[linux-2.6-block.git] / drivers / iio / industrialio-event.c

// SPDX-License-Identifier: GPL-2.0-only
/* Industrial I/O event handling
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * Based on elements of hwmon and input subsystems.
 */

#include <linux/anon_inodes.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/kfifo.h>
#include <linux/module.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include <linux/iio/iio.h>
#include "iio_core.h"
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>

/**
 * struct iio_event_interface - chrdev interface for an event line
 * @wait:		wait queue to allow blocking reads of events
 * @det_events:		list of detected events
 * @dev_attr_list:	list of event interface sysfs attribute
 * @flags:		file operations related flags including busy flag.
 * @group:		event interface sysfs attribute group
 * @read_lock:		lock to protect kfifo read operations
 */
struct iio_event_interface {
	wait_queue_head_t	wait;
	DECLARE_KFIFO(det_events, struct iio_event_data, 16);

	struct list_head	dev_attr_list;
	unsigned long		flags;
	struct attribute_group	group;
	struct mutex		read_lock;
};

bool iio_event_enabled(const struct iio_event_interface *ev_int)
{
	return !!test_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
}

/**
 * iio_push_event() - try to add event to the list for userspace reading
 * @indio_dev:		IIO device structure
 * @ev_code:		What event
 * @timestamp:		When the event occurred
 *
 * Note: The caller must make sure that this function is not running
 * concurrently for the same indio_dev more than once.
 *
 * This function may be safely used as soon as a valid reference to iio_dev has
 * been obtained via iio_device_alloc(), but any events that are submitted
 * before iio_device_register() has successfully completed will be silently
 * discarded.
 **/
int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
{
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	struct iio_event_data ev;
	int copied;

	if (!ev_int)
		return 0;

	/* Does anyone care? */
	if (iio_event_enabled(ev_int)) {

		ev.id = ev_code;
		ev.timestamp = timestamp;

		copied = kfifo_put(&ev_int->det_events, ev);
		if (copied != 0)
			wake_up_poll(&ev_int->wait, EPOLLIN);
	}

	return 0;
}
EXPORT_SYMBOL(iio_push_event);

/**
 * iio_event_poll() - poll the event queue to find out if it has data
 * @filep:	File structure pointer to identify the device
 * @wait:	Poll table pointer to add the wait queue on
 *
 * Return: (EPOLLIN | EPOLLRDNORM) if data is available for reading
 *	   or a negative error code on failure
 */
static __poll_t iio_event_poll(struct file *filep,
			     struct poll_table_struct *wait)
{
	struct iio_dev *indio_dev = filep->private_data;
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	__poll_t events = 0;

	if (!indio_dev->info)
		return events;

	poll_wait(filep, &ev_int->wait, wait);

	if (!kfifo_is_empty(&ev_int->det_events))
		events = EPOLLIN | EPOLLRDNORM;

	return events;
}

static ssize_t iio_event_chrdev_read(struct file *filep,
				     char __user *buf,
				     size_t count,
				     loff_t *f_ps)
{
	struct iio_dev *indio_dev = filep->private_data;
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	unsigned int copied;
	int ret;

	if (!indio_dev->info)
		return -ENODEV;

	if (count < sizeof(struct iio_event_data))
		return -EINVAL;

	do {
		if (kfifo_is_empty(&ev_int->det_events)) {
			if (filep->f_flags & O_NONBLOCK)
				return -EAGAIN;

			ret = wait_event_interruptible(ev_int->wait,
					!kfifo_is_empty(&ev_int->det_events) ||
					indio_dev->info == NULL);
			if (ret)
				return ret;
			if (indio_dev->info == NULL)
				return -ENODEV;
		}

		if (mutex_lock_interruptible(&ev_int->read_lock))
			return -ERESTARTSYS;
		ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
		mutex_unlock(&ev_int->read_lock);

		if (ret)
			return ret;

		/*
		 * If we couldn't read anything from the fifo (a different
		 * thread might have been faster) we either return -EAGAIN if
		 * the file descriptor is non-blocking, otherwise we go back to
		 * sleep and wait for more data to arrive.
		 */
		if (copied == 0 && (filep->f_flags & O_NONBLOCK))
			return -EAGAIN;

