regulator: core: Return error in get optional stub

Drivers that call regulator_get_optional are tolerant to the absence of
that regulator.  By modifying the value returned from the stub function
to match that seen when a regulator isn't present, callers can wrap the
regulator logic with an IS_ERR based conditional even if they happen to
call regulator_is_supported_voltage.  This improves efficiency as well
as eliminates the possibility for a very subtle bug.

Signed-off-by: Tim Kryger <tim.kryger@linaro.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index e530681bea7049cfa818e66acea0bf863952d281..1a4a8c157b31a7eb8cf3e9c1bedba8ab64354542 100644 (file)
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -258,14 +258,14 @@ regulator_get_exclusive(struct device *dev, const char *id)
 static inline struct regulator *__must_check
 regulator_get_optional(struct device *dev, const char *id)
 {
-       return NULL;
+       return ERR_PTR(-ENODEV);
 }
 
 
 static inline struct regulator *__must_check
 devm_regulator_get_optional(struct device *dev, const char *id)
 {
-       return NULL;
+       return ERR_PTR(-ENODEV);
 }
 
 static inline void regulator_put(struct regulator *regulator)