[linux-2.6-block.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>


#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->props_lock);
	if (bd->props)
		if (!bd->props->check_fb ||
		    bd->props->check_fb(evdata->info)) {
			bd->props->fb_blank = *(int *)evdata->data;
			backlight_update_status(bd);
		}
	mutex_unlock(&bd->props_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 ssize_t backlight_show_power(struct class_device *cdev, char *buf)
{
	int rc = -ENXIO;
	struct backlight_device *bd = to_backlight_device(cdev);

	mutex_lock(&bd->props_lock);
	if (bd->props)
		rc = sprintf(buf, "%d\n", bd->props->power);
	mutex_unlock(&bd->props_lock);

	return rc;
}

static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count)
{
	int rc = -ENXIO;
	char *endp;
	struct backlight_device *bd = to_backlight_device(cdev);
	int power = simple_strtoul(buf, &endp, 0);
	size_t size = endp - buf;

	if (*endp && isspace(*endp))
		size++;
	if (size != count)
		return -EINVAL;

	mutex_lock(&bd->props_lock);
	if (bd->props) {
		pr_debug("backlight: set power to %d\n", power);
		bd->props->power = power;
		backlight_update_status(bd);
		rc = count;
	}
	mutex_unlock(&bd->props_lock);

	return rc;
}

static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf)
{
	int rc = -ENXIO;
	struct backlight_device *bd = to_backlight_device(cdev);

	mutex_lock(&bd->props_lock);
	if (bd->props)
		rc = sprintf(buf, "%d\n", bd->props->brightness);
	mutex_unlock(&bd->props_lock);

	return rc;
}

static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count)
{
	int rc = -ENXIO;
	char *endp;
	struct backlight_device *bd = to_backlight_device(cdev);
	int brightness = simple_strtoul(buf, &endp, 0);
	size_t size = endp - buf;

	if (*endp && isspace(*endp))
		size++;
	if (size != count)
		return -EINVAL;

	mutex_lock(&bd->props_lock);
	if (bd->props) {
		if (brightness > bd->props->max_brightness)
			rc = -EINVAL;
		else {
			pr_debug("backlight: set brightness to %d\n",
				 brightness);
			bd->props->brightness = brightness;
			backlight_update_status(bd);
			rc = count;
		}
	}
	mutex_unlock(&bd->props_lock);

	return rc;
}

static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf)
{
	int rc = -ENXIO;
	struct backlight_device *bd = to_backlight_device(cdev);

	mutex_lock(&bd->props_lock);
	if (bd->props)
		rc = sprintf(buf, "%d\n", bd->props->max_brightness);
	mutex_unlock(&bd->props_lock);

	return rc;
}

static ssize_t backlight_show_actual_brightness(struct class_device *cdev,
						char *buf)
{
	int rc = -ENXIO;
	struct backlight_device *bd = to_backlight_device(cdev);

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

	return rc;
}

static void backlight_class_release(struct class_device *dev)
{
	struct backlight_device *bd = to_backlight_device(dev);
	kfree(bd);
}

static struct class backlight_class = {
	.name = "backlight",
	.release = backlight_class_release,
};

#define DECLARE_ATTR(_name,_mode,_show,_store)			\
{							 	\
	.attr	= { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE },	\
	.show	= _show,					\
	.store	= _store,					\
}

static const struct class_device_attribute bl_class_device_attributes[] = {
	DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
	DECLARE_ATTR(brightness, 0644, backlight_show_brightness,
		     backlight_store_brightness),
	DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
		     NULL),
	DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
};

/**
 * 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).
 * @devdata: an optional pointer to be stored in the class_device. The
 *   methods may retrieve it by using class_get_devdata(&bd->class_dev).
 * @bp: the backlight properties structure.
 *
 * Creates and registers new backlight class_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 *dev,
	void *devdata,
	struct backlight_properties *bp)
{
	int i, rc;
	struct backlight_device *new_bd;

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

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

	mutex_init(&new_bd->update_lock);
	mutex_init(&new_bd->props_lock);
	new_bd->props = bp;
	memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev));
	new_bd->class_dev.class = &backlight_class;
	new_bd->class_dev.dev = dev;
	strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN);
	class_set_devdata(&new_bd->class_dev, devdata);

	rc = class_device_register(&new_bd->class_dev);
	if (rc) {
		kfree(new_bd);
		return ERR_PTR(rc);
	}

	rc = backlight_register_fb(new_bd);
	if (rc) {
		class_device_unregister(&new_bd->class_dev);
		return ERR_PTR(rc);
	}


