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path: root/drivers/regulator/core.c
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Diffstat (limited to 'drivers/regulator/core.c')
-rw-r--r--drivers/regulator/core.c109
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);
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-04 23:59:21 +0000