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Diffstat (limited to 'Documentation/ABI/testing/sysfs-power')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-power | 128 |
1 files changed, 113 insertions, 15 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 194ca446ac2..f4551816329 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -1,28 +1,40 @@ What: /sys/power/ Date: August 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> Description: The /sys/power directory will contain files that will provide a unified interface to the power management subsystem. What: /sys/power/state -Date: August 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> +Date: May 2014 +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> Description: - The /sys/power/state file controls the system power state. - Reading from this file returns what states are supported, - which is hard-coded to 'standby' (Power-On Suspend), 'mem' - (Suspend-to-RAM), and 'disk' (Suspend-to-Disk). + The /sys/power/state file controls system sleep states. + Reading from this file returns the available sleep state + labels, which may be "mem", "standby", "freeze" and "disk" + (hibernation). The meanings of the first three labels depend on + the relative_sleep_states command line argument as follows: + 1) relative_sleep_states = 1 + "mem", "standby", "freeze" represent non-hibernation sleep + states from the deepest ("mem", always present) to the + shallowest ("freeze"). "standby" and "freeze" may or may + not be present depending on the capabilities of the + platform. "freeze" can only be present if "standby" is + present. + 2) relative_sleep_states = 0 (default) + "mem" - "suspend-to-RAM", present if supported. + "standby" - "power-on suspend", present if supported. + "freeze" - "suspend-to-idle", always present. Writing to this file one of these strings causes the system to - transition into that state. Please see the file - Documentation/power/states.txt for a description of each of - these states. + transition into the corresponding state, if available. See + Documentation/power/states.txt for a description of what + "suspend-to-RAM", "power-on suspend" and "suspend-to-idle" mean. What: /sys/power/disk Date: September 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> Description: The /sys/power/disk file controls the operating mode of the suspend-to-disk mechanism. Reading from this file returns @@ -67,7 +79,7 @@ Description: What: /sys/power/image_size Date: August 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> Description: The /sys/power/image_size file controls the size of the image created by the suspend-to-disk mechanism. It can be written a @@ -84,7 +96,7 @@ Description: What: /sys/power/pm_trace Date: August 2006 -Contact: Rafael J. Wysocki <rjw@sisk.pl> +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> Description: The /sys/power/pm_trace file controls the code which saves the last PM event point in the RTC across reboots, so that you can @@ -133,7 +145,7 @@ Description: What: /sys/power/pm_async Date: January 2009 -Contact: Rafael J. Wysocki <rjw@sisk.pl> +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> Description: The /sys/power/pm_async file controls the switch allowing the user space to enable or disable asynchronous suspend and resume @@ -146,7 +158,7 @@ Description: What: /sys/power/wakeup_count Date: July 2010 -Contact: Rafael J. Wysocki <rjw@sisk.pl> +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> Description: The /sys/power/wakeup_count file allows user space to put the system into a sleep state while taking into account the @@ -158,3 +170,89 @@ Description: successful, will make the kernel abort a subsequent transition to a sleep state if any wakeup events are reported after the write has returned. + +What: /sys/power/reserved_size +Date: May 2011 +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> +Description: + The /sys/power/reserved_size file allows user space to control + the amount of memory reserved for allocations made by device + drivers during the "device freeze" stage of hibernation. It can + be written a string representing a non-negative integer that + will be used as the amount of memory to reserve for allocations + made by device drivers' "freeze" callbacks, in bytes. + + Reading from this file will display the current value, which is + set to 1 MB by default. + +What: /sys/power/autosleep +Date: April 2012 +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> +Description: + The /sys/power/autosleep file can be written one of the strings + returned by reads from /sys/power/state. If that happens, a + work item attempting to trigger a transition of the system to + the sleep state represented by that string is queued up. This + attempt will only succeed if there are no active wakeup sources + in the system at that time. After every execution, regardless + of whether or not the attempt to put the system to sleep has + succeeded, the work item requeues itself until user space + writes "off" to /sys/power/autosleep. + + Reading from this file causes the last string successfully + written to it to be returned. + +What: /sys/power/wake_lock +Date: February 2012 +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> +Description: + The /sys/power/wake_lock file allows user space to create + wakeup source objects and activate them on demand (if one of + those wakeup sources is active, reads from the + /sys/power/wakeup_count file block or return false). When a + string without white space is written to /sys/power/wake_lock, + it will be assumed to represent a wakeup source name. If there + is a wakeup source object with that name, it will be activated + (unless active already). Otherwise, a new wakeup source object + will be registered, assigned the given name and activated. + If a string written to /sys/power/wake_lock contains white + space, the part of the string preceding the white space will be + regarded as a wakeup source name and handled as descrived above. + The other part of the string will be regarded as a timeout (in + nanoseconds) such that the wakeup source will be automatically + deactivated after it has expired. The timeout, if present, is + set regardless of the current state of the wakeup source object + in question. + + Reads from this file return a string consisting of the names of + wakeup sources created with the help of it that are active at + the moment, separated with spaces. + + +What: /sys/power/wake_unlock +Date: February 2012 +Contact: Rafael J. Wysocki <rjw@rjwysocki.net> +Description: + The /sys/power/wake_unlock file allows user space to deactivate + wakeup sources created with the help of /sys/power/wake_lock. + When a string is written to /sys/power/wake_unlock, it will be + assumed to represent the name of a wakeup source to deactivate. + If a wakeup source object of that name exists and is active at + the moment, it will be deactivated. + + Reads from this file return a string consisting of the names of + wakeup sources created with the help of /sys/power/wake_lock + that are inactive at the moment, separated with spaces. + +What: /sys/power/pm_print_times +Date: May 2012 +Contact: Sameer Nanda <snanda@chromium.org> +Description: + The /sys/power/pm_print_times file allows user space to + control whether the time taken by devices to suspend and + resume is printed. These prints are useful for hunting down + devices that take too long to suspend or resume. + + Writing a "1" enables this printing while writing a "0" + disables it. The default value is "0". Reading from this file + will display the current value. |