On 10/5/18 4:43 PM, Zheng Bao wrote: > I transfer all the GPIO setting to my code.
What do you mean? did you have wrong GPIO settings before? > After this, the linux can turn the monitor on, but in BIOS stage, > monitor can not be turn on. > Is that the way it is? Can BIOS turn the display on? What exactly do you mean with BIOS? a VGA BIOS? it should work with the correct VBT. Same with a GOP driver. I'll add Matt in CC who has more experience with the proprietary graphics solutions. Personally, I would just implement the backlight control in coreboot and use libgfxinit as open-source solution. Register documentation can be found here [1][2] and soc/intel/broadwell/igd.c:311..344 as example how it worked on older platforms. Everything else you need are the correct settings for your board/panel which you can find by decoding the VBT or just dump the registers when Linux initialized it. Nico [1] BLC_PWM_(CTL|DATA) in https://01.org/sites/default/files/documentation/intel-gfx-prm-osrc-skl-vol02c-commandreference-registers-part1.pdf [2] PP_* and SBLC_PWM_CTL[12] in https://01.org/sites/default/files/documentation/intel-gfx-prm-osrc-skl-vol02c-commandreference-registers-part2.pdf -- coreboot mailing list: [email protected] https://mail.coreboot.org/mailman/listinfo/coreboot
