2021-11-21 23:58:16

by Prabhakar Mahadev Lad

[permalink] [raw]
Subject: [PATCH] arm64: dts: hihope-rzg2-ex-lvds: Add power-supply and enable-gpios to backlight node

This patch adds missing power-supply and enable-gpios property to
backlight node. This fixes the warning "pwm-backlight backlight:
backlight supply power not found, using dummy regulator".

Signed-off-by: Lad Prabhakar <[email protected]>
---
arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi b/arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi
index 40c5e8d6d841..a4fb8582a36b 100644
--- a/arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi
+++ b/arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi
@@ -12,6 +12,17 @@

brightness-levels = <0 2 8 16 32 64 128 255>;
default-brightness-level = <6>;
+ power-supply = <&reg_12v>;
+ enable-gpios = <&gpio6 7 GPIO_ACTIVE_HIGH>;
+ };
+
+ reg_12v: regulator2 {
+ compatible = "regulator-fixed";
+ regulator-name = "fixed-12V";
+ regulator-min-microvolt = <12000000>;
+ regulator-max-microvolt = <12000000>;
+ regulator-boot-on;
+ regulator-always-on;
};
};

--
2.17.1



2021-11-23 14:44:54

by Geert Uytterhoeven

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Subject: Re: [PATCH] arm64: dts: hihope-rzg2-ex-lvds: Add power-supply and enable-gpios to backlight node

Hi Prabhakar,

On Mon, Nov 22, 2021 at 12:58 AM Lad Prabhakar
<[email protected]> wrote:
> This patch adds missing power-supply and enable-gpios property to
> backlight node. This fixes the warning "pwm-backlight backlight:
> backlight supply power not found, using dummy regulator".
>
> Signed-off-by: Lad Prabhakar <[email protected]>

Thanks for your patch!

> --- a/arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi
> +++ b/arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi
> @@ -12,6 +12,17 @@
>
> brightness-levels = <0 2 8 16 32 64 128 255>;
> default-brightness-level = <6>;
> + power-supply = <&reg_12v>;
> + enable-gpios = <&gpio6 7 GPIO_ACTIVE_HIGH>;

According to the schematics (up to Rev. 4.00), GP6_07 is not connected?

> + };
> +
> + reg_12v: regulator2 {

Using "regulatorN" as a node name is error-prone, and may lead to
accidental clashes. Please use a more appropriate name.

> + compatible = "regulator-fixed";
> + regulator-name = "fixed-12V";
> + regulator-min-microvolt = <12000000>;
> + regulator-max-microvolt = <12000000>;

Hmm, the AT1316A is a constant-current source, not a constant-voltage
source? The -02 variant has a 0.2V Low Reference Voltage. Combined
with the 1.1Ω resistor, that should give 181818 microamp.

> + regulator-boot-on;
> + regulator-always-on;
> };
> };

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds

2021-11-23 20:19:26

by Lad, Prabhakar

[permalink] [raw]
Subject: Re: [PATCH] arm64: dts: hihope-rzg2-ex-lvds: Add power-supply and enable-gpios to backlight node

Hi Geert,

Thank you for the review.

On Tue, Nov 23, 2021 at 2:44 PM Geert Uytterhoeven <[email protected]> wrote:
>
> Hi Prabhakar,
>
> On Mon, Nov 22, 2021 at 12:58 AM Lad Prabhakar
> <[email protected]> wrote:
> > This patch adds missing power-supply and enable-gpios property to
> > backlight node. This fixes the warning "pwm-backlight backlight:
> > backlight supply power not found, using dummy regulator".
> >
> > Signed-off-by: Lad Prabhakar <[email protected]>
>
> Thanks for your patch!
>
> > --- a/arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi
> > +++ b/arch/arm64/boot/dts/renesas/hihope-rzg2-ex-lvds.dtsi
> > @@ -12,6 +12,17 @@
> >
> > brightness-levels = <0 2 8 16 32 64 128 255>;
> > default-brightness-level = <6>;
> > + power-supply = <&reg_12v>;
> > + enable-gpios = <&gpio6 7 GPIO_ACTIVE_HIGH>;
>
> According to the schematics (up to Rev. 4.00), GP6_07 is not connected?
>
Ouch sorry about that. When I noticed a warning with the regulator, I
saw the missing gpio property too and I pulled out the older schematic
with Rev2 which has GP6_07 :(
> > + };
> > +
> > + reg_12v: regulator2 {
>
> Using "regulatorN" as a node name is error-prone, and may lead to
> accidental clashes. Please use a more appropriate name.
>
> > + compatible = "regulator-fixed";
> > + regulator-name = "fixed-12V";
> > + regulator-min-microvolt = <12000000>;
> > + regulator-max-microvolt = <12000000>;
>
> Hmm, the AT1316A is a constant-current source, not a constant-voltage
> source? The -02 variant has a 0.2V Low Reference Voltage. Combined
> with the 1.1Ω resistor, that should give 181818 microamp.
>
Agreed.

Cheers,
Prabhakar

> > + regulator-boot-on;
> > + regulator-always-on;
> > };
> > };
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
> -- Linus Torvalds