The STMicroelectronics STM32MP15 provides a 24-bit RGB LCD-TFT display interface (LTDC). The SOC also provides a MIPI DSI host interface connected internally to the LTDC.

On the ConnectCore MP15:

  • The parallel LCD interface is available on the LGA pads, multiplexed with other functions.

  • The MIPI DSI interface is available on the LGA pads.

On the ConnectCore MP15 Development Kit:

  • The parallel LCD interface is available on the LCD connector.

  • The parallel LCD interface is routed to Rohm BU90T82 parallel-to-LVDS converter.

  • The MIPI DSI interface is available on an external connector.

  • The MIPI DSI interface is routed to the Lontium LT8912 MIPI-to-HDMI bridge.

Kernel configuration

You can manage the video support through the following kernel configuration options:

  • STM LCD controller driver (CONFIG_DRM_STM)

  • STM MIPI DSI DRM driver (CONFIG_DRM_STM_DSI)

These options are enabled as built-in on the default ConnectCore MP15 kernel configuration file.

Kernel driver

The driver for the video interface is located at:

File Description

drivers/gpu/drm/stm/drv.c

Video driver

drivers/gpu/drm/stm/dw_mipi_dsi-stm.c

DRM driver

Device tree bindings and customization

The LTDC controller and MIPI DSI interface are defined in the CPU device tree file.

Definition of the LTDC and MIPI DSI

ConnectCore MP15 Development Kit device tree
ltdc: display-controller@5a001000 {
	compatible = "st,stm32-ltdc";
	reg = <0x5a001000 0x400>;
	interrupts = <GIC_SPI 88 IRQ_TYPE_LEVEL_HIGH>,
		     <GIC_SPI 89 IRQ_TYPE_LEVEL_HIGH>;
	clocks = <&rcc LTDC_PX>;
	clock-names = "lcd";
	resets = <&rcc LTDC_R>;
	status = "disabled";

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

dsi: dsi@5a000000 {
	compatible = "st,stm32-dsi";
	reg = <0x5a000000 0x800>;
	phy-dsi-supply = <&reg18>;
	clocks = <&rcc DSI_K>, <&scmi_clk CK_SCMI_HSE>, <&rcc DSI_PX>;
	clock-names = "pclk", "ref", "px_clk";
	resets = <&rcc DSI_R>;
	reset-names = "apb";
	#address-cells = <1>;
	#size-cells = <0>;
	status = "disabled";

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

Display options

You need additional kernel and device tree configurations depending on the video display that you want to use. Find more information on the following sub-topics:

Use the video interface

For Wayland images, a Weston desktop launches after Linux starts.

Play a video

To play a video using Gstreamer:

# gst-launch-1.0 playbin uri=file:///run/media/sda1/big_buck_bunny_480p_h264.mp4
# gst-play-1.0 /run/media/sda1/big_buck_bunny_480p_h264.mp4
The default image does not include a video file.