[GitHub/mt8127/android_kernel_alcatel_ttab.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;
	struct mutex		read_lock;
	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;
	unsigned long flags;
	int copied;

	/* Does anyone care? */
	spin_lock_irqsave(&ev_int->wait.lock, flags);
	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_irqrestore(&ev_int->wait.lock, flags);

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

	if (mutex_lock_interruptible(&ev_int->read_lock))
		return -ERESTARTSYS;

	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(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:
	mutex_unlock(&ev_int->read_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_irq(&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_irq(&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_irq(&ev_int->wait.lock);
	if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
		spin_unlock_irq(&ev_int->wait.lock);
		return -EBUSY;
	}
	spin_unlock_irq(&ev_int->wait.lock);
	fd = anon_inode_getfd("iio:event",
				&iio_event_chrdev_fileops, ev_int, O_RDONLY);
	if (fd < 0) {
		spin_lock_irq(&ev_int->wait.lock);
		__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
		spin_unlock_irq(&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);
	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) {
		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);
	mutex_destroy(&indio_dev->event_interface->read_lock);
	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);
	mutex_destroy(&indio_dev->event_interface->read_lock);
	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;
6fa3eb70	38	struct mutex read_lock;
2c00193f LPC	39	DECLARE_KFIFO(det_events, struct iio_event_data, 16);
2c00193f LPC	40
0a769a95 LPC	41	struct list_head dev_attr_list;
	42	unsigned long flags;
	43	struct attribute_group group;
	44	};
	45
	46	int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
	47	{
	48	struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f	49	struct iio_event_data ev;
1b9dc91e	50	unsigned long flags;
2c00193f	51	int copied;
0a769a95 LPC	52
0a769a95 LPC	53	/* Does anyone care? */
1b9dc91e	54	spin_lock_irqsave(&ev_int->wait.lock, flags);
0a769a95	55	if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
0a769a95	56
2c00193f LPC	57	ev.id = ev_code;
	58	ev.timestamp = timestamp;
	59
	60	copied = kfifo_put(&ev_int->det_events, &ev);
2c00193f	61	if (copied != 0)
e18045ed	62	wake_up_locked_poll(&ev_int->wait, POLLIN);
43ba1100	63	}
1b9dc91e	64	spin_unlock_irqrestore(&ev_int->wait.lock, flags);
0a769a95	65
2c00193f	66	return 0;
0a769a95 LPC	67	}
	68	EXPORT_SYMBOL(iio_push_event);
	69
e18045ed LPC	70	/**
	71	* iio_event_poll() - poll the event queue to find out if it has data
	72	*/
	73	static unsigned int iio_event_poll(struct file *filep,
	74	struct poll_table_struct *wait)
	75	{
	76	struct iio_event_interface *ev_int = filep->private_data;
	77	unsigned int events = 0;
	78
	79	poll_wait(filep, &ev_int->wait, wait);
	80
1b9dc91e	81	spin_lock_irq(&ev_int->wait.lock);
e18045ed LPC	82	if (!kfifo_is_empty(&ev_int->det_events))
e18045ed LPC	83	events = POLLIN \| POLLRDNORM;
1b9dc91e	84	spin_unlock_irq(&ev_int->wait.lock);
e18045ed LPC	85
	86	return events;
	87	}
	88
0a769a95 LPC	89	static ssize_t iio_event_chrdev_read(struct file *filep,
	90	char __user *buf,
	91	size_t count,
	92	loff_t *f_ps)
	93	{
	94	struct iio_event_interface *ev_int = filep->private_data;
2c00193f	95	unsigned int copied;
0a769a95 LPC	96	int ret;
0a769a95 LPC	97
2c00193f	98	if (count < sizeof(struct iio_event_data))
0a769a95 LPC	99	return -EINVAL;
0a769a95 LPC	100
6fa3eb70 S	101	if (mutex_lock_interruptible(&ev_int->read_lock))
	102	return -ERESTARTSYS;
	103
2c00193f	104	if (kfifo_is_empty(&ev_int->det_events)) {
0a769a95 LPC	105	if (filep->f_flags & O_NONBLOCK) {
0a769a95 LPC	106	ret = -EAGAIN;
43ba1100	107	goto error_unlock;
0a769a95	108	}
0a769a95	109	/* Blocking on device; waiting for something to be there */
6fa3eb70	110	ret = wait_event_interruptible(ev_int->wait,
2c00193f	111	!kfifo_is_empty(&ev_int->det_events));
0a769a95	112	if (ret)
43ba1100	113	goto error_unlock;
0a769a95	114	/* Single access device so no one else can get the data */
0a769a95 LPC	115	}
0a769a95 LPC	116
2c00193f	117	ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
0a769a95	118
43ba1100	119	error_unlock:
6fa3eb70	120	mutex_unlock(&ev_int->read_lock);
43ba1100	121
2c00193f	122	return ret ? ret : copied;
0a769a95 LPC	123	}
	124
	125	static int iio_event_chrdev_release(struct inode inode, struct file filep)
	126	{
	127	struct iio_event_interface *ev_int = filep->private_data;
0a769a95	128
1b9dc91e	129	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	130	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
0a769a95 LPC	131	/*
	132	* In order to maintain a clean state for reopening,
	133	* clear out any awaiting events. The mask will prevent
	134	* any new __iio_push_event calls running.
