/* * LED Kernel Timer Trigger * * 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/leds.h> #include "leds.h" struct timer_trig_data { int brightness_on; /* LED brightness during "on" period. * (LED_OFF < brightness_on <= LED_FULL) */ unsigned long delay_on; /* milliseconds on */ unsigned long delay_off; /* milliseconds off */ struct timer_list timer; }; static void led_timer_function(unsigned long data) { struct led_classdev *led_cdev = (struct led_classdev *) data; struct timer_trig_data *timer_data = led_cdev->trigger_data; unsigned long brightness; unsigned long delay; if (!timer_data->delay_on || !timer_data->delay_off) { led_set_brightness(led_cdev, LED_OFF); return; } brightness = led_get_brightness(led_cdev); if (!brightness) { /* Time to switch the LED on. */ brightness = timer_data->brightness_on; delay = timer_data->delay_on; } else { /* Store the current brightness value to be able * to restore it when the delay_off period is over. */ timer_data->brightness_on = brightness; brightness = LED_OFF; delay = timer_data->delay_off; } led_set_brightness(led_cdev, brightness); mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(delay)); } static ssize_t led_delay_on_show(struct device *dev, struct device_attribute *attr, char *buf) { struct led_classdev *led_cdev = dev_get_drvdata(dev); struct timer_trig_data *timer_data = led_cdev->trigger_data; return sprintf(buf, "%lu\n", timer_data->delay_on); } static ssize_t led_delay_on_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { struct led_classdev *led_cdev = dev_get_drvdata(dev); struct timer_trig_data *timer_data = led_cdev->trigger_data; int ret = -EINVAL; char *after; unsigned long state = simple_strtoul(buf, &after, 10); size_t count = after - buf; if (*after && isspace(*after)) count++; if (count == size) { if (timer_data->delay_on != state) { /* the new value differs from the previous */ timer_data->delay_on = state; /* deactivate previous settings */ del_timer_sync(&timer_data->timer); /* try to activate hardware acceleration, if any */ if (!led_cdev->blink_set || led_cdev->blink_set(led_cdev, &timer_data->delay_on, &timer_data->delay_off)) { /* no hardware acceleration, blink via timer */ mod_timer(&timer_data->timer, jiffies + 1); } } ret = count; } return ret; } static ssize_t led_delay_off_show(struct device *dev, struct device_attribute *attr, char *buf) { struct led_classdev *led_cdev = dev_get_drvdata(dev); struct timer_trig_data *timer_data = led_cdev->trigger_data; return sprintf(buf, "%lu\n", timer_data->delay_off); } static ssize_t led_delay_off_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t size) { struct led_classdev *led_cdev = dev_get_drvdata(dev); struct timer_trig_data *timer_data = led_cdev->trigger_data; int ret = -EINVAL; char *after; unsigned long state = simple_strtoul(buf, &after, 10); size_t count = after - buf; if (*after && isspace(*after)) count++; if (count == size) { if (timer_data->delay_off != state) { /* the new value differs from the previous */ timer_data->delay_off = state; /* deactivate previous settings */ del_timer_sync(&timer_data->timer); /* try to activate hardware acceleration, if any */ if (!led_cdev->blink_set || led_cdev->blink_set(led_cdev, &timer_data->delay_on, &timer_data->delay_off)) { /* no hardware acceleration, blink via timer */ mod_timer(&timer_data->timer, jiffies + 1); } } ret = count; } return ret; } static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store); static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store); static void timer_trig_activate(struct led_classdev *led_cdev) { struct timer_trig_data *timer_data; int rc; timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL); if (!timer_data) return; timer_data->brightness_on = led_get_brightness(led_cdev); if (timer_data->brightness_on == LED_OFF) timer_data->brightness_on = led_cdev->max_brightness; led_cdev->trigger_data = timer_data; init_timer(&timer_data->timer); timer_data->timer.function = led_timer_function; timer_data->timer.data = (unsigned long) led_cdev; rc = device_create_file(led_cdev->dev, &dev_attr_delay_on); if (rc) goto err_out; rc = device_create_file(led_cdev->dev, &dev_attr_delay_off); if (rc) goto err_out_delayon; /* If there is hardware support for blinking, start one * user friendly blink rate chosen by the driver. */ if (led_cdev->blink_set) led_cdev->blink_set(led_cdev, &timer_data->delay_on, &timer_data->delay_off); return; err_out_delayon: device_remove_file(led_cdev->dev, &dev_attr_delay_on); err_out: led_cdev->trigger_data = NULL; kfree(timer_data); } static void timer_trig_deactivate(struct led_classdev *led_cdev) { struct timer_trig_data *timer_data = led_cdev->trigger_data; unsigned long on = 0, off = 0; if (timer_data) { device_remove_file(led_cdev->dev, &dev_attr_delay_on); device_remove_file(led_cdev->dev, &dev_attr_delay_off); del_timer_sync(&timer_data->timer); kfree(timer_data); } /* If there is hardware support for blinking, stop it */ if (led_cdev->blink_set) led_cdev->blink_set(led_cdev, &on, &off); } static struct led_trigger timer_led_trigger = { .name = "timer", .activate = timer_trig_activate, .deactivate = timer_trig_deactivate, }; static int __init timer_trig_init(void) { return led_trigger_register(&timer_led_trigger); } static void __exit timer_trig_exit(void) { led_trigger_unregister(&timer_led_trigger); } module_init(timer_trig_init); module_exit(timer_trig_exit); MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>"); MODULE_DESCRIPTION("Timer LED trigger"); MODULE_LICENSE("GPL");