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+---- Thread: LCD screen brightness/contrast (/showthread.php?tid=3271)
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RE: LCD screen brightness/contrast - psychedup - 02-17-2017
(02-17-2017, 04:15 AM)xalius Wrote: For the BSP (3.10.x) kernel the PWM output (PL10 according to the schematics) is afaik tied to the LCD driver and there should be some controls in the /sys/ filesystem.
If you look at the device tree:
Pin Config:
https://github.com/longsleep/build-pine64-image/blob/master/blobs/pine64.dts#L776
LCD Entry seems to have values too:
https://github.com/longsleep/build-pine64-image/blob/master/blobs/pine64.dts#L1965
PWM Driver entry, from the pinctrl phandle:
https://github.com/longsleep/build-pine64-image/blob/master/blobs/pine64.dts#L2071
from the compatible line it should be tied to a driver called "sunxi-pwm16"
Is this it?
Code:
chris@pinetoo /sys/bus/platform/devices/spwm0.10 $ cat uevent
OF_NAME=spwm0
OF_FULLNAME=/soc@01c00000/spwm0@0x01f03800
OF_TYPE=spwm0
OF_COMPATIBLE_0=allwinner,sunxi-pwm16
OF_COMPATIBLE_N=1
OF_ALIAS_0=spwm0
MODALIAS=of:Nspwm0Tspwm0Callwinner,sunxi-pwm16If so, how do we set the frequency/brightness?