xref: /kernel/linux/linux-6.6/Documentation/ABI/testing/debugfs-cros-ec

What:		/sys/kernel/debug/<cros-ec-device>/console_log
Date:		September 2017
KernelVersion:	4.13
Description:
		If the EC supports the CONSOLE_READ command type, this file
		can be used to grab the EC logs. The kernel polls for the log
		and keeps its own buffer but userspace should grab this and
		write it out to some logs.

What:		/sys/kernel/debug/<cros-ec-device>/panicinfo
Date:		September 2017
KernelVersion:	4.13
Description:
		This file dumps the EC panic information from the previous
		reboot. This file will only exist if the PANIC_INFO command
		type is supported by the EC.

What:		/sys/kernel/debug/<cros-ec-device>/pdinfo
Date:		June 2018
KernelVersion:	4.17
Description:
		This file provides the port role, muxes and power debug
		information for all the USB PD/type-C ports available. If
		the are no ports available, this file will be just an empty
		file.

What:		/sys/kernel/debug/<cros-ec-device>/uptime
Date:		June 2019
KernelVersion:	5.3
Description:
		A u32 providing the time since EC booted in ms. This is
		is used for synchronizing the AP host time with the EC
		log. An error is returned if the command is not supported
		by the EC or there is a communication problem.

What:		/sys/kernel/debug/<cros-ec-device>/last_resume_result
Date:		June 2019
KernelVersion:	5.3
Description:
		Some ECs have a feature where they will track transitions to
		the (Intel) processor's SLP_S0 line, in order to detect cases
		where a system failed to go into S0ix. When the system resumes,
		an EC with this feature will return a summary of SLP_S0
		transitions that occurred. The last_resume_result file returns
		the most recent response from the AP's resume message to the EC.

		The bottom 31 bits contain a count of the number of SLP_S0
		transitions that occurred since the suspend message was
		received. Bit 31 is set if the EC attempted to wake the
		system due to a timeout when watching for SLP_S0 transitions.
		Callers can use this to detect a wake from the EC due to
		S0ix timeouts. The result will be zero if no suspend
		transitions have been attempted, or the EC does not support
		this feature.

		Output will be in the format: "0x%08x\n".

What:		/sys/kernel/debug/<cros-ec-device>/suspend_timeout_ms
Date:		August 2022
KernelVersion:	6.1
Description:
		Some ECs have a feature where they will track transitions of
		a hardware-controlled sleep line, such as Intel's SLP_S0 line,
		in order to detect cases where a system failed to go into deep
		sleep states. The suspend_timeout_ms file controls the amount of
		time in milliseconds the EC will wait before declaring a sleep
		timeout event and attempting to wake the system.

		Supply 0 to use the default value coded into EC firmware. Supply
		65535 (EC_HOST_SLEEP_TIMEOUT_INFINITE) to disable the EC sleep
		failure detection mechanism. Values in between 0 and 65535
		indicate the number of milliseconds the EC should wait after a
		sleep transition before declaring a timeout. This includes both
		the duration after a sleep command was received but before the
		hardware line changed, as well as the duration between when the
		hardware line changed and the kernel sent an EC resume command.

		Output will be in the format: "%u\n".