Re: [PATCH v1 1/1] arm64: dts: qcom: talos-evk: Add support for dual-channel LVDS panel
From: Dmitry Baryshkov
Date: Wed Oct 29 2025 - 08:35:02 EST
On Wed, Oct 29, 2025 at 05:50:01PM +0530, Tessolve Upstream wrote:
>
>
> On 28/10/25 14:55, Konrad Dybcio wrote:
> > On 10/28/25 7:16 AM, Sudarshan Shetty wrote:
> >> This patch introduces a new device tree for the QCS615 Talos
> >> EVK platform with dual-channel LVDS display support.
> >>
> >> The new DTS file (`talos-evk-lvds.dts`) is based on the existing
> >> `talos-evk.dts` and extends it to enable a dual-channel LVDS display
> >> configuration using the TI SN65DSI84 DSI-to-LVDS bridge.
> >>
> >> where channel-A carries odd pixel and channel-B carries even pixel
> >> on the QCS615 talos evk platform.
> >>
> >> Signed-off-by: Sudarshan Shetty <tessolveupstream@xxxxxxxxx>
> >> ---
> >
> > [...]
> >
> >> + backlight: backlight {
> >> + compatible = "gpio-backlight";
> >> + gpios = <&tlmm 115 GPIO_ACTIVE_HIGH>;
> >> + default-on;
> >> + };
> >> +
> >> + lcd0_pwm_en {
> >
> > Use hyphens instead of underscores in node names
>
> Okay, will update in next patch.
> >
> >> + compatible = "pwm-gpio";
> >> + gpios = <&tlmm 59 GPIO_ACTIVE_HIGH>;
> >> + pinctrl-0 = <&lcd0_bklt_pwm>;
> >
> > I think your intention was to use pwm-backlight and wire this node
> > up to that
>
> Soc does not support the PWM interface hence we are using gpio
> as "pwm-gpio" by setting the duty cycle to 100%(i.e. "no pwm")
Why do you mention PWM here at all? It's perfectly fine to use
gpio-backlight. That looks extremely suspicious since you are not
referecing the pwm-gpio device at all.
--
With best wishes
Dmitry