Input: ads7846 - add wakeup support

Add wakeup support to the ads7846 driver. Platforms can enable wakeup
capability by setting the wakeup flag in ads7846_platform_data. With this
patch the ads7846 driver can be used to wake the system from suspend.

Signed-off-by: Ranjith Lohithakshan <ranjithl@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index d187be0..532279c 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -822,6 +822,9 @@
 
 	spin_unlock_irq(&ts->lock);
 
+	if (device_may_wakeup(&ts->spi->dev))
+		enable_irq_wake(ts->spi->irq);
+
 	return 0;
 
 }
@@ -830,6 +833,9 @@
 {
 	struct ads7846 *ts = dev_get_drvdata(&spi->dev);
 
+	if (device_may_wakeup(&ts->spi->dev))
+		disable_irq_wake(ts->spi->irq);
+
 	spin_lock_irq(&ts->lock);
 
 	ts->is_suspended = 0;
@@ -1201,6 +1207,8 @@
 	if (err)
 		goto err_remove_attr_group;
 
+	device_init_wakeup(&spi->dev, pdata->wakeup);
+
 	return 0;
 
  err_remove_attr_group:
@@ -1230,6 +1238,8 @@
 {
 	struct ads7846		*ts = dev_get_drvdata(&spi->dev);
 
+	device_init_wakeup(&spi->dev, false);
+
 	ads784x_hwmon_unregister(spi, ts);
 	input_unregister_device(ts->input);