	} while (copied == 0);

	return copied;
}

static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
{
	struct iio_dev *indio_dev = filep->private_data;
	struct iio_event_interface *ev_int = indio_dev->event_interface;

	clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);

	iio_device_put(indio_dev);

	return 0;
}

static const struct file_operations iio_event_chrdev_fileops = {
	.read =  iio_event_chrdev_read,
	.poll =  iio_event_poll,
	.release = iio_event_chrdev_release,
	.owner = THIS_MODULE,
	.llseek = noop_llseek,
};

int iio_event_getfd(struct iio_dev *indio_dev)
{
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	int fd;

	if (ev_int == NULL)
		return -ENODEV;

	fd = mutex_lock_interruptible(&indio_dev->mlock);
	if (fd)
		return fd;

	if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
		fd = -EBUSY;
		goto unlock;
	}

	iio_device_get(indio_dev);

	fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
				indio_dev, O_RDONLY | O_CLOEXEC);
	if (fd < 0) {
		clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
		iio_device_put(indio_dev);
	} else {
		kfifo_reset_out(&ev_int->det_events);
	}

unlock:
	mutex_unlock(&indio_dev->mlock);
	return fd;
}

static const char * const iio_ev_type_text[] = {
	[IIO_EV_TYPE_THRESH] = "thresh",
	[IIO_EV_TYPE_MAG] = "mag",
	[IIO_EV_TYPE_ROC] = "roc",
	[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
	[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
	[IIO_EV_TYPE_CHANGE] = "change",
};

static const char * const iio_ev_dir_text[] = {
	[IIO_EV_DIR_EITHER] = "either",
	[IIO_EV_DIR_RISING] = "rising",
	[IIO_EV_DIR_FALLING] = "falling"
};

static const char * const iio_ev_info_text[] = {
	[IIO_EV_INFO_ENABLE] = "en",
	[IIO_EV_INFO_VALUE] = "value",
	[IIO_EV_INFO_HYSTERESIS] = "hysteresis",
	[IIO_EV_INFO_PERIOD] = "period",
	[IIO_EV_INFO_HIGH_PASS_FILTER_3DB] = "high_pass_filter_3db",
	[IIO_EV_INFO_LOW_PASS_FILTER_3DB] = "low_pass_filter_3db",
};

static enum iio_event_direction iio_ev_attr_dir(struct iio_dev_attr *attr)
{
	return attr->c->event_spec[attr->address & 0xffff].dir;
}

static enum iio_event_type iio_ev_attr_type(struct iio_dev_attr *attr)
{
	return attr->c->event_spec[attr->address & 0xffff].type;
}

static enum iio_event_info iio_ev_attr_info(struct iio_dev_attr *attr)
{
	return (attr->address >> 16) & 0xffff;
}

static ssize_t iio_ev_state_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf,
				  size_t len)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int ret;
	bool val;

	ret = strtobool(buf, &val);
	if (ret < 0)
		return ret;

	ret = indio_dev->info->write_event_config(indio_dev,
		this_attr->c, iio_ev_attr_type(this_attr),
		iio_ev_attr_dir(this_attr), val);

	return (ret < 0) ? ret : len;
}

static ssize_t iio_ev_state_show(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int val;

	val = indio_dev->info->read_event_config(indio_dev,
		this_attr->c, iio_ev_attr_type(this_attr),
		iio_ev_attr_dir(this_attr));
	if (val < 0)
		return val;
	else
		return sprintf(buf, "%d\n", val);
}

static ssize_t iio_ev_value_show(struct device *dev,
				 struct device_attribute *attr,
				 char *buf)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int val, val2, val_arr[2];
	int ret;

	ret = indio_dev->info->read_event_value(indio_dev,
		this_attr->c, iio_ev_attr_type(this_attr),
		iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
		&val, &val2);
	if (ret < 0)
		return ret;
	val_arr[0] = val;
	val_arr[1] = val2;
	return iio_format_value(buf, ret, 2, val_arr);
}

static ssize_t iio_ev_value_store(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf,
				  size_t len)
{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	int val, val2;
	int ret;

	if (!indio_dev->info->write_event_value)
		return -EINVAL;

	ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
	if (ret)
		return ret;
	ret = indio_dev->info->write_event_value(indio_dev,
		this_attr->c, iio_ev_attr_type(this_attr),
		iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
		val, val2);
	if (ret < 0)
		return ret;

	return len;
}

static int iio_device_add_event(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan, unsigned int spec_index,
	enum iio_event_type type, enum iio_event_direction dir,
	enum iio_shared_by shared_by, const unsigned long *mask)
{
	ssize_t (*show)(struct device *, struct device_attribute *, char *);
	ssize_t (*store)(struct device *, struct device_attribute *,
		const char *, size_t);
	unsigned int attrcount = 0;
	unsigned int i;
	char *postfix;
	int ret;

