--- /dev/null
+/*
+ * LED USB device Trigger
+ *
+ * Toggles the LED to reflect the presence and activity of an USB device
+ * Copyright (C) Gabor Juhos <juhosg@openwrt.org>
+ *
+ * derived from ledtrig-netdev.c:
+ * Copyright 2007 Oliver Jowett <oliver@opencloud.com>
+ *
+ * ledtrig-netdev.c derived from ledtrig-timer.c:
+ * Copyright 2005-2006 Openedhand Ltd.
+ * Author: Richard Purdie <rpurdie@openedhand.com>
+ *
+ * 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/timer.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/leds.h>
+#include <linux/usb.h>
+
+#include "leds.h"
+
+#define DEV_BUS_ID_SIZE 32
+
+/*
+ * Configurable sysfs attributes:
+ *
+ * device_name - name of the USB device to monitor
+ * activity_interval - duration of LED blink, in milliseconds
+ */
+
+struct usbdev_trig_data {
+ rwlock_t lock;
+
+ struct timer_list timer;
+ struct notifier_block notifier;
+
+ struct led_classdev *led_cdev;
+ struct usb_device *usb_dev;
+
+ char device_name[DEV_BUS_ID_SIZE];
+ unsigned interval;
+ int last_urbnum;
+};
+
+static void usbdev_trig_update_state(struct usbdev_trig_data *td)
+{
+ if (td->usb_dev)
+ led_set_brightness(td->led_cdev, LED_FULL);
+ else
+ led_set_brightness(td->led_cdev, LED_OFF);
+
+ if (td->interval && td->usb_dev)
+ mod_timer(&td->timer, jiffies + td->interval);
+ else
+ del_timer(&td->timer);
+}
+
+static ssize_t usbdev_trig_name_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct usbdev_trig_data *td = led_cdev->trigger_data;
+
+ read_lock(&td->lock);
+ sprintf(buf, "%s\n", td->device_name);
+ read_unlock(&td->lock);
+
+ return strlen(buf) + 1;
+}
+
+static ssize_t usbdev_trig_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 usbdev_trig_data *td = led_cdev->trigger_data;
+
+ if (size < 0 || size >= DEV_BUS_ID_SIZE)
+ return -EINVAL;
+
+ write_lock(&td->lock);
+
+ strcpy(td->device_name, buf);
+ if (size > 0 && td->device_name[size - 1] == '\n')
+ td->device_name[size - 1] = 0;
+
+ if (td->device_name[0] != 0) {
+ struct usb_device *usb_dev;
+
+ /* check for existing device to update from */
+ usb_dev = usb_find_device_by_name(td->device_name);
+ if (usb_dev) {
+ if (td->usb_dev)
+ usb_put_dev(td->usb_dev);
+
+ td->usb_dev = usb_dev;
+ td->last_urbnum = atomic_read(&usb_dev->urbnum);
+ }
+
+ /* updates LEDs, may start timers */
+ usbdev_trig_update_state(td);
+ }
+
+ write_unlock(&td->lock);
+ return size;
+}
+
+static DEVICE_ATTR(device_name, 0644, usbdev_trig_name_show,
+ usbdev_trig_name_store);
+
+static ssize_t usbdev_trig_interval_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct usbdev_trig_data *td = led_cdev->trigger_data;
+
+ read_lock(&td->lock);
+ sprintf(buf, "%u\n", jiffies_to_msecs(td->interval));
+ read_unlock(&td->lock);
+
+ return strlen(buf) + 1;
+}
+
+static ssize_t usbdev_trig_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 usbdev_trig_data *td = 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++;
+
+ if (count == size && value <= 10000) {
+ write_lock(&td->lock);
+ td->interval = msecs_to_jiffies(value);
+ usbdev_trig_update_state(td); /* resets timer */
+ write_unlock(&td->lock);
+ ret = count;
+ }
+
+ return ret;
+}
+
+static DEVICE_ATTR(activity_interval, 0644, usbdev_trig_interval_show,
+ usbdev_trig_interval_store);
+
+static int usbdev_trig_notify(struct notifier_block *nb,
+ unsigned long evt,
+ void *data)
+{
+ struct usb_device *usb_dev;
+ struct usbdev_trig_data *td;
+
+ if (evt != USB_DEVICE_ADD && evt != USB_DEVICE_REMOVE)
+ return NOTIFY_DONE;
+
+ usb_dev = data;
+ td = container_of(nb, struct usbdev_trig_data, notifier);
+
+ write_lock(&td->lock);
+
