[linux-2.6-block.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;
};

/**
 * 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
 **/
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_dev *indio_dev = filep->private_data;
	struct iio_event_interface *ev_int = indio_dev->event_interface;
	unsigned int events = 0;

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

	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_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;

	spin_lock_irq(&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_irq(ev_int->wait,
					!kfifo_is_empty(&ev_int->det_events) ||
					indio_dev->info == NULL);
		if (ret)
			goto error_unlock;
		if (indio_dev->info == NULL) {
			ret = -ENODEV;
			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_irq(&ev_int->wait.lock);

	return ret ? ret : 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;

	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);

	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;

	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);
	iio_device_get(indio_dev);

	fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
				indio_dev, O_RDONLY | O_CLOEXEC);
	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);
		iio_device_put(indio_dev);
	}
	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 const char * const iio_ev_info_text[] = {
	[IIO_EV_INFO_ENABLE] = "en",
	[IIO_EV_INFO_VALUE] = "value",
	[IIO_EV_INFO_HYSTERESIS] = "hysteresis",
};

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;

	if (indio_dev->info->write_event_config)
		ret = indio_dev->info->write_event_config(indio_dev,
			this_attr->address, val);
	else
		ret = indio_dev->info->write_event_config_new(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;

	if (indio_dev->info->read_event_config)
		val = indio_dev->info->read_event_config(indio_dev,
			this_attr->address);
	else
		val = indio_dev->info->read_event_config_new(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;
	int ret;

	if (indio_dev->info->read_event_value) {
		ret = indio_dev->info->read_event_value(indio_dev,
			this_attr->address, &val);
		if (ret < 0)
			return ret;
		return sprintf(buf, "%d\n", val);
	} else {
		ret = indio_dev->info->read_event_value_new(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 iio_format_value(buf, ret, val, val2);
	}
}

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 &&
		!indio_dev->info->write_event_value_new)
		return -EINVAL;

	if (indio_dev->info->write_event_value) {
		ret = kstrtoint(buf, 10, &val);
		if (ret)
			return ret;
		ret = indio_dev->info->write_event_value(indio_dev,
			this_attr->address, val);
	} else {
		ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
		if (ret)
			return ret;
		ret = indio_dev->info->write_event_value_new(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)) {
		postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
				iio_ev_type_text[type], iio_ev_dir_text[dir],
				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)
			return ret;

		attrcount++;
	}

	return attrcount;
}

static int iio_device_add_event_sysfs_new(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)
			goto error_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)
			goto error_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)
			goto error_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)
			goto error_ret;
		attrcount += ret;
	}
	ret = attrcount;
error_ret:
	return ret;
}

static int iio_device_add_event_sysfs_old(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->channel2,
						  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 int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
				      struct iio_chan_spec const *chan)
{
	if (chan->event_mask)
		return iio_device_add_event_sysfs_old(indio_dev, chan);
	else
		return iio_device_add_event_sysfs_new(indio_dev, chan);
}

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;
		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);
}

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_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
	kfree(indio_dev->event_interface);
error_ret:

