HID: hyperv: register as a wakeup source

With this patch, we can move the mouse to wake up the VM after the VM executes
"echo freeze > /sys/power/state".

This addresses part of https://bugzilla.redhat.com/show_bug.cgi?id=1086100

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-hyperv.c

@@ -308,6 +308,9 @@ static void mousevsc_on_receive(struct hv_device *device,
 		memcpy(input_dev->input_buf, input_report->buffer, len);
 		hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
 				 input_dev->input_buf, len, 1);
+
+		pm_wakeup_event(&input_dev->device->device, 0);
+
 		break;
 	default:
 		pr_err("unsupported hid msg type - type %d len %d",
@@ -549,6 +552,8 @@ static int mousevsc_probe(struct hv_device *device,
 		goto probe_err2;
 	}
 
+	device_init_wakeup(&device->device, true);
+
 	input_dev->connected = true;
 	input_dev->init_complete = true;
 
@@ -571,6 +576,7 @@ static int mousevsc_remove(struct hv_device *dev)
 {
 	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
 
+	device_init_wakeup(&dev->device, false);
 	vmbus_close(dev->channel);
 	hid_hw_stop(input_dev->hid_device);
 	hid_destroy_device(input_dev->hid_device);