Re: [PATCH] arm64: dts: imx8mm-evk: add pwm1/backlight support

From: Tommaso Merciai
Date: Wed Apr 13 2022 - 08:40:42 EST


On Wed, Apr 13, 2022 at 02:27:00PM +0200, Krzysztof Kozlowski wrote:
> On 13/04/2022 13:58, Tommaso Merciai wrote:
> >>> + backlight: backlight {
> >>> + status = "disabled";
> >>
> >> Why disabled?
> >>
> >>> + compatible = "pwm-backlight";
> >>> + pwms = <&pwm1 0 5000000>;
> >>> + brightness-levels = <0 255>;
> >>> + num-interpolated-steps = <255>;
> >>> + default-brightness-level = <250>;
> >>> + };
> >>> +
> >>> ir-receiver {
> >>> compatible = "gpio-ir-receiver";
> >>> gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;
> >>> @@ -395,6 +404,12 @@ &wdog1 {
> >>> status = "okay";
> >>> };
> >>>
> >>> +&pwm1 {
> >>> + pinctrl-names = "default";
> >>> + pinctrl-0 = <&pinctrl_backlight>;
> >>> + status = "disabled";
> >>
> >> Same here.
> >>
> >>
> >> Best regards,
> >> Krzysztof
> >
> > Hi Krzysztof,
> > I think is better to keep disable into .dtsi and enable it at .dts
> > level.
> > What do you think about?
>
> Why better? This is already board DTSI, not a SoC DTSI. All boards using
> it are supposed to have it available, aren't they?
>
> Usually nodes should be disabled in a DTSI if they need some resources
> not available in that DTSI. For example if they need some supply. It's
> not the case here, right?

Hi Krzysztof,
Yes, right I check both schematics (DSI_BL_PWM). We can set PWM enable.
I'll update status in v2.

>
>
> Best regards,
> Krzysztof

Regards,
Tommaso

--
Tommaso Merciai
Embedded Linux Engineer
tommaso.merciai@xxxxxxxxxxxxxxxxxxxx
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