fdt: implement dev_get_addr_name()

This function parses the reg property based on an index found in the
reg-names property. This is required for bindings that are written
using reg-names rather than hard-coding indices in reg.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Acked-by: NSimon Glass <sjg@chromium.org>

drivers/core/device.c

@@ -652,6 +652,22 @@ fdt_addr_t dev_get_addr_index(struct udevice *dev, int index)
 #endif
 }
 
+fdt_addr_t dev_get_addr_name(struct udevice *dev, const char *name)
+{
+#if CONFIG_IS_ENABLED(OF_CONTROL)
+	int index;
+
+	index = fdt_find_string(gd->fdt_blob, dev->parent->of_offset,
+				"reg-names", name);
+	if (index < 0)
+		return index;
+
+	return dev_get_addr_index(dev, index);
+#else
+	return FDT_ADDR_T_NONE;
+#endif
+}
+
 fdt_addr_t dev_get_addr(struct udevice *dev)
 {
 	return dev_get_addr_index(dev, 0);

include/dm/device.h

@@ -464,6 +464,18 @@ fdt_addr_t dev_get_addr(struct udevice *dev);
  */
 fdt_addr_t dev_get_addr_index(struct udevice *dev, int index);
 
+/**
+ * dev_get_addr_name() - Get the reg property of a device, indexed by name
+ *
+ * @dev: Pointer to a device
+ * @name: the 'reg' property can hold a list of <addr, size> pairs, with the
+ *	  'reg-names' property providing named-based identification. @index
+ *	  indicates the value to search for in 'reg-names'.
+ *
+ * @return addr
+ */
+fdt_addr_t dev_get_addr_name(struct udevice *dev, const char *name);
+
 /**
  * device_has_children() - check if a device has any children
  *