[PATCH 4/6] regulator: Add operation to let drivers select vsel register

[Frieder Schrempf <frieder@fris.de>]

From: Frieder Schrempf <frieder.schrempf@kontron.de>

There are regulators that use multiple registers for storing the
voltage. Add a get_reg_voltage_sel member to struct regulator_ops in
order to let drivers register a function that returns the currently
used register.

The pca9450 driver will be a user of this as the LDO5 regulator of
that chip uses two different control registers depending on the
state of an external signal.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
 drivers/regulator/helpers.c      | 16 ++++++++++++++--
 include/linux/regulator/driver.h |  5 +++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/regulator/helpers.c b/drivers/regulator/helpers.c
index ad2237a95572..e629b0bea3d0 100644
--- a/drivers/regulator/helpers.c
+++ b/drivers/regulator/helpers.c
@@ -223,6 +223,16 @@ int regulator_set_voltage_sel_pickable_regmap(struct regulator_dev *rdev,
 }
 EXPORT_SYMBOL_GPL(regulator_set_voltage_sel_pickable_regmap);
 
+unsigned int regulator_get_hwreg_voltage_sel_regmap(struct regulator_dev *rdev)
+{
+	const struct regulator_ops *ops = rdev->desc->ops;
+
+	if (ops->get_reg_voltage_sel)
+		return ops->get_reg_voltage_sel(rdev);
+
+	return rdev->desc->vsel_reg;
+}
+
 /**
  * regulator_get_voltage_sel_regmap - standard get_voltage_sel for regmap users
  *
@@ -234,10 +244,11 @@ EXPORT_SYMBOL_GPL(regulator_set_voltage_sel_pickable_regmap);
  */
 int regulator_get_voltage_sel_regmap(struct regulator_dev *rdev)
 {
+	unsigned int vsel_reg = regulator_get_hwreg_voltage_sel_regmap(rdev);
 	unsigned int val;
 	int ret;
 
-	ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
+	ret = regmap_read(rdev->regmap, vsel_reg, &val);
 	if (ret != 0)
 		return ret;
 
@@ -260,11 +271,12 @@ EXPORT_SYMBOL_GPL(regulator_get_voltage_sel_regmap);
  */
 int regulator_set_voltage_sel_regmap(struct regulator_dev *rdev, unsigned sel)
 {
+	unsigned int vsel_reg = regulator_get_hwreg_voltage_sel_regmap(rdev);
 	int ret;
 
 	sel <<= ffs(rdev->desc->vsel_mask) - 1;
 
-	ret = regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
+	ret = regmap_update_bits(rdev->regmap, vsel_reg,
 				  rdev->desc->vsel_mask, sel);
 	if (ret)
 		return ret;
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index d3b4a3d4514a..c9953b2f63d5 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -77,6 +77,10 @@ enum regulator_detection_severity {
  * @get_voltage_sel: Return the currently configured voltage selector for the
  *                   regulator; return -ENOTRECOVERABLE if regulator can't
  *                   be read at bootup and hasn't been set yet.
+ * @get_reg_voltage_sel: Return the register used for getting/setting the
+ *                       voltage of the regulator. This is useful if the
+ *                       regulator uses multiple registers internally, switched
+ *                       by some condition like the state of an external signal.
  * @list_voltage: Return one of the supported voltages, in microvolts; zero
  *	if the selector indicates a voltage that is unusable on this system;
  *	or negative errno.  Selectors range from zero to one less than
@@ -168,6 +172,7 @@ struct regulator_ops {
 	int (*set_voltage_sel) (struct regulator_dev *, unsigned selector);
 	int (*get_voltage) (struct regulator_dev *);
 	int (*get_voltage_sel) (struct regulator_dev *);
+	unsigned int (*get_reg_voltage_sel) (struct regulator_dev *);
 
 	/* get/set regulator current  */
 	int (*set_current_limit) (struct regulator_dev *,
-- 
2.39.1