[PATCH 8/9] arm: dts: imx8mm_evk: add pwm1/backlight support

[Tommaso Merciai]

On Wed, Mar 16, 2022 at 12:54:06PM +0100, Michael Walle wrote:
> Am 2022-03-16 12:51, schrieb Tommaso Merciai:
> > On Wed, Mar 16, 2022 at 12:45:22PM +0100, Michael Walle wrote:
> > > Am 2022-03-16 12:42, schrieb Tommaso Merciai:
> > > > On Wed, Mar 16, 2022 at 11:30:19AM +0100, Michael Walle wrote:
> > > > > > Add pwm1/backlight support nodes for imx8mm_evk board
> > > > > >
> > > > > > Signed-off-by: Tommaso Merciai <tommaso.merciai at amarulasolutions.com>
> > > > > > ---
> > > > > >  arch/arm/dts/imx8mm-evk.dtsi | 21 +++++++++++++++++++++
> > > > > >  1 file changed, 21 insertions(+)
> > > > > >
> > > > > > diff --git a/arch/arm/dts/imx8mm-evk.dtsi b/arch/arm/dts/imx8mm-evk.dtsi
> > > > > > index 60179e006d..e7a2bd8a64 100644
> > > > > > --- a/arch/arm/dts/imx8mm-evk.dtsi
> > > > > > +++ b/arch/arm/dts/imx8mm-evk.dtsi
> > > > > > @@ -41,6 +41,15 @@
> > > > > >  		enable-active-high;
> > > > > >  	};
> > > > > >
> > > > > > +	backlight: backlight {
> > > > > > +		status = "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>;
> > > > > > @@ -350,6 +359,12 @@
> > > > > >  	status = "okay";
> > > > > >  };
> > > > > >
> > > > > > +&pwm1 {
> > > > > > +	pinctrl-names = "default";
> > > > > > +	pinctrl-0 = <&pinctrl_backlight>;
> > > > > > +	status = "disabled";
> > > > > > +};
> > > > > > +
> > > > > >  &iomuxc {
> > > > > >  	pinctrl_fec1: fec1grp {
> > > > > >  		fsl,pins = <
> > > > > > @@ -491,4 +506,10 @@
> > > > > >  			MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B	0x166
> > > > > >  		>;
> > > > > >  	};
> > > > > > +
> > > > > > +	pinctrl_backlight: backlightgrp {
> > > > > > +		fsl,pins = <
> > > > > > +			MX8MM_IOMUXC_GPIO1_IO01_PWM1_OUT	0x06
> > > > > > +		>;
> > > > > > +	};
> > > > >
> > > > > Will this also be submitted to upstream linux? Otherwise, the device
> > > > > trees will diverge.
> > > > >
> > > > > -michael
> > > >
> > > > Hi,
> > > > At the moment on upstream linux, backlight on pwm1 is not handle. This
> > > > will also be submitted on upstream Linux once will merged on U-Boot.
> > > 
> > > Actually, it should be the other way around, because the device trees
> > > should be synced with linux once in a while. So while I don't oppose
> > > to do it this way, your changes might eventually be overwritten if
> > > this won't be merged with linux.
> > > 
> > > -michael
> > 
> > Hi Michael,
> > Then you suggest to submit to the Kernel also?
> 
> The goal should be to have the kernel device trees in sync with
> the kernel. So yes, it should also be submitted to the kernel
> device tree.
> 
> -michael

Hi Michael,
Thanks for your suggestion, then I will also send this on the Kernel :)

Tommaso
-- 
Tommaso Merciai
Embedded Linux Engineer
tommaso.merciai at amarulasolutions.com
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