regulator: Add API to re-apply voltage to hardware
When cooperating with an external control source the regulator setup
may be changed underneath the API. Currently consumers can just redo
the regulator_set_voltage() to restore a previously set configuration
but provide an explicit API for doing this as optimsations in the
regulator_set_voltage() implementation will shortly prevent that.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 3d72cc8..a12cba3 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1727,6 +1727,53 @@
}
EXPORT_SYMBOL_GPL(regulator_set_voltage);
+/**
+ * regulator_sync_voltage - re-apply last regulator output voltage
+ * @regulator: regulator source
+ *
+ * Re-apply the last configured voltage. This is intended to be used
+ * where some external control source the consumer is cooperating with
+ * has caused the configured voltage to change.
+ */
+int regulator_sync_voltage(struct regulator *regulator)
+{
+ struct regulator_dev *rdev = regulator->rdev;
+ int ret, min_uV, max_uV;
+
+ mutex_lock(&rdev->mutex);
+
+ if (!rdev->desc->ops->set_voltage &&
+ !rdev->desc->ops->set_voltage_sel) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* This is only going to work if we've had a voltage configured. */
+ if (!regulator->min_uV && !regulator->max_uV) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ min_uV = regulator->min_uV;
+ max_uV = regulator->max_uV;
+
+ /* This should be a paranoia check... */
+ ret = regulator_check_voltage(rdev, &min_uV, &max_uV);
+ if (ret < 0)
+ goto out;
+
+ ret = regulator_check_consumers(rdev, &min_uV, &max_uV);
+ if (ret < 0)
+ goto out;
+
+ ret = _regulator_do_set_voltage(rdev, min_uV, max_uV);
+
+out:
+ mutex_unlock(&rdev->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_sync_voltage);
+
static int _regulator_get_voltage(struct regulator_dev *rdev)
{
int sel;