[linux.git] / drivers / leds / led-class.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * LED Class Core
 *
 * Copyright (C) 2005 John Lenz <[email protected]>
 * Copyright (C) 2005-2007 Richard Purdie <[email protected]>
 */

#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 DEFINE_MUTEX(leds_lookup_lock);
static LIST_HEAD(leds_lookup_list);

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);

static struct led_classdev *led_module_get(struct device *led_dev)
{
	struct led_classdev *led_cdev;

	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;
}

static const struct class leds_class = {
	.name = "leds",
	.dev_groups = led_groups,
	.pm = &leds_class_dev_pm_ops,
};

/**
 * 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 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);

	return led_module_get(led_dev);
}
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);
}

static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led)
{
	struct led_classdev **dr;

	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;
}

/**
 * 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;

	if (!dev)
		return ERR_PTR(-EINVAL);

	led = of_led_get(dev->of_node, index);
	if (IS_ERR(led))
		return led;

	return __devm_led_get(dev, led);
}
EXPORT_SYMBOL_GPL(devm_of_led_get);

/**
 * led_get() - request a LED device via the LED framework
 * @dev: device for which to get the LED device
 * @con_id: name of the LED from the device's point of view
 *
 * @return a pointer to a LED device or ERR_PTR(errno) on failure.
 */
struct led_classdev *led_get(struct device *dev, char *con_id)
{
	struct led_lookup_data *lookup;
	const char *provider = NULL;
	struct device *led_dev;

	mutex_lock(&leds_lookup_lock);
	list_for_each_entry(lookup, &leds_lookup_list, list) {
		if (!strcmp(lookup->dev_id, dev_name(dev)) &&
		    !strcmp(lookup->con_id, con_id)) {
			provider = kstrdup_const(lookup->provider, GFP_KERNEL);
			break;
		}
	}
	mutex_unlock(&leds_lookup_lock);

	if (!provider)
		return ERR_PTR(-ENOENT);

	led_dev = class_find_device_by_name(&leds_class, provider);
	kfree_const(provider);

	return led_module_get(led_dev);
}
EXPORT_SYMBOL_GPL(led_get);

/**
 * devm_led_get() - request a LED device via the LED framework
 * @dev: device for which to get the LED device
 * @con_id: name of the LED from the device's point of view
 *
 * 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 *devm_led_get(struct device *dev, char *con_id)
{
	struct led_classdev *led;

	led = led_get(dev, con_id);
	if (IS_ERR(led))
		return led;

	return __devm_led_get(dev, led);
}
EXPORT_SYMBOL_GPL(devm_led_get);

/**
 * led_add_lookup() - Add a LED lookup table entry
 * @led_lookup: the lookup table entry to add
 *
 * Add a LED lookup table entry. On systems without devicetree the lookup table
 * is used by led_get() to find LEDs.
 */
void led_add_lookup(struct led_lookup_data *led_lookup)
{
	mutex_lock(&leds_lookup_lock);
	list_add_tail(&led_lookup->list, &leds_lookup_list);
	mutex_unlock(&leds_lookup_lock);
}
EXPORT_SYMBOL_GPL(led_add_lookup);

/**
 * led_remove_lookup() - Remove a LED lookup table entry
 * @led_lookup: the lookup table entry to remove
 */
void led_remove_lookup(struct led_lookup_data *led_lookup)
{
	mutex_lock(&leds_lookup_lock);
	list_del(&led_lookup->list);
	mutex_unlock(&leds_lookup_lock);
}
EXPORT_SYMBOL_GPL(led_remove_lookup);

/**
 * devm_of_led_get_optional - Resource-managed request of an optional LED device
 * @dev:	LED consumer
 * @index:	index of the LED to obtain in the consumer
 *
 * The device node of the device is parsed to find the requested LED device.
 * The LED device returned from this function is automatically released
 * on driver detach.
 *
 * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
 * led was not found.
 */
struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
							int index)
{
	struct led_classdev *led;

	led = devm_of_led_get(dev, index);
	if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
		return NULL;

	return led;
}
EXPORT_SYMBOL_GPL(devm_of_led_get_optional);

