kernel/power/Kconfig - arm/linux - Git at Google

 config SUSPEND
 	bool "Suspend to RAM and standby"
 	depends on ARCH_SUSPEND_POSSIBLE
 	default y
 	---help---
 	  Allow the system to enter sleep states in which main memory is
 	  powered and thus its contents are preserved, such as the
 	  suspend-to-RAM state (e.g. the ACPI S3 state).

 config SUSPEND_FREEZER
 	bool "Enable freezer for suspend to RAM/standby" \
 		if ARCH_WANTS_FREEZER_CONTROL || BROKEN
 	depends on SUSPEND
 	default y
 	help
 	  This allows you to turn off the freezer for suspend. If this is
 	  done, no tasks are frozen for suspend to RAM/standby.

 	  Turning OFF this setting is NOT recommended! If in doubt, say Y.

 config HIBERNATE_CALLBACKS
 	bool

 config HIBERNATION
 	bool "Hibernation (aka 'suspend to disk')"
 	depends on SWAP && ARCH_HIBERNATION_POSSIBLE
 	select HIBERNATE_CALLBACKS
 	select LZO_COMPRESS
 	select LZO_DECOMPRESS
 	---help---
 	  Enable the suspend to disk (STD) functionality, which is usually
 	  called "hibernation" in user interfaces.  STD checkpoints the
 	  system and powers it off; and restores that checkpoint on reboot.

 	  You can suspend your machine with 'echo disk > /sys/power/state'
 	  after placing resume=/dev/swappartition on the kernel command line
 	  in your bootloader's configuration file.

 	  Alternatively, you can use the additional userland tools available
 	  from <http://suspend.sf.net>.

 	  In principle it does not require ACPI or APM, although for example
 	  ACPI will be used for the final steps when it is available.  One
 	  of the reasons to use software suspend is that the firmware hooks
 	  for suspend states like suspend-to-RAM (STR) often don't work very
 	  well with Linux.

 	  It creates an image which is saved in your active swap. Upon the next
 	  boot, pass the 'resume=/dev/swappartition' argument to the kernel to
 	  have it detect the saved image, restore memory state from it, and
 	  continue to run as before. If you do not want the previous state to
 	  be reloaded, then use the 'noresume' kernel command line argument.
 	  Note, however, that fsck will be run on your filesystems and you will
 	  need to run mkswap against the swap partition used for the suspend.

 	  It also works with swap files to a limited extent (for details see
 	  <file:Documentation/power/swsusp-and-swap-files.txt>).

 	  Right now you may boot without resuming and resume later but in the
 	  meantime you cannot use the swap partition(s)/file(s) involved in
 	  suspending.  Also in this case you must not use the filesystems
 	  that were mounted before the suspend.  In particular, you MUST NOT
 	  MOUNT any journaled filesystems mounted before the suspend or they
 	  will get corrupted in a nasty way.

 	  For more information take a look at <file:Documentation/power/swsusp.txt>.

 config PM_STD_PARTITION
 	string "Default resume partition"
 	depends on HIBERNATION
 	default ""
 	---help---
 	  The default resume partition is the partition that the suspend-
 	  to-disk implementation will look for a suspended disk image.

 	  The partition specified here will be different for almost every user.
 	  It should be a valid swap partition (at least for now) that is turned
 	  on before suspending.

 	  The partition specified can be overridden by specifying:

 		resume=/dev/<other device>

 	  which will set the resume partition to the device specified.

 	  Note there is currently not a way to specify which device to save the
 	  suspended image to. It will simply pick the first available swap
 	  device.

 config PM_SLEEP
 	def_bool y
 	depends on SUSPEND || HIBERNATE_CALLBACKS

 config PM_SLEEP_SMP
 	def_bool y
 	depends on SMP
 	depends on ARCH_SUSPEND_POSSIBLE || ARCH_HIBERNATION_POSSIBLE
 	depends on PM_SLEEP
 	select HOTPLUG
 	select HOTPLUG_CPU

 config PM_RUNTIME
 	bool "Run-time PM core functionality"
 	depends on !IA64_HP_SIM
 	---help---
 	  Enable functionality allowing I/O devices to be put into energy-saving
 	  (low power) states at run time (or autosuspended) after a specified
 	  period of inactivity and woken up in response to a hardware-generated
 	  wake-up event or a driver's request.

