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

/*
 * LCD 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/lcd.h>
#include <linux/notifier.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/fb.h>
#include <linux/slab.h>

#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
			   defined(CONFIG_LCD_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 lcd power as well ...
 */
static int fb_notifier_callback(struct notifier_block *self,
				 unsigned long event, void *data)
{
	struct lcd_device *ld;
	struct fb_event *evdata = data;

	/* If we aren't interested in this event, skip it immediately ... */
	switch (event) {
	case FB_EVENT_BLANK:
	case FB_EVENT_MODE_CHANGE:
	case FB_EVENT_MODE_CHANGE_ALL:
	case FB_EARLY_EVENT_BLANK:
	case FB_R_EARLY_EVENT_BLANK:
		break;
	default:
		return 0;
	}

	ld = container_of(self, struct lcd_device, fb_notif);
	if (!ld->ops)
		return 0;

	mutex_lock(&ld->ops_lock);
	if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) {
		if (event == FB_EVENT_BLANK) {
			if (ld->ops->set_power)
				ld->ops->set_power(ld, *(int *)evdata->data);
		} else if (event == FB_EARLY_EVENT_BLANK) {
			if (ld->ops->early_set_power)
				ld->ops->early_set_power(ld,
						*(int *)evdata->data);
		} else if (event == FB_R_EARLY_EVENT_BLANK) {
			if (ld->ops->r_early_set_power)
				ld->ops->r_early_set_power(ld,
						*(int *)evdata->data);
		} else {
			if (ld->ops->set_mode)
				ld->ops->set_mode(ld, evdata->data);
		}
	}
	mutex_unlock(&ld->ops_lock);
	return 0;
}

static int lcd_register_fb(struct lcd_device *ld)
{
	memset(&ld->fb_notif, 0, sizeof(ld->fb_notif));
	ld->fb_notif.notifier_call = fb_notifier_callback;
	return fb_register_client(&ld->fb_notif);
}

static void lcd_unregister_fb(struct lcd_device *ld)
{
	fb_unregister_client(&ld->fb_notif);
}
#else
static int lcd_register_fb(struct lcd_device *ld)
{
	return 0;
}

static inline void lcd_unregister_fb(struct lcd_device *ld)
{
}
#endif /* CONFIG_FB */

static ssize_t lcd_power_show(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	int rc;
	struct lcd_device *ld = to_lcd_device(dev);

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->get_power)
		rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
	else
		rc = -ENXIO;
	mutex_unlock(&ld->ops_lock);

	return rc;
}

static ssize_t lcd_power_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	int rc;
	struct lcd_device *ld = to_lcd_device(dev);
	unsigned long power;

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

	rc = -ENXIO;

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->set_power) {
		pr_debug("set power to %lu\n", power);
		ld->ops->set_power(ld, power);
		rc = count;
	}
	mutex_unlock(&ld->ops_lock);

	return rc;
}
static DEVICE_ATTR_RW(lcd_power);

static ssize_t contrast_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	int rc = -ENXIO;
	struct lcd_device *ld = to_lcd_device(dev);

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

	return rc;
}

static ssize_t contrast_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	int rc;
	struct lcd_device *ld = to_lcd_device(dev);
	unsigned long contrast;

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

	rc = -ENXIO;

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->set_contrast) {
		pr_debug("set contrast to %lu\n", contrast);
		ld->ops->set_contrast(ld, contrast);
		rc = count;
	}
	mutex_unlock(&ld->ops_lock);

	return rc;
}
static DEVICE_ATTR_RW(contrast);

static ssize_t max_contrast_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct lcd_device *ld = to_lcd_device(dev);

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

static struct class *lcd_class;

static void lcd_device_release(struct device *dev)
{
	struct lcd_device *ld = to_lcd_device(dev);
	kfree(ld);
}

static struct attribute *lcd_device_attrs[] = {
	&dev_attr_lcd_power.attr,
	&dev_attr_contrast.attr,
	&dev_attr_max_contrast.attr,
	NULL,
};
ATTRIBUTE_GROUPS(lcd_device);

/**
 * lcd_device_register - register a new object of lcd_device class.
 * @name: the name of the new object(must be the same as the name of the
 *   respective framebuffer device).
 * @devdata: an optional pointer to be stored in the device. The
 *   methods may retrieve it by using lcd_get_data(ld).
 * @ops: the lcd operations structure.
 *
 * Creates and registers a new lcd device. Returns either an ERR_PTR()
 * or a pointer to the newly allocated device.
 */
struct lcd_device *lcd_device_register(const char *name, struct device *parent,
		void *devdata, struct lcd_ops *ops)
{
	struct lcd_device *new_ld;
	int rc;

