regulator: documentation - ABI

This adds documentation describing the sysfs ABI used by the regulator
framework.
Signed-off-by: NLiam Girdwood <lg@opensource.wolfsonmicro.com>

Documentation/ABI/testing/sysfs-class-regulator

+What:		/sys/class/regulator/.../state
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		state. This holds the regulator output state.
+
+		This will be one of the following strings:
+
+		'enabled'
+		'disabled'
+		'unknown'
+
+		'enabled' means the regulator output is ON and is supplying
+		power to the system.
+
+		'disabled' means the regulator output is OFF and is not
+		supplying power to the system..
+
+		'unknown' means software cannot determine the state.
+
+		NOTE: this field can be used in conjunction with microvolts
+		and microamps to determine regulator output levels.
+
+
+What:		/sys/class/regulator/.../type
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		type. This holds the regulator type.
+
+		This will be one of the following strings:
+
+		'voltage'
+		'current'
+		'unknown'
+
+		'voltage' means the regulator output voltage can be controlled
+		by software.
+
+		'current' means the regulator output current limit can be
+		controlled by software.
+
+		'unknown' means software cannot control either voltage or
+		current limit.
+
+
+What:		/sys/class/regulator/.../microvolts
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		microvolts. This holds the regulator output voltage setting
+		measured in microvolts (i.e. E-6 Volts).
+
+		NOTE: This value should not be used to determine the regulator
+		output voltage level as this value is the same regardless of
+		whether the regulator is enabled or disabled.
+
+
+What:		/sys/class/regulator/.../microamps
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		microamps. This holds the regulator output current limit
+		setting measured in microamps (i.e. E-6 Amps).
+
+		NOTE: This value should not be used to determine the regulator
+		output current level as this value is the same regardless of
+		whether the regulator is enabled or disabled.
+
+
+What:		/sys/class/regulator/.../opmode
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		opmode. This holds the regulator operating mode setting.
+
+		The opmode value can be one of the following strings:
+
+		'fast'
+		'normal'
+		'idle'
+		'standby'
+		'unknown'
+
+		The modes are described in include/linux/regulator/regulator.h
+
+		NOTE: This value should not be used to determine the regulator
+		output operating mode as this value is the same regardless of
+		whether the regulator is enabled or disabled.
+
+
+What:		/sys/class/regulator/.../min_microvolts
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		min_microvolts. This holds the minimum safe working regulator
+		output voltage setting for this domain measured in microvolts.
+
+		NOTE: this will return the string 'constraint not defined' if
+		the power domain has no min microvolts constraint defined by
+		platform code.
+
+
+What:		/sys/class/regulator/.../max_microvolts
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		max_microvolts. This holds the maximum safe working regulator
+		output voltage setting for this domain measured in microvolts.
+
+		NOTE: this will return the string 'constraint not defined' if
+		the power domain has no max microvolts constraint defined by
+		platform code.
+
+
+What:		/sys/class/regulator/.../min_microamps
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		min_microamps. This holds the minimum safe working regulator
+		output current limit setting for this domain measured in
+		microamps.
+
+		NOTE: this will return the string 'constraint not defined' if
+		the power domain has no min microamps constraint defined by
+		platform code.
+
+
+What:		/sys/class/regulator/.../max_microamps
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		max_microamps. This holds the maximum safe working regulator
+		output current limit setting for this domain measured in
+		microamps.
+
+		NOTE: this will return the string 'constraint not defined' if
+		the power domain has no max microamps constraint defined by
+		platform code.
+
+
+What:		/sys/class/regulator/.../num_users
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		num_users. This holds the number of consumer devices that
+		have called regulator_enable() on this regulator.
+
+
+What:		/sys/class/regulator/.../requested_microamps
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		requested_microamps. This holds the total requested load
+		current in microamps for this regulator from all its consumer
+		devices.
+
+
+What:		/sys/class/regulator/.../parent
+Date:		April 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Some regulator directories will contain a link called parent.
+		This points to the parent or supply regulator if one exists.
+
+What:		/sys/class/regulator/.../suspend_mem_microvolts
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_mem_microvolts. This holds the regulator output
+		voltage setting for this domain measured in microvolts when
+		the system is suspended to memory.
+
+		NOTE: this will return the string 'not defined' if
+		the power domain has no suspend to memory voltage defined by
+		platform code.
+
+What:		/sys/class/regulator/.../suspend_disk_microvolts
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_disk_microvolts. This holds the regulator output
+		voltage setting for this domain measured in microvolts when
+		the system is suspended to disk.
+
+		NOTE: this will return the string 'not defined' if
+		the power domain has no suspend to disk voltage defined by
+		platform code.
+
+What:		/sys/class/regulator/.../suspend_standby_microvolts
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_standby_microvolts. This holds the regulator output
+		voltage setting for this domain measured in microvolts when
+		the system is suspended to standby.
+
+		NOTE: this will return the string 'not defined' if
+		the power domain has no suspend to standby voltage defined by
+		platform code.
+
+What:		/sys/class/regulator/.../suspend_mem_mode
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_mem_mode. This holds the regulator operating mode
+		setting for this domain when the system is suspended to
+		memory.
+
+		NOTE: this will return the string 'not defined' if
+		the power domain has no suspend to memory mode defined by
+		platform code.
+
+What:		/sys/class/regulator/.../suspend_disk_mode
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_disk_mode. This holds the regulator operating mode
+		setting for this domain when the system is suspended to disk.
+
+		NOTE: this will return the string 'not defined' if
+		the power domain has no suspend to disk mode defined by
+		platform code.
+
+What:		/sys/class/regulator/.../suspend_standby_mode
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_standby_mode. This holds the regulator operating mode
+		setting for this domain when the system is suspended to
+		standby.
+
+		NOTE: this will return the string 'not defined' if
+		the power domain has no suspend to standby mode defined by
+		platform code.
+
+What:		/sys/class/regulator/.../suspend_mem_state
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_mem_state. This holds the regulator operating state
+		when suspended to memory.
+
+		This will be one of the following strings:
+
+		'enabled'
+		'disabled'
+		'not defined'
+
+What:		/sys/class/regulator/.../suspend_disk_state
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_disk_state. This holds the regulator operating state
+		when suspended to disk.
+
+		This will be one of the following strings:
+
+		'enabled'
+		'disabled'
+		'not defined'
+
+What:		/sys/class/regulator/.../suspend_standby_state
+Date:		May 2008
+KernelVersion:	2.6.26
+Contact:	Liam Girdwood <lg@opensource.wolfsonmicro.com>
+Description:
+		Each regulator directory will contain a field called
+		suspend_standby_state. This holds the regulator operating
+		state when suspended to standby.
+
+		This will be one of the following strings:
+
+		'enabled'
+		'disabled'
+		'not defined'