1What:		/sys/devices/.../power/
2Date:		January 2009
3Contact:	Rafael J. Wysocki <rjw@sisk.pl>
4Description:
5		The /sys/devices/.../power directory contains attributes
6		allowing the user space to check and modify some power
7		management related properties of given device.
8
9What:		/sys/devices/.../power/wakeup
10Date:		January 2009
11Contact:	Rafael J. Wysocki <rjw@sisk.pl>
12Description:
13		The /sys/devices/.../power/wakeup attribute allows the user
14		space to check if the device is enabled to wake up the system
15		from sleep states, such as the memory sleep state (suspend to
16		RAM) and hibernation (suspend to disk), and to enable or disable
17		it to do that as desired.
18
19		Some devices support "wakeup" events, which are hardware signals
20		used to activate the system from a sleep state.  Such devices
21		have one of the following two values for the sysfs power/wakeup
22		file:
23
24		+ "enabled\n" to issue the events;
25		+ "disabled\n" not to do so;
26
27		In that cases the user space can change the setting represented
28		by the contents of this file by writing either "enabled", or
29		"disabled" to it.
30
31		For the devices that are not capable of generating system wakeup
32		events this file contains "\n".  In that cases the user space
33		cannot modify the contents of this file and the device cannot be
34		enabled to wake up the system.
35
36What:		/sys/devices/.../power/control
37Date:		January 2009
38Contact:	Rafael J. Wysocki <rjw@sisk.pl>
39Description:
40		The /sys/devices/.../power/control attribute allows the user
41		space to control the run-time power management of the device.
42
43		All devices have one of the following two values for the
44		power/control file:
45
46		+ "auto\n" to allow the device to be power managed at run time;
47		+ "on\n" to prevent the device from being power managed;
48
49		The default for all devices is "auto", which means that they may
50		be subject to automatic power management, depending on their
51		drivers.  Changing this attribute to "on" prevents the driver
52		from power managing the device at run time.  Doing that while
53		the device is suspended causes it to be woken up.
54