linux-kernel - [PATCH v1 07/12] usb: roles: Find the usb role switch by also matching against the device node

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Message-ID: <20181203034515.91412-8-chenyu56@huawei.com>
Date:   Mon, 3 Dec 2018 11:45:10 +0800
From:   Yu Chen <chenyu56@...wei.com>
To:     <linux-usb@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>
CC:     <suzhuangluan@...ilicon.com>, <kongfei@...ilicon.com>,
        Yu Chen <chenyu56@...wei.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Andy Shevchenko <andy.shevchenko@...il.com>,
        "John Stultz" <john.stultz@...aro.org>
Subject: [PATCH v1 07/12] usb: roles: Find the usb role switch by also matching against the device node

This patch adds code for supporting find usb role switch by matching against
the device node described using of_graph.

Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Cc: Hans de Goede <hdegoede@...hat.com>
Cc: Andy Shevchenko <andy.shevchenko@...il.com>
Cc: John Stultz <john.stultz@...aro.org>
Signed-off-by: Yu Chen <chenyu56@...wei.com>
---
 drivers/usb/common/roles.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/usb/common/roles.c b/drivers/usb/common/roles.c
index 99116af07f1d..0f48090c5c30 100644
--- a/drivers/usb/common/roles.c
+++ b/drivers/usb/common/roles.c
@@ -12,6 +12,8 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
 
 static struct class *role_class;
 
@@ -100,6 +102,38 @@ static void *usb_role_switch_match(struct device_connection *con, int ep,
 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);
 }
 
+static int __switch_match_by_of_node(struct device *dev, const void *name)
+{
+	if (!dev->parent || !dev->parent->of_node)
+		return 0;
+
+	return of_node_name_eq(dev->parent->of_node, (const char *)name);
+}
+
+static void *of_graph_find_match_by_type(struct device *dev, const char *ep_type)
+{
+	struct device_node *ep;
+	struct device_node *remote_parent;
+	struct device *role_switch;
+
+	for_each_endpoint_of_node(dev_of_node(dev), ep) {
+		if (!ep->type || strcmp(ep->type, ep_type))
+			continue;
+
+		remote_parent = of_graph_get_remote_port_parent(ep);
+		if (!remote_parent || !remote_parent->name)
+			continue;
+
+		role_switch = class_find_device(role_class, NULL,
+				remote_parent->name, __switch_match_by_of_node);
+
+		return role_switch ? to_role_switch(role_switch) :
+			ERR_PTR(-EPROBE_DEFER);
+	}
+
+	return NULL;
+}
+
 /**
  * usb_role_switch_get - Find USB role switch linked with the caller
  * @dev: The caller device
@@ -114,6 +148,12 @@ struct usb_role_switch *usb_role_switch_get(struct device *dev)
 	sw = device_connection_find_match(dev, "usb-role-switch", NULL,
 					  usb_role_switch_match);
 
+	if (!IS_ERR_OR_NULL(sw)) {
+		WARN_ON(!try_module_get(sw->dev.parent->driver->owner));
+		return sw;
+	}
+
+	sw = of_graph_find_match_by_type(dev, "usb-role-switch");
 	if (!IS_ERR_OR_NULL(sw))
 		WARN_ON(!try_module_get(sw->dev.parent->driver->owner));
 
-- 
2.15.0-rc2