[mirror_ubuntu-zesty-kernel.git] / drivers / iio / industrialio-event.c

/* Industrial I/O event handling
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * 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.
 *
 * 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
 */
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;
};

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;

	/* Does anyone care? */
	spin_lock(&ev_int->wait.lock);
	if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {

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

		copied = kfifo_put(&ev_int->det_events, &ev);
		if (copied != 0)
			wake_up_locked_poll(&ev_int->wait, POLLIN);
	}
	spin_unlock(&ev_int->wait.lock);

	return 0;
}
EXPORT_SYMBOL(iio_push_event);

/**
 * iio_event_poll() - poll the event queue to find out if it has data
 */
static unsigned int iio_event_poll(struct file *filep,
			     struct poll_table_struct *wait)
{
	struct iio_event_interface *ev_int = filep->private_data;
	unsigned int events = 0;

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

	spin_lock(&ev_int->wait.lock);
	if (!kfifo_is_empty(&ev_int->det_events))
		events = POLLIN | POLLRDNORM;
	spin_unlock(&ev_int->wait.lock);

	return events;
}

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

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

	spin_lock(&ev_int->wait.lock);
	if (kfifo_is_empty(&ev_int->det_events)) {
		if (filep->f_flags & O_NONBLOCK) {
			ret = -EAGAIN;
			goto error_unlock;
		}
		/* Blocking on device; waiting for something to be there */
		ret = wait_event_interruptible_locked(ev_int->wait,
					!kfifo_is_empty(&ev_int->det_events));
		if (ret)
			goto error_unlock;
		/* Single access device so no one else can get the data */
	}

	ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);

error_unlock:
	spin_unlock(&ev_int->wait.lock);

	return ret ? ret : copied;
}

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

	spin_lock(&ev_int->wait.lock);
	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
	/*
	 * In order to maintain a clean state for reopening,
	 * clear out any awaiting events. The mask will prevent
	 * any new __iio_push_event calls running.
	 */
	kfifo_reset_out(&ev_int->det_events);
	spin_unlock(&ev_int->wait.lock);

	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;

	spin_lock(&ev_int->wait.lock);
	if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
		spin_unlock(&ev_int->wait.lock);
		return -EBUSY;
	}
	spin_unlock(&ev_int->wait.lock);
	fd = anon_inode_getfd("iio:event",
				&iio_event_chrdev_fileops, ev_int, O_RDONLY);
	if (fd < 0) {
		spin_lock(&ev_int->wait.lock);
		__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
		spin_unlock(&ev_int->wait.lock);
	}
	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",
};

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

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->address,
						  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 = indio_dev->info->read_event_config(indio_dev,
						     this_attr->address);

	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, ret;

	ret = indio_dev->info->read_event_value(indio_dev,
						this_attr->address, &val);
	if (ret < 0)
		return ret;

	return sprintf(buf, "%d\n", val);
}

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;
	int ret;

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

	ret = kstrtoint(buf, 10, &val);
	if (ret)
		return ret;

	ret = indio_dev->info->write_event_value(indio_dev, this_attr->address,
						 val);
	if (ret < 0)
		return ret;

	return len;
}

static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
				      struct iio_chan_spec const *chan)
{
	int ret = 0, i, attrcount = 0;
	u64 mask = 0;
	char *postfix;
	if (!chan->event_mask)
		return 0;

	for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) {
		postfix = kasprintf(GFP_KERNEL, "%s_%s_en",
				    iio_ev_type_text[i/IIO_EV_DIR_MAX],
				    iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
		if (postfix == NULL) {
			ret = -ENOMEM;
			goto error_ret;
		}
		if (chan->modified)
			mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel,
						  i/IIO_EV_DIR_MAX,
						  i%IIO_EV_DIR_MAX);
		else if (chan->differential)
			mask = IIO_EVENT_CODE(chan->type,
					      0, 0,
					      i%IIO_EV_DIR_MAX,
					      i/IIO_EV_DIR_MAX,
					      0,
					      chan->channel,
					      chan->channel2);
		else
			mask = IIO_UNMOD_EVENT_CODE(chan->type,
						    chan->channel,
						    i/IIO_EV_DIR_MAX,
						    i%IIO_EV_DIR_MAX);