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;

	strscpy(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;

			fwnode_property_read_u32(init_data->fwnode,
				"max-brightness",
				&led_cdev->max_brightness);

			if (fwnode_property_present(init_data->fwnode, "color"))
				fwnode_property_read_u32(init_data->fwnode, "color",
							 &led_cdev->color);
		}
	} else {
		proposed_name = led_cdev->name;
	}

	ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
	if (ret < 0)
		return ret;
	else if (ret && led_cdev->flags & LED_REJECT_NAME_CONFLICT)
		return -EEXIST;
	else if (ret)
		dev_warn(parent, "Led %s renamed to %s due to name collision\n",
			 proposed_name, final_name);

	if (led_cdev->color >= LED_COLOR_ID_MAX)
		dev_warn(parent, "LED %s color identifier out of range\n", final_name);

	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 (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)
{
	return class_register(&leds_class);
}

static void __exit leds_exit(void)
{
	class_unregister(&leds_class);
}

subsys_initcall(leds_init);
module_exit(leds_exit);

MODULE_AUTHOR("John Lenz, Richard Purdie");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LED Class Interface");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
c72a1d60 RP	2	/*
	3	* LED Class Core
	4	*
	5	* Copyright (C) 2005 John Lenz <[email protected]>
f8a7c6fe	6	* Copyright (C) 2005-2007 Richard Purdie <[email protected]>
c72a1d60 RP	7	*/
c72a1d60 RP	8
04713306 JA	9	#include <linux/ctype.h>
	10	#include <linux/device.h>
	11	#include <linux/err.h>
c72a1d60	12	#include <linux/init.h>
04713306 JA	13	#include <linux/kernel.h>
04713306 JA	14	#include <linux/leds.h>
c72a1d60	15	#include <linux/list.h>
04713306	16	#include <linux/module.h>
fd81d7e9	17	#include <linux/property.h>
04713306	18	#include <linux/slab.h>
c72a1d60	19	#include <linux/spinlock.h>
9067359f	20	#include <linux/timer.h>
eb1ce746	21	#include <uapi/linux/uleds.h>
699a8c7c	22	#include <linux/of.h>
c72a1d60 RP	23	#include "leds.h"
c72a1d60 RP	24
abc3100f HG	25	static DEFINE_MUTEX(leds_lookup_lock);
abc3100f HG	26	static LIST_HEAD(leds_lookup_list);
c72a1d60	27
5baa7503	28	static ssize_t brightness_show(struct device *dev,
f8a7c6fe	29	struct device_attribute attr, char buf)
c72a1d60	30	{
f8a7c6fe	31	struct led_classdev *led_cdev = dev_get_drvdata(dev);
c72a1d60 RP	32
c72a1d60 RP	33	/* no lock needed for this */
29d76dfa	34	led_update_brightness(led_cdev);
c72a1d60	35
dd8e5a20	36	return sprintf(buf, "%u\n", led_cdev->brightness);
c72a1d60 RP	37	}
c72a1d60 RP	38
5baa7503	39	static ssize_t brightness_store(struct device *dev,
f8a7c6fe	40	struct device_attribute attr, const char buf, size_t size)
c72a1d60	41	{
f8a7c6fe	42	struct led_classdev *led_cdev = dev_get_drvdata(dev);
872b86be	43	unsigned long state;
acd899e4 JA	44	ssize_t ret;
	45
	46	mutex_lock(&led_cdev->led_access);
	47
	48	if (led_sysfs_is_disabled(led_cdev)) {
	49	ret = -EBUSY;
	50	goto unlock;
	51	}
c72a1d60	52
872b86be SK	53	ret = kstrtoul(buf, 10, &state);
872b86be SK	54	if (ret)
acd899e4	55	goto unlock;
3dc7b82e	56
872b86be SK	57	if (state == LED_OFF)
872b86be SK	58	led_trigger_remove(led_cdev);
4d71a4a1	59	led_set_brightness(led_cdev, state);
0db37915	60	flush_work(&led_cdev->set_brightness_work);
0013b23d	61
