Re: [PATCH 2/3] ARM: dts: sun5i: Add port E pinmux settings for mmc2

From: Jonathan McDowell
Date: Thu Apr 20 2023 - 15:13:36 EST


On Sun, Apr 16, 2023 at 01:47:56AM +0100, Andre Przywara wrote:
> On Sat, 15 Apr 2023 18:46:24 +0100
> Jonathan McDowell <noodles@xxxxxxxx> wrote:
>
> Hi,
>
> > These alternate pins for mmc2 are brought out to the 40 pin U14 header
> > on the C.H.I.P and can be used to add an external MMC device with a 4
> > bit interface. See
> >
> > https://byteporter.com/ntc-chip-micro-sd-slot/
> >
> > for further details on how.
> >
> > Signed-off-by: Jonathan McDowell <noodles@xxxxxxxx>
> > ---
> > arch/arm/boot/dts/sun5i.dtsi | 8 ++++++++
> > 1 file changed, 8 insertions(+)
> >
> > diff --git a/arch/arm/boot/dts/sun5i.dtsi b/arch/arm/boot/dts/sun5i.dtsi
> > index 250d6b87ab4d..e4922506ce22 100644
> > --- a/arch/arm/boot/dts/sun5i.dtsi
> > +++ b/arch/arm/boot/dts/sun5i.dtsi
> > @@ -517,6 +517,14 @@ mmc2_4bit_pc_pins: mmc2-4bit-pc-pins {
> > bias-pull-up;
> > };
> >
>
> As this seems to be a highly non-standard and rare modification, that
> doesn't even get used in the mainline DT, please add a:
> /omit-if-no-ref/
> line, so we don't get this into every sun5i board.

Neat, will add in v2.

> Otherwise looks good, though I don't know if that should belong into
> the same DT overlay that is probably used to also enable the MMC2 node.

I pondered that, but we already have the mmc2-4bit-pc-pins definition
here so it seemed helpful to add the pe-pins too.

> > + mmc2_4bit_pe_pins: mmc2-4bit-pe-pins {
> > + pins = "PE4", "PE5", "PE6", "PE7",
> > + "PE8", "PE9";
> > + function = "mmc2";
> > + drive-strength = <30>;
> > + bias-pull-up;
> > + };
> > +
> > mmc2_8bit_pins: mmc2-8bit-pins {
> > pins = "PC6", "PC7", "PC8", "PC9",
> > "PC10", "PC11", "PC12", "PC13",
>

J.

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