3 files changed, 111 insertions, 9 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-regulator b/Documentation/ABI/testing/sysfs-class-regulator
index 873ef1fc1569..e091fa873792 100644
--- a/Documentation/ABI/testing/sysfs-class-regulator
+++ b/Documentation/ABI/testing/sysfs-class-regulator
@@ -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
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index f511a406fcaa..0ff95c3ccf5b 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -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) {
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 2dae05705f13..6e957aae7629 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -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);