[net-next-2.6.git] / drivers / video / backlight / lcd.c

/*
 * LCD Lowlevel Control Abstraction
 *
 * Copyright (C) 2003,2004 Hewlett-Packard Company
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/lcd.h>
#include <linux/notifier.h>
#include <linux/ctype.h>
#include <linux/err.h>
#include <linux/fb.h>

#if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \
			   defined(CONFIG_LCD_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 lcd power as well ...
 */
static int fb_notifier_callback(struct notifier_block *self,
				 unsigned long event, void *data)
{
	struct lcd_device *ld;
	struct fb_event *evdata = data;

	/* If we aren't interested in this event, skip it immediately ... */
	if (event != FB_EVENT_BLANK)
		return 0;

	ld = container_of(self, struct lcd_device, fb_notif);
	down(&ld->sem);
	if (ld->props)
		if (!ld->props->check_fb || ld->props->check_fb(evdata->info))
			ld->props->set_power(ld, *(int *)evdata->data);
	up(&ld->sem);
	return 0;
}

static int lcd_register_fb(struct lcd_device *ld)
{
	memset(&ld->fb_notif, 0, sizeof(&ld->fb_notif));
	ld->fb_notif.notifier_call = fb_notifier_callback;
	return fb_register_client(&ld->fb_notif);
}

static void lcd_unregister_fb(struct lcd_device *ld)
{
	fb_unregister_client(&ld->fb_notif);
}
#else
static int lcd_register_fb(struct lcd_device *ld)
{
	return 0;
}

static inline void lcd_unregister_fb(struct lcd_device *ld)
{
}
#endif /* CONFIG_FB */

static ssize_t lcd_show_power(struct class_device *cdev, char *buf)
{
	int rc;
	struct lcd_device *ld = to_lcd_device(cdev);

	down(&ld->sem);
	if (likely(ld->props && ld->props->get_power))
		rc = sprintf(buf, "%d\n", ld->props->get_power(ld));
	else
		rc = -ENXIO;
	up(&ld->sem);

	return rc;
}

static ssize_t lcd_store_power(struct class_device *cdev, const char *buf, size_t count)
{
	int rc = -ENXIO;
	char *endp;
	struct lcd_device *ld = to_lcd_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(&ld->sem);
	if (likely(ld->props && ld->props->set_power)) {
		pr_debug("lcd: set power to %d\n", power);
		ld->props->set_power(ld, power);
		rc = count;
	}
	up(&ld->sem);

	return rc;
}

static ssize_t lcd_show_contrast(struct class_device *cdev, char *buf)
{
	int rc = -ENXIO;
	struct lcd_device *ld = to_lcd_device(cdev);

	down(&ld->sem);
	if (likely(ld->props && ld->props->get_contrast))
		rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld));
	up(&ld->sem);

	return rc;
}

static ssize_t lcd_store_contrast(struct class_device *cdev, const char *buf, size_t count)
{
	int rc = -ENXIO;
	char *endp;
	struct lcd_device *ld = to_lcd_device(cdev);
	int contrast = simple_strtoul(buf, &endp, 0);
	size_t size = endp - buf;

	if (*endp && isspace(*endp))
		size++;
	if (size != count)
		return -EINVAL;

	down(&ld->sem);
	if (likely(ld->props && ld->props->set_contrast)) {
		pr_debug("lcd: set contrast to %d\n", contrast);
		ld->props->set_contrast(ld, contrast);
		rc = count;
	}
	up(&ld->sem);

	return rc;
}

static ssize_t lcd_show_max_contrast(struct class_device *cdev, char *buf)
{
	int rc = -ENXIO;
	struct lcd_device *ld = to_lcd_device(cdev);

	down(&ld->sem);
	if (likely(ld->props))
		rc = sprintf(buf, "%d\n", ld->props->max_contrast);
	up(&ld->sem);

	return rc;
}

static void lcd_class_release(struct class_device *dev)
{
	struct lcd_device *ld = to_lcd_device(dev);
	kfree(ld);
}

static struct class lcd_class = {
	.name = "lcd",
	.release = lcd_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 lcd_class_device_attributes[] = {
	DECLARE_ATTR(power, 0644, lcd_show_power, lcd_store_power),
	DECLARE_ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	DECLARE_ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
};

