X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fleds%2Ftrigger%2Fledtrig-heartbeat.c;fp=kernel%2Fdrivers%2Fleds%2Ftrigger%2Fledtrig-heartbeat.c;h=fea6871d2609d405d9f0d0046059a7562bb8152f;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git

diff --git a/kernel/drivers/leds/trigger/ledtrig-heartbeat.c b/kernel/drivers/leds/trigger/ledtrig-heartbeat.c
new file mode 100644
index 000000000..fea6871d2
--- /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");