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

[Tuomas Tynkkynen]

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.

- Tuomas