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

	new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
	if (!new_ld)
		return ERR_PTR(-ENOMEM);

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

	new_ld->dev.class = lcd_class;
	new_ld->dev.parent = parent;
	new_ld->dev.release = lcd_device_release;
	dev_set_name(&new_ld->dev, "%s", name);
	dev_set_drvdata(&new_ld->dev, devdata);

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

	rc = lcd_register_fb(new_ld);
	if (rc) {
		device_unregister(&new_ld->dev);
		return ERR_PTR(rc);
	}

	new_ld->ops = ops;

	return new_ld;
}
EXPORT_SYMBOL(lcd_device_register);

/**
 * lcd_device_unregister - unregisters a object of lcd_device class.
 * @ld: the lcd device object to be unregistered and freed.
 *
 * Unregisters a previously registered via lcd_device_register object.
 */
void lcd_device_unregister(struct lcd_device *ld)
{
	if (!ld)
		return;

	mutex_lock(&ld->ops_lock);
	ld->ops = NULL;
	mutex_unlock(&ld->ops_lock);
	lcd_unregister_fb(ld);

	device_unregister(&ld->dev);
}
EXPORT_SYMBOL(lcd_device_unregister);

static void devm_lcd_device_release(struct device *dev, void *res)
{
	struct lcd_device *lcd = *(struct lcd_device **)res;

	lcd_device_unregister(lcd);
}

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

	return *r == data;
}

/**
 * devm_lcd_device_register - resource managed lcd_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 lcd operations structure
 *
 * @return a struct lcd on success, or an ERR_PTR on error
 *
 * Managed lcd_device_register(). The lcd_device returned from this function
 * are automatically freed on driver detach. See lcd_device_register()
 * for more information.
 */
struct lcd_device *devm_lcd_device_register(struct device *dev,
		const char *name, struct device *parent,
		void *devdata, struct lcd_ops *ops)
{
	struct lcd_device **ptr, *lcd;

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

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

	return lcd;
}
EXPORT_SYMBOL(devm_lcd_device_register);

/**
 * devm_lcd_device_unregister - resource managed lcd_device_unregister()
 * @dev: the device to unregister
 * @ld: the lcd device to unregister
 *
 * Deallocated a lcd allocated with devm_lcd_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_lcd_device_unregister(struct device *dev, struct lcd_device *ld)
{
	int rc;

	rc = devres_release(dev, devm_lcd_device_release,
				devm_lcd_device_match, ld);
	WARN_ON(rc);
}
EXPORT_SYMBOL(devm_lcd_device_unregister);