acd899e4 JA	62	ret = size;
	63	unlock:
	64	mutex_unlock(&led_cdev->led_access);
	65	return ret;
c72a1d60	66	}
5baa7503	67	static DEVICE_ATTR_RW(brightness);
c72a1d60	68
38419612	69	static ssize_t max_brightness_show(struct device *dev,
1bd465e6 GL	70	struct device_attribute attr, char buf)
	71	{
	72	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	73
	74	return sprintf(buf, "%u\n", led_cdev->max_brightness);
	75	}
38419612	76	static DEVICE_ATTR_RO(max_brightness);
1bd465e6	77
c3bc9956	78	#ifdef CONFIG_LEDS_TRIGGERS
11f70002 AM	79	static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
	80	static struct bin_attribute *led_trigger_bin_attrs[] = {
	81	&bin_attr_trigger,
5baa7503 GKH	82	NULL,
	83	};
	84	static const struct attribute_group led_trigger_group = {
11f70002	85	.bin_attrs = led_trigger_bin_attrs,
5baa7503 GKH	86	};
	87	#endif
	88
	89	static struct attribute *led_class_attrs[] = {
	90	&dev_attr_brightness.attr,
	91	&dev_attr_max_brightness.attr,
	92	NULL,
	93	};
	94
	95	static const struct attribute_group led_group = {
	96	.attrs = led_class_attrs,
	97	};
	98
	99	static const struct attribute_group *led_groups[] = {
	100	&led_group,
	101	#ifdef CONFIG_LEDS_TRIGGERS
	102	&led_trigger_group,
c3bc9956	103	#endif
5baa7503	104	NULL,
14b5d6dd	105	};
c72a1d60	106
0cb8eb30 HG	107	#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
	108	static ssize_t brightness_hw_changed_show(struct device *dev,
	109	struct device_attribute attr, char buf)
	110	{
	111	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	112
	113	if (led_cdev->brightness_hw_changed == -1)
	114	return -ENODATA;
	115
	116	return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
	117	}
	118
	119	static DEVICE_ATTR_RO(brightness_hw_changed);
	120
	121	static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
	122	{
	123	struct device *dev = led_cdev->dev;
	124	int ret;
	125
	126	ret = device_create_file(dev, &dev_attr_brightness_hw_changed);
	127	if (ret) {
	128	dev_err(dev, "Error creating brightness_hw_changed\n");
	129	return ret;
	130	}
	131
	132	led_cdev->brightness_hw_changed_kn =
	133	sysfs_get_dirent(dev->kobj.sd, "brightness_hw_changed");
	134	if (!led_cdev->brightness_hw_changed_kn) {
	135	dev_err(dev, "Error getting brightness_hw_changed kn\n");
	136	device_remove_file(dev, &dev_attr_brightness_hw_changed);
	137	return -ENXIO;
	138	}
	139
	140	return 0;
	141	}
	142
	143	static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
	144	{
	145	sysfs_put(led_cdev->brightness_hw_changed_kn);
	146	device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
	147	}
	148
af0bfab9	149	void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
0cb8eb30 HG	150	{
	151	if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
	152	return;
	153
	154	led_cdev->brightness_hw_changed = brightness;
	155	sysfs_notify_dirent(led_cdev->brightness_hw_changed_kn);
	156	}
	157	EXPORT_SYMBOL_GPL(led_classdev_notify_brightness_hw_changed);
	158	#else
	159	static int led_add_brightness_hw_changed(struct led_classdev *led_cdev)
	160	{
	161	return 0;
	162	}
	163	static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
	164	{
	165	}
	166	#endif
	167
c72a1d60 RP	168	/**
	169	* led_classdev_suspend - suspend an led_classdev.
	170	* @led_cdev: the led_classdev to suspend.
