I'm trying to use gpio172 as a power latch on my custom board. U-boot
sets the pin to mode 4, and drives it high. This is fine.
When the kernel starts, it drops low for some reason, and releases my
power latch, and the board shuts off.
If I externally hold it high until my gpio_request_one(172,
GPIOF_OUT_INIT_HIGH, "POWERHOLD") command is run in the overo_init
function, then I am fine.
I've tried to trace down anything that could be altering gpio172, or
setting it to some other mode, but I haven't had any luck. I looked
in overo_init_early, omap3_map_io, etc.
I don't believe the kernel mux configuration is enabled, so I don't
think the kernel is changing my mux configuration.
I think this pin is shared with mmc2_dat5, and I went into hsmmc.c and
commented out the code which checks for the MMC_CAP_8_BIT_DATA flag
for mmc2. This didn't seem to change anything.
Does anyone have any other suggestions on where to look?