power: regulator: Add helper to set voltage within an acceptable range

Add regulator_set_value_clamp() that clamps a requested target voltage
to both caller-provided limits and the regulator constraints before
setting the regulator voltage value.

Return -EINVAL when the caller limits cannot be satisfied by the
regulator constraints or when the requested range is invalid.

This helper will initially be used to set vqmmc-supply voltage within an
acceptable range according to SD Standards, i.e. 1.70V-1.95V and
2.7V-3.6V.

Signed-off-by: Jonas Karlman <[email protected]>
Signed-off-by: Peng Fan <[email protected]>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/power/regulator.h b/include/power/regulator.h
index 4011fb1d254..b8023721a16 100644
--- a/include/power/regulator.h
+++ b/include/power/regulator.h
@@ -316,6 +316,18 @@ int regulator_set_suspend_value(struct udevice *dev, int uV);
 int regulator_get_suspend_value(struct udevice *dev);
 
 /**
+ * regulator_set_value_clamp: set clamped microvoltage value of a given regulator
+ *
+ * @dev       - pointer to the regulator device
+ * @min_uV    - the minimum output value to set [micro Volts]
+ * @target_uV - the target output value to set [micro Volts]
+ * @max_uV    - the maximum output value to set [micro Volts]
+ * Return:    - 0 on success or -errno val if fails
+ */
+int regulator_set_value_clamp(struct udevice *dev,
+			      int min_uV, int target_uV, int max_uV);
+
+/**
  * regulator_set_value_force: set the microvoltage value of a given regulator
  *			      without any min-,max condition check
  *
@@ -550,6 +562,12 @@ static inline int regulator_get_suspend_value(struct udevice *dev)
 	return -ENOSYS;
 }
 
+static inline int regulator_set_value_clamp(struct udevice *dev,
+					    int min_uV, int target_uV, int max_uV)
+{
+	return -ENOSYS;
+}
+
 static inline int regulator_set_value_force(struct udevice *dev, int uV)
 {
 	return -ENOSYS;