	171	*/
	172	void led_classdev_suspend(struct led_classdev *led_cdev)
	173	{
	174	led_cdev->flags \|= LED_SUSPENDED;
81fe8e5b	175	led_set_brightness_nopm(led_cdev, 0);
302a085c	176	flush_work(&led_cdev->set_brightness_work);
c72a1d60 RP	177	}
	178	EXPORT_SYMBOL_GPL(led_classdev_suspend);
	179
	180	/**
	181	* led_classdev_resume - resume an led_classdev.
	182	* @led_cdev: the led_classdev to resume.
	183	*/
	184	void led_classdev_resume(struct led_classdev *led_cdev)
	185	{
81fe8e5b	186	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
7aea8389 JA	187
	188	if (led_cdev->flash_resume)
	189	led_cdev->flash_resume(led_cdev);
	190
c72a1d60 RP	191	led_cdev->flags &= ~LED_SUSPENDED;
	192	}
	193	EXPORT_SYMBOL_GPL(led_classdev_resume);
	194
084609bf	195	#ifdef CONFIG_PM_SLEEP
73e1ab41	196	static int led_suspend(struct device *dev)
859cb7f2 RP	197	{
	198	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	199
	200	if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
	201	led_classdev_suspend(led_cdev);
	202
	203	return 0;
	204	}
	205
	206	static int led_resume(struct device *dev)
	207	{
	208	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	209
	210	if (led_cdev->flags & LED_CORE_SUSPENDRESUME)
	211	led_classdev_resume(led_cdev);
	212
	213	return 0;
	214	}
084609bf	215	#endif
859cb7f2	216
084609bf	217	static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
73e1ab41	218
fafef58e HG	219	static struct led_classdev led_module_get(struct device led_dev)
	220	{
	221	struct led_classdev *led_cdev;
	222
	223	if (!led_dev)
	224	return ERR_PTR(-EPROBE_DEFER);
	225
	226	led_cdev = dev_get_drvdata(led_dev);
	227
	228	if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
	229	put_device(led_cdev->dev);
	230	return ERR_PTR(-ENODEV);
	231	}
	232
	233	return led_cdev;
	234	}
	235
43a707ae IO	236	static const struct class leds_class = {
	237	.name = "leds",
	238	.dev_groups = led_groups,
	239	.pm = &leds_class_dev_pm_ops,
	240	};
	241
699a8c7c TV	242	/**
	243	* of_led_get() - request a LED device via the LED framework
	244	* @np: device node to get the LED device from
	245	* @index: the index of the LED
	246	*
	247	* Returns the LED device parsed from the phandle specified in the "leds"
	248	* property of a device tree node or a negative error-code on failure.
	249	*/
	250	struct led_classdev of_led_get(struct device_node np, int index)
	251	{
	252	struct device *led_dev;
699a8c7c TV	253	struct device_node *led_node;
	254
	255	led_node = of_parse_phandle(np, "leds", index);
	256	if (!led_node)
	257	return ERR_PTR(-ENOENT);
	258
43a707ae	259	led_dev = class_find_device_by_of_node(&leds_class, led_node);
699a8c7c TV	260	of_node_put(led_node);
699a8c7c TV	261
fafef58e	262	return led_module_get(led_dev);
699a8c7c TV	263	}
	264	EXPORT_SYMBOL_GPL(of_led_get);
	265
	266	/**
	267	* led_put() - release a LED device
	268	* @led_cdev: LED device
	269	*/
	270	void led_put(struct led_classdev *led_cdev)
	271	{
	272	module_put(led_cdev->dev->parent->driver->owner);
44511094	273	put_device(led_cdev->dev);
699a8c7c TV	274	}
	275	EXPORT_SYMBOL_GPL(led_put);
	276
e389240a JJH	277	static void devm_led_release(struct device dev, void res)
	278	{
	279	struct led_classdev **p = res;
	280
	281	led_put(*p);
	282	}
	283
