usb: roles: Add usb_role_switch_find_by_fwnode()

Simple wrapper function that searches USB role switches with
class_find_device_by_fwnode().

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20191008122600.22340-2-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/roles/class.c b/drivers/usb/roles/class.c
index 94b4e7d..8273126 100644 (file)
--- a/drivers/usb/roles/class.c
+++ b/drivers/usb/roles/class.c
@@ -175,6 +175,27 @@ void usb_role_switch_put(struct usb_role_switch *sw)
 }
 EXPORT_SYMBOL_GPL(usb_role_switch_put);
 
+/**
+ * usb_role_switch_find_by_fwnode - Find USB role switch with its fwnode
+ * @fwnode: fwnode of the USB Role Switch
+ *
+ * Finds and returns role switch with @fwnode. The reference count for the
+ * found switch is incremented.
+ */
+struct usb_role_switch *
+usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode)
+{
+       struct device *dev;
+
+       if (!fwnode)
+               return NULL;
+
+       dev = class_find_device_by_fwnode(role_class, fwnode);
+
+       return dev ? to_role_switch(dev) : NULL;
+}
+EXPORT_SYMBOL_GPL(usb_role_switch_find_by_fwnode);
+
 static umode_t
 usb_role_switch_is_visible(struct kobject *kobj, struct attribute *attr, int n)
 {

diff --git a/include/linux/usb/role.h b/include/linux/usb/role.h
index 2d77f97..efac3af 100644 (file)
--- a/include/linux/usb/role.h
+++ b/include/linux/usb/role.h
@@ -51,6 +51,9 @@ struct usb_role_switch *fwnode_usb_role_switch_get(struct fwnode_handle *node);
 void usb_role_switch_put(struct usb_role_switch *sw);
 
 struct usb_role_switch *
+usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode);
+
+struct usb_role_switch *
 usb_role_switch_register(struct device *parent,
                         const struct usb_role_switch_desc *desc);
 void usb_role_switch_unregister(struct usb_role_switch *sw);