ofnode: add {ofnode, dev}_read_resource_byname()

Linux supports platform_get_resource_byname() to look up a resource
by name.

We want a similar helper.  It is useful when a device node has named
register regions.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 18 insertions, 0 deletions

diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index c1a2e9f0da..0685b689d8 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -627,3 +627,15 @@ int ofnode_read_resource(ofnode node, uint index, struct resource *res)
 		return 0;
 	}
 }
+
+int ofnode_read_resource_byname(ofnode node, const char *name,
+				struct resource *res)
+{
+	int index;
+
+	index = ofnode_stringlist_search(node, "reg-names", name);
+	if (index < 0)
+		return index;
+
+	return ofnode_read_resource(node, index, res);
+}
diff --git a/drivers/core/read.c b/drivers/core/read.c
index fe40bed64d..6acb33388f 100644
--- a/drivers/core/read.c
+++ b/drivers/core/read.c
@@ -164,3 +164,9 @@ int dev_read_resource(struct udevice *dev, uint index, struct resource *res)
 {
 	return ofnode_read_resource(dev_ofnode(dev), index, res);
 }
+
+int dev_read_resource_byname(struct udevice *dev, const char *name,
+			     struct resource *res)
+{
+	return ofnode_read_resource_byname(dev_ofnode(dev), name, res);
+}