[M] Change in coreboot[main]: soc/intel/cse: Implement APIs to access PSR backup status in CMOS

[Krishna P Bhat D (Code Review)]

Attention is currently required from: Jérémy Compostella, Rizwan Qureshi, Subrata Banik, sridhar siricilla.

Krishna P Bhat D has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/77069?usp=email )

Change subject: soc/intel/cse: Implement APIs to access PSR backup status in CMOS
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Patch Set 7:

(6 comments)

File src/soc/intel/common/block/cse/cse_lite_cmos.h:

https://review.coreboot.org/c/coreboot/+/77069/comment/f612880d_b318bab8 :
PS6, Line 14: psr_backup_status
> nit: if this is variable name then please use ``` ` ````

Acknowledged

https://review.coreboot.org/c/coreboot/+/77069/comment/09b1f2f7_b21ceac1 :
PS6, Line 19: status
> what is the definition of `current status` is there any enum to refer ?

Done

https://review.coreboot.org/c/coreboot/+/77069/comment/989a6204_aa694d85 :
PS6, Line 19: 0
> why not `-1` as error instead 0?

Acknowledged

File src/soc/intel/common/block/cse/cse_lite_cmos.c:

https://review.coreboot.org/c/coreboot/+/77069/comment/638cc1e2_008852a8 :
PS5, Line 115: get_psr_backup_status
> as mentioned, specify the expected values ?

Done

https://review.coreboot.org/c/coreboot/+/77069/comment/ae700542_7535af49 :
PS5, Line 115: uint8_t
> > There is no need to return -1 as error here, as the check would be for PSR_BACKUP_DONE or not in t […]

Acknowledged

File src/soc/intel/common/block/include/intelblocks/cse.h:

https://review.coreboot.org/c/coreboot/+/77069/comment/c01af006_6fd67abf :
PS5, Line 172: 0x22
> > No specific meaning, this value is chosen by us. […]

We would like to maintain only two states, PSR_BACKUP_DONE and PSR_BACKUP_PENDING in CMOS.