[PATCH] arm64: dts: qcom: sc7180: Assign numbers to eMMC and SD

[PATCH] arm64: dts: qcom: sc7180: Assign numbers to eMMC and SD

[Douglas Anderson]

After many years of struggle, commit fa2d0aa96941 ("mmc: core: Allow
setting slot index via device tree alias") finally allows the use of
aliases to number SD/MMC slots.  Let's do that for sc7180 SoCs so that
if eMMC and SD are both used they have consistent numbers across boots
and kernel changes.

Picking numbers can be tricky.  Do we call these "1" and "2" to match
the name in documentation or "0" and "1" with the assertion that we
should always start at 0 and count up?

While the "start counting at 0" makes sense if there are not already
well-defined numbers for all sd/mmc controllers, in the case of sc7180
there _are_ well defined numbers.  IMO it is less confusing to use
those and match the docs.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 arch/arm64/boot/dts/qcom/sc7180.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
index 4e7e58c63285..625e922c273d 100644
--- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
@@ -31,6 +31,8 @@ / {
 	chosen { };
 
 	aliases {
+		mmc1 = &sdhc_1;
+		mmc2 = &sdhc_2;
 		i2c0 = &i2c0;
 		i2c1 = &i2c1;
 		i2c2 = &i2c2;
-- 
2.29.2.222.g5d2a92d10f8-goog

Re: [PATCH] arm64: dts: qcom: sc7180: Assign numbers to eMMC and SD

[Bjorn Andersson]

On Wed 11 Nov 09:37 CST 2020, Douglas Anderson wrote:

> After many years of struggle, commit fa2d0aa96941 ("mmc: core: Allow
> setting slot index via device tree alias") finally allows the use of
> aliases to number SD/MMC slots.  Let's do that for sc7180 SoCs so that
> if eMMC and SD are both used they have consistent numbers across boots
> and kernel changes.
> 
> Picking numbers can be tricky.  Do we call these "1" and "2" to match
> the name in documentation or "0" and "1" with the assertion that we
> should always start at 0 and count up?
> 
> While the "start counting at 0" makes sense if there are not already
> well-defined numbers for all sd/mmc controllers, in the case of sc7180
> there _are_ well defined numbers.  IMO it is less confusing to use
> those and match the docs.
> 

I'm happy with this motivation, patch applied.

Regards,
Bjorn

> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> 
>  arch/arm64/boot/dts/qcom/sc7180.dtsi | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
> index 4e7e58c63285..625e922c273d 100644
> --- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
> @@ -31,6 +31,8 @@ / {
>  	chosen { };
>  
>  	aliases {
> +		mmc1 = &sdhc_1;
> +		mmc2 = &sdhc_2;
>  		i2c0 = &i2c0;
>  		i2c1 = &i2c1;
>  		i2c2 = &i2c2;
> -- 
> 2.29.2.222.g5d2a92d10f8-goog
>