[net-next-2.6.git] / drivers / input / input-polldev.c

/*
 * Generic implementation of a polled input device

 * Copyright (c) 2007 Dmitry Torokhov
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/jiffies.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/input-polldev.h>

MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
MODULE_DESCRIPTION("Generic implementation of a polled input device");
MODULE_LICENSE("GPL v2");
MODULE_VERSION("0.1");

static DEFINE_MUTEX(polldev_mutex);
static int polldev_users;
static struct workqueue_struct *polldev_wq;

static int input_polldev_start_workqueue(void)
{
	int retval;

	retval = mutex_lock_interruptible(&polldev_mutex);
	if (retval)
		return retval;

	if (!polldev_users) {
		polldev_wq = create_singlethread_workqueue("ipolldevd");
		if (!polldev_wq) {
			printk(KERN_ERR "input-polldev: failed to create "
				"ipolldevd workqueue\n");
			retval = -ENOMEM;
			goto out;
		}
	}

	polldev_users++;

 out:
	mutex_unlock(&polldev_mutex);
	return retval;
}

static void input_polldev_stop_workqueue(void)
{
	mutex_lock(&polldev_mutex);

	if (!--polldev_users)
		destroy_workqueue(polldev_wq);

	mutex_unlock(&polldev_mutex);
}

static void input_polldev_queue_work(struct input_polled_dev *dev)
{
	unsigned long delay;

	delay = msecs_to_jiffies(dev->poll_interval);
	if (delay >= HZ)
		delay = round_jiffies_relative(delay);

	queue_delayed_work(polldev_wq, &dev->work, delay);
}

static void input_polled_device_work(struct work_struct *work)
{
	struct input_polled_dev *dev =
		container_of(work, struct input_polled_dev, work.work);

	dev->poll(dev);
	input_polldev_queue_work(dev);
}

static int input_open_polled_device(struct input_dev *input)
{
	struct input_polled_dev *dev = input_get_drvdata(input);
	int error;

	error = input_polldev_start_workqueue();
	if (error)
		return error;

	if (dev->open)
		dev->open(dev);

	/* Only start polling if polling is enabled */
	if (dev->poll_interval > 0)
		queue_delayed_work(polldev_wq, &dev->work, 0);

	return 0;
}

static void input_close_polled_device(struct input_dev *input)
{
	struct input_polled_dev *dev = input_get_drvdata(input);

	cancel_delayed_work_sync(&dev->work);
	/*
	 * Clean up work struct to remove references to the workqueue.
	 * It may be destroyed by the next call. This causes problems
	 * at next device open-close in case of poll_interval == 0.
	 */
	INIT_DELAYED_WORK(&dev->work, dev->work.work.func);
	input_polldev_stop_workqueue();

	if (dev->close)
		dev->close(dev);
}

/* SYSFS interface */

static ssize_t input_polldev_get_poll(struct device *dev,
				      struct device_attribute *attr, char *buf)
{
	struct input_polled_dev *polldev = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", polldev->poll_interval);
}

static ssize_t input_polldev_set_poll(struct device *dev,
				struct device_attribute *attr, const char *buf,
				size_t count)
{
	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	struct input_dev *input = polldev->input;
	unsigned long interval;

	if (strict_strtoul(buf, 0, &interval))
		return -EINVAL;

	if (interval < polldev->poll_interval_min)
		return -EINVAL;

	if (interval > polldev->poll_interval_max)
		return -EINVAL;

	mutex_lock(&input->mutex);

	polldev->poll_interval = interval;

	if (input->users) {
		cancel_delayed_work_sync(&polldev->work);
		if (polldev->poll_interval > 0)
			input_polldev_queue_work(polldev);
	}

	mutex_unlock(&input->mutex);

	return count;
}

static DEVICE_ATTR(poll, S_IRUGO | S_IWUSR, input_polldev_get_poll,
					    input_polldev_set_poll);


static ssize_t input_polldev_get_max(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct input_polled_dev *polldev = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", polldev->poll_interval_max);
}

static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);

static ssize_t input_polldev_get_min(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct input_polled_dev *polldev = dev_get_drvdata(dev);

	return sprintf(buf, "%d\n", polldev->poll_interval_min);
}

static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);

static struct attribute *sysfs_attrs[] = {
	&dev_attr_poll.attr,
	&dev_attr_max.attr,
	&dev_attr_min.attr,
	NULL
};

static struct attribute_group input_polldev_attribute_group = {
	.attrs = sysfs_attrs
};

