[linux-2.6-block.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/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>
	12	#include <linux/mutex.h>
	13	#include <linux/input-polldev.h>
	14
36bd52a4 EP	15	MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
	16	MODULE_DESCRIPTION("Generic implementation of a polled input device");
	17	MODULE_LICENSE("GPL v2");
	18	MODULE_VERSION("0.1");
	19
0dcd8073 DT	20	static DEFINE_MUTEX(polldev_mutex);
	21	static int polldev_users;
	22	static struct workqueue_struct *polldev_wq;
	23
	24	static int input_polldev_start_workqueue(void)
	25	{
	26	int retval;
	27
	28	retval = mutex_lock_interruptible(&polldev_mutex);
	29	if (retval)
	30	return retval;
	31
	32	if (!polldev_users) {
	33	polldev_wq = create_singlethread_workqueue("ipolldevd");
	34	if (!polldev_wq) {
	35	printk(KERN_ERR "input-polldev: failed to create "
	36	"ipolldevd workqueue\n");
	37	retval = -ENOMEM;
	38	goto out;
	39	}
	40	}
	41
	42	polldev_users++;
	43
	44	out:
	45	mutex_unlock(&polldev_mutex);
	46	return retval;
	47	}
	48
	49	static void input_polldev_stop_workqueue(void)
	50	{
	51	mutex_lock(&polldev_mutex);
	52
	53	if (!--polldev_users)
	54	destroy_workqueue(polldev_wq);
	55
	56	mutex_unlock(&polldev_mutex);
	57	}
	58
dad725d0	59	static void input_polldev_queue_work(struct input_polled_dev *dev)
0dcd8073	60	{
374766bc	61	unsigned long delay;
0dcd8073	62
374766bc SH	63	delay = msecs_to_jiffies(dev->poll_interval);
	64	if (delay >= HZ)
	65	delay = round_jiffies_relative(delay);
	66
	67	queue_delayed_work(polldev_wq, &dev->work, delay);
0dcd8073 DT	68	}
0dcd8073 DT	69
dad725d0 SO	70	static void input_polled_device_work(struct work_struct *work)
	71	{
	72	struct input_polled_dev *dev =
	73	container_of(work, struct input_polled_dev, work.work);
	74
	75	dev->poll(dev);
	76	input_polldev_queue_work(dev);
	77	}
	78
0dcd8073 DT	79	static int input_open_polled_device(struct input_dev *input)
0dcd8073 DT	80	{
3797fec1	81	struct input_polled_dev *dev = input_get_drvdata(input);
0dcd8073 DT	82	int error;
	83
	84	error = input_polldev_start_workqueue();
	85	if (error)
	86	return error;
	87
b0aba1e6 SO	88	if (dev->open)
b0aba1e6 SO	89	dev->open(dev);
0dcd8073	90
11bb4cc7 SO	91	/* Only start polling if polling is enabled */
	92	if (dev->poll_interval > 0)
	93	queue_delayed_work(polldev_wq, &dev->work, 0);
0dcd8073 DT	94
	95	return 0;
	96	}
	97
	98	static void input_close_polled_device(struct input_dev *input)
	99	{
3797fec1	100	struct input_polled_dev *dev = input_get_drvdata(input);
0dcd8073	101
374766bc	102	cancel_delayed_work_sync(&dev->work);
d9c4f846 SO	103	/*
	104	* Clean up work struct to remove references to the workqueue.
	105	* It may be destroyed by the next call. This causes problems
	106	* at next device open-close in case of poll_interval == 0.