	for_each_set_bit(i, mask, sizeof(*mask)*8) {
		if (i >= ARRAY_SIZE(iio_ev_info_text))
			return -EINVAL;
		if (dir != IIO_EV_DIR_NONE)
			postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
					iio_ev_type_text[type],
					iio_ev_dir_text[dir],
					iio_ev_info_text[i]);
		else
			postfix = kasprintf(GFP_KERNEL, "%s_%s",
					iio_ev_type_text[type],
					iio_ev_info_text[i]);
		if (postfix == NULL)
			return -ENOMEM;

		if (i == IIO_EV_INFO_ENABLE) {
			show = iio_ev_state_show;
			store = iio_ev_state_store;
		} else {
			show = iio_ev_value_show;
			store = iio_ev_value_store;
		}

		ret = __iio_add_chan_devattr(postfix, chan, show, store,
			 (i << 16) | spec_index, shared_by, &indio_dev->dev,
			&indio_dev->event_interface->dev_attr_list);
		kfree(postfix);

		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
			continue;

		if (ret)
			return ret;

		attrcount++;
	}

	return attrcount;
}

static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan)
{
	int ret = 0, i, attrcount = 0;
	enum iio_event_direction dir;
	enum iio_event_type type;

	for (i = 0; i < chan->num_event_specs; i++) {
		type = chan->event_spec[i].type;
		dir = chan->event_spec[i].dir;

		ret = iio_device_add_event(indio_dev, chan, i, type, dir,
			IIO_SEPARATE, &chan->event_spec[i].mask_separate);
		if (ret < 0)
			return ret;
		attrcount += ret;

		ret = iio_device_add_event(indio_dev, chan, i, type, dir,
			IIO_SHARED_BY_TYPE,
			&chan->event_spec[i].mask_shared_by_type);
		if (ret < 0)
			return ret;
		attrcount += ret;

		ret = iio_device_add_event(indio_dev, chan, i, type, dir,
			IIO_SHARED_BY_DIR,
			&chan->event_spec[i].mask_shared_by_dir);
		if (ret < 0)
			return ret;
		attrcount += ret;

		ret = iio_device_add_event(indio_dev, chan, i, type, dir,
			IIO_SHARED_BY_ALL,
			&chan->event_spec[i].mask_shared_by_all);
		if (ret < 0)
			return ret;
		attrcount += ret;
	}
	ret = attrcount;
	return ret;
}

static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
{
	int j, ret, attrcount = 0;

	/* Dynamically created from the channels array */
	for (j = 0; j < indio_dev->num_channels; j++) {
		ret = iio_device_add_event_sysfs(indio_dev,
						 &indio_dev->channels[j]);
		if (ret < 0)
			return ret;
		attrcount += ret;
	}
	return attrcount;
}

static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
{
	int j;

	for (j = 0; j < indio_dev->num_channels; j++) {
		if (indio_dev->channels[j].num_event_specs != 0)
			return true;
	}
	return false;
}

static void iio_setup_ev_int(struct iio_event_interface *ev_int)
{
	INIT_KFIFO(ev_int->det_events);
	init_waitqueue_head(&ev_int->wait);
	mutex_init(&ev_int->read_lock);
}

static const char *iio_event_group_name = "events";
int iio_device_register_eventset(struct iio_dev *indio_dev)
{
	struct iio_dev_attr *p;
	int ret = 0, attrcount_orig = 0, attrcount, attrn;
	struct attribute **attr;

	if (!(indio_dev->info->event_attrs ||
	      iio_check_for_dynamic_events(indio_dev)))
		return 0;

	indio_dev->event_interface =
		kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
	if (indio_dev->event_interface == NULL)
		return -ENOMEM;

	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);

	iio_setup_ev_int(indio_dev->event_interface);
	if (indio_dev->info->event_attrs != NULL) {
		attr = indio_dev->info->event_attrs->attrs;
		while (*attr++ != NULL)
			attrcount_orig++;
	}
	attrcount = attrcount_orig;
	if (indio_dev->channels) {
		ret = __iio_add_event_config_attrs(indio_dev);
		if (ret < 0)
			goto error_free_setup_event_lines;
		attrcount += ret;
	}

	indio_dev->event_interface->group.name = iio_event_group_name;
	indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
							  sizeof(indio_dev->event_interface->group.attrs[0]),
							  GFP_KERNEL);
	if (indio_dev->event_interface->group.attrs == NULL) {
		ret = -ENOMEM;
		goto error_free_setup_event_lines;
	}
	if (indio_dev->info->event_attrs)
		memcpy(indio_dev->event_interface->group.attrs,
		       indio_dev->info->event_attrs->attrs,
		       sizeof(indio_dev->event_interface->group.attrs[0])
		       *attrcount_orig);
	attrn = attrcount_orig;
	/* Add all elements from the list. */
	list_for_each_entry(p,
			    &indio_dev->event_interface->dev_attr_list,
			    l)
		indio_dev->event_interface->group.attrs[attrn++] =
			&p->dev_attr.attr;
	indio_dev->groups[indio_dev->groupcounter++] =
		&indio_dev->event_interface->group;

	return 0;

error_free_setup_event_lines:
	iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
	kfree(indio_dev->event_interface);
	indio_dev->event_interface = NULL;
	return ret;
}

