diff options
| -rw-r--r-- | Documentation/leds/ledtrig-oneshot.txt | 59 | ||||
| -rw-r--r-- | drivers/leds/Kconfig | 14 | ||||
| -rw-r--r-- | drivers/leds/Makefile | 1 | ||||
| -rw-r--r-- | drivers/leds/ledtrig-oneshot.c | 204 |
4 files changed, 278 insertions, 0 deletions
diff --git a/Documentation/leds/ledtrig-oneshot.txt b/Documentation/leds/ledtrig-oneshot.txt new file mode 100644 index 00000000000..07cd1fa41a3 --- /dev/null +++ b/Documentation/leds/ledtrig-oneshot.txt @@ -0,0 +1,59 @@ +One-shot LED Trigger +==================== + +This is a LED trigger useful for signaling the user of an event where there are +no clear trap points to put standard led-on and led-off settings. Using this +trigger, the application needs only to signal the trigger when an event has +happened, than the trigger turns the LED on and than keeps it off for a +specified amount of time. + +This trigger is meant to be usable both for sporadic and dense events. In the +first case, the trigger produces a clear single controlled blink for each +event, while in the latter it keeps blinking at constant rate, as to signal +that the events are arriving continuously. + +A one-shot LED only stays in a constant state when there are no events. An +additional "invert" property specifies if the LED has to stay off (normal) or +on (inverted) when not rearmed. + +The trigger can be activated from user space on led class devices as shown +below: + + echo oneshot > trigger + +This adds the following sysfs attributes to the LED: + + delay_on - specifies for how many milliseconds the LED has to stay at + LED_FULL brightness after it has been armed. + Default to 100 ms. + + delay_off - specifies for how many milliseconds the LED has to stay at + LED_OFF brightness after it has been armed. + Default to 100 ms. + + invert - reverse the blink logic. If set to 0 (default) blink on for delay_on + ms, then blink off for delay_off ms, leaving the LED normally off. If + set to 1, blink off for delay_off ms, then blink on for delay_on ms, + leaving the LED normally on. + Setting this value also immediately change the LED state. + + shot - write any non-empty string to signal an events, this starts a blink + sequence if not already running. + +Example use-case: network devices, initialization: + + echo oneshot > trigger # set trigger for this led + echo 33 > delay_on # blink at 1 / (33 + 33) Hz on continuous traffic + echo 33 > delay_off + +interface goes up: + + echo 1 > invert # set led as normally-on, turn the led on + +packet received/transmitted: + + echo 1 > shot # led starts blinking, ignored if already blinking + +interface goes down + + echo 0 > invert # set led as normally-off, turn the led off diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig index 12b2b55c519..54dd1a396fa 100644 --- a/drivers/leds/Kconfig +++ b/drivers/leds/Kconfig @@ -443,6 +443,20 @@ config LEDS_TRIGGER_TIMER If unsure, say Y. +config LEDS_TRIGGER_ONESHOT + tristate "LED One-shot Trigger" + depends on LEDS_TRIGGERS + help + This allows LEDs to blink in one-shot pulses with parameters + controlled via sysfs. It's useful to notify the user on + sporadic events, when there are no clear begin and end trap points, + or on dense events, where this blinks the LED at constant rate if + rearmed continuously. + + It also shows how to use the led_blink_set_oneshot() function. + + If unsure, say Y. + config LEDS_TRIGGER_IDE_DISK bool "LED IDE Disk Trigger" depends on IDE_GD_ATA diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile index f8958cd6cf6..9112d518f9d 100644 --- a/drivers/leds/Makefile +++ b/drivers/leds/Makefile @@ -53,6 +53,7 @@ obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o # LED Triggers obj-$(CONFIG_LEDS_TRIGGER_TIMER) += ledtrig-timer.o +obj-$(CONFIG_LEDS_TRIGGER_ONESHOT) += ledtrig-oneshot.o obj-$(CONFIG_LEDS_TRIGGER_IDE_DISK) += ledtrig-ide-disk.o obj-$(CONFIG_LEDS_TRIGGER_HEARTBEAT) += ledtrig-heartbeat.o obj-$(CONFIG_LEDS_TRIGGER_BACKLIGHT) += ledtrig-backlight.o diff --git a/drivers/leds/ledtrig-oneshot.c b/drivers/leds/ledtrig-oneshot.c new file mode 100644 index 00000000000..5c9edf7f489 --- /dev/null +++ b/drivers/leds/ledtrig-oneshot.c @@ -0,0 +1,204 @@ +/* + * One-shot LED Trigger + * + * Copyright 2012, Fabio Baltieri <fabio.baltieri@gmail.com> + * + * Based on ledtrig-timer.c by 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/kernel.h> +#include <linux/init.h> +#include <linux/device.h> +#include <linux/ctype.h> +#include <linux/slab.h> +#include <linux/leds.h> +#include "leds.h" + +#define DEFAULT_DELAY 100 + +struct oneshot_trig_data { + unsigned int invert; +}; + +static ssize_t led_shot(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data; + + led_blink_set_oneshot(led_cdev, + &led_cdev->blink_delay_on, &led_cdev->blink_delay_off, + oneshot_data->invert); + + /* content is ignored */ + return size; +} +static ssize_t led_invert_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data; + + return sprintf(buf, "%u\n", oneshot_data->invert); +} + +static ssize_t led_invert_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t size) +{ + struct led_classdev *led_cdev = dev_get_drvdata(dev); + struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data; + unsigned long state; + int ret; + + ret = kstrtoul(buf, 0, &state); + if (ret) + return ret; + + oneshot_data->invert = !!state; + + if (oneshot_data->invert) + led_set_brightness(led_cdev, LED_FULL); + else + led_set_brightness(led_cdev, LED_OFF); + + return size; +} + +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); + + return sprintf(buf, "%lu\n", led_cdev->blink_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); + unsigned long state; + int ret; + + ret = kstrtoul(buf, 0, &state); + if (ret) + return ret; + + led_cdev->blink_delay_on = state; + + return size; +} +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); + + return sprintf(buf, "%lu\n", led_cdev->blink_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); + unsigned long state; + int ret; + + ret = kstrtoul(buf, 0, &state); + if (ret) + return ret; + + led_cdev->blink_delay_off = state; + + return size; +} + +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 DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store); +static DEVICE_ATTR(shot, 0200, NULL, led_shot); + +static void oneshot_trig_activate(struct led_classdev *led_cdev) +{ + struct oneshot_trig_data *oneshot_data; + int rc; + + oneshot_data = kzalloc(sizeof(*oneshot_data), GFP_KERNEL); + if (!oneshot_data) + return; + + led_cdev->trigger_data = oneshot_data; + + rc = device_create_file(led_cdev->dev, &dev_attr_delay_on); + if (rc) + goto err_out_trig_data; + rc = device_create_file(led_cdev->dev, &dev_attr_delay_off); + if (rc) + goto err_out_delayon; + rc = device_create_file(led_cdev->dev, &dev_attr_invert); + if (rc) + goto err_out_delayoff; + rc = device_create_file(led_cdev->dev, &dev_attr_shot); + if (rc) + goto err_out_invert; + + led_cdev->blink_delay_on = DEFAULT_DELAY; + led_cdev->blink_delay_off = DEFAULT_DELAY; + + led_cdev->activated = true; + + return; + +err_out_invert: + device_remove_file(led_cdev->dev, &dev_attr_invert); +err_out_delayoff: + device_remove_file(led_cdev->dev, &dev_attr_delay_off); +err_out_delayon: + device_remove_file(led_cdev->dev, &dev_attr_delay_on); +err_out_trig_data: + kfree(led_cdev->trigger_data); +} + +static void oneshot_trig_deactivate(struct led_classdev *led_cdev) +{ + struct oneshot_trig_data *oneshot_data = led_cdev->trigger_data; + + if (led_cdev->activated) { + device_remove_file(led_cdev->dev, &dev_attr_delay_on); + device_remove_file(led_cdev->dev, &dev_attr_delay_off); + device_remove_file(led_cdev->dev, &dev_attr_invert); + device_remove_file(led_cdev->dev, &dev_attr_shot); + kfree(oneshot_data); + led_cdev->activated = false; + } + + /* Stop blinking */ + led_brightness_set(led_cdev, LED_OFF); +} + +static struct led_trigger oneshot_led_trigger = { + .name = "oneshot", + .activate = oneshot_trig_activate, + .deactivate = oneshot_trig_deactivate, +}; + +static int __init oneshot_trig_init(void) +{ + return led_trigger_register(&oneshot_led_trigger); +} + +static void __exit oneshot_trig_exit(void) +{ + led_trigger_unregister(&oneshot_led_trigger); +} + +module_init(oneshot_trig_init); +module_exit(oneshot_trig_exit); + +MODULE_AUTHOR("Fabio Baltieri <fabio.baltieri@gmail.com>"); +MODULE_DESCRIPTION("One-shot LED trigger"); +MODULE_LICENSE("GPL"); |