[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>


#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)
		return 0;

	bd = container_of(self, struct backlight_device, fb_notif);
	down(&bd->sem);
	if (bd->props)
		if (!bd->props->check_fb ||
		    bd->props->check_fb(evdata->info)) {
			bd->props->fb_blank = *(int *)evdata->data;
			if (bd->props && bd->props->update_status)
				bd->props->update_status(bd);
		}
	up(&bd->sem);
	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);

	down(&bd->sem);
	if (bd->props)
		rc = sprintf(buf, "%d\n", bd->props->power);
	up(&bd->sem);

	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;

	down(&bd->sem);
	if (bd->props) {
		pr_debug("backlight: set power to %d\n", power);
		bd->props->power = power;
		if (bd->props->update_status)
			bd->props->update_status(bd);
		rc = count;
	}
	up(&bd->sem);

	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);

	down(&bd->sem);
	if (bd->props)
		rc = sprintf(buf, "%d\n", bd->props->brightness);
	up(&bd->sem);

	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;

	down(&bd->sem);
	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;
			if (bd->props->update_status)
				bd->props->update_status(bd);
			rc = count;
		}
	}
	up(&bd->sem);

	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);

	down(&bd->sem);
	if (bd->props)
		rc = sprintf(buf, "%d\n", bd->props->max_brightness);
	up(&bd->sem);

	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);

	down(&bd->sem);
	if (bd->props && bd->props->get_brightness)
		rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
	up(&bd->sem);

	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);

	init_MUTEX(&new_bd->sem);
	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]);

	down(&bd->sem);
	bd->props = NULL;
	up(&bd->sem);

