regulator: add get_status()
Based on previous LKML discussions:
* Update docs for regulator sysfs class attributes to highlight
the fact that all current attributes are intended to be control
inputs, including notably "state" and "opmode" which previously
implied otherwise.
* Define a new regulator driver get_status() method, which is the
first method reporting regulator outputs instead of inputs.
It can report on/off and error status; or instead of simply
"on", report the actual operating mode.
For the moment, this is a sysfs-only interface, not accessible to
regulator clients. Such clients can use the current notification
interfaces to detect errors, if the regulator reports them.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/Documentation/ABI/testing/sysfs-class-regulator b/Documentation/ABI/testing/sysfs-class-regulator
index 873ef1f..e091fa8 100644
--- a/Documentation/ABI/testing/sysfs-class-regulator
+++ b/Documentation/ABI/testing/sysfs-class-regulator
@@ -4,8 +4,8 @@
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
Some regulator directories will contain a field called
- state. This reports the regulator enable status, for
- regulators which can report that value.
+ state. This reports the regulator enable control, for
+ regulators which can report that input value.
This will be one of the following strings:
@@ -14,16 +14,54 @@
'unknown'
'enabled' means the regulator output is ON and is supplying
- power to the system.
+ power to the system (assuming no error prevents it).
'disabled' means the regulator output is OFF and is not
- supplying power to the system..
+ supplying power to the system (unless some non-Linux
+ control has enabled it).
'unknown' means software cannot determine the state, or
the reported state is invalid.
NOTE: this field can be used in conjunction with microvolts
- and microamps to determine regulator output levels.
+ or microamps to determine configured regulator output levels.
+
+
+What: /sys/class/regulator/.../status
+Description:
+ Some regulator directories will contain a field called
+ "status". This reports the current regulator status, for
+ regulators which can report that output value.
+
+ This will be one of the following strings:
+
+ off
+ on
+ error
+ fast
+ normal
+ idle
+ standby
+
+ "off" means the regulator is not supplying power to the
+ system.
+
+ "on" means the regulator is supplying power to the system,
+ and the regulator can't report a detailed operation mode.
+
+ "error" indicates an out-of-regulation status such as being
+ disabled due to thermal shutdown, or voltage being unstable
+ because of problems with the input power supply.
+
+ "fast", "normal", "idle", and "standby" are all detailed
+ regulator operation modes (described elsewhere). They
+ imply "on", but provide more detail.
+
+ Note that regulator status is a function of many inputs,
+ not limited to control inputs from Linux. For example,
+ the actual load presented may trigger "error" status; or
+ a regulator may be enabled by another user, even though
+ Linux did not enable it.
What: /sys/class/regulator/.../type
@@ -58,7 +96,7 @@
Some regulator directories will contain a field called
microvolts. This holds the regulator output voltage setting
measured in microvolts (i.e. E-6 Volts), for regulators
- which can report that voltage.
+ which can report the control input for voltage.
NOTE: This value should not be used to determine the regulator
output voltage level as this value is the same regardless of
@@ -73,7 +111,7 @@
Some regulator directories will contain a field called
microamps. This holds the regulator output current limit
setting measured in microamps (i.e. E-6 Amps), for regulators
- which can report that current.
+ which can report the control input for a current limit.
NOTE: This value should not be used to determine the regulator
output current level as this value is the same regardless of
@@ -87,7 +125,7 @@
Description:
Some regulator directories will contain a field called
opmode. This holds the current regulator operating mode,
- for regulators which can report it.
+ for regulators which can report that control input value.
The opmode value can be one of the following strings:
@@ -101,7 +139,8 @@
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.
+ whether the regulator is enabled or disabled. A "status"
+ attribute may be available to determine the actual mode.
What: /sys/class/regulator/.../min_microvolts