Display bridges hardware components

Applicable for

STM32MP13x lines, STM32MP15x lines, Unknown MPU, Unknown MPU, STM32MP25x lines

---

1. Article purpose

The purpose of this article is to:

• List the display bridge hardware components that might be integrated in the different boards.
• Link these components to the corresponding software framework(s).
• Point to the appropriate component datasheets.
• Explain, when necessary, how to configure these components.

Information

Some of these hardware components are part of the accessories for STM32 boards like the B-LCDAD-HDMI1 for instance.

2. Software frameworks

Domain	Peripheral	Software components			Comment
		OP-TEE	Linux	STM32Cube
Visual	Analog Devices adv7533 & adv7535		DRM/KMS framework		MIPI® DSI to HDMI transmitter
Visual	Silab sil9022		DRM/KMS framework		Parallel RGB (DPI) to HDMI transmitter
Visual	Toshiba tc358762		DRM/KMS framework		MIPI® DSI to Parallel RGB (DPI)
Visual	Analog Devices adv7513		DRM/KMS framework		Parallel RGB (DPI) to HDMI transmitter

3. Analog Devices adv7533 & adv7535

The adv7533 and adv7535 (adv753x) DSI to HDMI transmitter support the HDMI^® Specification on a wide range of mobile products.

For details and the datasheet please contact the adv753x HDMI transmitter provider.

The adv753x transmitter does not support DSI burst mode. Check the pixel clock constraints in non-burst mode.

3.1. adv7533 related boards

Information

The adv7533 HDMI transmitter can be found on the adapter board B-LCDAD-HDMI1. It is compatible with the STM32MP157 evaluation boards and can be plugged in place of the display. But note that: Due to I2C address conflict, to use B-LCDAD-HDMI1 on STM32MP157 evaluation boards it is required to disconnect the camera module and remove the camera from the device tree. The display connector of STM32MP157 evaluation boards does not provide audio signals; the B-LCDAD-HDMI1 will only convert DSI video signals.

3.2. adv7535 related boards

Information

The adv7535 HDMI transmitter can be found on: STM32MP25 Discovery kit

3.3. Linux driver

Bindings: Documentation/devicetree/bindings/display/bridge/adi,adv7533.yaml (for both adv7533 & adv7535)

Sources: drivers/gpu/drm/bridge/adv7511/

Configuration:

• DRM_I2C_ADV7511
• DRM_I2C_ADV7511_AUDIO
• DRM_I2C_ADV7511_CEC

3.3.1. adv7533 device tree example

Devicetree example with the B-LCDAD-HDMI1 board connected to the STM32MP157 evaluation board: arch/arm/boot/dts/st/stm32mp157c-ev1.dts

/ {
	...
	hdmi-out {
		compatible = "hdmi-connector";
		type = "a";
	
		port {
			hdmi_con: endpoint {
					remote-endpoint = <&adv7533_out>;
				};
			};
	};
};

&dsi {
	#address-cells = <1>;
	#size-cells = <0>;
	status = "okay";
	ports {
		port@0 {
			reg = <0>;
			dsi_in: endpoint {
				remote-endpoint = <&ltdc_ep1_out>;
			};
		};

		port@1 {
			reg = <1>;
			dsi_out: endpoint {
				remote-endpoint = <&adv7533_in>;
			};
		};
	};
};

&i2c2 {
	adv7533: hdmi@3d {
		compatible = "adi,adv7533";
		reg = <0x3d>, <0x3c>, <0x3f>, <0x38>;
		reg-names = "main", "cec", "edid", "packet";
		status = "okay";
		adi,dsi-lanes = <2>;
		reset-gpios = <&gpiof 15 GPIO_ACTIVE_LOW>;

		ports {
			#address-cells = <1>;
			#size-cells = <0>;
			port@0 {
				reg = <0>;
				adv7533_in: endpoint {
					remote-endpoint = <&dsi_out>;
				};
			};

			port@1 {
				reg=<1>;
				adv7533_out: endpoint {
					remote-endpoint = <&hdmi_con>;
				};
			};
		};
	};
};

