[net-next-2.6.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;
			if (bd->props.fb_blank == FB_BLANK_UNBLANK)
				bd->props.state &= ~BL_CORE_FBBLANK;
			else
				bd->props.state |= BL_CORE_FBBLANK;
			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 device *dev,
		struct device_attribute *attr,char *buf)
{
	struct backlight_device *bd = to_backlight_device(dev);

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

static ssize_t backlight_store_power(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	int rc;
	struct backlight_device *bd = to_backlight_device(dev);
	unsigned long power;

	rc = strict_strtoul(buf, 0, &power);
	if (rc)
		return rc;

	rc = -ENXIO;
	mutex_lock(&bd->ops_lock);
	if (bd->ops) {
		pr_debug("backlight: set power to %lu\n", power);
		if (bd->props.power != 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 device *dev,
		struct device_attribute *attr, char *buf)
{
	struct backlight_device *bd = to_backlight_device(dev);

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

static ssize_t backlight_store_brightness(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	int rc;
	struct backlight_device *bd = to_backlight_device(dev);
	unsigned long brightness;

	rc = strict_strtoul(buf, 0, &brightness);
	if (rc)
		return rc;

	rc = -ENXIO;

	mutex_lock(&bd->ops_lock);
	if (bd->ops) {
		if (brightness > bd->props.max_brightness)
			rc = -EINVAL;
		else {
			pr_debug("backlight: set brightness to %lu\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 device *dev,
		struct device_attribute *attr, char *buf)
{
	struct backlight_device *bd = to_backlight_device(dev);

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

static ssize_t backlight_show_actual_brightness(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	int rc = -ENXIO;
	struct backlight_device *bd = to_backlight_device(dev);

	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 struct class *backlight_class;

static int backlight_suspend(struct device *dev, pm_message_t state)
{
	struct backlight_device *bd = to_backlight_device(dev);

	if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
		mutex_lock(&bd->ops_lock);
		bd->props.state |= BL_CORE_SUSPENDED;
		backlight_update_status(bd);
		mutex_unlock(&bd->ops_lock);
	}

	return 0;
}

static int backlight_resume(struct device *dev)
{
	struct backlight_device *bd = to_backlight_device(dev);

	if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
		mutex_lock(&bd->ops_lock);
		bd->props.state &= ~BL_CORE_SUSPENDED;
		backlight_update_status(bd);
		mutex_unlock(&bd->ops_lock);
	}

	return 0;
}

static void bl_device_release(struct device *dev)
{
	struct backlight_device *bd = to_backlight_device(dev);
	kfree(bd);
}

static struct device_attribute bl_device_attributes[] = {
	__ATTR(bl_power, 0644, backlight_show_power, backlight_store_power),
	__ATTR(brightness, 0644, backlight_show_brightness,
		     backlight_store_brightness),
	__ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
		     NULL),
	__ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
	__ATTR_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).
 * @parent: a pointer to the parent device
 * @devdata: an optional pointer to be stored for private driver use. The
 *   methods may retrieve it by using bl_get_data(bd).
 * @ops: the backlight operations structure.
 *
 * Creates and registers new backlight 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 *parent, void *devdata, struct backlight_ops *ops)
{
	struct backlight_device *new_bd;
	int rc;

	pr_debug("backlight_device_register: 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->dev.class = backlight_class;
	new_bd->dev.parent = parent;
	new_bd->dev.release = bl_device_release;
	dev_set_name(&new_bd->dev, name);
	dev_set_drvdata(&new_bd->dev, devdata);

	rc = device_register(&new_bd->dev);
	if (rc) {
		kfree(new_bd);
		return ERR_PTR(rc);
	}

	rc = backlight_register_fb(new_bd);
	if (rc) {
		device_unregister(&new_bd->dev);
		return ERR_PTR(rc);
	}

	new_bd->ops = ops;

#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)
{
	if (!bd)
		return;

