[mirror_ubuntu-bionic-kernel.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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/jiffies.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/module.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 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(system_freezable_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);

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

	/* Only start polling if polling is enabled */
	if (dev->poll_interval > 0) {
		dev->poll(dev);
		input_polldev_queue_work(dev);
	}

	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);

	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 int interval;
	int err;

	err = kstrtouint(buf, 0, &interval);
	if (err)
		return err;

	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
};

static const struct attribute_group *input_polldev_attribute_groups[] = {
	&input_polldev_attribute_group,
	NULL
};

/**
 * input_allocate_polled_device - allocate memory for 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);

struct input_polled_devres {
	struct input_polled_dev *polldev;
};

static int devm_input_polldev_match(struct device *dev, void *res, void *data)
{
	struct input_polled_devres *devres = res;

	return devres->polldev == data;
}

static void devm_input_polldev_release(struct device *dev, void *res)
{
	struct input_polled_devres *devres = res;
	struct input_polled_dev *polldev = devres->polldev;

	dev_dbg(dev, "%s: dropping reference/freeing %s\n",
		__func__, dev_name(&polldev->input->dev));

	input_put_device(polldev->input);
	kfree(polldev);
}

static void devm_input_polldev_unregister(struct device *dev, void *res)
{
	struct input_polled_devres *devres = res;
	struct input_polled_dev *polldev = devres->polldev;

	dev_dbg(dev, "%s: unregistering device %s\n",
		__func__, dev_name(&polldev->input->dev));
	input_unregister_device(polldev->input);

	/*
	 * Note that we are still holding extra reference to the input
	 * device so it will stick around until devm_input_polldev_release()
	 * is called.
	 */
}

/**
 * devm_input_allocate_polled_device - allocate managed polled device
 * @dev: device owning the polled device being created
 *
 * Returns prepared &struct input_polled_dev or %NULL.
 *
 * Managed polled input devices do not need to be explicitly unregistered
 * or freed as it will be done automatically when owner device unbinds
 * from * its driver (or binding fails). Once such managed polled device
 * is allocated, it is ready to be set up and registered in the same
 * fashion as regular polled input devices (using
 * input_register_polled_device() function).
 *
 * If you want to manually unregister and free such managed polled devices,
 * it can be still done by calling input_unregister_polled_device() and
 * input_free_polled_device(), although it is rarely needed.
 *
 * NOTE: the owner device is set up as parent of input device and users
 * should not override it.
 */
struct input_polled_dev *devm_input_allocate_polled_device(struct device *dev)
{
	struct input_polled_dev *polldev;
	struct input_polled_devres *devres;

	devres = devres_alloc(devm_input_polldev_release, sizeof(*devres),
			      GFP_KERNEL);
	if (!devres)
		return NULL;

	polldev = input_allocate_polled_device();
	if (!polldev) {
		devres_free(devres);
		return NULL;
	}

	polldev->input->dev.parent = dev;
	polldev->devres_managed = true;

	devres->polldev = polldev;
	devres_add(dev, devres);

	return polldev;
}
EXPORT_SYMBOL(devm_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) {
		if (dev->devres_managed)
			WARN_ON(devres_destroy(dev->input->dev.parent,
						devm_input_polldev_release,
						devm_input_polldev_match,
						dev));
		input_put_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
 * corresponding input_dev structure.
 */
int input_register_polled_device(struct input_polled_dev *dev)
{
	struct input_polled_devres *devres = NULL;
	struct input_dev *input = dev->input;
	int error;

	if (dev->devres_managed) {
		devres = devres_alloc(devm_input_polldev_unregister,
				      sizeof(*devres), GFP_KERNEL);
		if (!devres)
			return -ENOMEM;

		devres->polldev = dev;
	}

	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;

	input->dev.groups = input_polldev_attribute_groups;

	error = input_register_device(input);
	if (error) {
		devres_free(devres);
		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);

	if (dev->devres_managed) {
		dev_dbg(input->dev.parent, "%s: registering %s with devres.\n",
			__func__, dev_name(&input->dev));
		devres_add(input->dev.parent, devres);
	}

	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)
{
	if (dev->devres_managed)
		WARN_ON(devres_destroy(dev->input->dev.parent,
					devm_input_polldev_unregister,
					devm_input_polldev_match,
					dev));