537bdca2 HG	284	static struct led_classdev __devm_led_get(struct device dev, struct led_classdev *led)
	285	{
	286	struct led_classdev **dr;
	287
	288	dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), GFP_KERNEL);
	289	if (!dr) {
	290	led_put(led);
	291	return ERR_PTR(-ENOMEM);
	292	}
	293
	294	*dr = led;
	295	devres_add(dev, dr);
	296
	297	return led;
	298	}
	299
e389240a JJH	300	/**
	301	* devm_of_led_get - Resource-managed request of a LED device
	302	* @dev: LED consumer
	303	* @index: index of the LED to obtain in the consumer
	304	*
	305	* The device node of the device is parse to find the request LED device.
	306	* The LED device returned from this function is automatically released
	307	* on driver detach.
	308	*
	309	* @return a pointer to a LED device or ERR_PTR(errno) on failure.
	310	*/
	311	struct led_classdev __must_check devm_of_led_get(struct device dev,
	312	int index)
	313	{
	314	struct led_classdev *led;
e389240a JJH	315
	316	if (!dev)
	317	return ERR_PTR(-EINVAL);
	318
e389240a JJH	319	led = of_led_get(dev->of_node, index);
	320	if (IS_ERR(led))
	321	return led;
	322
537bdca2	323	return __devm_led_get(dev, led);
e389240a JJH	324	}
	325	EXPORT_SYMBOL_GPL(devm_of_led_get);
	326
abc3100f HG	327	/**
	328	* led_get() - request a LED device via the LED framework
	329	* @dev: device for which to get the LED device
	330	* @con_id: name of the LED from the device's point of view
	331	*
	332	* @return a pointer to a LED device or ERR_PTR(errno) on failure.
	333	*/
	334	struct led_classdev led_get(struct device dev, char *con_id)
	335	{
	336	struct led_lookup_data *lookup;
	337	const char *provider = NULL;
	338	struct device *led_dev;
	339
	340	mutex_lock(&leds_lookup_lock);
	341	list_for_each_entry(lookup, &leds_lookup_list, list) {
	342	if (!strcmp(lookup->dev_id, dev_name(dev)) &&
	343	!strcmp(lookup->con_id, con_id)) {
	344	provider = kstrdup_const(lookup->provider, GFP_KERNEL);
	345	break;
	346	}
	347	}
	348	mutex_unlock(&leds_lookup_lock);
	349
	350	if (!provider)
	351	return ERR_PTR(-ENOENT);
	352
43a707ae	353	led_dev = class_find_device_by_name(&leds_class, provider);
abc3100f HG	354	kfree_const(provider);
	355
	356	return led_module_get(led_dev);
	357	}
	358	EXPORT_SYMBOL_GPL(led_get);
	359
	360	/**
	361	* devm_led_get() - request a LED device via the LED framework
	362	* @dev: device for which to get the LED device
	363	* @con_id: name of the LED from the device's point of view
	364	*
	365	* The LED device returned from this function is automatically released
	366	* on driver detach.
	367	*
	368	* @return a pointer to a LED device or ERR_PTR(errno) on failure.
	369	*/
	370	struct led_classdev devm_led_get(struct device dev, char *con_id)
	371	{
	372	struct led_classdev *led;
	373
	374	led = led_get(dev, con_id);
	375	if (IS_ERR(led))
	376	return led;
	377
	378	return __devm_led_get(dev, led);
	379	}
	380	EXPORT_SYMBOL_GPL(devm_led_get);
	381
	382	/**
	383	* led_add_lookup() - Add a LED lookup table entry
	384	* @led_lookup: the lookup table entry to add
	385	*
	386	* Add a LED lookup table entry. On systems without devicetree the lookup table
	387	* is used by led_get() to find LEDs.
	388	*/
	389	void led_add_lookup(struct led_lookup_data *led_lookup)
	390	{
	391	mutex_lock(&leds_lookup_lock);
