Re: [PATCH 7/7] ARM: dts: r8a7742-iwg21d-q7: Add LCD support

[Laurent Pinchart]

Hi Prabhakar,

Thank you for the patch.

On Fri, Aug 07, 2020 at 06:49:54PM +0100, Lad Prabhakar wrote:
> The iwg21d comes with a 7" capacitive touch screen, therefore
> add support for it.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> Reviewed-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@xxxxxxxxxxxxxx>
> ---
>  arch/arm/boot/dts/r8a7742-iwg21d-q7.dts | 84 +++++++++++++++++++++++++
>  1 file changed, 84 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/r8a7742-iwg21d-q7.dts b/arch/arm/boot/dts/r8a7742-iwg21d-q7.dts
> index b3461a61a4bf..cf59fd61e422 100644
> --- a/arch/arm/boot/dts/r8a7742-iwg21d-q7.dts
> +++ b/arch/arm/boot/dts/r8a7742-iwg21d-q7.dts
> @@ -30,6 +30,7 @@
>  
>  /dts-v1/;
>  #include "r8a7742-iwg21m.dtsi"
> +#include <dt-bindings/pwm/pwm.h>
>  
>  / {
>  	model = "iWave Systems RainboW-G21D-Qseven board based on RZ/G1H";
> @@ -52,6 +53,50 @@
>  		clock-frequency = <26000000>;
>  	};
>  
> +	lcd_backlight: backlight {
> +		compatible = "pwm-backlight";
> +		pwms = <&tpu 2 5000000 0>;
> +		brightness-levels = <0 4 8 16 32 64 128 255>;
> +		pinctrl-0 = <&backlight_pins>;
> +		pinctrl-names = "default";
> +		default-brightness-level = <7>;
> +		enable-gpios = <&gpio3 11 GPIO_ACTIVE_HIGH>;

It's actually a power supply, not an enable GPIO, but it doesn't matter
much, I don't think there's a need to declare a regulator just for the
sake of it.

> +	};
> +
> +	lvds-receiver {
> +		compatible = "ti,ds90cf384a", "lvds-decoder";
> +		powerdown-gpios = <&gpio5 28 GPIO_ACTIVE_LOW>;

This should be handled as a shared power supply, as it's also needed for
the touch screen. Biju has sent patches for the iwg20d that fixes a
probe issue due to that problem, I think you can just copy the fix.

> +
> +		ports {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			port@0 {
> +				reg = <0>;
> +				lvds_receiver_in: endpoint {
> +					remote-endpoint = <&lvds0_out>;
> +				};
> +			};
> +			port@1 {
> +				reg = <1>;
> +				lvds_receiver_out: endpoint {
> +					remote-endpoint = <&panel_in>;
> +				};
> +			};
> +		};
> +	};
> +
> +	panel {
> +		compatible = "edt,etm0700g0dh6";
> +		backlight = <&lcd_backlight>;
> +
> +		port {
> +			panel_in: endpoint {
> +				remote-endpoint = <&lvds_receiver_out>;
> +			};
> +		};
> +	};
> +
>  	reg_1p5v: 1p5v {
>  		compatible = "regulator-fixed";
>  		regulator-name = "1P5V";
> @@ -129,12 +174,31 @@
>  		VDDIO-supply = <&reg_3p3v>;
>  		VDDD-supply = <&reg_1p5v>;
>  	};
> +
> +	touch: touchpanel@38 {
> +		compatible = "edt,edt-ft5406";
> +		reg = <0x38>;
> +		interrupt-parent = <&gpio0>;
> +		interrupts = <24 IRQ_TYPE_EDGE_FALLING>;

Should the reset GPIO also be wired ? It seems to be shared with the
audio codec though, which is annoying.

> +	};
>  };
>  
>  &cmt0 {
>  	status = "okay";
>  };
>  
> +&du {
> +	status = "okay";
> +};
> +
> +&gpio0 {
> +	touch-interrupt {
> +		gpio-hog;
> +		gpios = <24 GPIO_ACTIVE_LOW>;
> +		input;
> +	};

Is this needed, or does requesting the interrupt in the touch screen
driver configured the GPIO to an input automatically ?

> +};
> +
>  &hsusb {
>  	pinctrl-0 = <&usb0_pins>;
>  	pinctrl-names = "default";
> @@ -165,6 +229,11 @@
>  		function = "avb";
>  	};
>  
> +	backlight_pins: backlight {
> +		groups = "tpu0_to2";
> +		function = "tpu0";
> +	};
> +
>  	i2c2_pins: i2c2 {
>  		groups = "i2c2_b";
>  		function = "i2c2";
> @@ -208,6 +277,17 @@
>  	};
>  };
>  
> +&lvds0 {
> +	status = "okay";
> +	ports {
> +		port@1 {
> +			lvds0_out: endpoint {
> +				remote-endpoint = <&lvds_receiver_in>;
> +			};
> +		};
> +	};
> +};
> +
>  &rcar_sound {
>  	pinctrl-0 = <&sound_pins>;
>  	pinctrl-names = "default";
> @@ -261,6 +341,10 @@
>  	shared-pin;
>  };
>  
> +&tpu {
> +	status = "okay";
> +};
> +
>  &usbphy {
>  	status = "okay";
>  };

-- 
Regards,

Laurent Pinchart