/**
 * lcd_device_register - register a new object of lcd_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(ld->class_dev).
 * @lp: the lcd properties structure.
 *
 * Creates and registers a new lcd class_device. Returns either an ERR_PTR()
 * or a pointer to the newly allocated device.
 */
struct lcd_device *lcd_device_register(const char *name, void *devdata,
				       struct lcd_properties *lp)
{
	int i, rc;
	struct lcd_device *new_ld;

	pr_debug("lcd_device_register: name=%s\n", name);

	new_ld = kmalloc(sizeof(struct lcd_device), GFP_KERNEL);
	if (unlikely(!new_ld))
		return ERR_PTR(-ENOMEM);

	init_MUTEX(&new_ld->sem);
	new_ld->props = lp;
	memset(&new_ld->class_dev, 0, sizeof(new_ld->class_dev));
	new_ld->class_dev.class = &lcd_class;
	strlcpy(new_ld->class_dev.class_id, name, KOBJ_NAME_LEN);
	class_set_devdata(&new_ld->class_dev, devdata);

	rc = class_device_register(&new_ld->class_dev);
	if (unlikely(rc)) {
error:		kfree(new_ld);
		return ERR_PTR(rc);
	}

	rc = lcd_register_fb(new_ld);

	if (unlikely(rc))
		goto error;

	for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++) {
		rc = class_device_create_file(&new_ld->class_dev,
					      &lcd_class_device_attributes[i]);
		if (unlikely(rc)) {
			while (--i >= 0)
				class_device_remove_file(&new_ld->class_dev,
							 &lcd_class_device_attributes[i]);
			class_device_unregister(&new_ld->class_dev);
			/* No need to kfree(new_ld) since release() method was called */
			return ERR_PTR(rc);
		}
	}

	return new_ld;
}
EXPORT_SYMBOL(lcd_device_register);

/**
 * lcd_device_unregister - unregisters a object of lcd_device class.
 * @ld: the lcd device object to be unregistered and freed.
 *
 * Unregisters a previously registered via lcd_device_register object.
 */
void lcd_device_unregister(struct lcd_device *ld)
{
	int i;

	if (!ld)
		return;

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

	for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++)
		class_device_remove_file(&ld->class_dev,
					 &lcd_class_device_attributes[i]);

	down(&ld->sem);
	ld->props = NULL;
	up(&ld->sem);
	lcd_unregister_fb(ld);
	class_device_unregister(&ld->class_dev);
}
EXPORT_SYMBOL(lcd_device_unregister);

