Hung-Te Lin has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/32353 )
Change subject: board/kukui: Support ADC value for NC ......................................................................
Patch Set 6:
(1 comment)
https://review.coreboot.org/#/c/32353/6/src/mainboard/google/kukui/boardid.c File src/mainboard/google/kukui/boardid.c:
https://review.coreboot.org/#/c/32353/6/src/mainboard/google/kukui/boardid.c... PS6, Line 86: /* The last level is NC and may be larger than standard tolerance. */
I don't really understand how we get here when the pin is not connected. […]
MTK is still doing final confirm, but from what we understand for now is:
- The ADC may read from 0~1.5V+-50mV, so the max value from spec was set to 1.45V. - However, if not calibrated, the ADC may still see >1.45V. - So in our case, the NC caused ADC seeing higher voltage and returns something over standard tolerance.
For now both teams agreed to not restricting (or make it larger) tolerance for NC values.