 	  Hardware support is generally required for this functionality to work
 	  and the bus type drivers of the buses the devices are on are
 	  responsible for the actual handling of the autosuspend requests and
 	  wake-up events.

 config PM
 	def_bool y
 	depends on PM_SLEEP || PM_RUNTIME

 config PM_DEBUG
 	bool "Power Management Debug Support"
 	depends on PM
 	---help---
 	This option enables various debugging support in the Power Management
 	code. This is helpful when debugging and reporting PM bugs, like
 	suspend support.

 config PM_ADVANCED_DEBUG
 	bool "Extra PM attributes in sysfs for low-level debugging/testing"
 	depends on PM_DEBUG
 	---help---
 	Add extra sysfs attributes allowing one to access some Power Management
 	fields of device objects from user space.  If you are not a kernel
 	developer interested in debugging/testing Power Management, say "no".

 config PM_TEST_SUSPEND
 	bool "Test suspend/resume and wakealarm during bootup"
 	depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
 	---help---
 	This option will let you suspend your machine during bootup, and
 	make it wake up a few seconds later using an RTC wakeup alarm.
 	Enable this with a kernel parameter like "test_suspend=mem".

 	You probably want to have your system's RTC driver statically
 	linked, ensuring that it's available when this test runs.

 config CAN_PM_TRACE
 	def_bool y
 	depends on PM_DEBUG && PM_SLEEP

 config PM_TRACE
 	bool
 	help
 	  This enables code to save the last PM event point across
 	  reboot. The architecture needs to support this, x86 for
 	  example does by saving things in the RTC, see below.

 	  The architecture specific code must provide the extern
 	  functions from <linux/resume-trace.h> as well as the
 	  <asm/resume-trace.h> header with a TRACE_RESUME() macro.

 	  The way the information is presented is architecture-
 	  dependent, x86 will print the information during a
 	  late_initcall.

 config PM_TRACE_RTC
 	bool "Suspend/resume event tracing"
 	depends on CAN_PM_TRACE
 	depends on X86
 	select PM_TRACE
 	---help---
 	This enables some cheesy code to save the last PM event point in the
 	RTC across reboots, so that you can debug a machine that just hangs
 	during suspend (or more commonly, during resume).

 	To use this debugging feature you should attempt to suspend the
 	machine, reboot it and then run

 		dmesg -s 1000000 | grep 'hash matches'

 	CAUTION: this option will cause your machine's real-time clock to be
 	set to an invalid time after a resume.

 config APM_EMULATION
 	tristate "Advanced Power Management Emulation"
 	depends on PM && SYS_SUPPORTS_APM_EMULATION
 	help
 	  APM is a BIOS specification for saving power using several different
 	  techniques. This is mostly useful for battery powered laptops with
 	  APM compliant BIOSes. If you say Y here, the system time will be
 	  reset after a RESUME operation, the /proc/apm device will provide
 	  battery status information, and user-space programs will receive
 	  notification of APM "events" (e.g. battery status change).

 	  In order to use APM, you will need supporting software. For location
 	  and more information, read <file:Documentation/power/pm.txt> and the
 	  Battery Powered Linux mini-HOWTO, available from
 	  <http://www.tldp.org/docs.html#howto>.

 	  This driver does not spin down disk drives (see the hdparm(8)
 	  manpage ("man 8 hdparm") for that), and it doesn't turn off
 	  VESA-compliant "green" monitors.

 	  Generally, if you don't have a battery in your machine, there isn't
 	  much point in using this driver and you should say N. If you get
 	  random kernel OOPSes or reboots that don't seem to be related to
 	  anything, try disabling/enabling this option (or disabling/enabling
 	  APM in your BIOS).

 config ARCH_HAS_OPP
 	bool

 config PM_OPP
 	bool "Operating Performance Point (OPP) Layer library"
 	depends on ARCH_HAS_OPP
 	---help---
 	  SOCs have a standard set of tuples consisting of frequency and
 	  voltage pairs that the device will support per voltage domain. This
 	  is called Operating Performance Point or OPP. The actual definitions
 	  of OPP varies over silicon within the same family of devices.

