Initial import

1 files changed, 342 insertions, 0 deletions

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
new file mode 100644
index 000000000..e8b1120f4
--- /dev/null
+++ b/drivers/leds/led-triggers.c
@@ -0,0 +1,342 @@
+/*
+ * LED Triggers Core
+ *
+ * Copyright 2005-2007 Openedhand Ltd.
+ *
+ * Author: 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/list.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/timer.h>
+#include <linux/rwsem.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
+#include "leds.h"
+
+/*
+ * Nests outside led_cdev->trigger_lock
+ */
+static DECLARE_RWSEM(triggers_list_lock);
+static LIST_HEAD(trigger_list);
+
+ /* Used by LED Class */
+
+ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
+		const char *buf, size_t count)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	char trigger_name[TRIG_NAME_MAX];
+	struct led_trigger *trig;
+	size_t len;
+	int ret = count;
+
+	mutex_lock(&led_cdev->led_access);
+
+	if (led_sysfs_is_disabled(led_cdev)) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	trigger_name[sizeof(trigger_name) - 1] = '\0';
+	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
+	len = strlen(trigger_name);
+
+	if (len && trigger_name[len - 1] == '\n')
+		trigger_name[len - 1] = '\0';
+
+	if (!strcmp(trigger_name, "none")) {
+		led_trigger_remove(led_cdev);
+		goto unlock;
+	}
+
+	down_read(&triggers_list_lock);
+	list_for_each_entry(trig, &trigger_list, next_trig) {
+		if (!strcmp(trigger_name, trig->name)) {
+			down_write(&led_cdev->trigger_lock);
+			led_trigger_set(led_cdev, trig);
+			up_write(&led_cdev->trigger_lock);
+
+			up_read(&triggers_list_lock);
+			goto unlock;
+		}
+	}
+	up_read(&triggers_list_lock);
+
+unlock:
+	mutex_unlock(&led_cdev->led_access);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(led_trigger_store);
+
+ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
+		char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	struct led_trigger *trig;
+	int len = 0;
+
+	down_read(&triggers_list_lock);
+	down_read(&led_cdev->trigger_lock);
+
+	if (!led_cdev->trigger)
+		len += sprintf(buf+len, "[none] ");
+	else
+		len += sprintf(buf+len, "none ");
+
+	list_for_each_entry(trig, &trigger_list, next_trig) {
+		if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
+							trig->name))
+			len += sprintf(buf+len, "[%s] ", trig->name);
+		else
+			len += sprintf(buf+len, "%s ", trig->name);
+	}
+	up_read(&led_cdev->trigger_lock);
+	up_read(&triggers_list_lock);
+
+	len += sprintf(len+buf, "\n");
+	return len;
+}
+EXPORT_SYMBOL_GPL(led_trigger_show);
+
+/* Caller must ensure led_cdev->trigger_lock held */
+void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
+{
+	unsigned long flags;
+	char *event = NULL;
+	char *envp[2];
+	const char *name;
+
+	name = trig ? trig->name : "none";
+	event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
+
+	/* Remove any existing trigger */
+	if (led_cdev->trigger) {
+		write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
+		list_del(&led_cdev->trig_list);
+		write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
+			flags);
+		cancel_work_sync(&led_cdev->set_brightness_work);
+		led_stop_software_blink(led_cdev);
+		if (led_cdev->trigger->deactivate)
+			led_cdev->trigger->deactivate(led_cdev);
+		led_cdev->trigger = NULL;
+		led_set_brightness(led_cdev, LED_OFF);
+	}
+	if (trig) {
+		write_lock_irqsave(&trig->leddev_list_lock, flags);
+		list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
+		write_unlock_irqrestore(&trig->leddev_list_lock, flags);
+		led_cdev->trigger = trig;
+		if (trig->activate)
+			trig->activate(led_cdev);
+	}
+
+	if (event) {
+		envp[0] = event;
+		envp[1] = NULL;
+		kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp);
+		kfree(event);
+	}
+}
+EXPORT_SYMBOL_GPL(led_trigger_set);
+
+void led_trigger_remove(struct led_classdev *led_cdev)
+{
+	down_write(&led_cdev->trigger_lock);
+	led_trigger_set(led_cdev, NULL);
+	up_write(&led_cdev->trigger_lock);
+}
+EXPORT_SYMBOL_GPL(led_trigger_remove);
+
+void led_trigger_set_default(struct led_classdev *led_cdev)
+{
+	struct led_trigger *trig;
+
+	if (!led_cdev->default_trigger)
+		return;
+
+	down_read(&triggers_list_lock);
+	down_write(&led_cdev->trigger_lock);
+	list_for_each_entry(trig, &trigger_list, next_trig) {
+		if (!strcmp(led_cdev->default_trigger, trig->name))
+			led_trigger_set(led_cdev, trig);
+	}
+	up_write(&led_cdev->trigger_lock);
+	up_read(&triggers_list_lock);
+}
