[mirror_ubuntu-bionic-kernel.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;

	if (!lock_fb_info(evdata->info))
		return -ENODEV;
	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);
	unlock_fb_info(evdata->info);
	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;
	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>
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
66c1ca01 AR	43	if (!lock_fb_info(evdata->info))
66c1ca01 AR	44	return -ENODEV;
599a52d1	45	mutex_lock(&ld->ops_lock);
faa312da	46	if (!ld->ops->check_fb \|\| ld->ops->check_fb(ld, evdata->info)) {
b3b4dc88 BD	47	if (event == FB_EVENT_BLANK) {
	48	if (ld->ops->set_power)
	49	ld->ops->set_power(ld, (int )evdata->data);
	50	} else {
	51	if (ld->ops->set_mode)
	52	ld->ops->set_mode(ld, evdata->data);
	53	}
faa312da	54	}
599a52d1	55	mutex_unlock(&ld->ops_lock);
66c1ca01	56	unlock_fb_info(evdata->info);
3d5eeadd JS	57	return 0;
	58	}
	59
	60	static int lcd_register_fb(struct lcd_device *ld)
	61	{
	62	memset(&ld->fb_notif, 0, sizeof(&ld->fb_notif));
	63	ld->fb_notif.notifier_call = fb_notifier_callback;
	64	return fb_register_client(&ld->fb_notif);
	65	}
	66
	67	static void lcd_unregister_fb(struct lcd_device *ld)
	68	{
	69	fb_unregister_client(&ld->fb_notif);
	70	}
	71	#else
	72	static int lcd_register_fb(struct lcd_device *ld)
	73	{
	74	return 0;
	75	}
	76
	77	static inline void lcd_unregister_fb(struct lcd_device *ld)
	78	{
	79	}
	80	#endif /* CONFIG_FB */
	81
655bfd7a RP	82	static ssize_t lcd_show_power(struct device dev, struct device_attribute attr,
655bfd7a RP	83	char *buf)
1da177e4 LT	84	{
1da177e4 LT	85	int rc;
655bfd7a	86	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	87
599a52d1 RP	88	mutex_lock(&ld->ops_lock);
	89	if (ld->ops && ld->ops->get_power)
	90	rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
1da177e4 LT	91	else
1da177e4 LT	92	rc = -ENXIO;
599a52d1	93	mutex_unlock(&ld->ops_lock);
1da177e4 LT	94
	95	return rc;
	96	}
	97
655bfd7a RP	98	static ssize_t lcd_store_power(struct device *dev,
655bfd7a RP	99	struct device_attribute attr, const char buf, size_t count)
1da177e4	100	{
68673afd	101	int rc = -ENXIO;
1da177e4	102	char *endp;
655bfd7a	103	struct lcd_device *ld = to_lcd_device(dev);
68673afd RP	104	int power = simple_strtoul(buf, &endp, 0);
68673afd RP	105	size_t size = endp - buf;
1da177e4	106
68673afd RP	107	if (endp && isspace(endp))
	108	size++;
	109	if (size != count)
1da177e4 LT	110	return -EINVAL;
1da177e4 LT	111
599a52d1 RP	112	mutex_lock(&ld->ops_lock);
599a52d1 RP	113	if (ld->ops && ld->ops->set_power) {
1da177e4	114	pr_debug("lcd: set power to %d\n", power);
599a52d1	115	ld->ops->set_power(ld, power);
1da177e4	116	rc = count;
68673afd	117	}
599a52d1	118	mutex_unlock(&ld->ops_lock);
1da177e4 LT	119
	120	return rc;
	121	}
	122
655bfd7a RP	123	static ssize_t lcd_show_contrast(struct device *dev,
655bfd7a RP	124	struct device_attribute attr, char buf)
1da177e4	125	{
68673afd	126	int rc = -ENXIO;
655bfd7a	127	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	128
599a52d1 RP	129	mutex_lock(&ld->ops_lock);
	130	if (ld->ops && ld->ops->get_contrast)
	131	rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
	132	mutex_unlock(&ld->ops_lock);
1da177e4 LT	133
	134	return rc;
	135	}
	136
655bfd7a RP	137	static ssize_t lcd_store_contrast(struct device *dev,
655bfd7a RP	138	struct device_attribute attr, const char buf, size_t count)
1da177e4	139	{
68673afd	140	int rc = -ENXIO;
1da177e4	141	char *endp;
655bfd7a	142	struct lcd_device *ld = to_lcd_device(dev);
68673afd RP	143	int contrast = simple_strtoul(buf, &endp, 0);
68673afd RP	144	size_t size = endp - buf;
1da177e4	145
68673afd RP	146	if (endp && isspace(endp))
	147	size++;
	148	if (size != count)
1da177e4 LT	149	return -EINVAL;
1da177e4 LT	150
599a52d1 RP	151	mutex_lock(&ld->ops_lock);
599a52d1 RP	152	if (ld->ops && ld->ops->set_contrast) {
1da177e4	153	pr_debug("lcd: set contrast to %d\n", contrast);
599a52d1	154	ld->ops->set_contrast(ld, contrast);
1da177e4	155	rc = count;
68673afd	156	}
599a52d1	157	mutex_unlock(&ld->ops_lock);
1da177e4 LT	158
	159	return rc;
	160	}
	161
655bfd7a RP	162	static ssize_t lcd_show_max_contrast(struct device *dev,
655bfd7a RP	163	struct device_attribute attr, char buf)
1da177e4	164	{
655bfd7a	165	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	166
599a52d1	167	return sprintf(buf, "%d\n", ld->props.max_contrast);
1da177e4 LT	168	}
1da177e4 LT	169
0ad90efd	170	static struct class *lcd_class;
655bfd7a RP	171
655bfd7a RP	172	static void lcd_device_release(struct device *dev)
1da177e4 LT	173	{
	174	struct lcd_device *ld = to_lcd_device(dev);
	175	kfree(ld);
	176	}
	177
655bfd7a RP	178	static struct device_attribute lcd_device_attributes[] = {
	179	__ATTR(lcd_power, 0644, lcd_show_power, lcd_store_power),
	180	__ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	181	__ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
	182	__ATTR_NULL,
1da177e4 LT	183	};
1da177e4 LT	184
1da177e4 LT	185	/**
	186	* lcd_device_register - register a new object of lcd_device class.
