[PATCH] arm64: dts: rockchip: Remove non-existing pwm-delay-us DT property

[PATCH] arm64: dts: rockchip: Remove non-existing pwm-delay-us DT property

[Javier Martinez Canillas]

There is no neither a driver that parses this nor a DT binding schema that
documents it so let's remove it from the DTS files that make use of this.

The properties that exist are post-pwm-on-delay-ms and pwm-off-delay-ms,
defined in the pwm-backlight DT binding. So probably what these DTS want
is something like following:

        backlight: backlight {
                compatible = "pwm-backlight";
                enable-gpios = <&gpio4 21 GPIO_ACTIVE_HIGH>;
                pinctrl-names = "default";
                pinctrl-0 = <&bl_en>;
                pwms = <&pwm1 0 1000000 0>;
                post-pwm-on-delay-ms = <10>;
                pwm-off-delay-ms = <10>;
        };

But that should be follow-up change if that is the case. Because otherwise
it would be change in behaviour, since currently pwm-delay-us is a no-op.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
---

 arch/arm64/boot/dts/rockchip/rk3368-evb.dtsi            | 1 -
 arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi | 1 -
 arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi    | 1 -
 3 files changed, 3 deletions(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3368-evb.dtsi b/arch/arm64/boot/dts/rockchip/rk3368-evb.dtsi
index 083452c67711..e47d1398aeca 100644
--- a/arch/arm64/boot/dts/rockchip/rk3368-evb.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3368-evb.dtsi
@@ -61,7 +61,6 @@ backlight: backlight {
 		pinctrl-names = "default";
 		pinctrl-0 = <&bl_en>;
 		pwms = <&pwm0 0 1000000 PWM_POLARITY_INVERTED>;
-		pwm-delay-us = <10000>;
 	};
 
 	emmc_pwrseq: emmc-pwrseq {
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi
index ee6095baba4d..5c1929d41cc0 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399-gru-chromebook.dtsi
@@ -198,7 +198,6 @@ backlight: backlight {
 		power-supply = <&pp3300_disp>;
 		pinctrl-names = "default";
 		pinctrl-0 = <&bl_en>;
-		pwm-delay-us = <10000>;
 	};
 
 	gpio_keys: gpio-keys {
diff --git a/arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi
index a47d9f758611..c5e7de60c121 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3399-gru-scarlet.dtsi
@@ -167,7 +167,6 @@ backlight: backlight {
 		pinctrl-names = "default";
 		pinctrl-0 = <&bl_en>;
 		pwms = <&pwm1 0 1000000 0>;
-		pwm-delay-us = <10000>;
 	};
 
 	dmic: dmic {

base-commit: ffe78bbd512166e0ef1cc4858010b128c510ed7d
prerequisite-patch-id: ab73fde77786baf8fa44882125c5ce864771371c
-- 
2.40.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH] arm64: dts: rockchip: Remove non-existing pwm-delay-us DT property

[Brian Norris]

On Thu, Mar 30, 2023 at 3:03 PM Javier Martinez Canillas
<javierm@redhat.com> wrote:
>
> There is no neither a driver that parses this nor a DT binding schema that
> documents it so let's remove it from the DTS files that make use of this.
>
> The properties that exist are post-pwm-on-delay-ms and pwm-off-delay-ms,
> defined in the pwm-backlight DT binding. So probably what these DTS want
> is something like following:
>
>         backlight: backlight {
>                 compatible = "pwm-backlight";
>                 enable-gpios = <&gpio4 21 GPIO_ACTIVE_HIGH>;
>                 pinctrl-names = "default";
>                 pinctrl-0 = <&bl_en>;
>                 pwms = <&pwm1 0 1000000 0>;
>                 post-pwm-on-delay-ms = <10>;
>                 pwm-off-delay-ms = <10>;
>         };
>
> But that should be follow-up change if that is the case. Because otherwise
> it would be change in behaviour, since currently pwm-delay-us is a no-op.
>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>

pwm-delay-us seems to have been a downstream-only ("CHROMIUM", if
you're familiar with ChromiumOS kernel parlance) change that seems
like a combination of the two now-upstream properties you point at. I
looked through the first use of pwm-delay-us on RK3399 Gru systems,
and I can't find a spec reference that said it was needed; perhaps it
was needless copy/paste imitation?

So, simple deletion is probably fine:

Reviewed-by: Brian Norris <briannorris@chromium.org>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH] arm64: dts: rockchip: Remove non-existing pwm-delay-us DT property

[Javier Martinez Canillas]

Brian Norris <briannorris@chromium.org> writes:

Hello Brian,

> On Thu, Mar 30, 2023 at 3:03 PM Javier Martinez Canillas
> <javierm@redhat.com> wrote:
>>
>> There is no neither a driver that parses this nor a DT binding schema that

Ups, I noticed now that there's an unnecessary "no" and it should be instead:

"There is neither a driver..."

>> documents it so let's remove it from the DTS files that make use of this.
>>
>> The properties that exist are post-pwm-on-delay-ms and pwm-off-delay-ms,
>> defined in the pwm-backlight DT binding. So probably what these DTS want
>> is something like following:
>>
>>         backlight: backlight {
>>                 compatible = "pwm-backlight";
>>                 enable-gpios = <&gpio4 21 GPIO_ACTIVE_HIGH>;
>>                 pinctrl-names = "default";
>>                 pinctrl-0 = <&bl_en>;
>>                 pwms = <&pwm1 0 1000000 0>;
>>                 post-pwm-on-delay-ms = <10>;
>>                 pwm-off-delay-ms = <10>;
>>         };
>>
>> But that should be follow-up change if that is the case. Because otherwise
>> it would be change in behaviour, since currently pwm-delay-us is a no-op.
>>
>> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
>
> pwm-delay-us seems to have been a downstream-only ("CHROMIUM", if
> you're familiar with ChromiumOS kernel parlance) change that seems
> like a combination of the two now-upstream properties you point at. I

Yes, that's what I found too. So it seems that this was an oversight when
the DTS for these Chromebooks were upstreamed.

> looked through the first use of pwm-delay-us on RK3399 Gru systems,
> and I can't find a spec reference that said it was needed; perhaps it
> was needless copy/paste imitation?
>
> So, simple deletion is probably fine:
>
> Reviewed-by: Brian Norris <briannorris@chromium.org>
>

Thanks for the confirmation and review!

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel