[PATCH RFC RESEND 1/3] regulator: core: Handle fixed voltage in map_voltage_linear

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

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

For fixed voltage, n_voltages is 1 and the only valid selector is 0.
Thus we actually don't care the uV_step setting.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
This patch is v2 of 
[PATCH RFC 1/2] regulator: core: Allow uV_step to be 0 for linear mapping if fixed voltage.

I change the subject line because for fixed voltage, we actually don't care the uV_step setting.

 drivers/regulator/core.c |    9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 02c1940..45baa72 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2070,6 +2070,15 @@ int regulator_map_voltage_linear(struct regulator_dev *rdev,
 {
 	int ret, voltage;
 
+	/* For fixed voltage, check if voltage falls within specified range */
+	if (rdev->desc->n_voltages == 1) {
+		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