[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>
#include <linux/slab.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 ... */
	switch (event) {
	case FB_EVENT_BLANK:
	case FB_EVENT_MODE_CHANGE:
	case FB_EVENT_MODE_CHANGE_ALL:
		break;
	default:
		return 0;
	}

	ld = container_of(self, struct lcd_device, fb_notif);
	if (!ld->ops)
		return 0;

	mutex_lock(&ld->ops_lock);
	if (!ld->ops->check_fb || ld->ops->check_fb(ld, evdata->info)) {
		if (event == FB_EVENT_BLANK) {
			if (ld->ops->set_power)
				ld->ops->set_power(ld, *(int *)evdata->data);
		} else {
			if (ld->ops->set_mode)
				ld->ops->set_mode(ld, evdata->data);
		}
	}
	mutex_unlock(&ld->ops_lock);
	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 device *dev, struct device_attribute *attr,
		char *buf)
{
	int rc;
	struct lcd_device *ld = to_lcd_device(dev);

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->get_power)
		rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
	else
		rc = -ENXIO;
	mutex_unlock(&ld->ops_lock);

	return rc;
}

static ssize_t lcd_store_power(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	int rc = -ENXIO;
	char *endp;
	struct lcd_device *ld = to_lcd_device(dev);
	int power = simple_strtoul(buf, &endp, 0);
	size_t size = endp - buf;

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

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->set_power) {
		pr_debug("lcd: set power to %d\n", power);
		ld->ops->set_power(ld, power);
		rc = count;
	}
	mutex_unlock(&ld->ops_lock);

	return rc;
}

static ssize_t lcd_show_contrast(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	int rc = -ENXIO;
	struct lcd_device *ld = to_lcd_device(dev);

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->get_contrast)
		rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
	mutex_unlock(&ld->ops_lock);

	return rc;
}

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

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

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->set_contrast) {
		pr_debug("lcd: set contrast to %d\n", contrast);
		ld->ops->set_contrast(ld, contrast);
		rc = count;
	}
	mutex_unlock(&ld->ops_lock);

	return rc;
}

static ssize_t lcd_show_max_contrast(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct lcd_device *ld = to_lcd_device(dev);

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

static struct class *lcd_class;

static void lcd_device_release(struct device *dev)
{
	struct lcd_device *ld = to_lcd_device(dev);
	kfree(ld);
}

static struct device_attribute lcd_device_attributes[] = {
	__ATTR(lcd_power, 0644, lcd_show_power, lcd_store_power),
	__ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	__ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
	__ATTR_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 device. The
 *   methods may retrieve it by using lcd_get_data(ld).
 * @ops: the lcd operations structure.
 *
 * Creates and registers a new lcd device. Returns either an ERR_PTR()
 * or a pointer to the newly allocated device.
 */
struct lcd_device *lcd_device_register(const char *name, struct device *parent,
		void *devdata, struct lcd_ops *ops)
{
	struct lcd_device *new_ld;
	int rc;

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

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

	mutex_init(&new_ld->ops_lock);
	mutex_init(&new_ld->update_lock);

	new_ld->dev.class = lcd_class;
	new_ld->dev.parent = parent;
	new_ld->dev.release = lcd_device_release;
	dev_set_name(&new_ld->dev, name);
	dev_set_drvdata(&new_ld->dev, devdata);

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

	rc = lcd_register_fb(new_ld);
	if (rc) {
		device_unregister(&new_ld->dev);
		return ERR_PTR(rc);
	}

	new_ld->ops = ops;

	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)
{
	if (!ld)
		return;

	mutex_lock(&ld->ops_lock);
	ld->ops = NULL;
	mutex_unlock(&ld->ops_lock);
	lcd_unregister_fb(ld);

	device_unregister(&ld->dev);
}
EXPORT_SYMBOL(lcd_device_unregister);

