Hi Ulrich,
On Thu, Apr 27, 2017 at 4:37 PM, Ulrich Hecht
<ulrich.hecht+renesas@xxxxxxxxx> wrote:
> The panel backlight is controlled through a GPIO and a PWM channel.
>
> Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@xxxxxxxxx>
> ---
> arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dts | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dts b/arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dts
> index 14d9e51..abda84c 100644
> --- a/arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dts
> +++ b/arch/arm64/boot/dts/renesas/r8a7796-salvator-x.dts
> @@ -133,6 +133,11 @@
> function = "i2c2";
> };
>
> + pwm1_pins: pwm {
> + groups = "pwm1_a";
> + function = "pwm1";
> + };
> +
> sdhi0_pins: sd0 {
> groups = "sdhi0_data4", "sdhi0_ctrl";
> function = "sdhi0";
> @@ -183,6 +188,16 @@
> interrupt-parent = <&gpio2>;
> interrupts = <11 IRQ_TYPE_LEVEL_LOW>;
> };
> +
> + backlight: backlight {
> + compatible = "pwm-backlight";
> + pwms = <&pwm1 0 50000>;
> +
> + brightness-levels = <256 128 64 16 8 4 0>;
> + default-brightness-level = <6>;
> +
> + enable-gpios = <&gpio6 7 GPIO_ACTIVE_HIGH>;
> + };
> };
This prints the following warning:
pwm-backlight backlight: backlight supply power not found, using dummy regulator
According to Documentation/devicetree/bindings/leds/backlight/pwm-backlight.txt,
the "power-supply" property is required.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