/**
 * input_allocate_polled_device - allocated memory polled device
 *
 * The function allocates memory for a polled device and also
 * for an input device associated with this polled device.
 */
struct input_polled_dev *input_allocate_polled_device(void)
{
	struct input_polled_dev *dev;

	dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
	if (!dev)
		return NULL;

	dev->input = input_allocate_device();
	if (!dev->input) {
		kfree(dev);
		return NULL;
	}

	return dev;
}
EXPORT_SYMBOL(input_allocate_polled_device);

/**
 * input_free_polled_device - free memory allocated for polled device
 * @dev: device to free
 *
 * The function frees memory allocated for polling device and drops
 * reference to the associated input device.
 */
void input_free_polled_device(struct input_polled_dev *dev)
{
	if (dev) {
		input_free_device(dev->input);
		kfree(dev);
	}
}
EXPORT_SYMBOL(input_free_polled_device);

/**
 * input_register_polled_device - register polled device
 * @dev: device to register
 *
 * The function registers previously initialized polled input device
 * with input layer. The device should be allocated with call to
 * input_allocate_polled_device(). Callers should also set up poll()
 * method and set up capabilities (id, name, phys, bits) of the
 * corresponing input_dev structure.
 */
int input_register_polled_device(struct input_polled_dev *dev)
{
	struct input_dev *input = dev->input;
	int error;

	input_set_drvdata(input, dev);
	INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
	if (!dev->poll_interval)
		dev->poll_interval = 500;
	if (!dev->poll_interval_max)
		dev->poll_interval_max = dev->poll_interval;
	input->open = input_open_polled_device;
	input->close = input_close_polled_device;

	error = input_register_device(input);
	if (error)
		return error;

	error = sysfs_create_group(&input->dev.kobj,
				   &input_polldev_attribute_group);
	if (error) {
		input_unregister_device(input);
		return error;
	}

	/*
	 * Take extra reference to the underlying input device so
	 * that it survives call to input_unregister_polled_device()
	 * and is deleted only after input_free_polled_device()
	 * has been invoked. This is needed to ease task of freeing
	 * sparse keymaps.
	 */
	input_get_device(input);

	return 0;
}
EXPORT_SYMBOL(input_register_polled_device);

/**
 * input_unregister_polled_device - unregister polled device
 * @dev: device to unregister
 *
 * The function unregisters previously registered polled input
 * device from input layer. Polling is stopped and device is
 * ready to be freed with call to input_free_polled_device().
 */
void input_unregister_polled_device(struct input_polled_dev *dev)
{
	sysfs_remove_group(&dev->input->dev.kobj,
			   &input_polldev_attribute_group);