/**
 * iio_device_wakeup_eventset - Wakes up the event waitqueue
 * @indio_dev: The IIO device
 *
 * Wakes up the event waitqueue used for poll() and blocking read().
 * Should usually be called when the device is unregistered.
 */
void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
{
	if (indio_dev->event_interface == NULL)
		return;
	wake_up(&indio_dev->event_interface->wait);
}

void iio_device_unregister_eventset(struct iio_dev *indio_dev)
{
	if (indio_dev->event_interface == NULL)
		return;
	iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
	kfree(indio_dev->event_interface->group.attrs);
	kfree(indio_dev->event_interface);
}
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
0a769a95 LPC	2	/* Industrial I/O event handling
	3	*
	4	* Copyright (c) 2008 Jonathan Cameron
	5	*
0a769a95 LPC	6	* Based on elements of hwmon and input subsystems.
	7	*/
	8
	9	#include <linux/anon_inodes.h>
	10	#include <linux/device.h>
	11	#include <linux/fs.h>
	12	#include <linux/kernel.h>
2c00193f	13	#include <linux/kfifo.h>
0a769a95	14	#include <linux/module.h>
e18045ed	15	#include <linux/poll.h>
0a769a95 LPC	16	#include <linux/sched.h>
	17	#include <linux/slab.h>
	18	#include <linux/uaccess.h>
	19	#include <linux/wait.h>
06458e27	20	#include <linux/iio/iio.h>
0a769a95	21	#include "iio_core.h"
06458e27 JC	22	#include <linux/iio/sysfs.h>
06458e27 JC	23	#include <linux/iio/events.h>
0a769a95	24
0a769a95 LPC	25	/**
	26	* struct iio_event_interface - chrdev interface for an event line
	27	* @wait: wait queue to allow blocking reads of events
0a769a95	28	* @det_events: list of detected events
0a769a95 LPC	29	* @dev_attr_list: list of event interface sysfs attribute
	30	* @flags: file operations related flags including busy flag.
	31	* @group: event interface sysfs attribute group
a316c01d	32	* @read_lock: lock to protect kfifo read operations
0a769a95 LPC	33	*/
	34	struct iio_event_interface {
	35	wait_queue_head_t wait;
2c00193f LPC	36	DECLARE_KFIFO(det_events, struct iio_event_data, 16);
2c00193f LPC	37
0a769a95 LPC	38	struct list_head dev_attr_list;
	39	unsigned long flags;
	40	struct attribute_group group;
b91accaf	41	struct mutex read_lock;
0a769a95 LPC	42	};
0a769a95 LPC	43
bc2b7dab GB	44	bool iio_event_enabled(const struct iio_event_interface *ev_int)
	45	{
	46	return !!test_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
	47	}
	48
a7e57dce SK	49	/**
	50	* iio_push_event() - try to add event to the list for userspace reading
	51	* @indio_dev: IIO device structure
	52	* @ev_code: What event
	53	* @timestamp: When the event occurred
b91accaf LPC	54	*
	55	* Note: The caller must make sure that this function is not running
	56	* concurrently for the same indio_dev more than once.
4b1a9380 LPC	57	*
	58	* This function may be safely used as soon as a valid reference to iio_dev has
	59	* been obtained via iio_device_alloc(), but any events that are submitted
	60	* before iio_device_register() has successfully completed will be silently
	61	* discarded.
a7e57dce	62	**/
0a769a95 LPC	63	int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
	64	{
	65	struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f LPC	66	struct iio_event_data ev;
2c00193f LPC	67	int copied;
0a769a95	68
4b1a9380 LPC	69	if (!ev_int)
	70	return 0;
	71
0a769a95	72	/* Does anyone care? */
bc2b7dab	73	if (iio_event_enabled(ev_int)) {
0a769a95	74
2c00193f LPC	75	ev.id = ev_code;
	76	ev.timestamp = timestamp;
	77
498d319b	78	copied = kfifo_put(&ev_int->det_events, ev);
2c00193f	79	if (copied != 0)
a9a08845	80	wake_up_poll(&ev_int->wait, EPOLLIN);
43ba1100	81	}
0a769a95	82
2c00193f	83	return 0;
0a769a95 LPC	84	}
	85	EXPORT_SYMBOL(iio_push_event);
	86
e18045ed LPC	87	/**
e18045ed LPC	88	* iio_event_poll() - poll the event queue to find out if it has data
