Change in coreboot[master]: mb/google/hatch/variants/helios: Modify touchscreen power on sequence
Furquan Shaikh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/35907 )
Change subject: mb/google/hatch/variants/helios: Modify touchscreen power on sequence ......................................................................
Patch Set 5:
(1 comment)
https://review.coreboot.org/c/coreboot/+/35907/2/src/mainboard/google/hatch/... File src/mainboard/google/hatch/variants/helios/overridetree.cb:
https://review.coreboot.org/c/coreboot/+/35907/2/src/mainboard/google/hatch/... PS2, Line 113: register "generic.stop_gpio" = : "ACPI_GPIO_OUTPUT_ACTIVE_LOW(GPP_C4)" : register "generic.stop_delay_ms" = "15" : register "generic.stop_off_delay_ms" = "5"
Can you let me know why USI_REPORT_EN is translated to stop_gpio?
This is not clearly captured in the commit message, but my understanding is that GPP_C4 needs to be set low when entering suspend state since touchscreen is powered off and GPP_C4 being high results in power leakage via the touchscreen device. And so GPP_C4 is being used as stop_gpio so that it can be set to the right state as part of the power resource.
This motivation should be clearly captured in the commit message.
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Furquan Shaikh (Code Review)