leds: netdev trigger: simplifications from core changes

The trigger core learned error handling for the activate callback and
can handle device attributes now. This allows simplifying the driver
considerably. Note that .deactivate() is only called when .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@pengutronix.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

drivers/leds/trigger/ledtrig-netdev.c

@@ -94,8 +94,7 @@ static void set_baseline_state(struct led_netdev_data *trigger_data)
 static ssize_t device_name_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
+	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 	ssize_t len;
 
 	spin_lock_bh(&trigger_data->lock);
@@ -109,8 +108,7 @@ static ssize_t device_name_store(struct device *dev,
 				 struct device_attribute *attr, const char *buf,
 				 size_t size)
 {
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
+	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 
 	if (size >= IFNAMSIZ)
 		return -EINVAL;
@@ -150,8 +148,7 @@ static DEVICE_ATTR_RW(device_name);
 static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
 	enum netdev_led_attr attr)
 {
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
+	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 	int bit;
 
 	switch (attr) {
@@ -174,8 +171,7 @@ static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
 static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
 	size_t size, enum netdev_led_attr attr)
 {
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
+	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 	unsigned long state;
 	int ret;
 	int bit;
@@ -255,8 +251,7 @@ static DEVICE_ATTR_RW(rx);
 static ssize_t interval_show(struct device *dev,
 			     struct device_attribute *attr, char *buf)
 {
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
+	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 
 	return sprintf(buf, "%u\n",
 		       jiffies_to_msecs(atomic_read(&trigger_data->interval)));
@@ -266,8 +261,7 @@ static ssize_t interval_store(struct device *dev,
 			      struct device_attribute *attr, const char *buf,
 			      size_t size)
 {
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
+	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
 	unsigned long value;
 	int ret;
 
@@ -288,15 +282,23 @@ 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)
 {
 	struct net_device *dev =
 		netdev_notifier_info_to_dev((struct netdev_notifier_info *)dv);
-	struct led_netdev_data *trigger_data = container_of(nb,
-							    struct
-							    led_netdev_data,
-							    notifier);
+	struct led_netdev_data *trigger_data =
+		container_of(nb, struct led_netdev_data, notifier);
 
 	if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
 	    && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
@@ -342,10 +344,8 @@ static int netdev_trig_notify(struct notifier_block *nb,
 /* here's the real work! */
 static void netdev_trig_work(struct work_struct *work)
 {
-	struct led_netdev_data *trigger_data = container_of(work,
-							    struct
-							    led_netdev_data,
-							    work.work);
+	struct led_netdev_data *trigger_data =
+		container_of(work, struct led_netdev_data, work.work);
 	struct rtnl_link_stats64 *dev_stats;
 	unsigned int new_activity;
 	struct rtnl_link_stats64 temp;
@@ -395,7 +395,7 @@ static int netdev_trig_activate(struct led_classdev *led_cdev)
 
 	trigger_data = kzalloc(sizeof(struct led_netdev_data), GFP_KERNEL);
 	if (!trigger_data)
-		return 0;
+		return -ENOMEM;
 
 	spin_lock_init(&trigger_data->lock);
 
@@ -412,71 +412,34 @@ static int netdev_trig_activate(struct led_classdev *led_cdev)
 	atomic_set(&trigger_data->interval, msecs_to_jiffies(50));
 	trigger_data->last_activity = 0;
 
-	led_cdev->trigger_data = trigger_data;
+	led_set_trigger_data(led_cdev, 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 0;
-
-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 0;
+	return rc;
 }
 
 static void netdev_trig_deactivate(struct led_classdev *led_cdev)
 {
-	struct led_netdev_data *trigger_data = led_cdev->trigger_data;
+	struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);
 
-	if (trigger_data) {
-		unregister_netdevice_notifier(&trigger_data->notifier);
+	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);
-
-		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,
 	.deactivate = netdev_trig_deactivate,
+	.groups = netdev_trig_groups,
 };
 
 static int __init netdev_trig_init(void)