a316c01d CO	89	* @filep: File structure pointer to identify the device
	90	* @wait: Poll table pointer to add the wait queue on
	91	*
a9a08845	92	* Return: (EPOLLIN \| EPOLLRDNORM) if data is available for reading
a316c01d	93	* or a negative error code on failure
e18045ed	94	*/
afc9a42b	95	static __poll_t iio_event_poll(struct file *filep,
e18045ed LPC	96	struct poll_table_struct *wait)
e18045ed LPC	97	{
cadc2125 LPC	98	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	99	struct iio_event_interface *ev_int = indio_dev->event_interface;
afc9a42b	100	__poll_t events = 0;
e18045ed	101
f18e7a06	102	if (!indio_dev->info)
41d903c0	103	return events;
f18e7a06	104
e18045ed LPC	105	poll_wait(filep, &ev_int->wait, wait);
e18045ed LPC	106
e18045ed	107	if (!kfifo_is_empty(&ev_int->det_events))
a9a08845	108	events = EPOLLIN \| EPOLLRDNORM;
e18045ed LPC	109
	110	return events;
	111	}
	112
0a769a95 LPC	113	static ssize_t iio_event_chrdev_read(struct file *filep,
	114	char __user *buf,
	115	size_t count,
	116	loff_t *f_ps)
	117	{
cadc2125 LPC	118	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	119	struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f	120	unsigned int copied;
0a769a95 LPC	121	int ret;
0a769a95 LPC	122
f18e7a06 LPC	123	if (!indio_dev->info)
	124	return -ENODEV;
	125
2c00193f	126	if (count < sizeof(struct iio_event_data))
0a769a95 LPC	127	return -EINVAL;
0a769a95 LPC	128
b91accaf LPC	129	do {
	130	if (kfifo_is_empty(&ev_int->det_events)) {
	131	if (filep->f_flags & O_NONBLOCK)
	132	return -EAGAIN;
	133
	134	ret = wait_event_interruptible(ev_int->wait,
d2f0a48f LPC	135	!kfifo_is_empty(&ev_int->det_events) \|\|
d2f0a48f LPC	136	indio_dev->info == NULL);
b91accaf LPC	137	if (ret)
	138	return ret;
	139	if (indio_dev->info == NULL)
	140	return -ENODEV;
d2f0a48f	141	}
0a769a95	142
b91accaf LPC	143	if (mutex_lock_interruptible(&ev_int->read_lock))
	144	return -ERESTARTSYS;
	145	ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
	146	mutex_unlock(&ev_int->read_lock);
	147
	148	if (ret)
	149	return ret;
	150
	151	/*
	152	* If we couldn't read anything from the fifo (a different
	153	* thread might have been faster) we either return -EAGAIN if
	154	* the file descriptor is non-blocking, otherwise we go back to
	155	* sleep and wait for more data to arrive.
	156	*/
	157	if (copied == 0 && (filep->f_flags & O_NONBLOCK))
	158	return -EAGAIN;
0a769a95	159
b91accaf	160	} while (copied == 0);
43ba1100	161
b91accaf	162	return copied;
0a769a95 LPC	163	}
	164
	165	static int iio_event_chrdev_release(struct inode inode, struct file filep)
	166	{
cadc2125 LPC	167	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	168	struct iio_event_interface *ev_int = indio_dev->event_interface;
0a769a95	169
b91accaf	170	clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
0a769a95	171
cadc2125 LPC	172	iio_device_put(indio_dev);
cadc2125 LPC	173
0a769a95 LPC	174	return 0;
	175	}
	176
	177	static const struct file_operations iio_event_chrdev_fileops = {
	178	.read = iio_event_chrdev_read,
e18045ed	179	.poll = iio_event_poll,
0a769a95 LPC	180	.release = iio_event_chrdev_release,
	181	.owner = THIS_MODULE,
	182	.llseek = noop_llseek,
	183	};
	184
	185	int iio_event_getfd(struct iio_dev *indio_dev)
	186	{
	187	struct iio_event_interface *ev_int = indio_dev->event_interface;
	188	int fd;
	189
	190	if (ev_int == NULL)
	191	return -ENODEV;
	192
bc2b7dab GB	193	fd = mutex_lock_interruptible(&indio_dev->mlock);
	194	if (fd)
	195	return fd;
	196
	197	if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
	198	fd = -EBUSY;
	199	goto unlock;
	200	}
b91accaf	201
cadc2125 LPC	202	iio_device_get(indio_dev);
	203
	204	fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
e2aad1d5	205	indio_dev, O_RDONLY \| O_CLOEXEC);
