On Montag, 3. Juni 2019 09:42:47 CEST Maxime Ripard wrote:
> Hi,
> 
> On Fri, May 31, 2019 at 12:27:55PM +0200, Luca Weiss wrote:
> > On Freitag, 24. Mai 2019 11:20:01 CEST Maxime Ripard wrote:
> > > It would be great to drop the -keys from the compatible, and to
> > > document the bindings
> > > 
> > > Looks good otherwise
> > > 
> > > Maxime
> > 
> > So I should just document the "allwinner,sun50i-a64-lradc" string in
> > Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt ? Don't I
> > also
> > have to add the compatible to the driver code then? Just adding the a64
> > compatible to a dts wouldn't work without that.
> 
> What I meant was that you needed both, something like:
> 
> compatible = "allwinner,sun50i-a64-lradc", "allwinner,sun8i-a83t-lradc";
> 
> That way, the OS will try to match a driver for the A64 compatible if
> any, and fallback to the A83's otherwise. And since we don't have any
> quirk at the moment, there's no change needed to the driver.
> 
> Maxime
> 
> --
> Maxime Ripard, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com

Hi Maxime,
sorry for the long back and forth, I hope I understood you correctly now.
Here's what I would submit as v2 then (I'll split the two files into seperate 
patches as the devicetree documentation suggests)

Documentation/devicetree/bindings/input/sun4i-lradc-keys.txt:
  - compatible: should be one of the following string:
                "allwinner,sun4i-a10-lradc-keys"
                "allwinner,sun8i-a83t-r-lradc"
+               "allwinner,sun50i-a64-lradc", "allwinner,sun8i-a83t-r-lradc"

arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi:
+               lradc: lradc@1c21800 {
+                       compatible = "allwinner,sun50i-a64-lradc",
+                                    "allwinner,sun8i-a83t-r-lradc";
+                       reg = <0x01c21800 0x400>;
+                       interrupts = <GIC_SPI 30 IRQ_TYPE_LEVEL_HIGH>;
+                       status = "disabled";
+               };
+

Thanks,
Luca