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

	backlight_unregister_fb(bd);
	device_unregister(&bd->dev);
}
EXPORT_SYMBOL(backlight_device_unregister);

static void __exit backlight_class_exit(void)
{
	class_destroy(backlight_class);
}

static int __init backlight_class_init(void)
{
	backlight_class = class_create(THIS_MODULE, "backlight");
	if (IS_ERR(backlight_class)) {
		printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
				PTR_ERR(backlight_class));
		return PTR_ERR(backlight_class);
	}

	backlight_class->dev_attrs = bl_device_attributes;
	backlight_class->suspend = backlight_suspend;
	backlight_class->resume = backlight_resume;
	return 0;
}

/*
 * 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;
c835ee7f RP	43	if (bd->props.fb_blank == FB_BLANK_UNBLANK)
	44	bd->props.state &= ~BL_CORE_FBBLANK;
	45	else
	46	bd->props.state \|= BL_CORE_FBBLANK;
28ee086d	47	backlight_update_status(bd);
3d5eeadd	48	}
599a52d1	49	mutex_unlock(&bd->ops_lock);
3d5eeadd JS	50	return 0;
	51	}
	52
	53	static int backlight_register_fb(struct backlight_device *bd)
	54	{
	55	memset(&bd->fb_notif, 0, sizeof(bd->fb_notif));
	56	bd->fb_notif.notifier_call = fb_notifier_callback;
	57
	58	return fb_register_client(&bd->fb_notif);
	59	}
	60
	61	static void backlight_unregister_fb(struct backlight_device *bd)
	62	{
	63	fb_unregister_client(&bd->fb_notif);
	64	}
	65	#else
	66	static inline int backlight_register_fb(struct backlight_device *bd)
	67	{
	68	return 0;
	69	}
	70
	71	static inline void backlight_unregister_fb(struct backlight_device *bd)
	72	{
	73	}
	74	#endif /* CONFIG_FB */
	75
655bfd7a RP	76	static ssize_t backlight_show_power(struct device *dev,
655bfd7a RP	77	struct device_attribute attr,char buf)
1da177e4	78	{
655bfd7a	79	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	80
599a52d1	81	return sprintf(buf, "%d\n", bd->props.power);
1da177e4 LT	82	}
1da177e4 LT	83
655bfd7a RP	84	static ssize_t backlight_store_power(struct device *dev,
655bfd7a RP	85	struct device_attribute attr, const char buf, size_t count)
1da177e4	86	{
9a2c61a9	87	int rc;
655bfd7a	88	struct backlight_device *bd = to_backlight_device(dev);
9a2c61a9	89	unsigned long power;
1da177e4	90
9a2c61a9 PM	91	rc = strict_strtoul(buf, 0, &power);
	92	if (rc)
	93	return rc;
1da177e4	94
9a2c61a9	95	rc = -ENXIO;
599a52d1 RP	96	mutex_lock(&bd->ops_lock);
599a52d1 RP	97	if (bd->ops) {
9a2c61a9	98	pr_debug("backlight: set power to %lu\n", power);
51552453 HD	99	if (bd->props.power != power) {
	100	bd->props.power = power;
	101	backlight_update_status(bd);
	102	}
1da177e4	103	rc = count;
6ca01765	104	}
599a52d1	105	mutex_unlock(&bd->ops_lock);
1da177e4 LT	106
	107	return rc;
	108	}
	109
655bfd7a RP	110	static ssize_t backlight_show_brightness(struct device *dev,
655bfd7a RP	111	struct device_attribute attr, char buf)
1da177e4	112	{
655bfd7a	113	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	114
599a52d1	115	return sprintf(buf, "%d\n", bd->props.brightness);
1da177e4 LT	116	}
1da177e4 LT	117
655bfd7a RP	118	static ssize_t backlight_store_brightness(struct device *dev,
655bfd7a RP	119	struct device_attribute attr, const char buf, size_t count)
1da177e4	120	{
9a2c61a9	121	int rc;
655bfd7a	122	struct backlight_device *bd = to_backlight_device(dev);
9a2c61a9	123	unsigned long brightness;
1da177e4	124
9a2c61a9 PM	125	rc = strict_strtoul(buf, 0, &brightness);
	126	if (rc)
	127	return rc;
	128
	129	rc = -ENXIO;
