// SPDX-License-Identifier: GPL-2.0
// Copyright 2017 Ben Whitten <ben.whitten@gmail.com>
// Copyright 2007 Oliver Jowett <oliver@opencloud.com>
//
// LED Kernel Netdev Trigger
//
// Toggles the LED to reflect the link and traffic state of a named net device
//
// Derived from ledtrig-timer.c which is:
//  Copyright 2005-2006 Openedhand Ltd.
//  Author: Richard Purdie <rpurdie@openedhand.com>

#include <linux/atomic.h>
#include <linux/ctype.h>
#include <linux/device.h>
#include <linux/ethtool.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/leds.h>
#include <linux/linkmode.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/mutex.h>
#include <linux/phy.h>
#include <linux/rtnetlink.h>
#include <linux/timer.h>
#include "../leds.h"

#define NETDEV_LED_DEFAULT_INTERVAL     50

/*
 * Configurable sysfs attributes:
 *
 * device_name - network device name to monitor
 * interval - duration of LED blink, in milliseconds
 * 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
 * tx_err -  LED blinks on transmit error
 * rx_err -  LED blinks on receive error
 *
 * Note: If the user selects a mode that is not supported by hw, default
 * behavior is to fall back to software control of the LED. However not every
 * hw supports software control. LED callbacks brightness_set() and
 * brightness_set_blocking() are NULL in this case. hw_control_is_supported()
 * should use available means supported by hw to inform the user that selected
 * mode isn't supported by hw. This could be switching off the LED or any
 * hw blink mode. If software control fallback isn't possible, we return
 * -EOPNOTSUPP to the user, but still store the selected mode. This is needed
 * in case an intermediate unsupported mode is necessary to switch from one
 * supported mode to another.
 */

struct led_netdev_data {
        struct mutex lock;

        struct delayed_work work;
        struct notifier_block notifier;

        struct led_classdev *led_cdev;
        struct net_device *net_dev;

        char device_name[IFNAMSIZ];
        atomic_t interval;
        unsigned int last_activity;

        unsigned long mode;
        int link_speed;
        __ETHTOOL_DECLARE_LINK_MODE_MASK(supported_link_modes);
        u8 duplex;

        bool carrier_link_up;
        bool hw_control;
};

static const struct attribute_group netdev_trig_link_speed_attrs_group;

static void set_baseline_state(struct led_netdev_data *trigger_data)
{
        int current_brightness;
        struct led_classdev *led_cdev = trigger_data->led_cdev;

        /* Already validated, hw control is possible with the requested mode */
        if (trigger_data->hw_control) {
                led_cdev->hw_control_set(led_cdev, trigger_data->mode);

                return;
        }

        current_brightness = led_cdev->brightness;
        if (current_brightness)
                led_cdev->blink_brightness = current_brightness;
        if (!led_cdev->blink_brightness)
                led_cdev->blink_brightness = led_cdev->max_brightness;

        if (!trigger_data->carrier_link_up) {
                led_set_brightness(led_cdev, LED_OFF);
        } else {
                bool blink_on = false;

                if (test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode))
                        blink_on = true;

                if (test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) &&
                    trigger_data->link_speed == SPEED_10)
                        blink_on = true;

                if (test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) &&
                    trigger_data->link_speed == SPEED_100)
                        blink_on = true;

                if (test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) &&
                    trigger_data->link_speed == SPEED_1000)
                        blink_on = true;

                if (test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) &&
                    trigger_data->link_speed == SPEED_2500)
                        blink_on = true;

                if (test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) &&
                    trigger_data->link_speed == SPEED_5000)
                        blink_on = true;

                if (test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) &&
                    trigger_data->link_speed == SPEED_10000)
                        blink_on = true;

                if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) &&
                    trigger_data->duplex == DUPLEX_HALF)
                        blink_on = true;

                if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode) &&
                    trigger_data->duplex == DUPLEX_FULL)
                        blink_on = true;

                if (blink_on)
                        led_set_brightness(led_cdev,
                                           led_cdev->blink_brightness);
                else
                        led_set_brightness(led_cdev, LED_OFF);