/* We disable the ov5640 node because it uses the same I2C address than HDMI-CEC */
&ov5640 {
	status = "disabled";
};

3.3.2. adv7535 device tree example

Devicetree example based on STM32MP25 Discovery kit: arch/arm64/boot/dts/st/stm32mp257f-dk.dts

/ {
...
	hdmi: connector {
		compatible = "hdmi-connector";
		label = "hdmi";
		type = "a";
		hdmi-pwr-supply = <&scmi_v5v_hdmi>;

		port {
			hdmi_connector_in: endpoint {
				remote-endpoint = <&adv7535_out>;
			};
		};
	};
...
};
...
&dsi {
	vdd-supply =  <&scmi_vddcore>;
	vdda18-supply = <&scmi_v1v8>;
	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_out1: endpoint {
				remote-endpoint = <&adv7535_in>;
			};
		};
	};
};
...

&i2c2 {
...
	adv7535: hdmi@3d {
		compatible = "adi,adv7535";
		reg = <0x3d>, <0x3c>, <0x3f>, <0x38>;
		reg-names = "main", "cec", "edid", "packet";
		status = "okay";
		adi,dsi-lanes = <4>;
		clocks = <&clk_ext_cec>;
		clock-names = "cec";
		interrupt-parent = <&gpiob>;
		interrupts = <4 IRQ_TYPE_EDGE_FALLING>;
		reset-gpios = <&gpiob 6 GPIO_ACTIVE_LOW>;
		avdd-supply = <&scmi_v1v8>;
		dvdd-supply = <&scmi_v1v8>;
		pvdd-supply = <&scmi_v1v8>;
		a2vdd-supply = <&scmi_v1v8>;
		v3p3-supply = <&scmi_v3v3>;
		v1p2-supply = <&scmi_v1v8>;

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

			port@0 {
				reg = <0>;
				adv7535_in: endpoint {
					remote-endpoint = <&dsi_out1>;
				};
			};

			port@1 {
				reg = <1>;
				adv7535_out: endpoint {
					remote-endpoint = <&hdmi_connector_in>;
				};
			};

			port@2 {
				reg = <2>;
				adv7535_tx_endpoint: endpoint {
					remote-endpoint = <&i2s2_endpoint>;
				};
			};
		};
	};
...
};
...
&ltdc {
	status = "okay";

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

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

		ltdc_ep1_out: endpoint@1 {
			reg = <1>;
			remote-endpoint = <&lvds_in>;
		};
	};
};

4. Silab sil9022

The SiI9022A HDMI transmitter supports the HDMI^® Specification on a wide range of mobile products.

For details and the datasheet please contact the SiI9022A HDMI transmitter provider.

Information

This HDMI transmitter can be found on some STM32MP1 Discovery kits.

4.1. Linux driver

Bindings: Documentation/devicetree/bindings/display/bridge/sil,sii9022.yaml

Sources: drivers/gpu/drm/bridge/sii902x.c

Configuration: DRM_SII902X

Devicetree example: arch/arm/boot/dts/st/stm32mp15xx-dkx.dtsi

&i2c1 {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&i2c1_pins_a>;
	pinctrl-1 = <&i2c1_sleep_pins_a>;
	i2c-scl-rising-time-ns = <100>;
	i2c-scl-falling-time-ns = <7>;
	status = "okay";
	/delete-property/dmas;
	/delete-property/dma-names;

	hdmi-transmitter@39 {
		compatible = "sil,sii9022";
		reg = <0x39>;
		iovcc-supply = <&v3v3_hdmi>;
		cvcc12-supply = <&v1v2_hdmi>;
		reset-gpios = <&gpioa 10 GPIO_ACTIVE_LOW>;
		interrupts = <1 IRQ_TYPE_EDGE_FALLING>;
		interrupt-parent = <&gpiog>;
		#sound-dai-cells = <0>;
		status = "okay";