	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 ... */
	31	if (event != FB_EVENT_BLANK)
	32	return 0;
	33
	34	bd = container_of(self, struct backlight_device, fb_notif);
	35	down(&bd->sem);
	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;
90968e8e	40	if (bd->props && bd->props->update_status)
3d5eeadd JS	41	bd->props->update_status(bd);
	42	}
	43	up(&bd->sem);
	44	return 0;
	45	}
	46
	47	static int backlight_register_fb(struct backlight_device *bd)
	48	{
	49	memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
	50	bd->fb_notif.notifier_call = fb_notifier_callback;
	51
	52	return fb_register_client(&bd->fb_notif);
	53	}
	54
	55	static void backlight_unregister_fb(struct backlight_device *bd)
	56	{
	57	fb_unregister_client(&bd->fb_notif);
	58	}
	59	#else
	60	static inline int backlight_register_fb(struct backlight_device *bd)
	61	{
	62	return 0;
	63	}
	64
	65	static inline void backlight_unregister_fb(struct backlight_device *bd)
	66	{
	67	}
	68	#endif /* CONFIG_FB */
	69
1da177e4 LT	70	static ssize_t backlight_show_power(struct class_device cdev, char buf)
1da177e4 LT	71	{
6ca01765	72	int rc = -ENXIO;
1da177e4 LT	73	struct backlight_device *bd = to_backlight_device(cdev);
	74
	75	down(&bd->sem);
90968e8e	76	if (bd->props)
6ca01765	77	rc = sprintf(buf, "%d\n", bd->props->power);
1da177e4 LT	78	up(&bd->sem);
	79
	80	return rc;
	81	}
	82
	83	static ssize_t backlight_store_power(struct class_device cdev, const char buf, size_t count)
	84	{
68673afd	85	int rc = -ENXIO;
1da177e4 LT	86	char *endp;
1da177e4 LT	87	struct backlight_device *bd = to_backlight_device(cdev);
68673afd RP	88	int power = simple_strtoul(buf, &endp, 0);
68673afd RP	89	size_t size = endp - buf;
1da177e4	90
68673afd RP	91	if (endp && isspace(endp))
	92	size++;
	93	if (size != count)
1da177e4 LT	94	return -EINVAL;
	95
	96	down(&bd->sem);
90968e8e	97	if (bd->props) {
1da177e4	98	pr_debug("backlight: set power to %d\n", power);
6ca01765	99	bd->props->power = power;
90968e8e	100	if (bd->props->update_status)
6ca01765	101	bd->props->update_status(bd);
1da177e4	102	rc = count;
6ca01765	103	}
1da177e4 LT	104	up(&bd->sem);
	105
	106	return rc;
	107	}
	108
	109	static ssize_t backlight_show_brightness(struct class_device cdev, char buf)
	110	{
6ca01765	111	int rc = -ENXIO;
1da177e4 LT	112	struct backlight_device *bd = to_backlight_device(cdev);
	113
	114	down(&bd->sem);
90968e8e	115	if (bd->props)
6ca01765	116	rc = sprintf(buf, "%d\n", bd->props->brightness);
1da177e4 LT	117	up(&bd->sem);
	118
	119	return rc;
	120	}
	121
	122	static ssize_t backlight_store_brightness(struct class_device cdev, const char buf, size_t count)
	123	{
68673afd	124	int rc = -ENXIO;
1da177e4 LT	125	char *endp;
1da177e4 LT	126	struct backlight_device *bd = to_backlight_device(cdev);
68673afd RP	127	int brightness = simple_strtoul(buf, &endp, 0);
68673afd RP	128	size_t size = endp - buf;
1da177e4	129
68673afd RP	130	if (endp && isspace(endp))
	131	size++;
	132	if (size != count)
1da177e4 LT	133	return -EINVAL;
	134
	135	down(&bd->sem);
90968e8e	136	if (bd->props) {
6ca01765 RP	137	if (brightness > bd->props->max_brightness)
	138	rc = -EINVAL;
	139	else {
	140	pr_debug("backlight: set brightness to %d\n",
	141	brightness);
	142	bd->props->brightness = brightness;
90968e8e	143	if (bd->props->update_status)
6ca01765 RP	144	bd->props->update_status(bd);
	145	rc = count;
	146	}
	147	}
1da177e4 LT	148	up(&bd->sem);
	149
	150	return rc;
	151	}
	152
	153	static ssize_t backlight_show_max_brightness(struct class_device cdev, char buf)
	154	{
6ca01765	155	int rc = -ENXIO;
1da177e4 LT	156	struct backlight_device *bd = to_backlight_device(cdev);
	157
	158	down(&bd->sem);
90968e8e	159	if (bd->props)
1da177e4	160	rc = sprintf(buf, "%d\n", bd->props->max_brightness);
6ca01765 RP	161	up(&bd->sem);
	162
	163	return rc;
	164	}
	165
	166	static ssize_t backlight_show_actual_brightness(struct class_device *cdev,
	167	char *buf)
	168	{
	169	int rc = -ENXIO;
	170	struct backlight_device *bd = to_backlight_device(cdev);
	171
	172	down(&bd->sem);
90968e8e	173	if (bd->props && bd->props->get_brightness)
6ca01765	174	rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
1da177e4 LT	175	up(&bd->sem);
	176
	177	return rc;
	178	}
	179
	180	static void backlight_class_release(struct class_device *dev)
	181	{
	182	struct backlight_device *bd = to_backlight_device(dev);
	183	kfree(bd);
	184	}
	185
	186	static struct class backlight_class = {
