[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>

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

#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(evdata->info)) {
			bd->props.fb_blank = *(int *)evdata->data;
			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 ssize_t backlight_show_power(struct class_device *cdev, char *buf)
{
	struct backlight_device *bd = to_backlight_device(cdev);

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

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->ops_lock);
	if (bd->ops) {
		pr_debug("backlight: set power to %d\n", 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 class_device *cdev, char *buf)
{
	struct backlight_device *bd = to_backlight_device(cdev);

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

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->ops_lock);
	if (bd->ops) {
		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->ops_lock);

	return rc;
}

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

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

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->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 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 }, \
	.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).
 * @ops: the backlight operations 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_ops *ops)
{
	int i, rc;
	struct backlight_device *new_bd;

	pr_debug("backlight_device_alloc: 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->ops = ops;
	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);
		}
	}

#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)
{
	int i;

	if (!bd)
		return;

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

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

	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->ops_lock);
	bd->ops = NULL;
	mutex_unlock(&bd->ops_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
321709c5 RP	17	#ifdef CONFIG_PMAC_BACKLIGHT
	18	#include <asm/backlight.h>
	19	#endif
3d5eeadd JS	20
	21	#if defined(CONFIG_FB) \|\| (defined(CONFIG_FB_MODULE) && \
	22	defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE))
	23	/* This callback gets called when something important happens inside a
	24	* framebuffer driver. We're looking if that important event is blanking,
	25	* and if it is, we're switching backlight power as well ...
	26	*/
	27	static int fb_notifier_callback(struct notifier_block *self,
	28	unsigned long event, void *data)
	29	{
	30	struct backlight_device *bd;
	31	struct fb_event *evdata = data;
	32
	33	/* If we aren't interested in this event, skip it immediately ... */
994efacd	34	if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK)
3d5eeadd JS	35	return 0;
	36
	37	bd = container_of(self, struct backlight_device, fb_notif);
599a52d1 RP	38	mutex_lock(&bd->ops_lock);
	39	if (bd->ops)
	40	if (!bd->ops->check_fb \|\|
	41	bd->ops->check_fb(evdata->info)) {
	42	bd->props.fb_blank = (int )evdata->data;
28ee086d	43	backlight_update_status(bd);
3d5eeadd	44	}
599a52d1	45	mutex_unlock(&bd->ops_lock);
3d5eeadd JS	46	return 0;
	47	}
	48
	49	static int backlight_register_fb(struct backlight_device *bd)
	50	{
	51	memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
	52	bd->fb_notif.notifier_call = fb_notifier_callback;
	53
	54	return fb_register_client(&bd->fb_notif);
	55	}
	56
	57	static void backlight_unregister_fb(struct backlight_device *bd)
	58	{
	59	fb_unregister_client(&bd->fb_notif);
	60	}
	61	#else
	62	static inline int backlight_register_fb(struct backlight_device *bd)
	63	{
	64	return 0;
	65	}
	66
	67	static inline void backlight_unregister_fb(struct backlight_device *bd)
	68	{
	69	}
	70	#endif /* CONFIG_FB */
	71
1da177e4 LT	72	static ssize_t backlight_show_power(struct class_device cdev, char buf)
1da177e4 LT	73	{
1da177e4 LT	74	struct backlight_device *bd = to_backlight_device(cdev);
1da177e4 LT	75