+ if (strcmp(dev_name(&usb_dev->dev), td->device_name))
+ goto done;
+
+ if (evt == USB_DEVICE_ADD) {
+ usb_get_dev(usb_dev);
+ if (td->usb_dev != NULL)
+ usb_put_dev(td->usb_dev);
+ td->usb_dev = usb_dev;
+ td->last_urbnum = atomic_read(&usb_dev->urbnum);
+ } else if (evt == USB_DEVICE_REMOVE) {
+ if (td->usb_dev != NULL) {
+ usb_put_dev(td->usb_dev);
+ td->usb_dev = NULL;
+ }
+ }
+
+ usbdev_trig_update_state(td);
+
+done:
+ write_unlock(&td->lock);
+ return NOTIFY_DONE;
+}
+
+/* here's the real work! */
+static void usbdev_trig_timer(unsigned long arg)
+{
+ struct usbdev_trig_data *td = (struct usbdev_trig_data *)arg;
+ int new_urbnum;
+
+ write_lock(&td->lock);
+
+ if (!td->usb_dev || td->interval == 0) {
+ /*
+ * we don't need to do timer work, just reflect device presence
+ */
+ if (td->usb_dev)
+ led_set_brightness(td->led_cdev, LED_FULL);
+ else
+ led_set_brightness(td->led_cdev, LED_OFF);
+
+ goto no_restart;
+ }
+
+ if (td->interval)
+ new_urbnum = atomic_read(&td->usb_dev->urbnum);
+ else
+ new_urbnum = 0;
+
+ if (td->usb_dev) {
+ /*
+ * Base state is ON (device is present). If there's no device,
+ * we don't get this far and the LED is off.
+ * OFF -> ON always
+ * ON -> OFF on activity
+ */
+ if (td->led_cdev->brightness == LED_OFF)
+ led_set_brightness(td->led_cdev, LED_FULL);
+ else if (td->last_urbnum != new_urbnum)
+ led_set_brightness(td->led_cdev, LED_OFF);
+ } else {
+ /*
+ * base state is OFF
+ * ON -> OFF always
+ * OFF -> ON on activity
+ */
+ if (td->led_cdev->brightness == LED_FULL)
+ led_set_brightness(td->led_cdev, LED_OFF);
+ else if (td->last_urbnum != new_urbnum)
+ led_set_brightness(td->led_cdev, LED_FULL);
+ }
+
+ td->last_urbnum = new_urbnum;
+ mod_timer(&td->timer, jiffies + td->interval);
+
+no_restart:
+ write_unlock(&td->lock);
+}
+
+static void usbdev_trig_activate(struct led_classdev *led_cdev)
+{
+ struct usbdev_trig_data *td;
+ int rc;
+
+ td = kzalloc(sizeof(struct usbdev_trig_data), GFP_KERNEL);
+ if (!td)
+ return;
+
+ rwlock_init(&td->lock);
+
+ td->notifier.notifier_call = usbdev_trig_notify;
+ td->notifier.priority = 10;
+
+ setup_timer(&td->timer, usbdev_trig_timer, (unsigned long) td);
+
+ td->led_cdev = led_cdev;
+ td->interval = msecs_to_jiffies(50);
+
+ led_cdev->trigger_data = td;
+
+ 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_activity_interval);
+ if (rc)
+ goto err_out_device_name;
+
+ usb_register_notify(&td->notifier);
+ return;
+
+err_out_device_name:
+ device_remove_file(led_cdev->dev, &dev_attr_device_name);
+err_out:
+ led_cdev->trigger_data = NULL;
+ kfree(td);
+}
+
+static void usbdev_trig_deactivate(struct led_classdev *led_cdev)
+{
+ struct usbdev_trig_data *td = led_cdev->trigger_data;
+
+ if (td) {
+ usb_unregister_notify(&td->notifier);
+
+ device_remove_file(led_cdev->dev, &dev_attr_device_name);
+ device_remove_file(led_cdev->dev, &dev_attr_activity_interval);
+
+ write_lock(&td->lock);
+
+ if (td->usb_dev) {
+ usb_put_dev(td->usb_dev);
+ td->usb_dev = NULL;
+ }
+
+ write_unlock(&td->lock);
+
+ del_timer_sync(&td->timer);
+
+ kfree(td);
+ }
+}
+
+static struct led_trigger usbdev_led_trigger = {
+ .name = "usbdev",
+ .activate = usbdev_trig_activate,
+ .deactivate = usbdev_trig_deactivate,
+};
+
+static int __init usbdev_trig_init(void)
+{
+ return led_trigger_register(&usbdev_led_trigger);
+}
+
+static void __exit usbdev_trig_exit(void)
+{
+ led_trigger_unregister(&usbdev_led_trigger);
+}
+
+module_init(usbdev_trig_init);
+module_exit(usbdev_trig_exit);
+
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_DESCRIPTION("USB device LED trigger");
+MODULE_LICENSE("GPL v2");
projects / openwrt.git / commitdiff