1 files changed, 552 insertions, 0 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
new file mode 100644
index 000000000..aa39b2a48
--- /dev/null
+++ b/drivers/leds/led-class.c
@@ -0,0 +1,552 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * LED Class Core
+ *
+ * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
+ * Copyright (C) 2005-2007 Richard Purdie <rpurdie@openedhand.com>
+ */
+
+#include <linux/ctype.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <uapi/linux/uleds.h>
+#include <linux/of.h>
+#include "leds.h"
+
+static struct class *leds_class;
+
+static ssize_t brightness_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	/* no lock needed for this */
+	led_update_brightness(led_cdev);
+
+	return sprintf(buf, "%u\n", led_cdev->brightness);
+}
+
+static ssize_t brightness_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t size)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned long state;
+	ssize_t ret;
+
+	mutex_lock(&led_cdev->led_access);
+
+	if (led_sysfs_is_disabled(led_cdev)) {
+		ret = -EBUSY;
+		goto unlock;
+	}
+
+	ret = kstrtoul(buf, 10, &state);
+	if (ret)
+		goto unlock;
+
+	if (state == LED_OFF)
+		led_trigger_remove(led_cdev);
+	led_set_brightness(led_cdev, state);
+	flush_work(&led_cdev->set_brightness_work);
+
+	ret = size;
+unlock:
+	mutex_unlock(&led_cdev->led_access);
+	return ret;
+}
+static DEVICE_ATTR_RW(brightness);
+
+static ssize_t max_brightness_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", led_cdev->max_brightness);
+}
+static DEVICE_ATTR_RO(max_brightness);
+
+#ifdef CONFIG_LEDS_TRIGGERS
+static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
+static struct bin_attribute *led_trigger_bin_attrs[] = {
+	&bin_attr_trigger,
+	NULL,
+};
+static const struct attribute_group led_trigger_group = {
+	.bin_attrs = led_trigger_bin_attrs,
+};
+#endif
+
+static struct attribute *led_class_attrs[] = {
+	&dev_attr_brightness.attr,
+	&dev_attr_max_brightness.attr,
+	NULL,
+};
+
+static const struct attribute_group led_group = {
+	.attrs = led_class_attrs,
+};
+
+static const struct attribute_group *led_groups[] = {
+	&led_group,
+#ifdef CONFIG_LEDS_TRIGGERS
+	&led_trigger_group,
+#endif
+	NULL,
+};
+
+#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
+static ssize_t brightness_hw_changed_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	if (led_cdev->brightness_hw_changed == -1)
+		return -ENODATA;
+
+	return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
+}
+
+static DEVICE_ATTR_RO(brightness_hw_changed);
+
+static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
+{
+	struct device *dev = led_cdev->dev;
+	int ret;
+
+	ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
+	if (ret) {
+		dev_err(dev, "Error creating brightness_hw_changed\n");
+		return ret;
+	}
+
+	led_cdev->brightness_hw_changed_kn =
+		sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
+	if (!led_cdev->brightness_hw_changed_kn) {
+		dev_err(dev, "Error getting brightness_hw_changed kn\n");
+		device_remove_file(dev, &dev_attr_brightness_hw_changed);
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
+{
+	sysfs_put(led_cdev->brightness_hw_changed_kn);
+	device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
+}
+
+void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
+{
+	if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
+		return;
+
+	led_cdev->brightness_hw_changed = brightness;
+	sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
+}
+EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
+#else
+static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
+{
+	return 0;
+}
+static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
+{
+}
+#endif
+
+/**
+ * led_classdev_suspend - suspend an led_classdev.
+ * @led_cdev: the led_classdev to suspend.
+ */
+void led_classdev_suspend(struct led_classdev *led_cdev)
+{
+	led_cdev->flags |= LED_SUSPENDED;
+	led_set_brightness_nopm(led_cdev, 0);
+	flush_work(&led_cdev->set_brightness_work);
+}
+EXPORT_SYMBOL_GPL(led_classdev_suspend);
+
+/**
+ * led_classdev_resume - resume an led_classdev.
+ * @led_cdev: the led_classdev to resume.
+ */
+void led_classdev_resume(struct led_classdev *led_cdev)
+{
+	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
+
+	if (led_cdev->flash_resume)
+		led_cdev->flash_resume(led_cdev);
+
+	led_cdev->flags &= ~LED_SUSPENDED;
+}
+EXPORT_SYMBOL_GPL(led_classdev_resume);
+
+#ifdef CONFIG_PM_SLEEP
+static int led_suspend(struct device *dev)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
+		led_classdev_suspend(led_cdev);
+
+	return 0;
+}
+
+static int led_resume(struct device *dev)
+{
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+	if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
+		led_classdev_resume(led_cdev);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
+
+/**
+ * of_led_get() - request a LED device via the LED framework
+ * @np: device node to get the LED device from
+ * @index: the index of the LED
+ *
+ * Returns the LED device parsed from the phandle specified in the "leds"
+ * property of a device tree node or a negative error-code on failure.
