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