1da177e4	130
599a52d1 RP	131	mutex_lock(&bd->ops_lock);
	132	if (bd->ops) {
	133	if (brightness > bd->props.max_brightness)
6ca01765 RP	134	rc = -EINVAL;
6ca01765 RP	135	else {
9a2c61a9	136	pr_debug("backlight: set brightness to %lu\n",
6ca01765	137	brightness);
9be1df98 ZR	138	bd->props.brightness = brightness;
9be1df98 ZR	139	backlight_update_status(bd);
6ca01765 RP	140	rc = count;
	141	}
	142	}
599a52d1	143	mutex_unlock(&bd->ops_lock);
1da177e4 LT	144
	145	return rc;
	146	}
	147
655bfd7a RP	148	static ssize_t backlight_show_max_brightness(struct device *dev,
655bfd7a RP	149	struct device_attribute attr, char buf)
1da177e4	150	{
655bfd7a	151	struct backlight_device *bd = to_backlight_device(dev);
1da177e4	152
599a52d1	153	return sprintf(buf, "%d\n", bd->props.max_brightness);
6ca01765 RP	154	}
6ca01765 RP	155
655bfd7a RP	156	static ssize_t backlight_show_actual_brightness(struct device *dev,
655bfd7a RP	157	struct device_attribute attr, char buf)
6ca01765 RP	158	{
6ca01765 RP	159	int rc = -ENXIO;
655bfd7a	160	struct backlight_device *bd = to_backlight_device(dev);
6ca01765	161
599a52d1 RP	162	mutex_lock(&bd->ops_lock);
	163	if (bd->ops && bd->ops->get_brightness)
	164	rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
	165	mutex_unlock(&bd->ops_lock);
1da177e4 LT	166
	167	return rc;
	168	}
	169
0ad90efd	170	static struct class *backlight_class;
655bfd7a	171
c835ee7f RP	172	static int backlight_suspend(struct device *dev, pm_message_t state)
	173	{
	174	struct backlight_device *bd = to_backlight_device(dev);
	175
	176	if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
	177	mutex_lock(&bd->ops_lock);
	178	bd->props.state \|= BL_CORE_SUSPENDED;
	179	backlight_update_status(bd);
	180	mutex_unlock(&bd->ops_lock);
	181	}
	182
	183	return 0;
	184	}
	185
	186	static int backlight_resume(struct device *dev)
	187	{
	188	struct backlight_device *bd = to_backlight_device(dev);
	189
	190	if (bd->ops->options & BL_CORE_SUSPENDRESUME) {
	191	mutex_lock(&bd->ops_lock);
	192	bd->props.state &= ~BL_CORE_SUSPENDED;
	193	backlight_update_status(bd);
	194	mutex_unlock(&bd->ops_lock);
	195	}
	196
	197	return 0;
	198	}
	199
655bfd7a	200	static void bl_device_release(struct device *dev)
1da177e4 LT	201	{
	202	struct backlight_device *bd = to_backlight_device(dev);
	203	kfree(bd);
	204	}
	205
655bfd7a RP	206	static struct device_attribute bl_device_attributes[] = {
	207	__ATTR(bl_power, 0644, backlight_show_power, backlight_store_power),
	208	__ATTR(brightness, 0644, backlight_show_brightness,
6ca01765	209	backlight_store_brightness),
655bfd7a	210	__ATTR(actual_brightness, 0444, backlight_show_actual_brightness,
6ca01765	211	NULL),
655bfd7a RP	212	__ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL),
655bfd7a RP	213	__ATTR_NULL,
1da177e4 LT	214	};
1da177e4 LT	215
1da177e4 LT	216	/**
	217	* backlight_device_register - create and register a new object of
	218	* backlight_device class.
	219	* @name: the name of the new object(must be the same as the name of the
	220	* respective framebuffer device).
f6ec2d96	221	* @parent: a pointer to the parent device
655bfd7a RP	222	* @devdata: an optional pointer to be stored for private driver use. The
655bfd7a RP	223	* methods may retrieve it by using bl_get_data(bd).
599a52d1	224	* @ops: the backlight operations structure.
1da177e4	225	*
655bfd7a	226	* Creates and registers new backlight device. Returns either an
