[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / staging / iio / industrialio-trigger.c

/* The industrial I/O core, trigger handling functions
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/idr.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/slab.h>

#include "iio.h"
#include "trigger.h"
#include "trigger_consumer.h"

/* RFC - Question of approach
 * Make the common case (single sensor single trigger)
 * simple by starting trigger capture from when first sensors
 * is added.
 *
 * Complex simultaneous start requires use of 'hold' functionality
 * of the trigger. (not implemented)
 *
 * Any other suggestions?
 */


static DEFINE_IDR(iio_trigger_idr);
static DEFINE_SPINLOCK(iio_trigger_idr_lock);

/* Single list of all available triggers */
static LIST_HEAD(iio_trigger_list);
static DEFINE_MUTEX(iio_trigger_list_lock);

/**
 * iio_trigger_register_sysfs() - create a device for this trigger
 * @trig_info:	the trigger
 *
 * Also adds any control attribute registered by the trigger driver
 **/
static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
{
	int ret = 0;

	if (trig_info->control_attrs)
		ret = sysfs_create_group(&trig_info->dev.kobj,
					 trig_info->control_attrs);

	return ret;
}

static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
{
	if (trig_info->control_attrs)
		sysfs_remove_group(&trig_info->dev.kobj,
				   trig_info->control_attrs);
}


/**
 * iio_trigger_register_id() - get a unique id for this trigger
 * @trig_info:	the trigger
 **/
static int iio_trigger_register_id(struct iio_trigger *trig_info)
{
	int ret = 0;

idr_again:
	if (unlikely(idr_pre_get(&iio_trigger_idr, GFP_KERNEL) == 0))
		return -ENOMEM;

	spin_lock(&iio_trigger_idr_lock);
	ret = idr_get_new(&iio_trigger_idr, NULL, &trig_info->id);
	spin_unlock(&iio_trigger_idr_lock);
	if (unlikely(ret == -EAGAIN))
		goto idr_again;
	else if (likely(!ret))
		trig_info->id = trig_info->id & MAX_ID_MASK;

	return ret;
}

/**
 * iio_trigger_unregister_id() - free up unique id for use by another trigger
 * @trig_info: the trigger
 **/
static void iio_trigger_unregister_id(struct iio_trigger *trig_info)
{
	spin_lock(&iio_trigger_idr_lock);
	idr_remove(&iio_trigger_idr, trig_info->id);
	spin_unlock(&iio_trigger_idr_lock);
}

int iio_trigger_register(struct iio_trigger *trig_info)
{
	int ret;

	ret = iio_trigger_register_id(trig_info);
	if (ret)
		goto error_ret;
	/* Set the name used for the sysfs directory etc */
	dev_set_name(&trig_info->dev, "trigger%ld",
		     (unsigned long) trig_info->id);

	ret = device_add(&trig_info->dev);
	if (ret)
		goto error_unregister_id;

	ret = iio_trigger_register_sysfs(trig_info);
	if (ret)
		goto error_device_del;

	/* Add to list of available triggers held by the IIO core */
	mutex_lock(&iio_trigger_list_lock);
	list_add_tail(&trig_info->list, &iio_trigger_list);
	mutex_unlock(&iio_trigger_list_lock);

	return 0;

error_device_del:
	device_del(&trig_info->dev);
error_unregister_id:
	iio_trigger_unregister_id(trig_info);
error_ret:
	return ret;
}
EXPORT_SYMBOL(iio_trigger_register);

void iio_trigger_unregister(struct iio_trigger *trig_info)
{
	struct iio_trigger *cursor;

	mutex_lock(&iio_trigger_list_lock);
	list_for_each_entry(cursor, &iio_trigger_list, list)
		if (cursor == trig_info) {
			list_del(&cursor->list);
			break;
		}
	mutex_unlock(&iio_trigger_list_lock);

	iio_trigger_unregister_sysfs(trig_info);
	iio_trigger_unregister_id(trig_info);
	/* Possible issue in here */
	device_unregister(&trig_info->dev);
}
EXPORT_SYMBOL(iio_trigger_unregister);

struct iio_trigger *iio_trigger_find_by_name(const char *name, size_t len)
{
	struct iio_trigger *trig;
	bool found = false;

	if (len && name[len - 1] == '\n')
		len--;

	mutex_lock(&iio_trigger_list_lock);
	list_for_each_entry(trig, &iio_trigger_list, list) {
		if (strncmp(trig->name, name, len) == 0) {
			found = true;
			break;
		}
	}
	mutex_unlock(&iio_trigger_list_lock);

	return found ? trig : NULL;
}
EXPORT_SYMBOL(iio_trigger_find_by_name);

void iio_trigger_poll(struct iio_trigger *trig)
{
	struct iio_poll_func *pf_cursor;

