[deliverable/linux.git] / drivers / video / backlight / lcd.c

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

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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:
	case FB_EARLY_EVENT_BLANK:
	case FB_R_EARLY_EVENT_BLANK:
		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 (event == FB_EARLY_EVENT_BLANK) {
			if (ld->ops->early_set_power)
				ld->ops->early_set_power(ld,
						*(int *)evdata->data);
		} else if (event == FB_R_EARLY_EVENT_BLANK) {
			if (ld->ops->r_early_set_power)
				ld->ops->r_early_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;
	struct lcd_device *ld = to_lcd_device(dev);
	unsigned long power;

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

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->set_power) {
		pr_debug("set power to %lu\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;
	struct lcd_device *ld = to_lcd_device(dev);
	unsigned long contrast;

	rc = kstrtoul(buf, 0, &contrast);
	if (rc)
		return rc;

	mutex_lock(&ld->ops_lock);
	if (ld->ops && ld->ops->set_contrast) {
		pr_debug("set contrast to %lu\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)) {
		pr_warn("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
35f96162 JH	8	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35f96162 JH	9
1da177e4 LT	10	#include <linux/module.h>
	11	#include <linux/init.h>
	12	#include <linux/device.h>
	13	#include <linux/lcd.h>
	14	#include <linux/notifier.h>
	15	#include <linux/ctype.h>
	16	#include <linux/err.h>
	17	#include <linux/fb.h>
5a0e3ad6	18	#include <linux/slab.h>
1da177e4	19
3d5eeadd JS	20	#if defined(CONFIG_FB) \|\| (defined(CONFIG_FB_MODULE) && \
	21	defined(CONFIG_LCD_CLASS_DEVICE_MODULE))
	22	/* This callback gets called when something important happens inside a
	23	* framebuffer driver. We're looking if that important event is blanking,
	24	* and if it is, we're switching lcd power as well ...
	25	*/
	26	static int fb_notifier_callback(struct notifier_block *self,
	27	unsigned long event, void *data)
	28	{
	29	struct lcd_device *ld;
	30	struct fb_event *evdata = data;
	31
	32	/* If we aren't interested in this event, skip it immediately ... */
faa312da EM	33	switch (event) {
	34	case FB_EVENT_BLANK:
	35	case FB_EVENT_MODE_CHANGE:
	36	case FB_EVENT_MODE_CHANGE_ALL:
d54ad83f ID	37	case FB_EARLY_EVENT_BLANK:
d54ad83f ID	38	case FB_R_EARLY_EVENT_BLANK:
faa312da EM	39	break;
faa312da EM	40	default:
3d5eeadd	41	return 0;
faa312da	42	}
3d5eeadd JS	43
3d5eeadd JS	44	ld = container_of(self, struct lcd_device, fb_notif);
faa312da EM	45	if (!ld->ops)
	46	return 0;
	47
599a52d1	48	mutex_lock(&ld->ops_lock);
faa312da	49	if (!ld->ops->check_fb \|\| ld->ops->check_fb(ld, evdata->info)) {
b3b4dc88 BD	50	if (event == FB_EVENT_BLANK) {
	51	if (ld->ops->set_power)
	52	ld->ops->set_power(ld, (int )evdata->data);
d54ad83f ID	53	} else if (event == FB_EARLY_EVENT_BLANK) {
	54	if (ld->ops->early_set_power)
	55	ld->ops->early_set_power(ld,
	56	(int )evdata->data);
	57	} else if (event == FB_R_EARLY_EVENT_BLANK) {
	58	if (ld->ops->r_early_set_power)
	59	ld->ops->r_early_set_power(ld,
	60	(int )evdata->data);
b3b4dc88 BD	61	} else {
	62	if (ld->ops->set_mode)
	63	ld->ops->set_mode(ld, evdata->data);
	64	}
faa312da	65	}
599a52d1	66	mutex_unlock(&ld->ops_lock);
3d5eeadd JS	67	return 0;
	68	}
	69
	70	static int lcd_register_fb(struct lcd_device *ld)
	71	{
1e0fa6bd	72	memset(&ld->fb_notif, 0, sizeof(ld->fb_notif));
