5ada28bf76
Currently, blinking LEDs can be awkward because it is not guaranteed that all LEDs implement blinking. The trigger that wants it to blink then needs to implement its own timer solution. Rather than require that, add led_blink_set() API that triggers can use. This function will attempt to use hw blinking, but if that fails implements a timer for it. To stop blinking again, brightness_set() also needs to be wrapped into API that will stop the software blink. As a result of this, the timer trigger becomes a very trivial one, and hopefully we can finally see triggers using blinking as well because it's always easy to use. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Acked-by: Richard Purdie <rpurdie@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
134 lines
3.1 KiB
C
134 lines
3.1 KiB
C
/*
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* LED Kernel Timer Trigger
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*
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* Copyright 2005-2006 Openedhand Ltd.
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*
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* Author: Richard Purdie <rpurdie@openedhand.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/device.h>
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#include <linux/ctype.h>
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#include <linux/leds.h>
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#include "leds.h"
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static ssize_t led_delay_on_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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return sprintf(buf, "%lu\n", led_cdev->blink_delay_on);
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}
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static ssize_t led_delay_on_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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int ret = -EINVAL;
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char *after;
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unsigned long state = simple_strtoul(buf, &after, 10);
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size_t count = after - buf;
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if (isspace(*after))
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count++;
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if (count == size) {
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led_blink_set(led_cdev, &state, &led_cdev->blink_delay_off);
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ret = count;
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}
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return ret;
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}
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static ssize_t led_delay_off_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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return sprintf(buf, "%lu\n", led_cdev->blink_delay_off);
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}
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static ssize_t led_delay_off_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct led_classdev *led_cdev = dev_get_drvdata(dev);
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int ret = -EINVAL;
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char *after;
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unsigned long state = simple_strtoul(buf, &after, 10);
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size_t count = after - buf;
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if (isspace(*after))
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count++;
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if (count == size) {
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led_blink_set(led_cdev, &led_cdev->blink_delay_on, &state);
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ret = count;
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}
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return ret;
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}
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static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
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static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
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static void timer_trig_activate(struct led_classdev *led_cdev)
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{
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int rc;
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led_cdev->trigger_data = NULL;
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rc = device_create_file(led_cdev->dev, &dev_attr_delay_on);
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if (rc)
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return;
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rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
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if (rc)
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goto err_out_delayon;
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led_cdev->trigger_data = (void *)1;
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return;
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err_out_delayon:
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device_remove_file(led_cdev->dev, &dev_attr_delay_on);
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}
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static void timer_trig_deactivate(struct led_classdev *led_cdev)
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{
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if (led_cdev->trigger_data) {
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device_remove_file(led_cdev->dev, &dev_attr_delay_on);
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device_remove_file(led_cdev->dev, &dev_attr_delay_off);
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}
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/* Stop blinking */
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led_brightness_set(led_cdev, LED_OFF);
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}
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static struct led_trigger timer_led_trigger = {
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.name = "timer",
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.activate = timer_trig_activate,
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.deactivate = timer_trig_deactivate,
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};
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static int __init timer_trig_init(void)
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{
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return led_trigger_register(&timer_led_trigger);
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}
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static void __exit timer_trig_exit(void)
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{
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led_trigger_unregister(&timer_led_trigger);
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}
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module_init(timer_trig_init);
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module_exit(timer_trig_exit);
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MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
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MODULE_DESCRIPTION("Timer LED trigger");
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MODULE_LICENSE("GPL");
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