[PATCH] regulator: core: Use parent voltage from the supply when bypassed

[Mark Brown <broonie@kernel.org>]

When a regulator is in bypass mode it is functioning as a switch
returning the voltage set in the regulator will not give the voltage
being output by the regulator as it's just passing through its supply.
This means that when we are getting the voltage from a regulator we
should check to see if it is in bypass mode and if it is we should
report the voltage from the supply rather than that which is set on the
regulator.

Reported-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---

Completely untested.

 drivers/regulator/core.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 74e8a7a3b3e8..03042e450399 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -3118,6 +3118,20 @@ EXPORT_SYMBOL_GPL(regulator_sync_voltage);
 static int _regulator_get_voltage(struct regulator_dev *rdev)
 {
 	int sel, ret;
+	bool bypassed;
+
+	if (rdev->desc->ops->get_bypass) {
+		ret = rdev->desc->ops->get_bypass(rdev, &bypassed);
+		if (ret < 0)
+			return ret;
+		if (bypassed) {
+			if (rdev->supply) {
+				ret = _regulator_get_voltage(rdev->supply->rdev);
+			} else {
+				return -EINVAL;
+			}
+		}
+	}
 
 	if (rdev->desc->ops->get_voltage_sel) {
 		sel = rdev->desc->ops->get_voltage_sel(rdev);
-- 
2.8.0.rc3