	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) {
		rc = class_device_create_file(&new_bd->class_dev,
					      &bl_class_device_attributes[i]);
		if (rc) {
			while (--i >= 0)
				class_device_remove_file(&new_bd->class_dev,
							 &bl_class_device_attributes[i]);
			class_device_unregister(&new_bd->class_dev);
			/* No need to kfree(new_bd) since release() method was called */
			return ERR_PTR(rc);
		}
	}

	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)
{
	int i;

	if (!bd)
		return;

	pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id);

	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++)
		class_device_remove_file(&bd->class_dev,
					 &bl_class_device_attributes[i]);

	mutex_lock(&bd->props_lock);
	bd->props = NULL;
	mutex_unlock(&bd->props_lock);

	backlight_unregister_fb(bd);

	class_device_unregister(&bd->class_dev);
}
EXPORT_SYMBOL(backlight_device_unregister);

static void __exit backlight_class_exit(void)
{
	class_unregister(&backlight_class);
}

static int __init backlight_class_init(void)
{
	return class_register(&backlight_class);
}

/*
 * 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>
1da177e4	16
3d5eeadd JS	17
	18	#if defined(CONFIG_FB) \|\| (defined(CONFIG_FB_MODULE) && \
	19	defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
	20	/* This callback gets called when something important happens inside a
	21	* framebuffer driver. We're looking if that important event is blanking,
	22	* and if it is, we're switching backlight power as well ...
	23	*/
	24	static int fb_notifier_callback(struct notifier_block *self,
	25	unsigned long event, void *data)
	26	{
	27	struct backlight_device *bd;
	28	struct fb_event *evdata = data;
	29
	30	/* If we aren't interested in this event, skip it immediately ... */
994efacd	31	if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
3d5eeadd JS	32	return 0;
	33
	34	bd = container_of(self, struct backlight_device, fb_notif);
249040dc	35	mutex_lock(&bd->props_lock);
3d5eeadd JS	36	if (bd->props)
	37	if (!bd->props->check_fb \|\|
	38	bd->props->check_fb(evdata->info)) {
	39	bd->props->fb_blank = (int )evdata->data;
28ee086d	40	backlight_update_status(bd);
3d5eeadd	41	}
249040dc	42	mutex_unlock(&bd->props_lock);
3d5eeadd JS	43	return 0;
	44	}
	45
	46	static int backlight_register_fb(struct backlight_device *bd)
	47	{
	48	memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
	49	bd->fb_notif.notifier_call = fb_notifier_callback;
	50
	51	return fb_register_client(&bd->fb_notif);
	52	}
	53
	54	static void backlight_unregister_fb(struct backlight_device *bd)
	55	{
	56	fb_unregister_client(&bd->fb_notif);
	57	}
	58	#else
	59	static inline int backlight_register_fb(struct backlight_device *bd)
	60	{
	61	return 0;
	62	}
	63
	64	static inline void backlight_unregister_fb(struct backlight_device *bd)
	65	{
	66	}
	67	#endif /* CONFIG_FB */
	68
1da177e4 LT	69	static ssize_t backlight_show_power(struct class_device cdev, char buf)
1da177e4 LT	70	{
6ca01765	71	int rc = -ENXIO;
1da177e4 LT	72	struct backlight_device *bd = to_backlight_device(cdev);
1da177e4 LT	73
249040dc	74	mutex_lock(&bd->props_lock);
90968e8e	75	if (bd->props)
6ca01765	76	rc = sprintf(buf, "%d\n", bd->props->power);
249040dc	77	mutex_unlock(&bd->props_lock);
1da177e4 LT	78
	79	return rc;
	80	}
	81
	82	static ssize_t backlight_store_power(struct class_device cdev, const char buf, size_t count)
	83	{
68673afd	84	int rc = -ENXIO;
1da177e4 LT	85	char *endp;
1da177e4 LT	86	struct backlight_device *bd = to_backlight_device(cdev);
68673afd RP	87	int power = simple_strtoul(buf, &endp, 0);
68673afd RP	88	size_t size = endp - buf;
1da177e4	89
68673afd RP	90	if (endp && isspace(endp))
	91	size++;
