Re: [PATCH] arm64: dts: allwinner: a64: Add lradc node

From: luca
Date: Tue May 21 2019 - 09:55:29 EST


On May 21, 2019 3:09:55 PM GMT+02:00, Maxime Ripard <maxime.ripard@xxxxxxxxxxx> wrote:
>On Tue, May 21, 2019 at 08:43:45AM +0200, luca@xxxxxxxxx wrote:
>> On May 20, 2019 1:07:42 PM GMT+02:00, Maxime Ripard
><maxime.ripard@xxxxxxxxxxx> wrote:
>> >On Sat, May 18, 2019 at 07:09:30PM +0200, Luca Weiss wrote:
>> >> Add a node describing the KEYADC on the A64.
>> >>
>> >> Signed-off-by: Luca Weiss <luca@xxxxxxxxx>
>> >> ---
>> >> arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 7 +++++++
>> >> 1 file changed, 7 insertions(+)
>> >>
>> >> diff --git a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
>> >b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
>> >> index 7734f70e1057..dc1bf8c1afb5 100644
>> >> --- a/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
>> >> +++ b/arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi
>> >> @@ -704,6 +704,13 @@
>> >> status = "disabled";
>> >> };
>> >>
>> >> + lradc: lradc@1c21800 {
>> >> + compatible = "allwinner,sun4i-a10-lradc-keys";
>> >> + reg = <0x01c21800 0x100>;
>> >> + interrupts = <GIC_SPI 30 IRQ_TYPE_LEVEL_HIGH>;
>> >> + status = "disabled";
>> >> + };
>> >> +
>> >
>> >The controller is pretty different on the A64 compared to the A10.
>The
>> >A10 has two channels for example, while the A64 has only one.
>> >
>> >It looks like the one in the A83t though, so you can use that
>> >compatible instead.
>>
>> Looking at the patch for the A83t, the only difference is that it
>> uses a 3/4 instead of a 2/3 voltage divider, nothing is changed with
>> the channels.
>
>I guess you can reuse the A83t compatible here then, and a more
>specific a64 compatible in case we ever need to fix this.
>
>> But I'm also not sure which one (or a different one)
>> is used from looking at the "A64 User Manual".
>
>I'm sorry, what are you referring to with "one" in that sentence?
>
>Maxime
>
>--
>Maxime Ripard, Bootlin
>Embedded Linux and Kernel engineering
>https://bootlin.com

Hi,

Sorry, I meant I didn't find anything in the A64 user manual whether a 3/4 or a 2/3 voltage divider (or one with different values) is used on the A64.

Luca