	135	*/
2c00193f	136	kfifo_reset_out(&ev_int->det_events);
1b9dc91e	137	spin_unlock_irq(&ev_int->wait.lock);
0a769a95 LPC	138
	139	return 0;
	140	}
	141
	142	static const struct file_operations iio_event_chrdev_fileops = {
	143	.read = iio_event_chrdev_read,
e18045ed	144	.poll = iio_event_poll,
0a769a95 LPC	145	.release = iio_event_chrdev_release,
	146	.owner = THIS_MODULE,
	147	.llseek = noop_llseek,
	148	};
	149
	150	int iio_event_getfd(struct iio_dev *indio_dev)
	151	{
	152	struct iio_event_interface *ev_int = indio_dev->event_interface;
	153	int fd;
	154
	155	if (ev_int == NULL)
	156	return -ENODEV;
	157
1b9dc91e	158	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	159	if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
1b9dc91e	160	spin_unlock_irq(&ev_int->wait.lock);
0a769a95 LPC	161	return -EBUSY;
0a769a95 LPC	162	}
1b9dc91e	163	spin_unlock_irq(&ev_int->wait.lock);
0a769a95 LPC	164	fd = anon_inode_getfd("iio:event",
	165	&iio_event_chrdev_fileops, ev_int, O_RDONLY);
	166	if (fd < 0) {
1b9dc91e	167	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	168	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
1b9dc91e	169	spin_unlock_irq(&ev_int->wait.lock);
0a769a95 LPC	170	}
	171	return fd;
	172	}
	173
	174	static const char * const iio_ev_type_text[] = {
	175	[IIO_EV_TYPE_THRESH] = "thresh",
	176	[IIO_EV_TYPE_MAG] = "mag",
	177	[IIO_EV_TYPE_ROC] = "roc",
	178	[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
	179	[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
	180	};
	181
	182	static const char * const iio_ev_dir_text[] = {
	183	[IIO_EV_DIR_EITHER] = "either",
	184	[IIO_EV_DIR_RISING] = "rising",
	185	[IIO_EV_DIR_FALLING] = "falling"
	186	};
	187
	188	static ssize_t iio_ev_state_store(struct device *dev,
	189	struct device_attribute *attr,
	190	const char *buf,
	191	size_t len)
	192	{
e53f5ac5	193	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	194	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	195	int ret;
	196	bool val;
	197
	198	ret = strtobool(buf, &val);
	199	if (ret < 0)
	200	return ret;
	201
	202	ret = indio_dev->info->write_event_config(indio_dev,
	203	this_attr->address,
	204	val);
	205	return (ret < 0) ? ret : len;
	206	}
	207
	208	static ssize_t iio_ev_state_show(struct device *dev,
	209	struct device_attribute *attr,
	210	char *buf)
	211	{
e53f5ac5	212	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	213	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	214	int val = indio_dev->info->read_event_config(indio_dev,
	215	this_attr->address);
	216
	217	if (val < 0)
	218	return val;
	219	else
	220	return sprintf(buf, "%d\n", val);
	221	}
	222
	223	static ssize_t iio_ev_value_show(struct device *dev,
	224	struct device_attribute *attr,
	225	char *buf)
	226	{
e53f5ac5	227	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	228	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	229	int val, ret;
	230
	231	ret = indio_dev->info->read_event_value(indio_dev,
	232	this_attr->address, &val);
	233	if (ret < 0)
	234	return ret;
	235
	236	return sprintf(buf, "%d\n", val);
	237	}
	238