599a52d1	76	return sprintf(buf, "%d\n", bd->props.power);
1da177e4 LT	77	}
	78
	79	static ssize_t backlight_store_power(struct class_device cdev, const char buf, size_t count)
	80	{
68673afd	81	int rc = -ENXIO;
1da177e4 LT	82	char *endp;
1da177e4 LT	83	struct backlight_device *bd = to_backlight_device(cdev);
68673afd RP	84	int power = simple_strtoul(buf, &endp, 0);
68673afd RP	85	size_t size = endp - buf;
1da177e4	86
68673afd RP	87	if (endp && isspace(endp))
	88	size++;
	89	if (size != count)
1da177e4 LT	90	return -EINVAL;
1da177e4 LT	91
599a52d1 RP	92	mutex_lock(&bd->ops_lock);
599a52d1 RP	93	if (bd->ops) {
1da177e4	94	pr_debug("backlight: set power to %d\n", power);
599a52d1	95	bd->props.power = power;
28ee086d	96	backlight_update_status(bd);
1da177e4	97	rc = count;
6ca01765	98	}
599a52d1	99	mutex_unlock(&bd->ops_lock);
1da177e4 LT	100
	101	return rc;
	102	}
	103
	104	static ssize_t backlight_show_brightness(struct class_device cdev, char buf)
	105	{
1da177e4 LT	106	struct backlight_device *bd = to_backlight_device(cdev);
1da177e4 LT	107
599a52d1	108	return sprintf(buf, "%d\n", bd->props.brightness);
1da177e4 LT	109	}
	110
	111	static ssize_t backlight_store_brightness(struct class_device cdev, const char buf, size_t count)
	112	{
68673afd	113	int rc = -ENXIO;
1da177e4 LT	114	char *endp;
1da177e4 LT	115	struct backlight_device *bd = to_backlight_device(cdev);
68673afd RP	116	int brightness = simple_strtoul(buf, &endp, 0);
68673afd RP	117	size_t size = endp - buf;
1da177e4	118
68673afd RP	119	if (endp && isspace(endp))
	120	size++;
	121	if (size != count)
1da177e4 LT	122	return -EINVAL;
1da177e4 LT	123
599a52d1 RP	124	mutex_lock(&bd->ops_lock);
	125	if (bd->ops) {
	126	if (brightness > bd->props.max_brightness)
6ca01765 RP	127	rc = -EINVAL;
	128	else {
	129	pr_debug("backlight: set brightness to %d\n",
	130	brightness);
599a52d1	131	bd->props.brightness = brightness;
28ee086d	132	backlight_update_status(bd);
6ca01765 RP	133	rc = count;
	134	}
	135	}
599a52d1	136	mutex_unlock(&bd->ops_lock);
1da177e4 LT	137
	138	return rc;
	139	}
	140
	141	static ssize_t backlight_show_max_brightness(struct class_device cdev, char buf)
	142	{
1da177e4 LT	143	struct backlight_device *bd = to_backlight_device(cdev);
1da177e4 LT	144
599a52d1	145	return sprintf(buf, "%d\n", bd->props.max_brightness);
6ca01765 RP	146	}
	147
	148	static ssize_t backlight_show_actual_brightness(struct class_device *cdev,
	149	char *buf)
	150	{
	151	int rc = -ENXIO;
	152	struct backlight_device *bd = to_backlight_device(cdev);
	153
599a52d1 RP	154	mutex_lock(&bd->ops_lock);
	155	if (bd->ops && bd->ops->get_brightness)
	156	rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
	157	mutex_unlock(&bd->ops_lock);
1da177e4 LT	158
	159	return rc;
	160	}
	161
	162	static void backlight_class_release(struct class_device *dev)
	163	{
	164	struct backlight_device *bd = to_backlight_device(dev);
	165	kfree(bd);
	166	}
	167
	168	static struct class backlight_class = {
	169	.name = "backlight",
	170	.release = backlight_class_release,
	171	};
	172
	173	#define DECLARE_ATTR(_name,_mode,_show,_store) \
	174	{ \
7b595756	175	.attr = { .name = __stringify(_name), .mode = _mode }, \
1da177e4 LT	176	.show = _show, \
	177	.store = _store, \
	178	}
	179
d95159cf	180	static const struct class_device_attribute bl_class_device_attributes[] = {
1da177e4	181	DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power),
6ca01765 RP	182	DECLARE_ATTR(brightness, 0644, backlight_show_brightness,
	183	backlight_store_brightness),
	184	DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
	185	NULL),
1da177e4 LT	186	DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
	187	};
	188
1da177e4 LT	189	/**
	190	* backlight_device_register - create and register a new object of
	191	* backlight_device class.
	192	* @name: the name of the new object(must be the same as the name of the
	193	* respective framebuffer device).