3d5eeadd JS	73	ld->fb_notif.notifier_call = fb_notifier_callback;
	74	return fb_register_client(&ld->fb_notif);
	75	}
	76
	77	static void lcd_unregister_fb(struct lcd_device *ld)
	78	{
	79	fb_unregister_client(&ld->fb_notif);
	80	}
	81	#else
	82	static int lcd_register_fb(struct lcd_device *ld)
	83	{
	84	return 0;
	85	}
	86
	87	static inline void lcd_unregister_fb(struct lcd_device *ld)
	88	{
	89	}
	90	#endif /* CONFIG_FB */
	91
655bfd7a RP	92	static ssize_t lcd_show_power(struct device dev, struct device_attribute attr,
655bfd7a RP	93	char *buf)
1da177e4 LT	94	{
1da177e4 LT	95	int rc;
655bfd7a	96	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	97
599a52d1 RP	98	mutex_lock(&ld->ops_lock);
	99	if (ld->ops && ld->ops->get_power)
	100	rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
1da177e4 LT	101	else
1da177e4 LT	102	rc = -ENXIO;
599a52d1	103	mutex_unlock(&ld->ops_lock);
1da177e4 LT	104
	105	return rc;
	106	}
	107
655bfd7a RP	108	static ssize_t lcd_store_power(struct device *dev,
655bfd7a RP	109	struct device_attribute attr, const char buf, size_t count)
1da177e4	110	{
68673afd	111	int rc = -ENXIO;
655bfd7a	112	struct lcd_device *ld = to_lcd_device(dev);
66655760	113	unsigned long power;
1da177e4	114
66655760 JH	115	rc = kstrtoul(buf, 0, &power);
	116	if (rc)
	117	return rc;
1da177e4	118
599a52d1 RP	119	mutex_lock(&ld->ops_lock);
599a52d1 RP	120	if (ld->ops && ld->ops->set_power) {
35f96162	121	pr_debug("set power to %lu\n", power);
599a52d1	122	ld->ops->set_power(ld, power);
1da177e4	123	rc = count;
68673afd	124	}
599a52d1	125	mutex_unlock(&ld->ops_lock);
1da177e4 LT	126
	127	return rc;
	128	}
	129
655bfd7a RP	130	static ssize_t lcd_show_contrast(struct device *dev,
655bfd7a RP	131	struct device_attribute attr, char buf)
1da177e4	132	{
68673afd	133	int rc = -ENXIO;
655bfd7a	134	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	135
599a52d1 RP	136	mutex_lock(&ld->ops_lock);
	137	if (ld->ops && ld->ops->get_contrast)
	138	rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
	139	mutex_unlock(&ld->ops_lock);
1da177e4 LT	140
	141	return rc;
	142	}
	143
655bfd7a RP	144	static ssize_t lcd_store_contrast(struct device *dev,
655bfd7a RP	145	struct device_attribute attr, const char buf, size_t count)
1da177e4	146	{
68673afd	147	int rc = -ENXIO;
655bfd7a	148	struct lcd_device *ld = to_lcd_device(dev);
66655760	149	unsigned long contrast;
1da177e4	150
66655760 JH	151	rc = kstrtoul(buf, 0, &contrast);
	152	if (rc)
	153	return rc;
1da177e4	154
599a52d1 RP	155	mutex_lock(&ld->ops_lock);
599a52d1 RP	156	if (ld->ops && ld->ops->set_contrast) {
35f96162	157	pr_debug("set contrast to %lu\n", contrast);
599a52d1	158	ld->ops->set_contrast(ld, contrast);
1da177e4	159	rc = count;
68673afd	160	}
599a52d1	161	mutex_unlock(&ld->ops_lock);
1da177e4 LT	162
	163	return rc;
	164	}
	165
655bfd7a RP	166	static ssize_t lcd_show_max_contrast(struct device *dev,
655bfd7a RP	167	struct device_attribute attr, char buf)
1da177e4	168	{
655bfd7a	169	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	170
599a52d1	171	return sprintf(buf, "%d\n", ld->props.max_contrast);
1da177e4 LT	172	}
1da177e4 LT	173
0ad90efd	174	static struct class *lcd_class;
655bfd7a RP	175
655bfd7a RP	176	static void lcd_device_release(struct device *dev)
1da177e4 LT	177	{
	178	struct lcd_device *ld = to_lcd_device(dev);
	179	kfree(ld);
	180	}
	181
655bfd7a RP	182	static struct device_attribute lcd_device_attributes[] = {
	183	__ATTR(lcd_power, 0644, lcd_show_power, lcd_store_power),