	392	list_add_tail(&led_lookup->list, &leds_lookup_list);
	393	mutex_unlock(&leds_lookup_lock);
	394	}
	395	EXPORT_SYMBOL_GPL(led_add_lookup);
	396
	397	/**
	398	* led_remove_lookup() - Remove a LED lookup table entry
	399	* @led_lookup: the lookup table entry to remove
	400	*/
	401	void led_remove_lookup(struct led_lookup_data *led_lookup)
	402	{
	403	mutex_lock(&leds_lookup_lock);
	404	list_del(&led_lookup->list);
	405	mutex_unlock(&leds_lookup_lock);
	406	}
	407	EXPORT_SYMBOL_GPL(led_remove_lookup);
	408
afb48153 JJH	409	/**
	410	* devm_of_led_get_optional - Resource-managed request of an optional LED device
	411	* @dev: LED consumer
	412	* @index: index of the LED to obtain in the consumer
	413	*
	414	* The device node of the device is parsed to find the requested LED device.
	415	* The LED device returned from this function is automatically released
	416	* on driver detach.
	417	*
	418	* @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
	419	* led was not found.
	420	*/
	421	struct led_classdev __must_check devm_of_led_get_optional(struct device dev,
	422	int index)
	423	{
	424	struct led_classdev *led;
	425
	426	led = devm_of_led_get(dev, index);
	427	if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
	428	return NULL;
	429
	430	return led;
	431	}
	432	EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
	433
a96aa64c RR	434	static int led_classdev_next_name(const char init_name, char name,
	435	size_t len)
	436	{
	437	unsigned int i = 0;
	438	int ret = 0;
e5b5a61f	439	struct device *dev;
a96aa64c	440
bf4a35e9	441	strscpy(name, init_name, len);
a96aa64c	442
e5b5a61f	443	while ((ret < len) &&
43a707ae	444	(dev = class_find_device_by_name(&leds_class, name))) {
e5b5a61f	445	put_device(dev);
a96aa64c	446	ret = snprintf(name, len, "%s_%u", init_name, ++i);
e5b5a61f	447	}
a96aa64c RR	448
	449	if (ret >= len)
	450	return -ENOMEM;
	451
	452	return i;
	453	}
	454
c72a1d60	455	/**
b2b998c0 JA	456	* led_classdev_register_ext - register a new object of led_classdev class
b2b998c0 JA	457	* with init data.
442c6098 RM	458	*
442c6098 RM	459	* @parent: parent of LED device
c72a1d60	460	* @led_cdev: the led_classdev structure for this device.
b2b998c0	461	* @init_data: LED class device initialization data
c72a1d60	462	*/
b2b998c0 JA	463	int led_classdev_register_ext(struct device *parent,
	464	struct led_classdev *led_cdev,
	465	struct led_init_data *init_data)
c72a1d60	466	{
bb4e9af0 JA	467	char composed_name[LED_MAX_NAME_SIZE];
	468	char final_name[LED_MAX_NAME_SIZE];
	469	const char *proposed_name = composed_name;
a96aa64c RR	470	int ret;
a96aa64c RR	471
bb4e9af0 JA	472	if (init_data) {
	473	if (init_data->devname_mandatory && !init_data->devicename) {
	474	dev_err(parent, "Mandatory device name is missing");
	475	return -EINVAL;
	476	}
	477	ret = led_compose_name(parent, init_data, composed_name);
	478	if (ret < 0)
	479	return ret;
c49d6cab	480
41906632	481	if (init_data->fwnode) {
c49d6cab MB	482	fwnode_property_read_string(init_data->fwnode,
	483	"linux,default-trigger",
	484	&led_cdev->default_trigger);
41906632 EJ	485
	486	if (fwnode_property_present(init_data->fwnode,
	487	"retain-state-shutdown"))
	488	led_cdev->flags \|= LED_RETAIN_AT_SHUTDOWN;
7cd7a299 AR	489
	490	fwnode_property_read_u32(init_data->fwnode,