	92	if (size != count)
1da177e4 LT	93	return -EINVAL;
1da177e4 LT	94
249040dc	95	mutex_lock(&bd->props_lock);
90968e8e	96	if (bd->props) {
1da177e4	97	pr_debug("backlight: set power to %d\n", power);
6ca01765	98	bd->props->power = power;
28ee086d	99	backlight_update_status(bd);
1da177e4	100	rc = count;
6ca01765	101	}
249040dc	102	mutex_unlock(&bd->props_lock);
1da177e4 LT	103
	104	return rc;
	105	}
	106
	107	static ssize_t backlight_show_brightness(struct class_device cdev, char buf)
	108	{
6ca01765	109	int rc = -ENXIO;
1da177e4 LT	110	struct backlight_device *bd = to_backlight_device(cdev);
1da177e4 LT	111
249040dc	112	mutex_lock(&bd->props_lock);
90968e8e	113	if (bd->props)
6ca01765	114	rc = sprintf(buf, "%d\n", bd->props->brightness);
249040dc	115	mutex_unlock(&bd->props_lock);
1da177e4 LT	116
	117	return rc;
	118	}
	119
	120	static ssize_t backlight_store_brightness(struct class_device cdev, const char buf, size_t count)
	121	{
68673afd	122	int rc = -ENXIO;
1da177e4 LT	123	char *endp;
1da177e4 LT	124	struct backlight_device *bd = to_backlight_device(cdev);
68673afd RP	125	int brightness = simple_strtoul(buf, &endp, 0);
68673afd RP	126	size_t size = endp - buf;
1da177e4	127
68673afd RP	128	if (endp && isspace(endp))
	129	size++;
	130	if (size != count)
1da177e4 LT	131	return -EINVAL;
1da177e4 LT	132
249040dc	133	mutex_lock(&bd->props_lock);
90968e8e	134	if (bd->props) {
6ca01765 RP	135	if (brightness > bd->props->max_brightness)
	136	rc = -EINVAL;
	137	else {
	138	pr_debug("backlight: set brightness to %d\n",
	139	brightness);
	140	bd->props->brightness = brightness;
28ee086d	141	backlight_update_status(bd);
6ca01765 RP	142	rc = count;
	143	}
	144	}
249040dc	145	mutex_unlock(&bd->props_lock);
1da177e4 LT	146
	147	return rc;
	148	}
	149
	150	static ssize_t backlight_show_max_brightness(struct class_device cdev, char buf)
	151	{
6ca01765	152	int rc = -ENXIO;
1da177e4 LT	153	struct backlight_device *bd = to_backlight_device(cdev);
1da177e4 LT	154
249040dc	155	mutex_lock(&bd->props_lock);
90968e8e	156	if (bd->props)
1da177e4	157	rc = sprintf(buf, "%d\n", bd->props->max_brightness);
249040dc	158	mutex_unlock(&bd->props_lock);
6ca01765 RP	159
	160	return rc;
	161	}
	162
	163	static ssize_t backlight_show_actual_brightness(struct class_device *cdev,
	164	char *buf)
	165	{
	166	int rc = -ENXIO;
	167	struct backlight_device *bd = to_backlight_device(cdev);
	168
249040dc	169	mutex_lock(&bd->props_lock);
90968e8e	170	if (bd->props && bd->props->get_brightness)
6ca01765	171	rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
249040dc	172	mutex_unlock(&bd->props_lock);
1da177e4 LT	173
	174	return rc;
	175	}
	176
	177	static void backlight_class_release(struct class_device *dev)
	178	{
	179	struct backlight_device *bd = to_backlight_device(dev);
	180	kfree(bd);
	181	}
	182
	183	static struct class backlight_class = {
	184	.name = "backlight",
	185	.release = backlight_class_release,
	186	};
	187
	188	#define DECLARE_ATTR(_name,_mode,_show,_store) \
	189	{ \
	190	.attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \
	191	.show = _show, \
	192	.store = _store, \
	193	}
	194
d95159cf	195	static const struct class_device_attribute bl_class_device_attributes[] = {
1da177e4	196	DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
6ca01765 RP	197	DECLARE_ATTR(brightness, 0644, backlight_show_brightness,
	198	backlight_store_brightness),
	199	DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
	200	NULL),
1da177e4 LT	201	DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
	202	};
	203
1da177e4 LT	204	/**
	205	* backlight_device_register - create and register a new object of
	206	* backlight_device class.
