regulator: core: Allow regulators to provide a voltage to selector mapping

In order to allow more drivers to factor things out into data allow
drivers to provide a mapping function to convert voltages into selectors.
This allows any driver to use set_voltage_sel(). The existing mapping
based on iterating over list_voltage() is provided as an operation which
can be assigned to the new map_voltage() function though for ease of
transition it is treated as the default.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 8160bc8..13aa852 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -46,6 +46,7 @@
  *               The driver should select the voltage closest to min_uV.
  * @set_voltage_sel: Set the voltage for the regulator using the specified
  *                   selector.
+ * @map_voltage: Convert a voltage into a selector
  * @get_voltage: Return the currently configured voltage for the regulator.
  * @get_voltage_sel: Return the currently configured voltage selector for the
  *                   regulator.
@@ -91,6 +92,7 @@
 	/* get/set regulator voltage */
 	int (*set_voltage) (struct regulator_dev *, int min_uV, int max_uV,
 			    unsigned *selector);
+	int (*map_voltage)(struct regulator_dev *, int min_uV, int max_uV);
 	int (*set_voltage_sel) (struct regulator_dev *, unsigned selector);
 	int (*get_voltage) (struct regulator_dev *);
 	int (*get_voltage_sel) (struct regulator_dev *);
@@ -260,6 +262,8 @@
 
 int regulator_mode_to_status(unsigned int);
 
+int regulator_map_voltage_iterate(struct regulator_dev *rdev,
+				  int min_uV, int max_uV);
 int regulator_get_voltage_sel_regmap(struct regulator_dev *rdev);
 int regulator_set_voltage_sel_regmap(struct regulator_dev *rdev, unsigned sel);
 int regulator_is_enabled_regmap(struct regulator_dev *rdev);