	491	"max-brightness",
	492	&led_cdev->max_brightness);
c7d80059 JJH	493
	494	if (fwnode_property_present(init_data->fwnode, "color"))
	495	fwnode_property_read_u32(init_data->fwnode, "color",
	496	&led_cdev->color);
41906632	497	}
bb4e9af0 JA	498	} else {
	499	proposed_name = led_cdev->name;
	500	}
	501
	502	ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
a96aa64c RR	503	if (ret < 0)
a96aa64c RR	504	return ret;
6b0d3355 TW	505	else if (ret && led_cdev->flags & LED_REJECT_NAME_CONFLICT)
6b0d3355 TW	506	return -EEXIST;
bfefbecd TW	507	else if (ret)
	508	dev_warn(parent, "Led %s renamed to %s due to name collision\n",
	509	proposed_name, final_name);
a96aa64c	510
c7d80059 JJH	511	if (led_cdev->color >= LED_COLOR_ID_MAX)
	512	dev_warn(parent, "LED %s color identifier out of range\n", final_name);
	513
6d71021a LH	514	mutex_init(&led_cdev->led_access);
6d71021a LH	515	mutex_lock(&led_cdev->led_access);
43a707ae IO	516	led_cdev->dev = device_create_with_groups(&leds_class, parent, 0,
43a707ae IO	517	led_cdev, led_cdev->groups, "%s", final_name);
6d71021a LH	518	if (IS_ERR(led_cdev->dev)) {
6d71021a LH	519	mutex_unlock(&led_cdev->led_access);
f8a7c6fe	520	return PTR_ERR(led_cdev->dev);
6d71021a	521	}
495b8966 SV	522	if (init_data && init_data->fwnode)
495b8966 SV	523	device_set_node(led_cdev->dev, init_data->fwnode);
c72a1d60	524
0cb8eb30 HG	525	if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
	526	ret = led_add_brightness_hw_changed(led_cdev);
	527	if (ret) {
	528	device_unregister(led_cdev->dev);
1dbb9fb4	529	led_cdev->dev = NULL;
6d71021a	530	mutex_unlock(&led_cdev->led_access);
0cb8eb30 HG	531	return ret;
	532	}
	533	}
	534
a9c6ce57	535	led_cdev->work_flags = 0;
270c3957 RP	536	#ifdef CONFIG_LEDS_TRIGGERS
270c3957 RP	537	init_rwsem(&led_cdev->trigger_lock);
0cb8eb30 HG	538	#endif
	539	#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
	540	led_cdev->brightness_hw_changed = -1;
270c3957	541	#endif
c72a1d60	542	/* add to the list of leds */
72f8da32	543	down_write(&leds_list_lock);
c72a1d60	544	list_add_tail(&led_cdev->node, &leds_list);
72f8da32	545	up_write(&leds_list_lock);
c72a1d60	546
1bd465e6 GL	547	if (!led_cdev->max_brightness)
	548	led_cdev->max_brightness = LED_FULL;
	549
29d76dfa HMH	550	led_update_brightness(led_cdev);
29d76dfa HMH	551
757b06ae	552	led_init_core(led_cdev);
5ada28bf	553
c3bc9956	554	#ifdef CONFIG_LEDS_TRIGGERS
12fda168	555	led_trigger_set_default(led_cdev);
c3bc9956 RP	556	#endif
c3bc9956 RP	557
6d71021a LH	558	mutex_unlock(&led_cdev->led_access);
6d71021a LH	559
d23e7b8b	560	dev_dbg(parent, "Registered led device: %s\n",
f8a7c6fe	561	led_cdev->name);
c72a1d60 RP	562
	563	return 0;
	564	}
b2b998c0	565	EXPORT_SYMBOL_GPL(led_classdev_register_ext);
c72a1d60 RP	566
c72a1d60 RP	567	/**
0266a458	568	* led_classdev_unregister - unregisters a object of led_properties class.
70d63ccc	569	* @led_cdev: the led device to unregister
c72a1d60 RP	570	*
	571	* Unregisters a previously registered via led_classdev_register object.
	572	*/
b844eba2	573	void led_classdev_unregister(struct led_classdev *led_cdev)
c72a1d60	574	{
1dbb9fb4 AS	575	if (IS_ERR_OR_NULL(led_cdev->dev))
	576	return;
	577
c3bc9956	578	#ifdef CONFIG_LEDS_TRIGGERS
dc47206e	579	down_write(&led_cdev->trigger_lock);
