[mirror_ubuntu-focal-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>
#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("lcd: 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("lcd: 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)) {
		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:
d54ad83f ID	35	case FB_EARLY_EVENT_BLANK:
d54ad83f ID	36	case FB_R_EARLY_EVENT_BLANK:
faa312da EM	37	break;
faa312da EM	38	default:
3d5eeadd	39	return 0;
faa312da	40	}
3d5eeadd JS	41
3d5eeadd JS	42	ld = container_of(self, struct lcd_device, fb_notif);
faa312da EM	43	if (!ld->ops)
	44	return 0;
	45
599a52d1	46	mutex_lock(&ld->ops_lock);
faa312da	47	if (!ld->ops->check_fb \|\| ld->ops->check_fb(ld, evdata->info)) {
b3b4dc88 BD	48	if (event == FB_EVENT_BLANK) {
	49	if (ld->ops->set_power)
	50	ld->ops->set_power(ld, (int )evdata->data);
d54ad83f ID	51	} else if (event == FB_EARLY_EVENT_BLANK) {
	52	if (ld->ops->early_set_power)
	53	ld->ops->early_set_power(ld,
	54	(int )evdata->data);
	55	} else if (event == FB_R_EARLY_EVENT_BLANK) {
	56	if (ld->ops->r_early_set_power)
	57	ld->ops->r_early_set_power(ld,
	58	(int )evdata->data);
b3b4dc88 BD	59	} else {
	60	if (ld->ops->set_mode)
	61	ld->ops->set_mode(ld, evdata->data);
	62	}
faa312da	63	}
599a52d1	64	mutex_unlock(&ld->ops_lock);
3d5eeadd JS	65	return 0;
	66	}
	67
	68	static int lcd_register_fb(struct lcd_device *ld)
	69	{
1e0fa6bd	70	memset(&ld->fb_notif, 0, sizeof(ld->fb_notif));
3d5eeadd JS	71	ld->fb_notif.notifier_call = fb_notifier_callback;
	72	return fb_register_client(&ld->fb_notif);
	73	}
	74
	75	static void lcd_unregister_fb(struct lcd_device *ld)
	76	{
	77	fb_unregister_client(&ld->fb_notif);
	78	}
	79	#else
	80	static int lcd_register_fb(struct lcd_device *ld)
	81	{
	82	return 0;
	83	}
	84
	85	static inline void lcd_unregister_fb(struct lcd_device *ld)
	86	{
	87	}
	88	#endif /* CONFIG_FB */
	89
655bfd7a RP	90	static ssize_t lcd_show_power(struct device dev, struct device_attribute attr,
655bfd7a RP	91	char *buf)
1da177e4 LT	92	{
1da177e4 LT	93	int rc;
655bfd7a	94	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	95
599a52d1 RP	96	mutex_lock(&ld->ops_lock);
	97	if (ld->ops && ld->ops->get_power)
	98	rc = sprintf(buf, "%d\n", ld->ops->get_power(ld));
1da177e4 LT	99	else
1da177e4 LT	100	rc = -ENXIO;
599a52d1	101	mutex_unlock(&ld->ops_lock);
1da177e4 LT	102
	103	return rc;
	104	}
	105
655bfd7a RP	106	static ssize_t lcd_store_power(struct device *dev,
655bfd7a RP	107	struct device_attribute attr, const char buf, size_t count)
1da177e4	108	{
68673afd	109	int rc = -ENXIO;
655bfd7a	110	struct lcd_device *ld = to_lcd_device(dev);
66655760	111	unsigned long power;
1da177e4	112
66655760 JH	113	rc = kstrtoul(buf, 0, &power);
	114	if (rc)
	115	return rc;
1da177e4	116
599a52d1 RP	117	mutex_lock(&ld->ops_lock);
599a52d1 RP	118	if (ld->ops && ld->ops->set_power) {
66655760	119	pr_debug("lcd: set power to %lu\n", power);
599a52d1	120	ld->ops->set_power(ld, power);
1da177e4	121	rc = count;
68673afd	122	}
599a52d1	123	mutex_unlock(&ld->ops_lock);
1da177e4 LT	124
	125	return rc;
	126	}
	127
655bfd7a RP	128	static ssize_t lcd_show_contrast(struct device *dev,
655bfd7a RP	129	struct device_attribute attr, char buf)
1da177e4	130	{
68673afd	131	int rc = -ENXIO;
655bfd7a	132	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	133
599a52d1 RP	134	mutex_lock(&ld->ops_lock);
	135	if (ld->ops && ld->ops->get_contrast)
	136	rc = sprintf(buf, "%d\n", ld->ops->get_contrast(ld));
	137	mutex_unlock(&ld->ops_lock);
1da177e4 LT	138
	139	return rc;
	140	}
	141
655bfd7a RP	142	static ssize_t lcd_store_contrast(struct device *dev,
655bfd7a RP	143	struct device_attribute attr, const char buf, size_t count)
1da177e4	144	{
68673afd	145	int rc = -ENXIO;
655bfd7a	146	struct lcd_device *ld = to_lcd_device(dev);
66655760	147	unsigned long contrast;
1da177e4	148
66655760 JH	149	rc = kstrtoul(buf, 0, &contrast);
	150	if (rc)
	151	return rc;
1da177e4	152
599a52d1 RP	153	mutex_lock(&ld->ops_lock);
599a52d1 RP	154	if (ld->ops && ld->ops->set_contrast) {
66655760	155	pr_debug("lcd: set contrast to %lu\n", contrast);
599a52d1	156	ld->ops->set_contrast(ld, contrast);
1da177e4	157	rc = count;
68673afd	158	}
599a52d1	159	mutex_unlock(&ld->ops_lock);
1da177e4 LT	160
	161	return rc;
	162	}
	163
655bfd7a RP	164	static ssize_t lcd_show_max_contrast(struct device *dev,
655bfd7a RP	165	struct device_attribute attr, char buf)
1da177e4	166	{
655bfd7a	167	struct lcd_device *ld = to_lcd_device(dev);
1da177e4	168
599a52d1	169	return sprintf(buf, "%d\n", ld->props.max_contrast);
1da177e4 LT	170	}
1da177e4 LT	171
0ad90efd	172	static struct class *lcd_class;
655bfd7a RP	173
655bfd7a RP	174	static void lcd_device_release(struct device *dev)
1da177e4 LT	175	{
	176	struct lcd_device *ld = to_lcd_device(dev);
	177	kfree(ld);
	178	}
	179
655bfd7a RP	180	static struct device_attribute lcd_device_attributes[] = {
	181	__ATTR(lcd_power, 0644, lcd_show_power, lcd_store_power),
	182	__ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	183	__ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
	184	__ATTR_NULL,
1da177e4 LT	185	};
1da177e4 LT	186
1da177e4 LT	187	/**
	188	* lcd_device_register - register a new object of lcd_device class.
