[deliverable/linux.git] / drivers / video / backlight / backlight.c

/*
 * Backlight Lowlevel Control Abstraction
 *
 * Copyright (C) 2003,2004 Hewlett-Packard Company
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/backlight.h>
#include <linux/notifier.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/fb.h>
#include <linux/slab.h>

#ifdef CONFIG_PMAC_BACKLIGHT
#include <asm/backlight.h>
#endif

static const char *const backlight_types[] = {
	[BACKLIGHT_RAW] = "raw",
	[BACKLIGHT_PLATFORM] = "platform",
	[BACKLIGHT_FIRMWARE] = "firmware",
};

#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
			   defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
/* This callback gets called when something important happens inside a
 * framebuffer driver. We're looking if that important event is blanking,
 * and if it is, we're switching backlight power as well ...
 */
static int fb_notifier_callback(struct notifier_block *self,
				unsigned long event, void *data)
{
	struct backlight_device *bd;
	struct fb_event *evdata = data;

	/* If we aren't interested in this event, skip it immediately ... */
	if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
		return 0;

	bd = container_of(self, struct backlight_device, fb_notif);
	mutex_lock(&bd->ops_lock);
	if (bd->ops)
		if (!bd->ops->check_fb ||
		    bd->ops->check_fb(bd, evdata->info)) {
			bd->props.fb_blank = *(int *)evdata->data;
			if (bd->props.fb_blank == FB_BLANK_UNBLANK)
				bd->props.state &= ~BL_CORE_FBBLANK;
			else
				bd->props.state |= BL_CORE_FBBLANK;
			backlight_update_status(bd);
		}
	mutex_unlock(&bd->ops_lock);
	return 0;
}

static int backlight_register_fb(struct backlight_device *bd)
{
	memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
	bd->fb_notif.notifier_call = fb_notifier_callback;

	return fb_register_client(&bd->fb_notif);
}

static void backlight_unregister_fb(struct backlight_device *bd)
{
	fb_unregister_client(&bd->fb_notif);
}
#else
static inline int backlight_register_fb(struct backlight_device *bd)
{
	return 0;
}

static inline void backlight_unregister_fb(struct backlight_device *bd)
{
}
#endif /* CONFIG_FB */

static void backlight_generate_event(struct backlight_device *bd,
				     enum backlight_update_reason reason)
{
	char *envp[2];

	switch (reason) {
	case BACKLIGHT_UPDATE_SYSFS:
		envp[0] = "SOURCE=sysfs";
		break;
	case BACKLIGHT_UPDATE_HOTKEY:
		envp[0] = "SOURCE=hotkey";
		break;
	default:
		envp[0] = "SOURCE=unknown";
		break;
	}
	envp[1] = NULL;
	kobject_uevent_env(&bd->dev.kobj, KOBJ_CHANGE, envp);
	sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness");
}

static ssize_t bl_power_show(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct backlight_device *bd = to_backlight_device(dev);

	return sprintf(buf, "%d\n", bd->props.power);
}

static ssize_t bl_power_store(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	int rc;
	struct backlight_device *bd = to_backlight_device(dev);
	unsigned long power;

	rc = kstrtoul(buf, 0, &power);
	if (rc)
		return rc;

	rc = -ENXIO;
	mutex_lock(&bd->ops_lock);
	if (bd->ops) {
		pr_debug("set power to %lu\n", power);
		if (bd->props.power != power) {
			bd->props.power = power;
			backlight_update_status(bd);
		}
		rc = count;
	}
	mutex_unlock(&bd->ops_lock);

	return rc;
}
static DEVICE_ATTR_RW(bl_power);

static ssize_t brightness_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct backlight_device *bd = to_backlight_device(dev);

	return sprintf(buf, "%d\n", bd->props.brightness);
}

static ssize_t brightness_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	int rc;
	struct backlight_device *bd = to_backlight_device(dev);
	unsigned long brightness;

	rc = kstrtoul(buf, 0, &brightness);
	if (rc)
		return rc;

	rc = -ENXIO;

	mutex_lock(&bd->ops_lock);
	if (bd->ops) {
		if (brightness > bd->props.max_brightness)
			rc = -EINVAL;
		else {
			pr_debug("set brightness to %lu\n", brightness);
			bd->props.brightness = brightness;
			backlight_update_status(bd);
			rc = count;
		}
	}
	mutex_unlock(&bd->ops_lock);

	backlight_generate_event(bd, BACKLIGHT_UPDATE_SYSFS);

