https://github.com/raspberrypi/linux/bl ... ay.dts#L65
ugh.. hardcoded to ACTIVE_HIGH
weird how I got the one screen that is ACTIVE_LOW?
I suppose I might have to recompile that dts (or write my lame userland service) though that doesn't solve PWM
I was wondering if there's a way to use pwm-gpio (kernel software pwm) to make it work? not that familiar with making overlays and such; was partly hoping I could configure GPIO22 as pwm-gpio and maybe it would work (though brightness would still be inverted I suppose)
any direction appreciated as always
If your display backlight is active low then it's your displays problem. Write a custom overlay and you're good.
The Pi Zero has two HW PWM, they are available from GPIO12/18=PWM0 and GPIO13/19=PWM1.
If you really think you'll need PWM backlight for such small display you can make use of SW-PWM.
https://github.com/raspberrypi/linux/bl ... 4183-L4186
you will have to change the mipi-dbi-spi overlay for that. Would suggest you get your display running first (with on/off for backlight) and then look into writing a custom overlay.
Sorry, the rest ist up to you!
Statistics: Posted by aBUGSworstnightmare — Sun Jan 11, 2026 6:39 pm