static void __exit lcd_class_exit(void)
{
	class_destroy(lcd_class);
}

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

	lcd_class->dev_groups = lcd_device_groups;
	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(lcd_class_init);
module_exit(lcd_class_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* LCD 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/lcd.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
3d5eeadd JS	20	#if defined(CONFIG_FB) \|\| (defined(CONFIG_FB_MODULE) && \
	21	defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
	22	/* This callback gets called when something important happens inside a
	23	* framebuffer driver. We're looking if that important event is blanking,
	24	* and if it is, we're switching lcd power as well ...
	25	*/
	26	static int fb_notifier_callback(struct notifier_block *self,
	27	unsigned long event, void *data)
	28	{
	29	struct lcd_device *ld;
	30	struct fb_event *evdata = data;
	31
	32	/* If we aren't interested in this event, skip it immediately ... */
faa312da EM	33	switch (event) {
	34	case FB_EVENT_BLANK:
	35	case FB_EVENT_MODE_CHANGE:
	36	case FB_EVENT_MODE_CHANGE_ALL:
d54ad83f ID	37	case FB_EARLY_EVENT_BLANK:
d54ad83f ID	38	case FB_R_EARLY_EVENT_BLANK:
faa312da EM	39	break;
faa312da EM	40	default:
3d5eeadd	41	return 0;
faa312da	42	}
3d5eeadd JS	43
3d5eeadd JS	44	ld = container_of(self, struct lcd_device, fb_notif);
faa312da EM	45	if (!ld->ops)
	46	return 0;
	47
599a52d1	48	mutex_lock(&ld->ops_lock);
faa312da	49	if (!ld->ops->check_fb \|\| ld->ops->check_fb(ld, evdata->info)) {
b3b4dc88 BD	50	if (event == FB_EVENT_BLANK) {
	51	if (ld->ops->set_power)
	52	ld->ops->set_power(ld, (int )evdata->data);
d54ad83f ID	53	} else if (event == FB_EARLY_EVENT_BLANK) {
	54	if (ld->ops->early_set_power)
	55	ld->ops->early_set_power(ld,
	56	(int )evdata->data);
	57	} else if (event == FB_R_EARLY_EVENT_BLANK) {
	58	if (ld->ops->r_early_set_power)
	59	ld->ops->r_early_set_power(ld,
	60	(int )evdata->data);
b3b4dc88 BD	61	} else {
	62	if (ld->ops->set_mode)
	63	ld->ops->set_mode(ld, evdata->data);
	64	}
faa312da	65	}
599a52d1	66	mutex_unlock(&ld->ops_lock);
3d5eeadd JS	67	return 0;
	68	}
	69
	70	static int lcd_register_fb(struct lcd_device *ld)
	71	{
1e0fa6bd	72	memset(&ld->fb_notif, 0, sizeof(ld->fb_notif));
3d5eeadd JS	73	ld->fb_notif.notifier_call = fb_notifier_callback;
	74	return fb_register_client(&ld->fb_notif);
	75	}
	76
	77	static void lcd_unregister_fb(struct lcd_device *ld)
	78	{
	79	fb_unregister_client(&ld->fb_notif);
	80	}
	81	#else
	82	static int lcd_register_fb(struct lcd_device *ld)
	83	{
	84	return 0;
	85	}
	86
	87	static inline void lcd_unregister_fb(struct lcd_device *ld)
	88	{
	89	}
	90	#endif /* CONFIG_FB */
	91
d79fd03f	92	static ssize_t lcd_power_show(struct device dev, struct device_attribute attr,
655bfd7a	93	char *buf)
1da177e4 LT	94	{
1da177e4 LT	95	int rc;
655bfd7a	96	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	97
599a52d1 RP	98	mutex_lock(&ld->ops_lock);
	99	if (ld->ops && ld->ops->get_power)
	100	rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
1da177e4 LT	101	else
1da177e4 LT	102	rc = -ENXIO;
599a52d1	103	mutex_unlock(&ld->ops_lock);
1da177e4 LT	104
	105	return rc;
	106	}
	107
d79fd03f	108	static ssize_t lcd_power_store(struct device *dev,
655bfd7a	109	struct device_attribute attr, const char buf, size_t count)
1da177e4	110	{
424e06e3	111	int rc;
655bfd7a	112	struct lcd_device *ld = to_lcd_device(dev);
66655760	113	unsigned long power;
1da177e4	114
66655760 JH	115	rc = kstrtoul(buf, 0, &power);
	116	if (rc)
	117	return rc;
1da177e4	118
424e06e3 JH	119	rc = -ENXIO;
424e06e3 JH	120
599a52d1 RP	121	mutex_lock(&ld->ops_lock);
599a52d1 RP	122	if (ld->ops && ld->ops->set_power) {
35f96162	123	pr_debug("set power to %lu\n", power);
599a52d1	124	ld->ops->set_power(ld, power);
1da177e4	125	rc = count;
68673afd	126	}
