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path: root/drivers/usb/core/of.c
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Diffstat (limited to 'drivers/usb/core/of.c')
-rw-r--r--drivers/usb/core/of.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/usb/core/of.c b/drivers/usb/core/of.c
new file mode 100644
index 000000000000..2289700c31d6
--- /dev/null
+++ b/drivers/usb/core/of.c
@@ -0,0 +1,47 @@
+/*
+ * of.c The helpers for hcd device tree support
+ *
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Author: Peter Chen <peter.chen@freescale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/of.h>
+
+/**
+ * usb_of_get_child_node - Find the device node match port number
+ * @parent: the parent device node
+ * @portnum: the port number which device is connecting
+ *
+ * Find the node from device tree according to its port number.
+ *
+ * Return: On success, a pointer to the device node, %NULL on failure.
+ */
+struct device_node *usb_of_get_child_node(struct device_node *parent,
+ int portnum)
+{
+ struct device_node *node;
+ u32 port;
+
+ for_each_child_of_node(parent, node) {
+ if (!of_property_read_u32(node, "reg", &port)) {
+ if (port == portnum)
+ return node;
+ }
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(usb_of_get_child_node);
+