linux-kernel - [PATCH 1/2] of: property: Get rid of code duplication in port getting

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Date:   Thu, 10 Dec 2020 22:29:44 +0200
From:   Sam Protsenko <semen.protsenko@...aro.org>
To:     devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Rob Herring <robh+dt@...nel.org>,
        Frank Rowand <frowand.list@...il.com>,
        John Stultz <john.stultz@...aro.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Sam Ravnborg <sam@...nborg.org>,
        Dmitry Osipenko <digetx@...il.com>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>
Subject: [PATCH 1/2] of: property: Get rid of code duplication in port getting

Both of_graph_is_present() and of_graph_get_next_endpoint() functions
share common piece of code for obtaining the graph port. Extract it into
separate static function to get rid of code duplication and avoid
possible coding errors in future.

Fixes: 4ec0a44ba8d7 ("of_graph: add of_graph_is_present()")
Signed-off-by: Sam Protsenko <semen.protsenko@...aro.org>
---
 drivers/of/property.c | 34 ++++++++++++++++++++--------------
 1 file changed, 20 insertions(+), 14 deletions(-)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index 408a7b5f06a9..da111fcf37ac 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -30,13 +30,13 @@
 #include "of_private.h"
 
 /**
- * of_graph_is_present() - check graph's presence
+ * of_graph_get_port - find the "port" node in a given node
  * @node: pointer to device_node containing graph port
  *
- * Return: True if @node has a port or ports (with a port) sub-node,
- * false otherwise.
+ * Return: A 'port' node pointer with refcount incremented if found or NULL
+ * otherwise. The caller has to use of_node_put() on it when done.
  */
-bool of_graph_is_present(const struct device_node *node)
+static struct device_node *of_graph_get_port(const struct device_node *node)
 {
 	struct device_node *ports, *port;
 
@@ -46,8 +46,22 @@ bool of_graph_is_present(const struct device_node *node)
 
 	port = of_get_child_by_name(node, "port");
 	of_node_put(ports);
-	of_node_put(port);
 
+	return port;
+}
+
+/**
+ * of_graph_is_present() - check graph's presence
+ * @node: pointer to device_node containing graph port
+ *
+ * Return: True if @node has a port or ports (with a port) sub-node,
+ * false otherwise.
+ */
+bool of_graph_is_present(const struct device_node *node)
+{
+	struct device_node *port = of_graph_get_port(node);
+
+	of_node_put(port);
 	return !!port;
 }
 EXPORT_SYMBOL(of_graph_is_present);
@@ -631,15 +645,7 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
 	 * parent port node.
 	 */
 	if (!prev) {
-		struct device_node *node;
-
-		node = of_get_child_by_name(parent, "ports");
-		if (node)
-			parent = node;
-
-		port = of_get_child_by_name(parent, "port");
-		of_node_put(node);
-
+		port = of_graph_get_port(parent);
 		if (!port) {
 			pr_err("graph: no port node found in %pOF\n", parent);
 			return NULL;
-- 
2.27.0