usb: Register usb port's acpi power resources

This patch is to register usb port's acpi power resources. Create
link between usb port device and its acpi power resource.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/port.c

@@ -66,6 +66,7 @@ static void usb_port_device_release(struct device *dev)
 {
 	struct usb_port *port_dev = to_usb_port(dev);
 
+	usb_acpi_unregister_power_resources(dev);
 	kfree(port_dev);
 }
 
@@ -95,6 +96,10 @@ int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 	if (retval)
 		goto error_register;
 
+	retval = usb_acpi_register_power_resources(&port_dev->dev);
+	if (retval && retval != -ENODEV)
+		dev_warn(&port_dev->dev, "the port can't register its ACPI power resource.\n");
+
 	return 0;
 
 error_register:

drivers/usb/core/usb-acpi.c

@@ -216,6 +216,24 @@ static struct acpi_bus_type usb_acpi_bus = {
 	.find_device = usb_acpi_find_device,
 };
 
+int usb_acpi_register_power_resources(struct device *dev)
+{
+	acpi_handle port_handle = DEVICE_ACPI_HANDLE(dev);
+
+	if (!port_handle)
+		return -ENODEV;
+
+	return acpi_power_resource_register_device(dev, port_handle);
+}
+
+void usb_acpi_unregister_power_resources(struct device *dev)
+{
+	acpi_handle port_handle = DEVICE_ACPI_HANDLE(dev);
+
+	if (port_handle)
+		acpi_power_resource_unregister_device(dev, port_handle);
+}
+
 int usb_acpi_register(void)
 {
 	return register_acpi_bus_type(&usb_acpi_bus);

drivers/usb/core/usb.h

@@ -191,7 +191,13 @@ extern int usb_acpi_register(void);
 extern void usb_acpi_unregister(void);
 extern acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
 	int port1);
+extern int usb_acpi_register_power_resources(struct device *dev);
+extern void usb_acpi_unregister_power_resources(struct device *dev);
 #else
 static inline int usb_acpi_register(void) { return 0; };
 static inline void usb_acpi_unregister(void) { };
+static inline int usb_acpi_register_power_resources(struct device *dev)
+	{ return 0; };
+static inline void usb_acpi_unregister_power_resources(struct device *dev)
+	{ };
 #endif