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

			port@0 {
				reg = <0>;
				sii9022_in: endpoint {
					remote-endpoint = <&ltdc_ep0_out>;
				};
			};

			port@3 {
				reg = <3>;
				sii9022_tx_endpoint: endpoint {
					remote-endpoint = <&i2s2_endpoint>;
				};
			};
		};
	};
...
};

&ltdc {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&ltdc_pins_a>;
	pinctrl-1 = <&ltdc_sleep_pins_a>;
	status = "okay";

	port {
		ltdc_ep0_out: endpoint@0 {
			reg = <0>;
			remote-endpoint = <&sii9022_in>;
		};
	};
};

Devicetree pin control bindings example: arch/arm/boot/dts/st/stm32mp15-pinctrl.dtsi

&pinctrl {
...
	ltdc_pins_a: ltdc-0 {
		pins {
			pinmux = <STM32_PINMUX('G',  7, AF14)>, /* LCD_CLK */
				 <STM32_PINMUX('I', 10, AF14)>, /* LCD_HSYNC */
				 <STM32_PINMUX('I',  9, AF14)>, /* LCD_VSYNC */
				 <STM32_PINMUX('F', 10, AF14)>, /* LCD_DE */
				 <STM32_PINMUX('H',  2, AF14)>, /* LCD_R0 */
				 <STM32_PINMUX('H',  3, AF14)>, /* LCD_R1 */
				 <STM32_PINMUX('H',  8, AF14)>, /* LCD_R2 */
				 <STM32_PINMUX('H',  9, AF14)>, /* LCD_R3 */
				 <STM32_PINMUX('H', 10, AF14)>, /* LCD_R4 */
				 <STM32_PINMUX('C',  0, AF14)>, /* LCD_R5 */
				 <STM32_PINMUX('H', 12, AF14)>, /* LCD_R6 */
				 <STM32_PINMUX('E', 15, AF14)>, /* LCD_R7 */
				 <STM32_PINMUX('E',  5, AF14)>, /* LCD_G0 */
				 <STM32_PINMUX('E',  6, AF14)>, /* LCD_G1 */
				 <STM32_PINMUX('H', 13, AF14)>, /* LCD_G2 */
				 <STM32_PINMUX('H', 14, AF14)>, /* LCD_G3 */
				 <STM32_PINMUX('H', 15, AF14)>, /* LCD_G4 */
				 <STM32_PINMUX('I',  0, AF14)>, /* LCD_G5 */
				 <STM32_PINMUX('I',  1, AF14)>, /* LCD_G6 */
				 <STM32_PINMUX('I',  2, AF14)>, /* LCD_G7 */
				 <STM32_PINMUX('D',  9, AF14)>, /* LCD_B0 */
				 <STM32_PINMUX('G', 12, AF14)>, /* LCD_B1 */
				 <STM32_PINMUX('G', 10, AF14)>, /* LCD_B2 */
				 <STM32_PINMUX('D', 10, AF14)>, /* LCD_B3 */
				 <STM32_PINMUX('I',  4, AF14)>, /* LCD_B4 */
				 <STM32_PINMUX('A',  3, AF14)>, /* LCD_B5 */
				 <STM32_PINMUX('B',  8, AF14)>, /* LCD_B6 */
				 <STM32_PINMUX('D',  8, AF14)>; /* LCD_B7 */
			bias-disable;
			drive-push-pull;
			slew-rate = <1>;
		};
	};

