struct device_attribute *attr, char *buf)
{
struct regulator_dev *rdev = dev_get_drvdata(dev);
+ ssize_t ret;
+
+ mutex_lock(&rdev->mutex);
+ ret = regulator_print_state(buf, _regulator_is_enabled(rdev));
+ mutex_unlock(&rdev->mutex);
- return regulator_print_state(buf, _regulator_is_enabled(rdev));
+ return ret;
}
static DEVICE_ATTR(state, 0444, regulator_state_show, NULL);
}
EXPORT_SYMBOL_GPL(regulator_put);
+static int _regulator_can_change_status(struct regulator_dev *rdev)
+{
+ if (!rdev->constraints)
+ return 0;
+
+ if (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_STATUS)
+ return 1;
+ else
+ return 0;
+}
+
/* locks held by regulator_enable() */
static int _regulator_enable(struct regulator_dev *rdev)
{
- int ret = -EINVAL;
-
- if (!rdev->constraints) {
- printk(KERN_ERR "%s: %s has no constraints\n",
- __func__, rdev->desc->name);
- return ret;
- }
+ int ret;
/* do we need to enable the supply regulator first */
if (rdev->supply) {
}
/* check voltage and requested load before enabling */
- if (rdev->desc->ops->enable) {
+ if (rdev->constraints &&
+ (rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_DRMS))
+ drms_uA_update(rdev);
- if (rdev->constraints &&
- (rdev->constraints->valid_ops_mask &
- REGULATOR_CHANGE_DRMS))
- drms_uA_update(rdev);
-
- ret = rdev->desc->ops->enable(rdev);
- if (ret < 0) {
- printk(KERN_ERR "%s: failed to enable %s: %d\n",
+ if (rdev->use_count == 0) {
+ /* The regulator may on if it's not switchable or left on */
+ ret = _regulator_is_enabled(rdev);
+ if (ret == -EINVAL || ret == 0) {
+ if (!_regulator_can_change_status(rdev))
+ return -EPERM;
+
+ if (rdev->desc->ops->enable) {
+ ret = rdev->desc->ops->enable(rdev);
+ if (ret < 0)
+ return ret;
+ } else {
+ return -EINVAL;
+ }
+ } else if (ret < 0) {
+ printk(KERN_ERR "%s: is_enabled() failed for %s: %d\n",
__func__, rdev->desc->name, ret);
return ret;
}
- rdev->use_count++;
- return ret;
+ /* Fallthrough on positive return values - already enabled */
}
- return ret;
+ rdev->use_count++;
+
+ return 0;
}
/**
if (rdev->use_count == 1 && !rdev->constraints->always_on) {
/* we are last user */
- if (rdev->desc->ops->disable) {
+ if (_regulator_can_change_status(rdev) &&
+ rdev->desc->ops->disable) {
ret = rdev->desc->ops->disable(rdev);
if (ret < 0) {
printk(KERN_ERR "%s: failed to disable %s\n",
static int _regulator_is_enabled(struct regulator_dev *rdev)
{
- int ret;
-
- mutex_lock(&rdev->mutex);
-
/* sanity check */
- if (!rdev->desc->ops->is_enabled) {
- ret = -EINVAL;
- goto out;
- }
+ if (!rdev->desc->ops->is_enabled)
+ return -EINVAL;
- ret = rdev->desc->ops->is_enabled(rdev);
-out:
- mutex_unlock(&rdev->mutex);
- return ret;
+ return rdev->desc->ops->is_enabled(rdev);
}
/**
*/
int regulator_is_enabled(struct regulator *regulator)
{
- return _regulator_is_enabled(regulator->rdev);
+ int ret;
+
+ mutex_lock(®ulator->rdev->mutex);
+ ret = _regulator_is_enabled(regulator->rdev);
+ mutex_unlock(®ulator->rdev->mutex);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(regulator_is_enabled);