Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / leds / trigger / ledtrig-heartbeat.c

diff --git a/kernel/drivers/leds/trigger/ledtrig-heartbeat.c b/kernel/drivers/leds/trigger/ledtrig-heartbeat.c
new file mode 100644 (file)
index 0000000..fea6871
--- /dev/null
+++ b/kernel/drivers/leds/trigger/ledtrig-heartbeat.c
@@ -0,0 +1,161 @@
+/*
+ * LED Heartbeat Trigger
+ *
+ * Copyright (C) 2006 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
+ *
+ * Based on Richard Purdie's ledtrig-timer.c and some arch's
+ * CONFIG_HEARTBEAT code.
+ *
+ * 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/slab.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+#include <linux/leds.h>
+#include <linux/reboot.h>
+#include "../leds.h"
+
+static int panic_heartbeats;
+
+struct heartbeat_trig_data {
+       unsigned int phase;
+       unsigned int period;
+       struct timer_list timer;
+};
+
+static void led_heartbeat_function(unsigned long data)
+{
+       struct led_classdev *led_cdev = (struct led_classdev *) data;
+       struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
+       unsigned long brightness = LED_OFF;
+       unsigned long delay = 0;
+
+       if (unlikely(panic_heartbeats)) {
+               led_set_brightness(led_cdev, LED_OFF);
+               return;
+       }
+
+       /* acts like an actual heart beat -- ie thump-thump-pause... */
+       switch (heartbeat_data->phase) {
+       case 0:
+               /*
+                * The hyperbolic function below modifies the
+                * heartbeat period length in dependency of the
+                * current (1min) load. It goes through the points
+                * f(0)=1260, f(1)=860, f(5)=510, f(inf)->300.
+                */
+               heartbeat_data->period = 300 +
+                       (6720 << FSHIFT) / (5 * avenrun[0] + (7 << FSHIFT));
+               heartbeat_data->period =
+                       msecs_to_jiffies(heartbeat_data->period);
+               delay = msecs_to_jiffies(70);
+               heartbeat_data->phase++;
+               brightness = led_cdev->max_brightness;
+               break;
+       case 1:
+               delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
+               heartbeat_data->phase++;
+               break;
+       case 2:
+               delay = msecs_to_jiffies(70);
+               heartbeat_data->phase++;
+               brightness = led_cdev->max_brightness;
+               break;
+       default:
+               delay = heartbeat_data->period - heartbeat_data->period / 4 -
+                       msecs_to_jiffies(70);
+               heartbeat_data->phase = 0;
+               break;
+       }
+
+       led_set_brightness_async(led_cdev, brightness);
+       mod_timer(&heartbeat_data->timer, jiffies + delay);
+}
+
+static void heartbeat_trig_activate(struct led_classdev *led_cdev)
+{
+       struct heartbeat_trig_data *heartbeat_data;
+
+       heartbeat_data = kzalloc(sizeof(*heartbeat_data), GFP_KERNEL);
+       if (!heartbeat_data)
+               return;
+
+       led_cdev->trigger_data = heartbeat_data;
+       setup_timer(&heartbeat_data->timer,
+                   led_heartbeat_function, (unsigned long) led_cdev);
+       heartbeat_data->phase = 0;
+       led_heartbeat_function(heartbeat_data->timer.data);
+       led_cdev->activated = true;
+}
+
+static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
+{
+       struct heartbeat_trig_data *heartbeat_data = led_cdev->trigger_data;
+
+       if (led_cdev->activated) {
+               del_timer_sync(&heartbeat_data->timer);
+               kfree(heartbeat_data);
+               led_cdev->activated = false;
+       }
+}
+
+static struct led_trigger heartbeat_led_trigger = {
+       .name     = "heartbeat",
+       .activate = heartbeat_trig_activate,
+       .deactivate = heartbeat_trig_deactivate,
+};
+
+static int heartbeat_reboot_notifier(struct notifier_block *nb,
+                                    unsigned long code, void *unused)
+{
+       led_trigger_unregister(&heartbeat_led_trigger);
+       return NOTIFY_DONE;
+}
+
+static int heartbeat_panic_notifier(struct notifier_block *nb,
+                                    unsigned long code, void *unused)
+{
+       panic_heartbeats = 1;
+       return NOTIFY_DONE;
+}
+
+static struct notifier_block heartbeat_reboot_nb = {
+       .notifier_call = heartbeat_reboot_notifier,
+};
+
+static struct notifier_block heartbeat_panic_nb = {
+       .notifier_call = heartbeat_panic_notifier,
+};
+
+static int __init heartbeat_trig_init(void)
+{
+       int rc = led_trigger_register(&heartbeat_led_trigger);
+
+       if (!rc) {
+               atomic_notifier_chain_register(&panic_notifier_list,
+                                              &heartbeat_panic_nb);
+               register_reboot_notifier(&heartbeat_reboot_nb);
+       }
+       return rc;
+}
+
+static void __exit heartbeat_trig_exit(void)
+{
+       unregister_reboot_notifier(&heartbeat_reboot_nb);
+       atomic_notifier_chain_unregister(&panic_notifier_list,
+                                        &heartbeat_panic_nb);
+       led_trigger_unregister(&heartbeat_led_trigger);
+}
+
+module_init(heartbeat_trig_init);
+module_exit(heartbeat_trig_exit);
+
+MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
+MODULE_DESCRIPTION("Heartbeat LED trigger");
+MODULE_LICENSE("GPL");