                /* If we are looking for RX/TX start periodically
                 * checking stats
                 */
                if (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ||
                    test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ||
                    test_bit(TRIGGER_NETDEV_TX_ERR, &trigger_data->mode) ||
                    test_bit(TRIGGER_NETDEV_RX_ERR, &trigger_data->mode))
                        schedule_delayed_work(&trigger_data->work, 0);
        }
}

static bool supports_hw_control(struct led_classdev *led_cdev)
{
        if (!led_cdev->hw_control_get || !led_cdev->hw_control_set ||
            !led_cdev->hw_control_is_supported)
                return false;

        return !strcmp(led_cdev->hw_control_trigger, led_cdev->trigger->name);
}

/*
 * Validate the configured netdev is the same as the one associated with
 * the LED driver in hw control.
 */
static bool validate_net_dev(struct led_classdev *led_cdev,
                             struct net_device *net_dev)
{
        struct device *dev = led_cdev->hw_control_get_device(led_cdev);
        struct net_device *ndev;

        if (!dev)
                return false;

        ndev = to_net_dev(dev);

        return ndev == net_dev;
}

static bool can_hw_control(struct led_netdev_data *trigger_data)
{
        unsigned long default_interval = msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL);
        unsigned int interval = atomic_read(&trigger_data->interval);
        struct led_classdev *led_cdev = trigger_data->led_cdev;
        int ret;

        if (!supports_hw_control(led_cdev))
                return false;

        /*
         * Interval must be set to the default
         * value. Any different value is rejected if in hw
         * control.
         */
        if (interval != default_interval)
                return false;

        /*
         * net_dev must be set with hw control, otherwise no
         * blinking can be happening and there is nothing to
         * offloaded. Additionally, for hw control to be
         * valid, the configured netdev must be the same as
         * netdev associated to the LED.
         */
        if (!validate_net_dev(led_cdev, trigger_data->net_dev))
                return false;

        /* Check if the requested mode is supported */
        ret = led_cdev->hw_control_is_supported(led_cdev, trigger_data->mode);
        /* Fall back to software blinking if not supported */
        if (ret == -EOPNOTSUPP)
                return false;
        if (ret) {
                dev_warn(led_cdev->dev,
                         "Current mode check failed with error %d\n", ret);
                return false;
        }

        return true;
}

static void get_device_state(struct led_netdev_data *trigger_data)
{
        struct ethtool_link_ksettings cmd;

        trigger_data->carrier_link_up = netif_carrier_ok(trigger_data->net_dev);

        if (__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd))
                return;

        if (trigger_data->carrier_link_up) {
                trigger_data->link_speed = cmd.base.speed;
                trigger_data->duplex = cmd.base.duplex;
        }

        /*
         * Have a local copy of the link speed supported to avoid rtnl lock every time
         * modes are refreshed on any change event
         */
        linkmode_copy(trigger_data->supported_link_modes, cmd.link_modes.supported);
}

static ssize_t device_name_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
        ssize_t len;

        mutex_lock(&trigger_data->lock);
        len = sprintf(buf, "%s\n", trigger_data->device_name);
        mutex_unlock(&trigger_data->lock);

        return len;
}

static int set_device_name(struct led_netdev_data *trigger_data,
                           const char *name, size_t size)
{
        if (size >= IFNAMSIZ)
                return -EINVAL;

        cancel_delayed_work_sync(&trigger_data->work);

