[M] Change in coreboot[master]: mb/google/rex: Configure ISH GPIO's based on FW_CONFIG

[Subrata Banik (Code Review)]

Attention is currently required from: Bernardo Perez Priego, Jamie Ryu, Jay Patel, Kapil Porwal, Li1 Feng, Tarun Tuli, Wonkyu Kim.

Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/75525?usp=email )

Change subject: mb/google/rex: Configure ISH GPIO's based on FW_CONFIG
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Patch Set 8:

(2 comments)

File src/mainboard/google/rex/variants/rex0/fw_config.c:

https://review.coreboot.org/c/coreboot/+/75525/comment/7ca2e8e3_3751fab2 :
PS8, Line 104: 1
> I assumed that this CBI should be the mechanism to determine if Proto1 or Proto2.
> If this should not be the way, could you please suggest any other method to differentiate them?

I don't understand the Proto 1 vs Proto 2 dependency.

Are you expecting to see different PIN between Proto 1 vs Proto 2? If yes, then the latest HW is what we should be supporting (which is Proto 1 until we have Proto 2)

https://review.coreboot.org/c/coreboot/+/75525/comment/b9657c8b_6e3f1728 :
PS8, Line 111: printk(BIOS_ERR, "Unknown Board Version for ISH.\n");
> I assumed that it would not configure any GPIO pin if board was not determined.

what is the downside, will system be able to enter S0ix ?
will we observe any abnormalities ? if yes, then better to die