dm: core: add functions to get/remap I/O addresses by name

This functions allow us to get and remap I/O addresses by name, which is useful when there are multiple reg addresses indexed by reg-names property.
This is needed in bmips dma/eth patch series, but can also be used on many
other drivers.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/core/read.c

@@ -69,6 +69,26 @@ void *dev_remap_addr_index(struct udevice *dev, int index)
 	return map_physmem(addr, 0, MAP_NOCACHE);
 }
 
+fdt_addr_t dev_read_addr_name(struct udevice *dev, const char *name)
+{
+	int index = dev_read_stringlist_search(dev, "reg-names", name);
+
+	if (index < 0)
+		return FDT_ADDR_T_NONE;
+	else
+		return dev_read_addr_index(dev, index);
+}
+
+void *dev_remap_addr_name(struct udevice *dev, const char *name)
+{
+	fdt_addr_t addr = dev_read_addr_name(dev, name);
+
+	if (addr == FDT_ADDR_T_NONE)
+		return NULL;
+
+	return map_physmem(addr, 0, MAP_NOCACHE);
+}
+
 fdt_addr_t dev_read_addr(struct udevice *dev)
 {
 	return dev_read_addr_index(dev, 0);