	ltdc_sleep_pins_a: ltdc-sleep-0 {
		pins {
			pinmux = <STM32_PINMUX('G',  7, ANALOG)>, /* LCD_CLK */
				 <STM32_PINMUX('I', 10, ANALOG)>, /* LCD_HSYNC */
				 <STM32_PINMUX('I',  9, ANALOG)>, /* LCD_VSYNC */
				 <STM32_PINMUX('F', 10, ANALOG)>, /* LCD_DE */
				 <STM32_PINMUX('H',  2, ANALOG)>, /* LCD_R0 */
				 <STM32_PINMUX('H',  3, ANALOG)>, /* LCD_R1 */
				 <STM32_PINMUX('H',  8, ANALOG)>, /* LCD_R2 */
				 <STM32_PINMUX('H',  9, ANALOG)>, /* LCD_R3 */
				 <STM32_PINMUX('H', 10, ANALOG)>, /* LCD_R4 */
				 <STM32_PINMUX('C',  0, ANALOG)>, /* LCD_R5 */
				 <STM32_PINMUX('H', 12, ANALOG)>, /* LCD_R6 */
				 <STM32_PINMUX('E', 15, ANALOG)>, /* LCD_R7 */
				 <STM32_PINMUX('E',  5, ANALOG)>, /* LCD_G0 */
				 <STM32_PINMUX('E',  6, ANALOG)>, /* LCD_G1 */
				 <STM32_PINMUX('H', 13, ANALOG)>, /* LCD_G2 */
				 <STM32_PINMUX('H', 14, ANALOG)>, /* LCD_G3 */
				 <STM32_PINMUX('H', 15, ANALOG)>, /* LCD_G4 */
				 <STM32_PINMUX('I',  0, ANALOG)>, /* LCD_G5 */
				 <STM32_PINMUX('I',  1, ANALOG)>, /* LCD_G6 */
				 <STM32_PINMUX('I',  2, ANALOG)>, /* LCD_G7 */
				 <STM32_PINMUX('D',  9, ANALOG)>, /* LCD_B0 */
				 <STM32_PINMUX('G', 12, ANALOG)>, /* LCD_B1 */
				 <STM32_PINMUX('G', 10, ANALOG)>, /* LCD_B2 */
				 <STM32_PINMUX('D', 10, ANALOG)>, /* LCD_B3 */
				 <STM32_PINMUX('I',  4, ANALOG)>, /* LCD_B4 */
				 <STM32_PINMUX('A',  3, ANALOG)>, /* LCD_B5 */
				 <STM32_PINMUX('B',  8, ANALOG)>, /* LCD_B6 */
				 <STM32_PINMUX('D',  8, ANALOG)>; /* LCD_B7 */
		};
	};
...
};

5. Toshiba tc358762

The tc358762 is a DSI de-serializer to parallel DPI or DBI. Only DPI output is supported in current Linux driver.

For details and the datasheet please contact the tc358762 device provider.

5.1. Linux driver

Bindings: Documentation/devicetree/bindings/display/bridge/toshiba,tc358762.yaml

Sources: drivers/gpu/drm/bridge/tc358762.c

Configuration:

• DRM_TOSHIBA_TC358762

Devicetree example: check the complete example for the Raspberry Pi 7" Touch Display.

6. Analog Devices adv7513

The Analog Devices adv7513 Parallel RGB (DPI) to HDMI transmitter supports the HDMI^® Specification on a wide range of mobile products.

For details and the datasheet please contact the adv7513 HDMI transmitter provider.

Information

This HDMI transmitter can be found on some dh-electronics AVENGER 96Boards compliant consumer edition boards.

6.1. Linux driver

Bindings: Documentation/devicetree/bindings/display/bridge/adi,adv7511.yaml

Sources: drivers/gpu/drm/bridge/adv7511

Configuration:

• DRM_I2C_ADV7511
• DRM_I2C_ADV7511_AUDIO
• DRM_I2C_ADV7511_CEC

Devicetree example: arch/arm/boot/dts/st/stm32mp15xx-dhcor-avenger96.dtsi

/ {

	hdmi-out {
		compatible = "hdmi-connector";
		type = "a";

		port {
			hdmi_con: endpoint {
				remote-endpoint = <&adv7513_out>;
			};
		};
	};
...
	sound {
		compatible = "audio-graph-card";
		label = "STM32MP1-AV96-HDMI";
		dais = <&sai2a_port>;
		status = "okay";
	};
...
};