		ret = __iio_add_chan_devattr(postfix,
					     chan,
					     &iio_ev_state_show,
					     iio_ev_state_store,
					     mask,
					     0,
					     &indio_dev->dev,
					     &indio_dev->event_interface->
					     dev_attr_list);
		kfree(postfix);
		if (ret)
			goto error_ret;
		attrcount++;
		postfix = kasprintf(GFP_KERNEL, "%s_%s_value",
				    iio_ev_type_text[i/IIO_EV_DIR_MAX],
				    iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
		if (postfix == NULL) {
			ret = -ENOMEM;
			goto error_ret;
		}
		ret = __iio_add_chan_devattr(postfix, chan,
					     iio_ev_value_show,
					     iio_ev_value_store,
					     mask,
					     0,
					     &indio_dev->dev,
					     &indio_dev->event_interface->
					     dev_attr_list);
		kfree(postfix);
		if (ret)
			goto error_ret;
		attrcount++;
	}
	ret = attrcount;
error_ret:
	return ret;
}

static inline void __iio_remove_event_config_attrs(struct iio_dev *indio_dev)
{
	struct iio_dev_attr *p, *n;
	list_for_each_entry_safe(p, n,
				 &indio_dev->event_interface->
				 dev_attr_list, l) {
		kfree(p->dev_attr.attr.name);
		kfree(p);
	}
}

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

	/* Dynically 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].event_mask != 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);
}

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) {
		ret = -ENOMEM;
		goto error_ret;
	}

	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_remove_event_config_attrs(indio_dev);
	kfree(indio_dev->event_interface);
error_ret:

