[RFC] regulator: core: Support for continuous voltage range

[Pawel Moll <pawel.moll@arm.com>]

Some regulators can set any voltage within the constraints range,
not being limited to specified operating points.

This patch makes it possible to describe such regulator and makes
the regulator_is_supported_voltage() function behave correctly.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
---
 drivers/regulator/core.c         |    5 +++++
 include/linux/regulator/driver.h |    3 +++
 2 files changed, 8 insertions(+)

Hi Mark,

This is roughly what we discussed last week. Alternatively, it could be
also a "universal" unsigned regulator_desc.flags field with #define
REGULATOR_FLAG_CONTINUOUS_VOLTAGE_RAGE 0x1.

Regards

Pawel

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 4838531..808928a 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1947,6 +1947,11 @@ int regulator_is_supported_voltage(struct regulator *regulator,
 			return ret;
 	}
 
+	/* Any voltage within constrains range is fine? */
+	if (rdev->desc->continuous_voltage_range)
+		return min_uV >= rdev->constraints->min_uV &&
+				max_uV <= rdev->constraints->max_uV;
+
 	ret = regulator_count_voltages(regulator);
 	if (ret < 0)
 		return ret;
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index bac4c87..2f915b9 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -171,6 +171,8 @@ enum regulator_type {
  * @type: Indicates if the regulator is a voltage or current regulator.
  * @owner: Module providing the regulator, used for refcounting.
  *
+ * @continuous_voltage_range: Indicates if the regulator can set any
+ *                            voltage within constrains range.
  * @n_voltages: Number of selectors available for ops.list_voltage().
  *
  * @min_uV: Voltage given by the lowest selector (if linear mapping)
@@ -189,6 +191,7 @@ struct regulator_desc {
 	const char *name;
 	const char *supply_name;
 	int id;
+	bool continuous_voltage_range;
 	unsigned n_voltages;
 	struct regulator_ops *ops;
 	int irq;
-- 
1.7.9.5