I have a Apalis TK1 on a Ixora Board. The Board gets power (jumper for always-on is set) from a external board, and this board has a LTC2954 chip to controller the power and the !Kill pin is connected to a gpio of the Apalis TK1 Board.
To keep the power on, this gpio needs to be pulled high no later then 512ms after power on, or the LTC2954 chip will switch off again.
I found the place to enable the gpio in the linux device tree, which works, but is ofcourse to late.
Then i tried to set it in u-boot in board/toradex/apalis-tk1/apalis-tk1.c at the end of arch_misc_init. But that is still too late for the LTC2954 controller…
Is there a place in u-boot where i could enable that gpio even earlier ? Or is there an inherent boot delay on the apalis TK1 or the Ixora Board ?
Can someone tell me how this feature is done on the Ixora board ? As far as i know, it also has such a LTC2954 Power controller…