Commit 853116a1 authored by David Brownell's avatar David Brownell Committed by Liam Girdwood
Browse files

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: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarLiam Girdwood <lrg@slimlogic.co.uk>
parent 93e14baa
......@@ -4,8 +4,8 @@ KernelVersion: 2.6.26
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 @@ Description:
'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 @@ Description:
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 @@ Description:
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 @@ Contact: Liam Girdwood <lrg@slimlogic.co.uk>
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 @@ Description:
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
......
......@@ -312,6 +312,47 @@ static ssize_t regulator_state_show(struct device *dev,
}
static DEVICE_ATTR(state, 0444, regulator_state_show, NULL);
static ssize_t regulator_status_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct regulator_dev *rdev = dev_get_drvdata(dev);
int status;
char *label;
status = rdev->desc->ops->get_status(rdev);
if (status < 0)
return status;
switch (status) {
case REGULATOR_STATUS_OFF:
label = "off";
break;
case REGULATOR_STATUS_ON:
label = "on";
break;
case REGULATOR_STATUS_ERROR:
label = "error";
break;
case REGULATOR_STATUS_FAST:
label = "fast";
break;
case REGULATOR_STATUS_NORMAL:
label = "normal";
break;
case REGULATOR_STATUS_IDLE:
label = "idle";
break;
case REGULATOR_STATUS_STANDBY:
label = "standby";
break;
default:
return -ERANGE;
}
return sprintf(buf, "%s\n", label);
}
static DEVICE_ATTR(status, 0444, regulator_status_show, NULL);
static ssize_t regulator_min_uA_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
......@@ -1744,6 +1785,11 @@ static int add_regulator_attributes(struct regulator_dev *rdev)
if (status < 0)
return status;
}
if (ops->get_status) {
status = device_create_file(dev, &dev_attr_status);
if (status < 0)
return status;
}
/* some attributes are type-specific */
if (rdev->desc->type == REGULATOR_CURRENT) {
......
......@@ -21,6 +21,17 @@
struct regulator_dev;
struct regulator_init_data;
enum regulator_status {
REGULATOR_STATUS_OFF,
REGULATOR_STATUS_ON,
REGULATOR_STATUS_ERROR,
/* fast/normal/idle/standby are flavors of "on" */
REGULATOR_STATUS_FAST,
REGULATOR_STATUS_NORMAL,
REGULATOR_STATUS_IDLE,
REGULATOR_STATUS_STANDBY,
};
/**
* struct regulator_ops - regulator operations.
*
......@@ -72,6 +83,12 @@ struct regulator_ops {
int (*set_mode) (struct regulator_dev *, unsigned int mode);
unsigned int (*get_mode) (struct regulator_dev *);
/* report regulator status ... most other accessors report
* control inputs, this reports results of combining inputs
* from Linux (and other sources) with the actual load.
*/
int (*get_status)(struct regulator_dev *);
/* get most efficient regulator operating mode for load */
unsigned int (*get_optimum_mode) (struct regulator_dev *, int input_uV,
int output_uV, int load_uA);
......
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