599a52d1	127	mutex_unlock(&ld->ops_lock);
1da177e4 LT	128
	129	return rc;
	130	}
d79fd03f	131	static DEVICE_ATTR_RW(lcd_power);
1da177e4	132
d79fd03f	133	static ssize_t contrast_show(struct device *dev,
655bfd7a	134	struct device_attribute attr, char buf)
1da177e4	135	{
68673afd	136	int rc = -ENXIO;
655bfd7a	137	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	138
599a52d1 RP	139	mutex_lock(&ld->ops_lock);
	140	if (ld->ops && ld->ops->get_contrast)
	141	rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
	142	mutex_unlock(&ld->ops_lock);
1da177e4 LT	143
	144	return rc;
	145	}
	146
d79fd03f	147	static ssize_t contrast_store(struct device *dev,
655bfd7a	148	struct device_attribute attr, const char buf, size_t count)
1da177e4	149	{
424e06e3	150	int rc;
655bfd7a	151	struct lcd_device *ld = to_lcd_device(dev);
66655760	152	unsigned long contrast;
1da177e4	153
66655760 JH	154	rc = kstrtoul(buf, 0, &contrast);
	155	if (rc)
	156	return rc;
1da177e4	157
424e06e3 JH	158	rc = -ENXIO;
424e06e3 JH	159
599a52d1 RP	160	mutex_lock(&ld->ops_lock);
599a52d1 RP	161	if (ld->ops && ld->ops->set_contrast) {
35f96162	162	pr_debug("set contrast to %lu\n", contrast);
599a52d1	163	ld->ops->set_contrast(ld, contrast);
1da177e4	164	rc = count;
68673afd	165	}
599a52d1	166	mutex_unlock(&ld->ops_lock);
1da177e4 LT	167
	168	return rc;
	169	}
d79fd03f	170	static DEVICE_ATTR_RW(contrast);
1da177e4	171
d79fd03f	172	static ssize_t max_contrast_show(struct device *dev,
655bfd7a	173	struct device_attribute attr, char buf)
1da177e4	174	{
655bfd7a	175	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	176
599a52d1	177	return sprintf(buf, "%d\n", ld->props.max_contrast);
1da177e4	178	}
d79fd03f	179	static DEVICE_ATTR_RO(max_contrast);
1da177e4	180
0ad90efd	181	static struct class *lcd_class;
655bfd7a RP	182
655bfd7a RP	183	static void lcd_device_release(struct device *dev)
1da177e4 LT	184	{
	185	struct lcd_device *ld = to_lcd_device(dev);
	186	kfree(ld);
	187	}
	188
d79fd03f GKH	189	static struct attribute *lcd_device_attrs[] = {
	190	&dev_attr_lcd_power.attr,
	191	&dev_attr_contrast.attr,
	192	&dev_attr_max_contrast.attr,
	193	NULL,
1da177e4	194	};
d79fd03f	195	ATTRIBUTE_GROUPS(lcd_device);
1da177e4	196
1da177e4 LT	197	/**
	198	* lcd_device_register - register a new object of lcd_device class.
	199	* @name: the name of the new object(must be the same as the name of the
	200	* respective framebuffer device).
655bfd7a RP	201	* @devdata: an optional pointer to be stored in the device. The
655bfd7a RP	202	* methods may retrieve it by using lcd_get_data(ld).
599a52d1	203	* @ops: the lcd operations structure.
1da177e4	204	*
655bfd7a	205	* Creates and registers a new lcd device. Returns either an ERR_PTR()
1da177e4 LT	206	* or a pointer to the newly allocated device.
1da177e4 LT	207	*/
655bfd7a RP	208	struct lcd_device lcd_device_register(const char name, struct device *parent,
655bfd7a RP	209	void devdata, struct lcd_ops ops)
1da177e4	210	{
1da177e4	211	struct lcd_device *new_ld;
655bfd7a	212	int rc;
1da177e4 LT	213
	214	pr_debug("lcd_device_register: name=%s\n", name);
	215
599a52d1	216	new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
90968e8e	217	if (!new_ld)
10ad1b73	218	return ERR_PTR(-ENOMEM);
1da177e4	219
599a52d1	220	mutex_init(&new_ld->ops_lock);
28ee086d	221	mutex_init(&new_ld->update_lock);
1da177e4	222
655bfd7a RP	223	new_ld->dev.class = lcd_class;
	224	new_ld->dev.parent = parent;
	225	new_ld->dev.release = lcd_device_release;
02aa2a37	226	dev_set_name(&new_ld->dev, "%s", name);
655bfd7a RP	227	dev_set_drvdata(&new_ld->dev, devdata);
	228
	229	rc = device_register(&new_ld->dev);
90968e8e	230	if (rc) {
2fd5a154	231	kfree(new_ld);
1da177e4 LT	232	return ERR_PTR(rc);
	233	}
	234
3d5eeadd	235	rc = lcd_register_fb(new_ld);
2fd5a154	236	if (rc) {
655bfd7a	237	device_unregister(&new_ld->dev);
2fd5a154 DT	238	return ERR_PTR(rc);
