Re: [PATCH v5 13/13] video: backlight: mt6370: Add MediaTek MT6370 support

[AngeloGioacchino Del Regno]

Il 15/07/22 13:26, ChiaEn Wu ha scritto:
> From: ChiaEn Wu <chiaen_wu@xxxxxxxxxxx>
>
> MediaTek MT6370 is a SubPMIC consisting of a single cell battery charger
> with ADC monitoring, RGB LEDs, dual channel flashlight, WLED backlight
> driver, display bias voltage supply, one general purpose LDO, and the
> USB Type-C & PD controller complies with the latest USB Type-C and PD
> standards.
>
> This adds support for MediaTek MT6370 Backlight driver. It's commonly used
> to drive the display WLED. There are 4 channels inside, and each channel
> supports up to 30mA of current capability with 2048 current steps in
> exponential or linear mapping curves.
>
> Signed-off-by: ChiaEn Wu <chiaen_wu@xxxxxxxxxxx>

Hello ChiaEn,

I propose to move this one to drivers/leds (or drivers/pwm) and, instead of
registering a backlight device, register a PWM device.

This way you will be able to reuse the generic backlight-pwm driver, as you'd
be feeding the PWM device exposed by this driver to the generic one: this will
most importantly make it easy to chain it with MTK_DISP_PWM (mtk-pwm-disp)
with a devicetree that looks like...

	pwmleds-disp {

		compatible = "pwm-leds";



		disp_led: disp-pwm {

			label = "backlight-pwm";

			pwms = <&pwm0 0 500000>;

			max-brightness = <1024>;

		};

	};



	backlight_lcd0: backlight {

		compatible = "led-backlight";

		leds = <&disp_led>, <&pmic_bl_led>;



		default-brightness-level = <300>;

	};

Regards,
Angelo