MIPI-DSI display configuration on STM32mp157DAC custom board

[adnan_pasha]

Hi STM-Team,

We have the custom board based on the STM32MP157DAC board with KLD35176BVIB LCD display.
KLD35176BVIB is actually BOE3.49(VGA) + HX8394f  display.

We are using yocto build to configure the display panel changes.

I have attached my device tree configuration

1) I need to configure below pins.

Pin Name	Pin Number	Function	Implementation	Remarks
PA14	T2	TP_INT	Touch Panel interrupt	Reference design has only DSI_LCD_INT, combined for Display + TP
PD13	AA19	DSI_TE	Pin re-mapped	FUNCTION MOVED FROM PC6 TO PD13
PD15	J2	DSI_LCD_BL_CTRL	Pin re-mapped	Function moved from PA15
PH6	Y11	TP_RESET

I was not able to find how and where to map these pins for my display panel As I am not much familiar with ST pin-mapping I was not able to figure out these mappings.

2) I was also looking for the DSI defaul data and clk pins pinmapping in device tree but not able to find it for below pins.

DSI_D0P

DSI_D0N

DSI_D1P

DSI_D1N

DSI_CK_P

DSI_CK_N

DSI_RESET

DSI_LCD_INT

3) Additionally is there a display driver available for KLD35176BVIB if yes how to enable it an use it to bring up our display LCD if no which alternative driver can we use since i can't find BOE+hx8394f driver in driver/gpu/drm/panel/ files.

4) I wanted to also know what is the best way to make and track device tree changes for linux-kernel,u-boot, and TFA. Since directly making changes in /tmp folder doesn't seem to be the best solution.

Thanks.

[adnan_pasha · Accepted solution]

Hello,

1.  

• I have not configured the TE pin.

• The backlight pin is configured using PWM.

• The INT and RESET pins are configured and included in the touch panel configuration, which communicates over I2C.

  2.

As far as I understand, these pins do not require explicit configuration because they are by default assigned for DSI display communication.

3.

I was able to get the display working by using the HX8394F driver from the Linux Git repository and adding the display initialization sequence provided by the display vendor.
4.

I used the devtool modify command to set up a workspace and track changes using Git commits.

Thank you.