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

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

#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 backlight_show_power(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 backlight_store_power(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("backlight: 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 ssize_t backlight_show_brightness(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 backlight_store_brightness(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("backlight: 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 ssize_t backlight_show_type(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 ssize_t backlight_show_max_brightness(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 ssize_t backlight_show_actual_brightness(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 struct class *backlight_class;

static int backlight_suspend(struct device *dev, pm_message_t state)
{
	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;
}

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

static struct device_attribute bl_device_attributes[] = {
	__ATTR(bl_power, 0644, backlight_show_power, backlight_store_power),
	__ATTR(brightness, 0644, backlight_show_brightness,
		     backlight_store_brightness),
	__ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
		     NULL),
	__ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
	__ATTR(type, 0444, backlight_show_type, NULL),
	__ATTR_NULL,
};

/**
 * 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, 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 __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)) {
		printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
				PTR_ERR(backlight_class));
		return PTR_ERR(backlight_class);
	}

	backlight_class->dev_attrs = bl_device_attributes;
	backlight_class->suspend = backlight_suspend;
	backlight_class->resume = backlight_resume;
	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
1da177e4 LT	8	#include <linux/module.h>
	9	#include <linux/init.h>
	10	#include <linux/device.h>
	11	#include <linux/backlight.h>
	12	#include <linux/notifier.h>
	13	#include <linux/ctype.h>
	14	#include <linux/err.h>
	15	#include <linux/fb.h>
5a0e3ad6	16	#include <linux/slab.h>
1da177e4	17
321709c5 RP	18	#ifdef CONFIG_PMAC_BACKLIGHT
	19	#include <asm/backlight.h>
	20	#endif
3d5eeadd	21
c338bfb5	22	static const char *const backlight_types[] = {
bb7ca747 MG	23	[BACKLIGHT_RAW] = "raw",
	24	[BACKLIGHT_PLATFORM] = "platform",
	25	[BACKLIGHT_FIRMWARE] = "firmware",
	26	};
	27
3d5eeadd JS	28	#if defined(CONFIG_FB) \|\| (defined(CONFIG_FB_MODULE) && \
	29	defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
	30	/* This callback gets called when something important happens inside a
	31	* framebuffer driver. We're looking if that important event is blanking,
	32	* and if it is, we're switching backlight power as well ...
	33	*/
	34	static int fb_notifier_callback(struct notifier_block *self,
	35	unsigned long event, void *data)
	36	{
	37	struct backlight_device *bd;
	38	struct fb_event *evdata = data;
	39
	40	/* If we aren't interested in this event, skip it immediately ... */
994efacd	41	if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
3d5eeadd JS	42	return 0;
	43
	44	bd = container_of(self, struct backlight_device, fb_notif);
599a52d1 RP	45	mutex_lock(&bd->ops_lock);
	46	if (bd->ops)
	47	if (!bd->ops->check_fb \|\|
57e148b6	48	bd->ops->check_fb(bd, evdata->info)) {
599a52d1	49	bd->props.fb_blank = (int )evdata->data;
c835ee7f RP	50	if (bd->props.fb_blank == FB_BLANK_UNBLANK)
	51	bd->props.state &= ~BL_CORE_FBBLANK;
	52	else
	53	bd->props.state \|= BL_CORE_FBBLANK;
28ee086d	54	backlight_update_status(bd);
3d5eeadd	55	}
599a52d1	56	mutex_unlock(&bd->ops_lock);
3d5eeadd JS	57	return 0;
	58	}
	59