&i2c4 {
	hdmi-transmitter@3d {
		compatible = "adi,adv7513";
		reg = <0x3d>, <0x4d>, <0x2d>, <0x5d>;
		reg-names = "main", "edid", "cec", "packet";
		clocks = <&cec_clock>;
		clock-names = "cec";

		avdd-supply = <&v3v3>;
		dvdd-supply = <&v3v3>;
		pvdd-supply = <&v3v3>;
		dvdd-3v-supply = <&v3v3>;
		bgvdd-supply = <&v3v3>;

		interrupts = <9 IRQ_TYPE_EDGE_FALLING>;
		interrupt-parent = <&gpiog>;

		status = "okay";

		adi,input-depth = <8>;
		adi,input-colorspace = "rgb";
		adi,input-clock = "1x";

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

			port@0 {
				reg = <0>;
				adv7513_in: endpoint {
					remote-endpoint = <&ltdc_ep0_out>;
				};
			};

			port@1 {
				reg = <1>;
				adv7513_out: endpoint {
					remote-endpoint = <&hdmi_con>;
				};
			};

			port@2 {
				reg = <2>;
				adv7513_i2s0: endpoint {
					remote-endpoint = <&sai2a_endpoint>;
				};
			};
		};
	};
};

&ltdc {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&ltdc_pins_d>;
	pinctrl-1 = <&ltdc_sleep_pins_d>;
	status = "okay";

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

		ltdc_ep0_out: endpoint@0 {
			reg = <0>;
			remote-endpoint = <&adv7513_in>;
		};
	};
};

Devicetree pin control bindings example: arch/arm/boot/dts/st/stm32mp15-pinctrl.dtsi

&pinctrl {
...
	ltdc_pins_d: ltdc-3 {
		pins1 {
			pinmux = <STM32_PINMUX('G',  7, AF14)>; /* LCD_CLK */
			bias-disable;
			drive-push-pull;
			slew-rate = <3>;
		};
		pins2 {
			pinmux = <STM32_PINMUX('I', 10, AF14)>, /* LCD_HSYNC */
				 <STM32_PINMUX('I',  9, AF14)>, /* LCD_VSYNC */
				 <STM32_PINMUX('E', 13, AF14)>, /* LCD_DE */
				 <STM32_PINMUX('G', 13, AF14)>, /* LCD_R0 */
				 <STM32_PINMUX('H',  3, AF14)>, /* LCD_R1 */
				 <STM32_PINMUX('H',  8, AF14)>, /* LCD_R2 */
				 <STM32_PINMUX('H',  9, AF14)>, /* LCD_R3 */
				 <STM32_PINMUX('A',  5, AF14)>, /* LCD_R4 */
				 <STM32_PINMUX('H', 11, AF14)>, /* LCD_R5 */
				 <STM32_PINMUX('H', 12, AF14)>, /* LCD_R6 */
				 <STM32_PINMUX('E', 15, AF14)>, /* LCD_R7 */
				 <STM32_PINMUX('E',  5, AF14)>, /* LCD_G0 */
				 <STM32_PINMUX('B',  0, AF14)>, /* LCD_G1 */
				 <STM32_PINMUX('H', 13, AF14)>, /* LCD_G2 */
				 <STM32_PINMUX('E', 11, AF14)>, /* LCD_G3 */
				 <STM32_PINMUX('H', 15, AF14)>, /* LCD_G4 */
				 <STM32_PINMUX('H',  4,  AF9)>, /* LCD_G5 */
				 <STM32_PINMUX('I', 11,  AF9)>, /* LCD_G6 */
				 <STM32_PINMUX('G',  8, AF14)>, /* LCD_G7 */
				 <STM32_PINMUX('D',  9, AF14)>, /* LCD_B0 */
				 <STM32_PINMUX('G', 12, AF14)>, /* LCD_B1 */
				 <STM32_PINMUX('G', 10, AF14)>, /* LCD_B2 */
				 <STM32_PINMUX('D', 10, AF14)>, /* LCD_B3 */
				 <STM32_PINMUX('E', 12, AF14)>, /* LCD_B4 */
				 <STM32_PINMUX('A',  3, AF14)>, /* LCD_B5 */
				 <STM32_PINMUX('B',  8, AF14)>, /* LCD_B6 */
				 <STM32_PINMUX('I',  7, AF14)>; /* LCD_B7 */
			bias-disable;
			drive-push-pull;
			slew-rate = <2>;
		};
	};