	184	__ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	185	__ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
	186	__ATTR_NULL,
1da177e4 LT	187	};
1da177e4 LT	188
1da177e4 LT	189	/**
	190	* lcd_device_register - register a new object of lcd_device class.
	191	* @name: the name of the new object(must be the same as the name of the
	192	* respective framebuffer device).
655bfd7a RP	193	* @devdata: an optional pointer to be stored in the device. The
655bfd7a RP	194	* methods may retrieve it by using lcd_get_data(ld).
599a52d1	195	* @ops: the lcd operations structure.
1da177e4	196	*
655bfd7a	197	* Creates and registers a new lcd device. Returns either an ERR_PTR()
1da177e4 LT	198	* or a pointer to the newly allocated device.
1da177e4 LT	199	*/
655bfd7a RP	200	struct lcd_device lcd_device_register(const char name, struct device *parent,
655bfd7a RP	201	void devdata, struct lcd_ops ops)
1da177e4	202	{
1da177e4	203	struct lcd_device *new_ld;
655bfd7a	204	int rc;
1da177e4 LT	205
	206	pr_debug("lcd_device_register: name=%s\n", name);
	207
599a52d1	208	new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
90968e8e	209	if (!new_ld)
10ad1b73	210	return ERR_PTR(-ENOMEM);
1da177e4	211
599a52d1	212	mutex_init(&new_ld->ops_lock);
28ee086d	213	mutex_init(&new_ld->update_lock);
1da177e4	214
655bfd7a RP	215	new_ld->dev.class = lcd_class;
	216	new_ld->dev.parent = parent;
	217	new_ld->dev.release = lcd_device_release;
64dba9a9	218	dev_set_name(&new_ld->dev, name);
655bfd7a RP	219	dev_set_drvdata(&new_ld->dev, devdata);
	220
	221	rc = device_register(&new_ld->dev);
90968e8e	222	if (rc) {
2fd5a154	223	kfree(new_ld);
1da177e4 LT	224	return ERR_PTR(rc);
	225	}
	226
3d5eeadd	227	rc = lcd_register_fb(new_ld);
2fd5a154	228	if (rc) {
655bfd7a	229	device_unregister(&new_ld->dev);
2fd5a154 DT	230	return ERR_PTR(rc);
2fd5a154 DT	231	}
1da177e4	232
655bfd7a	233	new_ld->ops = ops;
1da177e4 LT	234
	235	return new_ld;
	236	}
	237	EXPORT_SYMBOL(lcd_device_register);
	238
	239	/**
	240	* lcd_device_unregister - unregisters a object of lcd_device class.
	241	* @ld: the lcd device object to be unregistered and freed.
	242	*
	243	* Unregisters a previously registered via lcd_device_register object.
	244	*/
	245	void lcd_device_unregister(struct lcd_device *ld)
	246	{
1da177e4 LT	247	if (!ld)
	248	return;
	249
599a52d1 RP	250	mutex_lock(&ld->ops_lock);
	251	ld->ops = NULL;
	252	mutex_unlock(&ld->ops_lock);
3d5eeadd	253	lcd_unregister_fb(ld);
655bfd7a RP	254
655bfd7a RP	255	device_unregister(&ld->dev);
1da177e4 LT	256	}
	257	EXPORT_SYMBOL(lcd_device_unregister);
	258
	259	static void __exit lcd_class_exit(void)
	260	{
655bfd7a	261	class_destroy(lcd_class);
1da177e4 LT	262	}
	263
	264	static int __init lcd_class_init(void)
	265	{
655bfd7a RP	266	lcd_class = class_create(THIS_MODULE, "lcd");
655bfd7a RP	267	if (IS_ERR(lcd_class)) {
35f96162 JH	268	pr_warn("Unable to create backlight class; errno = %ld\n",
35f96162 JH	269	PTR_ERR(lcd_class));
655bfd7a RP	270	return PTR_ERR(lcd_class);
	271	}
	272
	273	lcd_class->dev_attrs = lcd_device_attributes;
	274	return 0;
1da177e4 LT	275	}
	276
	277	/*
	278	* if this is compiled into the kernel, we need to ensure that the
	279	* class is registered before users of the class try to register lcd's
	280	*/
	281	postcore_initcall(lcd_class_init);
	282	module_exit(lcd_class_exit);
	283
	284	MODULE_LICENSE("GPL");
	285	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	286	MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");