	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
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
a7e57dce SK	45	/**
	46	* iio_push_event() - try to add event to the list for userspace reading
	47	* @indio_dev: IIO device structure
	48	* @ev_code: What event
	49	* @timestamp: When the event occurred
	50	**/
0a769a95 LPC	51	int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
	52	{
	53	struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f	54	struct iio_event_data ev;
1b9dc91e	55	unsigned long flags;
2c00193f	56	int copied;
0a769a95 LPC	57
0a769a95 LPC	58	/* Does anyone care? */
1b9dc91e	59	spin_lock_irqsave(&ev_int->wait.lock, flags);
0a769a95	60	if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
0a769a95	61
2c00193f LPC	62	ev.id = ev_code;
	63	ev.timestamp = timestamp;
	64
498d319b	65	copied = kfifo_put(&ev_int->det_events, ev);
2c00193f	66	if (copied != 0)
e18045ed	67	wake_up_locked_poll(&ev_int->wait, POLLIN);
43ba1100	68	}
1b9dc91e	69	spin_unlock_irqrestore(&ev_int->wait.lock, flags);
0a769a95	70
2c00193f	71	return 0;
0a769a95 LPC	72	}
	73	EXPORT_SYMBOL(iio_push_event);
	74
e18045ed LPC	75	/**
	76	* iio_event_poll() - poll the event queue to find out if it has data
	77	*/
	78	static unsigned int iio_event_poll(struct file *filep,
	79	struct poll_table_struct *wait)
	80	{
cadc2125 LPC	81	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	82	struct iio_event_interface *ev_int = indio_dev->event_interface;
e18045ed LPC	83	unsigned int events = 0;
e18045ed LPC	84
f18e7a06 LPC	85	if (!indio_dev->info)
	86	return -ENODEV;
	87
e18045ed LPC	88	poll_wait(filep, &ev_int->wait, wait);
e18045ed LPC	89
1b9dc91e	90	spin_lock_irq(&ev_int->wait.lock);
e18045ed LPC	91	if (!kfifo_is_empty(&ev_int->det_events))
e18045ed LPC	92	events = POLLIN \| POLLRDNORM;
1b9dc91e	93	spin_unlock_irq(&ev_int->wait.lock);
e18045ed LPC	94
	95	return events;
	96	}
	97
0a769a95 LPC	98	static ssize_t iio_event_chrdev_read(struct file *filep,
	99	char __user *buf,
	100	size_t count,
	101	loff_t *f_ps)
	102	{
cadc2125 LPC	103	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	104	struct iio_event_interface *ev_int = indio_dev->event_interface;
2c00193f	105	unsigned int copied;
0a769a95 LPC	106	int ret;
0a769a95 LPC	107
f18e7a06 LPC	108	if (!indio_dev->info)
	109	return -ENODEV;
	110
2c00193f	111	if (count < sizeof(struct iio_event_data))
0a769a95 LPC	112	return -EINVAL;
0a769a95 LPC	113
1b9dc91e	114	spin_lock_irq(&ev_int->wait.lock);
2c00193f	115	if (kfifo_is_empty(&ev_int->det_events)) {
0a769a95 LPC	116	if (filep->f_flags & O_NONBLOCK) {
0a769a95 LPC	117	ret = -EAGAIN;
43ba1100	118	goto error_unlock;
0a769a95	119	}
0a769a95	120	/* Blocking on device; waiting for something to be there */
1b9dc91e	121	ret = wait_event_interruptible_locked_irq(ev_int->wait,
d2f0a48f LPC	122	!kfifo_is_empty(&ev_int->det_events) \|\|
d2f0a48f LPC	123	indio_dev->info == NULL);
0a769a95	124	if (ret)
43ba1100	125	goto error_unlock;
d2f0a48f LPC	126	if (indio_dev->info == NULL) {
	127	ret = -ENODEV;
	128	goto error_unlock;
	129	}
0a769a95	130	/* Single access device so no one else can get the data */
0a769a95 LPC	131	}
0a769a95 LPC	132
2c00193f	133	ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
0a769a95	134
43ba1100	135	error_unlock:
1b9dc91e	136	spin_unlock_irq(&ev_int->wait.lock);
43ba1100	137
2c00193f	138	return ret ? ret : copied;
0a769a95 LPC	139	}
	140
	141	static int iio_event_chrdev_release(struct inode inode, struct file filep)
	142	{
cadc2125 LPC	143	struct iio_dev *indio_dev = filep->private_data;
cadc2125 LPC	144	struct iio_event_interface *ev_int = indio_dev->event_interface;
0a769a95	145