0a769a95	206	if (fd < 0) {
b91accaf	207	clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
cadc2125	208	iio_device_put(indio_dev);
b91accaf LPC	209	} else {
b91accaf LPC	210	kfifo_reset_out(&ev_int->det_events);
0a769a95	211	}
b91accaf	212
bc2b7dab GB	213	unlock:
bc2b7dab GB	214	mutex_unlock(&indio_dev->mlock);
0a769a95 LPC	215	return fd;
	216	}
	217
	218	static const char * const iio_ev_type_text[] = {
	219	[IIO_EV_TYPE_THRESH] = "thresh",
	220	[IIO_EV_TYPE_MAG] = "mag",
	221	[IIO_EV_TYPE_ROC] = "roc",
	222	[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
	223	[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
27be8423	224	[IIO_EV_TYPE_CHANGE] = "change",
0a769a95 LPC	225	};
	226
	227	static const char * const iio_ev_dir_text[] = {
	228	[IIO_EV_DIR_EITHER] = "either",
	229	[IIO_EV_DIR_RISING] = "rising",
	230	[IIO_EV_DIR_FALLING] = "falling"
	231	};
	232
b4e3ac0a LPC	233	static const char * const iio_ev_info_text[] = {
	234	[IIO_EV_INFO_ENABLE] = "en",
	235	[IIO_EV_INFO_VALUE] = "value",
ec6670ae	236	[IIO_EV_INFO_HYSTERESIS] = "hysteresis",
77a533c7	237	[IIO_EV_INFO_PERIOD] = "period",
3f7f642b MF	238	[IIO_EV_INFO_HIGH_PASS_FILTER_3DB] = "high_pass_filter_3db",
3f7f642b MF	239	[IIO_EV_INFO_LOW_PASS_FILTER_3DB] = "low_pass_filter_3db",
b4e3ac0a LPC	240	};
	241
	242	static enum iio_event_direction iio_ev_attr_dir(struct iio_dev_attr *attr)
	243	{
	244	return attr->c->event_spec[attr->address & 0xffff].dir;
	245	}
	246
	247	static enum iio_event_type iio_ev_attr_type(struct iio_dev_attr *attr)
	248	{
	249	return attr->c->event_spec[attr->address & 0xffff].type;
	250	}
	251
	252	static enum iio_event_info iio_ev_attr_info(struct iio_dev_attr *attr)
	253	{
	254	return (attr->address >> 16) & 0xffff;
	255	}
	256
0a769a95 LPC	257	static ssize_t iio_ev_state_store(struct device *dev,
	258	struct device_attribute *attr,
	259	const char *buf,
	260	size_t len)
	261	{
e53f5ac5	262	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	263	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	264	int ret;
	265	bool val;
	266
	267	ret = strtobool(buf, &val);
	268	if (ret < 0)
	269	return ret;
	270
cb955852 LPC	271	ret = indio_dev->info->write_event_config(indio_dev,
	272	this_attr->c, iio_ev_attr_type(this_attr),
	273	iio_ev_attr_dir(this_attr), val);
b4e3ac0a	274
0a769a95 LPC	275	return (ret < 0) ? ret : len;
	276	}
	277
	278	static ssize_t iio_ev_state_show(struct device *dev,
	279	struct device_attribute *attr,
	280	char *buf)
	281	{
e53f5ac5	282	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	283	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
b4e3ac0a	284	int val;
0a769a95	285
cb955852 LPC	286	val = indio_dev->info->read_event_config(indio_dev,
	287	this_attr->c, iio_ev_attr_type(this_attr),
	288	iio_ev_attr_dir(this_attr));
0a769a95 LPC	289	if (val < 0)
	290	return val;
	291	else
	292	return sprintf(buf, "%d\n", val);
	293	}
	294
	295	static ssize_t iio_ev_value_show(struct device *dev,
	296	struct device_attribute *attr,
	297	char *buf)
	298	{
e53f5ac5	299	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	300	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
9fbfb4b3	301	int val, val2, val_arr[2];
b4e3ac0a	302	int ret;
0a769a95	303
cb955852 LPC	304	ret = indio_dev->info->read_event_value(indio_dev,
	305	this_attr->c, iio_ev_attr_type(this_attr),
	306	iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
	307	&val, &val2);
	308	if (ret < 0)
	309	return ret;
9fbfb4b3 SP	310	val_arr[0] = val;
	311	val_arr[1] = val2;
	312	return iio_format_value(buf, ret, 2, val_arr);
0a769a95 LPC	313	}
	314
	315	static ssize_t iio_ev_value_store(struct device *dev,
	316	struct device_attribute *attr,
	317	const char *buf,
	318	size_t len)
	319	{