+ */
+struct led_classdev *of_led_get(struct device_node *np, int index)
+{
+	struct device *led_dev;
+	struct led_classdev *led_cdev;
+	struct device_node *led_node;
+
+	led_node = of_parse_phandle(np, "leds", index);
+	if (!led_node)
+		return ERR_PTR(-ENOENT);
+
+	led_dev = class_find_device_by_of_node(leds_class, led_node);
+	of_node_put(led_node);
+	put_device(led_dev);
+
+	if (!led_dev)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	led_cdev = dev_get_drvdata(led_dev);
+
+	if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
+		put_device(led_cdev->dev);
+		return ERR_PTR(-ENODEV);
+	}
+
+	return led_cdev;
+}
+EXPORT_SYMBOL_GPL(of_led_get);
+
+/**
+ * led_put() - release a LED device
+ * @led_cdev: LED device
+ */
+void led_put(struct led_classdev *led_cdev)
+{
+	module_put(led_cdev->dev->parent->driver->owner);
+	put_device(led_cdev->dev);
+}
+EXPORT_SYMBOL_GPL(led_put);
+
+static void devm_led_release(struct device *dev, void *res)
+{
+	struct led_classdev **p = res;
+
+	led_put(*p);
+}
+
+/**
+ * devm_of_led_get - Resource-managed request of a LED device
+ * @dev:	LED consumer
+ * @index:	index of the LED to obtain in the consumer
+ *
+ * The device node of the device is parse to find the request LED device.
+ * The LED device returned from this function is automatically released
+ * on driver detach.
+ *
+ * @return a pointer to a LED device or ERR_PTR(errno) on failure.
+ */
+struct led_classdev *__must_check devm_of_led_get(struct device *dev,
+						  int index)
+{
+	struct led_classdev *led;
+	struct led_classdev **dr;
+
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
+	led = of_led_get(dev->of_node, index);
+	if (IS_ERR(led))
+		return led;
+
+	dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),
+			  GFP_KERNEL);
+	if (!dr) {
+		led_put(led);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	*dr = led;
+	devres_add(dev, dr);
+
+	return led;
+}
+EXPORT_SYMBOL_GPL(devm_of_led_get);
+
+static int led_classdev_next_name(const char *init_name, char *name,
+				  size_t len)
+{
+	unsigned int i = 0;
+	int ret = 0;
+	struct device *dev;
+
+	strlcpy(name, init_name, len);
+
+	while ((ret < len) &&
+	       (dev = class_find_device_by_name(leds_class, name))) {
+		put_device(dev);
+		ret = snprintf(name, len, "%s_%u", init_name, ++i);
+	}
+
+	if (ret >= len)
+		return -ENOMEM;
+
+	return i;
+}
+
+/**
+ * led_classdev_register_ext - register a new object of led_classdev class
+ *			       with init data.
+ *
+ * @parent: parent of LED device
+ * @led_cdev: the led_classdev structure for this device.
+ * @init_data: LED class device initialization data
+ */
+int led_classdev_register_ext(struct device *parent,
+			      struct led_classdev *led_cdev,
+			      struct led_init_data *init_data)
+{
+	char composed_name[LED_MAX_NAME_SIZE];
+	char final_name[LED_MAX_NAME_SIZE];
+	const char *proposed_name = composed_name;
+	int ret;
+
+	if (init_data) {
+		if (init_data->devname_mandatory && !init_data->devicename) {
+			dev_err(parent, "Mandatory device name is missing");
+			return -EINVAL;
+		}
+		ret = led_compose_name(parent, init_data, composed_name);
+		if (ret < 0)
+			return ret;
+
+		if (init_data->fwnode) {
+			fwnode_property_read_string(init_data->fwnode,
+				"linux,default-trigger",
+				&led_cdev->default_trigger);
+
+			if (fwnode_property_present(init_data->fwnode,
+						    "retain-state-shutdown"))
+				led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
+		}
+	} else {
+		proposed_name = led_cdev->name;
+	}
+
+	ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&led_cdev->led_access);
+	mutex_lock(&led_cdev->led_access);
+	led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
+				led_cdev, led_cdev->groups, "%s", final_name);
+	if (IS_ERR(led_cdev->dev)) {
+		mutex_unlock(&led_cdev->led_access);
+		return PTR_ERR(led_cdev->dev);
+	}
+	if (init_data && init_data->fwnode)
+		device_set_node(led_cdev->dev, init_data->fwnode);
+
+	if (ret)
+		dev_warn(parent, "Led %s renamed to %s due to name collision",
