regmap: Add regmap_get_device

Add a new function regmap_get_device to obtain the underlying struct
device from a regmap.
Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/base/regmap/regmap.c

@@ -1073,6 +1073,18 @@ struct regmap *dev_get_regmap(struct device *dev, const char *name)
 }
 EXPORT_SYMBOL_GPL(dev_get_regmap);
 
+/**
+ * regmap_get_device(): Obtain the device from a regmap
+ *
+ * @map: Register map to operate on.
+ *
+ * Returns the underlying device that the regmap has been created for.
+ */
+struct device *regmap_get_device(struct regmap *map)
+{
+	return map->dev;
+}
+
 static int _regmap_select_page(struct regmap *map, unsigned int *reg,
 			       struct regmap_range_node *range,
 			       unsigned int val_num)

include/linux/regmap.h

@@ -396,6 +396,7 @@ void regmap_exit(struct regmap *map);
 int regmap_reinit_cache(struct regmap *map,
 			const struct regmap_config *config);
 struct regmap *dev_get_regmap(struct device *dev, const char *name);
+struct device *regmap_get_device(struct regmap *map);
 int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
 int regmap_write_async(struct regmap *map, unsigned int reg, unsigned int val);
 int regmap_raw_write(struct regmap *map, unsigned int reg,
@@ -729,6 +730,12 @@ static inline struct regmap *dev_get_regmap(struct device *dev,
 	return NULL;
 }
 
+static inline struct device *regmap_get_device(struct regmap *map)
+{
+	WARN_ONCE(1, "regmap API is disabled");
+	return -EINVAL;
+}
+
 #endif
 
 #endif