	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
		if (pf_cursor->poll_func_immediate) {
			pf_cursor->poll_func_immediate(pf_cursor->private_data);
			trig->use_count++;
		}
	}
	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
		if (pf_cursor->poll_func_main) {
			pf_cursor->poll_func_main(pf_cursor->private_data);
			trig->use_count++;
		}
	}
}
EXPORT_SYMBOL(iio_trigger_poll);

void iio_trigger_notify_done(struct iio_trigger *trig)
{
	trig->use_count--;
	if (trig->use_count == 0 && trig->try_reenable)
		if (trig->try_reenable(trig)) {
			/* Missed and interrupt so launch new poll now */
			trig->timestamp = 0;
			iio_trigger_poll(trig);
		}
}
EXPORT_SYMBOL(iio_trigger_notify_done);

/**
 * iio_trigger_read_name() - retrieve useful identifying name
 **/
ssize_t iio_trigger_read_name(struct device *dev,
			      struct device_attribute *attr,
			      char *buf)
{
	struct iio_trigger *trig = dev_get_drvdata(dev);
	return sprintf(buf, "%s\n", trig->name);
}
EXPORT_SYMBOL(iio_trigger_read_name);

/* Trigger Consumer related functions */

/* Complexity in here.  With certain triggers (datardy) an acknowledgement
 * may be needed if the pollfuncs do not include the data read for the
 * triggering device.
 * This is not currently handled.  Alternative of not enabling trigger unless
 * the relevant function is in there may be the best option.
 */
/* Worth protecting against double additions?*/
int iio_trigger_attach_poll_func(struct iio_trigger *trig,
				 struct iio_poll_func *pf)
{
	int ret = 0;
	unsigned long flags;

	spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
	list_add_tail(&pf->list, &trig->pollfunc_list);
	spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);

	if (trig->set_trigger_state)
		ret = trig->set_trigger_state(trig, true);
	if (ret) {
		printk(KERN_ERR "set trigger state failed\n");
		list_del(&pf->list);
	}
	return ret;
}
EXPORT_SYMBOL(iio_trigger_attach_poll_func);

int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
				  struct iio_poll_func *pf)
{
	struct iio_poll_func *pf_cursor;
	unsigned long flags;
	int ret = -EINVAL;

	spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list)
		if (pf_cursor == pf) {
			ret = 0;
			break;
		}
	if (!ret) {
		if (list_is_singular(&trig->pollfunc_list)
		    && trig->set_trigger_state) {
			spin_unlock_irqrestore(&trig->pollfunc_list_lock,
					       flags);
			/* May sleep hence cannot hold the spin lock */
			ret = trig->set_trigger_state(trig, false);
			if (ret)
				goto error_ret;
			spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
		}
		/*
		 * Now we can delete safe in the knowledge that, if this is
		 * the last pollfunc then we have disabled the trigger anyway
		 * and so nothing should be able to call the pollfunc.
		 */
		list_del(&pf_cursor->list);
	}
	spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);

error_ret:
	return ret;
}
EXPORT_SYMBOL(iio_trigger_dettach_poll_func);

/**
 * iio_trigger_read_currrent() trigger consumer sysfs query which trigger
 *
 * For trigger consumers the current_trigger interface allows the trigger
 * used by the device to be queried.
 **/
static ssize_t iio_trigger_read_current(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	int len = 0;
	if (dev_info->trig)
		len = snprintf(buf,
			       IIO_TRIGGER_NAME_LENGTH,
			       "%s\n",
			       dev_info->trig->name);
	return len;
}

/**
 * iio_trigger_write_current() trigger consumer sysfs set current trigger
 *
 * For trigger consumers the current_trigger interface allows the trigger
 * used for this device to be specified at run time based on the triggers
 * name.
 **/
static ssize_t iio_trigger_write_current(struct device *dev,
					 struct device_attribute *attr,
					 const char *buf,
					 size_t len)
{
	struct iio_dev *dev_info = dev_get_drvdata(dev);
	struct iio_trigger *oldtrig = dev_info->trig;
	mutex_lock(&dev_info->mlock);
	if (dev_info->currentmode == INDIO_RING_TRIGGERED) {
		mutex_unlock(&dev_info->mlock);
		return -EBUSY;
	}
	mutex_unlock(&dev_info->mlock);