	return rc;
}
static DEVICE_ATTR_RW(brightness);

static ssize_t type_show(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct backlight_device *bd = to_backlight_device(dev);

	return sprintf(buf, "%s\n", backlight_types[bd->props.type]);
}
static DEVICE_ATTR_RO(type);

static ssize_t max_brightness_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct backlight_device *bd = to_backlight_device(dev);

	return sprintf(buf, "%d\n", bd->props.max_brightness);
}
static DEVICE_ATTR_RO(max_brightness);

static ssize_t actual_brightness_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	int rc = -ENXIO;
	struct backlight_device *bd = to_backlight_device(dev);

	mutex_lock(&bd->ops_lock);
	if (bd->ops && bd->ops->get_brightness)
		rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
	mutex_unlock(&bd->ops_lock);

	return rc;
}
static DEVICE_ATTR_RO(actual_brightness);

static struct class *backlight_class;

#ifdef CONFIG_PM_SLEEP
static int backlight_suspend(struct device *dev)
{
	struct backlight_device *bd = to_backlight_device(dev);

	mutex_lock(&bd->ops_lock);
	if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
		bd->props.state |= BL_CORE_SUSPENDED;
		backlight_update_status(bd);
	}
	mutex_unlock(&bd->ops_lock);

	return 0;
}

static int backlight_resume(struct device *dev)
{
	struct backlight_device *bd = to_backlight_device(dev);

	mutex_lock(&bd->ops_lock);
	if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
		bd->props.state &= ~BL_CORE_SUSPENDED;
		backlight_update_status(bd);
	}
	mutex_unlock(&bd->ops_lock);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(backlight_class_dev_pm_ops, backlight_suspend,
			 backlight_resume);

static void bl_device_release(struct device *dev)
{
	struct backlight_device *bd = to_backlight_device(dev);
	kfree(bd);
}

static struct attribute *bl_device_attrs[] = {
	&dev_attr_bl_power.attr,
	&dev_attr_brightness.attr,
	&dev_attr_actual_brightness.attr,
	&dev_attr_max_brightness.attr,
	&dev_attr_type.attr,
	NULL,
};
ATTRIBUTE_GROUPS(bl_device);

/**
 * backlight_force_update - tell the backlight subsystem that hardware state
 *   has changed
 * @bd: the backlight device to update
 *
 * Updates the internal state of the backlight in response to a hardware event,
 * and generate a uevent to notify userspace
 */
void backlight_force_update(struct backlight_device *bd,
			    enum backlight_update_reason reason)
{
	mutex_lock(&bd->ops_lock);
	if (bd->ops && bd->ops->get_brightness)
		bd->props.brightness = bd->ops->get_brightness(bd);
	mutex_unlock(&bd->ops_lock);
	backlight_generate_event(bd, reason);
}
EXPORT_SYMBOL(backlight_force_update);

/**
 * backlight_device_register - create and register a new object of
 *   backlight_device class.
 * @name: the name of the new object(must be the same as the name of the
 *   respective framebuffer device).
 * @parent: a pointer to the parent device
 * @devdata: an optional pointer to be stored for private driver use. The
 *   methods may retrieve it by using bl_get_data(bd).
 * @ops: the backlight operations structure.
 *
 * Creates and registers new backlight device. Returns either an
 * ERR_PTR() or a pointer to the newly allocated device.
 */
struct backlight_device *backlight_device_register(const char *name,
	struct device *parent, void *devdata, const struct backlight_ops *ops,
	const struct backlight_properties *props)
{
	struct backlight_device *new_bd;
	int rc;

	pr_debug("backlight_device_register: name=%s\n", name);

	new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL);
	if (!new_bd)
		return ERR_PTR(-ENOMEM);

	mutex_init(&new_bd->update_lock);
	mutex_init(&new_bd->ops_lock);

	new_bd->dev.class = backlight_class;
	new_bd->dev.parent = parent;
	new_bd->dev.release = bl_device_release;
	dev_set_name(&new_bd->dev, "%s", name);
	dev_set_drvdata(&new_bd->dev, devdata);

	/* Set default properties */
	if (props) {
		memcpy(&new_bd->props, props,
		       sizeof(struct backlight_properties));
		if (props->type <= 0 || props->type >= BACKLIGHT_TYPE_MAX) {
			WARN(1, "%s: invalid backlight type", name);
			new_bd->props.type = BACKLIGHT_RAW;
		}
	} else {
		new_bd->props.type = BACKLIGHT_RAW;
	}

	rc = device_register(&new_bd->dev);
	if (rc) {
		kfree(new_bd);
		return ERR_PTR(rc);
	}

	rc = backlight_register_fb(new_bd);
	if (rc) {
		device_unregister(&new_bd->dev);
		return ERR_PTR(rc);
	}

	new_bd->ops = ops;

