regmap: Add devm_regmap_init()

Most of new linux drivers are using managed-API to allocate resources. To
ease porting drivers from linux to U-Boot, introduce devm_regmap_init() as
a managed API to get a regmap from the device tree.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
diff --git a/include/regmap.h b/include/regmap.h
index 30183c5..c7dd240 100644
--- a/include/regmap.h
+++ b/include/regmap.h
@@ -75,6 +75,9 @@
 	ulong size;
 };
 
+struct regmap_bus;
+struct regmap_config;
+
 /**
  * struct regmap - a way of accessing hardware/bus registers
  *
@@ -336,6 +339,21 @@
 int regmap_init_mem_index(ofnode node, struct regmap **mapp, int index);
 
 /**
+ * devm_regmap_init() - Initialise register map (device managed)
+ *
+ * @dev: Device that will be interacted with
+ * @bus: Bus-specific callbacks to use with device (IGNORED)
+ * @bus_context: Data passed to bus-specific callbacks (IGNORED)
+ * @config: Configuration for register map (IGNORED)
+ *
+ * @Return a valid pointer to a struct regmap or a ERR_PTR() on error.
+ * The structure is automatically freed when the device is unbound
+ */
+struct regmap *devm_regmap_init(struct udevice *dev,
+				const struct regmap_bus *bus,
+				void *bus_context,
+				const struct regmap_config *config);
+/**
  * regmap_get_range() - Obtain the base memory address of a regmap range
  *
  * @map:	Regmap to query