Ford]

On Wed, Sep 5, 2018 at 8:08 AM Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi> wrote:
>
> Hi Adam,
>
> On 09/03/2018 05:08 PM, Adam Ford wrote:
> > When re-syncing the DTS files from the kernel, something caused
> > the MMC driver to no longer detect the MMC card. Undoing the
> > CD-invert appears to fix the issue.
> >
> > Fixes: e6ea2390cde3 ("ARM: DTS: Resync LogicPD-Torpedo-37xx-devkit
> > with Linux 4.18-RC4")
> >
>
> Looking at that commit, we see:
>
> -       cd-gpios = <&gpio4 31 IRQ_TYPE_LEVEL_LOW>;              /* gpio127 */
> +       cd-gpios = <&gpio4 31 GPIO_ACTIVE_LOW>;         /* gpio127 */
>
>
> IRQ_TYPE_LEVEL_LOW is defined as 8, which in this context should get
> interpreted as GPIO_TRANSITORY which is ignored by U-Boot. Thus the
> card-detect polarity got toggled by that commit.
>
> If ACTIVE_LOW is indeed the correct polarity (and I'm guessing it
> is because otherwise MMC wouldn't work in Linux), this patch sounds
> correct.

That makes a lot of sense.  Thanks for that.

adam
>
> - Tuomas