Guidance Required for MIPI DSI Display Initialization on STM32H747

[siddum]

Dear ST Community,

We are working on a custom board using the STM32H747XG controller with a MIPI DSI display interface.

Our display panel is RK055MHD091A0-CTG, with a resolution of 720 × 1280. The display uses the HX8394-F TFT driver IC, and we are using the 2-lane MIPI DSI interface:

• DSI Data Lane 0

• DSI Data Lane 1

• DSI Clock Lane

We have configured the STM32H747 DSI Host in Video Mode and are using LTDC with an SDRAM framebuffer.

The HX8394-F supports DBI Type C option 1, 3-wire serial bus to access command set under DSI I/F. The 3-wire serial bus is use: chip select line (CSX), serial input data (SDI),serial output data (SDO) and serial transfer clock line (SCL).

According to the HX8394-F display driver requirements, the panel requires an initialization sequence with several commands for configuring parameters such as power, MIPI settings, gamma, GIP, etc., before starting the display.

We would like guidance on the correct way to send these HX8394-F initialization commands from the STM32H747 through the MIPI DSI interface.

Specifically, we would like to confirm:

1. Can the HX8394-F initialization commands be sent through the MIPI DSI interface before starting Video Mode?

2. Should we use HAL_DSI_ShortWrite() and HAL_DSI_LongWrite() to send the initialization commands?

3. Which DSI packet types should be used for HX8394-F manufacturer-specific commands: Generic Write or DCS Write?

Thank you for your support.

Best regards,
siddu m.