[PATCH 4/6] leds: netdev trigger: simplifications from core changes

[Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>]

The trigger core learned error handling for the activate callback and
to handle device attributes. This allows to simplify the driver
considerably. Note that .deactivate is only called when .new_activate
succeeded, so the check for trigger_data being non-NULL can go away.
(It was broken before because the core didn't clear trigger_data,
so it might have been non-NULL even if .activate failed before.)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
 drivers/leds/trigger/ledtrig-netdev.c | 69 +++++++++------------------
 1 file changed, 22 insertions(+), 47 deletions(-)

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 6df4781a6308..bbdeaa468f9c 100644
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -288,6 +288,16 @@ static ssize_t interval_store(struct device *dev,
 
 static DEVICE_ATTR_RW(interval);
 
+static struct attribute *netdev_trig_attrs[] = {
+	&dev_attr_device_name.attr,
+	&dev_attr_link.attr,
+	&dev_attr_rx.attr,
+	&dev_attr_tx.attr,
+	&dev_attr_interval.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(netdev_trig);
+
 static int netdev_trig_notify(struct notifier_block *nb,
 			      unsigned long evt, void *dv)
 {
@@ -388,14 +398,14 @@ static void netdev_trig_work(struct work_struct *work)
 			(atomic_read(&trigger_data->interval)*2));
 }
 
-static void netdev_trig_activate(struct led_classdev *led_cdev)
+static int netdev_trig_activate(struct led_classdev *led_cdev)
 {
 	struct led_netdev_data *trigger_data;
 	int rc;
 
 	trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 	if (!trigger_data)
-		return;
+		return -ENOMEM;
 
 	spin_lock_init(&trigger_data->lock);
 
@@ -414,67 +424,32 @@ static void netdev_trig_activate(struct led_classdev *led_cdev)
 
 	led_cdev->trigger_data = trigger_data;
 
-	rc = device_create_file(led_cdev->dev, &dev_attr_device_name);
-	if (rc)
-		goto err_out;
-	rc = device_create_file(led_cdev->dev, &dev_attr_link);
-	if (rc)
-		goto err_out_device_name;
-	rc = device_create_file(led_cdev->dev, &dev_attr_rx);
-	if (rc)
-		goto err_out_link;
-	rc = device_create_file(led_cdev->dev, &dev_attr_tx);
-	if (rc)
-		goto err_out_rx;
-	rc = device_create_file(led_cdev->dev, &dev_attr_interval);
-	if (rc)
-		goto err_out_tx;
 	rc = register_netdevice_notifier(&trigger_data->notifier);
 	if (rc)
-		goto err_out_interval;
-	return;
-
-err_out_interval:
-	device_remove_file(led_cdev->dev, &dev_attr_interval);
-err_out_tx:
-	device_remove_file(led_cdev->dev, &dev_attr_tx);
-err_out_rx:
-	device_remove_file(led_cdev->dev, &dev_attr_rx);
-err_out_link:
-	device_remove_file(led_cdev->dev, &dev_attr_link);
-err_out_device_name:
-	device_remove_file(led_cdev->dev, &dev_attr_device_name);
-err_out:
-	led_cdev->trigger_data = NULL;
-	kfree(trigger_data);
+		kfree(trigger_data);
+
+	return rc;
 }
 
 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 {
 	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
 
-	if (trigger_data) {
-		unregister_netdevice_notifier(&trigger_data->notifier);
-
-		device_remove_file(led_cdev->dev, &dev_attr_device_name);
-		device_remove_file(led_cdev->dev, &dev_attr_link);
-		device_remove_file(led_cdev->dev, &dev_attr_rx);
-		device_remove_file(led_cdev->dev, &dev_attr_tx);
-		device_remove_file(led_cdev->dev, &dev_attr_interval);
+	unregister_netdevice_notifier(&trigger_data->notifier);
 
-		cancel_delayed_work_sync(&trigger_data->work);
+	cancel_delayed_work_sync(&trigger_data->work);
 
-		if (trigger_data->net_dev)
-			dev_put(trigger_data->net_dev);
+	if (trigger_data->net_dev)
+		dev_put(trigger_data->net_dev);
 
-		kfree(trigger_data);
-	}
+	kfree(trigger_data);
 }
 
 static struct led_trigger netdev_led_trigger = {
 	.name = "netdev",
-	.activate = netdev_trig_activate,
+	.new_activate = netdev_trig_activate,
 	.deactivate = netdev_trig_deactivate,
+	.groups = netdev_trig_groups,
 };
 
 static int __init netdev_trig_init(void)
-- 
2.17.0