	len = len < IIO_TRIGGER_NAME_LENGTH ? len : IIO_TRIGGER_NAME_LENGTH;

	dev_info->trig = iio_trigger_find_by_name(buf, len);
	if (oldtrig && dev_info->trig != oldtrig)
		iio_put_trigger(oldtrig);
	if (dev_info->trig)
		iio_get_trigger(dev_info->trig);

	return len;
}

static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
		   iio_trigger_read_current,
		   iio_trigger_write_current);

static struct attribute *iio_trigger_consumer_attrs[] = {
	&dev_attr_current_trigger.attr,
	NULL,
};

static const struct attribute_group iio_trigger_consumer_attr_group = {
	.name = "trigger",
	.attrs = iio_trigger_consumer_attrs,
};

static void iio_trig_release(struct device *device)
{
	struct iio_trigger *trig = to_iio_trigger(device);
	kfree(trig);
	iio_put();
}

static struct device_type iio_trig_type = {
	.release = iio_trig_release,
};

struct iio_trigger *iio_allocate_trigger(void)
{
	struct iio_trigger *trig;
	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	if (trig) {
		trig->dev.type = &iio_trig_type;
		trig->dev.bus = &iio_bus_type;
		device_initialize(&trig->dev);
		dev_set_drvdata(&trig->dev, (void *)trig);
		spin_lock_init(&trig->pollfunc_list_lock);
		INIT_LIST_HEAD(&trig->list);
		INIT_LIST_HEAD(&trig->pollfunc_list);
		iio_get();
	}
	return trig;
}
EXPORT_SYMBOL(iio_allocate_trigger);

void iio_free_trigger(struct iio_trigger *trig)
{
	if (trig)
		put_device(&trig->dev);
}
EXPORT_SYMBOL(iio_free_trigger);

int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
{
	int ret;
	ret = sysfs_create_group(&dev_info->dev.kobj,
				 &iio_trigger_consumer_attr_group);
	return ret;
}
EXPORT_SYMBOL(iio_device_register_trigger_consumer);