	194	* @devdata: an optional pointer to be stored in the class_device. The
	195	* methods may retrieve it by using class_get_devdata(&bd->class_dev).
599a52d1	196	* @ops: the backlight operations structure.
1da177e4 LT	197	*
	198	* Creates and registers new backlight class_device. Returns either an
	199	* ERR_PTR() or a pointer to the newly allocated device.
	200	*/
519ab5f2 YL	201	struct backlight_device backlight_device_register(const char name,
	202	struct device *dev,
	203	void *devdata,
599a52d1	204	struct backlight_ops *ops)
1da177e4 LT	205	{
	206	int i, rc;
	207	struct backlight_device *new_bd;
	208
	209	pr_debug("backlight_device_alloc: name=%s\n", name);
	210
599a52d1	211	new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL);
90968e8e	212	if (!new_bd)
10ad1b73	213	return ERR_PTR(-ENOMEM);
1da177e4	214
28ee086d	215	mutex_init(&new_bd->update_lock);
599a52d1 RP	216	mutex_init(&new_bd->ops_lock);
599a52d1 RP	217	new_bd->ops = ops;
1da177e4	218	new_bd->class_dev.class = &backlight_class;
519ab5f2	219	new_bd->class_dev.dev = dev;
1da177e4 LT	220	strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN);
	221	class_set_devdata(&new_bd->class_dev, devdata);
	222
	223	rc = class_device_register(&new_bd->class_dev);
90968e8e	224	if (rc) {
2fd5a154	225	kfree(new_bd);
1da177e4 LT	226	return ERR_PTR(rc);
	227	}
	228
3d5eeadd	229	rc = backlight_register_fb(new_bd);
2fd5a154 DT	230	if (rc) {
	231	class_device_unregister(&new_bd->class_dev);
	232	return ERR_PTR(rc);
	233	}
	234
1da177e4 LT	235
	236	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) {
	237	rc = class_device_create_file(&new_bd->class_dev,
	238	&bl_class_device_attributes[i]);
90968e8e	239	if (rc) {
1da177e4 LT	240	while (--i >= 0)
	241	class_device_remove_file(&new_bd->class_dev,
	242	&bl_class_device_attributes[i]);
	243	class_device_unregister(&new_bd->class_dev);
	244	/* No need to kfree(new_bd) since release() method was called */
	245	return ERR_PTR(rc);
	246	}
	247	}
	248
321709c5 RP	249	#ifdef CONFIG_PMAC_BACKLIGHT
	250	mutex_lock(&pmac_backlight_mutex);
	251	if (!pmac_backlight)
	252	pmac_backlight = new_bd;
	253	mutex_unlock(&pmac_backlight_mutex);
	254	#endif
	255
1da177e4 LT	256	return new_bd;
	257	}
	258	EXPORT_SYMBOL(backlight_device_register);
	259
	260	/**
	261	* backlight_device_unregister - unregisters a backlight device object.
	262	* @bd: the backlight device object to be unregistered and freed.
	263	*
	264	* Unregisters a previously registered via backlight_device_register object.
	265	*/
	266	void backlight_device_unregister(struct backlight_device *bd)
	267	{
	268	int i;
	269
	270	if (!bd)
	271	return;
	272
	273	pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id);
	274
321709c5 RP	275	#ifdef CONFIG_PMAC_BACKLIGHT
	276	mutex_lock(&pmac_backlight_mutex);
	277	if (pmac_backlight == bd)
	278	pmac_backlight = NULL;
	279	mutex_unlock(&pmac_backlight_mutex);
	280	#endif
	281
1da177e4 LT	282	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++)
	283	class_device_remove_file(&bd->class_dev,
	284	&bl_class_device_attributes[i]);
	285
599a52d1 RP	286	mutex_lock(&bd->ops_lock);
	287	bd->ops = NULL;
	288	mutex_unlock(&bd->ops_lock);
1da177e4	289
3d5eeadd	290	backlight_unregister_fb(bd);
1da177e4 LT	291
	292	class_device_unregister(&bd->class_dev);
	293	}
	294	EXPORT_SYMBOL(backlight_device_unregister);
	295
	296	static void __exit backlight_class_exit(void)
	297	{
	298	class_unregister(&backlight_class);
	299	}
	300
	301	static int __init backlight_class_init(void)
	302	{
	303	return class_register(&backlight_class);
	304	}
	305
	306	/*
	307	* if this is compiled into the kernel, we need to ensure that the
	308	* class is registered before users of the class try to register lcd's
	309	*/
	310	postcore_initcall(backlight_class_init);
	311	module_exit(backlight_class_exit);
	312
	313	MODULE_LICENSE("GPL");
	314	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	315	MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");