	return ret;
}

void iio_device_unregister_eventset(struct iio_dev *indio_dev)
{
	if (indio_dev->event_interface == NULL)
		return;
	__iio_remove_event_config_attrs(indio_dev);
	kfree(indio_dev->event_interface->group.attrs);
	kfree(indio_dev->event_interface);
}
Commit	Line	Data
0a769a95 LPC	1	/* Industrial I/O event handling
	2	*
	3	* Copyright (c) 2008 Jonathan Cameron
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License version 2 as published by
	7	* the Free Software Foundation.
	8	*
	9	* Based on elements of hwmon and input subsystems.
	10	*/
	11
	12	#include <linux/anon_inodes.h>
	13	#include <linux/device.h>
	14	#include <linux/fs.h>
	15	#include <linux/kernel.h>
2c00193f	16	#include <linux/kfifo.h>
0a769a95	17	#include <linux/module.h>
e18045ed	18	#include <linux/poll.h>
0a769a95 LPC	19	#include <linux/sched.h>
	20	#include <linux/slab.h>
	21	#include <linux/uaccess.h>
	22	#include <linux/wait.h>
06458e27	23	#include <linux/iio/iio.h>
0a769a95	24	#include "iio_core.h"
06458e27 JC	25	#include <linux/iio/sysfs.h>
06458e27 JC	26	#include <linux/iio/events.h>
0a769a95	27
0a769a95 LPC	28	/**
	29	* struct iio_event_interface - chrdev interface for an event line
	30	* @wait: wait queue to allow blocking reads of events
0a769a95	31	* @det_events: list of detected events
0a769a95 LPC	32	* @dev_attr_list: list of event interface sysfs attribute
	33	* @flags: file operations related flags including busy flag.
	34	* @group: event interface sysfs attribute group
	35	*/
	36	struct iio_event_interface {
	37	wait_queue_head_t wait;
2c00193f LPC	38	DECLARE_KFIFO(det_events, struct iio_event_data, 16);
2c00193f LPC	39
0a769a95 LPC	40	struct list_head dev_attr_list;
	41	unsigned long flags;
	42	struct attribute_group group;
	43	};
	44
	45	int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
	46	{
	47	struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f LPC	48	struct iio_event_data ev;
2c00193f LPC	49	int copied;
0a769a95 LPC	50
0a769a95 LPC	51	/* Does anyone care? */
43ba1100	52	spin_lock(&ev_int->wait.lock);
0a769a95	53	if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
0a769a95	54
2c00193f LPC	55	ev.id = ev_code;
	56	ev.timestamp = timestamp;
	57
	58	copied = kfifo_put(&ev_int->det_events, &ev);
2c00193f	59	if (copied != 0)
e18045ed	60	wake_up_locked_poll(&ev_int->wait, POLLIN);
43ba1100 LPC	61	}
43ba1100 LPC	62	spin_unlock(&ev_int->wait.lock);
0a769a95	63
2c00193f	64	return 0;
0a769a95 LPC	65	}
	66	EXPORT_SYMBOL(iio_push_event);
	67
e18045ed LPC	68	/**
	69	* iio_event_poll() - poll the event queue to find out if it has data
	70	*/
	71	static unsigned int iio_event_poll(struct file *filep,
	72	struct poll_table_struct *wait)
	73	{
	74	struct iio_event_interface *ev_int = filep->private_data;
	75	unsigned int events = 0;
	76
	77	poll_wait(filep, &ev_int->wait, wait);
	78
	79	spin_lock(&ev_int->wait.lock);
	80	if (!kfifo_is_empty(&ev_int->det_events))
	81	events = POLLIN \| POLLRDNORM;
	82	spin_unlock(&ev_int->wait.lock);
	83
	84	return events;
	85	}
	86
0a769a95 LPC	87	static ssize_t iio_event_chrdev_read(struct file *filep,
	88	char __user *buf,
	89	size_t count,
	90	loff_t *f_ps)
	91	{
	92	struct iio_event_interface *ev_int = filep->private_data;
2c00193f	93	unsigned int copied;
0a769a95 LPC	94	int ret;
0a769a95 LPC	95
2c00193f	96	if (count < sizeof(struct iio_event_data))
0a769a95 LPC	97	return -EINVAL;
0a769a95 LPC	98
43ba1100	99	spin_lock(&ev_int->wait.lock);
2c00193f	100	if (kfifo_is_empty(&ev_int->det_events)) {
0a769a95 LPC	101	if (filep->f_flags & O_NONBLOCK) {
0a769a95 LPC	102	ret = -EAGAIN;
43ba1100	103	goto error_unlock;
0a769a95	104	}
0a769a95	105	/* Blocking on device; waiting for something to be there */
43ba1100	106	ret = wait_event_interruptible_locked(ev_int->wait,
2c00193f	107	!kfifo_is_empty(&ev_int->det_events));
0a769a95	108	if (ret)
43ba1100	109	goto error_unlock;
0a769a95	110	/* Single access device so no one else can get the data */
0a769a95 LPC	111	}
0a769a95 LPC	112
2c00193f	113	ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
0a769a95	114
43ba1100 LPC	115	error_unlock:
	116	spin_unlock(&ev_int->wait.lock);
	117
2c00193f	118	return ret ? ret : copied;
0a769a95 LPC	119	}
	120
	121	static int iio_event_chrdev_release(struct inode inode, struct file filep)
	122	{
	123	struct iio_event_interface *ev_int = filep->private_data;
0a769a95	124
43ba1100	125	spin_lock(&ev_int->wait.lock);
a046c1e8	126	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
0a769a95 LPC	127	/*
	128	* In order to maintain a clean state for reopening,