static void __exit lcd_class_exit(void)
{
	class_destroy(lcd_class);
}

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

	lcd_class->dev_attrs = lcd_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(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>
5a0e3ad6	16	#include <linux/slab.h>
1da177e4	17
3d5eeadd JS	18	#if defined(CONFIG_FB) \|\| (defined(CONFIG_FB_MODULE) && \
	19	defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
	20	/* This callback gets called when something important happens inside a
	21	* framebuffer driver. We're looking if that important event is blanking,
	22	* and if it is, we're switching lcd power as well ...
	23	*/
	24	static int fb_notifier_callback(struct notifier_block *self,
	25	unsigned long event, void *data)
	26	{
	27	struct lcd_device *ld;
	28	struct fb_event *evdata = data;
	29
	30	/* If we aren't interested in this event, skip it immediately ... */
faa312da EM	31	switch (event) {
	32	case FB_EVENT_BLANK:
	33	case FB_EVENT_MODE_CHANGE:
	34	case FB_EVENT_MODE_CHANGE_ALL:
	35	break;
	36	default:
3d5eeadd	37	return 0;
faa312da	38	}
3d5eeadd JS	39
3d5eeadd JS	40	ld = container_of(self, struct lcd_device, fb_notif);
faa312da EM	41	if (!ld->ops)
	42	return 0;
	43
599a52d1	44	mutex_lock(&ld->ops_lock);
faa312da	45	if (!ld->ops->check_fb \|\| ld->ops->check_fb(ld, evdata->info)) {
b3b4dc88 BD	46	if (event == FB_EVENT_BLANK) {
	47	if (ld->ops->set_power)
	48	ld->ops->set_power(ld, (int )evdata->data);
	49	} else {
	50	if (ld->ops->set_mode)
	51	ld->ops->set_mode(ld, evdata->data);
	52	}
faa312da	53	}
599a52d1	54	mutex_unlock(&ld->ops_lock);
3d5eeadd JS	55	return 0;
	56	}
	57
	58	static int lcd_register_fb(struct lcd_device *ld)
	59	{
1e0fa6bd	60	memset(&ld->fb_notif, 0, sizeof(ld->fb_notif));
3d5eeadd JS	61	ld->fb_notif.notifier_call = fb_notifier_callback;
	62	return fb_register_client(&ld->fb_notif);
	63	}
	64
	65	static void lcd_unregister_fb(struct lcd_device *ld)
	66	{
	67	fb_unregister_client(&ld->fb_notif);
	68	}
	69	#else
	70	static int lcd_register_fb(struct lcd_device *ld)
	71	{
	72	return 0;
	73	}
	74
	75	static inline void lcd_unregister_fb(struct lcd_device *ld)
	76	{
	77	}
	78	#endif /* CONFIG_FB */
	79
655bfd7a RP	80	static ssize_t lcd_show_power(struct device dev, struct device_attribute attr,
655bfd7a RP	81	char *buf)
1da177e4 LT	82	{
1da177e4 LT	83	int rc;
655bfd7a	84	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	85
599a52d1 RP	86	mutex_lock(&ld->ops_lock);
	87	if (ld->ops && ld->ops->get_power)
	88	rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
1da177e4 LT	89	else
1da177e4 LT	90	rc = -ENXIO;
599a52d1	91	mutex_unlock(&ld->ops_lock);
1da177e4 LT	92
	93	return rc;
	94	}
	95
655bfd7a RP	96	static ssize_t lcd_store_power(struct device *dev,
655bfd7a RP	97	struct device_attribute attr, const char buf, size_t count)
1da177e4	98	{
68673afd	99	int rc = -ENXIO;
1da177e4	100	char *endp;
655bfd7a	101	struct lcd_device *ld = to_lcd_device(dev);
68673afd RP	102	int power = simple_strtoul(buf, &endp, 0);
68673afd RP	103	size_t size = endp - buf;
1da177e4	104
e7d2860b	105	if (isspace(*endp))
68673afd RP	106	size++;
68673afd RP	107	if (size != count)
1da177e4 LT	108	return -EINVAL;
1da177e4 LT	109
599a52d1 RP	110	mutex_lock(&ld->ops_lock);
599a52d1 RP	111	if (ld->ops && ld->ops->set_power) {
1da177e4	112	pr_debug("lcd: set power to %d\n", power);
599a52d1	113	ld->ops->set_power(ld, power);
1da177e4	114	rc = count;
68673afd	115	}
599a52d1	116	mutex_unlock(&ld->ops_lock);
1da177e4 LT	117
	118	return rc;
	119	}
	120
655bfd7a RP	121	static ssize_t lcd_show_contrast(struct device *dev,
655bfd7a RP	122	struct device_attribute attr, char buf)
1da177e4	123	{
68673afd	124	int rc = -ENXIO;
655bfd7a	125	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	126
599a52d1 RP	127	mutex_lock(&ld->ops_lock);
	128	if (ld->ops && ld->ops->get_contrast)
	129	rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
	130	mutex_unlock(&ld->ops_lock);
1da177e4 LT	131
	132	return rc;
	133	}
	134
655bfd7a RP	135	static ssize_t lcd_store_contrast(struct device *dev,
655bfd7a RP	136	struct device_attribute attr, const char buf, size_t count)
1da177e4	137	{
68673afd	138	int rc = -ENXIO;
1da177e4	139	char *endp;
655bfd7a	140	struct lcd_device *ld = to_lcd_device(dev);
68673afd RP	141	int contrast = simple_strtoul(buf, &endp, 0);
68673afd RP	142	size_t size = endp - buf;
1da177e4	143
e7d2860b	144	if (isspace(*endp))
68673afd RP	145	size++;
68673afd RP	146	if (size != count)
