[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 ... */
	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)
			ld->ops->set_power(ld, *(int *)evdata->data);
		else
			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 (*endp && 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 (*endp && 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;
	strlcpy(new_ld->dev.bus_id, name, BUS_ID_SIZE);
	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>
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 ... */
faa312da EM	30	switch (event) {
	31	case FB_EVENT_BLANK:
	32	case FB_EVENT_MODE_CHANGE:
	33	case FB_EVENT_MODE_CHANGE_ALL:
	34	break;
	35	default:
3d5eeadd	36	return 0;
faa312da	37	}
3d5eeadd JS	38
3d5eeadd JS	39	ld = container_of(self, struct lcd_device, fb_notif);
faa312da EM	40	if (!ld->ops)
	41	return 0;
	42
599a52d1	43	mutex_lock(&ld->ops_lock);
faa312da EM	44	if (!ld->ops->check_fb \|\| ld->ops->check_fb(ld, evdata->info)) {
faa312da EM	45	if (event == FB_EVENT_BLANK)
599a52d1	46	ld->ops->set_power(ld, (int )evdata->data);
faa312da EM	47	else
	48	ld->ops->set_mode(ld, evdata->data);
	49	}
599a52d1	50	mutex_unlock(&ld->ops_lock);
3d5eeadd JS	51	return 0;
	52	}
	53
	54	static int lcd_register_fb(struct lcd_device *ld)
	55	{
	56	memset(&ld->fb_notif, 0, sizeof(&ld->fb_notif));
	57	ld->fb_notif.notifier_call = fb_notifier_callback;
	58	return fb_register_client(&ld->fb_notif);
	59	}
	60
	61	static void lcd_unregister_fb(struct lcd_device *ld)
	62	{
	63	fb_unregister_client(&ld->fb_notif);
	64	}
	65	#else
	66	static int lcd_register_fb(struct lcd_device *ld)
	67	{
	68	return 0;
	69	}
	70
	71	static inline void lcd_unregister_fb(struct lcd_device *ld)
	72	{
	73	}
	74	#endif /* CONFIG_FB */
	75
655bfd7a RP	76	static ssize_t lcd_show_power(struct device dev, struct device_attribute attr,
655bfd7a RP	77	char *buf)
1da177e4 LT	78	{
1da177e4 LT	79	int rc;
655bfd7a	80	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	81
599a52d1 RP	82	mutex_lock(&ld->ops_lock);
	83	if (ld->ops && ld->ops->get_power)
	84	rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
1da177e4 LT	85	else
1da177e4 LT	86	rc = -ENXIO;
599a52d1	87	mutex_unlock(&ld->ops_lock);
1da177e4 LT	88
	89	return rc;
	90	}
	91
655bfd7a RP	92	static ssize_t lcd_store_power(struct device *dev,
655bfd7a RP	93	struct device_attribute attr, const char buf, size_t count)
1da177e4	94	{
68673afd	95	int rc = -ENXIO;
1da177e4	96	char *endp;
655bfd7a	97	struct lcd_device *ld = to_lcd_device(dev);
68673afd RP	98	int power = simple_strtoul(buf, &endp, 0);
68673afd RP	99	size_t size = endp - buf;
1da177e4	100
68673afd RP	101	if (endp && isspace(endp))
	102	size++;
	103	if (size != count)
1da177e4 LT	104	return -EINVAL;
1da177e4 LT	105
599a52d1 RP	106	mutex_lock(&ld->ops_lock);
599a52d1 RP	107	if (ld->ops && ld->ops->set_power) {
1da177e4	108	pr_debug("lcd: set power to %d\n", power);
599a52d1	109	ld->ops->set_power(ld, power);
1da177e4	110	rc = count;
68673afd	111	}
599a52d1	112	mutex_unlock(&ld->ops_lock);
1da177e4 LT	113
	114	return rc;
	115	}
	116
655bfd7a RP	117	static ssize_t lcd_show_contrast(struct device *dev,
655bfd7a RP	118	struct device_attribute attr, char buf)
1da177e4	119	{
68673afd	120	int rc = -ENXIO;
655bfd7a	121	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	122
599a52d1 RP	123	mutex_lock(&ld->ops_lock);
	124	if (ld->ops && ld->ops->get_contrast)
	125	rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
	126	mutex_unlock(&ld->ops_lock);
1da177e4 LT	127
	128	return rc;
	129	}
	130
655bfd7a RP	131	static ssize_t lcd_store_contrast(struct device *dev,
655bfd7a RP	132	struct device_attribute attr, const char buf, size_t count)
1da177e4	133	{
68673afd	134	int rc = -ENXIO;
1da177e4	135	char *endp;
655bfd7a	136	struct lcd_device *ld = to_lcd_device(dev);
68673afd RP	137	int contrast = simple_strtoul(buf, &endp, 0);
68673afd RP	138	size_t size = endp - buf;
1da177e4	139
68673afd RP	140	if (endp && isspace(endp))
	141	size++;
	142	if (size != count)
1da177e4 LT	143	return -EINVAL;
1da177e4 LT	144
599a52d1 RP	145	mutex_lock(&ld->ops_lock);
599a52d1 RP	146	if (ld->ops && ld->ops->set_contrast) {
1da177e4	147	pr_debug("lcd: set contrast to %d\n", contrast);
599a52d1	148	ld->ops->set_contrast(ld, contrast);
1da177e4	149	rc = count;
68673afd	150	}
599a52d1	151	mutex_unlock(&ld->ops_lock);
1da177e4 LT	152
	153	return rc;
	154	}
	155
655bfd7a RP	156	static ssize_t lcd_show_max_contrast(struct device *dev,
655bfd7a RP	157	struct device_attribute attr, char buf)
1da177e4	158	{
655bfd7a	159	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	160
599a52d1	161	return sprintf(buf, "%d\n", ld->props.max_contrast);
1da177e4 LT	162	}
1da177e4 LT	163
0ad90efd	164	static struct class *lcd_class;
655bfd7a RP	165
655bfd7a RP	166	static void lcd_device_release(struct device *dev)
1da177e4 LT	167	{
	168	struct lcd_device *ld = to_lcd_device(dev);
	169	kfree(ld);
	170	}
	171
655bfd7a RP	172	static struct device_attribute lcd_device_attributes[] = {
	173	__ATTR(lcd_power, 0644, lcd_show_power, lcd_store_power),
	174	__ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	175	__ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
	176	__ATTR_NULL,
1da177e4 LT	177	};
1da177e4 LT	178
1da177e4 LT	179	/**
	180	* lcd_device_register - register a new object of lcd_device class.