#ifdef CONFIG_PMAC_BACKLIGHT
	mutex_lock(&pmac_backlight_mutex);
	if (!pmac_backlight)
		pmac_backlight = new_bd;
	mutex_unlock(&pmac_backlight_mutex);
#endif

	return new_bd;
}
EXPORT_SYMBOL(backlight_device_register);

/**
 * backlight_device_unregister - unregisters a backlight device object.
 * @bd: the backlight device object to be unregistered and freed.
 *
 * Unregisters a previously registered via backlight_device_register object.
 */
void backlight_device_unregister(struct backlight_device *bd)
{
	if (!bd)
		return;

#ifdef CONFIG_PMAC_BACKLIGHT
	mutex_lock(&pmac_backlight_mutex);
	if (pmac_backlight == bd)
		pmac_backlight = NULL;
	mutex_unlock(&pmac_backlight_mutex);
#endif
	mutex_lock(&bd->ops_lock);
	bd->ops = NULL;
	mutex_unlock(&bd->ops_lock);

	backlight_unregister_fb(bd);
	device_unregister(&bd->dev);
}
EXPORT_SYMBOL(backlight_device_unregister);

static void devm_backlight_device_release(struct device *dev, void *res)
{
	struct backlight_device *backlight = *(struct backlight_device **)res;

	backlight_device_unregister(backlight);
}

static int devm_backlight_device_match(struct device *dev, void *res,
					void *data)
{
	struct backlight_device **r = res;

	return *r == data;
}

/**
 * devm_backlight_device_register - resource managed backlight_device_register()
 * @dev: the device to register
 * @name: the name of the device
 * @parent: a pointer to the parent device
 * @devdata: an optional pointer to be stored for private driver use
 * @ops: the backlight operations structure
 * @props: the backlight properties
 *
 * @return a struct backlight on success, or an ERR_PTR on error
 *
 * Managed backlight_device_register(). The backlight_device returned
 * from this function are automatically freed on driver detach.
 * See backlight_device_register() for more information.
 */
struct backlight_device *devm_backlight_device_register(struct device *dev,
	const char *name, struct device *parent, void *devdata,
	const struct backlight_ops *ops,
	const struct backlight_properties *props)
{
	struct backlight_device **ptr, *backlight;

	ptr = devres_alloc(devm_backlight_device_release, sizeof(*ptr),
			GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	backlight = backlight_device_register(name, parent, devdata, ops,
						props);
	if (!IS_ERR(backlight)) {
		*ptr = backlight;
		devres_add(dev, ptr);
	} else {
		devres_free(ptr);
	}

	return backlight;
}
EXPORT_SYMBOL(devm_backlight_device_register);

/**
 * devm_backlight_device_unregister - resource managed backlight_device_unregister()
 * @dev: the device to unregister
 * @bd: the backlight device to unregister
 *
 * Deallocated a backlight allocated with devm_backlight_device_register().
 * Normally this function will not need to be called and the resource management
 * code will ensure that the resource is freed.
 */
void devm_backlight_device_unregister(struct device *dev,
				struct backlight_device *bd)
{
	int rc;

	rc = devres_release(dev, devm_backlight_device_release,
				devm_backlight_device_match, bd);
	WARN_ON(rc);
}
EXPORT_SYMBOL(devm_backlight_device_unregister);

#ifdef CONFIG_OF
static int of_parent_match(struct device *dev, const void *data)
{
	return dev->parent && dev->parent->of_node == data;
}

/**
 * of_find_backlight_by_node() - find backlight device by device-tree node
 * @node: device-tree node of the backlight device
 *
 * Returns a pointer to the backlight device corresponding to the given DT
 * node or NULL if no such backlight device exists or if the device hasn't
 * been probed yet.
 *
 * This function obtains a reference on the backlight device and it is the
 * caller's responsibility to drop the reference by calling put_device() on
 * the backlight device's .dev field.
 */
struct backlight_device *of_find_backlight_by_node(struct device_node *node)
{
	struct device *dev;

	dev = class_find_device(backlight_class, NULL, node, of_parent_match);

	return dev ? to_backlight_device(dev) : NULL;
}
EXPORT_SYMBOL(of_find_backlight_by_node);
#endif

static void __exit backlight_class_exit(void)
{
	class_destroy(backlight_class);
}

static int __init backlight_class_init(void)
{
	backlight_class = class_create(THIS_MODULE, "backlight");
	if (IS_ERR(backlight_class)) {
		pr_warn("Unable to create backlight class; errno = %ld\n",
			PTR_ERR(backlight_class));
		return PTR_ERR(backlight_class);
	}

	backlight_class->dev_groups = bl_device_groups;
	backlight_class->pm = &backlight_class_dev_pm_ops;
	return 0;
}

