diff options
Diffstat (limited to 'drivers/leds/ledtrig-timer.c')
| -rw-r--r-- | drivers/leds/ledtrig-timer.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/drivers/leds/ledtrig-timer.c b/drivers/leds/ledtrig-timer.c new file mode 100644 index 0000000..db68196 --- /dev/null +++ b/drivers/leds/ledtrig-timer.c @@ -0,0 +1,232 @@ +/* + * 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_FULL; + 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; + + 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); + } +} + +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"); |