2fd5a154 DT	239	}
1da177e4	240
655bfd7a	241	new_ld->ops = ops;
1da177e4 LT	242
	243	return new_ld;
	244	}
	245	EXPORT_SYMBOL(lcd_device_register);
	246
	247	/**
	248	* lcd_device_unregister - unregisters a object of lcd_device class.
	249	* @ld: the lcd device object to be unregistered and freed.
	250	*
	251	* Unregisters a previously registered via lcd_device_register object.
	252	*/
	253	void lcd_device_unregister(struct lcd_device *ld)
	254	{
1da177e4 LT	255	if (!ld)
	256	return;
	257
599a52d1 RP	258	mutex_lock(&ld->ops_lock);
	259	ld->ops = NULL;
	260	mutex_unlock(&ld->ops_lock);
3d5eeadd	261	lcd_unregister_fb(ld);
655bfd7a RP	262
655bfd7a RP	263	device_unregister(&ld->dev);
1da177e4 LT	264	}
	265	EXPORT_SYMBOL(lcd_device_unregister);
	266
1d0c48e6 JH	267	static void devm_lcd_device_release(struct device dev, void res)
	268	{
	269	struct lcd_device lcd = (struct lcd_device **)res;
	270
	271	lcd_device_unregister(lcd);
	272	}
	273
	274	static int devm_lcd_device_match(struct device dev, void res, void *data)
	275	{
	276	struct lcd_device **r = res;
	277
	278	return *r == data;
	279	}
	280
	281	/**
	282	* devm_lcd_device_register - resource managed lcd_device_register()
	283	* @dev: the device to register
	284	* @name: the name of the device
	285	* @parent: a pointer to the parent device
	286	* @devdata: an optional pointer to be stored for private driver use
	287	* @ops: the lcd operations structure
	288	*
	289	* @return a struct lcd on success, or an ERR_PTR on error
	290	*
	291	* Managed lcd_device_register(). The lcd_device returned from this function
	292	* are automatically freed on driver detach. See lcd_device_register()
	293	* for more information.
	294	*/
	295	struct lcd_device devm_lcd_device_register(struct device dev,
	296	const char name, struct device parent,
	297	void devdata, struct lcd_ops ops)
	298	{
	299	struct lcd_device *ptr, lcd;
	300
	301	ptr = devres_alloc(devm_lcd_device_release, sizeof(*ptr), GFP_KERNEL);
	302	if (!ptr)
	303	return ERR_PTR(-ENOMEM);
	304
	305	lcd = lcd_device_register(name, parent, devdata, ops);
	306	if (!IS_ERR(lcd)) {
	307	*ptr = lcd;
	308	devres_add(dev, ptr);
	309	} else {
	310	devres_free(ptr);
	311	}
	312
	313	return lcd;
	314	}
	315	EXPORT_SYMBOL(devm_lcd_device_register);
	316
	317	/**
	318	* devm_lcd_device_unregister - resource managed lcd_device_unregister()
	319	* @dev: the device to unregister
	320	* @ld: the lcd device to unregister
	321	*
	322	* Deallocated a lcd allocated with devm_lcd_device_register(). Normally
	323	* this function will not need to be called and the resource management
	324	* code will ensure that the resource is freed.
	325	*/
	326	void devm_lcd_device_unregister(struct device dev, struct lcd_device ld)
	327	{
	328	int rc;
	329
	330	rc = devres_release(dev, devm_lcd_device_release,
331	devm_lcd_device_match, ld);
332	WARN_ON(rc);
333	}
334	EXPORT_SYMBOL(devm_lcd_device_unregister);
335
336
1da177e4 LT	337	static void __exit lcd_class_exit(void)
1da177e4 LT	338	{
655bfd7a	339	class_destroy(lcd_class);
1da177e4 LT	340	}
	341
	342	static int __init lcd_class_init(void)
	343	{
655bfd7a RP	344	lcd_class = class_create(THIS_MODULE, "lcd");
655bfd7a RP	345	if (IS_ERR(lcd_class)) {
35f96162 JH	346	pr_warn("Unable to create backlight class; errno = %ld\n",
35f96162 JH	347	PTR_ERR(lcd_class));
655bfd7a RP	348	return PTR_ERR(lcd_class);
	349	}
	350
d79fd03f	351	lcd_class->dev_groups = lcd_device_groups;
655bfd7a	352	return 0;
1da177e4 LT	353	}
	354
	355	/*
	356	* if this is compiled into the kernel, we need to ensure that the
	357	* class is registered before users of the class try to register lcd's
	358	*/
	359	postcore_initcall(lcd_class_init);
	360	module_exit(lcd_class_exit);
	361
	362	MODULE_LICENSE("GPL");
	363	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	364	MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");