[PATCH 4.9 102/120] regulators: helpers: Fix handling of bypass_val_on in get_bypass_regmap

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>

commit 85b037442e3f0e84296ab1010fd6b057eee18496 upstream.

The handling of bypass_val_on that was added in
regulator_get_bypass_regmap is done unconditionally however
several drivers don't define a value for bypass_val_on. This
results in those drivers reporting bypass being enabled when
it is not. In regulator_set_bypass_regmap we use bypass_mask
if bypass_val_on is zero. This patch adds similar handling in
regulator_get_bypass_regmap.

Fixes: commit dd1a571daee7 ("regulator: helpers: Ensure bypass register field matches ON value")
Signed-off-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/regulator/helpers.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/regulator/helpers.c
+++ b/drivers/regulator/helpers.c
@@ -454,13 +454,17 @@ EXPORT_SYMBOL_GPL(regulator_set_bypass_r
 int regulator_get_bypass_regmap(struct regulator_dev *rdev, bool *enable)
 {
 	unsigned int val;
+	unsigned int val_on = rdev->desc->bypass_val_on;
 	int ret;
 
 	ret = regmap_read(rdev->regmap, rdev->desc->bypass_reg, &val);
 	if (ret != 0)
 		return ret;
 
-	*enable = (val & rdev->desc->bypass_mask) == rdev->desc->bypass_val_on;
+	if (!val_on)
+		val_on = rdev->desc->bypass_mask;
+
+	*enable = (val & rdev->desc->bypass_mask) == val_on;
 
 	return 0;
 }