int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
{
	sysfs_remove_group(&dev_info->dev.kobj,
			   &iio_trigger_consumer_attr_group);
	return 0;
}
EXPORT_SYMBOL(iio_device_unregister_trigger_consumer);
Commit	Line	Data
1637db44 JC	1	/* The industrial I/O core, trigger handling functions
	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
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/idr.h>
	13	#include <linux/err.h>
	14	#include <linux/device.h>
	15	#include <linux/interrupt.h>
	16	#include <linux/list.h>
5a0e3ad6	17	#include <linux/slab.h>
1637db44 JC	18
	19	#include "iio.h"
	20	#include "trigger.h"
74112d3f	21	#include "trigger_consumer.h"
1637db44 JC	22
	23	/* RFC - Question of approach
	24	* Make the common case (single sensor single trigger)
	25	* simple by starting trigger capture from when first sensors
	26	* is added.
	27	*
	28	* Complex simultaneous start requires use of 'hold' functionality
	29	* of the trigger. (not implemented)
	30	*
	31	* Any other suggestions?
	32	*/
	33
	34
	35	static DEFINE_IDR(iio_trigger_idr);
	36	static DEFINE_SPINLOCK(iio_trigger_idr_lock);
	37
	38	/* Single list of all available triggers */
	39	static LIST_HEAD(iio_trigger_list);
	40	static DEFINE_MUTEX(iio_trigger_list_lock);
	41
	42	/**
	43	* iio_trigger_register_sysfs() - create a device for this trigger
	44	* @trig_info: the trigger
	45	*
	46	* Also adds any control attribute registered by the trigger driver
	47	**/
	48	static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
	49	{
	50	int ret = 0;
	51
	52	if (trig_info->control_attrs)
	53	ret = sysfs_create_group(&trig_info->dev.kobj,
	54	trig_info->control_attrs);
	55
	56	return ret;
	57	}
	58
	59	static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
	60	{
	61	if (trig_info->control_attrs)
	62	sysfs_remove_group(&trig_info->dev.kobj,
	63	trig_info->control_attrs);
	64	}
	65
	66
	67	/**
	68	* iio_trigger_register_id() - get a unique id for this trigger
	69	* @trig_info: the trigger
	70	**/
	71	static int iio_trigger_register_id(struct iio_trigger *trig_info)
	72	{
	73	int ret = 0;
	74
	75	idr_again:
	76	if (unlikely(idr_pre_get(&iio_trigger_idr, GFP_KERNEL) == 0))
	77	return -ENOMEM;
	78
	79	spin_lock(&iio_trigger_idr_lock);
	80	ret = idr_get_new(&iio_trigger_idr, NULL, &trig_info->id);
	81	spin_unlock(&iio_trigger_idr_lock);
	82	if (unlikely(ret == -EAGAIN))
	83	goto idr_again;
	84	else if (likely(!ret))
	85	trig_info->id = trig_info->id & MAX_ID_MASK;
86
87	return ret;
88	}
89
90	/**
91	* iio_trigger_unregister_id() - free up unique id for use by another trigger
92	* @trig_info: the trigger
93	**/
94	static void iio_trigger_unregister_id(struct iio_trigger *trig_info)
95	{
74112d3f GKH	96	spin_lock(&iio_trigger_idr_lock);
	97	idr_remove(&iio_trigger_idr, trig_info->id);
	98	spin_unlock(&iio_trigger_idr_lock);
1637db44 JC	99	}
	100
	101	int iio_trigger_register(struct iio_trigger *trig_info)
	102	{
	103	int ret;
	104
	105	ret = iio_trigger_register_id(trig_info);
	106	if (ret)
	107	goto error_ret;
	108	/* Set the name used for the sysfs directory etc */
	109	dev_set_name(&trig_info->dev, "trigger%ld",
	110	(unsigned long) trig_info->id);
	111
	112	ret = device_add(&trig_info->dev);
	113	if (ret)
	114	goto error_unregister_id;
	115
	116	ret = iio_trigger_register_sysfs(trig_info);
	117	if (ret)
	118	goto error_device_del;
	119
	120	/* Add to list of available triggers held by the IIO core */
	121	mutex_lock(&iio_trigger_list_lock);
	122	list_add_tail(&trig_info->list, &iio_trigger_list);
	123	mutex_unlock(&iio_trigger_list_lock);
	124
	125	return 0;
	126
	127	error_device_del:
	128	device_del(&trig_info->dev);
	129	error_unregister_id:
	130	iio_trigger_unregister_id(trig_info);
	131	error_ret:
	132	return ret;
	133	}
	134	EXPORT_SYMBOL(iio_trigger_register);
	135
	136	void iio_trigger_unregister(struct iio_trigger *trig_info)
	137	{
	138	struct iio_trigger *cursor;
	139
	140	mutex_lock(&iio_trigger_list_lock);
	141	list_for_each_entry(cursor, &iio_trigger_list, list)
	142	if (cursor == trig_info) {
	143	list_del(&cursor->list);
	144	break;
	145	}
	146	mutex_unlock(&iio_trigger_list_lock);
	147
	148	iio_trigger_unregister_sysfs(trig_info);
	149	iio_trigger_unregister_id(trig_info);
	150	/* Possible issue in here */
	151	device_unregister(&trig_info->dev);
	152	}
	153	EXPORT_SYMBOL(iio_trigger_unregister);
	154
	155	struct iio_trigger iio_trigger_find_by_name(const char name, size_t len)
	156	{
	157	struct iio_trigger *trig;
	158	bool found = false;
	159
7c327857 MH	160	if (len && name[len - 1] == '\n')
	161	len--;
	162
1637db44 JC	163	mutex_lock(&iio_trigger_list_lock);
	164	list_for_each_entry(trig, &iio_trigger_list, list) {
	165	if (strncmp(trig->name, name, len) == 0) {
	166	found = true;
	167	break;
	168	}
	169	}
	170	mutex_unlock(&iio_trigger_list_lock);
	171
	172	return found ? trig : NULL;