	239	static ssize_t iio_ev_value_store(struct device *dev,
	240	struct device_attribute *attr,
	241	const char *buf,
	242	size_t len)
	243	{
e53f5ac5	244	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	245	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
948ad205	246	int val;
0a769a95 LPC	247	int ret;
	248
	249	if (!indio_dev->info->write_event_value)
	250	return -EINVAL;
	251
948ad205	252	ret = kstrtoint(buf, 10, &val);
0a769a95 LPC	253	if (ret)
	254	return ret;
	255
	256	ret = indio_dev->info->write_event_value(indio_dev, this_attr->address,
	257	val);
	258	if (ret < 0)
	259	return ret;
	260
	261	return len;
	262	}
	263
	264	static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
	265	struct iio_chan_spec const *chan)
	266	{
	267	int ret = 0, i, attrcount = 0;
	268	u64 mask = 0;
	269	char *postfix;
	270	if (!chan->event_mask)
	271	return 0;
	272
	273	for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) {
	274	postfix = kasprintf(GFP_KERNEL, "%s_%s_en",
	275	iio_ev_type_text[i/IIO_EV_DIR_MAX],
	276	iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
	277	if (postfix == NULL) {
	278	ret = -ENOMEM;
	279	goto error_ret;
	280	}
	281	if (chan->modified)
	282	mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel,
	283	i/IIO_EV_DIR_MAX,
	284	i%IIO_EV_DIR_MAX);
	285	else if (chan->differential)
	286	mask = IIO_EVENT_CODE(chan->type,
	287	0, 0,
	288	i%IIO_EV_DIR_MAX,
	289	i/IIO_EV_DIR_MAX,
	290	0,
	291	chan->channel,
	292	chan->channel2);
	293	else
	294	mask = IIO_UNMOD_EVENT_CODE(chan->type,
	295	chan->channel,
	296	i/IIO_EV_DIR_MAX,
	297	i%IIO_EV_DIR_MAX);
	298
	299	ret = __iio_add_chan_devattr(postfix,
	300	chan,
	301	&iio_ev_state_show,
	302	iio_ev_state_store,
	303	mask,
	304	0,
	305	&indio_dev->dev,
	306	&indio_dev->event_interface->
	307	dev_attr_list);
	308	kfree(postfix);
	309	if (ret)
	310	goto error_ret;
	311	attrcount++;
	312	postfix = kasprintf(GFP_KERNEL, "%s_%s_value",
	313	iio_ev_type_text[i/IIO_EV_DIR_MAX],
	314	iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
	315	if (postfix == NULL) {
	316	ret = -ENOMEM;
317	goto error_ret;
318	}
319	ret = __iio_add_chan_devattr(postfix, chan,
320	iio_ev_value_show,
321	iio_ev_value_store,
322	mask,
323	0,
324	&indio_dev->dev,
325	&indio_dev->event_interface->
326	dev_attr_list);
327	kfree(postfix);
328	if (ret)
329	goto error_ret;
330	attrcount++;
331	}
332	ret = attrcount;
333	error_ret:
334	return ret;
335	}
336
337	static inline void __iio_remove_event_config_attrs(struct iio_dev *indio_dev)
338	{
339	struct iio_dev_attr p, n;
340	list_for_each_entry_safe(p, n,
341	&indio_dev->event_interface->
342	dev_attr_list, l) {
343	kfree(p->dev_attr.attr.name);
344	kfree(p);
345	}
346	}
347
348	static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
349	{
350	int j, ret, attrcount = 0;
351
0a769a95 LPC	352	/* Dynically created from the channels array */
	353	for (j = 0; j < indio_dev->num_channels; j++) {
	354	ret = iio_device_add_event_sysfs(indio_dev,
	355	&indio_dev->channels[j]);
	356	if (ret < 0)
e3db9ef6	357	return ret;
0a769a95 LPC	358	attrcount += ret;
	359	}
	360	return attrcount;