        /*
         * Take RTNL lock before trigger_data lock to prevent potential
         * deadlock with netdev notifier registration.
         */
        rtnl_lock();
        mutex_lock(&trigger_data->lock);

        if (trigger_data->net_dev) {
                dev_put(trigger_data->net_dev);
                trigger_data->net_dev = NULL;
        }

        memcpy(trigger_data->device_name, name, size);
        trigger_data->device_name[size] = 0;
        if (size > 0 && trigger_data->device_name[size - 1] == '\n')
                trigger_data->device_name[size - 1] = 0;

        if (trigger_data->device_name[0] != 0)
                trigger_data->net_dev =
                    dev_get_by_name(&init_net, trigger_data->device_name);

        trigger_data->carrier_link_up = false;
        trigger_data->link_speed = SPEED_UNKNOWN;
        trigger_data->duplex = DUPLEX_UNKNOWN;
        if (trigger_data->net_dev)
                get_device_state(trigger_data);

        trigger_data->last_activity = 0;

        /* Skip if we're called from netdev_trig_activate() and hw_control is true */
        if (!trigger_data->hw_control || led_get_trigger_data(trigger_data->led_cdev))
                set_baseline_state(trigger_data);

        mutex_unlock(&trigger_data->lock);
        rtnl_unlock();

        return 0;
}

static ssize_t device_name_store(struct device *dev,
                                 struct device_attribute *attr, const char *buf,
                                 size_t size)
{
        struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
        int ret;

        ret = set_device_name(trigger_data, buf, size);

        if (ret < 0)
                return ret;

        /* Refresh link_speed visibility */
        sysfs_update_group(&dev->kobj, &netdev_trig_link_speed_attrs_group);

        return size;
}

static DEVICE_ATTR_RW(device_name);

static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
                                    enum led_trigger_netdev_modes attr)
{
        struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
        int bit;

        switch (attr) {
        case TRIGGER_NETDEV_LINK:
        case TRIGGER_NETDEV_LINK_10:
        case TRIGGER_NETDEV_LINK_100:
        case TRIGGER_NETDEV_LINK_1000:
        case TRIGGER_NETDEV_LINK_2500:
        case TRIGGER_NETDEV_LINK_5000:
        case TRIGGER_NETDEV_LINK_10000:
        case TRIGGER_NETDEV_HALF_DUPLEX:
        case TRIGGER_NETDEV_FULL_DUPLEX:
        case TRIGGER_NETDEV_TX:
        case TRIGGER_NETDEV_RX:
        case TRIGGER_NETDEV_TX_ERR:
        case TRIGGER_NETDEV_RX_ERR:
                bit = attr;
                break;
        default:
                return -EINVAL;
        }

        return sprintf(buf, "%u\n", test_bit(bit, &trigger_data->mode));
}

static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
                                     size_t size, enum led_trigger_netdev_modes attr)
{
        struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
        struct led_classdev *led_cdev = trigger_data->led_cdev;
        unsigned long state, mode = trigger_data->mode;
        int ret;
        int bit;

        ret = kstrtoul(buf, 0, &state);
        if (ret)
                return ret;

        switch (attr) {
        case TRIGGER_NETDEV_LINK:
        case TRIGGER_NETDEV_LINK_10:
        case TRIGGER_NETDEV_LINK_100:
        case TRIGGER_NETDEV_LINK_1000:
        case TRIGGER_NETDEV_LINK_2500:
        case TRIGGER_NETDEV_LINK_5000:
        case TRIGGER_NETDEV_LINK_10000:
        case TRIGGER_NETDEV_HALF_DUPLEX:
        case TRIGGER_NETDEV_FULL_DUPLEX:
        case TRIGGER_NETDEV_TX:
        case TRIGGER_NETDEV_RX:
        case TRIGGER_NETDEV_TX_ERR:
        case TRIGGER_NETDEV_RX_ERR:
                bit = attr;
                break;
        default:
                return -EINVAL;
        }

        if (state)
                set_bit(bit, &mode);
        else
                clear_bit(bit, &mode);

        if (test_bit(TRIGGER_NETDEV_LINK, &mode) &&
            (test_bit(TRIGGER_NETDEV_LINK_10, &mode) ||
             test_bit(TRIGGER_NETDEV_LINK_100, &mode) ||
             test_bit(TRIGGER_NETDEV_LINK_1000, &mode) ||
             test_bit(TRIGGER_NETDEV_LINK_2500, &mode) ||
             test_bit(TRIGGER_NETDEV_LINK_5000, &mode) ||
             test_bit(TRIGGER_NETDEV_LINK_10000, &mode)))
                return -EINVAL;

        cancel_delayed_work_sync(&trigger_data->work);

        trigger_data->mode = mode;
        trigger_data->hw_control = can_hw_control(trigger_data);

        if (!led_cdev->brightness_set && !led_cdev->brightness_set_blocking &&
            !trigger_data->hw_control)
                return -EOPNOTSUPP;

        set_baseline_state(trigger_data);

        return size;
}

#define DEFINE_NETDEV_TRIGGER(trigger_name, trigger) \
        static ssize_t trigger_name##_show(struct device *dev, \
                struct device_attribute *attr, char *buf) \
        { \
                return netdev_led_attr_show(dev, buf, trigger); \
        } \
        static ssize_t trigger_name##_store(struct device *dev, \
                struct device_attribute *attr, const char *buf, size_t size) \
        { \
                return netdev_led_attr_store(dev, buf, size, trigger); \
        } \
        static DEVICE_ATTR_RW(trigger_name)

DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
DEFINE_NETDEV_TRIGGER(link_2500, TRIGGER_NETDEV_LINK_2500);
DEFINE_NETDEV_TRIGGER(link_5000, TRIGGER_NETDEV_LINK_5000);
DEFINE_NETDEV_TRIGGER(link_10000, TRIGGER_NETDEV_LINK_10000);
DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
DEFINE_NETDEV_TRIGGER(tx_err, TRIGGER_NETDEV_TX_ERR);
DEFINE_NETDEV_TRIGGER(rx_err, TRIGGER_NETDEV_RX_ERR);

static ssize_t interval_show(struct device *dev,
                             struct device_attribute *attr, char *buf)
{
        struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);

        return sprintf(buf, "%u\n",
                       jiffies_to_msecs(atomic_read(&trigger_data->interval)));
}

static ssize_t interval_store(struct device *dev,
                              struct device_attribute *attr, const char *buf,
                              size_t size)
{
        struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
        unsigned long value;
        int ret;

        if (trigger_data->hw_control)
                return -EINVAL;

        ret = kstrtoul(buf, 0, &value);
        if (ret)
                return ret;

        /* impose some basic bounds on the timer interval */
        if (value >= 5 && value <= 10000) {
                cancel_delayed_work_sync(&trigger_data->work);

                atomic_set(&trigger_data->interval, msecs_to_jiffies(value));
                set_baseline_state(trigger_data);       /* resets timer */
        }

        return size;
}

static DEVICE_ATTR_RW(interval);

static ssize_t offloaded_show(struct device *dev,
                              struct device_attribute *attr, char *buf)
{
        struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);

        return sprintf(buf, "%d\n", trigger_data->hw_control);
}

static DEVICE_ATTR_RO(offloaded);

#define CHECK_LINK_MODE_ATTR(link_speed) \
        do { \
                if (attr == &dev_attr_link_##link_speed.attr && \
                    link_ksettings.base.speed == SPEED_##link_speed) \
                        return attr->mode; \
        } while (0)

static umode_t netdev_trig_link_speed_visible(struct kobject *kobj,
                                              struct attribute *attr, int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct led_netdev_data *trigger_data;
        unsigned long *supported_link_modes;
        u32 mode;

        trigger_data = led_trigger_get_drvdata(dev);
        supported_link_modes = trigger_data->supported_link_modes;

        /*
         * Search in the supported link mode mask a matching supported mode.
         * Stop at the first matching entry as we care only to check if a particular
         * speed is supported and not the kind.
         */
        for_each_set_bit(mode, supported_link_modes, __ETHTOOL_LINK_MODE_MASK_NBITS) {
                struct ethtool_link_ksettings link_ksettings;

                ethtool_params_from_link_mode(&link_ksettings, mode);

