[PATCH RFC 1/2] regulator: core: Allow uV_step to be 0 for linear mapping if fixed voltage

[Axel Lin <axel.lin@gmail.com>]

Fixed voltage is a kind of linear mapping where n_voltages is 1 and uV_step is
0. This change allows [list|map]_voltage_linear to be used for fixed voltage.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/regulator/core.c |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 02c1940..876f5fc 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2070,6 +2070,14 @@ int regulator_map_voltage_linear(struct regulator_dev *rdev,
 {
 	int ret, voltage;
 
+	/* Allow uV_step to be 0 for fixed voltage */
+	if (rdev->desc->n_voltages == 1 && rdev->desc->uV_step == 0) {
+		if (min_uV <= rdev->desc->min_uV && rdev->desc->min_uV <= max_uV)
+			return 0;
+		else
+			return -EINVAL;
+	}
+
 	if (!rdev->desc->uV_step) {
 		BUG_ON(!rdev->desc->uV_step);
 		return -EINVAL;
-- 
1.7.9.5