static void __exit lcd_class_exit(void)
{
	class_unregister(&lcd_class);
}

static int __init lcd_class_init(void)
{
	return class_register(&lcd_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(lcd_class_init);
module_exit(lcd_class_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* LCD 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/lcd.h>
	12	#include <linux/notifier.h>
	13	#include <linux/ctype.h>
	14	#include <linux/err.h>
	15	#include <linux/fb.h>
1da177e4	16
3d5eeadd JS	17	#if defined(CONFIG_FB) \|\| (defined(CONFIG_FB_MODULE) && \
	18	defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
	19	/* This callback gets called when something important happens inside a
	20	* framebuffer driver. We're looking if that important event is blanking,
	21	* and if it is, we're switching lcd power as well ...
	22	*/
	23	static int fb_notifier_callback(struct notifier_block *self,
	24	unsigned long event, void *data)
	25	{
	26	struct lcd_device *ld;
	27	struct fb_event *evdata = data;
	28
	29	/* If we aren't interested in this event, skip it immediately ... */
	30	if (event != FB_EVENT_BLANK)
	31	return 0;
	32
	33	ld = container_of(self, struct lcd_device, fb_notif);
	34	down(&ld->sem);
	35	if (ld->props)
	36	if (!ld->props->check_fb \|\| ld->props->check_fb(evdata->info))
	37	ld->props->set_power(ld, (int )evdata->data);
	38	up(&ld->sem);
	39	return 0;
	40	}
	41
	42	static int lcd_register_fb(struct lcd_device *ld)
	43	{
	44	memset(&ld->fb_notif, 0, sizeof(&ld->fb_notif));
	45	ld->fb_notif.notifier_call = fb_notifier_callback;
	46	return fb_register_client(&ld->fb_notif);
	47	}
	48
	49	static void lcd_unregister_fb(struct lcd_device *ld)
	50	{
	51	fb_unregister_client(&ld->fb_notif);
	52	}
	53	#else
	54	static int lcd_register_fb(struct lcd_device *ld)
	55	{
	56	return 0;
	57	}
	58
	59	static inline void lcd_unregister_fb(struct lcd_device *ld)
	60	{
	61	}
	62	#endif /* CONFIG_FB */
	63
1da177e4 LT	64	static ssize_t lcd_show_power(struct class_device cdev, char buf)
	65	{
	66	int rc;
	67	struct lcd_device *ld = to_lcd_device(cdev);
	68
	69	down(&ld->sem);
	70	if (likely(ld->props && ld->props->get_power))
	71	rc = sprintf(buf, "%d\n", ld->props->get_power(ld));
	72	else
	73	rc = -ENXIO;
	74	up(&ld->sem);
	75
	76	return rc;
	77	}
	78
	79	static ssize_t lcd_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 lcd_device *ld = to_lcd_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;
	91
	92	down(&ld->sem);
	93	if (likely(ld->props && ld->props->set_power)) {
	94	pr_debug("lcd: set power to %d\n", power);
	95	ld->props->set_power(ld, power);
	96	rc = count;
68673afd	97	}
1da177e4 LT	98	up(&ld->sem);
	99
	100	return rc;
	101	}
	102
	103	static ssize_t lcd_show_contrast(struct class_device cdev, char buf)
	104	{
68673afd	105	int rc = -ENXIO;
1da177e4 LT	106	struct lcd_device *ld = to_lcd_device(cdev);
	107
	108	down(&ld->sem);
	109	if (likely(ld->props && ld->props->get_contrast))
	110	rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld));
1da177e4 LT	111	up(&ld->sem);
	112
	113	return rc;
	114	}
	115
	116	static ssize_t lcd_store_contrast(struct class_device cdev, const char buf, size_t count)
	117	{
68673afd	118	int rc = -ENXIO;
1da177e4 LT	119	char *endp;
1da177e4 LT	120	struct lcd_device *ld = to_lcd_device(cdev);
68673afd RP	121	int contrast = simple_strtoul(buf, &endp, 0);
68673afd RP	122	size_t size = endp - buf;
1da177e4	123
68673afd RP	124	if (endp && isspace(endp))
	125	size++;
	126	if (size != count)
1da177e4 LT	127	return -EINVAL;
	128
	129	down(&ld->sem);
	130	if (likely(ld->props && ld->props->set_contrast)) {
	131	pr_debug("lcd: set contrast to %d\n", contrast);
	132	ld->props->set_contrast(ld, contrast);
	133	rc = count;
68673afd	134	}
1da177e4 LT	135	up(&ld->sem);
	136
	137	return rc;
	138	}
	139
	140	static ssize_t lcd_show_max_contrast(struct class_device cdev, char buf)
	141	{
68673afd	142	int rc = -ENXIO;
1da177e4 LT	143	struct lcd_device *ld = to_lcd_device(cdev);
	144
	145	down(&ld->sem);
	146	if (likely(ld->props))
	147	rc = sprintf(buf, "%d\n", ld->props->max_contrast);
1da177e4 LT	148	up(&ld->sem);
	149
	150	return rc;
