coreboot

Hello there

I'm trying to add support for the GPU MUX in my notebook but, i also seen it implemented in the Lenovo notebooks, and the GPIO also seems to be registered in my notebook, but it didn't take any use of it.

in the file "coreboot/src/mainboard/system76/tgl-h/variants/oryp8/gpio.c" is following to find
PAD_CFG_GPI(GPP_R16, NONE, DEEP), // BL_PWM_EN_EC
PAD_CFG_GPI(GPP_R17, NONE, DEEP), // PLVDD_RST_EC
PAD_CFG_GPI(GPP_R18, NONE, DEEP), // MUX_CTRL_BIOS
PAD_CFG_GPI(GPP_R19, NONE, DEEP), // PS8461_SW

soo the GPIOs for the MUX exist
and from the schematics i can see the MUX and how its connected

the Lenovo T430 got this in its devicetree.cb

chip drivers/lenovo/hybrid_graphics
device pnp ff.f on end # dummy
register "detect_gpio" = "21"
register "has_panel_hybrid_gpio" = "1"
register "panel_hybrid_gpio" = "52"
register "panel_integrated_lvl" = "1"
register "has_backlight_gpio" = "0"
register "has_dgpu_power_gpio" = "0"
register "has_thinker1" = "1"
end

but mine doesn't

can you someone of you maybe give me a little advise how to do it? i really don't wanna break anything.