	60	static int backlight_register_fb(struct backlight_device *bd)
	61	{
	62	memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
	63	bd->fb_notif.notifier_call = fb_notifier_callback;
	64
	65	return fb_register_client(&bd->fb_notif);
	66	}
	67
	68	static void backlight_unregister_fb(struct backlight_device *bd)
	69	{
	70	fb_unregister_client(&bd->fb_notif);
	71	}
	72	#else
	73	static inline int backlight_register_fb(struct backlight_device *bd)
	74	{
	75	return 0;
	76	}
	77
	78	static inline void backlight_unregister_fb(struct backlight_device *bd)
	79	{
	80	}
	81	#endif /* CONFIG_FB */
	82
325253a6 MG	83	static void backlight_generate_event(struct backlight_device *bd,
	84	enum backlight_update_reason reason)
	85	{
	86	char *envp[2];
	87
	88	switch (reason) {
	89	case BACKLIGHT_UPDATE_SYSFS:
	90	envp[0] = "SOURCE=sysfs";
	91	break;
	92	case BACKLIGHT_UPDATE_HOTKEY:
	93	envp[0] = "SOURCE=hotkey";
	94	break;
	95	default:
	96	envp[0] = "SOURCE=unknown";
	97	break;
	98	}
	99	envp[1] = NULL;
	100	kobject_uevent_env(&bd->dev.kobj, KOBJ_CHANGE, envp);
89dfc28c	101	sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness");
325253a6 MG	102	}
325253a6 MG	103
655bfd7a	104	static ssize_t backlight_show_power(struct device *dev,
66655760	105	struct device_attribute attr, char buf)
1da177e4	106	{
655bfd7a	107	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	108
599a52d1	109	return sprintf(buf, "%d\n", bd->props.power);
1da177e4 LT	110	}
1da177e4 LT	111
655bfd7a RP	112	static ssize_t backlight_store_power(struct device *dev,
655bfd7a RP	113	struct device_attribute attr, const char buf, size_t count)
1da177e4	114	{
9a2c61a9	115	int rc;
655bfd7a	116	struct backlight_device *bd = to_backlight_device(dev);
9a2c61a9	117	unsigned long power;
1da177e4	118
66655760	119	rc = kstrtoul(buf, 0, &power);
9a2c61a9 PM	120	if (rc)
9a2c61a9 PM	121	return rc;
1da177e4	122
9a2c61a9	123	rc = -ENXIO;
599a52d1 RP	124	mutex_lock(&bd->ops_lock);
599a52d1 RP	125	if (bd->ops) {
9a2c61a9	126	pr_debug("backlight: set power to %lu\n", power);
51552453 HD	127	if (bd->props.power != power) {
	128	bd->props.power = power;
	129	backlight_update_status(bd);
	130	}
1da177e4	131	rc = count;
6ca01765	132	}
599a52d1	133	mutex_unlock(&bd->ops_lock);
1da177e4 LT	134
	135	return rc;
	136	}
	137
655bfd7a RP	138	static ssize_t backlight_show_brightness(struct device *dev,
655bfd7a RP	139	struct device_attribute attr, char buf)
1da177e4	140	{
655bfd7a	141	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	142
599a52d1	143	return sprintf(buf, "%d\n", bd->props.brightness);
1da177e4 LT	144	}
1da177e4 LT	145
655bfd7a RP	146	static ssize_t backlight_store_brightness(struct device *dev,
655bfd7a RP	147	struct device_attribute attr, const char buf, size_t count)
1da177e4	148	{
9a2c61a9	149	int rc;
655bfd7a	150	struct backlight_device *bd = to_backlight_device(dev);
9a2c61a9	151	unsigned long brightness;
1da177e4	152
66655760	153	rc = kstrtoul(buf, 0, &brightness);
9a2c61a9 PM	154	if (rc)
	155	return rc;
	156
	157	rc = -ENXIO;
1da177e4	158
599a52d1 RP	159	mutex_lock(&bd->ops_lock);
	160	if (bd->ops) {
	161	if (brightness > bd->props.max_brightness)
6ca01765 RP	162	rc = -EINVAL;
6ca01765 RP	163	else {
9a2c61a9	164	pr_debug("backlight: set brightness to %lu\n",
6ca01765	165	brightness);
9be1df98 ZR	166	bd->props.brightness = brightness;
9be1df98 ZR	167	backlight_update_status(bd);
6ca01765 RP	168	rc = count;
	169	}
	170	}
599a52d1	171	mutex_unlock(&bd->ops_lock);
1da177e4	172
325253a6 MG	173	backlight_generate_event(bd, BACKLIGHT_UPDATE_SYSFS);
325253a6 MG	174
1da177e4 LT	175	return rc;
	176	}
	177
bb7ca747 MG	178	static ssize_t backlight_show_type(struct device *dev,
	179	struct device_attribute attr, char buf)
	180	{
	181	struct backlight_device *bd = to_backlight_device(dev);
	182
	183	return sprintf(buf, "%s\n", backlight_types[bd->props.type]);
	184	}
	185
