The driver need to be copied to the folder
system/lib/hw/
and after reboot it should do his job.The driver loads the kernel modules for pwm automatically, so pwm-meson.ko and pwm-ctrl.ko must be present, what they should normally.
If you use this, you won't be able to use the pwm for other than backlight, also not the pin 33.
The driver: To copy to Odroid C1:
adb push lights.odroidc.so /system/lib/hw/
[edit]
To support also screen like VU8 this version read bootarg
backlight_pwm=yes|no|invert
.Need to add in boot.ini as follow:
Code: Select all
# Enable backlight_pwm
# backlight_pwm=yes, no, invert
backlight_pwm=yes
# Booting
setenv bootargs "root=/dev/mmcblk0p2 rw console=ttyS0,115200n8 no_console_suspend vdaccfg=${vdac_config} logo=osd1,loaded,${fb_addr},${outputmode},full hdmimode=${hdmimode} cvbsmode=${cvbsmode} hdmitx=${cecconfig} vout=${vout_mode} disablehpd=${disablehpd} ${disableuhs} androidboot.serialno=${fbt_id#} ir_remote=${ir_remote} usbcore.autosuspend=-1 ${selinuxopt} suspend_hdmiphy=${suspend_hdmiphy}} backlight_pwm=${backlight_pwm}"
To control the backlight of the VU7+ there is to do a little tinkering. At the pin 4 of the PT4103 backlight driver must be soldered a resistor. I used a 330 Ohms type. But it should also be possible without resistor. Other than in this picture the EN pin on the VU7+ has pull up resistor 10k to be enabled always. I measured the current when the EN pin is connected to GND, it is about 0.5mA which comes from the pull up resistor: 5V divided by 10k. But I put a resistor, call it fear resistor
