[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>

static ssize_t lcd_show_power(struct class_device *cdev, char *buf)
{
	int rc;
	struct lcd_device *ld = to_lcd_device(cdev);

	down(&ld->sem);
	if (likely(ld->props && ld->props->get_power))
		rc = sprintf(buf, "%d\n", ld->props->get_power(ld));
	else
		rc = -ENXIO;
	up(&ld->sem);

	return rc;
}

static ssize_t lcd_store_power(struct class_device *cdev, const char *buf, size_t count)
{
	int rc, power;
	char *endp;
	struct lcd_device *ld = to_lcd_device(cdev);

	power = simple_strtoul(buf, &endp, 0);
	if (*endp && !isspace(*endp))
		return -EINVAL;

	down(&ld->sem);
	if (likely(ld->props && ld->props->set_power)) {
		pr_debug("lcd: set power to %d\n", power);
		ld->props->set_power(ld, power);
		rc = count;
	} else
		rc = -ENXIO;
	up(&ld->sem);

	return rc;
}

static ssize_t lcd_show_contrast(struct class_device *cdev, char *buf)
{
	int rc;
	struct lcd_device *ld = to_lcd_device(cdev);

	down(&ld->sem);
	if (likely(ld->props && ld->props->get_contrast))
		rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld));
	else
		rc = -ENXIO;
	up(&ld->sem);

	return rc;
}

static ssize_t lcd_store_contrast(struct class_device *cdev, const char *buf, size_t count)
{
	int rc, contrast;
	char *endp;
	struct lcd_device *ld = to_lcd_device(cdev);

	contrast = simple_strtoul(buf, &endp, 0);
	if (*endp && !isspace(*endp))
		return -EINVAL;

	down(&ld->sem);
	if (likely(ld->props && ld->props->set_contrast)) {
		pr_debug("lcd: set contrast to %d\n", contrast);
		ld->props->set_contrast(ld, contrast);
		rc = count;
	} else
		rc = -ENXIO;
	up(&ld->sem);

	return rc;
}

static ssize_t lcd_show_max_contrast(struct class_device *cdev, char *buf)
{
	int rc;
	struct lcd_device *ld = to_lcd_device(cdev);

	down(&ld->sem);
	if (likely(ld->props))
		rc = sprintf(buf, "%d\n", ld->props->max_contrast);
	else
		rc = -ENXIO;
	up(&ld->sem);

	return rc;
}

static void lcd_class_release(struct class_device *dev)
{
	struct lcd_device *ld = to_lcd_device(dev);
	kfree(ld);
}

static struct class lcd_class = {
	.name = "lcd",
	.release = lcd_class_release,
};

#define DECLARE_ATTR(_name,_mode,_show,_store)			\
{							 	\
	.attr	= { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE },	\
	.show	= _show,					\
	.store	= _store,					\
}

static struct class_device_attribute lcd_class_device_attributes[] = {
	DECLARE_ATTR(power, 0644, lcd_show_power, lcd_store_power),
	DECLARE_ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
	DECLARE_ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
};

/* 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 =(struct fb_event *)data;

	/* If we aren't interested in this event, skip it immediately ... */
	if (event != FB_EVENT_BLANK)
		return 0;

	ld = container_of(self, struct lcd_device, fb_notif);
	down(&ld->sem);
	if (ld->props)
		if (!ld->props->check_fb || ld->props->check_fb(evdata->info))
			ld->props->set_power(ld, *(int *)evdata->data);
	up(&ld->sem);
	return 0;
}

/**
 * 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 class_device. The
 *   methods may retrieve it by using class_get_devdata(ld->class_dev).
 * @lp: the lcd properties structure.
 *
 * Creates and registers a new lcd class_device. Returns either an ERR_PTR()
 * or a pointer to the newly allocated device.
 */
struct lcd_device *lcd_device_register(const char *name, void *devdata,
				       struct lcd_properties *lp)
{
	int i, rc;
	struct lcd_device *new_ld;

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

	new_ld = kmalloc(sizeof(struct lcd_device), GFP_KERNEL);
	if (unlikely(!new_ld))
		return ERR_PTR(ENOMEM);

	init_MUTEX(&new_ld->sem);
	new_ld->props = lp;
	memset(&new_ld->class_dev, 0, sizeof(new_ld->class_dev));
	new_ld->class_dev.class = &lcd_class;
	strlcpy(new_ld->class_dev.class_id, name, KOBJ_NAME_LEN);
	class_set_devdata(&new_ld->class_dev, devdata);

	rc = class_device_register(&new_ld->class_dev);
	if (unlikely(rc)) {
error:		kfree(new_ld);
		return ERR_PTR(rc);
	}

	memset(&new_ld->fb_notif, 0, sizeof(new_ld->fb_notif));
	new_ld->fb_notif.notifier_call = fb_notifier_callback;

	rc = fb_register_client(&new_ld->fb_notif);
	if (unlikely(rc))
		goto error;

	for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++) {
		rc = class_device_create_file(&new_ld->class_dev,
					      &lcd_class_device_attributes[i]);
		if (unlikely(rc)) {
			while (--i >= 0)
				class_device_remove_file(&new_ld->class_dev,
							 &lcd_class_device_attributes[i]);
			class_device_unregister(&new_ld->class_dev);
			/* No need to kfree(new_ld) since release() method was called */
			return ERR_PTR(rc);
		}
	}