655bfd7a RP	186	static ssize_t backlight_show_max_brightness(struct device *dev,
655bfd7a RP	187	struct device_attribute attr, char buf)
1da177e4	188	{
655bfd7a	189	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	190
599a52d1	191	return sprintf(buf, "%d\n", bd->props.max_brightness);
6ca01765 RP	192	}
6ca01765 RP	193
655bfd7a RP	194	static ssize_t backlight_show_actual_brightness(struct device *dev,
655bfd7a RP	195	struct device_attribute attr, char buf)
6ca01765 RP	196	{
6ca01765 RP	197	int rc = -ENXIO;
655bfd7a	198	struct backlight_device *bd = to_backlight_device(dev);
6ca01765	199
599a52d1 RP	200	mutex_lock(&bd->ops_lock);
	201	if (bd->ops && bd->ops->get_brightness)
	202	rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
	203	mutex_unlock(&bd->ops_lock);
1da177e4 LT	204
	205	return rc;
	206	}
	207
0ad90efd	208	static struct class *backlight_class;
655bfd7a	209
c835ee7f RP	210	static int backlight_suspend(struct device *dev, pm_message_t state)
	211	{
	212	struct backlight_device *bd = to_backlight_device(dev);
	213
d1d73578 UKK	214	mutex_lock(&bd->ops_lock);
d1d73578 UKK	215	if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
c835ee7f RP	216	bd->props.state \|= BL_CORE_SUSPENDED;
c835ee7f RP	217	backlight_update_status(bd);
c835ee7f	218	}
d1d73578	219	mutex_unlock(&bd->ops_lock);
c835ee7f RP	220
	221	return 0;
	222	}
	223
	224	static int backlight_resume(struct device *dev)
	225	{
	226	struct backlight_device *bd = to_backlight_device(dev);
	227
d1d73578 UKK	228	mutex_lock(&bd->ops_lock);
d1d73578 UKK	229	if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) {
c835ee7f RP	230	bd->props.state &= ~BL_CORE_SUSPENDED;
c835ee7f RP	231	backlight_update_status(bd);
c835ee7f	232	}
d1d73578	233	mutex_unlock(&bd->ops_lock);
c835ee7f RP	234
	235	return 0;
	236	}
	237
655bfd7a	238	static void bl_device_release(struct device *dev)
1da177e4 LT	239	{
	240	struct backlight_device *bd = to_backlight_device(dev);
	241	kfree(bd);
	242	}
	243
655bfd7a RP	244	static struct device_attribute bl_device_attributes[] = {
	245	__ATTR(bl_power, 0644, backlight_show_power, backlight_store_power),
	246	__ATTR(brightness, 0644, backlight_show_brightness,
6ca01765	247	backlight_store_brightness),
655bfd7a	248	__ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
6ca01765	249	NULL),
655bfd7a	250	__ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
bb7ca747	251	__ATTR(type, 0444, backlight_show_type, NULL),
655bfd7a	252	__ATTR_NULL,
1da177e4 LT	253	};
1da177e4 LT	254
325253a6 MG	255	/**
	256	* backlight_force_update - tell the backlight subsystem that hardware state
	257	* has changed
	258	* @bd: the backlight device to update
	259	*
	260	* Updates the internal state of the backlight in response to a hardware event,
	261	* and generate a uevent to notify userspace
	262	*/
	263	void backlight_force_update(struct backlight_device *bd,
	264	enum backlight_update_reason reason)
	265	{
	266	mutex_lock(&bd->ops_lock);
	267	if (bd->ops && bd->ops->get_brightness)
	268	bd->props.brightness = bd->ops->get_brightness(bd);
	269	mutex_unlock(&bd->ops_lock);
	270	backlight_generate_event(bd, reason);
	271	}
	272	EXPORT_SYMBOL(backlight_force_update);
	273
1da177e4 LT	274	/**
	275	* backlight_device_register - create and register a new object of
	276	* backlight_device class.
	277	* @name: the name of the new object(must be the same as the name of the
	278	* respective framebuffer device).
f6ec2d96	279	* @parent: a pointer to the parent device
655bfd7a RP	280	* @devdata: an optional pointer to be stored for private driver use. The
655bfd7a RP	281	* methods may retrieve it by using bl_get_data(bd).
599a52d1	282	* @ops: the backlight operations structure.
1da177e4	283	*
655bfd7a	284	* Creates and registers new backlight device. Returns either an
1da177e4 LT	285	* ERR_PTR() or a pointer to the newly allocated device.
1da177e4 LT	286	*/