	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
da0c4901 JP	11	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
da0c4901 JP	12
0dcd8073	13	#include <linux/jiffies.h>
5a0e3ad6	14	#include <linux/slab.h>
0dcd8073	15	#include <linux/mutex.h>
e490ebdc	16	#include <linux/workqueue.h>
d2d8442d	17	#include <linux/module.h>
0dcd8073 DT	18	#include <linux/input-polldev.h>
0dcd8073 DT	19
36bd52a4 EP	20	MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
	21	MODULE_DESCRIPTION("Generic implementation of a polled input device");
	22	MODULE_LICENSE("GPL v2");
	23	MODULE_VERSION("0.1");
	24
dad725d0	25	static void input_polldev_queue_work(struct input_polled_dev *dev)
0dcd8073	26	{
374766bc	27	unsigned long delay;
0dcd8073	28
374766bc SH	29	delay = msecs_to_jiffies(dev->poll_interval);
	30	if (delay >= HZ)
	31	delay = round_jiffies_relative(delay);
	32
e490ebdc	33	queue_delayed_work(system_freezable_wq, &dev->work, delay);
0dcd8073 DT	34	}
0dcd8073 DT	35
dad725d0 SO	36	static void input_polled_device_work(struct work_struct *work)
	37	{
	38	struct input_polled_dev *dev =
	39	container_of(work, struct input_polled_dev, work.work);
	40
	41	dev->poll(dev);
	42	input_polldev_queue_work(dev);
	43	}
	44
0dcd8073 DT	45	static int input_open_polled_device(struct input_dev *input)
0dcd8073 DT	46	{
3797fec1	47	struct input_polled_dev *dev = input_get_drvdata(input);
0dcd8073	48
b0aba1e6 SO	49	if (dev->open)
b0aba1e6 SO	50	dev->open(dev);
0dcd8073	51
11bb4cc7	52	/* Only start polling if polling is enabled */
5e3e4eb1 DT	53	if (dev->poll_interval > 0) {
	54	dev->poll(dev);
	55	input_polldev_queue_work(dev);
	56	}
0dcd8073 DT	57
	58	return 0;
	59	}
	60
	61	static void input_close_polled_device(struct input_dev *input)
	62	{
3797fec1	63	struct input_polled_dev *dev = input_get_drvdata(input);
0dcd8073	64
374766bc	65	cancel_delayed_work_sync(&dev->work);
b0aba1e6 SO	66
	67	if (dev->close)
	68	dev->close(dev);
0dcd8073 DT	69	}
0dcd8073 DT	70
dad725d0 SO	71	/* SYSFS interface */
	72
	73	static ssize_t input_polldev_get_poll(struct device *dev,
	74	struct device_attribute attr, char buf)
	75	{
	76	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	77
	78	return sprintf(buf, "%d\n", polldev->poll_interval);
	79	}
	80
	81	static ssize_t input_polldev_set_poll(struct device *dev,
	82	struct device_attribute attr, const char buf,
	83	size_t count)
	84	{
	85	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	86	struct input_dev *input = polldev->input;
76496e7a JD	87	unsigned int interval;
76496e7a JD	88	int err;
dad725d0	89
76496e7a JD	90	err = kstrtouint(buf, 0, &interval);
	91	if (err)
	92	return err;
dad725d0 SO	93
	94	if (interval < polldev->poll_interval_min)
	95	return -EINVAL;
	96
	97	if (interval > polldev->poll_interval_max)
	98	return -EINVAL;
	99
	100	mutex_lock(&input->mutex);
	101
	102	polldev->poll_interval = interval;
	103
	104	if (input->users) {
	105	cancel_delayed_work_sync(&polldev->work);
	106	if (polldev->poll_interval > 0)
	107	input_polldev_queue_work(polldev);
	108	}
	109
	110	mutex_unlock(&input->mutex);
	111
	112	return count;
	113	}
	114
	115	static DEVICE_ATTR(poll, S_IRUGO \| S_IWUSR, input_polldev_get_poll,
	116	input_polldev_set_poll);
	117
	118
	119	static ssize_t input_polldev_get_max(struct device *dev,
	120	struct device_attribute attr, char buf)
	121	{
	122	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	123
	124	return sprintf(buf, "%d\n", polldev->poll_interval_max);
	125	}
	126
	127	static DEVICE_ATTR(max, S_IRUGO, input_polldev_get_max, NULL);
	128
	129	static ssize_t input_polldev_get_min(struct device *dev,
	130	struct device_attribute attr, char buf)
	131	{
	132	struct input_polled_dev *polldev = dev_get_drvdata(dev);
	133
	134	return sprintf(buf, "%d\n", polldev->poll_interval_min);