0a769a95 LPC	361	}
	362
	363	static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
	364	{
	365	int j;
	366
	367	for (j = 0; j < indio_dev->num_channels; j++)
	368	if (indio_dev->channels[j].event_mask != 0)
	369	return true;
	370	return false;
	371	}
	372
	373	static void iio_setup_ev_int(struct iio_event_interface *ev_int)
	374	{
2c00193f	375	INIT_KFIFO(ev_int->det_events);
0a769a95	376	init_waitqueue_head(&ev_int->wait);
6fa3eb70	377	mutex_init(&ev_int->read_lock);
0a769a95 LPC	378	}
	379
	380	static const char *iio_event_group_name = "events";
	381	int iio_device_register_eventset(struct iio_dev *indio_dev)
	382	{
	383	struct iio_dev_attr *p;
	384	int ret = 0, attrcount_orig = 0, attrcount, attrn;
	385	struct attribute **attr;
	386
	387	if (!(indio_dev->info->event_attrs \|\|
	388	iio_check_for_dynamic_events(indio_dev)))
	389	return 0;
	390
	391	indio_dev->event_interface =
	392	kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
	393	if (indio_dev->event_interface == NULL) {
	394	ret = -ENOMEM;
	395	goto error_ret;
	396	}
	397
46b24311 SH	398	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
46b24311 SH	399
0a769a95 LPC	400	iio_setup_ev_int(indio_dev->event_interface);
	401	if (indio_dev->info->event_attrs != NULL) {
	402	attr = indio_dev->info->event_attrs->attrs;
	403	while (*attr++ != NULL)
	404	attrcount_orig++;
	405	}
	406	attrcount = attrcount_orig;
	407	if (indio_dev->channels) {
	408	ret = __iio_add_event_config_attrs(indio_dev);
	409	if (ret < 0)
	410	goto error_free_setup_event_lines;
	411	attrcount += ret;
	412	}
	413
	414	indio_dev->event_interface->group.name = iio_event_group_name;
	415	indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
	416	sizeof(indio_dev->event_interface->group.attrs[0]),
	417	GFP_KERNEL);
	418	if (indio_dev->event_interface->group.attrs == NULL) {
	419	ret = -ENOMEM;
	420	goto error_free_setup_event_lines;
	421	}
	422	if (indio_dev->info->event_attrs)
	423	memcpy(indio_dev->event_interface->group.attrs,
	424	indio_dev->info->event_attrs->attrs,
	425	sizeof(indio_dev->event_interface->group.attrs[0])
	426	*attrcount_orig);
	427	attrn = attrcount_orig;
	428	/* Add all elements from the list. */
	429	list_for_each_entry(p,
	430	&indio_dev->event_interface->dev_attr_list,
	431	l)
	432	indio_dev->event_interface->group.attrs[attrn++] =
	433	&p->dev_attr.attr;
	434	indio_dev->groups[indio_dev->groupcounter++] =
	435	&indio_dev->event_interface->group;
	436
	437	return 0;
	438
	439	error_free_setup_event_lines:
	440	__iio_remove_event_config_attrs(indio_dev);
6fa3eb70	441	mutex_destroy(&indio_dev->event_interface->read_lock);
0a769a95 LPC	442	kfree(indio_dev->event_interface);
	443	error_ret:
	444
	445	return ret;
	446	}
	447
	448	void iio_device_unregister_eventset(struct iio_dev *indio_dev)
	449	{
	450	if (indio_dev->event_interface == NULL)
	451	return;
	452	__iio_remove_event_config_attrs(indio_dev);
	453	kfree(indio_dev->event_interface->group.attrs);
6fa3eb70	454	mutex_destroy(&indio_dev->event_interface->read_lock);
0a769a95 LPC	455	kfree(indio_dev->event_interface);
0a769a95 LPC	456	}