	189	* @name: the name of the new object(must be the same as the name of the
	190	* respective framebuffer device).
655bfd7a RP	191	* @devdata: an optional pointer to be stored in the device. The
655bfd7a RP	192	* methods may retrieve it by using lcd_get_data(ld).
599a52d1	193	* @ops: the lcd operations structure.
1da177e4	194	*
655bfd7a	195	* Creates and registers a new lcd device. Returns either an ERR_PTR()
1da177e4 LT	196	* or a pointer to the newly allocated device.
1da177e4 LT	197	*/
655bfd7a RP	198	struct lcd_device lcd_device_register(const char name, struct device *parent,
655bfd7a RP	199	void devdata, struct lcd_ops ops)
1da177e4	200	{
1da177e4	201	struct lcd_device *new_ld;
655bfd7a	202	int rc;
1da177e4 LT	203
	204	pr_debug("lcd_device_register: name=%s\n", name);
	205
599a52d1	206	new_ld = kzalloc(sizeof(struct lcd_device), GFP_KERNEL);
90968e8e	207	if (!new_ld)
10ad1b73	208	return ERR_PTR(-ENOMEM);
1da177e4	209
599a52d1	210	mutex_init(&new_ld->ops_lock);
28ee086d	211	mutex_init(&new_ld->update_lock);
1da177e4	212
655bfd7a RP	213	new_ld->dev.class = lcd_class;
	214	new_ld->dev.parent = parent;
	215	new_ld->dev.release = lcd_device_release;
64dba9a9	216	dev_set_name(&new_ld->dev, name);
655bfd7a RP	217	dev_set_drvdata(&new_ld->dev, devdata);
	218
	219	rc = device_register(&new_ld->dev);
90968e8e	220	if (rc) {
2fd5a154	221	kfree(new_ld);
1da177e4 LT	222	return ERR_PTR(rc);
	223	}
	224
3d5eeadd	225	rc = lcd_register_fb(new_ld);
2fd5a154	226	if (rc) {
655bfd7a	227	device_unregister(&new_ld->dev);
2fd5a154 DT	228	return ERR_PTR(rc);
2fd5a154 DT	229	}
1da177e4	230
655bfd7a	231	new_ld->ops = ops;
1da177e4 LT	232
	233	return new_ld;
	234	}
	235	EXPORT_SYMBOL(lcd_device_register);
	236
	237	/**
	238	* lcd_device_unregister - unregisters a object of lcd_device class.
	239	* @ld: the lcd device object to be unregistered and freed.
	240	*
	241	* Unregisters a previously registered via lcd_device_register object.
	242	*/
	243	void lcd_device_unregister(struct lcd_device *ld)
	244	{
1da177e4 LT	245	if (!ld)
	246	return;
	247
599a52d1 RP	248	mutex_lock(&ld->ops_lock);
	249	ld->ops = NULL;
	250	mutex_unlock(&ld->ops_lock);
3d5eeadd	251	lcd_unregister_fb(ld);
655bfd7a RP	252
655bfd7a RP	253	device_unregister(&ld->dev);
1da177e4 LT	254	}
	255	EXPORT_SYMBOL(lcd_device_unregister);
	256
	257	static void __exit lcd_class_exit(void)
	258	{
655bfd7a	259	class_destroy(lcd_class);
1da177e4 LT	260	}
	261
	262	static int __init lcd_class_init(void)
	263	{
655bfd7a RP	264	lcd_class = class_create(THIS_MODULE, "lcd");
	265	if (IS_ERR(lcd_class)) {
	266	printk(KERN_WARNING "Unable to create backlight class; errno = %ld\n",
	267	PTR_ERR(lcd_class));
	268	return PTR_ERR(lcd_class);
	269	}
	270
	271	lcd_class->dev_attrs = lcd_device_attributes;
	272	return 0;
1da177e4 LT	273	}
	274
	275	/*
	276	* if this is compiled into the kernel, we need to ensure that the
	277	* class is registered before users of the class try to register lcd's
	278	*/
	279	postcore_initcall(lcd_class_init);
	280	module_exit(lcd_class_exit);
	281
	282	MODULE_LICENSE("GPL");
	283	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
	284	MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");