[PATCH] add netdev led trigger

[Eric Cooper]

Add a netdev LED trigger for all Blinkenlights lovers...
Originally taken from https://dev.openwrt.org/ticket/2776
Slightly updated for 2.6.24 by Mickey Lauer <mickey@xxxxxxxxxxxx>
and for 2.6.36 by Eric Cooper <ecc@xxxxxxx>

Signed-off-by: Eric Cooper <ecc@xxxxxxx>
---
 drivers/leds/Kconfig          |    7 +
 drivers/leds/Makefile         |    1 +
 drivers/leds/ledtrig-netdev.c |  463 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 471 insertions(+), 0 deletions(-)
 create mode 100644 drivers/leds/ledtrig-netdev.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index 77b8fd2..8d81cd0 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -374,6 +374,13 @@ config LEDS_TRIGGER_HEARTBEAT
 	  load average.
 	  If unsure, say Y.
 
+config LEDS_TRIGGER_NETDEV
+	tristate "LED Network Device Trigger"
+	depends on NET
+	help
+	  This allows LEDs to be controlled by network device activity.
+	  If unsure, say Y.
+
 config LEDS_TRIGGER_BACKLIGHT
 	tristate "LED backlight Trigger"
 	help
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index aae6989..a3bb67d 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_LEDS_DAC124S085)		+= leds-dac124s085.o
 obj-$(CONFIG_LEDS_TRIGGER_TIMER)	+= ledtrig-timer.o
 obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK)	+= ledtrig-ide-disk.o
 obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT)	+= ledtrig-heartbeat.o
+obj-$(CONFIG_LEDS_TRIGGER_NETDEV)	+= ledtrig-netdev.o
 obj-$(CONFIG_LEDS_TRIGGER_BACKLIGHT)	+= ledtrig-backlight.o
 obj-$(CONFIG_LEDS_TRIGGER_GPIO)		+= ledtrig-gpio.o
 obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON)	+= ledtrig-default-on.o
diff --git a/drivers/leds/ledtrig-netdev.c b/drivers/leds/ledtrig-netdev.c
new file mode 100644
index 0000000..ebf9b6b
--- /dev/null
+++ b/drivers/leds/ledtrig-netdev.c
@@ -0,0 +1,463 @@
+/*
+ * LED Kernel Netdev Trigger
+ *
+ * Toggles the LED to reflect the link and traffic state of a named net device
+ *
+ * Copyright 2007 Oliver Jowett <oliver@xxxxxxxxxxxxx>
+ *
+ * Derived from ledtrig-timer.c which is:
+ *  Copyright 2005-2006 Openedhand Ltd.
+ *  Author: Richard Purdie <rpurdie@xxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/sysdev.h>
+#include <linux/netdevice.h>
+#include <linux/timer.h>
+#include <linux/ctype.h>
+#include <linux/leds.h>
+#include <linux/version.h>
+#include <net/net_namespace.h>
+
+#include "leds.h"
+
+/*
+ * Configurable sysfs attributes:
+ *
+ * device_name - network device name to monitor
+ *
+ * interval - duration of LED blink, in milliseconds
+ *
+ * mode - either "none" (LED is off) or a space separated list
+ * of one or more of:
+ *   link: LED's normal state reflects whether the link is up (has carrier)
+ *         or not
+ *   tx:   LED blinks on transmitted data
+ *   rx:   LED blinks on receive data
+ *
+ * Some suggestions:
+ *
+ *  Simple link status LED:
+ *  $ echo netdev >someled/trigger
+ *  $ echo eth0 >someled/device_name
+ *  $ echo link >someled/mode
+ *
+ *  Ethernet-style link/activity LED:
+ *  $ echo netdev >someled/trigger
+ *  $ echo eth0 >someled/device_name
+ *  $ echo "link tx rx" >someled/mode
+ *
+ *  Modem-style tx/rx LEDs:
+ *  $ echo netdev >led1/trigger
+ *  $ echo ppp0 >led1/device_name
+ *  $ echo tx >led1/mode
+ *  $ echo netdev >led2/trigger
+ *  $ echo ppp0 >led2/device_name
+ *  $ echo rx >led2/mode
+ *
+ */
+
+#define MODE_LINK 1
+#define MODE_TX	  2
+#define MODE_RX	  4
+
+struct led_netdev_data {
+	rwlock_t lock;
+
+	struct timer_list timer;
+	struct notifier_block notifier;
+
+	struct led_classdev *led_cdev;
+	struct net_device *net_dev;
+
+	char device_name[IFNAMSIZ];
+	unsigned interval;
+	unsigned mode;
+	unsigned link_up;
+	unsigned last_activity;
+};
+
+static void set_baseline_state(struct led_netdev_data *trigger_data)
+{
+	if ((trigger_data->mode & MODE_LINK) != 0 && trigger_data->link_up)
+		led_set_brightness(trigger_data->led_cdev, LED_FULL);
+	else
+		led_set_brightness(trigger_data->led_cdev, LED_OFF);
+
+	if ((trigger_data->mode & (MODE_TX | MODE_RX)) != 0 &&
+	    trigger_data->link_up)
+		mod_timer(&trigger_data->timer,