	129	* clear out any awaiting events. The mask will prevent
	130	* any new __iio_push_event calls running.
	131	*/
2c00193f	132	kfifo_reset_out(&ev_int->det_events);
43ba1100	133	spin_unlock(&ev_int->wait.lock);
0a769a95 LPC	134
	135	return 0;
	136	}
	137
	138	static const struct file_operations iio_event_chrdev_fileops = {
	139	.read = iio_event_chrdev_read,
e18045ed	140	.poll = iio_event_poll,
0a769a95 LPC	141	.release = iio_event_chrdev_release,
	142	.owner = THIS_MODULE,
	143	.llseek = noop_llseek,
	144	};
	145
	146	int iio_event_getfd(struct iio_dev *indio_dev)
	147	{
	148	struct iio_event_interface *ev_int = indio_dev->event_interface;
	149	int fd;
	150
	151	if (ev_int == NULL)
	152	return -ENODEV;
	153
43ba1100	154	spin_lock(&ev_int->wait.lock);
a046c1e8	155	if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
43ba1100	156	spin_unlock(&ev_int->wait.lock);
0a769a95 LPC	157	return -EBUSY;
0a769a95 LPC	158	}
43ba1100	159	spin_unlock(&ev_int->wait.lock);
0a769a95 LPC	160	fd = anon_inode_getfd("iio:event",
	161	&iio_event_chrdev_fileops, ev_int, O_RDONLY);
	162	if (fd < 0) {
43ba1100	163	spin_lock(&ev_int->wait.lock);
a046c1e8	164	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
43ba1100	165	spin_unlock(&ev_int->wait.lock);
0a769a95 LPC	166	}
	167	return fd;
	168	}
	169
	170	static const char * const iio_ev_type_text[] = {
	171	[IIO_EV_TYPE_THRESH] = "thresh",
	172	[IIO_EV_TYPE_MAG] = "mag",
	173	[IIO_EV_TYPE_ROC] = "roc",
	174	[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
	175	[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
	176	};
	177
	178	static const char * const iio_ev_dir_text[] = {
	179	[IIO_EV_DIR_EITHER] = "either",
	180	[IIO_EV_DIR_RISING] = "rising",
	181	[IIO_EV_DIR_FALLING] = "falling"
	182	};
	183
	184	static ssize_t iio_ev_state_store(struct device *dev,
	185	struct device_attribute *attr,
	186	const char *buf,
	187	size_t len)
	188	{
e53f5ac5	189	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	190	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	191	int ret;
	192	bool val;
	193
	194	ret = strtobool(buf, &val);
	195	if (ret < 0)
	196	return ret;
	197
	198	ret = indio_dev->info->write_event_config(indio_dev,
	199	this_attr->address,
	200	val);
	201	return (ret < 0) ? ret : len;
	202	}
	203
	204	static ssize_t iio_ev_state_show(struct device *dev,
	205	struct device_attribute *attr,
	206	char *buf)
	207	{
e53f5ac5	208	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	209	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	210	int val = indio_dev->info->read_event_config(indio_dev,
	211	this_attr->address);
	212
	213	if (val < 0)
	214	return val;
	215	else
	216	return sprintf(buf, "%d\n", val);
	217	}
	218
	219	static ssize_t iio_ev_value_show(struct device *dev,
	220	struct device_attribute *attr,
	221	char *buf)
	222	{
e53f5ac5	223	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	224	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	225	int val, ret;
	226
	227	ret = indio_dev->info->read_event_value(indio_dev,
	228	this_attr->address, &val);
	229	if (ret < 0)
	230	return ret;
	231
	232	return sprintf(buf, "%d\n", val);
	233	}
	234
	235	static ssize_t iio_ev_value_store(struct device *dev,
	236	struct device_attribute *attr,
	237	const char *buf,
	238	size_t len)
	239	{
e53f5ac5	240	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	241	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
948ad205	242	int val;
0a769a95 LPC	243	int ret;
	244
	245	if (!indio_dev->info->write_event_value)
	246	return -EINVAL;
	247
948ad205	248	ret = kstrtoint(buf, 10, &val);
0a769a95 LPC	249	if (ret)
	250	return ret;
	251
	252	ret = indio_dev->info->write_event_value(indio_dev, this_attr->address,
	253	val);
	254	if (ret < 0)
	255	return ret;
	256
	257	return len;
	258	}
	259
	260	static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
	261	struct iio_chan_spec const *chan)
	262	{
	263	int ret = 0, i, attrcount = 0;
	264	u64 mask = 0;
	265	char *postfix;
	266	if (!chan->event_mask)
	267	return 0;
	268
	269	for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) {
	270	postfix = kasprintf(GFP_KERNEL, "%s_%s_en",
	271	iio_ev_type_text[i/IIO_EV_DIR_MAX],
	272	iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
	273	if (postfix == NULL) {
	274	ret = -ENOMEM;
	275	goto error_ret;
	276	}
	277	if (chan->modified)
	278	mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel,
	279	i/IIO_EV_DIR_MAX,
	280	i%IIO_EV_DIR_MAX);
	281	else if (chan->differential)
	282	mask = IIO_EVENT_CODE(chan->type,
	283	0, 0,
	284	i%IIO_EV_DIR_MAX,
	285	i/IIO_EV_DIR_MAX,
