Input: usbtouchscreen - implement runtime power management

This implement USB autosuspend while the device is opened for
devices that do remote wakeup with a fallback to open/close for
those devices that don't. Devices that require the host to
constantly poll them are never autosuspended.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Tested-by: Petr Štetiar <ynezz@true.cz>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c
index 9cda660..77e671f 100644 (file)
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c
@@ -1268,6 +1268,7 @@ static void usbtouch_irq(struct urb *urb)
        usbtouch->type->process_pkt(usbtouch, usbtouch->data, urb->actual_length);
 
 exit:
+       usb_mark_last_busy(interface_to_usbdev(usbtouch->interface));
        retval = usb_submit_urb(urb, GFP_ATOMIC);
        if (retval)
                err("%s - usb_submit_urb failed with result: %d",
@@ -1277,23 +1278,39 @@ exit:
 static int usbtouch_open(struct input_dev *input)
 {
        struct usbtouch_usb *usbtouch = input_get_drvdata(input);
+       int r;
 
        usbtouch->irq->dev = interface_to_usbdev(usbtouch->interface);
 
+       r = usb_autopm_get_interface(usbtouch->interface) ? -EIO : 0;
+       if (r < 0)
+               goto out;
+
        if (!usbtouch->type->irq_always) {
-               if (usb_submit_urb(usbtouch->irq, GFP_KERNEL))
-                 return -EIO;
+               if (usb_submit_urb(usbtouch->irq, GFP_KERNEL)) {
+                       r = -EIO;
+                       goto out_put;
+               }
        }
 
-       return 0;
+       usbtouch->interface->needs_remote_wakeup = 1;
+out_put:
+       usb_autopm_put_interface(usbtouch->interface);
+out:
+       return r;
 }
 
 static void usbtouch_close(struct input_dev *input)
 {
        struct usbtouch_usb *usbtouch = input_get_drvdata(input);
+       int r;
 
        if (!usbtouch->type->irq_always)
                usb_kill_urb(usbtouch->irq);
+       r = usb_autopm_get_interface(usbtouch->interface);
+       usbtouch->interface->needs_remote_wakeup = 0;
+       if (!r)
+               usb_autopm_put_interface(usbtouch->interface);
 }
 
 static int usbtouch_suspend
@@ -1457,8 +1474,11 @@ static int usbtouch_probe(struct usb_interface *intf,
        usb_set_intfdata(intf, usbtouch);
 
        if (usbtouch->type->irq_always) {
+               /* this can't fail */
+               usb_autopm_get_interface(intf);
                err = usb_submit_urb(usbtouch->irq, GFP_KERNEL);
                if (err) {
+                       usb_autopm_put_interface(intf);
                        err("%s - usb_submit_urb failed with result: %d",
                            __func__, err);
                        goto out_unregister_input;
@@ -1512,6 +1532,7 @@ static struct usb_driver usbtouch_driver = {
        .suspend        = usbtouch_suspend,
        .resume         = usbtouch_resume,
        .id_table       = usbtouch_devices,
+       .supports_autosuspend = 1,
 };
 
 static int __init usbtouch_init(void)