+EXPORT_SYMBOL_GPL(led_trigger_set_default);
+
+void led_trigger_rename_static(const char *name, struct led_trigger *trig)
+{
+	/* new name must be on a temporary string to prevent races */
+	BUG_ON(name == trig->name);
+
+	down_write(&triggers_list_lock);
+	/* this assumes that trig->name was originaly allocated to
+	 * non constant storage */
+	strcpy((char *)trig->name, name);
+	up_write(&triggers_list_lock);
+}
+EXPORT_SYMBOL_GPL(led_trigger_rename_static);
+
+/* LED Trigger Interface */
+
+int led_trigger_register(struct led_trigger *trig)
+{
+	struct led_classdev *led_cdev;
+	struct led_trigger *_trig;
+
+	rwlock_init(&trig->leddev_list_lock);
+	INIT_LIST_HEAD(&trig->led_cdevs);
+
+	down_write(&triggers_list_lock);
+	/* Make sure the trigger's name isn't already in use */
+	list_for_each_entry(_trig, &trigger_list, next_trig) {
+		if (!strcmp(_trig->name, trig->name)) {
+			up_write(&triggers_list_lock);
+			return -EEXIST;
+		}
+	}
+	/* Add to the list of led triggers */
+	list_add_tail(&trig->next_trig, &trigger_list);
+	up_write(&triggers_list_lock);
+
+	/* Register with any LEDs that have this as a default trigger */
+	down_read(&leds_list_lock);
+	list_for_each_entry(led_cdev, &leds_list, node) {
+		down_write(&led_cdev->trigger_lock);
+		if (!led_cdev->trigger && led_cdev->default_trigger &&
+			    !strcmp(led_cdev->default_trigger, trig->name))
+			led_trigger_set(led_cdev, trig);
+		up_write(&led_cdev->trigger_lock);
+	}
+	up_read(&leds_list_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(led_trigger_register);
+
+void led_trigger_unregister(struct led_trigger *trig)
+{
+	struct led_classdev *led_cdev;
+
+	if (list_empty_careful(&trig->next_trig))
+		return;
+
+	/* Remove from the list of led triggers */
+	down_write(&triggers_list_lock);
+	list_del_init(&trig->next_trig);
+	up_write(&triggers_list_lock);
+
+	/* Remove anyone actively using this trigger */
+	down_read(&leds_list_lock);
+	list_for_each_entry(led_cdev, &leds_list, node) {
+		down_write(&led_cdev->trigger_lock);
+		if (led_cdev->trigger == trig)
+			led_trigger_set(led_cdev, NULL);
+		up_write(&led_cdev->trigger_lock);
+	}
+	up_read(&leds_list_lock);
+}
+EXPORT_SYMBOL_GPL(led_trigger_unregister);
+
+/* Simple LED Tigger Interface */
+
+void led_trigger_event(struct led_trigger *trig,
+			enum led_brightness brightness)
+{
+	struct led_classdev *led_cdev;
+
+	if (!trig)
+		return;
+
+	read_lock(&trig->leddev_list_lock);
+	list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list)
+		led_set_brightness(led_cdev, brightness);
+	read_unlock(&trig->leddev_list_lock);
+}
+EXPORT_SYMBOL_GPL(led_trigger_event);
+
+static void led_trigger_blink_setup(struct led_trigger *trig,
+			     unsigned long *delay_on,
+			     unsigned long *delay_off,
+			     int oneshot,
+			     int invert)
+{
+	struct led_classdev *led_cdev;
+
+	if (!trig)
+		return;
+
+	read_lock(&trig->leddev_list_lock);
+	list_for_each_entry(led_cdev, &trig->led_cdevs, trig_list) {
+		if (oneshot)
+			led_blink_set_oneshot(led_cdev, delay_on, delay_off,
+					      invert);
+		else
+			led_blink_set(led_cdev, delay_on, delay_off);
+	}
+	read_unlock(&trig->leddev_list_lock);
+}
+
+void led_trigger_blink(struct led_trigger *trig,
+		       unsigned long *delay_on,
+		       unsigned long *delay_off)
+{
+	led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
+}
+EXPORT_SYMBOL_GPL(led_trigger_blink);
+
+void led_trigger_blink_oneshot(struct led_trigger *trig,
+			       unsigned long *delay_on,
+			       unsigned long *delay_off,
+			       int invert)
+{
+	led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
+}
+EXPORT_SYMBOL_GPL(led_trigger_blink_oneshot);
+
+void led_trigger_register_simple(const char *name, struct led_trigger **tp)
+{
+	struct led_trigger *trig;
+	int err;
+
+	trig = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
+
+	if (trig) {
+		trig->name = name;
+		err = led_trigger_register(trig);
+		if (err < 0) {
+			kfree(trig);
+			trig = NULL;
+			pr_warn("LED trigger %s failed to register (%d)\n",
+				name, err);
+		}
+	} else {
+		pr_warn("LED trigger %s failed to register (no memory)\n",
+			name);
+	}
+	*tp = trig;
+}
+EXPORT_SYMBOL_GPL(led_trigger_register_simple);
+
+void led_trigger_unregister_simple(struct led_trigger *trig)
+{
+	if (trig)
+		led_trigger_unregister(trig);
+	kfree(trig);
+}
+EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
+
+MODULE_AUTHOR("Richard Purdie");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LED Triggers Core");