 	  OPP layer organizes the data internally using device pointers
 	  representing individual voltage domains and provides SOC
 	  implementations a ready to use framework to manage OPPs.
 	  For more information, read <file:Documentation/power/opp.txt>

 config PM_CLK
 	def_bool y
 	depends on PM && HAVE_CLK

 config PM_GENERIC_DOMAINS
 	bool
 	depends on PM
	config SUSPEND
	bool "Suspend to RAM and standby"
	depends on ARCH_SUSPEND_POSSIBLE
	default y
	---help---
	Allow the system to enter sleep states in which main memory is
	powered and thus its contents are preserved, such as the
	suspend-to-RAM state (e.g. the ACPI S3 state).

	config SUSPEND_FREEZER
	bool "Enable freezer for suspend to RAM/standby" \
	if ARCH_WANTS_FREEZER_CONTROL \|\| BROKEN
	depends on SUSPEND
	default y
	help
	This allows you to turn off the freezer for suspend. If this is
	done, no tasks are frozen for suspend to RAM/standby.

	Turning OFF this setting is NOT recommended! If in doubt, say Y.

	config HIBERNATE_CALLBACKS
	bool

	config HIBERNATION
	bool "Hibernation (aka 'suspend to disk')"
	depends on SWAP && ARCH_HIBERNATION_POSSIBLE
	select HIBERNATE_CALLBACKS
	select LZO_COMPRESS
	select LZO_DECOMPRESS
	---help---
	Enable the suspend to disk (STD) functionality, which is usually
	called "hibernation" in user interfaces. STD checkpoints the
	system and powers it off; and restores that checkpoint on reboot.

	You can suspend your machine with 'echo disk > /sys/power/state'
	after placing resume=/dev/swappartition on the kernel command line
	in your bootloader's configuration file.

	Alternatively, you can use the additional userland tools available
	from <http://suspend.sf.net>.

	In principle it does not require ACPI or APM, although for example
	ACPI will be used for the final steps when it is available. One
	of the reasons to use software suspend is that the firmware hooks
	for suspend states like suspend-to-RAM (STR) often don't work very
	well with Linux.

	It creates an image which is saved in your active swap. Upon the next
	boot, pass the 'resume=/dev/swappartition' argument to the kernel to
	have it detect the saved image, restore memory state from it, and
	continue to run as before. If you do not want the previous state to
	be reloaded, then use the 'noresume' kernel command line argument.
	Note, however, that fsck will be run on your filesystems and you will
	need to run mkswap against the swap partition used for the suspend.

	It also works with swap files to a limited extent (for details see
	<file:Documentation/power/swsusp-and-swap-files.txt>).

	Right now you may boot without resuming and resume later but in the
	meantime you cannot use the swap partition(s)/file(s) involved in
	suspending. Also in this case you must not use the filesystems
	that were mounted before the suspend. In particular, you MUST NOT
	MOUNT any journaled filesystems mounted before the suspend or they
	will get corrupted in a nasty way.

	For more information take a look at <file:Documentation/power/swsusp.txt>.

	config PM_STD_PARTITION
	string "Default resume partition"
	depends on HIBERNATION
	default ""
	---help---
	The default resume partition is the partition that the suspend-
	to-disk implementation will look for a suspended disk image.

	The partition specified here will be different for almost every user.
	It should be a valid swap partition (at least for now) that is turned
	on before suspending.

	The partition specified can be overridden by specifying:

	resume=/dev/<other device>

	which will set the resume partition to the device specified.

	Note there is currently not a way to specify which device to save the
	suspended image to. It will simply pick the first available swap
	device.

	config PM_SLEEP
	def_bool y
	depends on SUSPEND \|\| HIBERNATE_CALLBACKS

	config PM_SLEEP_SMP
	def_bool y
	depends on SMP
	depends on ARCH_SUSPEND_POSSIBLE \|\| ARCH_HIBERNATION_POSSIBLE
	depends on PM_SLEEP
	select HOTPLUG
	select HOTPLUG_CPU

	config PM_RUNTIME
	bool "Run-time PM core functionality"
	depends on !IA64_HP_SIM
	---help---
	Enable functionality allowing I/O devices to be put into energy-saving
	(low power) states at run time (or autosuspended) after a specified
	period of inactivity and woken up in response to a hardware-generated
	wake-up event or a driver's request.

