1 files changed, 239 insertions, 0 deletions

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
new file mode 100644
index 000000000000..5e2cd8be1191
--- /dev/null
+++ b/drivers/leds/led-triggers.c
@@ -0,0 +1,239 @@
+/*
+ * LED Triggers Core
+ *
+ * Copyright 2005-2006 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/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/sysdev.h>
+#include <linux/timer.h>
+#include <linux/leds.h>
+#include "leds.h"
+
+/*
+ * Nests outside led_cdev->trigger_lock
+ */
+static rwlock_t triggers_list_lock = RW_LOCK_UNLOCKED;
+static LIST_HEAD(trigger_list);
+
+ssize_t led_trigger_store(struct class_device *dev, const char *buf,
+                        size_t count)
+{
+        struct led_classdev *led_cdev = class_get_devdata(dev);
+        char trigger_name[TRIG_NAME_MAX];
+        struct led_trigger *trig;
+        size_t len;
+
+        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")) {
+                write_lock(&led_cdev->trigger_lock);
+                led_trigger_set(led_cdev, NULL);
+                write_unlock(&led_cdev->trigger_lock);
+                return count;
+        }
+
+        read_lock(&triggers_list_lock);
+        list_for_each_entry(trig, &trigger_list, next_trig) {
+                if (!strcmp(trigger_name, trig->name)) {
+                        write_lock(&led_cdev->trigger_lock);
+                        led_trigger_set(led_cdev, trig);
+                        write_unlock(&led_cdev->trigger_lock);
+
+                        read_unlock(&triggers_list_lock);
+                        return count;
+                }
+        }
+        read_unlock(&triggers_list_lock);
+
+        return -EINVAL;
+}
+
+
+ssize_t led_trigger_show(struct class_device *dev, char *buf)
+{
+        struct led_classdev *led_cdev = class_get_devdata(dev);
+        struct led_trigger *trig;
+        int len = 0;
+
+        read_lock(&triggers_list_lock);
+        read_lock(&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);
+        }
+        read_unlock(&led_cdev->trigger_lock);
+        read_unlock(&triggers_list_lock);
+
+        len += sprintf(len+buf, "\n");
+        return len;
+}
+
+void led_trigger_event(struct led_trigger *trigger,
+                        enum led_brightness brightness)
+{
+        struct list_head *entry;
+
+        if (!trigger)
+                return;
+
+        read_lock(&trigger->leddev_list_lock);
+        list_for_each(entry, &trigger->led_cdevs) {
+                struct led_classdev *led_cdev;
+
+                led_cdev = list_entry(entry, struct led_classdev, trig_list);
+                led_set_brightness(led_cdev, brightness);
+        }
+        read_unlock(&trigger->leddev_list_lock);
+}
+
+/* Caller must ensure led_cdev->trigger_lock held */
+void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger)
+{
+        unsigned long flags;
+
+        /* 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);
+                if (led_cdev->trigger->deactivate)
+                        led_cdev->trigger->deactivate(led_cdev);
+        }
+        if (trigger) {
+                write_lock_irqsave(&trigger->leddev_list_lock, flags);
+                list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs);
+                write_unlock_irqrestore(&trigger->leddev_list_lock, flags);
+                if (trigger->activate)
+                        trigger->activate(led_cdev);
+        }
+        led_cdev->trigger = trigger;
+}
+
+void led_trigger_set_default(struct led_classdev *led_cdev)
+{
+        struct led_trigger *trig;
+
+        if (!led_cdev->default_trigger)
+                return;
+
+        read_lock(&triggers_list_lock);
+        write_lock(&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);
+        }
+        write_unlock(&led_cdev->trigger_lock);
+        read_unlock(&triggers_list_lock);
+}
+
+int led_trigger_register(struct led_trigger *trigger)
+{
+        struct led_classdev *led_cdev;
+
+        rwlock_init(&trigger->leddev_list_lock);
+        INIT_LIST_HEAD(&trigger->led_cdevs);
+
+        /* Add to the list of led triggers */
+        write_lock(&triggers_list_lock);
+        list_add_tail(&trigger->next_trig, &trigger_list);
+        write_unlock(&triggers_list_lock);
+
+        /* Register with any LEDs that have this as a default trigger */
+        read_lock(&leds_list_lock);
+        list_for_each_entry(led_cdev, &leds_list, node) {
+                write_lock(&led_cdev->trigger_lock);
+                if (!led_cdev->trigger && led_cdev->default_trigger &&
+                            !strcmp(led_cdev->default_trigger, trigger->name))
+                        led_trigger_set(led_cdev, trigger);
+                write_unlock(&led_cdev->trigger_lock);
+        }
+        read_unlock(&leds_list_lock);
+
+        return 0;
+}
+
+void led_trigger_register_simple(const char *name, struct led_trigger **tp)
+{
+        struct led_trigger *trigger;
+
+        trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL);
+
+        if (trigger) {
+                trigger->name = name;
+                led_trigger_register(trigger);
+        }
+        *tp = trigger;
+}
+
+void led_trigger_unregister(struct led_trigger *trigger)
+{
+        struct led_classdev *led_cdev;
+
+        /* Remove from the list of led triggers */
+        write_lock(&triggers_list_lock);
+        list_del(&trigger->next_trig);
+        write_unlock(&triggers_list_lock);
+
+        /* Remove anyone actively using this trigger */
+        read_lock(&leds_list_lock);
+        list_for_each_entry(led_cdev, &leds_list, node) {
+                write_lock(&led_cdev->trigger_lock);
+                if (led_cdev->trigger == trigger)
+                        led_trigger_set(led_cdev, NULL);
+                write_unlock(&led_cdev->trigger_lock);
+        }
+        read_unlock(&leds_list_lock);
+}
+
+void led_trigger_unregister_simple(struct led_trigger *trigger)
+{
+        led_trigger_unregister(trigger);
+        kfree(trigger);
+}
+
+/* Used by LED Class */
+EXPORT_SYMBOL_GPL(led_trigger_set);
+EXPORT_SYMBOL_GPL(led_trigger_set_default);
+EXPORT_SYMBOL_GPL(led_trigger_show);
+EXPORT_SYMBOL_GPL(led_trigger_store);
+
+/* LED Trigger Interface */
+EXPORT_SYMBOL_GPL(led_trigger_register);
+EXPORT_SYMBOL_GPL(led_trigger_unregister);
+
+/* Simple LED Tigger Interface */
+EXPORT_SYMBOL_GPL(led_trigger_register_simple);
+EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
+EXPORT_SYMBOL_GPL(led_trigger_event);
+
+MODULE_AUTHOR("Richard Purdie");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LED Triggers Core");