[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>

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 (likely(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 (likely(bd->props)) {
		pr_debug("backlight: set power to %d\n", power);
		bd->props->power = power;
		if (likely(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 (likely(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 (likely(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 (likely(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 (likely(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 (likely(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),
};

/* 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 =(struct fb_event *)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 (likely(bd->props && bd->props->update_status))
				bd->props->update_status(bd);
		}
	up(&bd->sem);
	return 0;
}

/**
 * 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, 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 (unlikely(!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;
	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 (unlikely(rc)) {
error:		kfree(new_bd);
		return ERR_PTR(rc);
	}

	memset(&new_bd->fb_notif, 0, sizeof(new_bd->fb_notif));
	new_bd->fb_notif.notifier_call = fb_notifier_callback;

	rc = fb_register_client(&new_bd->fb_notif);
	if (unlikely(rc))
		goto error;

	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 (unlikely(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);
	if (likely(bd->props && bd->props->update_status)) {
		bd->props->brightness = 0;
		bd->props->power = 0;
		bd->props->update_status(bd);
	}

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

	fb_unregister_client(&bd->fb_notif);

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