	286	0,
	287	chan->channel,
	288	chan->channel2);
	289	else
	290	mask = IIO_UNMOD_EVENT_CODE(chan->type,
	291	chan->channel,
	292	i/IIO_EV_DIR_MAX,
	293	i%IIO_EV_DIR_MAX);
	294
	295	ret = __iio_add_chan_devattr(postfix,
	296	chan,
	297	&iio_ev_state_show,
	298	iio_ev_state_store,
	299	mask,
	300	0,
	301	&indio_dev->dev,
	302	&indio_dev->event_interface->
	303	dev_attr_list);
	304	kfree(postfix);
	305	if (ret)
	306	goto error_ret;
	307	attrcount++;
	308	postfix = kasprintf(GFP_KERNEL, "%s_%s_value",
	309	iio_ev_type_text[i/IIO_EV_DIR_MAX],
	310	iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
	311	if (postfix == NULL) {
	312	ret = -ENOMEM;
313	goto error_ret;
314	}
315	ret = __iio_add_chan_devattr(postfix, chan,
316	iio_ev_value_show,
317	iio_ev_value_store,
318	mask,
319	0,
320	&indio_dev->dev,
321	&indio_dev->event_interface->
322	dev_attr_list);
323	kfree(postfix);
324	if (ret)
325	goto error_ret;
326	attrcount++;
327	}
328	ret = attrcount;
329	error_ret:
330	return ret;
331	}
332
333	static inline void __iio_remove_event_config_attrs(struct iio_dev *indio_dev)
334	{
335	struct iio_dev_attr p, n;
336	list_for_each_entry_safe(p, n,
337	&indio_dev->event_interface->
338	dev_attr_list, l) {
339	kfree(p->dev_attr.attr.name);
340	kfree(p);
341	}
342	}
343
344	static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
345	{
346	int j, ret, attrcount = 0;
347
0a769a95 LPC	348	/* Dynically created from the channels array */
	349	for (j = 0; j < indio_dev->num_channels; j++) {
	350	ret = iio_device_add_event_sysfs(indio_dev,
	351	&indio_dev->channels[j]);
	352	if (ret < 0)
e3db9ef6	353	return ret;
0a769a95 LPC	354	attrcount += ret;
	355	}
	356	return attrcount;
0a769a95 LPC	357	}
	358
	359	static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
	360	{
	361	int j;
	362
	363	for (j = 0; j < indio_dev->num_channels; j++)
	364	if (indio_dev->channels[j].event_mask != 0)
	365	return true;
	366	return false;
	367	}
	368
	369	static void iio_setup_ev_int(struct iio_event_interface *ev_int)
	370	{
2c00193f	371	INIT_KFIFO(ev_int->det_events);
0a769a95 LPC	372	init_waitqueue_head(&ev_int->wait);
	373	}
	374
	375	static const char *iio_event_group_name = "events";
	376	int iio_device_register_eventset(struct iio_dev *indio_dev)
	377	{
	378	struct iio_dev_attr *p;
	379	int ret = 0, attrcount_orig = 0, attrcount, attrn;
	380	struct attribute **attr;
	381
	382	if (!(indio_dev->info->event_attrs \|\|
	383	iio_check_for_dynamic_events(indio_dev)))
	384	return 0;
	385
	386	indio_dev->event_interface =
	387	kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
	388	if (indio_dev->event_interface == NULL) {
	389	ret = -ENOMEM;
	390	goto error_ret;
	391	}
	392
46b24311 SH	393	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
46b24311 SH	394
0a769a95 LPC	395	iio_setup_ev_int(indio_dev->event_interface);
	396	if (indio_dev->info->event_attrs != NULL) {
	397	attr = indio_dev->info->event_attrs->attrs;
	398	while (*attr++ != NULL)
	399	attrcount_orig++;
	400	}
	401	attrcount = attrcount_orig;
	402	if (indio_dev->channels) {
	403	ret = __iio_add_event_config_attrs(indio_dev);
	404	if (ret < 0)
	405	goto error_free_setup_event_lines;
	406	attrcount += ret;
	407	}
	408
	409	indio_dev->event_interface->group.name = iio_event_group_name;
	410	indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
	411	sizeof(indio_dev->event_interface->group.attrs[0]),
	412	GFP_KERNEL);
	413	if (indio_dev->event_interface->group.attrs == NULL) {
	414	ret = -ENOMEM;
	415	goto error_free_setup_event_lines;
	416	}
	417	if (indio_dev->info->event_attrs)
	418	memcpy(indio_dev->event_interface->group.attrs,
	419	indio_dev->info->event_attrs->attrs,
	420	sizeof(indio_dev->event_interface->group.attrs[0])
	421	*attrcount_orig);
	422	attrn = attrcount_orig;
	423	/* Add all elements from the list. */
	424	list_for_each_entry(p,
	425	&indio_dev->event_interface->dev_attr_list,
	426	l)
	427	indio_dev->event_interface->group.attrs[attrn++] =
	428	&p->dev_attr.attr;
	429	indio_dev->groups[indio_dev->groupcounter++] =
	430	&indio_dev->event_interface->group;
	431
	432	return 0;
	433
	434	error_free_setup_event_lines:
	435	__iio_remove_event_config_attrs(indio_dev);
	436	kfree(indio_dev->event_interface);
	437	error_ret:
	438
	439	return ret;
	440	}
	441
	442	void iio_device_unregister_eventset(struct iio_dev *indio_dev)
	443	{
	444	if (indio_dev->event_interface == NULL)
	445	return;
	446	__iio_remove_event_config_attrs(indio_dev);
	447	kfree(indio_dev->event_interface->group.attrs);
	448	kfree(indio_dev->event_interface);
	449	}