1b9dc91e	146	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	147	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
0a769a95 LPC	148	/*
	149	* In order to maintain a clean state for reopening,
	150	* clear out any awaiting events. The mask will prevent
	151	* any new __iio_push_event calls running.
	152	*/
2c00193f	153	kfifo_reset_out(&ev_int->det_events);
1b9dc91e	154	spin_unlock_irq(&ev_int->wait.lock);
0a769a95	155
cadc2125 LPC	156	iio_device_put(indio_dev);
cadc2125 LPC	157
0a769a95 LPC	158	return 0;
	159	}
	160
	161	static const struct file_operations iio_event_chrdev_fileops = {
	162	.read = iio_event_chrdev_read,
e18045ed	163	.poll = iio_event_poll,
0a769a95 LPC	164	.release = iio_event_chrdev_release,
	165	.owner = THIS_MODULE,
	166	.llseek = noop_llseek,
	167	};
	168
	169	int iio_event_getfd(struct iio_dev *indio_dev)
	170	{
	171	struct iio_event_interface *ev_int = indio_dev->event_interface;
	172	int fd;
	173
	174	if (ev_int == NULL)
	175	return -ENODEV;
	176
1b9dc91e	177	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	178	if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
1b9dc91e	179	spin_unlock_irq(&ev_int->wait.lock);
0a769a95 LPC	180	return -EBUSY;
0a769a95 LPC	181	}
1b9dc91e	182	spin_unlock_irq(&ev_int->wait.lock);
cadc2125 LPC	183	iio_device_get(indio_dev);
	184
	185	fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
e2aad1d5	186	indio_dev, O_RDONLY \| O_CLOEXEC);
0a769a95	187	if (fd < 0) {
1b9dc91e	188	spin_lock_irq(&ev_int->wait.lock);
a046c1e8	189	__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
1b9dc91e	190	spin_unlock_irq(&ev_int->wait.lock);
cadc2125	191	iio_device_put(indio_dev);
0a769a95 LPC	192	}
	193	return fd;
	194	}
	195
	196	static const char * const iio_ev_type_text[] = {
	197	[IIO_EV_TYPE_THRESH] = "thresh",
	198	[IIO_EV_TYPE_MAG] = "mag",
	199	[IIO_EV_TYPE_ROC] = "roc",
	200	[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
	201	[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
	202	};
	203
	204	static const char * const iio_ev_dir_text[] = {
	205	[IIO_EV_DIR_EITHER] = "either",
	206	[IIO_EV_DIR_RISING] = "rising",
	207	[IIO_EV_DIR_FALLING] = "falling"
	208	};
	209
b4e3ac0a LPC	210	static const char * const iio_ev_info_text[] = {
	211	[IIO_EV_INFO_ENABLE] = "en",
	212	[IIO_EV_INFO_VALUE] = "value",
ec6670ae	213	[IIO_EV_INFO_HYSTERESIS] = "hysteresis",
b4e3ac0a LPC	214	};
	215
	216	static enum iio_event_direction iio_ev_attr_dir(struct iio_dev_attr *attr)
	217	{
	218	return attr->c->event_spec[attr->address & 0xffff].dir;
	219	}
	220
	221	static enum iio_event_type iio_ev_attr_type(struct iio_dev_attr *attr)
	222	{
	223	return attr->c->event_spec[attr->address & 0xffff].type;
	224	}
	225
	226	static enum iio_event_info iio_ev_attr_info(struct iio_dev_attr *attr)
	227	{
	228	return (attr->address >> 16) & 0xffff;
	229	}
	230
0a769a95 LPC	231	static ssize_t iio_ev_state_store(struct device *dev,
	232	struct device_attribute *attr,
	233	const char *buf,
	234	size_t len)
	235	{
e53f5ac5	236	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95 LPC	237	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
	238	int ret;
	239	bool val;
	240
	241	ret = strtobool(buf, &val);
	242	if (ret < 0)
	243	return ret;
	244
b4e3ac0a LPC	245	if (indio_dev->info->write_event_config)
	246	ret = indio_dev->info->write_event_config(indio_dev,
	247	this_attr->address, val);
	248	else
	249	ret = indio_dev->info->write_event_config_new(indio_dev,
	250	this_attr->c, iio_ev_attr_type(this_attr),
	251	iio_ev_attr_dir(this_attr), val);
	252
0a769a95 LPC	253	return (ret < 0) ? ret : len;
	254	}
	255
	256	static ssize_t iio_ev_state_show(struct device *dev,
	257	struct device_attribute *attr,
	258	char *buf)
	259	{