/*
 * if this is compiled into the kernel, we need to ensure that the
 * class is registered before users of the class try to register lcd's
 */
postcore_initcall(backlight_class_init);
module_exit(backlight_class_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Backlight Lowlevel Control Abstraction
	3	*
	4	* Copyright (C) 2003,2004 Hewlett-Packard Company
	5	*
	6	*/
	7
35f96162 JH	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35f96162 JH	9
1da177e4 LT	10	#include <linux/module.h>
	11	#include <linux/init.h>
	12	#include <linux/device.h>
	13	#include <linux/backlight.h>
	14	#include <linux/notifier.h>
	15	#include <linux/ctype.h>
	16	#include <linux/err.h>
	17	#include <linux/fb.h>
5a0e3ad6	18	#include <linux/slab.h>
1da177e4	19
321709c5 RP	20	#ifdef CONFIG_PMAC_BACKLIGHT
	21	#include <asm/backlight.h>
	22	#endif
3d5eeadd	23
c338bfb5	24	static const char *const backlight_types[] = {
bb7ca747 MG	25	[BACKLIGHT_RAW] = "raw",
	26	[BACKLIGHT_PLATFORM] = "platform",
	27	[BACKLIGHT_FIRMWARE] = "firmware",
	28	};
	29
3d5eeadd JS	30	#if defined(CONFIG_FB) \|\| (defined(CONFIG_FB_MODULE) && \
	31	defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
	32	/* This callback gets called when something important happens inside a
	33	* framebuffer driver. We're looking if that important event is blanking,
	34	* and if it is, we're switching backlight power as well ...
	35	*/
	36	static int fb_notifier_callback(struct notifier_block *self,
	37	unsigned long event, void *data)
	38	{
	39	struct backlight_device *bd;
	40	struct fb_event *evdata = data;
	41
	42	/* If we aren't interested in this event, skip it immediately ... */
994efacd	43	if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
3d5eeadd JS	44	return 0;
	45
	46	bd = container_of(self, struct backlight_device, fb_notif);
599a52d1 RP	47	mutex_lock(&bd->ops_lock);
	48	if (bd->ops)
	49	if (!bd->ops->check_fb \|\|
57e148b6	50	bd->ops->check_fb(bd, evdata->info)) {
599a52d1	51	bd->props.fb_blank = (int )evdata->data;
c835ee7f RP	52	if (bd->props.fb_blank == FB_BLANK_UNBLANK)
	53	bd->props.state &= ~BL_CORE_FBBLANK;
	54	else
	55	bd->props.state \|= BL_CORE_FBBLANK;
28ee086d	56	backlight_update_status(bd);
3d5eeadd	57	}
599a52d1	58	mutex_unlock(&bd->ops_lock);
3d5eeadd JS	59	return 0;
	60	}
	61
	62	static int backlight_register_fb(struct backlight_device *bd)
	63	{
	64	memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
	65	bd->fb_notif.notifier_call = fb_notifier_callback;
	66
	67	return fb_register_client(&bd->fb_notif);
	68	}
	69
	70	static void backlight_unregister_fb(struct backlight_device *bd)
	71	{
	72	fb_unregister_client(&bd->fb_notif);
	73	}
	74	#else
	75	static inline int backlight_register_fb(struct backlight_device *bd)
	76	{
	77	return 0;
	78	}
	79
	80	static inline void backlight_unregister_fb(struct backlight_device *bd)
	81	{
	82	}
	83	#endif /* CONFIG_FB */
	84
325253a6 MG	85	static void backlight_generate_event(struct backlight_device *bd,
	86	enum backlight_update_reason reason)
	87	{
	88	char *envp[2];
	89
	90	switch (reason) {
	91	case BACKLIGHT_UPDATE_SYSFS:
	92	envp[0] = "SOURCE=sysfs";
	93	break;
	94	case BACKLIGHT_UPDATE_HOTKEY:
	95	envp[0] = "SOURCE=hotkey";
	96	break;
	97	default:
	98	envp[0] = "SOURCE=unknown";
	99	break;
	100	}
	101	envp[1] = NULL;
	102	kobject_uevent_env(&bd->dev.kobj, KOBJ_CHANGE, envp);
89dfc28c	103	sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness");
325253a6 MG	104	}
325253a6 MG	105
ea1bb706 GKH	106	static ssize_t bl_power_show(struct device dev, struct device_attribute attr,
