[deliverable/linux.git] / drivers / staging / 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/sched.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include "iio.h"
#include "iio_core.h"
#include "sysfs.h"
#include "events.h"

/**
 * struct iio_event_interface - chrdev interface for an event line
 * @wait:		wait queue to allow blocking reads of events
 * @event_list_lock:	mutex to protect the list of detected 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(&ev_int->wait);
	}
	spin_unlock(&ev_int->wait.lock);

	return 0;
}
EXPORT_SYMBOL(iio_push_event);

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,
	.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_get_drvdata(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_get_drvdata(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_get_drvdata(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_get_drvdata(dev);
	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	unsigned long val;
	int ret;

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

	ret = strict_strtoul(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;

	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
	/* 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)
			goto error_clear_attrs;
		attrcount += ret;
	}
	return attrcount;

error_clear_attrs:
	__iio_remove_event_config_attrs(indio_dev);

	return ret;
}

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;
	}

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