[PATCH v2] arm64: dts: allwinner: Revert SD card CD GPIO for Pine64-LTS

[Michael Weiser]

Hi Andre,

On Wed, Apr 14, 2021 at 11:47:40AM +0100, Andre Przywara wrote:

> Commit 941432d00768 ("arm64: dts: allwinner: Drop non-removable from
> SoPine/LTS SD card") enabled the card detect GPIO for the SOPine module,
> along the way with the Pine64-LTS, which share the same base .dtsi.

> This was based on the observation that the Pine64-LTS has as "push-push"
> SD card socket, and that the schematic mentions the card detect GPIO.

> After having received two reports about failing SD card access with that
> patch, some more research and polls on that subject revealed that there
> are at least two different versions of the Pine64-LTS out there:
> - On some boards (including mine) the card detect pin is "stuck" at
>   high, regardless of an microSD card being inserted or not.
> - On other boards the card-detect is working, but is active-high, by
>   virtue of an explicit inverter circuit, as shown in the schematic.

> To cover all versions of the board out there, and don't take any chances,
> let's revert the introduction of the active-low CD GPIO, but let's use
> the broken-cd property for the Pine64-LTS this time. That should avoid
> regressions and should work for everyone, even allowing SD card changes
> now.
> The SOPine card detect has proven to be working, so let's keep that
> GPIO in place.

I can confirm that this change works on my Pine64 LTS boards (with
working high-active card detect) when applied to today's linux-next (which
already includes your previous change to change the card detect GPIO
from low- to high-active in sun50i-a64-sopine.dtsi).

> Fixes: 941432d00768 ("arm64: dts: allwinner: Drop non-removable from SoPine/LTS SD card")
> Reported-by: Michael Weiser <michael.weiser at gmx.de>
> Reported-by: Daniel Kulesz <kuleszdl at posteo.org>
> Suggested-by: Chen-Yu Tsai <wens at csie.org>
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>

Tested-by: Michael Weiser <michael.weiser at gmx.de>

Thanks!
Michael

> ---
>  arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts b/arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts
> index e79ce49e7e6a..596a25907432 100644
> --- a/arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts
> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64-pine64-lts.dts
> @@ -21,5 +21,5 @@
>  };

>  &mmc0 {
> -	cd-gpios = <&pio 5 6 GPIO_ACTIVE_LOW>; /* PF6 push-push switch */
> +	broken-cd;		/* card detect is broken on *some* boards */
>  };

-- 
tschoe, Michael
Eisregen