	Hardware support is generally required for this functionality to work
	and the bus type drivers of the buses the devices are on are
	responsible for the actual handling of the autosuspend requests and
	wake-up events.

	config PM
	def_bool y
	depends on PM_SLEEP \|\| PM_RUNTIME

	config PM_DEBUG
	bool "Power Management Debug Support"
	depends on PM
	---help---
	This option enables various debugging support in the Power Management
	code. This is helpful when debugging and reporting PM bugs, like
	suspend support.

	config PM_ADVANCED_DEBUG
	bool "Extra PM attributes in sysfs for low-level debugging/testing"
	depends on PM_DEBUG
	---help---
	Add extra sysfs attributes allowing one to access some Power Management
	fields of device objects from user space. If you are not a kernel
	developer interested in debugging/testing Power Management, say "no".

	config PM_TEST_SUSPEND
	bool "Test suspend/resume and wakealarm during bootup"
	depends on SUSPEND && PM_DEBUG && RTC_CLASS=y
	---help---
	This option will let you suspend your machine during bootup, and
	make it wake up a few seconds later using an RTC wakeup alarm.
	Enable this with a kernel parameter like "test_suspend=mem".

	You probably want to have your system's RTC driver statically
	linked, ensuring that it's available when this test runs.

	config CAN_PM_TRACE
	def_bool y
	depends on PM_DEBUG && PM_SLEEP

	config PM_TRACE
	bool
	help
	This enables code to save the last PM event point across
	reboot. The architecture needs to support this, x86 for
	example does by saving things in the RTC, see below.

	The architecture specific code must provide the extern
	functions from <linux/resume-trace.h> as well as the
	<asm/resume-trace.h> header with a TRACE_RESUME() macro.

	The way the information is presented is architecture-
	dependent, x86 will print the information during a
	late_initcall.

	config PM_TRACE_RTC
	bool "Suspend/resume event tracing"
	depends on CAN_PM_TRACE
	depends on X86
	select PM_TRACE
	---help---
	This enables some cheesy code to save the last PM event point in the
	RTC across reboots, so that you can debug a machine that just hangs
	during suspend (or more commonly, during resume).

	To use this debugging feature you should attempt to suspend the
	machine, reboot it and then run

	dmesg -s 1000000 \| grep 'hash matches'

	CAUTION: this option will cause your machine's real-time clock to be
	set to an invalid time after a resume.

	config APM_EMULATION
	tristate "Advanced Power Management Emulation"
	depends on PM && SYS_SUPPORTS_APM_EMULATION
	help
	APM is a BIOS specification for saving power using several different
	techniques. This is mostly useful for battery powered laptops with
	APM compliant BIOSes. If you say Y here, the system time will be
	reset after a RESUME operation, the /proc/apm device will provide
	battery status information, and user-space programs will receive
	notification of APM "events" (e.g. battery status change).

	In order to use APM, you will need supporting software. For location
	and more information, read <file:Documentation/power/pm.txt> and the
	Battery Powered Linux mini-HOWTO, available from
	<http://www.tldp.org/docs.html#howto>.

	This driver does not spin down disk drives (see the hdparm(8)
	manpage ("man 8 hdparm") for that), and it doesn't turn off
	VESA-compliant "green" monitors.

	Generally, if you don't have a battery in your machine, there isn't
	much point in using this driver and you should say N. If you get
	random kernel OOPSes or reboots that don't seem to be related to
	anything, try disabling/enabling this option (or disabling/enabling
	APM in your BIOS).

	config ARCH_HAS_OPP
	bool

	config PM_OPP
	bool "Operating Performance Point (OPP) Layer library"
	depends on ARCH_HAS_OPP
	---help---
	SOCs have a standard set of tuples consisting of frequency and
	voltage pairs that the device will support per voltage domain. This
	is called Operating Performance Point or OPP. The actual definitions
	of OPP varies over silicon within the same family of devices.

	OPP layer organizes the data internally using device pointers
	representing individual voltage domains and provides SOC
	implementations a ready to use framework to manage OPPs.
	For more information, read <file:Documentation/power/opp.txt>

	config PM_CLK
	def_bool y
	depends on PM && HAVE_CLK

	config PM_GENERIC_DOMAINS
	bool
	depends on PM