USB: Add new PM callback methods for USB

This patch (as1129) adds support for the new PM callbacks to usbcore.
The new callbacks merely invoke the same old USB power management
routines as the old ones did.

A minor improvement is that the callbacks are present only in the
"USB-device" device_type structure, rather than in the bus_type
structure.  This way they will be invoked only for USB devices, not
for USB interfaces.  The core USB PM routines automatically handle
suspending and resuming interfaces along with their devices.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/driver.c

@@ -1630,12 +1630,10 @@ int usb_external_resume_device(struct usb_device *udev)
 	return status;
 }
 
-static int usb_suspend(struct device *dev, pm_message_t message)
+int usb_suspend(struct device *dev, pm_message_t message)
 {
 	struct usb_device	*udev;
 
-	if (!is_usb_device(dev))	/* Ignore PM for interfaces */
-		return 0;
 	udev = to_usb_device(dev);
 
 	/* If udev is already suspended, we can skip this suspend and
@@ -1654,12 +1652,10 @@ static int usb_suspend(struct device *dev, pm_message_t message)
 	return usb_external_suspend_device(udev, message);
 }
 
-static int usb_resume(struct device *dev)
+int usb_resume(struct device *dev)
 {
 	struct usb_device	*udev;
 
-	if (!is_usb_device(dev))	/* Ignore PM for interfaces */
-		return 0;
 	udev = to_usb_device(dev);
 
 	/* If udev->skip_sys_resume is set then udev was already suspended
@@ -1671,17 +1667,10 @@ static int usb_resume(struct device *dev)
 	return usb_external_resume_device(udev);
 }
 
-#else
-
-#define usb_suspend	NULL
-#define usb_resume	NULL
-
 #endif /* CONFIG_PM */
 
 struct bus_type usb_bus_type = {
 	.name =		"usb",
 	.match =	usb_device_match,
 	.uevent =	usb_uevent,
-	.suspend =	usb_suspend,
-	.resume =	usb_resume,
 };

drivers/usb/core/usb.c

@@ -219,12 +219,6 @@ static int usb_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 }
 #endif	/* CONFIG_HOTPLUG */
 
-struct device_type usb_device_type = {
-	.name =		"usb_device",
-	.release =	usb_release_dev,
-	.uevent =	usb_dev_uevent,
-};
-
 #ifdef	CONFIG_PM
 
 static int ksuspend_usb_init(void)
@@ -244,13 +238,80 @@ static void ksuspend_usb_cleanup(void)
 	destroy_workqueue(ksuspend_usb_wq);
 }
 
+/* USB device Power-Management thunks.
+ * There's no need to distinguish here between quiescing a USB device
+ * and powering it down; the generic_suspend() routine takes care of
+ * it by skipping the usb_port_suspend() call for a quiesce.  And for
+ * USB interfaces there's no difference at all.
+ */
+
+static int usb_dev_prepare(struct device *dev)
+{
+	return 0;		/* Implement eventually? */
+}
+
+static void usb_dev_complete(struct device *dev)
+{
+	/* Currently used only for rebinding interfaces */
+	usb_resume(dev);	/* Implement eventually? */
+}
+
+static int usb_dev_suspend(struct device *dev)
+{
+	return usb_suspend(dev, PMSG_SUSPEND);
+}
+
+static int usb_dev_resume(struct device *dev)
+{
+	return usb_resume(dev);
+}
+
+static int usb_dev_freeze(struct device *dev)
+{
+	return usb_suspend(dev, PMSG_FREEZE);
+}
+
+static int usb_dev_thaw(struct device *dev)
+{
+	return usb_resume(dev);
+}
+
+static int usb_dev_poweroff(struct device *dev)
+{
+	return usb_suspend(dev, PMSG_HIBERNATE);
+}
+
+static int usb_dev_restore(struct device *dev)
+{
+	return usb_resume(dev);
+}
+
+static struct pm_ops usb_device_pm_ops = {
+	.prepare =	usb_dev_prepare,
+	.complete =	usb_dev_complete,
+	.suspend =	usb_dev_suspend,
+	.resume =	usb_dev_resume,
+	.freeze =	usb_dev_freeze,
+	.thaw =		usb_dev_thaw,
+	.poweroff =	usb_dev_poweroff,
+	.restore =	usb_dev_restore,
+};
+
 #else
 
 #define ksuspend_usb_init()	0
 #define ksuspend_usb_cleanup()	do {} while (0)
+#define usb_device_pm_ops	(*(struct pm_ops *)0)
 
 #endif	/* CONFIG_PM */
 
+struct device_type usb_device_type = {
+	.name =		"usb_device",
+	.release =	usb_release_dev,
+	.uevent =	usb_dev_uevent,
+	.pm =		&usb_device_pm_ops,
+};
+
 
 /* Returns 1 if @usb_bus is WUSB, 0 otherwise */
 static unsigned usb_bus_is_wusb(struct usb_bus *bus)

drivers/usb/core/usb.h

@@ -41,6 +41,9 @@ extern void usb_host_cleanup(void);
 
 #ifdef	CONFIG_PM
 
+extern int usb_suspend(struct device *dev, pm_message_t msg);
+extern int usb_resume(struct device *dev);
+
 extern void usb_autosuspend_work(struct work_struct *work);
 extern int usb_port_suspend(struct usb_device *dev);
 extern int usb_port_resume(struct usb_device *dev);