1da177e4 LT	147	return -EINVAL;
1da177e4 LT	148
599a52d1 RP	149	mutex_lock(&ld->ops_lock);
599a52d1 RP	150	if (ld->ops && ld->ops->set_contrast) {
1da177e4	151	pr_debug("lcd: set contrast to %d\n", contrast);
599a52d1	152	ld->ops->set_contrast(ld, contrast);
1da177e4	153	rc = count;
68673afd	154	}
599a52d1	155	mutex_unlock(&ld->ops_lock);
1da177e4 LT	156
	157	return rc;
	158	}
	159
655bfd7a RP	160	static ssize_t lcd_show_max_contrast(struct device *dev,
655bfd7a RP	161	struct device_attribute attr, char buf)
1da177e4	162	{
655bfd7a	163	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	164
599a52d1	165	return sprintf(buf, "%d\n", ld->props.max_contrast);
1da177e4 LT	166	}
1da177e4 LT	167
0ad90efd	168	static struct class *lcd_class;
655bfd7a RP	169
655bfd7a RP	170	static void lcd_device_release(struct device *dev)
1da177e4 LT	171	{
	172	struct lcd_device *ld = to_lcd_device(dev);
	173	kfree(ld);
	174	}
	175
655bfd7a RP	176	static struct device_attribute lcd_device_attributes[] = {
	177	__ATTR(lcd_power, 0644, lcd_show_power, lcd_store_power),
	178	__ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	179	__ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
	180	__ATTR_NULL,
1da177e4 LT	181	};
1da177e4 LT	182
1da177e4 LT	183	/**
	184	* lcd_device_register - register a new object of lcd_device class.
	185	* @name: the name of the new object(must be the same as the name of the
	186	* respective framebuffer device).
655bfd7a RP	187	* @devdata: an optional pointer to be stored in the device. The
655bfd7a RP	188	* methods may retrieve it by using lcd_get_data(ld).
599a52d1	189	* @ops: the lcd operations structure.
1da177e4	190	*
655bfd7a	191	* Creates and registers a new lcd device. Returns either an ERR_PTR()
1da177e4 LT	192	* or a pointer to the newly allocated device.
1da177e4 LT	193	*/
655bfd7a RP	194	struct lcd_device lcd_device_register(const char name, struct device *parent,
655bfd7a RP	195	void devdata, struct lcd_ops ops)
1da177e4	196	{
1da177e4	197	struct lcd_device *new_ld;
655bfd7a	198	int rc;
1da177e4 LT	199
	200	pr_debug("lcd_device_register: name=%s\n", name);
	201
599a52d1	202	new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
90968e8e	203	if (!new_ld)
10ad1b73	204	return ERR_PTR(-ENOMEM);
1da177e4	205
599a52d1	206	mutex_init(&new_ld->ops_lock);
28ee086d	207	mutex_init(&new_ld->update_lock);
1da177e4	208
655bfd7a RP	209	new_ld->dev.class = lcd_class;
	210	new_ld->dev.parent = parent;
	211	new_ld->dev.release = lcd_device_release;
64dba9a9	212	dev_set_name(&new_ld->dev, name);
655bfd7a RP	213	dev_set_drvdata(&new_ld->dev, devdata);
	214
	215	rc = device_register(&new_ld->dev);
90968e8e	216	if (rc) {
2fd5a154	217	kfree(new_ld);
1da177e4 LT	218	return ERR_PTR(rc);
	219	}
	220
3d5eeadd	221	rc = lcd_register_fb(new_ld);
2fd5a154	222	if (rc) {
655bfd7a	223	device_unregister(&new_ld->dev);
2fd5a154 DT	224	return ERR_PTR(rc);
2fd5a154 DT	225	}
1da177e4	226
655bfd7a	227	new_ld->ops = ops;
1da177e4 LT	228
	229	return new_ld;
	230	}
	231	EXPORT_SYMBOL(lcd_device_register);
	232
	233	/**
	234	* lcd_device_unregister - unregisters a object of lcd_device class.
	235	* @ld: the lcd device object to be unregistered and freed.
	236	*
	237	* Unregisters a previously registered via lcd_device_register object.
	238	*/
	239	void lcd_device_unregister(struct lcd_device *ld)
	240	{
1da177e4 LT	241	if (!ld)
	242	return;
	243
599a52d1 RP	244	mutex_lock(&ld->ops_lock);
	245	ld->ops = NULL;
	246	mutex_unlock(&ld->ops_lock);
3d5eeadd	247	lcd_unregister_fb(ld);
655bfd7a RP	248
655bfd7a RP	249	device_unregister(&ld->dev);
1da177e4 LT	250	}
	251	EXPORT_SYMBOL(lcd_device_unregister);
	252
	253	static void __exit lcd_class_exit(void)
	254	{
655bfd7a	255	class_destroy(lcd_class);
1da177e4 LT	256	}
	257
	258	static int __init lcd_class_init(void)
	259	{
655bfd7a RP	260	lcd_class = class_create(THIS_MODULE, "lcd");
	261	if (IS_ERR(lcd_class)) {
	262	printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
	263	PTR_ERR(lcd_class));
	264	return PTR_ERR(lcd_class);
	265	}
	266
	267	lcd_class->dev_attrs = lcd_device_attributes;
	268	return 0;
1da177e4 LT	269	}
	270
	271	/*
	272	* if this is compiled into the kernel, we need to ensure that the
	273	* class is registered before users of the class try to register lcd's
	274	*/
	275	postcore_initcall(lcd_class_init);
	276	module_exit(lcd_class_exit);
	277
	278	MODULE_LICENSE("GPL");
	279	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	280	MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");