ea1bb706 GKH	107	char *buf)
1da177e4	108	{
655bfd7a	109	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	110
599a52d1	111	return sprintf(buf, "%d\n", bd->props.power);
1da177e4 LT	112	}
1da177e4 LT	113
ea1bb706 GKH	114	static ssize_t bl_power_store(struct device dev, struct device_attribute attr,
ea1bb706 GKH	115	const char *buf, size_t count)
1da177e4	116	{
9a2c61a9	117	int rc;
655bfd7a	118	struct backlight_device *bd = to_backlight_device(dev);
9a2c61a9	119	unsigned long power;
1da177e4	120
66655760	121	rc = kstrtoul(buf, 0, &power);
9a2c61a9 PM	122	if (rc)
9a2c61a9 PM	123	return rc;
1da177e4	124
9a2c61a9	125	rc = -ENXIO;
599a52d1 RP	126	mutex_lock(&bd->ops_lock);
599a52d1 RP	127	if (bd->ops) {
35f96162	128	pr_debug("set power to %lu\n", power);
51552453 HD	129	if (bd->props.power != power) {
	130	bd->props.power = power;
	131	backlight_update_status(bd);
	132	}
1da177e4	133	rc = count;
6ca01765	134	}
599a52d1	135	mutex_unlock(&bd->ops_lock);
1da177e4 LT	136
	137	return rc;
	138	}
ea1bb706	139	static DEVICE_ATTR_RW(bl_power);
1da177e4	140
ea1bb706	141	static ssize_t brightness_show(struct device *dev,
655bfd7a	142	struct device_attribute attr, char buf)
1da177e4	143	{
655bfd7a	144	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	145
599a52d1	146	return sprintf(buf, "%d\n", bd->props.brightness);
1da177e4 LT	147	}
1da177e4 LT	148
ea1bb706	149	static ssize_t brightness_store(struct device *dev,
655bfd7a	150	struct device_attribute attr, const char buf, size_t count)
1da177e4	151	{
9a2c61a9	152	int rc;
655bfd7a	153	struct backlight_device *bd = to_backlight_device(dev);
9a2c61a9	154	unsigned long brightness;
1da177e4	155
66655760	156	rc = kstrtoul(buf, 0, &brightness);
9a2c61a9 PM	157	if (rc)
	158	return rc;
	159
	160	rc = -ENXIO;
1da177e4	161
599a52d1 RP	162	mutex_lock(&bd->ops_lock);
	163	if (bd->ops) {
	164	if (brightness > bd->props.max_brightness)
6ca01765 RP	165	rc = -EINVAL;
6ca01765 RP	166	else {
35f96162	167	pr_debug("set brightness to %lu\n", brightness);
9be1df98 ZR	168	bd->props.brightness = brightness;
9be1df98 ZR	169	backlight_update_status(bd);
6ca01765 RP	170	rc = count;
	171	}
	172	}
599a52d1	173	mutex_unlock(&bd->ops_lock);
1da177e4	174
325253a6 MG	175	backlight_generate_event(bd, BACKLIGHT_UPDATE_SYSFS);
325253a6 MG	176
1da177e4 LT	177	return rc;
1da177e4 LT	178	}
ea1bb706	179	static DEVICE_ATTR_RW(brightness);
1da177e4	180
ea1bb706 GKH	181	static ssize_t type_show(struct device dev, struct device_attribute attr,
ea1bb706 GKH	182	char *buf)
bb7ca747 MG	183	{
	184	struct backlight_device *bd = to_backlight_device(dev);
	185
	186	return sprintf(buf, "%s\n", backlight_types[bd->props.type]);
	187	}
ea1bb706	188	static DEVICE_ATTR_RO(type);
bb7ca747	189
ea1bb706	190	static ssize_t max_brightness_show(struct device *dev,
655bfd7a	191	struct device_attribute attr, char buf)
1da177e4	192	{
655bfd7a	193	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	194
599a52d1	195	return sprintf(buf, "%d\n", bd->props.max_brightness);
6ca01765	196	}
ea1bb706	197	static DEVICE_ATTR_RO(max_brightness);
6ca01765	198
ea1bb706	199	static ssize_t actual_brightness_show(struct device *dev,
655bfd7a	200	struct device_attribute attr, char buf)
6ca01765 RP	201	{
6ca01765 RP	202	int rc = -ENXIO;
655bfd7a	203	struct backlight_device *bd = to_backlight_device(dev);
6ca01765	204
599a52d1 RP	205	mutex_lock(&bd->ops_lock);
	206	if (bd->ops && bd->ops->get_brightness)
	207	rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
