Touchscreen hardware components

Applicable for

STM32MP13x lines, STM32MP15x lines, STM32MP25x lines

1. Article purpose[edit source]

The purpose of this article is to:

list the touchscreen hardware components that might be integrated in the different boards
link these components to the corresponding software framework(s)
point to the datasheet(s) of these components
explain, when necessary, how to configure these components

2. Software frameworks[edit source]

Domain	Peripheral	Software components			Comment
Domain	Peripheral	OP-TEE	Linux	STM32Cube	Comment
Visual and Inputs	Goodix GT9147		Inputs framework^[1]		Touchscreen input driver
Visual and Inputs	FocalTech FT6236		Inputs framework^[1]		Touchscreen input driver

3. Goodix GT9147[edit source]

The Goodix GT9147 is a single-layer multi-touch capacitive touch controller driver.

For details and the datasheet please contact the GT9147 driver provider.

3.1. Linux driver[edit source]

Bindings: Documentation/devicetree/bindings/input/touchscreen/goodix.yaml

Sources: drivers/input/touchscreen/goodix.c

Devicetree example: arch/arm/boot/dts/stm32mp157d-ev1.dts

...
&dsi {
	#address-cells = <1>;
	#size-cells = <0>;
	status = "okay";

	ports {
		#address-cells = <1>;
		#size-cells = <0>;

		port@0 {
			reg = <0>;
			dsi_in: endpoint {
				remote-endpoint = <&ltdc_ep0_out>;
			};
		};

		port@1 {
			reg = <1>;
			dsi_out: endpoint {
				remote-endpoint = <&dsi_panel_in>;
			};
		};
	};

	panel_dsi: panel-dsi@0 {
		compatible = "raydium,rm68200";
		reg = <0>;
		reset-gpios = <&gpiof 15 GPIO_ACTIVE_LOW>;
		backlight = <&panel_backlight>;
		power-supply = <&v3v3>;
		status = "okay";

		port {
			dsi_panel_in: endpoint {
				remote-endpoint = <&dsi_out>;
			};
		};
	};
};


&i2c2 {
...
	stmfx: stmfx@42 {
		compatible = "st,stmfx-0300";
		reg = <0x42>;
		interrupts = <8 IRQ_TYPE_EDGE_RISING>;
		interrupt-parent = <&gpioi>;
		vdd-supply = <&v3v3>;

		stmfx_pinctrl: pinctrl {
			compatible = "st,stmfx-0300-pinctrl";
			gpio-controller;
			#gpio-cells = <2>;
			interrupt-controller;
			#interrupt-cells = <2>;
			gpio-ranges = <&stmfx_pinctrl 0 0 24>;

			goodix_pins: goodix {
				pins = "gpio14";
				bias-pull-down;
			};

			joystick_pins: joystick-pins {
				pins = "gpio0", "gpio1", "gpio2", "gpio3", "gpio4";
				bias-pull-down;
			};
		};
	};

	gt9147: goodix-ts@5d {
		compatible = "goodix,gt9147";
		reg = <0x5d>;
		panel = <&panel_dsi>;
		pinctrl-0 = <&goodix_pins>;
		pinctrl-names = "default";
		AVDD28-supply = <&v3v3>;
		VDDIO-supply = <&v3v3>;
		status = "okay";

		interrupts = <14 IRQ_TYPE_EDGE_RISING>;
		interrupt-parent = <&stmfx_pinctrl>;
	};
};

4. FocalTech FT6236[edit source]

The FocalTech FT6236 is a self-capacitive touch panel controller driver.

For details and the datasheet please contact the FT6236 driver provider.

4.1. Linux driver[edit source]

Bindings: Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.yaml

Sources: drivers/input/touchscreen/edt-ft5x06.c

5. References[edit source]

↑ ^1.0 ^1.1 Linux Input Subsystem kernel API and userspace API

[kernel_input-1] 1.0 ^1.1 Linux Input Subsystem kernel API and userspace API

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