regulator: Fix _regulator_get_voltage if get_voltage callback is NULL

In the case of get_voltage callback is NULL, current implementation in
_regulator_get_voltage will return -EINVAL.

Also returns proper error if ret is negative value.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

1 files changed, 5 insertions, 3 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 9493f6111a38..d3e38790906e 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1886,12 +1886,14 @@ static int _regulator_get_voltage(struct regulator_dev *rdev)
                 if (sel < 0)
                         return sel;
                 ret = rdev->desc->ops->list_voltage(rdev, sel);
-        }
-        if (rdev->desc->ops->get_voltage)
+        } else if (rdev->desc->ops->get_voltage) {
                 ret = rdev->desc->ops->get_voltage(rdev);
-        else
+        } else {
                 return -EINVAL;
+        }
 
+        if (ret < 0)
+                return ret;
         return ret - rdev->constraints->uV_offset;
 }