	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)
{
	int i;

	if (!ld)
		return;

	pr_debug("lcd_device_unregister: name=%s\n", ld->class_dev.class_id);

	for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++)
		class_device_remove_file(&ld->class_dev,
					 &lcd_class_device_attributes[i]);

	down(&ld->sem);
	ld->props = NULL;
	up(&ld->sem);

	fb_unregister_client(&ld->fb_notif);

	class_device_unregister(&ld->class_dev);
}
EXPORT_SYMBOL(lcd_device_unregister);

static void __exit lcd_class_exit(void)
{
	class_unregister(&lcd_class);
}

static int __init lcd_class_init(void)
{
	return class_register(&lcd_class);
}

/*
 * 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 LT	16
	17	static ssize_t lcd_show_power(struct class_device cdev, char buf)
	18	{
	19	int rc;
	20	struct lcd_device *ld = to_lcd_device(cdev);
	21
	22	down(&ld->sem);
	23	if (likely(ld->props && ld->props->get_power))
	24	rc = sprintf(buf, "%d\n", ld->props->get_power(ld));
	25	else
	26	rc = -ENXIO;
	27	up(&ld->sem);
	28
	29	return rc;
	30	}
	31
	32	static ssize_t lcd_store_power(struct class_device cdev, const char buf, size_t count)
	33	{
	34	int rc, power;
	35	char *endp;
	36	struct lcd_device *ld = to_lcd_device(cdev);
	37
	38	power = simple_strtoul(buf, &endp, 0);
	39	if (endp && !isspace(endp))
	40	return -EINVAL;
	41
	42	down(&ld->sem);
	43	if (likely(ld->props && ld->props->set_power)) {
	44	pr_debug("lcd: set power to %d\n", power);
	45	ld->props->set_power(ld, power);
	46	rc = count;
	47	} else
	48	rc = -ENXIO;
	49	up(&ld->sem);
	50
	51	return rc;
	52	}
	53
	54	static ssize_t lcd_show_contrast(struct class_device cdev, char buf)
	55	{
	56	int rc;
	57	struct lcd_device *ld = to_lcd_device(cdev);
	58
	59	down(&ld->sem);
	60	if (likely(ld->props && ld->props->get_contrast))
	61	rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld));
	62	else
	63	rc = -ENXIO;
	64	up(&ld->sem);
	65
	66	return rc;
	67	}
	68
	69	static ssize_t lcd_store_contrast(struct class_device cdev, const char buf, size_t count)
	70	{
	71	int rc, contrast;
	72	char *endp;
	73	struct lcd_device *ld = to_lcd_device(cdev);
	74
	75	contrast = simple_strtoul(buf, &endp, 0);
	76	if (endp && !isspace(endp))
	77	return -EINVAL;
	78
	79	down(&ld->sem);
80	if (likely(ld->props && ld->props->set_contrast)) {
81	pr_debug("lcd: set contrast to %d\n", contrast);
82	ld->props->set_contrast(ld, contrast);
83	rc = count;
84	} else
85	rc = -ENXIO;
86	up(&ld->sem);
87
88	return rc;
89	}
90
91	static ssize_t lcd_show_max_contrast(struct class_device cdev, char buf)
92	{
93	int rc;
94	struct lcd_device *ld = to_lcd_device(cdev);
95
96	down(&ld->sem);
97	if (likely(ld->props))
98	rc = sprintf(buf, "%d\n", ld->props->max_contrast);
99	else
100	rc = -ENXIO;
101	up(&ld->sem);
102
103	return rc;
104	}
105
106	static void lcd_class_release(struct class_device *dev)
107	{
108	struct lcd_device *ld = to_lcd_device(dev);
109	kfree(ld);
110	}
111
112	static struct class lcd_class = {
113	.name = "lcd",
114	.release = lcd_class_release,
115	};
116
117	#define DECLARE_ATTR(_name,_mode,_show,_store) \
118	{ \
119	.attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \
120	.show = _show, \
121	.store = _store, \
122	}
123
124	static struct class_device_attribute lcd_class_device_attributes[] = {
125	DECLARE_ATTR(power, 0644, lcd_show_power, lcd_store_power),
126	DECLARE_ATTR(contrast, 0644, lcd_show_contrast, lcd_store_contrast),
127	DECLARE_ATTR(max_contrast, 0444, lcd_show_max_contrast, NULL),
128	};
129
130	/* This callback gets called when something important happens inside a
131	* framebuffer driver. We're looking if that important event is blanking,
132	* and if it is, we're switching lcd power as well ...
133	*/
134	static int fb_notifier_callback(struct notifier_block *self,
135	unsigned long event, void *data)
