[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->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);
		}
	}

#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->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
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);
249040dc	38	mutex_lock(&bd->props_lock);
3d5eeadd JS	39	if (bd->props)
	40	if (!bd->props->check_fb \|\|
	41	bd->props->check_fb(evdata->info)) {
	42	bd->props->fb_blank = (int )evdata->data;
28ee086d	43	backlight_update_status(bd);
3d5eeadd	44	}
249040dc	45	mutex_unlock(&bd->props_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	{
6ca01765	74	int rc = -ENXIO;
1da177e4 LT	75	struct backlight_device *bd = to_backlight_device(cdev);
1da177e4 LT	76
249040dc	77	mutex_lock(&bd->props_lock);
90968e8e	78	if (bd->props)
6ca01765	79	rc = sprintf(buf, "%d\n", bd->props->power);
249040dc	80	mutex_unlock(&bd->props_lock);
1da177e4 LT	81
	82	return rc;
	83	}
	84
	85	static ssize_t backlight_store_power(struct class_device cdev, const char buf, size_t count)
	86	{
68673afd	87	int rc = -ENXIO;
1da177e4 LT	88	char *endp;
1da177e4 LT	89	struct backlight_device *bd = to_backlight_device(cdev);
68673afd RP	90	int power = simple_strtoul(buf, &endp, 0);
68673afd RP	91	size_t size = endp - buf;
1da177e4	92
68673afd RP	93	if (endp && isspace(endp))
	94	size++;
	95	if (size != count)
1da177e4 LT	96	return -EINVAL;
1da177e4 LT	97
249040dc	98	mutex_lock(&bd->props_lock);
90968e8e	99	if (bd->props) {
1da177e4	100	pr_debug("backlight: set power to %d\n", power);
6ca01765	101	bd->props->power = power;
28ee086d	102	backlight_update_status(bd);
1da177e4	103	rc = count;
6ca01765	104	}
249040dc	105	mutex_unlock(&bd->props_lock);
1da177e4 LT	106
	107	return rc;
	108	}
	109
	110	static ssize_t backlight_show_brightness(struct class_device cdev, char buf)
	111	{
6ca01765	112	int rc = -ENXIO;
1da177e4 LT	113	struct backlight_device *bd = to_backlight_device(cdev);
1da177e4 LT	114
249040dc	115	mutex_lock(&bd->props_lock);
90968e8e	116	if (bd->props)
6ca01765	117	rc = sprintf(buf, "%d\n", bd->props->brightness);
249040dc	118	mutex_unlock(&bd->props_lock);
1da177e4 LT	119
	120	return rc;
	121	}
	122
	123	static ssize_t backlight_store_brightness(struct class_device cdev, const char buf, size_t count)
	124	{
68673afd	125	int rc = -ENXIO;
1da177e4 LT	126	char *endp;
1da177e4 LT	127	struct backlight_device *bd = to_backlight_device(cdev);
68673afd RP	128	int brightness = simple_strtoul(buf, &endp, 0);
68673afd RP	129	size_t size = endp - buf;
1da177e4	130
68673afd RP	131	if (endp && isspace(endp))
	132	size++;
	133	if (size != count)
1da177e4 LT	134	return -EINVAL;
1da177e4 LT	135
249040dc	136	mutex_lock(&bd->props_lock);
90968e8e	137	if (bd->props) {
6ca01765 RP	138	if (brightness > bd->props->max_brightness)
	139	rc = -EINVAL;
	140	else {
	141	pr_debug("backlight: set brightness to %d\n",
	142	brightness);
	143	bd->props->brightness = brightness;
28ee086d	144	backlight_update_status(bd);
6ca01765 RP	145	rc = count;
	146	}
	147	}
249040dc	148	mutex_unlock(&bd->props_lock);
1da177e4 LT	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);
1da177e4 LT	157
249040dc	158	mutex_lock(&bd->props_lock);
90968e8e	159	if (bd->props)
1da177e4	160	rc = sprintf(buf, "%d\n", bd->props->max_brightness);
249040dc	161	mutex_unlock(&bd->props_lock);
6ca01765 RP	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
249040dc	172	mutex_lock(&bd->props_lock);