	ltdc_sleep_pins_d: ltdc-sleep-3 {
		pins {
			pinmux = <STM32_PINMUX('G',  7, ANALOG)>, /* LCD_CLK */
				 <STM32_PINMUX('I', 10, ANALOG)>, /* LCD_HSYNC */
				 <STM32_PINMUX('I',  9, ANALOG)>, /* LCD_VSYNC */
				 <STM32_PINMUX('E', 13, ANALOG)>, /* LCD_DE */
				 <STM32_PINMUX('G', 13, ANALOG)>, /* LCD_R0 */
				 <STM32_PINMUX('H',  3, ANALOG)>, /* LCD_R1 */
				 <STM32_PINMUX('H',  8, ANALOG)>, /* LCD_R2 */
				 <STM32_PINMUX('H',  9, ANALOG)>, /* LCD_R3 */
				 <STM32_PINMUX('A',  5, ANALOG)>, /* LCD_R4 */
				 <STM32_PINMUX('H', 11, ANALOG)>, /* LCD_R5 */
				 <STM32_PINMUX('H', 12, ANALOG)>, /* LCD_R6 */
				 <STM32_PINMUX('E', 15, ANALOG)>, /* LCD_R7 */
				 <STM32_PINMUX('E',  5, ANALOG)>, /* LCD_G0 */
				 <STM32_PINMUX('B',  0, ANALOG)>, /* LCD_G1 */
				 <STM32_PINMUX('H', 13, ANALOG)>, /* LCD_G2 */
				 <STM32_PINMUX('E', 11, ANALOG)>, /* LCD_G3 */
				 <STM32_PINMUX('H', 15, ANALOG)>, /* LCD_G4 */
				 <STM32_PINMUX('H',  4, ANALOG)>, /* LCD_G5 */
				 <STM32_PINMUX('I', 11, ANALOG)>, /* LCD_G6 */
				 <STM32_PINMUX('G',  8, ANALOG)>, /* LCD_G7 */
				 <STM32_PINMUX('D',  9, ANALOG)>, /* LCD_B0 */
				 <STM32_PINMUX('G', 12, ANALOG)>, /* LCD_B1 */
				 <STM32_PINMUX('G', 10, ANALOG)>, /* LCD_B2 */
				 <STM32_PINMUX('D', 10, ANALOG)>, /* LCD_B3 */
				 <STM32_PINMUX('E', 12, ANALOG)>, /* LCD_B4 */
				 <STM32_PINMUX('A',  3, ANALOG)>, /* LCD_B5 */
				 <STM32_PINMUX('B',  8, ANALOG)>, /* LCD_B6 */
				 <STM32_PINMUX('I',  7, ANALOG)>; /* LCD_B7 */
		};
	};

...
};

7. References

Microprocessor unit

Open portable trusted execution environment

Linux^® is a registered trademark of Linus Torvalds.

Mobile Industry Processor Interface, open membership organization that includes leading companies in the mobile industry that share the objective of defining and promoting open specifications for interfaces inside mobile terminals, see MIPI^® Alliance standard web site https://www.mipi.org

Display serial interface (MIPI^® Alliance standard)

High-definition multimedia interface (HDMI standard)

Display pixel interface (MIPI^® Alliance standard)

Inter-integrated circuit (Bi-directional 2-wire bus standard for efficient inter-IC control.)

Direct rendering manager (kernel module that gives direct hardware access to DRI clients, find more information on official DRI web site http://dri.freedesktop.org/wiki/DRM)

Consumer electronics control (HDMI standard)

General-purpose input/output (A realization of open ended transmission between devices on an embedded level. These pins available on a processor can be programmed to be used to either accept input or provide output to external devices depending on user desires and applications requirements.)

Display bus interface (MIPI^® Alliance standard)