e53f5ac5	260	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	261	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
b4e3ac0a	262	int val;
0a769a95	263
b4e3ac0a LPC	264	if (indio_dev->info->read_event_config)
	265	val = indio_dev->info->read_event_config(indio_dev,
	266	this_attr->address);
	267	else
	268	val = indio_dev->info->read_event_config_new(indio_dev,
	269	this_attr->c, iio_ev_attr_type(this_attr),
	270	iio_ev_attr_dir(this_attr));
0a769a95 LPC	271	if (val < 0)
	272	return val;
	273	else
	274	return sprintf(buf, "%d\n", val);
	275	}
	276
	277	static ssize_t iio_ev_value_show(struct device *dev,
	278	struct device_attribute *attr,
	279	char *buf)
	280	{
e53f5ac5	281	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	282	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
b4e3ac0a LPC	283	int val, val2;
b4e3ac0a LPC	284	int ret;
0a769a95	285
b4e3ac0a LPC	286	if (indio_dev->info->read_event_value) {
	287	ret = indio_dev->info->read_event_value(indio_dev,
	288	this_attr->address, &val);
	289	if (ret < 0)
	290	return ret;
	291	return sprintf(buf, "%d\n", val);
	292	} else {
	293	ret = indio_dev->info->read_event_value_new(indio_dev,
	294	this_attr->c, iio_ev_attr_type(this_attr),
	295	iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
	296	&val, &val2);
	297	if (ret < 0)
	298	return ret;
	299	return iio_format_value(buf, ret, val, val2);
	300	}
0a769a95 LPC	301	}
	302
	303	static ssize_t iio_ev_value_store(struct device *dev,
	304	struct device_attribute *attr,
	305	const char *buf,
	306	size_t len)
	307	{
e53f5ac5	308	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
0a769a95	309	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
b4e3ac0a	310	int val, val2;
0a769a95 LPC	311	int ret;
0a769a95 LPC	312
b4e3ac0a LPC	313	if (!indio_dev->info->write_event_value &&
b4e3ac0a LPC	314	!indio_dev->info->write_event_value_new)
0a769a95 LPC	315	return -EINVAL;
0a769a95 LPC	316
b4e3ac0a LPC	317	if (indio_dev->info->write_event_value) {
	318	ret = kstrtoint(buf, 10, &val);
	319	if (ret)
	320	return ret;
	321	ret = indio_dev->info->write_event_value(indio_dev,
	322	this_attr->address, val);
	323	} else {
	324	ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
	325	if (ret)
	326	return ret;
	327	ret = indio_dev->info->write_event_value_new(indio_dev,
	328	this_attr->c, iio_ev_attr_type(this_attr),
	329	iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
	330	val, val2);
	331	}
0a769a95 LPC	332	if (ret < 0)
	333	return ret;
	334
	335	return len;
	336	}
	337
b4e3ac0a LPC	338	static int iio_device_add_event(struct iio_dev *indio_dev,
	339	const struct iio_chan_spec *chan, unsigned int spec_index,
	340	enum iio_event_type type, enum iio_event_direction dir,
	341	enum iio_shared_by shared_by, const unsigned long *mask)
	342	{
	343	ssize_t (show)(struct device , struct device_attribute , char );
	344	ssize_t (store)(struct device , struct device_attribute *,
	345	const char *, size_t);
	346	unsigned int attrcount = 0;
	347	unsigned int i;
	348	char *postfix;
	349	int ret;
	350
	351	for_each_set_bit(i, mask, sizeof(*mask)) {
	352	postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
	353	iio_ev_type_text[type], iio_ev_dir_text[dir],
	354	iio_ev_info_text[i]);
	355	if (postfix == NULL)
	356	return -ENOMEM;
	357
	358	if (i == IIO_EV_INFO_ENABLE) {
	359	show = iio_ev_state_show;
	360	store = iio_ev_state_store;
	361	} else {
	362	show = iio_ev_value_show;
	363	store = iio_ev_value_store;
	364	}
	365
	366	ret = __iio_add_chan_devattr(postfix, chan, show, store,
	367	(i << 16) \| spec_index, shared_by, &indio_dev->dev,
	368	&indio_dev->event_interface->dev_attr_list);
	369	kfree(postfix);
	370
	371	if (ret)
	372	return ret;
	373
