Squashandroid-20111012

Change-Id: If0ae9fa8067740ab2ede33703c79ec134f204a5e

1 files changed, 85 insertions, 24 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 2248087b9be..0d78dfa7476 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -60,15 +60,17 @@ struct regulator {
 	char *supply_name;
 	struct device_attribute dev_attr;
 	struct regulator_dev *rdev;
+	int use;
 };
 
 static int _regulator_is_enabled(struct regulator_dev *rdev);
-static int _regulator_disable(struct regulator_dev *rdev);
+static int _regulator_disable(struct regulator_dev *rdev,
+		struct regulator_dev **supply_rdev_ptr);
 static int _regulator_get_voltage(struct regulator_dev *rdev);
 static int _regulator_get_current_limit(struct regulator_dev *rdev);
 static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
 static void _notifier_call_chain(struct regulator_dev *rdev,
-				  unsigned long event, void *data);
+				  unsigned long event, void *data, int lock_sublevel);
 
 static const char *rdev_get_name(struct regulator_dev *rdev)
 {
@@ -517,6 +519,32 @@ static ssize_t regulator_suspend_standby_state_show(struct device *dev,
 static DEVICE_ATTR(suspend_standby_state, 0444,
 		regulator_suspend_standby_state_show, NULL);
 
+static ssize_t regulator_use_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct regulator_dev *rdev = dev_get_drvdata(dev);
+	struct regulator *reg;
+	size_t size = 0;
+
+	if (rdev->use_count == 0)
+		return sprintf(buf, "no users\n");
+
+	list_for_each_entry(reg, &rdev->consumer_list, list) {
+		if (!reg->use)
+			continue;
+
+		if (reg->dev != NULL)
+			size += sprintf((buf + size), "%s (%d) ",
+					dev_name(reg->dev), reg->use);
+		else
+			size += sprintf((buf + size), "unknown (%d) ",
+					reg->use);
+	}
+	size += sprintf((buf + size), "\n");
+
+	return size;
+}
+static DEVICE_ATTR(use, 0444, regulator_use_show, NULL);
 
 /*
  * These are the only attributes are present for all regulators.
@@ -1262,13 +1290,15 @@ static int _regulator_enable(struct regulator_dev *rdev)
 {
 	int ret, delay;
 
-	/* do we need to enable the supply regulator first */
-	if (rdev->supply) {
-		ret = _regulator_enable(rdev->supply);
-		if (ret < 0) {
-			printk(KERN_ERR "%s: failed to enable %s: %d\n",
-			       __func__, rdev_get_name(rdev), ret);
-			return ret;
+	if (rdev->use_count == 0) {
+		/* do we need to enable the supply regulator first */
+		if (rdev->supply) {
+			ret = _regulator_enable(rdev->supply);
+			if (ret < 0) {
+				printk(KERN_ERR "%s: failed to enable %s: %d\n",
+				       __func__, rdev_get_name(rdev), ret);
+				return ret;
+			}
 		}
 	}
 
@@ -1344,14 +1374,19 @@ int regulator_enable(struct regulator *regulator)
 	mutex_lock(&rdev->mutex);
 	ret = _regulator_enable(rdev);
 	mutex_unlock(&rdev->mutex);
+	if (ret == 0)
+		regulator->use++;
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_enable);
 
 /* locks held by regulator_disable() */
-static int _regulator_disable(struct regulator_dev *rdev)
+static int _regulator_disable(struct regulator_dev *rdev,
+		struct regulator_dev **supply_rdev_ptr)
 {
 	int ret = 0;
+	*supply_rdev_ptr = NULL;
 
 	if (WARN(rdev->use_count <= 0,
 			"unbalanced disables for %s\n",
@@ -1373,12 +1408,11 @@ static int _regulator_disable(struct regulator_dev *rdev)
 			}
 
 			_notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE,
-					     NULL);
+					     NULL, 0);
 		}
 
 		/* decrease our supplies ref count and disable if required */
-		if (rdev->supply)
-			_regulator_disable(rdev->supply);
+		*supply_rdev_ptr = rdev->supply;
 
 		rdev->use_count = 0;
 	} else if (rdev->use_count > 1) {
@@ -1408,17 +1442,32 @@ static int _regulator_disable(struct regulator_dev *rdev)
 int regulator_disable(struct regulator *regulator)
 {
 	struct regulator_dev *rdev = regulator->rdev;
+	struct regulator_dev *supply_rdev = NULL;
 	int ret = 0;
 
 	mutex_lock(&rdev->mutex);
-	ret = _regulator_disable(rdev);
+	ret = _regulator_disable(rdev, &supply_rdev);
 	mutex_unlock(&rdev->mutex);
+
+	/* decrease our supplies ref count and disable if required */
+	while (supply_rdev != NULL) {
+		rdev = supply_rdev;
+
+		mutex_lock(&rdev->mutex);
+		_regulator_disable(rdev, &supply_rdev);
+		mutex_unlock(&rdev->mutex);
+	}
+
+	if (ret == 0)
+		regulator->use--;
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_disable);
 
