Re: [PATCH] arm64: dts: rockchip: move backlight from sapphire to excavator

Vicente Bergas
2018-10-30T17:19:50Z

On Tue, Oct 30, 2018 at 5:59 PM Enric Balletbo Serra
<eballetbo@gmail.com> wrote:
>
> Hi Vicente,
>
> Missatge de Vicente Bergas <vicencb@gmail.com> del dia dt., 30 d’oct.
> 2018 a les 16:21:
> >
> > The backlight is for the eDP panel and it has the connector on the excavator baseboard.
> >
> > Signed-off-by: Vicente Bergas <vicencb@gmail.com>
> > ---
> > .../rockchip/rk3399-sapphire-excavator.dts | 46 +++++++++++++++++--
> > .../boot/dts/rockchip/rk3399-sapphire.dtsi | 39 ----------------
> > 2 files changed, 41 insertions(+), 44 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dts b/arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dts
> > index fef2c0608..0b8f1edbd 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dts
> > +++ b/arch/arm64/boot/dts/rockchip/rk3399-sapphire-excavator.dts
> > @@ -42,6 +42,47 @@
> > };
> > };
> >
> > + backlight: backlight {
> > + compatible = "pwm-backlight";
> > + brightness-levels = <
> > + 0 1 2 3 4 5 6 7
...
> > + 248 249 250 251 252 253 254 255>;
> > + default-brightness-level = <200>;
>
> Could you try if just removing the brightness-level table and
> default-brightness-level properties gives you a good backlight
> experience?
>
> After commit 88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED
> linearly to human eye") the pwm_bl driver is able to calculate a default
> brightness table. The calculated table for this PWM will have more
> granularity and will be adjusted to change the brightness linearly to
> the human eye.
>
> If it works maybe we can just get rid of this awful brightness-table.

I have tested that it does not break the Sapphire daugther-board,
but have no Excavator base-board to test, i have just checked that
the resulting decompiled dtb is equivalent.

Regards,
Vicenç.

> Best regards,
> Enric
>
> > + enable-gpios = <&gpio1 RK_PB5 GPIO_ACTIVE_HIGH>;
> > + pwms = <&pwm0 0 25000 0>;
> > + status = "okay";
> > + };
> > +
> > edp_panel: edp-panel {
> > compatible ="lg,lp079qx1-sp0v", "simple-panel";
> > backlight = <&backlight>;
> > @@ -95,11 +136,6 @@
> > };
> > };
> >
> > -&backlight {
> > - enable-gpios = <&gpio1 RK_PB5 GPIO_ACTIVE_HIGH>;
> > - status = "okay";
> > -};
> > -
> > &edp {
> > status = "okay";
> >
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi b/arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi
> > index 2eb6489d4..6ce5a42c9 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi
> > +++ b/arch/arm64/boot/dts/rockchip/rk3399-sapphire.dtsi
> > @@ -15,45 +15,6 @@
> > stdout-path = "serial2:1500000n8";
> > };
> >
> > - backlight: backlight {
> > - compatible = "pwm-backlight";
> > - brightness-levels = <
> > - 0 1 2 3 4 5 6 7
...
> > - 248 249 250 251 252 253 254 255>;
> > - default-brightness-level = <200>;
> > - pwms = <&pwm0 0 25000 0>;
> > - };
> > -
> > clkin_gmac: external-gmac-clock {
> > compatible = "fixed-clock";
> > clock-frequency = <125000000>;
> > --
> > 2.19.1
> >
> >
> > _______________________________________________
> > Linux-rockchip mailing list
> > Linux-rockchip@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-rockchip