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-rw-r--r--drivers/leds/trigger/ledtrig-heartbeat.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/leds/trigger/ledtrig-heartbeat.c b/drivers/leds/trigger/ledtrig-heartbeat.c
new file mode 100644
index 000000000..7fe0a0557
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-heartbeat.c
@@ -0,0 +1,213 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/panic_notifier.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include <linux/sched.h>
+#include <linux/sched/loadavg.h>
+#include <linux/leds.h>
+#include <linux/reboot.h>
+#include "../leds.h"
+
+static int panic_heartbeats;
+
+struct heartbeat_trig_data {
+ struct led_classdev *led_cdev;
+ unsigned int phase;
+ unsigned int period;
+ struct timer_list timer;
+ unsigned int invert;
+};
+
+static void led_heartbeat_function(struct timer_list *t)
+{
+ struct heartbeat_trig_data *heartbeat_data =
+ from_timer(heartbeat_data, t, timer);
+ struct led_classdev *led_cdev;
+ unsigned long brightness = LED_OFF;
+ unsigned long delay = 0;
+
+ led_cdev = heartbeat_data->led_cdev;
+
+ if (unlikely(panic_heartbeats)) {
+ led_set_brightness_nosleep(led_cdev, LED_OFF);
+ return;
+ }
+
+ if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags))
+ led_cdev->blink_brightness = led_cdev->new_blink_brightness;
+
+ /* 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++;
+ if (!heartbeat_data->invert)
+ brightness = led_cdev->blink_brightness;
+ break;
+ case 1:
+ delay = heartbeat_data->period / 4 - msecs_to_jiffies(70);
+ heartbeat_data->phase++;
+ if (heartbeat_data->invert)
+ brightness = led_cdev->blink_brightness;
+ break;
+ case 2:
+ delay = msecs_to_jiffies(70);
+ heartbeat_data->phase++;
+ if (!heartbeat_data->invert)
+ brightness = led_cdev->blink_brightness;
+ break;
+ default:
+ delay = heartbeat_data->period - heartbeat_data->period / 4 -
+ msecs_to_jiffies(70);
+ heartbeat_data->phase = 0;
+ if (heartbeat_data->invert)
+ brightness = led_cdev->blink_brightness;
+ break;
+ }
+
+ led_set_brightness_nosleep(led_cdev, brightness);
+ mod_timer(&heartbeat_data->timer, jiffies + delay);
+}
+
+static ssize_t led_invert_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct heartbeat_trig_data *heartbeat_data =
+ led_trigger_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", heartbeat_data->invert);
+}
+
+static ssize_t led_invert_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct heartbeat_trig_data *heartbeat_data =
+ led_trigger_get_drvdata(dev);
+ unsigned long state;
+ int ret;
+
+ ret = kstrtoul(buf, 0, &state);
+ if (ret)
+ return ret;
+
+ heartbeat_data->invert = !!state;
+
+ return size;
+}
+
+static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
+
+static struct attribute *heartbeat_trig_attrs[] = {
+ &dev_attr_invert.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(heartbeat_trig);
+
+static int 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 -ENOMEM;
+
+ led_set_trigger_data(led_cdev, heartbeat_data);
+ heartbeat_data->led_cdev = led_cdev;
+
+ timer_setup(&heartbeat_data->timer, led_heartbeat_function, 0);
+ heartbeat_data->phase = 0;
+ if (!led_cdev->blink_brightness)
+ led_cdev->blink_brightness = led_cdev->max_brightness;
+ led_heartbeat_function(&heartbeat_data->timer);
+ set_bit(LED_BLINK_SW, &led_cdev->work_flags);
+
+ return 0;
+}
+
+static void heartbeat_trig_deactivate(struct led_classdev *led_cdev)
+{
+ struct heartbeat_trig_data *heartbeat_data =
+ led_get_trigger_data(led_cdev);
+
+ del_timer_sync(&heartbeat_data->timer);
+ kfree(heartbeat_data);
+ clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
+}
+
+static struct led_trigger heartbeat_led_trigger = {
+ .name = "heartbeat",
+ .activate = heartbeat_trig_activate,
+ .deactivate = heartbeat_trig_deactivate,
+ .groups = heartbeat_trig_groups,
+};
+
+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 v2");