                CHECK_LINK_MODE_ATTR(10);
                CHECK_LINK_MODE_ATTR(100);
                CHECK_LINK_MODE_ATTR(1000);
                CHECK_LINK_MODE_ATTR(2500);
                CHECK_LINK_MODE_ATTR(5000);
                CHECK_LINK_MODE_ATTR(10000);
        }

        return 0;
}

static struct attribute *netdev_trig_link_speed_attrs[] = {
        &dev_attr_link_10.attr,
        &dev_attr_link_100.attr,
        &dev_attr_link_1000.attr,
        &dev_attr_link_2500.attr,
        &dev_attr_link_5000.attr,
        &dev_attr_link_10000.attr,
        NULL
};

static const struct attribute_group netdev_trig_link_speed_attrs_group = {
        .attrs = netdev_trig_link_speed_attrs,
        .is_visible = netdev_trig_link_speed_visible,
};

static struct attribute *netdev_trig_attrs[] = {
        &dev_attr_device_name.attr,
        &dev_attr_link.attr,
        &dev_attr_full_duplex.attr,
        &dev_attr_half_duplex.attr,
        &dev_attr_rx.attr,
        &dev_attr_tx.attr,
        &dev_attr_rx_err.attr,
        &dev_attr_tx_err.attr,
        &dev_attr_interval.attr,
        &dev_attr_offloaded.attr,
        NULL
};

static const struct attribute_group netdev_trig_attrs_group = {
        .attrs = netdev_trig_attrs,
};

static const struct attribute_group *netdev_trig_groups[] = {
        &netdev_trig_attrs_group,
        &netdev_trig_link_speed_attrs_group,
        NULL,
};

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_classdev *led_cdev = trigger_data->led_cdev;

        if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
            && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
            && evt != NETDEV_CHANGENAME)
                return NOTIFY_DONE;

        if (!(dev == trigger_data->net_dev ||
              (evt == NETDEV_CHANGENAME && !strcmp(dev->name, trigger_data->device_name)) ||
              (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
                return NOTIFY_DONE;

        cancel_delayed_work_sync(&trigger_data->work);

        mutex_lock(&trigger_data->lock);

        trigger_data->carrier_link_up = false;
        trigger_data->link_speed = SPEED_UNKNOWN;
        trigger_data->duplex = DUPLEX_UNKNOWN;
        switch (evt) {
        case NETDEV_CHANGENAME:
        case NETDEV_REGISTER:
                dev_put(trigger_data->net_dev);
                dev_hold(dev);
                trigger_data->net_dev = dev;
                if (evt == NETDEV_CHANGENAME)
                        get_device_state(trigger_data);
                break;
        case NETDEV_UNREGISTER:
                dev_put(trigger_data->net_dev);
                trigger_data->net_dev = NULL;
                break;
        case NETDEV_UP:
                trigger_data->hw_control = can_hw_control(trigger_data);
                fallthrough;
        case NETDEV_CHANGE:
                get_device_state(trigger_data);
                /* Refresh link_speed visibility */
                if (evt == NETDEV_CHANGE)
                        sysfs_update_group(&led_cdev->dev->kobj,
                                           &netdev_trig_link_speed_attrs_group);
                break;
        }

        set_baseline_state(trigger_data);

        mutex_unlock(&trigger_data->lock);

        return NOTIFY_DONE;
}

/* 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 rtnl_link_stats64 *dev_stats;
        unsigned int new_activity;
        struct rtnl_link_stats64 temp;
        unsigned long interval;
        int invert;

        /* If we dont have a device, insure we are off */
        if (!trigger_data->net_dev) {
                led_set_brightness(trigger_data->led_cdev, LED_OFF);
                return;
        }

