regulator: sysfs attribute reduction (v2)
Clean up the sysfs interface to regulators by only exposing the
attributes that can be properly displayed. For example: when a
particular regulator method is needed to display the value, only
create that attribute when that method exists.
This cleaned-up interface is much more comprehensible. Most
regulators only support a subset of the possible methods, so
often more than half the attributes would be meaningless. Many
"not defined" values are no longer necessary. (But handling
of out-of-range values still looks a bit iffy.)
Documentation is updated to reflect that few of the attributes
are *always* present, and to briefly explain why a regulator may
not have a given attribute.
This adds object code, about a dozen bytes more than was removed
by the preceding patch, but saves a bunch of per-regulator data
associated with the now-removed attributes. So there's a net
reduction in memory footprint.
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 3731f6f..873ef1f 100644
--- a/Documentation/ABI/testing/sysfs-class-regulator
+++ b/Documentation/ABI/testing/sysfs-class-regulator
@@ -3,8 +3,9 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
- state. This holds the regulator output state.
+ Some regulator directories will contain a field called
+ state. This reports the regulator enable status, for
+ regulators which can report that value.
This will be one of the following strings:
@@ -18,7 +19,8 @@
'disabled' means the regulator output is OFF and is not
supplying power to the system..
- 'unknown' means software cannot determine the state.
+ '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.
@@ -53,9 +55,10 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
microvolts. This holds the regulator output voltage setting
- measured in microvolts (i.e. E-6 Volts).
+ measured in microvolts (i.e. E-6 Volts), for regulators
+ which can report that voltage.
NOTE: This value should not be used to determine the regulator
output voltage level as this value is the same regardless of
@@ -67,9 +70,10 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ 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).
+ setting measured in microamps (i.e. E-6 Amps), for regulators
+ which can report that current.
NOTE: This value should not be used to determine the regulator
output current level as this value is the same regardless of
@@ -81,8 +85,9 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
- opmode. This holds the regulator operating mode setting.
+ Some regulator directories will contain a field called
+ opmode. This holds the current regulator operating mode,
+ for regulators which can report it.
The opmode value can be one of the following strings:
@@ -92,7 +97,7 @@
'standby'
'unknown'
- The modes are described in include/linux/regulator/regulator.h
+ The modes are described in include/linux/regulator/consumer.h
NOTE: This value should not be used to determine the regulator
output operating mode as this value is the same regardless of
@@ -104,9 +109,10 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
min_microvolts. This holds the minimum safe working regulator
- output voltage setting for this domain measured in microvolts.
+ output voltage setting for this domain measured in microvolts,
+ for regulators which support voltage constraints.
NOTE: this will return the string 'constraint not defined' if
the power domain has no min microvolts constraint defined by
@@ -118,9 +124,10 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
max_microvolts. This holds the maximum safe working regulator
- output voltage setting for this domain measured in microvolts.
+ output voltage setting for this domain measured in microvolts,
+ for regulators which support voltage constraints.
NOTE: this will return the string 'constraint not defined' if
the power domain has no max microvolts constraint defined by
@@ -132,10 +139,10 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
min_microamps. This holds the minimum safe working regulator
output current limit setting for this domain measured in
- microamps.
+ microamps, for regulators which support current constraints.
NOTE: this will return the string 'constraint not defined' if
the power domain has no min microamps constraint defined by
@@ -147,10 +154,10 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
max_microamps. This holds the maximum safe working regulator
output current limit setting for this domain measured in
- microamps.
+ microamps, for regulators which support current constraints.
NOTE: this will return the string 'constraint not defined' if
the power domain has no max microamps constraint defined by
@@ -185,7 +192,7 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
requested_microamps. This holds the total requested load
current in microamps for this regulator from all its consumer
devices.
@@ -204,125 +211,102 @@
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories 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.
+ the system is suspended to memory, for voltage regulators
+ implementing suspend voltage configuration constraints.
What: /sys/class/regulator/.../suspend_disk_microvolts
Date: May 2008
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories 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.
+ the system is suspended to disk, for voltage regulators
+ implementing suspend voltage configuration constraints.
What: /sys/class/regulator/.../suspend_standby_microvolts
Date: May 2008
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories 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.
+ the system is suspended to standby, for voltage regulators
+ implementing suspend voltage configuration constraints.
What: /sys/class/regulator/.../suspend_mem_mode
Date: May 2008
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories 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.
+ memory, for regulators implementing suspend mode
+ configuration constraints.
What: /sys/class/regulator/.../suspend_disk_mode
Date: May 2008
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories 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.
+ setting for this domain when the system is suspended to disk,
+ for regulators implementing suspend mode configuration
+ constraints.
What: /sys/class/regulator/.../suspend_standby_mode
Date: May 2008
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories 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.
+ standby, for regulators implementing suspend mode
+ configuration constraints.
What: /sys/class/regulator/.../suspend_mem_state
Date: May 2008
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
suspend_mem_state. This holds the regulator operating state
- when suspended to memory.
+ when suspended to memory, for regulators implementing suspend
+ configuration constraints.
- This will be one of the following strings:
-
- 'enabled'
- 'disabled'
- 'not defined'
+ This will be one of the same strings reported by
+ the "state" attribute.
What: /sys/class/regulator/.../suspend_disk_state
Date: May 2008
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
suspend_disk_state. This holds the regulator operating state
- when suspended to disk.
+ when suspended to disk, for regulators implementing
+ suspend configuration constraints.
- This will be one of the following strings:
-
- 'enabled'
- 'disabled'
- 'not defined'
+ This will be one of the same strings reported by
+ the "state" attribute.
What: /sys/class/regulator/.../suspend_standby_state
Date: May 2008
KernelVersion: 2.6.26
Contact: Liam Girdwood <lrg@slimlogic.co.uk>
Description:
- Each regulator directory will contain a field called
+ Some regulator directories will contain a field called
suspend_standby_state. This holds the regulator operating
- state when suspended to standby.
+ state when suspended to standby, for regulators implementing
+ suspend configuration constraints.
- This will be one of the following strings:
-
- 'enabled'
- 'disabled'
- 'not defined'
+ This will be one of the same strings reported by
+ the "state" attribute.