	187	.name = "backlight",
	188	.release = backlight_class_release,
	189	};
	190
	191	#define DECLARE_ATTR(_name,_mode,_show,_store) \
	192	{ \
	193	.attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \
	194	.show = _show, \
	195	.store = _store, \
	196	}
	197
d95159cf	198	static const struct class_device_attribute bl_class_device_attributes[] = {
1da177e4	199	DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
6ca01765 RP	200	DECLARE_ATTR(brightness, 0644, backlight_show_brightness,
	201	backlight_store_brightness),
	202	DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
	203	NULL),
1da177e4 LT	204	DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
	205	};
	206
1da177e4 LT	207	/**
	208	* backlight_device_register - create and register a new object of
	209	* backlight_device class.
	210	* @name: the name of the new object(must be the same as the name of the
	211	* respective framebuffer device).
	212	* @devdata: an optional pointer to be stored in the class_device. The
	213	* methods may retrieve it by using class_get_devdata(&bd->class_dev).
	214	* @bp: the backlight properties structure.
	215	*
	216	* Creates and registers new backlight class_device. Returns either an
	217	* ERR_PTR() or a pointer to the newly allocated device.
	218	*/
519ab5f2 YL	219	struct backlight_device backlight_device_register(const char name,
	220	struct device *dev,
	221	void *devdata,
	222	struct backlight_properties *bp)
1da177e4 LT	223	{
	224	int i, rc;
	225	struct backlight_device *new_bd;
	226
	227	pr_debug("backlight_device_alloc: name=%s\n", name);
	228
	229	new_bd = kmalloc(sizeof(struct backlight_device), GFP_KERNEL);
90968e8e	230	if (!new_bd)
10ad1b73	231	return ERR_PTR(-ENOMEM);
1da177e4 LT	232
	233	init_MUTEX(&new_bd->sem);
	234	new_bd->props = bp;
	235	memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev));
	236	new_bd->class_dev.class = &backlight_class;
519ab5f2	237	new_bd->class_dev.dev = dev;
1da177e4 LT	238	strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN);
	239	class_set_devdata(&new_bd->class_dev, devdata);
	240
	241	rc = class_device_register(&new_bd->class_dev);
90968e8e	242	if (rc) {
2fd5a154	243	kfree(new_bd);
1da177e4 LT	244	return ERR_PTR(rc);
	245	}
	246
3d5eeadd	247	rc = backlight_register_fb(new_bd);
2fd5a154 DT	248	if (rc) {
	249	class_device_unregister(&new_bd->class_dev);
	250	return ERR_PTR(rc);
	251	}
	252
1da177e4 LT	253
	254	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) {
	255	rc = class_device_create_file(&new_bd->class_dev,
	256	&bl_class_device_attributes[i]);
90968e8e	257	if (rc) {
1da177e4 LT	258	while (--i >= 0)
	259	class_device_remove_file(&new_bd->class_dev,
	260	&bl_class_device_attributes[i]);
	261	class_device_unregister(&new_bd->class_dev);
	262	/* No need to kfree(new_bd) since release() method was called */
	263	return ERR_PTR(rc);
	264	}
	265	}
	266
	267	return new_bd;
	268	}
	269	EXPORT_SYMBOL(backlight_device_register);
	270
	271	/**
	272	* backlight_device_unregister - unregisters a backlight device object.
	273	* @bd: the backlight device object to be unregistered and freed.
	274	*
	275	* Unregisters a previously registered via backlight_device_register object.
	276	*/
	277	void backlight_device_unregister(struct backlight_device *bd)
	278	{
	279	int i;
	280
	281	if (!bd)
	282	return;
	283
	284	pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id);
	285
	286	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++)
	287	class_device_remove_file(&bd->class_dev,
	288	&bl_class_device_attributes[i]);
	289
	290	down(&bd->sem);
	291	bd->props = NULL;
	292	up(&bd->sem);
	293
3d5eeadd	294	backlight_unregister_fb(bd);
1da177e4 LT	295
	296	class_device_unregister(&bd->class_dev);
	297	}
	298	EXPORT_SYMBOL(backlight_device_unregister);
	299
	300	static void __exit backlight_class_exit(void)
	301	{
	302	class_unregister(&backlight_class);
	303	}
	304
	305	static int __init backlight_class_init(void)
	306	{
	307	return class_register(&backlight_class);
	308	}
	309
	310	/*
	311	* if this is compiled into the kernel, we need to ensure that the
	312	* class is registered before users of the class try to register lcd's
	313	*/
	314	postcore_initcall(backlight_class_init);
	315	module_exit(backlight_class_exit);
	316
	317	MODULE_LICENSE("GPL");
	318	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	319	MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");