	input_unregister_device(dev->input);
}
EXPORT_SYMBOL(input_unregister_polled_device);
Commit	Line	Data
0dcd8073 DT	1	/*
	2	* Generic implementation of a polled input device
	3
	4	* Copyright (c) 2007 Dmitry Torokhov
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms of the GNU General Public License version 2 as published by
	8	* the Free Software Foundation.
	9	*/
	10
	11	#include <linux/jiffies.h>
5a0e3ad6	12	#include <linux/slab.h>
0dcd8073 DT	13	#include <linux/mutex.h>
	14	#include <linux/input-polldev.h>
	15
36bd52a4 EP	16	MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
	17	MODULE_DESCRIPTION("Generic implementation of a polled input device");
	18	MODULE_LICENSE("GPL v2");
	19	MODULE_VERSION("0.1");
	20
0dcd8073 DT	21	static DEFINE_MUTEX(polldev_mutex);
	22	static int polldev_users;
	23	static struct workqueue_struct *polldev_wq;
	24
	25	static int input_polldev_start_workqueue(void)
	26	{
	27	int retval;
	28
	29	retval = mutex_lock_interruptible(&polldev_mutex);
	30	if (retval)
	31	return retval;
	32
	33	if (!polldev_users) {
	34	polldev_wq = create_singlethread_workqueue("ipolldevd");
	35	if (!polldev_wq) {
	36	printk(KERN_ERR "input-polldev: failed to create "
	37	"ipolldevd workqueue\n");
	38	retval = -ENOMEM;
	39	goto out;
	40	}
	41	}
	42
	43	polldev_users++;
	44
	45	out:
	46	mutex_unlock(&polldev_mutex);
	47	return retval;
	48	}
	49
	50	static void input_polldev_stop_workqueue(void)
	51	{
	52	mutex_lock(&polldev_mutex);
	53
	54	if (!--polldev_users)
	55	destroy_workqueue(polldev_wq);
	56
	57	mutex_unlock(&polldev_mutex);
	58	}
	59
dad725d0	60	static void input_polldev_queue_work(struct input_polled_dev *dev)
0dcd8073	61	{
374766bc	62	unsigned long delay;
0dcd8073	63
374766bc SH	64	delay = msecs_to_jiffies(dev->poll_interval);
	65	if (delay >= HZ)
	66	delay = round_jiffies_relative(delay);
	67
	68	queue_delayed_work(polldev_wq, &dev->work, delay);
0dcd8073 DT	69	}
0dcd8073 DT	70
dad725d0 SO	71	static void input_polled_device_work(struct work_struct *work)
	72	{
	73	struct input_polled_dev *dev =
	74	container_of(work, struct input_polled_dev, work.work);
	75
	76	dev->poll(dev);
	77	input_polldev_queue_work(dev);
	78	}
	79
0dcd8073 DT	80	static int input_open_polled_device(struct input_dev *input)
0dcd8073 DT	81	{
3797fec1	82	struct input_polled_dev *dev = input_get_drvdata(input);
0dcd8073 DT	83	int error;
	84
	85	error = input_polldev_start_workqueue();
	86	if (error)
	87	return error;
	88
b0aba1e6 SO	89	if (dev->open)
b0aba1e6 SO	90	dev->open(dev);
0dcd8073	91
11bb4cc7 SO	92	/* Only start polling if polling is enabled */
	93	if (dev->poll_interval > 0)
	94	queue_delayed_work(polldev_wq, &dev->work, 0);
0dcd8073 DT	95
	96	return 0;
	97	}
	98
	99	static void input_close_polled_device(struct input_dev *input)
	100	{
3797fec1	101	struct input_polled_dev *dev = input_get_drvdata(input);
0dcd8073	102
374766bc	103	cancel_delayed_work_sync(&dev->work);
d9c4f846 SO	104	/*
	105	* Clean up work struct to remove references to the workqueue.
	106	* It may be destroyed by the next call. This causes problems
	107	* at next device open-close in case of poll_interval == 0.
	108	*/
	109	INIT_DELAYED_WORK(&dev->work, dev->work.work.func);
0dcd8073	110	input_polldev_stop_workqueue();
b0aba1e6 SO	111
	112	if (dev->close)
	113	dev->close(dev);
0dcd8073 DT	114	}
0dcd8073 DT	115
dad725d0 SO	116	/* SYSFS interface */
	117
	118	static ssize_t input_polldev_get_poll(struct device *dev,
	119	struct device_attribute attr, char buf)
	120	{
	121	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	122
	123	return sprintf(buf, "%d\n", polldev->poll_interval);
	124	}
	125
	126	static ssize_t input_polldev_set_poll(struct device *dev,
	127	struct device_attribute attr, const char buf,
	128	size_t count)
	129	{
	130	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	131	struct input_dev *input = polldev->input;
	132	unsigned long interval;
	133
	134	if (strict_strtoul(buf, 0, &interval))
	135	return -EINVAL;
	136
	137	if (interval < polldev->poll_interval_min)
	138	return -EINVAL;
	139
	140	if (interval > polldev->poll_interval_max)
	141	return -EINVAL;
	142
	143	mutex_lock(&input->mutex);
	144
	145	polldev->poll_interval = interval;
	146
	147	if (input->users) {
	148	cancel_delayed_work_sync(&polldev->work);
	149	if (polldev->poll_interval > 0)
	150	input_polldev_queue_work(polldev);
	151	}
	152
	153	mutex_unlock(&input->mutex);
	154
	155	return count;
	156	}
