[media] smiapp: Implement support for autosuspend

Delay suspending the device by 1000 ms by default. This is done on
explicit power off through s_power() callback, through releasing the
file descriptor, NVM read or when the probe finishes.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/i2c/smiapp/smiapp-core.c

@@ -1380,17 +1380,22 @@ static int smiapp_power_off(struct device *dev)
 
 static int smiapp_set_power(struct v4l2_subdev *subdev, int on)
 {
-	int rval = 0;
+	int rval;
 
-	if (on) {
-		rval = pm_runtime_get_sync(subdev->dev);
-		if (rval >= 0)
-			return 0;
+	if (!on) {
+		pm_runtime_mark_last_busy(subdev->dev);
+		pm_runtime_put_autosuspend(subdev->dev);
 
-		if (rval != -EBUSY && rval != -EAGAIN)
-			pm_runtime_set_active(subdev->dev);
+		return 0;
 	}
 
+	rval = pm_runtime_get_sync(subdev->dev);
+	if (rval >= 0)
+		return 0;
+
+	if (rval != -EBUSY && rval != -EAGAIN)
+		pm_runtime_set_active(subdev->dev);
+
 	pm_runtime_put(subdev->dev);
 
 	return rval;
@@ -2340,7 +2345,8 @@ smiapp_sysfs_nvm_read(struct device *dev, struct device_attribute *attr,
 			return -ENODEV;
 		}
 
-		pm_runtime_put(&client->dev);
+		pm_runtime_mark_last_busy(&client->dev);
+		pm_runtime_put_autosuspend(&client->dev);
 	}
 	/*
 	 * NVM is still way below a PAGE_SIZE, so we can safely
@@ -2681,7 +2687,8 @@ static int smiapp_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 
 static int smiapp_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
 {
-	pm_runtime_put(sd->dev);
+	pm_runtime_mark_last_busy(sd->dev);
+	pm_runtime_put_autosuspend(sd->dev);
 
 	return 0;
 }
@@ -3093,7 +3100,9 @@ static int smiapp_probe(struct i2c_client *client,
 	if (rval < 0)
 		goto out_media_entity_cleanup;
 
-	pm_runtime_put(&client->dev);
+	pm_runtime_set_autosuspend_delay(&client->dev, 1000);
+	pm_runtime_use_autosuspend(&client->dev);
+	pm_runtime_put_autosuspend(&client->dev);
 
 	return 0;