+			  jiffies + trigger_data->interval);
+	else
+		del_timer(&trigger_data->timer);
+}
+
+static ssize_t led_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;
+
+	read_lock(&trigger_data->lock);
+	sprintf(buf, "%s\n", trigger_data->device_name);
+	read_unlock(&trigger_data->lock);
+
+	return strlen(buf) + 1;
+}
+
+static ssize_t led_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;
+
+	if (size < 0 || size >= IFNAMSIZ)
+		return -EINVAL;
+
+	write_lock(&trigger_data->lock);
+
+	strcpy(trigger_data->device_name, buf);
+	if (size > 0 && trigger_data->device_name[size-1] == '\n')
+		trigger_data->device_name[size-1] = 0;
+
+	if (trigger_data->device_name[0] != 0) {
+		/* check for existing device to update from */
+		struct net_device *dev =
+			dev_get_by_name(&init_net, trigger_data->device_name);
+		if (dev != NULL) {
+			unsigned int flags = dev_get_flags(dev);
+			trigger_data->net_dev = dev;
+			trigger_data->link_up = (flags & IFF_LOWER_UP) != 0;
+		}
+		/* updates LEDs, may start timers */
+		set_baseline_state(trigger_data);
+	}
+
+	write_unlock(&trigger_data->lock);
+	return size;
+}
+
+static DEVICE_ATTR(device_name, 0644,
+		   led_device_name_show, led_device_name_store);
+
+static ssize_t led_mode_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;
+
+	read_lock(&trigger_data->lock);
+
+	if (trigger_data->mode == 0) {
+		strcpy(buf, "none\n");
+	} else {
+		if (trigger_data->mode & MODE_LINK)
+			strcat(buf, "link ");
+		if (trigger_data->mode & MODE_TX)
+			strcat(buf, "tx ");
+		if (trigger_data->mode & MODE_RX)
+			strcat(buf, "rx ");
+		strcat(buf, "\n");
+	}
+
+	read_unlock(&trigger_data->lock);
+
+	return strlen(buf)+1;
+}
+
+static ssize_t led_mode_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;
+	char copybuf[32];
+	int new_mode = -1;
+	char *p, *token;
+
+	/* take a copy since we don't want to trash the inbound buffer
+	   when using strsep */
+	strncpy(copybuf, buf, sizeof(copybuf));
+	copybuf[sizeof(copybuf) - 1] = '\0';
+	p = copybuf;
+
+	while ((token = strsep(&p, " \t\n")) != NULL) {
+		if (!*token)
+			continue;
+
+		if (new_mode == -1)
+			new_mode = 0;
+
+		if (!strcmp(token, "none"))
+			new_mode = 0;
+		else if (!strcmp(token, "tx"))
+			new_mode |= MODE_TX;
+		else if (!strcmp(token, "rx"))
+			new_mode |= MODE_RX;
+		else if (!strcmp(token, "link"))
+			new_mode |= MODE_LINK;
+		else
+			return -EINVAL;
+	}
+
+	if (new_mode == -1)
+		return -EINVAL;
+
+	write_lock(&trigger_data->lock);
+	trigger_data->mode = new_mode;
+	set_baseline_state(trigger_data);
+	write_unlock(&trigger_data->lock);
+
+	return size;
+}
+
+static DEVICE_ATTR(mode, 0644, led_mode_show, led_mode_store);
+
+static ssize_t led_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;
+
+	read_lock(&trigger_data->lock);
+	sprintf(buf, "%u\n", jiffies_to_msecs(trigger_data->interval));
+	read_unlock(&trigger_data->lock);
+
+	return strlen(buf) + 1;
+}
+
+static ssize_t led_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;
+	int ret = -EINVAL;
+	char *after;
+	unsigned long value = simple_strtoul(buf, &after, 10);
+	size_t count = after - buf;
+
+	if (*after && isspace(*after))
+		count++;
+
+	/* impose some basic bounds on the timer interval */
+	if (count == size && value >= 5 && value <= 10000) {
+		write_lock(&trigger_data->lock);
+		trigger_data->interval = msecs_to_jiffies(value);
+		set_baseline_state(trigger_data);	/* resets timer */
+		write_unlock(&trigger_data->lock);
+		ret = count;
+	}
+
+	return ret;
+}
+
+static DEVICE_ATTR(interval, 0644, led_interval_show, led_interval_store);
+
+static int netdev_trig_notify(struct notifier_block *nb,
+			      unsigned long evt,
+			      void *dv)
+{
+	struct net_device *dev = dv;
+	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)
+		return NOTIFY_DONE;
+
+	write_lock(&trigger_data->lock);
+
+	if (strcmp(dev->name, trigger_data->device_name))
+		goto done;
+
+	if (evt == NETDEV_REGISTER) {
+		if (trigger_data->net_dev != NULL)
+			dev_put(trigger_data->net_dev);
+		dev_hold(dev);
+		trigger_data->net_dev = dev;
+		trigger_data->link_up = 0;
+		goto done;
+	}
+
+	if (evt == NETDEV_UNREGISTER && trigger_data->net_dev != NULL) {
