Input: ad7879 - consolidate PM methods

The PM methods are basically the same for SPI and I2C busses, so let's
use the same dev_pm_ops for both of them.

Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
index 76f5cb4..dce60b8 100644
--- a/drivers/input/touchscreen/ad7879.c
+++ b/drivers/input/touchscreen/ad7879.c
@@ -280,8 +280,11 @@
 		__ad7879_disable(ts);
 }
 
-void ad7879_suspend(struct ad7879 *ts)
+#ifdef CONFIG_PM_SLEEP
+static int ad7879_suspend(struct device *dev)
 {
+	struct ad7879 *ts = dev_get_drvdata(dev);
+
 	mutex_lock(&ts->input->mutex);
 
 	if (!ts->suspended && !ts->disabled && ts->input->users)
@@ -290,11 +293,14 @@
 	ts->suspended = true;
 
 	mutex_unlock(&ts->input->mutex);
-}
-EXPORT_SYMBOL(ad7879_suspend);
 
-void ad7879_resume(struct ad7879 *ts)
+	return 0;
+}
+
+static int ad7879_resume(struct device *dev)
 {
+	struct ad7879 *ts = dev_get_drvdata(dev);
+
 	mutex_lock(&ts->input->mutex);
 
 	if (ts->suspended && !ts->disabled && ts->input->users)
@@ -303,8 +309,13 @@
 	ts->suspended = false;
 
 	mutex_unlock(&ts->input->mutex);
+
+	return 0;
 }
-EXPORT_SYMBOL(ad7879_resume);
+#endif
+
+SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
+EXPORT_SYMBOL(ad7879_pm_ops);
 
 static void ad7879_toggle(struct ad7879 *ts, bool disable)
 {