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path: root/drivers/leds/trigger/ledtrig-transient.c
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Diffstat (limited to 'drivers/leds/trigger/ledtrig-transient.c')
-rw-r--r--drivers/leds/trigger/ledtrig-transient.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/drivers/leds/trigger/ledtrig-transient.c b/drivers/leds/trigger/ledtrig-transient.c
new file mode 100644
index 000000000..3c34de404
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-transient.c
@@ -0,0 +1,239 @@
+/*
+ * LED Kernel Transient Trigger
+ *
+ * Copyright (C) 2012 Shuah Khan <shuahkhan@gmail.com>
+ *
+ * Based on Richard Purdie's ledtrig-timer.c and Atsushi Nemoto's
+ * ledtrig-heartbeat.c
+ * Design and use-case input from Jonas Bonn <jonas@southpole.se> and
+ * Neil Brown <neilb@suse.de>
+ *
+ * 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.
+ *
+ */
+/*
+ * Transient trigger allows one shot timer activation. Please refer to
+ * Documentation/leds/ledtrig-transient.txt for details
+*/
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/leds.h>
+#include "../leds.h"
+
+struct transient_trig_data {
+ int activate;
+ int state;
+ int restore_state;
+ unsigned long duration;
+ struct timer_list timer;
+};
+
+static void transient_timer_function(unsigned long data)
+{
+ struct led_classdev *led_cdev = (struct led_classdev *) data;
+ struct transient_trig_data *transient_data = led_cdev->trigger_data;
+
+ transient_data->activate = 0;
+ led_set_brightness_async(led_cdev, transient_data->restore_state);
+}
+
+static ssize_t transient_activate_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct transient_trig_data *transient_data = led_cdev->trigger_data;
+
+ return sprintf(buf, "%d\n", transient_data->activate);
+}
+
+static ssize_t transient_activate_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct transient_trig_data *transient_data = led_cdev->trigger_data;
+ unsigned long state;
+ ssize_t ret;
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret)
+ return ret;
+
+ if (state != 1 && state != 0)
+ return -EINVAL;
+
+ /* cancel the running timer */
+ if (state == 0 && transient_data->activate == 1) {
+ del_timer(&transient_data->timer);
+ transient_data->activate = state;
+ led_set_brightness_async(led_cdev,
+ transient_data->restore_state);
+ return size;
+ }
+
+ /* start timer if there is no active timer */
+ if (state == 1 && transient_data->activate == 0 &&
+ transient_data->duration != 0) {
+ transient_data->activate = state;
+ led_set_brightness_async(led_cdev, transient_data->state);
+ transient_data->restore_state =
+ (transient_data->state == LED_FULL) ? LED_OFF : LED_FULL;
+ mod_timer(&transient_data->timer,
+ jiffies + transient_data->duration);
+ }
+
+ /* state == 0 && transient_data->activate == 0
+ timer is not active - just return */
+ /* state == 1 && transient_data->activate == 1
+ timer is already active - just return */
+
+ return size;
+}
+
+static ssize_t transient_duration_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct transient_trig_data *transient_data = led_cdev->trigger_data;
+
+ return sprintf(buf, "%lu\n", transient_data->duration);
+}
+
+static ssize_t transient_duration_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct transient_trig_data *transient_data = led_cdev->trigger_data;
+ unsigned long state;
+ ssize_t ret;
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret)
+ return ret;
+
+ transient_data->duration = state;
+ return size;
+}
+
+static ssize_t transient_state_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct transient_trig_data *transient_data = led_cdev->trigger_data;
+ int state;
+
+ state = (transient_data->state == LED_FULL) ? 1 : 0;
+ return sprintf(buf, "%d\n", state);
+}
+
+static ssize_t transient_state_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct transient_trig_data *transient_data = led_cdev->trigger_data;
+ unsigned long state;
+ ssize_t ret;
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret)
+ return ret;
+
+ if (state != 1 && state != 0)
+ return -EINVAL;
+
+ transient_data->state = (state == 1) ? LED_FULL : LED_OFF;
+ return size;
+}
+
+static DEVICE_ATTR(activate, 0644, transient_activate_show,
+ transient_activate_store);
+static DEVICE_ATTR(duration, 0644, transient_duration_show,
+ transient_duration_store);
+static DEVICE_ATTR(state, 0644, transient_state_show, transient_state_store);
+
+static void transient_trig_activate(struct led_classdev *led_cdev)
+{
+ int rc;
+ struct transient_trig_data *tdata;
+
+ tdata = kzalloc(sizeof(struct transient_trig_data), GFP_KERNEL);
+ if (!tdata) {
+ dev_err(led_cdev->dev,
+ "unable to allocate transient trigger\n");
+ return;
+ }
+ led_cdev->trigger_data = tdata;
+
+ rc = device_create_file(led_cdev->dev, &dev_attr_activate);
+ if (rc)
+ goto err_out;
+
+ rc = device_create_file(led_cdev->dev, &dev_attr_duration);
+ if (rc)
+ goto err_out_duration;
+
+ rc = device_create_file(led_cdev->dev, &dev_attr_state);
+ if (rc)
+ goto err_out_state;
+
+ setup_timer(&tdata->timer, transient_timer_function,
+ (unsigned long) led_cdev);
+ led_cdev->activated = true;
+
+ return;
+
+err_out_state:
+ device_remove_file(led_cdev->dev, &dev_attr_duration);
+err_out_duration:
+ device_remove_file(led_cdev->dev, &dev_attr_activate);
+err_out:
+ dev_err(led_cdev->dev, "unable to register transient trigger\n");
+ led_cdev->trigger_data = NULL;
+ kfree(tdata);
+}
+
+static void transient_trig_deactivate(struct led_classdev *led_cdev)
+{
+ struct transient_trig_data *transient_data = led_cdev->trigger_data;
+
+ if (led_cdev->activated) {
+ del_timer_sync(&transient_data->timer);
+ led_set_brightness_async(led_cdev,
+ transient_data->restore_state);
+ device_remove_file(led_cdev->dev, &dev_attr_activate);
+ device_remove_file(led_cdev->dev, &dev_attr_duration);
+ device_remove_file(led_cdev->dev, &dev_attr_state);
+ led_cdev->trigger_data = NULL;
+ led_cdev->activated = false;
+ kfree(transient_data);
+ }
+}
+
+static struct led_trigger transient_trigger = {
+ .name = "transient",
+ .activate = transient_trig_activate,
+ .deactivate = transient_trig_deactivate,
+};
+
+static int __init transient_trig_init(void)
+{
+ return led_trigger_register(&transient_trigger);
+}
+
+static void __exit transient_trig_exit(void)
+{
+ led_trigger_unregister(&transient_trigger);
+}
+
+module_init(transient_trig_init);
+module_exit(transient_trig_exit);
+
+MODULE_AUTHOR("Shuah Khan <shuahkhan@gmail.com>");
+MODULE_DESCRIPTION("Transient LED trigger");
+MODULE_LICENSE("GPL");