+		dev_put(trigger_data->net_dev);
+		trigger_data->net_dev = NULL;
+		goto done;
+	}
+
+	/* UP / DOWN / CHANGE */
+
+	trigger_data->link_up = (evt != NETDEV_DOWN && netif_carrier_ok(dev));
+	set_baseline_state(trigger_data);
+
+done:
+	write_unlock(&trigger_data->lock);
+	return NOTIFY_DONE;
+}
+
+/* here's the real work! */
+static void netdev_trig_timer(unsigned long arg)
+{
+	struct led_netdev_data *trigger_data = (struct led_netdev_data *)arg;
+	struct rtnl_link_stats64 temp;
+	const struct rtnl_link_stats64 *dev_stats;
+	unsigned new_activity;
+
+	write_lock(&trigger_data->lock);
+
+	if (!trigger_data->link_up || !trigger_data->net_dev ||
+	    (trigger_data->mode & (MODE_TX | MODE_RX)) == 0) {
+		/* we don't need to do timer work, just reflect link state. */
+		int on = (trigger_data->mode & MODE_LINK) != 0 &&
+			trigger_data->link_up;
+		led_set_brightness(trigger_data->led_cdev,
+				   on ? LED_FULL : LED_OFF);
+		goto no_restart;
+	}
+
+	dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
+
+	new_activity =
+		((trigger_data->mode & MODE_TX) ? dev_stats->tx_packets : 0) +
+		((trigger_data->mode & MODE_RX) ? dev_stats->rx_packets : 0);
+
+	if (trigger_data->mode & MODE_LINK) {
+		/* base state is ON (link present) */
+		/* if there's no link, we don't get this far
+		   and the LED is off */
+
+		/* OFF -> ON always */
+		/* ON -> OFF on activity */
+		if (trigger_data->led_cdev->brightness == LED_OFF)
+			led_set_brightness(trigger_data->led_cdev, LED_FULL);
+		else if (trigger_data->last_activity != new_activity)
+			led_set_brightness(trigger_data->led_cdev, LED_OFF);
+	} else {
+		/* base state is OFF */
+		/* ON -> OFF always */
+		/* OFF -> ON on activity */
+		if (trigger_data->led_cdev->brightness == LED_FULL)
+			led_set_brightness(trigger_data->led_cdev, LED_OFF);
+		else if (trigger_data->last_activity != new_activity)
+			led_set_brightness(trigger_data->led_cdev, LED_FULL);
+	}
+
+	trigger_data->last_activity = new_activity;
+	mod_timer(&trigger_data->timer, jiffies + trigger_data->interval);
+
+no_restart:
+	write_unlock(&trigger_data->lock);
+}
+
+static void 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;
+
+	rwlock_init(&trigger_data->lock);
+
+	trigger_data->notifier.notifier_call = netdev_trig_notify;
+	trigger_data->notifier.priority = 10;
+
+	setup_timer(&trigger_data->timer, netdev_trig_timer,
+		    (unsigned long) trigger_data);
+
+	trigger_data->led_cdev = led_cdev;
+	trigger_data->net_dev = NULL;
+	trigger_data->device_name[0] = 0;
+
+	trigger_data->mode = 0;
+	trigger_data->interval = msecs_to_jiffies(50);
+	trigger_data->link_up = 0;
+	trigger_data->last_activity = 0;
+
+	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_mode);
+	if (rc)
+		goto err_out_device_name;
+	rc = device_create_file(led_cdev->dev, &dev_attr_interval);
+	if (rc)
+		goto err_out_mode;
+
+	register_netdevice_notifier(&trigger_data->notifier);
+	return;
+
+err_out_mode:
+	device_remove_file(led_cdev->dev, &dev_attr_mode);
+err_out_device_name:
+	device_remove_file(led_cdev->dev, &dev_attr_device_name);
+err_out:
+	led_cdev->trigger_data = NULL;
+	kfree(trigger_data);
+}
+
+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_mode);
+		device_remove_file(led_cdev->dev, &dev_attr_interval);
+
+		write_lock(&trigger_data->lock);
+
+		if (trigger_data->net_dev) {
+			dev_put(trigger_data->net_dev);
+			trigger_data->net_dev = NULL;
+		}
+
+		write_unlock(&trigger_data->lock);
+
+		del_timer_sync(&trigger_data->timer);
+
+		kfree(trigger_data);
+	}
+}
+
+static struct led_trigger netdev_led_trigger = {
+	.name	  = "netdev",
+	.activate = netdev_trig_activate,
+	.deactivate = netdev_trig_deactivate,
+};
+
+static int __init netdev_trig_init(void)
+{
+	return led_trigger_register(&netdev_led_trigger);
+}
+
+static void __exit netdev_trig_exit(void)
+{
+	led_trigger_unregister(&netdev_led_trigger);
+}
+
+module_init(netdev_trig_init);
+module_exit(netdev_trig_exit);
+
+MODULE_AUTHOR("Oliver Jowett <oliver@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Netdev LED trigger");
+MODULE_LICENSE("GPL");
-- 
1.7.2.3

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