On Fri, May 09, 2025 at 03:32:04PM +0100, Andre Przywara wrote: > On Wed, 7 May 2025 15:19:42 -0500 > Chris Morgan <macroalph...@gmail.com> wrote: > > Hi Chris, > > > From: Chris Morgan <macromor...@hotmail.com> > > > > The LCD backlight for this device can be exposed as a simple GPIO- > > controlled device. It would be more accurately modelled using PWM to > > enable brightness control, however the PWM driver design for the H616 is > > not yet upstreamed. > > I don't think this is right then: First there should be no notion of a > "driver being upstreamed" in a *DT* patch, as "the driver" is a Linux > speciality, which the DT itself doesn't care about. > And secondly we should not chicken out and go with an interim solution. > > So I guess we need to wait for the PWM binding to appear. > > Cheers, > Andre
Okay, so then I can drop the backlight (and might as well drop the LCD bindings as well) until the PWM is upstreamed. I just figured "something" for now is okay, but we can wait. This is the specific series I'm tracking [1]... adding support for the H616 would just require a little bit of boilerplate code and a new compatible string once that gets upstreamed. [1] https://lore.kernel.org/linux-sunxi/20250427142500.151925-3-privates...@gmail.com/ Thank you, Chris > > > Add a GPIO backlight node to the DTS. > > > > Signed-off-by: Ryan Walklin <r...@testtoast.com> > > Signed-off-by: Chris Morgan <macromor...@hotmail.com> > > --- > > .../boot/dts/allwinner/sun50i-h700-anbernic-rg35xx-2024.dts | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git > > a/arch/arm64/boot/dts/allwinner/sun50i-h700-anbernic-rg35xx-2024.dts > > b/arch/arm64/boot/dts/allwinner/sun50i-h700-anbernic-rg35xx-2024.dts > > index 7e17ca07892d..95f2ae04bd95 100644 > > --- a/arch/arm64/boot/dts/allwinner/sun50i-h700-anbernic-rg35xx-2024.dts > > +++ b/arch/arm64/boot/dts/allwinner/sun50i-h700-anbernic-rg35xx-2024.dts > > @@ -21,6 +21,12 @@ aliases { > > serial0 = &uart0; > > }; > > > > + backlight: backlight { > > + compatible = "gpio-backlight"; > > + gpios = <&pio 3 28 GPIO_ACTIVE_HIGH>; // PD28 > > + default-on; > > + }; > > + > > battery: battery { > > compatible = "simple-battery"; > > constant-charge-current-max-microamp = <1024000>; >
