Change in coreboot[master]: qualcomm/sc7280: gpio: Support eGPIO scheme

[Julius Werner (Code Review)]

Attention is currently required from: Shelley Chen, Ravi kumar, Taniya Das, Paul Menzel, mturney mturney.
Julius Werner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/55078 )

Change subject: qualcomm/sc7280: gpio: Support eGPIO scheme
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Patch Set 12:

(1 comment)

File src/soc/qualcomm/sc7280/sc7280_egpio.c:

https://review.coreboot.org/c/coreboot/+/55078/comment/764fdde7_26c2e693 
PS3, Line 56: 		setbits32(&regs->cfg, BIT(EGPIO_CFG_EN));
> > > > […]

Sorry, I still don't understand. The code you wrote here runs on the CPU, right? Just as kernel code would. So why can't the kernel run this code during GPIO/pinmux probe instead? Are the EGPIO_CFG registers you're writing here protected in some way so that they would become inaccessible later in the boot flow, or at a lower exception level?