1da177e4 LT	227	* ERR_PTR() or a pointer to the newly allocated device.
1da177e4 LT	228	*/
519ab5f2	229	struct backlight_device backlight_device_register(const char name,
655bfd7a	230	struct device parent, void devdata, struct backlight_ops *ops)
1da177e4	231	{
1da177e4	232	struct backlight_device *new_bd;
655bfd7a	233	int rc;
1da177e4	234
655bfd7a	235	pr_debug("backlight_device_register: name=%s\n", name);
1da177e4	236
599a52d1	237	new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL);
90968e8e	238	if (!new_bd)
10ad1b73	239	return ERR_PTR(-ENOMEM);
1da177e4	240
28ee086d	241	mutex_init(&new_bd->update_lock);
599a52d1	242	mutex_init(&new_bd->ops_lock);
1da177e4	243
655bfd7a RP	244	new_bd->dev.class = backlight_class;
	245	new_bd->dev.parent = parent;
	246	new_bd->dev.release = bl_device_release;
64dba9a9	247	dev_set_name(&new_bd->dev, name);
655bfd7a RP	248	dev_set_drvdata(&new_bd->dev, devdata);
	249
	250	rc = device_register(&new_bd->dev);
90968e8e	251	if (rc) {
2fd5a154	252	kfree(new_bd);
1da177e4 LT	253	return ERR_PTR(rc);
	254	}
	255
3d5eeadd	256	rc = backlight_register_fb(new_bd);
2fd5a154	257	if (rc) {
655bfd7a	258	device_unregister(&new_bd->dev);
2fd5a154 DT	259	return ERR_PTR(rc);
	260	}
	261
655bfd7a	262	new_bd->ops = ops;
1da177e4	263
321709c5 RP	264	#ifdef CONFIG_PMAC_BACKLIGHT
	265	mutex_lock(&pmac_backlight_mutex);
	266	if (!pmac_backlight)
	267	pmac_backlight = new_bd;
	268	mutex_unlock(&pmac_backlight_mutex);
	269	#endif
	270
1da177e4 LT	271	return new_bd;
	272	}
	273	EXPORT_SYMBOL(backlight_device_register);
	274
	275	/**
	276	* backlight_device_unregister - unregisters a backlight device object.
	277	* @bd: the backlight device object to be unregistered and freed.
	278	*
	279	* Unregisters a previously registered via backlight_device_register object.
	280	*/
	281	void backlight_device_unregister(struct backlight_device *bd)
	282	{
1da177e4 LT	283	if (!bd)
	284	return;
	285
321709c5 RP	286	#ifdef CONFIG_PMAC_BACKLIGHT
	287	mutex_lock(&pmac_backlight_mutex);
	288	if (pmac_backlight == bd)
	289	pmac_backlight = NULL;
	290	mutex_unlock(&pmac_backlight_mutex);
	291	#endif
599a52d1 RP	292	mutex_lock(&bd->ops_lock);
	293	bd->ops = NULL;
	294	mutex_unlock(&bd->ops_lock);
1da177e4	295
3d5eeadd	296	backlight_unregister_fb(bd);
655bfd7a	297	device_unregister(&bd->dev);
1da177e4 LT	298	}
	299	EXPORT_SYMBOL(backlight_device_unregister);
	300
	301	static void __exit backlight_class_exit(void)
	302	{
655bfd7a	303	class_destroy(backlight_class);
1da177e4 LT	304	}
	305
	306	static int __init backlight_class_init(void)
	307	{
655bfd7a RP	308	backlight_class = class_create(THIS_MODULE, "backlight");
	309	if (IS_ERR(backlight_class)) {
	310	printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
	311	PTR_ERR(backlight_class));
	312	return PTR_ERR(backlight_class);
	313	}
	314
	315	backlight_class->dev_attrs = bl_device_attributes;
c835ee7f RP	316	backlight_class->suspend = backlight_suspend;
c835ee7f RP	317	backlight_class->resume = backlight_resume;
655bfd7a	318	return 0;
1da177e4 LT	319	}
	320
	321	/*
	322	* if this is compiled into the kernel, we need to ensure that the
	323	* class is registered before users of the class try to register lcd's
	324	*/
	325	postcore_initcall(backlight_class_init);
	326	module_exit(backlight_class_exit);
	327
	328	MODULE_LICENSE("GPL");
	329	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	330	MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction");