Input: wacom - implement suspend and autosuspend

This implements suspend and autosuspend support for wacom devices.
It works by using the usb last busy functionality triggered in the
completion callback.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/tablet/wacom.h

@@ -101,8 +101,11 @@ struct wacom {
 	dma_addr_t data_dma;
 	struct input_dev *dev;
 	struct usb_device *usbdev;
+	struct usb_interface *intf;
 	struct urb *irq;
 	struct wacom_wac * wacom_wac;
+	struct mutex lock;
+	int open:1;
 	char phys[32];
 };
 

drivers/input/tablet/wacom_sys.c

@@ -70,6 +70,7 @@ static void wacom_sys_irq(struct urb *urb)
 		input_sync(get_input_dev(&wcombo));
 
  exit:
+	usb_mark_last_busy(wacom->usbdev);
 	retval = usb_submit_urb (urb, GFP_ATOMIC);
 	if (retval)
 		err ("%s - usb_submit_urb failed with result %d",
@@ -124,10 +125,25 @@ static int wacom_open(struct input_dev *dev)
 {
 	struct wacom *wacom = input_get_drvdata(dev);
 
+	mutex_lock(&wacom->lock);
+
 	wacom->irq->dev = wacom->usbdev;
-	if (usb_submit_urb(wacom->irq, GFP_KERNEL))
+
+	if (usb_autopm_get_interface(wacom->intf) < 0) {
+		mutex_unlock(&wacom->lock);
 		return -EIO;
+	}
+
+	if (usb_submit_urb(wacom->irq, GFP_KERNEL)) {
+		usb_autopm_put_interface(wacom->intf);
+		mutex_unlock(&wacom->lock);
+		return -EIO;
+	}
+
+	wacom->open = 1;
+	wacom->intf->needs_remote_wakeup = 1;
 
+	mutex_unlock(&wacom->lock);
 	return 0;
 }
 
@@ -135,7 +151,11 @@ static void wacom_close(struct input_dev *dev)
 {
 	struct wacom *wacom = input_get_drvdata(dev);
 
+	mutex_lock(&wacom->lock);
 	usb_kill_urb(wacom->irq);
+	wacom->open = 0;
+	wacom->intf->needs_remote_wakeup = 0;
+	mutex_unlock(&wacom->lock);
 }
 
 void input_dev_mo(struct input_dev *input_dev, struct wacom_wac *wacom_wac)
@@ -243,6 +263,8 @@ static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *i
 
 	wacom->usbdev = dev;
 	wacom->dev = input_dev;
+	wacom->intf = intf;
+	mutex_init(&wacom->lock);
 	usb_make_path(dev, wacom->phys, sizeof(wacom->phys));
 	strlcat(wacom->phys, "/input0", sizeof(wacom->phys));
 
@@ -304,23 +326,57 @@ static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *i
 
 static void wacom_disconnect(struct usb_interface *intf)
 {
-	struct wacom *wacom = usb_get_intfdata (intf);
+	struct wacom *wacom = usb_get_intfdata(intf);
 
 	usb_set_intfdata(intf, NULL);
-	if (wacom) {
-		usb_kill_urb(wacom->irq);
-		input_unregister_device(wacom->dev);
-		usb_free_urb(wacom->irq);
-		usb_buffer_free(interface_to_usbdev(intf), 10, wacom->wacom_wac->data, wacom->data_dma);
-		kfree(wacom->wacom_wac);
-		kfree(wacom);
-	}
+
+	usb_kill_urb(wacom->irq);
+	input_unregister_device(wacom->dev);
+	usb_free_urb(wacom->irq);
+	usb_buffer_free(interface_to_usbdev(intf), 10, wacom->wacom_wac->data, wacom->data_dma);
+	kfree(wacom->wacom_wac);
+	kfree(wacom);
+}
+
+static int wacom_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct wacom *wacom = usb_get_intfdata(intf);
+
+	mutex_lock(&wacom->lock);
+	usb_kill_urb(wacom->irq);
+	mutex_unlock(&wacom->lock);
+
+	return 0;
+}
+
+static int wacom_resume(struct usb_interface *intf)
+{
+	struct wacom *wacom = usb_get_intfdata(intf);
+	int rv;
+
+	mutex_lock(&wacom->lock);
+	if (wacom->open)
+		rv = usb_submit_urb(wacom->irq, GFP_NOIO);
+	else
+		rv = 0;
+	mutex_unlock(&wacom->lock);
+
+	return rv;
+}
+
+static int wacom_reset_resume(struct usb_interface *intf)
+{
+	return wacom_resume(intf);
 }
 
 static struct usb_driver wacom_driver = {
 	.name =		"wacom",
 	.probe =	wacom_probe,
 	.disconnect =	wacom_disconnect,
+	.suspend =	wacom_suspend,
+	.resume =	wacom_resume,
+	.reset_resume =	wacom_reset_resume,
+	.supports_autosuspend = 1,
 };
 
 static int __init wacom_init(void)