	208	mutex_unlock(&bd->ops_lock);
1da177e4 LT	209
	210	return rc;
	211	}
ea1bb706	212	static DEVICE_ATTR_RO(actual_brightness);
1da177e4	213
0ad90efd	214	static struct class *backlight_class;
655bfd7a	215
3601792e SK	216	#ifdef CONFIG_PM_SLEEP
3601792e SK	217	static int backlight_suspend(struct device *dev)
c835ee7f RP	218	{
	219	struct backlight_device *bd = to_backlight_device(dev);
	220
d1d73578 UKK	221	mutex_lock(&bd->ops_lock);
d1d73578 UKK	222	if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
c835ee7f RP	223	bd->props.state \|= BL_CORE_SUSPENDED;
c835ee7f RP	224	backlight_update_status(bd);
c835ee7f	225	}
d1d73578	226	mutex_unlock(&bd->ops_lock);
c835ee7f RP	227
	228	return 0;
	229	}
	230
	231	static int backlight_resume(struct device *dev)
	232	{
	233	struct backlight_device *bd = to_backlight_device(dev);
	234
d1d73578 UKK	235	mutex_lock(&bd->ops_lock);
d1d73578 UKK	236	if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
c835ee7f RP	237	bd->props.state &= ~BL_CORE_SUSPENDED;
c835ee7f RP	238	backlight_update_status(bd);
c835ee7f	239	}
d1d73578	240	mutex_unlock(&bd->ops_lock);
c835ee7f RP	241
	242	return 0;
	243	}
3601792e SK	244	#endif
	245
	246	static SIMPLE_DEV_PM_OPS(backlight_class_dev_pm_ops, backlight_suspend,
	247	backlight_resume);
c835ee7f	248
655bfd7a	249	static void bl_device_release(struct device *dev)
1da177e4 LT	250	{
	251	struct backlight_device *bd = to_backlight_device(dev);
	252	kfree(bd);
	253	}
	254
ea1bb706 GKH	255	static struct attribute *bl_device_attrs[] = {
	256	&dev_attr_bl_power.attr,
	257	&dev_attr_brightness.attr,
	258	&dev_attr_actual_brightness.attr,
	259	&dev_attr_max_brightness.attr,
	260	&dev_attr_type.attr,
	261	NULL,
1da177e4	262	};
ea1bb706	263	ATTRIBUTE_GROUPS(bl_device);
1da177e4	264
325253a6 MG	265	/**
	266	* backlight_force_update - tell the backlight subsystem that hardware state
	267	* has changed
	268	* @bd: the backlight device to update
	269	*
	270	* Updates the internal state of the backlight in response to a hardware event,
	271	* and generate a uevent to notify userspace
	272	*/
	273	void backlight_force_update(struct backlight_device *bd,
	274	enum backlight_update_reason reason)
	275	{
	276	mutex_lock(&bd->ops_lock);
	277	if (bd->ops && bd->ops->get_brightness)
	278	bd->props.brightness = bd->ops->get_brightness(bd);
	279	mutex_unlock(&bd->ops_lock);
	280	backlight_generate_event(bd, reason);
	281	}
	282	EXPORT_SYMBOL(backlight_force_update);
	283
1da177e4 LT	284	/**
	285	* backlight_device_register - create and register a new object of
	286	* backlight_device class.
	287	* @name: the name of the new object(must be the same as the name of the
	288	* respective framebuffer device).
f6ec2d96	289	* @parent: a pointer to the parent device
655bfd7a RP	290	* @devdata: an optional pointer to be stored for private driver use. The
655bfd7a RP	291	* methods may retrieve it by using bl_get_data(bd).
599a52d1	292	* @ops: the backlight operations structure.
1da177e4	293	*
655bfd7a	294	* Creates and registers new backlight device. Returns either an
1da177e4 LT	295	* ERR_PTR() or a pointer to the newly allocated device.
1da177e4 LT	296	*/
519ab5f2	297	struct backlight_device backlight_device_register(const char name,
a19a6ee6 MG	298	struct device parent, void devdata, const struct backlight_ops *ops,
a19a6ee6 MG	299	const struct backlight_properties *props)
1da177e4	300	{
1da177e4	301	struct backlight_device *new_bd;
655bfd7a	302	int rc;
1da177e4	303
655bfd7a	304	pr_debug("backlight_device_register: name=%s\n", name);
1da177e4	305