+				proposed_name, dev_name(led_cdev->dev));
+
+	if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
+		ret = led_add_brightness_hw_changed(led_cdev);
+		if (ret) {
+			device_unregister(led_cdev->dev);
+			led_cdev->dev = NULL;
+			mutex_unlock(&led_cdev->led_access);
+			return ret;
+		}
+	}
+
+	led_cdev->work_flags = 0;
+#ifdef CONFIG_LEDS_TRIGGERS
+	init_rwsem(&led_cdev->trigger_lock);
+#endif
+#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
+	led_cdev->brightness_hw_changed = -1;
+#endif
+	/* add to the list of leds */
+	down_write(&leds_list_lock);
+	list_add_tail(&led_cdev->node, &leds_list);
+	up_write(&leds_list_lock);
+
+	if (!led_cdev->max_brightness)
+		led_cdev->max_brightness = LED_FULL;
+
+	led_update_brightness(led_cdev);
+
+	led_init_core(led_cdev);
+
+#ifdef CONFIG_LEDS_TRIGGERS
+	led_trigger_set_default(led_cdev);
+#endif
+
+	mutex_unlock(&led_cdev->led_access);
+
+	dev_dbg(parent, "Registered led device: %s\n",
+			led_cdev->name);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(led_classdev_register_ext);
+
+/**
+ * led_classdev_unregister - unregisters a object of led_properties class.
+ * @led_cdev: the led device to unregister
+ *
+ * Unregisters a previously registered via led_classdev_register object.
+ */
+void led_classdev_unregister(struct led_classdev *led_cdev)
+{
+	if (IS_ERR_OR_NULL(led_cdev->dev))
+		return;
+
+#ifdef CONFIG_LEDS_TRIGGERS
+	down_write(&led_cdev->trigger_lock);
+	if (led_cdev->trigger)
+		led_trigger_set(led_cdev, NULL);
+	up_write(&led_cdev->trigger_lock);
+#endif
+
+	led_cdev->flags |= LED_UNREGISTERING;
+
+	/* Stop blinking */
+	led_stop_software_blink(led_cdev);
+
+	if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
+		led_set_brightness(led_cdev, LED_OFF);
+
+	flush_work(&led_cdev->set_brightness_work);
+
+	if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
+		led_remove_brightness_hw_changed(led_cdev);
+
+	device_unregister(led_cdev->dev);
+
+	down_write(&leds_list_lock);
+	list_del(&led_cdev->node);
+	up_write(&leds_list_lock);
+
+	mutex_destroy(&led_cdev->led_access);
+}
+EXPORT_SYMBOL_GPL(led_classdev_unregister);
+
+static void devm_led_classdev_release(struct device *dev, void *res)
+{
+	led_classdev_unregister(*(struct led_classdev **)res);
+}
+
+/**
+ * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
+ *
+ * @parent: parent of LED device
+ * @led_cdev: the led_classdev structure for this device.
+ * @init_data: LED class device initialization data
+ */
+int devm_led_classdev_register_ext(struct device *parent,
+				   struct led_classdev *led_cdev,
+				   struct led_init_data *init_data)
+{
+	struct led_classdev **dr;
+	int rc;
+
+	dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	rc = led_classdev_register_ext(parent, led_cdev, init_data);
+	if (rc) {
+		devres_free(dr);
+		return rc;
+	}
+
+	*dr = led_cdev;
+	devres_add(parent, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
+
+static int devm_led_classdev_match(struct device *dev, void *res, void *data)
+{
+	struct led_classdev **p = res;
+
+	if (WARN_ON(!p || !*p))
+		return 0;
+
+	return *p == data;
+}
+
+/**
+ * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
+ * @dev: The device to unregister.
+ * @led_cdev: the led_classdev structure for this device.
+ */
+void devm_led_classdev_unregister(struct device *dev,
+				  struct led_classdev *led_cdev)
+{
+	WARN_ON(devres_release(dev,
+			       devm_led_classdev_release,
+			       devm_led_classdev_match, led_cdev));
+}
+EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
+
+static int __init leds_init(void)
+{
+	leds_class = class_create(THIS_MODULE, "leds");
+	if (IS_ERR(leds_class))
+		return PTR_ERR(leds_class);
+	leds_class->pm = &leds_class_dev_pm_ops;
+	leds_class->dev_groups = led_groups;
+	return 0;
+}
+
+static void __exit leds_exit(void)
+{
+	class_destroy(leds_class);
+}
+
+subsys_initcall(leds_init);
+module_exit(leds_exit);
+
+MODULE_AUTHOR("John Lenz, Richard Purdie");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LED Class Interface");