	135	}
	136
	137	static DEVICE_ATTR(min, S_IRUGO, input_polldev_get_min, NULL);
	138
	139	static struct attribute *sysfs_attrs[] = {
	140	&dev_attr_poll.attr,
	141	&dev_attr_max.attr,
	142	&dev_attr_min.attr,
	143	NULL
	144	};
	145
	146	static struct attribute_group input_polldev_attribute_group = {
	147	.attrs = sysfs_attrs
	148	};
	149
d1fefd5b DT	150	static const struct attribute_group *input_polldev_attribute_groups[] = {
	151	&input_polldev_attribute_group,
	152	NULL
	153	};
	154
0dcd8073	155	/**
2546bcc2	156	* input_allocate_polled_device - allocate memory for polled device
0dcd8073 DT	157	*
	158	* The function allocates memory for a polled device and also
	159	* for an input device associated with this polled device.
	160	*/
	161	struct input_polled_dev *input_allocate_polled_device(void)
	162	{
	163	struct input_polled_dev *dev;
	164
	165	dev = kzalloc(sizeof(struct input_polled_dev), GFP_KERNEL);
	166	if (!dev)
	167	return NULL;
	168
	169	dev->input = input_allocate_device();
	170	if (!dev->input) {
	171	kfree(dev);
	172	return NULL;
	173	}
	174
	175	return dev;
	176	}
	177	EXPORT_SYMBOL(input_allocate_polled_device);
	178
bf1de976 DT	179	struct input_polled_devres {
	180	struct input_polled_dev *polldev;
	181	};
	182
	183	static int devm_input_polldev_match(struct device dev, void res, void *data)
	184	{
	185	struct input_polled_devres *devres = res;
	186
	187	return devres->polldev == data;
	188	}
	189
	190	static void devm_input_polldev_release(struct device dev, void res)
	191	{
	192	struct input_polled_devres *devres = res;
	193	struct input_polled_dev *polldev = devres->polldev;
	194
	195	dev_dbg(dev, "%s: dropping reference/freeing %s\n",
	196	__func__, dev_name(&polldev->input->dev));
	197
	198	input_put_device(polldev->input);
	199	kfree(polldev);
	200	}
	201
	202	static void devm_input_polldev_unregister(struct device dev, void res)
	203	{
	204	struct input_polled_devres *devres = res;
	205	struct input_polled_dev *polldev = devres->polldev;
	206
	207	dev_dbg(dev, "%s: unregistering device %s\n",
	208	__func__, dev_name(&polldev->input->dev));
	209	input_unregister_device(polldev->input);
	210
	211	/*
	212	* Note that we are still holding extra reference to the input
	213	* device so it will stick around until devm_input_polldev_release()
	214	* is called.
	215	*/
	216	}
	217
	218	/**
	219	* devm_input_allocate_polled_device - allocate managed polled device
	220	* @dev: device owning the polled device being created
	221	*
	222	* Returns prepared &struct input_polled_dev or %NULL.
	223	*
	224	* Managed polled input devices do not need to be explicitly unregistered
	225	* or freed as it will be done automatically when owner device unbinds
	226	* from * its driver (or binding fails). Once such managed polled device
	227	* is allocated, it is ready to be set up and registered in the same
	228	* fashion as regular polled input devices (using
	229	* input_register_polled_device() function).
	230	*
	231	* If you want to manually unregister and free such managed polled devices,
	232	* it can be still done by calling input_unregister_polled_device() and
	233	* input_free_polled_device(), although it is rarely needed.
	234	*
	235	* NOTE: the owner device is set up as parent of input device and users
	236	* should not override it.
	237	*/
	238	struct input_polled_dev devm_input_allocate_polled_device(struct device dev)
	239	{
	240	struct input_polled_dev *polldev;
	241	struct input_polled_devres *devres;
	242
243	devres = devres_alloc(devm_input_polldev_release, sizeof(*devres),
244	GFP_KERNEL);
245	if (!devres)
246	return NULL;
247
248	polldev = input_allocate_polled_device();
249	if (!polldev) {
250	devres_free(devres);
251	return NULL;
252	}
253
254	polldev->input->dev.parent = dev;
