[PATCH v4 10/16] regulator: helpers: Export helper voltage listing

[Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>]

Some drivers need to translate voltage values to selectors prior regulator
registration. Currently a regulator_desc based list_voltages helper is only
exported for regulators using the linear_ranges. Export similar helper also
for regulators using simple linear mapping.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---
Changes since v3:
 - No changes
 drivers/regulator/helpers.c      | 36 +++++++++++++++++++++++++-------
 include/linux/regulator/driver.h |  2 ++
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/drivers/regulator/helpers.c b/drivers/regulator/helpers.c
index f42b394a0c46..3e19ecbf7267 100644
--- a/drivers/regulator/helpers.c
+++ b/drivers/regulator/helpers.c
@@ -508,6 +508,33 @@ int regulator_map_voltage_pickable_linear_range(struct regulator_dev *rdev,
 }
 EXPORT_SYMBOL_GPL(regulator_map_voltage_pickable_linear_range);
 
+/**
+ * regulator_desc_list_voltage_linear - List voltages with simple calculation
+ *
+ * @desc: Regulator desc for regulator which volatges are to be listed
+ * @selector: Selector to convert into a voltage
+ *
+ * Regulators with a simple linear mapping between voltages and
+ * selectors can set min_uV and uV_step in the regulator descriptor
+ * and then use this function prior regulator registration to list
+ * the voltages. This is useful when voltages need to be listed during
+ * device-tree parsing.
+ */
+int regulator_desc_list_voltage_linear(const struct regulator_desc *desc,
+				       unsigned int selector)
+{
+	if (selector >= desc->n_voltages)
+		return -EINVAL;
+
+	if (selector < desc->linear_min_sel)
+		return 0;
+
+	selector -= desc->linear_min_sel;
+
+	return desc->min_uV + (desc->uV_step * selector);
+}
+EXPORT_SYMBOL_GPL(regulator_desc_list_voltage_linear);
+
 /**
  * regulator_list_voltage_linear - List voltages with simple calculation
  *
@@ -521,14 +548,7 @@ EXPORT_SYMBOL_GPL(regulator_map_voltage_pickable_linear_range);
 int regulator_list_voltage_linear(struct regulator_dev *rdev,
 				  unsigned int selector)
 {
-	if (selector >= rdev->desc->n_voltages)
-		return -EINVAL;
-	if (selector < rdev->desc->linear_min_sel)
-		return 0;
-
-	selector -= rdev->desc->linear_min_sel;
-
-	return rdev->desc->min_uV + (rdev->desc->uV_step * selector);
+	return regulator_desc_list_voltage_linear(rdev->desc, selector);
 }
 EXPORT_SYMBOL_GPL(regulator_list_voltage_linear);
 
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index d7c77ee370f3..39a540111645 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -543,4 +543,6 @@ void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data);
 int regulator_desc_list_voltage_linear_range(const struct regulator_desc *desc,
 					     unsigned int selector);
 
+int regulator_desc_list_voltage_linear(const struct regulator_desc *desc,
+				       unsigned int selector);
 #endif
-- 
2.25.4


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]