Kernel Splash Screen, set backlight on

Technical Support
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1

Hi,

I want to show a splash screen image when linux kernel boots. I have read:

Showing a splash screen from u-boot already works, but our display obviously has “inverted” backlight logic. That’s why I needed to change the function enable_rgb() in apalis_imx6.c (u-boot):

#define RGB_BACKLIGHTPWM_GP IMX_GPIO_NR(2, 10)

 static void enable_rgb(struct display_info_t const *dev)
- gpio_direction_output(RGB_BACKLIGHTPWM_GP, 0);
+ gpio_direction_output(RGB_BACKLIGHTPWM_GP, 1);

The problem is, that right when the Kernel starts, obviously the pin gets reset.
The backlight kernel driver built in the kernel (drivers/video/backlight/pwm_bl.c) is loaded at the very end of the booting process. So what 's the preferred way to set the pin more early in the kernel booting process?

Shall I just use the same command as in u-boot in kernel? Where to put it?

best regards,
Matthias

2

Hi @mkock

Could you provide the Software version of your module? Which carrier board are you using?

Could you provide a dmesg log in a file? Did you make any changes to the kernel and device tree?
If yes, could you share them?

Best regards, Jaski