 /* locks held by regulator_force_disable() */
-static int _regulator_force_disable(struct regulator_dev *rdev)
+static int _regulator_force_disable(struct regulator_dev *rdev,
+		struct regulator_dev **supply_rdev_ptr)
 {
 	int ret = 0;
 
@@ -1433,12 +1482,11 @@ static int _regulator_force_disable(struct regulator_dev *rdev)
 		}
 		/* notify other consumers that power has been forced off */
 		_notifier_call_chain(rdev, REGULATOR_EVENT_FORCE_DISABLE |
-			REGULATOR_EVENT_DISABLE, NULL);
+			REGULATOR_EVENT_DISABLE, NULL, 0);
 	}
 
 	/* decrease our supplies ref count and disable if required */
-	if (rdev->supply)
-		_regulator_disable(rdev->supply);
+	*supply_rdev_ptr = rdev->supply;
 
 	rdev->use_count = 0;
 	return ret;
@@ -1455,12 +1503,17 @@ static int _regulator_force_disable(struct regulator_dev *rdev)
  */
 int regulator_force_disable(struct regulator *regulator)
 {
+	struct regulator_dev *supply_rdev = NULL;
 	int ret;
 
 	mutex_lock(&regulator->rdev->mutex);
 	regulator->uA_load = 0;
-	ret = _regulator_force_disable(regulator->rdev);
+	ret = _regulator_force_disable(regulator->rdev, &supply_rdev);
 	mutex_unlock(&regulator->rdev->mutex);
+
+	if (supply_rdev)
+		regulator_disable(get_device_regulator(rdev_get_dev(supply_rdev)));
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(regulator_force_disable);
@@ -1617,7 +1670,7 @@ int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV)
 	ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV);
 
 out:
-	_notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE, NULL);
+	_notifier_call_chain(rdev, REGULATOR_EVENT_VOLTAGE_CHANGE, NULL, 0);
 	mutex_unlock(&rdev->mutex);
 	return ret;
 }
@@ -1930,19 +1983,23 @@ EXPORT_SYMBOL_GPL(regulator_unregister_notifier);
 
 /* notify regulator consumers and downstream regulator consumers.
  * Note mutex must be held by caller.
+ * lock_sublevel should always be 0, only used for recursive calls.
  */
 static void _notifier_call_chain(struct regulator_dev *rdev,
-				  unsigned long event, void *data)
+				  unsigned long event, void *data, int lock_sublevel)
 {
 	struct regulator_dev *_rdev;
 
 	/* call rdev chain first */
 	blocking_notifier_call_chain(&rdev->notifier, event, NULL);
 
+	/* increase sublevel before stepping into nested regulators */
+	lock_sublevel++;
+
 	/* now notify regulator we supply */
 	list_for_each_entry(_rdev, &rdev->supply_list, slist) {
-		mutex_lock(&_rdev->mutex);
-		_notifier_call_chain(_rdev, event, data);
+		mutex_lock_nested(&_rdev->mutex, lock_sublevel);
+		_notifier_call_chain(_rdev, event, data, lock_sublevel);
 		mutex_unlock(&_rdev->mutex);
 	}
 }
@@ -2097,7 +2154,7 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free);
 int regulator_notifier_call_chain(struct regulator_dev *rdev,
 				  unsigned long event, void *data)
 {
-	_notifier_call_chain(rdev, event, data);
+	_notifier_call_chain(rdev, event, data, 0);
 	return NOTIFY_DONE;
 
 }
@@ -2137,6 +2194,10 @@ static int add_regulator_attributes(struct regulator_dev *rdev)
 	struct regulator_ops	*ops = rdev->desc->ops;
 	int			status = 0;
 
+	status = device_create_file(dev, &dev_attr_use);
+	if (status < 0)
+		dev_warn(dev, "Create sysfs file \"use\" failed");
+
 	/* some attributes need specific methods to be displayed */
 	if (ops->get_voltage) {
 		status = device_create_file(dev, &dev_attr_microvolts);