e53f5ac5	320	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	321	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
b4e3ac0a	322	int val, val2;
0a769a95 LPC	323	int ret;
0a769a95 LPC	324
cb955852	325	if (!indio_dev->info->write_event_value)
0a769a95 LPC	326	return -EINVAL;
0a769a95 LPC	327
cb955852 LPC	328	ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
	329	if (ret)
	330	return ret;
	331	ret = indio_dev->info->write_event_value(indio_dev,
	332	this_attr->c, iio_ev_attr_type(this_attr),
	333	iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
	334	val, val2);
0a769a95 LPC	335	if (ret < 0)
	336	return ret;
	337
	338	return len;
	339	}
	340
b4e3ac0a LPC	341	static int iio_device_add_event(struct iio_dev *indio_dev,
	342	const struct iio_chan_spec *chan, unsigned int spec_index,
	343	enum iio_event_type type, enum iio_event_direction dir,
	344	enum iio_shared_by shared_by, const unsigned long *mask)
	345	{
	346	ssize_t (show)(struct device , struct device_attribute , char );
	347	ssize_t (store)(struct device , struct device_attribute *,
	348	const char *, size_t);
	349	unsigned int attrcount = 0;
	350	unsigned int i;
	351	char *postfix;
	352	int ret;
	353
ef4b4856 JC	354	for_each_set_bit(i, mask, sizeof(mask)8) {
	355	if (i >= ARRAY_SIZE(iio_ev_info_text))
	356	return -EINVAL;
1843c2f3 IT	357	if (dir != IIO_EV_DIR_NONE)
	358	postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
	359	iio_ev_type_text[type],
	360	iio_ev_dir_text[dir],
	361	iio_ev_info_text[i]);
	362	else
	363	postfix = kasprintf(GFP_KERNEL, "%s_%s",
	364	iio_ev_type_text[type],
	365	iio_ev_info_text[i]);
b4e3ac0a LPC	366	if (postfix == NULL)
	367	return -ENOMEM;
	368
	369	if (i == IIO_EV_INFO_ENABLE) {
	370	show = iio_ev_state_show;
	371	store = iio_ev_state_store;
	372	} else {
	373	show = iio_ev_value_show;
	374	store = iio_ev_value_store;
	375	}
	376
	377	ret = __iio_add_chan_devattr(postfix, chan, show, store,
	378	(i << 16) \| spec_index, shared_by, &indio_dev->dev,
	379	&indio_dev->event_interface->dev_attr_list);
	380	kfree(postfix);
	381
78b33216 SP	382	if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
	383	continue;
	384
b4e3ac0a LPC	385	if (ret)
	386	return ret;
	387
	388	attrcount++;
	389	}
	390
	391	return attrcount;
	392	}
	393
cb955852	394	static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
b4e3ac0a LPC	395	struct iio_chan_spec const *chan)
	396	{
	397	int ret = 0, i, attrcount = 0;
	398	enum iio_event_direction dir;
	399	enum iio_event_type type;
	400
	401	for (i = 0; i < chan->num_event_specs; i++) {
	402	type = chan->event_spec[i].type;
	403	dir = chan->event_spec[i].dir;
	404
	405	ret = iio_device_add_event(indio_dev, chan, i, type, dir,
	406	IIO_SEPARATE, &chan->event_spec[i].mask_separate);
	407	if (ret < 0)
92825ff9	408	return ret;
b4e3ac0a LPC	409	attrcount += ret;
	410
	411	ret = iio_device_add_event(indio_dev, chan, i, type, dir,
	412	IIO_SHARED_BY_TYPE,
	413	&chan->event_spec[i].mask_shared_by_type);
	414	if (ret < 0)
92825ff9	415	return ret;
b4e3ac0a LPC	416	attrcount += ret;
	417
	418	ret = iio_device_add_event(indio_dev, chan, i, type, dir,
	419	IIO_SHARED_BY_DIR,
	420	&chan->event_spec[i].mask_shared_by_dir);
	421	if (ret < 0)
92825ff9	422	return ret;
b4e3ac0a LPC	423	attrcount += ret;
	424
	425	ret = iio_device_add_event(indio_dev, chan, i, type, dir,
	426	IIO_SHARED_BY_ALL,
	427	&chan->event_spec[i].mask_shared_by_all);
	428	if (ret < 0)
92825ff9	429	return ret;
b4e3ac0a LPC	430	attrcount += ret;
	431	}
	432	ret = attrcount;
b4e3ac0a LPC	433	return ret;
	434	}
	435
0a769a95 LPC	436	static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
	437	{
	438	int j, ret, attrcount = 0;
	439
2179aabe	440	/* Dynamically created from the channels array */
0a769a95 LPC	441	for (j = 0; j < indio_dev->num_channels; j++) {
