v4.19.13 snapshot.
diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
new file mode 100644
index 0000000..17d73db
--- /dev/null
+++ b/drivers/leds/led-triggers.c
@@ -0,0 +1,399 @@
+/*
+ * 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/export.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);
+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);
+ struct led_trigger *trig;
+ int ret = count;
+
+ mutex_lock(&led_cdev->led_access);
+
+ if (led_sysfs_is_disabled(led_cdev)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ if (sysfs_streq(buf, "none")) {
+ led_trigger_remove(led_cdev);
+ goto unlock;
+ }
+
+ down_read(&triggers_list_lock);
+ list_for_each_entry(trig, &trigger_list, next_trig) {
+ if (sysfs_streq(buf, 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;
+ }
+ }
+ /* we come here only if buf matches no trigger */
+ ret = -EINVAL;
+ 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 += scnprintf(buf+len, PAGE_SIZE - len, "[none] ");
+ else
+ len += scnprintf(buf+len, PAGE_SIZE - len, "none ");
+
+ list_for_each_entry(trig, &trigger_list, next_trig) {
+ if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
+ trig->name))
+ len += scnprintf(buf+len, PAGE_SIZE - len, "[%s] ",
+ trig->name);
+ else
+ len += scnprintf(buf+len, PAGE_SIZE - len, "%s ",
+ trig->name);
+ }
+ up_read(&led_cdev->trigger_lock);
+ up_read(&triggers_list_lock);
+
+ len += scnprintf(len+buf, PAGE_SIZE - len, "\n");
+ return len;
+}
+EXPORT_SYMBOL_GPL(led_trigger_show);
+
+/* Caller must ensure led_cdev->trigger_lock held */
+int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
+{
+ unsigned long flags;
+ char *event = NULL;
+ char *envp[2];
+ const char *name;
+ int ret;
+
+ if (!led_cdev->trigger && !trig)
+ return 0;
+
+ 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);
+ device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
+ led_cdev->trigger = NULL;
+ led_cdev->trigger_data = NULL;
+ led_cdev->activated = false;
+ 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)
+ ret = trig->activate(led_cdev);
+ else
+ ret = 0;
+
+ if (ret)
+ goto err_activate;
+
+ ret = device_add_groups(led_cdev->dev, trig->groups);
+ if (ret) {
+ dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
+ goto err_add_groups;
+ }
+ }
+
+ if (event) {
+ envp[0] = event;
+ envp[1] = NULL;
+ if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
+ dev_err(led_cdev->dev,
+ "%s: Error sending uevent\n", __func__);
+ kfree(event);
+ }
+
+ return 0;
+
+err_add_groups:
+
+ if (trig->deactivate)
+ trig->deactivate(led_cdev);
+err_activate:
+
+ led_cdev->trigger = NULL;
+ led_cdev->trigger_data = NULL;
+ 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);
+ led_set_brightness(led_cdev, LED_OFF);
+
+ return ret;
+}
+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);
+
+static void devm_led_trigger_release(struct device *dev, void *res)
+{
+ led_trigger_unregister(*(struct led_trigger **)res);
+}
+
+int devm_led_trigger_register(struct device *dev,
+ struct led_trigger *trig)
+{
+ struct led_trigger **dr;
+ int rc;
+
+ dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
+ GFP_KERNEL);
+ if (!dr)
+ return -ENOMEM;
+
+ *dr = trig;
+
+ rc = led_trigger_register(trig);
+ if (rc)
+ devres_free(dr);
+ else
+ devres_add(dev, dr);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(devm_led_trigger_register);
+
+/* 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);