599a52d1	306	new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL);
90968e8e	307	if (!new_bd)
10ad1b73	308	return ERR_PTR(-ENOMEM);
1da177e4	309
28ee086d	310	mutex_init(&new_bd->update_lock);
599a52d1	311	mutex_init(&new_bd->ops_lock);
1da177e4	312
655bfd7a RP	313	new_bd->dev.class = backlight_class;
	314	new_bd->dev.parent = parent;
	315	new_bd->dev.release = bl_device_release;
02aa2a37	316	dev_set_name(&new_bd->dev, "%s", name);
655bfd7a RP	317	dev_set_drvdata(&new_bd->dev, devdata);
655bfd7a RP	318
a19a6ee6	319	/* Set default properties */
bb7ca747	320	if (props) {
a19a6ee6 MG	321	memcpy(&new_bd->props, props,
a19a6ee6 MG	322	sizeof(struct backlight_properties));
bb7ca747 MG	323	if (props->type <= 0 \|\| props->type >= BACKLIGHT_TYPE_MAX) {
	324	WARN(1, "%s: invalid backlight type", name);
	325	new_bd->props.type = BACKLIGHT_RAW;
	326	}
	327	} else {
	328	new_bd->props.type = BACKLIGHT_RAW;
	329	}
a19a6ee6	330
655bfd7a	331	rc = device_register(&new_bd->dev);
90968e8e	332	if (rc) {
2fd5a154	333	kfree(new_bd);
1da177e4 LT	334	return ERR_PTR(rc);
	335	}
	336
3d5eeadd	337	rc = backlight_register_fb(new_bd);
2fd5a154	338	if (rc) {
655bfd7a	339	device_unregister(&new_bd->dev);
2fd5a154 DT	340	return ERR_PTR(rc);
	341	}
	342
655bfd7a	343	new_bd->ops = ops;
1da177e4	344
321709c5 RP	345	#ifdef CONFIG_PMAC_BACKLIGHT
	346	mutex_lock(&pmac_backlight_mutex);
	347	if (!pmac_backlight)
	348	pmac_backlight = new_bd;
	349	mutex_unlock(&pmac_backlight_mutex);
	350	#endif
	351
1da177e4 LT	352	return new_bd;
	353	}
	354	EXPORT_SYMBOL(backlight_device_register);
	355
	356	/**
	357	* backlight_device_unregister - unregisters a backlight device object.
	358	* @bd: the backlight device object to be unregistered and freed.
	359	*
	360	* Unregisters a previously registered via backlight_device_register object.
	361	*/
	362	void backlight_device_unregister(struct backlight_device *bd)
	363	{
1da177e4 LT	364	if (!bd)
	365	return;
	366
321709c5 RP	367	#ifdef CONFIG_PMAC_BACKLIGHT
	368	mutex_lock(&pmac_backlight_mutex);
	369	if (pmac_backlight == bd)
	370	pmac_backlight = NULL;
	371	mutex_unlock(&pmac_backlight_mutex);
	372	#endif
599a52d1 RP	373	mutex_lock(&bd->ops_lock);
	374	bd->ops = NULL;
	375	mutex_unlock(&bd->ops_lock);
1da177e4	376
3d5eeadd	377	backlight_unregister_fb(bd);
655bfd7a	378	device_unregister(&bd->dev);
1da177e4 LT	379	}
	380	EXPORT_SYMBOL(backlight_device_unregister);
	381
8318fde4 JH	382	static void devm_backlight_device_release(struct device dev, void res)
	383	{
	384	struct backlight_device backlight = (struct backlight_device **)res;
	385
	386	backlight_device_unregister(backlight);
	387	}
	388
	389	static int devm_backlight_device_match(struct device dev, void res,
	390	void *data)
	391	{
	392	struct backlight_device **r = res;
	393
	394	return *r == data;
	395	}
	396
	397	/**
	398	* devm_backlight_device_register - resource managed backlight_device_register()
	399	* @dev: the device to register
	400	* @name: the name of the device
	401	* @parent: a pointer to the parent device
	402	* @devdata: an optional pointer to be stored for private driver use
	403	* @ops: the backlight operations structure
	404	* @props: the backlight properties
	405	*
	406	* @return a struct backlight on success, or an ERR_PTR on error
	407	*
	408	* Managed backlight_device_register(). The backlight_device returned
	409	* from this function are automatically freed on driver detach.
	410	* See backlight_device_register() for more information.
	411	*/