255	polldev->devres_managed = true;
256
257	devres->polldev = polldev;
258	devres_add(dev, devres);
259
260	return polldev;
261	}
262	EXPORT_SYMBOL(devm_input_allocate_polled_device);
263
0dcd8073 DT	264	/**
	265	* input_free_polled_device - free memory allocated for polled device
	266	* @dev: device to free
	267	*
	268	* The function frees memory allocated for polling device and drops
36203c4f	269	* reference to the associated input device.
0dcd8073 DT	270	*/
	271	void input_free_polled_device(struct input_polled_dev *dev)
	272	{
	273	if (dev) {
bf1de976 DT	274	if (dev->devres_managed)
	275	WARN_ON(devres_destroy(dev->input->dev.parent,
	276	devm_input_polldev_release,
	277	devm_input_polldev_match,
	278	dev));
	279	input_put_device(dev->input);
0dcd8073 DT	280	kfree(dev);
	281	}
	282	}
	283	EXPORT_SYMBOL(input_free_polled_device);
	284
	285	/**
	286	* input_register_polled_device - register polled device
	287	* @dev: device to register
	288	*
	289	* The function registers previously initialized polled input device
	290	* with input layer. The device should be allocated with call to
	291	* input_allocate_polled_device(). Callers should also set up poll()
	292	* method and set up capabilities (id, name, phys, bits) of the
2546bcc2	293	* corresponding input_dev structure.
0dcd8073 DT	294	*/
	295	int input_register_polled_device(struct input_polled_dev *dev)
	296	{
bf1de976	297	struct input_polled_devres *devres = NULL;
0dcd8073	298	struct input_dev *input = dev->input;
dad725d0	299	int error;
0dcd8073	300
bf1de976 DT	301	if (dev->devres_managed) {
	302	devres = devres_alloc(devm_input_polldev_unregister,
	303	sizeof(*devres), GFP_KERNEL);
	304	if (!devres)
	305	return -ENOMEM;
	306
	307	devres->polldev = dev;
	308	}
	309
3797fec1	310	input_set_drvdata(input, dev);
0dcd8073	311	INIT_DELAYED_WORK(&dev->work, input_polled_device_work);
d1fefd5b	312
0dcd8073 DT	313	if (!dev->poll_interval)
0dcd8073 DT	314	dev->poll_interval = 500;
dad725d0 SO	315	if (!dev->poll_interval_max)
dad725d0 SO	316	dev->poll_interval_max = dev->poll_interval;
d1fefd5b	317
0dcd8073 DT	318	input->open = input_open_polled_device;
	319	input->close = input_close_polled_device;
	320
d1fefd5b DT	321	input->dev.groups = input_polldev_attribute_groups;
d1fefd5b DT	322
dad725d0	323	error = input_register_device(input);
bf1de976 DT	324	if (error) {
bf1de976 DT	325	devres_free(devres);
dad725d0	326	return error;
bf1de976	327	}
dad725d0	328
36203c4f DT	329	/*
	330	* Take extra reference to the underlying input device so
	331	* that it survives call to input_unregister_polled_device()
	332	* and is deleted only after input_free_polled_device()
	333	* has been invoked. This is needed to ease task of freeing
	334	* sparse keymaps.
	335	*/
	336	input_get_device(input);
	337
bf1de976 DT	338	if (dev->devres_managed) {
	339	dev_dbg(input->dev.parent, "%s: registering %s with devres.\n",
	340	__func__, dev_name(&input->dev));
	341	devres_add(input->dev.parent, devres);
	342	}
	343
dad725d0	344	return 0;
0dcd8073 DT	345	}
	346	EXPORT_SYMBOL(input_register_polled_device);
	347
	348	/**
	349	* input_unregister_polled_device - unregister polled device
	350	* @dev: device to unregister
	351	*
	352	* The function unregisters previously registered polled input
	353	* device from input layer. Polling is stopped and device is
	354	* ready to be freed with call to input_free_polled_device().
0dcd8073 DT	355	*/
	356	void input_unregister_polled_device(struct input_polled_dev *dev)
	357	{
bf1de976 DT	358	if (dev->devres_managed)
	359	WARN_ON(devres_destroy(dev->input->dev.parent,
	360	devm_input_polldev_unregister,
	361	devm_input_polldev_match,
	362	dev));
	363
0dcd8073	364	input_unregister_device(dev->input);
0dcd8073 DT	365	}
0dcd8073 DT	366	EXPORT_SYMBOL(input_unregister_polled_device);