	374	attrcount++;
	375	}
	376
	377	return attrcount;
	378	}
	379
	380	static int iio_device_add_event_sysfs_new(struct iio_dev *indio_dev,
	381	struct iio_chan_spec const *chan)
	382	{
	383	int ret = 0, i, attrcount = 0;
	384	enum iio_event_direction dir;
	385	enum iio_event_type type;
	386
	387	for (i = 0; i < chan->num_event_specs; i++) {
	388	type = chan->event_spec[i].type;
	389	dir = chan->event_spec[i].dir;
	390
	391	ret = iio_device_add_event(indio_dev, chan, i, type, dir,
	392	IIO_SEPARATE, &chan->event_spec[i].mask_separate);
	393	if (ret < 0)
	394	goto error_ret;
	395	attrcount += ret;
	396
	397	ret = iio_device_add_event(indio_dev, chan, i, type, dir,
	398	IIO_SHARED_BY_TYPE,
	399	&chan->event_spec[i].mask_shared_by_type);
	400	if (ret < 0)
	401	goto error_ret;
402	attrcount += ret;
403
404	ret = iio_device_add_event(indio_dev, chan, i, type, dir,
405	IIO_SHARED_BY_DIR,
406	&chan->event_spec[i].mask_shared_by_dir);
407	if (ret < 0)
408	goto error_ret;
409	attrcount += ret;
410
411	ret = iio_device_add_event(indio_dev, chan, i, type, dir,
412	IIO_SHARED_BY_ALL,
413	&chan->event_spec[i].mask_shared_by_all);
414	if (ret < 0)
415	goto error_ret;
416	attrcount += ret;
417	}
418	ret = attrcount;
419	error_ret:
420	return ret;
421	}
422
423	static int iio_device_add_event_sysfs_old(struct iio_dev *indio_dev,
0a769a95 LPC	424	struct iio_chan_spec const *chan)
	425	{
	426	int ret = 0, i, attrcount = 0;
	427	u64 mask = 0;
	428	char *postfix;
	429	if (!chan->event_mask)
	430	return 0;
	431
	432	for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) {
	433	postfix = kasprintf(GFP_KERNEL, "%s_%s_en",
	434	iio_ev_type_text[i/IIO_EV_DIR_MAX],
	435	iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
	436	if (postfix == NULL) {
	437	ret = -ENOMEM;
	438	goto error_ret;
	439	}
	440	if (chan->modified)
2b0774df	441	mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel2,
0a769a95 LPC	442	i/IIO_EV_DIR_MAX,
	443	i%IIO_EV_DIR_MAX);
	444	else if (chan->differential)
	445	mask = IIO_EVENT_CODE(chan->type,
	446	0, 0,
	447	i%IIO_EV_DIR_MAX,
	448	i/IIO_EV_DIR_MAX,
	449	0,
	450	chan->channel,
	451	chan->channel2);
	452	else
	453	mask = IIO_UNMOD_EVENT_CODE(chan->type,
	454	chan->channel,
	455	i/IIO_EV_DIR_MAX,
	456	i%IIO_EV_DIR_MAX);
	457
	458	ret = __iio_add_chan_devattr(postfix,
	459	chan,
	460	&iio_ev_state_show,
	461	iio_ev_state_store,
	462	mask,
	463	0,
	464	&indio_dev->dev,
	465	&indio_dev->event_interface->
	466	dev_attr_list);
	467	kfree(postfix);
	468	if (ret)
	469	goto error_ret;
	470	attrcount++;
	471	postfix = kasprintf(GFP_KERNEL, "%s_%s_value",
	472	iio_ev_type_text[i/IIO_EV_DIR_MAX],
	473	iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
	474	if (postfix == NULL) {
	475	ret = -ENOMEM;
	476	goto error_ret;
	477	}
	478	ret = __iio_add_chan_devattr(postfix, chan,
	479	iio_ev_value_show,
	480	iio_ev_value_store,
	481	mask,
	482	0,
	483	&indio_dev->dev,
	484	&indio_dev->event_interface->
	485	dev_attr_list);
	486	kfree(postfix);
	487	if (ret)
	488	goto error_ret;
	489	attrcount++;
	490	}
	491	ret = attrcount;
	492	error_ret:
	493	return ret;
	494	}
	495
b4e3ac0a LPC	496
	497	static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
	498	struct iio_chan_spec const *chan)
	499	{
	500	if (chan->event_mask)
	501	return iio_device_add_event_sysfs_old(indio_dev, chan);
	502	else
	503	return iio_device_add_event_sysfs_new(indio_dev, chan);
	504	}
	505
0a769a95 LPC	506	static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
	507	{
	508	int j, ret, attrcount = 0;
	509
0a769a95 LPC	510	/* Dynically created from the channels array */
	511	for (j = 0; j < indio_dev->num_channels; j++) {
	512	ret = iio_device_add_event_sysfs(indio_dev,
