The STM32MP157 PWM does not work properly

[laizhihui2021]

Development environment: buildroot st/2024.02.3

Hardware: STM32MP157DAB1 (The schematic diagram is in "SCH-887T227012(A0)-20240815.pdf" in the attachment).

 

The LCD backlight pin of my board is connected to PF7, and I use the STM32CubeMX configuration as follows:

Then modify the generated device tree file to add backlight_pwm node as follows:

Then add pwm_backlight and panel_rgb, as shown below:

LTDC has also been modified as follows:

Screen parameters are written in buildroot/output/build/linux-custom/drivers/gpu/drm/panel/panel-simple.c

  After compiling and burning, print the following information:

[ 12.640841] platform pwm-backlight: deferred probe pending
[ 12.645020] platform 5a001000.display-controller: deferred probe pending
[ 12.651762] platform panel-rgb: deferred probe pending

 

 Please help to see, where is the problem with the configuration, which makes it impossible to load the above drivers?