90968e8e	173	if (bd->props && bd->props->get_brightness)
6ca01765	174	rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd));
249040dc	175	mutex_unlock(&bd->props_lock);
1da177e4 LT	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	232
28ee086d	233	mutex_init(&new_bd->update_lock);
249040dc	234	mutex_init(&new_bd->props_lock);
1da177e4 LT	235	new_bd->props = bp;
	236	memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev));
	237	new_bd->class_dev.class = &backlight_class;
519ab5f2	238	new_bd->class_dev.dev = dev;
1da177e4 LT	239	strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN);
	240	class_set_devdata(&new_bd->class_dev, devdata);
	241
	242	rc = class_device_register(&new_bd->class_dev);
90968e8e	243	if (rc) {
2fd5a154	244	kfree(new_bd);
1da177e4 LT	245	return ERR_PTR(rc);
	246	}
	247
3d5eeadd	248	rc = backlight_register_fb(new_bd);
2fd5a154 DT	249	if (rc) {
	250	class_device_unregister(&new_bd->class_dev);
	251	return ERR_PTR(rc);
	252	}
	253
1da177e4 LT	254
	255	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) {
	256	rc = class_device_create_file(&new_bd->class_dev,
	257	&bl_class_device_attributes[i]);
90968e8e	258	if (rc) {
1da177e4 LT	259	while (--i >= 0)
	260	class_device_remove_file(&new_bd->class_dev,
	261	&bl_class_device_attributes[i]);
	262	class_device_unregister(&new_bd->class_dev);
	263	/* No need to kfree(new_bd) since release() method was called */
	264	return ERR_PTR(rc);
	265	}
	266	}
	267
321709c5 RP	268	#ifdef CONFIG_PMAC_BACKLIGHT
	269	mutex_lock(&pmac_backlight_mutex);
	270	if (!pmac_backlight)
	271	pmac_backlight = new_bd;
	272	mutex_unlock(&pmac_backlight_mutex);
	273	#endif
	274
1da177e4 LT	275	return new_bd;
	276	}
	277	EXPORT_SYMBOL(backlight_device_register);
	278
	279	/**
	280	* backlight_device_unregister - unregisters a backlight device object.
	281	* @bd: the backlight device object to be unregistered and freed.
	282	*
	283	* Unregisters a previously registered via backlight_device_register object.
	284	*/
	285	void backlight_device_unregister(struct backlight_device *bd)
	286	{
	287	int i;
	288
	289	if (!bd)
	290	return;
	291
	292	pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id);
	293
321709c5 RP	294	#ifdef CONFIG_PMAC_BACKLIGHT
	295	mutex_lock(&pmac_backlight_mutex);
	296	if (pmac_backlight == bd)
	297	pmac_backlight = NULL;
	298	mutex_unlock(&pmac_backlight_mutex);
	299	#endif
	300
1da177e4 LT	301	for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++)
	302	class_device_remove_file(&bd->class_dev,
	303	&bl_class_device_attributes[i]);
	304
249040dc	305	mutex_lock(&bd->props_lock);
1da177e4	306	bd->props = NULL;
249040dc	307	mutex_unlock(&bd->props_lock);
1da177e4	308
3d5eeadd	309	backlight_unregister_fb(bd);
1da177e4 LT	310
	311	class_device_unregister(&bd->class_dev);
	312	}
	313	EXPORT_SYMBOL(backlight_device_unregister);
	314
	315	static void __exit backlight_class_exit(void)
	316	{
	317	class_unregister(&backlight_class);
	318	}
	319
	320	static int __init backlight_class_init(void)
	321	{
	322	return class_register(&backlight_class);
	323	}
	324
	325	/*
	326	* if this is compiled into the kernel, we need to ensure that the
	327	* class is registered before users of the class try to register lcd's
	328	*/
	329	postcore_initcall(backlight_class_init);
	330	module_exit(backlight_class_exit);
	331
	332	MODULE_LICENSE("GPL");
	333	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	334	MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");