	513	&indio_dev->channels[j]);
	514	if (ret < 0)
e3db9ef6	515	return ret;
0a769a95 LPC	516	attrcount += ret;
	517	}
	518	return attrcount;
0a769a95 LPC	519	}
	520
	521	static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
	522	{
	523	int j;
	524
b4e3ac0a	525	for (j = 0; j < indio_dev->num_channels; j++) {
0a769a95 LPC	526	if (indio_dev->channels[j].event_mask != 0)
0a769a95 LPC	527	return true;
b4e3ac0a LPC	528	if (indio_dev->channels[j].num_event_specs != 0)
	529	return true;
	530	}
0a769a95 LPC	531	return false;
	532	}
	533
	534	static void iio_setup_ev_int(struct iio_event_interface *ev_int)
	535	{
2c00193f	536	INIT_KFIFO(ev_int->det_events);
0a769a95 LPC	537	init_waitqueue_head(&ev_int->wait);
	538	}
	539
	540	static const char *iio_event_group_name = "events";
	541	int iio_device_register_eventset(struct iio_dev *indio_dev)
	542	{
	543	struct iio_dev_attr *p;
	544	int ret = 0, attrcount_orig = 0, attrcount, attrn;
	545	struct attribute **attr;
	546
	547	if (!(indio_dev->info->event_attrs \|\|
	548	iio_check_for_dynamic_events(indio_dev)))
	549	return 0;
	550
	551	indio_dev->event_interface =
	552	kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
	553	if (indio_dev->event_interface == NULL) {
	554	ret = -ENOMEM;
	555	goto error_ret;
	556	}
	557
46b24311 SH	558	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
46b24311 SH	559
0a769a95 LPC	560	iio_setup_ev_int(indio_dev->event_interface);
	561	if (indio_dev->info->event_attrs != NULL) {
	562	attr = indio_dev->info->event_attrs->attrs;
	563	while (*attr++ != NULL)
	564	attrcount_orig++;
	565	}
	566	attrcount = attrcount_orig;
	567	if (indio_dev->channels) {
	568	ret = __iio_add_event_config_attrs(indio_dev);
	569	if (ret < 0)
	570	goto error_free_setup_event_lines;
	571	attrcount += ret;
	572	}
	573
	574	indio_dev->event_interface->group.name = iio_event_group_name;
	575	indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
	576	sizeof(indio_dev->event_interface->group.attrs[0]),
	577	GFP_KERNEL);
	578	if (indio_dev->event_interface->group.attrs == NULL) {
	579	ret = -ENOMEM;
	580	goto error_free_setup_event_lines;
	581	}
	582	if (indio_dev->info->event_attrs)
	583	memcpy(indio_dev->event_interface->group.attrs,
	584	indio_dev->info->event_attrs->attrs,
	585	sizeof(indio_dev->event_interface->group.attrs[0])
	586	*attrcount_orig);
	587	attrn = attrcount_orig;
	588	/* Add all elements from the list. */
	589	list_for_each_entry(p,
	590	&indio_dev->event_interface->dev_attr_list,
	591	l)
	592	indio_dev->event_interface->group.attrs[attrn++] =
	593	&p->dev_attr.attr;
	594	indio_dev->groups[indio_dev->groupcounter++] =
	595	&indio_dev->event_interface->group;
	596
	597	return 0;
	598
	599	error_free_setup_event_lines:
84088ebd	600	iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
0a769a95 LPC	601	kfree(indio_dev->event_interface);
	602	error_ret:
	603
	604	return ret;
	605	}
	606
d2f0a48f LPC	607	/**
	608	* iio_device_wakeup_eventset - Wakes up the event waitqueue
	609	* @indio_dev: The IIO device
	610	*
	611	* Wakes up the event waitqueue used for poll() and blocking read().
	612	* Should usually be called when the device is unregistered.
	613	*/
	614	void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
	615	{
	616	if (indio_dev->event_interface == NULL)
	617	return;
	618	wake_up(&indio_dev->event_interface->wait);
	619	}
	620
0a769a95 LPC	621	void iio_device_unregister_eventset(struct iio_dev *indio_dev)
	622	{
	623	if (indio_dev->event_interface == NULL)
	624	return;
84088ebd	625	iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
0a769a95 LPC	626	kfree(indio_dev->event_interface->group.attrs);
	627	kfree(indio_dev->event_interface);
	628	}