regulators: add regulator_can_change_voltage() function

Introduce a regulator_can_change_voltage() function for the subsytems or
drivers which might check if applying voltage change is possible and use
special workaround code when the driver is used with fixed regulators or
regulators with disabled ability to change the voltage.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index e872c8be080ed427a2e546efffee50c12acdd9fe..59e08633372a074380e337af4fd7bce0e7b1d72c 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1866,6 +1866,28 @@ int regulator_is_enabled(struct regulator *regulator)
 }
 EXPORT_SYMBOL_GPL(regulator_is_enabled);
 
+/**
+ * regulator_can_change_voltage - check if regulator can change voltage
+ * @regulator: regulator source
+ *
+ * Returns positive if the regulator driver backing the source/client
+ * can change its voltage, false otherwise. Usefull for detecting fixed
+ * or dummy regulators and disabling voltage change logic in the client
+ * driver.
+ */
+int regulator_can_change_voltage(struct regulator *regulator)
+{
+       struct regulator_dev    *rdev = regulator->rdev;
+
+       if (rdev->constraints &&
+           rdev->constraints->valid_ops_mask & REGULATOR_CHANGE_VOLTAGE &&
+           rdev->desc->n_voltages > 1)
+               return 1;
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(regulator_can_change_voltage);
+
 /**
  * regulator_count_voltages - count regulator_list_voltage() selectors
  * @regulator: regulator source

diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index c43cd3556b1f5b789bae79de586f7e85a4cafacc..5d0f7c10bef1cb1ae86574b1c170574732cb5a77 100644 (file)
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -160,6 +160,7 @@ int regulator_bulk_force_disable(int num_consumers,
 void regulator_bulk_free(int num_consumers,
                         struct regulator_bulk_data *consumers);
 
+int regulator_can_change_voltage(struct regulator *regulator);
 int regulator_count_voltages(struct regulator *regulator);
 int regulator_list_voltage(struct regulator *regulator, unsigned selector);
 int regulator_is_supported_voltage(struct regulator *regulator,