	207	* @name: the name of the new object(must be the same as the name of the
	208	* respective framebuffer device).
	209	* @devdata: an optional pointer to be stored in the class_device. The
	210	* methods may retrieve it by using class_get_devdata(&bd->class_dev).
	211	* @bp: the backlight properties structure.
	212	*
	213	* Creates and registers new backlight class_device. Returns either an
	214	* ERR_PTR() or a pointer to the newly allocated device.
	215	*/
519ab5f2 YL	216	struct backlight_device backlight_device_register(const char name,
	217	struct device *dev,
	218	void *devdata,
	219	struct backlight_properties *bp)
1da177e4 LT	220	{
	221	int i, rc;
	222	struct backlight_device *new_bd;
	223
	224	pr_debug("backlight_device_alloc: name=%s\n", name);
	225
	226	new_bd = kmalloc(sizeof(struct backlight_device), GFP_KERNEL);
90968e8e	227	if (!new_bd)
10ad1b73	228	return ERR_PTR(-ENOMEM);
1da177e4	229
28ee086d	230	mutex_init(&new_bd->update_lock);
249040dc	231	mutex_init(&new_bd->props_lock);
1da177e4 LT	232	new_bd->props = bp;
	233	memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev));
	234	new_bd->class_dev.class = &backlight_class;
519ab5f2	235	new_bd->class_dev.dev = dev;
1da177e4 LT	236	strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN);
	237	class_set_devdata(&new_bd->class_dev, devdata);
	238
	239	rc = class_device_register(&new_bd->class_dev);
90968e8e	240	if (rc) {
2fd5a154	241	kfree(new_bd);
1da177e4 LT	242	return ERR_PTR(rc);
	243	}
	244
3d5eeadd	245	rc = backlight_register_fb(new_bd);
2fd5a154 DT	246	if (rc) {
	247	class_device_unregister(&new_bd->class_dev);
	248	return ERR_PTR(rc);
	249	}
	250
1da177e4 LT	251
	252	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) {
	253	rc = class_device_create_file(&new_bd->class_dev,
	254	&bl_class_device_attributes[i]);
90968e8e	255	if (rc) {
1da177e4 LT	256	while (--i >= 0)
	257	class_device_remove_file(&new_bd->class_dev,
	258	&bl_class_device_attributes[i]);
	259	class_device_unregister(&new_bd->class_dev);
	260	/* No need to kfree(new_bd) since release() method was called */
	261	return ERR_PTR(rc);
	262	}
	263	}
	264
	265	return new_bd;
	266	}
	267	EXPORT_SYMBOL(backlight_device_register);
	268
	269	/**
	270	* backlight_device_unregister - unregisters a backlight device object.
	271	* @bd: the backlight device object to be unregistered and freed.
	272	*
	273	* Unregisters a previously registered via backlight_device_register object.
	274	*/
	275	void backlight_device_unregister(struct backlight_device *bd)
	276	{
	277	int i;
	278
	279	if (!bd)
	280	return;
	281
	282	pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id);
	283
	284	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++)
	285	class_device_remove_file(&bd->class_dev,
	286	&bl_class_device_attributes[i]);
	287
249040dc	288	mutex_lock(&bd->props_lock);
1da177e4	289	bd->props = NULL;
249040dc	290	mutex_unlock(&bd->props_lock);
1da177e4	291
3d5eeadd	292	backlight_unregister_fb(bd);
1da177e4 LT	293
	294	class_device_unregister(&bd->class_dev);
	295	}
	296	EXPORT_SYMBOL(backlight_device_unregister);
	297
	298	static void __exit backlight_class_exit(void)
	299	{
	300	class_unregister(&backlight_class);
	301	}
	302
	303	static int __init backlight_class_init(void)
	304	{
	305	return class_register(&backlight_class);
	306	}
	307
	308	/*
	309	* if this is compiled into the kernel, we need to ensure that the
	310	* class is registered before users of the class try to register lcd's
	311	*/
	312	postcore_initcall(backlight_class_init);
	313	module_exit(backlight_class_exit);
	314
	315	MODULE_LICENSE("GPL");
	316	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	317	MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");