diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index ca465794ea9c..c6f139b2e0c0 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -255,6 +255,24 @@ struct regmap *syscon_regmap_lookup_by_phandle_args(struct device_node *np, } EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_args); +/* + * It behaves the same as syscon_regmap_lookup_by_phandle() except where + * there is no regmap phandle. In this case, instead of returning -ENODEV, + * the function returns NULL. + */ +struct regmap *syscon_regmap_lookup_by_phandle_optional(struct device_node *np, + const char *property) +{ + struct regmap *regmap; + + regmap = syscon_regmap_lookup_by_phandle(np, property); + if (IS_ERR(regmap) && PTR_ERR(regmap) == -ENODEV) + return NULL; + + return regmap; +} +EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_phandle_optional); + static int syscon_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h index 7f20e9b502a5..fecc2fa2a364 100644 --- a/include/linux/mfd/syscon.h +++ b/include/linux/mfd/syscon.h @@ -28,6 +28,9 @@ extern struct regmap *syscon_regmap_lookup_by_phandle_args( const char *property, int arg_count, unsigned int *out_args); +extern struct regmap *syscon_regmap_lookup_by_phandle_optional( + struct device_node *np, + const char *property); #else static inline struct regmap *device_node_to_regmap(struct device_node *np) { @@ -59,6 +62,14 @@ static inline struct regmap *syscon_regmap_lookup_by_phandle_args( { return ERR_PTR(-ENOTSUPP); } + +static inline struct regmap *syscon_regmap_lookup_by_phandle_optional( + struct device_node *np, + const char *property) +{ + return NULL; +} + #endif #endif /* __LINUX_MFD_SYSCON_H__ */