	107	*/
	108	INIT_DELAYED_WORK(&dev->work, dev->work.work.func);
0dcd8073	109	input_polldev_stop_workqueue();
b0aba1e6 SO	110
	111	if (dev->close)
	112	dev->close(dev);
0dcd8073 DT	113	}
0dcd8073 DT	114
dad725d0 SO	115	/* SYSFS interface */
	116
	117	static ssize_t input_polldev_get_poll(struct device *dev,
	118	struct device_attribute attr, char buf)
	119	{
	120	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	121
	122	return sprintf(buf, "%d\n", polldev->poll_interval);
	123	}
	124
	125	static ssize_t input_polldev_set_poll(struct device *dev,
	126	struct device_attribute attr, const char buf,
	127	size_t count)
	128	{
	129	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	130	struct input_dev *input = polldev->input;
	131	unsigned long interval;
	132
	133	if (strict_strtoul(buf, 0, &interval))
	134	return -EINVAL;
	135
	136	if (interval < polldev->poll_interval_min)
	137	return -EINVAL;
	138
	139	if (interval > polldev->poll_interval_max)
	140	return -EINVAL;
	141
	142	mutex_lock(&input->mutex);
	143
	144	polldev->poll_interval = interval;
	145
	146	if (input->users) {
	147	cancel_delayed_work_sync(&polldev->work);
	148	if (polldev->poll_interval > 0)
	149	input_polldev_queue_work(polldev);
	150	}
	151
	152	mutex_unlock(&input->mutex);
	153
	154	return count;
	155	}
	156
	157	static DEVICE_ATTR(poll, S_IRUGO \| S_IWUSR, input_polldev_get_poll,
	158	input_polldev_set_poll);
	159
	160
	161	static ssize_t input_polldev_get_max(struct device *dev,
	162	struct device_attribute attr, char buf)
	163	{
	164	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	165
	166	return sprintf(buf, "%d\n", polldev->poll_interval_max);
	167	}
	168
	169	static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);
	170
	171	static ssize_t input_polldev_get_min(struct device *dev,
	172	struct device_attribute attr, char buf)
	173	{
	174	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	175
	176	return sprintf(buf, "%d\n", polldev->poll_interval_min);
	177	}
	178
179	static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);
180
181	static struct attribute *sysfs_attrs[] = {
182	&dev_attr_poll.attr,
183	&dev_attr_max.attr,
184	&dev_attr_min.attr,
185	NULL
186	};
187
188	static struct attribute_group input_polldev_attribute_group = {
189	.attrs = sysfs_attrs
190	};
191
0dcd8073 DT	192	/**
	193	* input_allocate_polled_device - allocated memory polled device
	194	*
	195	* The function allocates memory for a polled device and also
	196	* for an input device associated with this polled device.
	197	*/
	198	struct input_polled_dev *input_allocate_polled_device(void)
	199	{
	200	struct input_polled_dev *dev;
	201
	202	dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
	203	if (!dev)
	204	return NULL;
	205
	206	dev->input = input_allocate_device();
	207	if (!dev->input) {
	208	kfree(dev);
	209	return NULL;
	210	}
	211
	212	return dev;
	213	}
	214	EXPORT_SYMBOL(input_allocate_polled_device);
	215
	216	/**
	217	* input_free_polled_device - free memory allocated for polled device
	218	* @dev: device to free
	219	*
	220	* The function frees memory allocated for polling device and drops
36203c4f	221	* reference to the associated input device.
0dcd8073 DT	222	*/
	223	void input_free_polled_device(struct input_polled_dev *dev)
	224	{
	225	if (dev) {
	226	input_free_device(dev->input);
	227	kfree(dev);
	228	}
	229	}
	230	EXPORT_SYMBOL(input_free_polled_device);
	231
	232	/**
	233	* input_register_polled_device - register polled device
	234	* @dev: device to register
	235	*
	236	* The function registers previously initialized polled input device
	237	* with input layer. The device should be allocated with call to
	238	* input_allocate_polled_device(). Callers should also set up poll()
	239	* method and set up capabilities (id, name, phys, bits) of the
	240	* corresponing input_dev structure.
	241	*/
	242	int input_register_polled_device(struct input_polled_dev *dev)
	243	{
	244	struct input_dev *input = dev->input;
dad725d0	245	int error;
0dcd8073	246
3797fec1	247	input_set_drvdata(input, dev);
0dcd8073 DT	248	INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
	249	if (!dev->poll_interval)
	250	dev->poll_interval = 500;
dad725d0 SO	251	if (!dev->poll_interval_max)
dad725d0 SO	252	dev->poll_interval_max = dev->poll_interval;
0dcd8073 DT	253	input->open = input_open_polled_device;
	254	input->close = input_close_polled_device;
	255
dad725d0 SO	256	error = input_register_device(input);
	257	if (error)
	258	return error;
	259
	260	error = sysfs_create_group(&input->dev.kobj,
	261	&input_polldev_attribute_group);
	262	if (error) {
	263	input_unregister_device(input);
	264	return error;
	265	}
	266
36203c4f DT	267	/*
	268	* Take extra reference to the underlying input device so
	269	* that it survives call to input_unregister_polled_device()
	270	* and is deleted only after input_free_polled_device()
	271	* has been invoked. This is needed to ease task of freeing
	272	* sparse keymaps.
	273	*/
	274	input_get_device(input);
	275
dad725d0	276	return 0;
0dcd8073 DT	277	}
	278	EXPORT_SYMBOL(input_register_polled_device);
	279
	280	/**
	281	* input_unregister_polled_device - unregister polled device
	282	* @dev: device to unregister
	283	*
	284	* The function unregisters previously registered polled input
	285	* device from input layer. Polling is stopped and device is
	286	* ready to be freed with call to input_free_polled_device().
0dcd8073 DT	287	*/
	288	void input_unregister_polled_device(struct input_polled_dev *dev)
	289	{
dad725d0 SO	290	sysfs_remove_group(&dev->input->dev.kobj,
	291	&input_polldev_attribute_group);
	292
0dcd8073	293	input_unregister_device(dev->input);
0dcd8073 DT	294	}
	295	EXPORT_SYMBOL(input_unregister_polled_device);
	296