	442	ret = iio_device_add_event_sysfs(indio_dev,
	443	&indio_dev->channels[j]);
	444	if (ret < 0)
e3db9ef6	445	return ret;
0a769a95 LPC	446	attrcount += ret;
	447	}
	448	return attrcount;
0a769a95 LPC	449	}
	450
	451	static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
	452	{
	453	int j;
	454
b4e3ac0a	455	for (j = 0; j < indio_dev->num_channels; j++) {
b4e3ac0a LPC	456	if (indio_dev->channels[j].num_event_specs != 0)
	457	return true;
	458	}
0a769a95 LPC	459	return false;
	460	}
	461
	462	static void iio_setup_ev_int(struct iio_event_interface *ev_int)
	463	{
2c00193f	464	INIT_KFIFO(ev_int->det_events);
0a769a95	465	init_waitqueue_head(&ev_int->wait);
b91accaf	466	mutex_init(&ev_int->read_lock);
0a769a95 LPC	467	}
	468
	469	static const char *iio_event_group_name = "events";
	470	int iio_device_register_eventset(struct iio_dev *indio_dev)
	471	{
	472	struct iio_dev_attr *p;
	473	int ret = 0, attrcount_orig = 0, attrcount, attrn;
	474	struct attribute **attr;
	475
	476	if (!(indio_dev->info->event_attrs \|\|
	477	iio_check_for_dynamic_events(indio_dev)))
	478	return 0;
	479
	480	indio_dev->event_interface =
	481	kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
92825ff9 HK	482	if (indio_dev->event_interface == NULL)
92825ff9 HK	483	return -ENOMEM;
0a769a95	484
46b24311 SH	485	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
46b24311 SH	486
0a769a95 LPC	487	iio_setup_ev_int(indio_dev->event_interface);
	488	if (indio_dev->info->event_attrs != NULL) {
	489	attr = indio_dev->info->event_attrs->attrs;
	490	while (*attr++ != NULL)
	491	attrcount_orig++;
	492	}
	493	attrcount = attrcount_orig;
	494	if (indio_dev->channels) {
	495	ret = __iio_add_event_config_attrs(indio_dev);
	496	if (ret < 0)
	497	goto error_free_setup_event_lines;
	498	attrcount += ret;
	499	}
	500
	501	indio_dev->event_interface->group.name = iio_event_group_name;
	502	indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
	503	sizeof(indio_dev->event_interface->group.attrs[0]),
	504	GFP_KERNEL);
	505	if (indio_dev->event_interface->group.attrs == NULL) {
	506	ret = -ENOMEM;
	507	goto error_free_setup_event_lines;
	508	}
	509	if (indio_dev->info->event_attrs)
	510	memcpy(indio_dev->event_interface->group.attrs,
	511	indio_dev->info->event_attrs->attrs,
	512	sizeof(indio_dev->event_interface->group.attrs[0])
	513	*attrcount_orig);
	514	attrn = attrcount_orig;
	515	/* Add all elements from the list. */
	516	list_for_each_entry(p,
	517	&indio_dev->event_interface->dev_attr_list,
	518	l)
	519	indio_dev->event_interface->group.attrs[attrn++] =
	520	&p->dev_attr.attr;
	521	indio_dev->groups[indio_dev->groupcounter++] =
	522	&indio_dev->event_interface->group;
	523
	524	return 0;
	525
	526	error_free_setup_event_lines:
84088ebd	527	iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
0a769a95	528	kfree(indio_dev->event_interface);
c1b03ab5	529	indio_dev->event_interface = NULL;
0a769a95 LPC	530	return ret;
	531	}
	532
d2f0a48f LPC	533	/**
	534	* iio_device_wakeup_eventset - Wakes up the event waitqueue
	535	* @indio_dev: The IIO device
	536	*
	537	* Wakes up the event waitqueue used for poll() and blocking read().
	538	* Should usually be called when the device is unregistered.
	539	*/
	540	void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
	541	{
	542	if (indio_dev->event_interface == NULL)
	543	return;
	544	wake_up(&indio_dev->event_interface->wait);
	545	}
	546
0a769a95 LPC	547	void iio_device_unregister_eventset(struct iio_dev *indio_dev)
	548	{
	549	if (indio_dev->event_interface == NULL)
	550	return;
84088ebd	551	iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
0a769a95 LPC	552	kfree(indio_dev->event_interface->group.attrs);
	553	kfree(indio_dev->event_interface);
	554	}