	181	* @name: the name of the new object(must be the same as the name of the
	182	* respective framebuffer device).
655bfd7a RP	183	* @devdata: an optional pointer to be stored in the device. The
655bfd7a RP	184	* methods may retrieve it by using lcd_get_data(ld).
599a52d1	185	* @ops: the lcd operations structure.
1da177e4	186	*
655bfd7a	187	* Creates and registers a new lcd device. Returns either an ERR_PTR()
1da177e4 LT	188	* or a pointer to the newly allocated device.
1da177e4 LT	189	*/
655bfd7a RP	190	struct lcd_device lcd_device_register(const char name, struct device *parent,
655bfd7a RP	191	void devdata, struct lcd_ops ops)
1da177e4	192	{
1da177e4	193	struct lcd_device *new_ld;
655bfd7a	194	int rc;
1da177e4 LT	195
	196	pr_debug("lcd_device_register: name=%s\n", name);
	197
599a52d1	198	new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
90968e8e	199	if (!new_ld)
10ad1b73	200	return ERR_PTR(-ENOMEM);
1da177e4	201
599a52d1	202	mutex_init(&new_ld->ops_lock);
28ee086d	203	mutex_init(&new_ld->update_lock);
1da177e4	204
655bfd7a RP	205	new_ld->dev.class = lcd_class;
	206	new_ld->dev.parent = parent;
	207	new_ld->dev.release = lcd_device_release;
	208	strlcpy(new_ld->dev.bus_id, name, BUS_ID_SIZE);
	209	dev_set_drvdata(&new_ld->dev, devdata);
	210
	211	rc = device_register(&new_ld->dev);
90968e8e	212	if (rc) {
2fd5a154	213	kfree(new_ld);
1da177e4 LT	214	return ERR_PTR(rc);
	215	}
	216
3d5eeadd	217	rc = lcd_register_fb(new_ld);
2fd5a154	218	if (rc) {
655bfd7a	219	device_unregister(&new_ld->dev);
2fd5a154 DT	220	return ERR_PTR(rc);
2fd5a154 DT	221	}
1da177e4	222
655bfd7a	223	new_ld->ops = ops;
1da177e4 LT	224
	225	return new_ld;
	226	}
	227	EXPORT_SYMBOL(lcd_device_register);
	228
	229	/**
	230	* lcd_device_unregister - unregisters a object of lcd_device class.
	231	* @ld: the lcd device object to be unregistered and freed.
	232	*
	233	* Unregisters a previously registered via lcd_device_register object.
	234	*/
	235	void lcd_device_unregister(struct lcd_device *ld)
	236	{
1da177e4 LT	237	if (!ld)
	238	return;
	239
599a52d1 RP	240	mutex_lock(&ld->ops_lock);
	241	ld->ops = NULL;
	242	mutex_unlock(&ld->ops_lock);
3d5eeadd	243	lcd_unregister_fb(ld);
655bfd7a RP	244
655bfd7a RP	245	device_unregister(&ld->dev);
1da177e4 LT	246	}
	247	EXPORT_SYMBOL(lcd_device_unregister);
	248
	249	static void __exit lcd_class_exit(void)
	250	{
655bfd7a	251	class_destroy(lcd_class);
1da177e4 LT	252	}
	253
	254	static int __init lcd_class_init(void)
	255	{
655bfd7a RP	256	lcd_class = class_create(THIS_MODULE, "lcd");
	257	if (IS_ERR(lcd_class)) {
	258	printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
	259	PTR_ERR(lcd_class));
	260	return PTR_ERR(lcd_class);
	261	}
	262
	263	lcd_class->dev_attrs = lcd_device_attributes;
	264	return 0;
1da177e4 LT	265	}
	266
	267	/*
	268	* if this is compiled into the kernel, we need to ensure that the
	269	* class is registered before users of the class try to register lcd's
	270	*/
	271	postcore_initcall(lcd_class_init);
	272	module_exit(lcd_class_exit);
	273
	274	MODULE_LICENSE("GPL");
	275	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	276	MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");