	151	}
	152
	153	static void lcd_class_release(struct class_device *dev)
	154	{
	155	struct lcd_device *ld = to_lcd_device(dev);
	156	kfree(ld);
	157	}
	158
	159	static struct class lcd_class = {
	160	.name = "lcd",
	161	.release = lcd_class_release,
	162	};
	163
	164	#define DECLARE_ATTR(_name,_mode,_show,_store) \
	165	{ \
	166	.attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \
	167	.show = _show, \
	168	.store = _store, \
	169	}
	170
d95159cf	171	static const struct class_device_attribute lcd_class_device_attributes[] = {
1da177e4 LT	172	DECLARE_ATTR(power, 0644, lcd_show_power, lcd_store_power),
	173	DECLARE_ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	174	DECLARE_ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
	175	};
	176
1da177e4 LT	177	/**
	178	* lcd_device_register - register a new object of lcd_device class.
	179	* @name: the name of the new object(must be the same as the name of the
	180	* respective framebuffer device).
	181	* @devdata: an optional pointer to be stored in the class_device. The
	182	* methods may retrieve it by using class_get_devdata(ld->class_dev).
	183	* @lp: the lcd properties structure.
	184	*
	185	* Creates and registers a new lcd class_device. Returns either an ERR_PTR()
	186	* or a pointer to the newly allocated device.
	187	*/
	188	struct lcd_device lcd_device_register(const char name, void *devdata,
	189	struct lcd_properties *lp)
	190	{
	191	int i, rc;
	192	struct lcd_device *new_ld;
	193
	194	pr_debug("lcd_device_register: name=%s\n", name);
	195
	196	new_ld = kmalloc(sizeof(struct lcd_device), GFP_KERNEL);
	197	if (unlikely(!new_ld))
10ad1b73	198	return ERR_PTR(-ENOMEM);
1da177e4 LT	199
	200	init_MUTEX(&new_ld->sem);
	201	new_ld->props = lp;
	202	memset(&new_ld->class_dev, 0, sizeof(new_ld->class_dev));
	203	new_ld->class_dev.class = &lcd_class;
	204	strlcpy(new_ld->class_dev.class_id, name, KOBJ_NAME_LEN);
	205	class_set_devdata(&new_ld->class_dev, devdata);
	206
	207	rc = class_device_register(&new_ld->class_dev);
	208	if (unlikely(rc)) {
	209	error: kfree(new_ld);
	210	return ERR_PTR(rc);
	211	}
	212
3d5eeadd	213	rc = lcd_register_fb(new_ld);
1da177e4	214
1da177e4 LT	215	if (unlikely(rc))
	216	goto error;
	217
	218	for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++) {
	219	rc = class_device_create_file(&new_ld->class_dev,
	220	&lcd_class_device_attributes[i]);
	221	if (unlikely(rc)) {
	222	while (--i >= 0)
	223	class_device_remove_file(&new_ld->class_dev,
	224	&lcd_class_device_attributes[i]);
	225	class_device_unregister(&new_ld->class_dev);
	226	/* No need to kfree(new_ld) since release() method was called */
	227	return ERR_PTR(rc);
	228	}
	229	}
	230
	231	return new_ld;
	232	}
	233	EXPORT_SYMBOL(lcd_device_register);
	234
	235	/**
	236	* lcd_device_unregister - unregisters a object of lcd_device class.
	237	* @ld: the lcd device object to be unregistered and freed.
	238	*
	239	* Unregisters a previously registered via lcd_device_register object.
	240	*/
	241	void lcd_device_unregister(struct lcd_device *ld)
	242	{
	243	int i;
	244
	245	if (!ld)
	246	return;
	247
	248	pr_debug("lcd_device_unregister: name=%s\n", ld->class_dev.class_id);
	249
	250	for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++)
	251	class_device_remove_file(&ld->class_dev,
	252	&lcd_class_device_attributes[i]);
	253
	254	down(&ld->sem);
	255	ld->props = NULL;
	256	up(&ld->sem);
3d5eeadd	257	lcd_unregister_fb(ld);
1da177e4 LT	258	class_device_unregister(&ld->class_dev);
	259	}
	260	EXPORT_SYMBOL(lcd_device_unregister);
	261
	262	static void __exit lcd_class_exit(void)
	263	{
	264	class_unregister(&lcd_class);
	265	}
	266
	267	static int __init lcd_class_init(void)
	268	{
	269	return class_register(&lcd_class);
	270	}
	271
	272	/*
	273	* if this is compiled into the kernel, we need to ensure that the
	274	* class is registered before users of the class try to register lcd's
	275	*/
	276	postcore_initcall(lcd_class_init);
	277	module_exit(lcd_class_exit);
	278
	279	MODULE_LICENSE("GPL");
	280	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	281	MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");