        /* If we are not looking for RX/TX then return  */
        if (!test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) &&
            !test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) &&
            !test_bit(TRIGGER_NETDEV_TX_ERR, &trigger_data->mode) &&
            !test_bit(TRIGGER_NETDEV_RX_ERR, &trigger_data->mode))
                return;

        dev_stats = dev_get_stats(trigger_data->net_dev, &temp);
        new_activity =
            (test_bit(TRIGGER_NETDEV_TX, &trigger_data->mode) ?
                dev_stats->tx_packets : 0) +
            (test_bit(TRIGGER_NETDEV_RX, &trigger_data->mode) ?
                dev_stats->rx_packets : 0) +
            (test_bit(TRIGGER_NETDEV_TX_ERR, &trigger_data->mode) ?
                dev_stats->tx_errors : 0) +
            (test_bit(TRIGGER_NETDEV_RX_ERR, &trigger_data->mode) ?
                dev_stats->rx_errors : 0);

        if (trigger_data->last_activity != new_activity) {
                led_stop_software_blink(trigger_data->led_cdev);

                invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
                         test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
                         test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
                         test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
                         test_bit(TRIGGER_NETDEV_LINK_2500, &trigger_data->mode) ||
                         test_bit(TRIGGER_NETDEV_LINK_5000, &trigger_data->mode) ||
                         test_bit(TRIGGER_NETDEV_LINK_10000, &trigger_data->mode) ||
                         test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
                         test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
                interval = jiffies_to_msecs(
                                atomic_read(&trigger_data->interval));
                /* base state is ON (link present) */
                led_blink_set_oneshot(trigger_data->led_cdev,
                                      &interval,
                                      &interval,
                                      invert);
                trigger_data->last_activity = new_activity;
        }

        schedule_delayed_work(&trigger_data->work,
                        (atomic_read(&trigger_data->interval)*2));
}

static int netdev_trig_activate(struct led_classdev *led_cdev)
{
        struct led_netdev_data *trigger_data;
        unsigned long mode = 0;
        struct device *dev;
        int rc;

        trigger_data = kzalloc_obj(struct led_netdev_data);
        if (!trigger_data)
                return -ENOMEM;

        mutex_init(&trigger_data->lock);

        trigger_data->notifier.notifier_call = netdev_trig_notify;
        trigger_data->notifier.priority = 10;

        INIT_DELAYED_WORK(&trigger_data->work, netdev_trig_work);

        trigger_data->led_cdev = led_cdev;
        trigger_data->net_dev = NULL;
        trigger_data->device_name[0] = 0;

        trigger_data->mode = 0;
        atomic_set(&trigger_data->interval, msecs_to_jiffies(NETDEV_LED_DEFAULT_INTERVAL));
        trigger_data->last_activity = 0;

        /* Check if hw control is active by default on the LED.
         * Init already enabled mode in hw control.
         */
        if (supports_hw_control(led_cdev)) {
                dev = led_cdev->hw_control_get_device(led_cdev);
                if (dev) {
                        const char *name = dev_name(dev);

                        trigger_data->hw_control = true;
                        set_device_name(trigger_data, name, strlen(name));

                        rc = led_cdev->hw_control_get(led_cdev, &mode);
                        if (!rc)
                                trigger_data->mode = mode;
                }
        }

        led_set_trigger_data(led_cdev, trigger_data);

        rc = register_netdevice_notifier(&trigger_data->notifier);
        if (rc)
                kfree(trigger_data);

        return rc;
}

static void netdev_trig_deactivate(struct led_classdev *led_cdev)
{
        struct led_netdev_data *trigger_data = led_get_trigger_data(led_cdev);

        unregister_netdevice_notifier(&trigger_data->notifier);

        cancel_delayed_work_sync(&trigger_data->work);

        dev_put(trigger_data->net_dev);

        kfree(trigger_data);
}

static struct led_trigger netdev_led_trigger = {
        .name = "netdev",
        .activate = netdev_trig_activate,
        .deactivate = netdev_trig_deactivate,
        .groups = netdev_trig_groups,
};

module_led_trigger(netdev_led_trigger);

MODULE_AUTHOR("Ben Whitten <ben.whitten@gmail.com>");
MODULE_AUTHOR("Oliver Jowett <oliver@opencloud.com>");
MODULE_DESCRIPTION("Netdev LED trigger");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("ledtrig:netdev");