	412	struct backlight_device devm_backlight_device_register(struct device dev,
	413	const char name, struct device parent, void *devdata,
	414	const struct backlight_ops *ops,
	415	const struct backlight_properties *props)
	416	{
	417	struct backlight_device *ptr, backlight;
	418
	419	ptr = devres_alloc(devm_backlight_device_release, sizeof(*ptr),
	420	GFP_KERNEL);
	421	if (!ptr)
	422	return ERR_PTR(-ENOMEM);
	423
	424	backlight = backlight_device_register(name, parent, devdata, ops,
	425	props);
	426	if (!IS_ERR(backlight)) {
	427	*ptr = backlight;
	428	devres_add(dev, ptr);
	429	} else {
	430	devres_free(ptr);
	431	}
	432
	433	return backlight;
	434	}
	435	EXPORT_SYMBOL(devm_backlight_device_register);
	436
	437	/**
	438	* devm_backlight_device_unregister - resource managed backlight_device_unregister()
	439	* @dev: the device to unregister
	440	* @bd: the backlight device to unregister
	441	*
	442	* Deallocated a backlight allocated with devm_backlight_device_register().
	443	* Normally this function will not need to be called and the resource management
	444	* code will ensure that the resource is freed.
	445	*/
446	void devm_backlight_device_unregister(struct device *dev,
447	struct backlight_device *bd)
448	{
449	int rc;
450
451	rc = devres_release(dev, devm_backlight_device_release,
452	devm_backlight_device_match, bd);
453	WARN_ON(rc);
454	}
455	EXPORT_SYMBOL(devm_backlight_device_unregister);
456
762a936f	457	#ifdef CONFIG_OF
3213f631	458	static int of_parent_match(struct device dev, const void data)
762a936f TR	459	{
	460	return dev->parent && dev->parent->of_node == data;
	461	}
	462
	463	/**
	464	* of_find_backlight_by_node() - find backlight device by device-tree node
	465	* @node: device-tree node of the backlight device
	466	*
	467	* Returns a pointer to the backlight device corresponding to the given DT
	468	* node or NULL if no such backlight device exists or if the device hasn't
	469	* been probed yet.
	470	*
	471	* This function obtains a reference on the backlight device and it is the
	472	* caller's responsibility to drop the reference by calling put_device() on
	473	* the backlight device's .dev field.
	474	*/
	475	struct backlight_device of_find_backlight_by_node(struct device_node node)
	476	{
	477	struct device *dev;
	478
	479	dev = class_find_device(backlight_class, NULL, node, of_parent_match);
	480
	481	return dev ? to_backlight_device(dev) : NULL;
	482	}
	483	EXPORT_SYMBOL(of_find_backlight_by_node);
	484	#endif
	485
1da177e4 LT	486	static void __exit backlight_class_exit(void)
1da177e4 LT	487	{
655bfd7a	488	class_destroy(backlight_class);
1da177e4 LT	489	}
	490
	491	static int __init backlight_class_init(void)
	492	{
655bfd7a RP	493	backlight_class = class_create(THIS_MODULE, "backlight");
655bfd7a RP	494	if (IS_ERR(backlight_class)) {
35f96162 JH	495	pr_warn("Unable to create backlight class; errno = %ld\n",
35f96162 JH	496	PTR_ERR(backlight_class));
655bfd7a RP	497	return PTR_ERR(backlight_class);
	498	}
	499
ea1bb706	500	backlight_class->dev_groups = bl_device_groups;
3601792e	501	backlight_class->pm = &backlight_class_dev_pm_ops;
655bfd7a	502	return 0;
1da177e4 LT	503	}
	504
	505	/*
	506	* if this is compiled into the kernel, we need to ensure that the
	507	* class is registered before users of the class try to register lcd's
	508	*/
	509	postcore_initcall(backlight_class_init);
	510	module_exit(backlight_class_exit);
	511
	512	MODULE_LICENSE("GPL");
	513	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	514	MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");