	187	* @name: the name of the new object(must be the same as the name of the
	188	* respective framebuffer device).
655bfd7a RP	189	* @devdata: an optional pointer to be stored in the device. The
655bfd7a RP	190	* methods may retrieve it by using lcd_get_data(ld).
599a52d1	191	* @ops: the lcd operations structure.
1da177e4	192	*
655bfd7a	193	* Creates and registers a new lcd device. Returns either an ERR_PTR()
1da177e4 LT	194	* or a pointer to the newly allocated device.
1da177e4 LT	195	*/
655bfd7a RP	196	struct lcd_device lcd_device_register(const char name, struct device *parent,
655bfd7a RP	197	void devdata, struct lcd_ops ops)
1da177e4	198	{
1da177e4	199	struct lcd_device *new_ld;
655bfd7a	200	int rc;
1da177e4 LT	201
	202	pr_debug("lcd_device_register: name=%s\n", name);
	203
599a52d1	204	new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
90968e8e	205	if (!new_ld)
10ad1b73	206	return ERR_PTR(-ENOMEM);
1da177e4	207
599a52d1	208	mutex_init(&new_ld->ops_lock);
28ee086d	209	mutex_init(&new_ld->update_lock);
1da177e4	210
655bfd7a RP	211	new_ld->dev.class = lcd_class;
	212	new_ld->dev.parent = parent;
	213	new_ld->dev.release = lcd_device_release;
64dba9a9	214	dev_set_name(&new_ld->dev, name);
655bfd7a RP	215	dev_set_drvdata(&new_ld->dev, devdata);
	216
	217	rc = device_register(&new_ld->dev);
90968e8e	218	if (rc) {
2fd5a154	219	kfree(new_ld);
1da177e4 LT	220	return ERR_PTR(rc);
	221	}
	222
3d5eeadd	223	rc = lcd_register_fb(new_ld);
2fd5a154	224	if (rc) {
655bfd7a	225	device_unregister(&new_ld->dev);
2fd5a154 DT	226	return ERR_PTR(rc);
2fd5a154 DT	227	}
1da177e4	228
655bfd7a	229	new_ld->ops = ops;
1da177e4 LT	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	{
1da177e4 LT	243	if (!ld)
	244	return;
	245
599a52d1 RP	246	mutex_lock(&ld->ops_lock);
	247	ld->ops = NULL;
	248	mutex_unlock(&ld->ops_lock);
3d5eeadd	249	lcd_unregister_fb(ld);
655bfd7a RP	250
655bfd7a RP	251	device_unregister(&ld->dev);
1da177e4 LT	252	}
	253	EXPORT_SYMBOL(lcd_device_unregister);
	254
	255	static void __exit lcd_class_exit(void)
	256	{
655bfd7a	257	class_destroy(lcd_class);
1da177e4 LT	258	}
	259
	260	static int __init lcd_class_init(void)
	261	{
655bfd7a RP	262	lcd_class = class_create(THIS_MODULE, "lcd");
	263	if (IS_ERR(lcd_class)) {
	264	printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
	265	PTR_ERR(lcd_class));
	266	return PTR_ERR(lcd_class);
	267	}
	268
	269	lcd_class->dev_attrs = lcd_device_attributes;
	270	return 0;
1da177e4 LT	271	}
	272
	273	/*
	274	* if this is compiled into the kernel, we need to ensure that the
	275	* class is registered before users of the class try to register lcd's
	276	*/
	277	postcore_initcall(lcd_class_init);
	278	module_exit(lcd_class_exit);
	279
	280	MODULE_LICENSE("GPL");
	281	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	282	MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");