519ab5f2	287	struct backlight_device backlight_device_register(const char name,
a19a6ee6 MG	288	struct device parent, void devdata, const struct backlight_ops *ops,
a19a6ee6 MG	289	const struct backlight_properties *props)
1da177e4	290	{
1da177e4	291	struct backlight_device *new_bd;
655bfd7a	292	int rc;
1da177e4	293
655bfd7a	294	pr_debug("backlight_device_register: name=%s\n", name);
1da177e4	295
599a52d1	296	new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL);
90968e8e	297	if (!new_bd)
10ad1b73	298	return ERR_PTR(-ENOMEM);
1da177e4	299
28ee086d	300	mutex_init(&new_bd->update_lock);
599a52d1	301	mutex_init(&new_bd->ops_lock);
1da177e4	302
655bfd7a RP	303	new_bd->dev.class = backlight_class;
	304	new_bd->dev.parent = parent;
	305	new_bd->dev.release = bl_device_release;
64dba9a9	306	dev_set_name(&new_bd->dev, name);
655bfd7a RP	307	dev_set_drvdata(&new_bd->dev, devdata);
655bfd7a RP	308
a19a6ee6	309	/* Set default properties */
bb7ca747	310	if (props) {
a19a6ee6 MG	311	memcpy(&new_bd->props, props,
a19a6ee6 MG	312	sizeof(struct backlight_properties));
bb7ca747 MG	313	if (props->type <= 0 \|\| props->type >= BACKLIGHT_TYPE_MAX) {
	314	WARN(1, "%s: invalid backlight type", name);
	315	new_bd->props.type = BACKLIGHT_RAW;
	316	}
	317	} else {
	318	new_bd->props.type = BACKLIGHT_RAW;
	319	}
a19a6ee6	320
655bfd7a	321	rc = device_register(&new_bd->dev);
90968e8e	322	if (rc) {
2fd5a154	323	kfree(new_bd);
1da177e4 LT	324	return ERR_PTR(rc);
	325	}
	326
3d5eeadd	327	rc = backlight_register_fb(new_bd);
2fd5a154	328	if (rc) {
655bfd7a	329	device_unregister(&new_bd->dev);
2fd5a154 DT	330	return ERR_PTR(rc);
	331	}
	332
655bfd7a	333	new_bd->ops = ops;
1da177e4	334
321709c5 RP	335	#ifdef CONFIG_PMAC_BACKLIGHT
	336	mutex_lock(&pmac_backlight_mutex);
	337	if (!pmac_backlight)
	338	pmac_backlight = new_bd;
	339	mutex_unlock(&pmac_backlight_mutex);
	340	#endif
	341
1da177e4 LT	342	return new_bd;
	343	}
	344	EXPORT_SYMBOL(backlight_device_register);
	345
	346	/**
	347	* backlight_device_unregister - unregisters a backlight device object.
	348	* @bd: the backlight device object to be unregistered and freed.
	349	*
	350	* Unregisters a previously registered via backlight_device_register object.
	351	*/
	352	void backlight_device_unregister(struct backlight_device *bd)
	353	{
1da177e4 LT	354	if (!bd)
	355	return;
	356
321709c5 RP	357	#ifdef CONFIG_PMAC_BACKLIGHT
	358	mutex_lock(&pmac_backlight_mutex);
	359	if (pmac_backlight == bd)
	360	pmac_backlight = NULL;
	361	mutex_unlock(&pmac_backlight_mutex);
	362	#endif
599a52d1 RP	363	mutex_lock(&bd->ops_lock);
	364	bd->ops = NULL;
	365	mutex_unlock(&bd->ops_lock);
1da177e4	366
3d5eeadd	367	backlight_unregister_fb(bd);
655bfd7a	368	device_unregister(&bd->dev);
1da177e4 LT	369	}
	370	EXPORT_SYMBOL(backlight_device_unregister);
	371
	372	static void __exit backlight_class_exit(void)
	373	{
655bfd7a	374	class_destroy(backlight_class);
1da177e4 LT	375	}
	376
	377	static int __init backlight_class_init(void)
	378	{
655bfd7a RP	379	backlight_class = class_create(THIS_MODULE, "backlight");
	380	if (IS_ERR(backlight_class)) {
	381	printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
	382	PTR_ERR(backlight_class));
	383	return PTR_ERR(backlight_class);
	384	}
	385
	386	backlight_class->dev_attrs = bl_device_attributes;
c835ee7f RP	387	backlight_class->suspend = backlight_suspend;
c835ee7f RP	388	backlight_class->resume = backlight_resume;
655bfd7a	389	return 0;
1da177e4 LT	390	}
	391
	392	/*
	393	* if this is compiled into the kernel, we need to ensure that the
	394	* class is registered before users of the class try to register lcd's
	395	*/
	396	postcore_initcall(backlight_class_init);
	397	module_exit(backlight_class_exit);
	398
	399	MODULE_LICENSE("GPL");
	400	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	401	MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");