c3bc9956 RP	580	if (led_cdev->trigger)
c3bc9956 RP	581	led_trigger_set(led_cdev, NULL);
dc47206e	582	up_write(&led_cdev->trigger_lock);
c3bc9956	583	#endif
c72a1d60	584
d84d80f3 HK	585	led_cdev->flags \|= LED_UNREGISTERING;
d84d80f3 HK	586
5ada28bf	587	/* Stop blinking */
d23a22a7	588	led_stop_software_blink(led_cdev);
d1aa577f	589
41906632 EJ	590	if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
41906632 EJ	591	led_set_brightness(led_cdev, LED_OFF);
5ada28bf	592
d1aa577f MK	593	flush_work(&led_cdev->set_brightness_work);
d1aa577f MK	594
0cb8eb30 HG	595	if (led_cdev->flags & LED_BRIGHT_HW_CHANGED)
	596	led_remove_brightness_hw_changed(led_cdev);
	597
b844eba2	598	device_unregister(led_cdev->dev);
c72a1d60	599
72f8da32	600	down_write(&leds_list_lock);
c72a1d60	601	list_del(&led_cdev->node);
72f8da32	602	up_write(&leds_list_lock);
acd899e4 JA	603
acd899e4 JA	604	mutex_destroy(&led_cdev->led_access);
c72a1d60	605	}
b844eba2	606	EXPORT_SYMBOL_GPL(led_classdev_unregister);
c72a1d60	607
ca1bb4ee BA	608	static void devm_led_classdev_release(struct device dev, void res)
	609	{
	610	led_classdev_unregister((struct led_classdev *)res);
	611	}
	612
	613	/**
b2b998c0	614	* devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
442c6098 RM	615	*
442c6098 RM	616	* @parent: parent of LED device
ca1bb4ee	617	* @led_cdev: the led_classdev structure for this device.
b2b998c0	618	* @init_data: LED class device initialization data
ca1bb4ee	619	*/
b2b998c0 JA	620	int devm_led_classdev_register_ext(struct device *parent,
	621	struct led_classdev *led_cdev,
	622	struct led_init_data *init_data)
ca1bb4ee BA	623	{
	624	struct led_classdev **dr;
	625	int rc;
	626
	627	dr = devres_alloc(devm_led_classdev_release, sizeof(*dr), GFP_KERNEL);
	628	if (!dr)
	629	return -ENOMEM;
	630
b2b998c0	631	rc = led_classdev_register_ext(parent, led_cdev, init_data);
ca1bb4ee BA	632	if (rc) {
	633	devres_free(dr);
	634	return rc;
	635	}
	636
	637	*dr = led_cdev;
	638	devres_add(parent, dr);
	639
	640	return 0;
	641	}
b2b998c0	642	EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
ca1bb4ee BA	643
	644	static int devm_led_classdev_match(struct device dev, void res, void *data)
	645	{
4b83cf07	646	struct led_classdev **p = res;
ca1bb4ee BA	647
	648	if (WARN_ON(!p \|\| !*p))
	649	return 0;
	650
	651	return *p == data;
	652	}
	653
	654	/**
	655	* devm_led_classdev_unregister() - resource managed led_classdev_unregister()
6a3a871b	656	* @dev: The device to unregister.
ca1bb4ee BA	657	* @led_cdev: the led_classdev structure for this device.
	658	*/
	659	void devm_led_classdev_unregister(struct device *dev,
	660	struct led_classdev *led_cdev)
	661	{
	662	WARN_ON(devres_release(dev,
	663	devm_led_classdev_release,
	664	devm_led_classdev_match, led_cdev));
	665	}
	666	EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
	667
c72a1d60 RP	668	static int __init leds_init(void)
c72a1d60 RP	669	{
43a707ae	670	return class_register(&leds_class);
c72a1d60 RP	671	}
	672
	673	static void __exit leds_exit(void)
	674	{
43a707ae	675	class_unregister(&leds_class);
c72a1d60 RP	676	}
	677
	678	subsys_initcall(leds_init);
	679	module_exit(leds_exit);
	680
	681	MODULE_AUTHOR("John Lenz, Richard Purdie");
	682	MODULE_LICENSE("GPL");
	683	MODULE_DESCRIPTION("LED Class Interface");