136	{
137	struct lcd_device *ld;
138	struct fb_event evdata =(struct fb_event )data;
139
140	/* If we aren't interested in this event, skip it immediately ... */
141	if (event != FB_EVENT_BLANK)
142	return 0;
143
144	ld = container_of(self, struct lcd_device, fb_notif);
145	down(&ld->sem);
146	if (ld->props)
147	if (!ld->props->check_fb \|\| ld->props->check_fb(evdata->info))
148	ld->props->set_power(ld, (int )evdata->data);
149	up(&ld->sem);
150	return 0;
151	}
152
153	/**
154	* lcd_device_register - register a new object of lcd_device class.
155	* @name: the name of the new object(must be the same as the name of the
156	* respective framebuffer device).
157	* @devdata: an optional pointer to be stored in the class_device. The
158	* methods may retrieve it by using class_get_devdata(ld->class_dev).
159	* @lp: the lcd properties structure.
160	*
161	* Creates and registers a new lcd class_device. Returns either an ERR_PTR()
162	* or a pointer to the newly allocated device.
163	*/
164	struct lcd_device lcd_device_register(const char name, void *devdata,
165	struct lcd_properties *lp)
166	{
167	int i, rc;
168	struct lcd_device *new_ld;
169
170	pr_debug("lcd_device_register: name=%s\n", name);
171
172	new_ld = kmalloc(sizeof(struct lcd_device), GFP_KERNEL);
173	if (unlikely(!new_ld))
174	return ERR_PTR(ENOMEM);
175
176	init_MUTEX(&new_ld->sem);
177	new_ld->props = lp;
178	memset(&new_ld->class_dev, 0, sizeof(new_ld->class_dev));
179	new_ld->class_dev.class = &lcd_class;
180	strlcpy(new_ld->class_dev.class_id, name, KOBJ_NAME_LEN);
181	class_set_devdata(&new_ld->class_dev, devdata);
182
183	rc = class_device_register(&new_ld->class_dev);
184	if (unlikely(rc)) {
185	error: kfree(new_ld);
186	return ERR_PTR(rc);
187	}
188
189	memset(&new_ld->fb_notif, 0, sizeof(new_ld->fb_notif));
190	new_ld->fb_notif.notifier_call = fb_notifier_callback;
191
192	rc = fb_register_client(&new_ld->fb_notif);
193	if (unlikely(rc))
194	goto error;
195
196	for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++) {
197	rc = class_device_create_file(&new_ld->class_dev,
198	&lcd_class_device_attributes[i]);
199	if (unlikely(rc)) {
200	while (--i >= 0)
201	class_device_remove_file(&new_ld->class_dev,
202	&lcd_class_device_attributes[i]);
203	class_device_unregister(&new_ld->class_dev);
204	/* No need to kfree(new_ld) since release() method was called */
205	return ERR_PTR(rc);
206	}
207	}
208
209	return new_ld;
210	}
211	EXPORT_SYMBOL(lcd_device_register);
212
213	/**
214	* lcd_device_unregister - unregisters a object of lcd_device class.
215	* @ld: the lcd device object to be unregistered and freed.
216	*
217	* Unregisters a previously registered via lcd_device_register object.
218	*/
219	void lcd_device_unregister(struct lcd_device *ld)
220	{
221	int i;
222
223	if (!ld)
224	return;
225
226	pr_debug("lcd_device_unregister: name=%s\n", ld->class_dev.class_id);
227
228	for (i = 0; i < ARRAY_SIZE(lcd_class_device_attributes); i++)
229	class_device_remove_file(&ld->class_dev,
230	&lcd_class_device_attributes[i]);
231
232	down(&ld->sem);
233	ld->props = NULL;
234	up(&ld->sem);
235
236	fb_unregister_client(&ld->fb_notif);
237
238	class_device_unregister(&ld->class_dev);
239	}
240	EXPORT_SYMBOL(lcd_device_unregister);
241
242	static void __exit lcd_class_exit(void)
243	{
244	class_unregister(&lcd_class);
245	}
246
247	static int __init lcd_class_init(void)
248	{
249	return class_register(&lcd_class);
250	}
251
252	/*
253	* if this is compiled into the kernel, we need to ensure that the
254	* class is registered before users of the class try to register lcd's
255	*/
256	postcore_initcall(lcd_class_init);
257	module_exit(lcd_class_exit);
258
259	MODULE_LICENSE("GPL");
260	MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>");
261	MODULE_DESCRIPTION("LCD Lowlevel Control Abstraction");