	157
	158	static DEVICE_ATTR(poll, S_IRUGO \| S_IWUSR, input_polldev_get_poll,
	159	input_polldev_set_poll);
	160
	161
	162	static ssize_t input_polldev_get_max(struct device *dev,
	163	struct device_attribute attr, char buf)
	164	{
	165	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	166
	167	return sprintf(buf, "%d\n", polldev->poll_interval_max);
	168	}
	169
	170	static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);
	171
	172	static ssize_t input_polldev_get_min(struct device *dev,
	173	struct device_attribute attr, char buf)
	174	{
	175	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	176
	177	return sprintf(buf, "%d\n", polldev->poll_interval_min);
	178	}
	179
180	static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);
181
182	static struct attribute *sysfs_attrs[] = {
183	&dev_attr_poll.attr,
184	&dev_attr_max.attr,
185	&dev_attr_min.attr,
186	NULL
187	};
188
189	static struct attribute_group input_polldev_attribute_group = {
190	.attrs = sysfs_attrs
191	};
192
0dcd8073 DT	193	/**
	194	* input_allocate_polled_device - allocated memory polled device
	195	*
	196	* The function allocates memory for a polled device and also
	197	* for an input device associated with this polled device.
	198	*/
	199	struct input_polled_dev *input_allocate_polled_device(void)
	200	{
	201	struct input_polled_dev *dev;
	202
	203	dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
	204	if (!dev)
	205	return NULL;
	206
	207	dev->input = input_allocate_device();
	208	if (!dev->input) {
	209	kfree(dev);
	210	return NULL;
	211	}
	212
	213	return dev;
	214	}
	215	EXPORT_SYMBOL(input_allocate_polled_device);
	216
	217	/**
	218	* input_free_polled_device - free memory allocated for polled device
	219	* @dev: device to free
	220	*
	221	* The function frees memory allocated for polling device and drops
36203c4f	222	* reference to the associated input device.
0dcd8073 DT	223	*/
	224	void input_free_polled_device(struct input_polled_dev *dev)
	225	{
	226	if (dev) {
	227	input_free_device(dev->input);
	228	kfree(dev);
	229	}
	230	}
	231	EXPORT_SYMBOL(input_free_polled_device);
	232
	233	/**
	234	* input_register_polled_device - register polled device
	235	* @dev: device to register
	236	*
	237	* The function registers previously initialized polled input device
	238	* with input layer. The device should be allocated with call to
	239	* input_allocate_polled_device(). Callers should also set up poll()
	240	* method and set up capabilities (id, name, phys, bits) of the
	241	* corresponing input_dev structure.
	242	*/
	243	int input_register_polled_device(struct input_polled_dev *dev)
	244	{
	245	struct input_dev *input = dev->input;
dad725d0	246	int error;
0dcd8073	247
3797fec1	248	input_set_drvdata(input, dev);
0dcd8073 DT	249	INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
	250	if (!dev->poll_interval)
	251	dev->poll_interval = 500;
dad725d0 SO	252	if (!dev->poll_interval_max)
dad725d0 SO	253	dev->poll_interval_max = dev->poll_interval;
0dcd8073 DT	254	input->open = input_open_polled_device;
	255	input->close = input_close_polled_device;
	256
dad725d0 SO	257	error = input_register_device(input);
	258	if (error)
	259	return error;
	260
	261	error = sysfs_create_group(&input->dev.kobj,
	262	&input_polldev_attribute_group);
	263	if (error) {
	264	input_unregister_device(input);
	265	return error;
	266	}
	267
36203c4f DT	268	/*
	269	* Take extra reference to the underlying input device so
	270	* that it survives call to input_unregister_polled_device()
	271	* and is deleted only after input_free_polled_device()
	272	* has been invoked. This is needed to ease task of freeing
	273	* sparse keymaps.
	274	*/
	275	input_get_device(input);
	276
dad725d0	277	return 0;
0dcd8073 DT	278	}
	279	EXPORT_SYMBOL(input_register_polled_device);
	280
	281	/**
	282	* input_unregister_polled_device - unregister polled device
	283	* @dev: device to unregister
	284	*
	285	* The function unregisters previously registered polled input
	286	* device from input layer. Polling is stopped and device is
	287	* ready to be freed with call to input_free_polled_device().
0dcd8073 DT	288	*/
	289	void input_unregister_polled_device(struct input_polled_dev *dev)
	290	{
dad725d0 SO	291	sysfs_remove_group(&dev->input->dev.kobj,
	292	&input_polldev_attribute_group);
	293
0dcd8073	294	input_unregister_device(dev->input);
0dcd8073 DT	295	}
	296	EXPORT_SYMBOL(input_unregister_polled_device);
	297