5f87404d	173	}
1637db44 JC	174	EXPORT_SYMBOL(iio_trigger_find_by_name);
	175
	176	void iio_trigger_poll(struct iio_trigger *trig)
	177	{
	178	struct iio_poll_func *pf_cursor;
	179
	180	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
	181	if (pf_cursor->poll_func_immediate) {
	182	pf_cursor->poll_func_immediate(pf_cursor->private_data);
	183	trig->use_count++;
	184	}
	185	}
	186	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
	187	if (pf_cursor->poll_func_main) {
	188	pf_cursor->poll_func_main(pf_cursor->private_data);
	189	trig->use_count++;
	190	}
	191	}
	192	}
	193	EXPORT_SYMBOL(iio_trigger_poll);
	194
	195	void iio_trigger_notify_done(struct iio_trigger *trig)
	196	{
	197	trig->use_count--;
	198	if (trig->use_count == 0 && trig->try_reenable)
	199	if (trig->try_reenable(trig)) {
	200	/* Missed and interrupt so launch new poll now */
	201	trig->timestamp = 0;
	202	iio_trigger_poll(trig);
	203	}
	204	}
	205	EXPORT_SYMBOL(iio_trigger_notify_done);
	206
	207	/**
	208	* iio_trigger_read_name() - retrieve useful identifying name
	209	**/
	210	ssize_t iio_trigger_read_name(struct device *dev,
	211	struct device_attribute *attr,
	212	char *buf)
	213	{
	214	struct iio_trigger *trig = dev_get_drvdata(dev);
	215	return sprintf(buf, "%s\n", trig->name);
	216	}
	217	EXPORT_SYMBOL(iio_trigger_read_name);
	218
	219	/* Trigger Consumer related functions */
	220
	221	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	222	* may be needed if the pollfuncs do not include the data read for the
	223	* triggering device.
	224	* This is not currently handled. Alternative of not enabling trigger unless
	225	* the relevant function is in there may be the best option.
	226	*/
	227	/* Worth protecting against double additions?*/
	228	int iio_trigger_attach_poll_func(struct iio_trigger *trig,
	229	struct iio_poll_func *pf)
	230	{
	231	int ret = 0;
	232	unsigned long flags;
	233
	234	spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
	235	list_add_tail(&pf->list, &trig->pollfunc_list);
	236	spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
	237
238	if (trig->set_trigger_state)
239	ret = trig->set_trigger_state(trig, true);
240	if (ret) {
241	printk(KERN_ERR "set trigger state failed\n");
242	list_del(&pf->list);
243	}
244	return ret;
245	}
246	EXPORT_SYMBOL(iio_trigger_attach_poll_func);
247
248	int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
249	struct iio_poll_func *pf)
250	{
251	struct iio_poll_func *pf_cursor;
252	unsigned long flags;
253	int ret = -EINVAL;
254
255	spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
256	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list)
257	if (pf_cursor == pf) {
258	ret = 0;
259	break;
260	}
261	if (!ret) {
262	if (list_is_singular(&trig->pollfunc_list)
263	&& trig->set_trigger_state) {
264	spin_unlock_irqrestore(&trig->pollfunc_list_lock,
265	flags);
266	/* May sleep hence cannot hold the spin lock */
267	ret = trig->set_trigger_state(trig, false);
268	if (ret)
269	goto error_ret;
270	spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
271	}
272	/*
273	* Now we can delete safe in the knowledge that, if this is
274	* the last pollfunc then we have disabled the trigger anyway
275	* and so nothing should be able to call the pollfunc.
276	*/
277	list_del(&pf_cursor->list);
278	}
279	spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
280
281	error_ret:
282	return ret;
283	}
284	EXPORT_SYMBOL(iio_trigger_dettach_poll_func);
285
286	/**
287	* iio_trigger_read_currrent() trigger consumer sysfs query which trigger
288	*
289	* For trigger consumers the current_trigger interface allows the trigger
290	* used by the device to be queried.
291	**/
292	static ssize_t iio_trigger_read_current(struct device *dev,
293	struct device_attribute *attr,
294	char *buf)
295	{
296	struct iio_dev *dev_info = dev_get_drvdata(dev);
297	int len = 0;
298	if (dev_info->trig)
299	len = snprintf(buf,
300	IIO_TRIGGER_NAME_LENGTH,
301	"%s\n",
302	dev_info->trig->name);
303	return len;
304	}
305
306	/**
307	* iio_trigger_write_current() trigger consumer sysfs set current trigger
308	*
309	* For trigger consumers the current_trigger interface allows the trigger
310	* used for this device to be specified at run time based on the triggers
311	* name.
312	**/
313	static ssize_t iio_trigger_write_current(struct device *dev,
314	struct device_attribute *attr,
315	const char *buf,
316	size_t len)
317	{
318	struct iio_dev *dev_info = dev_get_drvdata(dev);
319	struct iio_trigger *oldtrig = dev_info->trig;
320	mutex_lock(&dev_info->mlock);
321	if (dev_info->currentmode == INDIO_RING_TRIGGERED) {
322	mutex_unlock(&dev_info->mlock);
323	return -EBUSY;
324	}
325	mutex_unlock(&dev_info->mlock);
326
327	len = len < IIO_TRIGGER_NAME_LENGTH ? len : IIO_TRIGGER_NAME_LENGTH;
328
329	dev_info->trig = iio_trigger_find_by_name(buf, len);
330	if (oldtrig && dev_info->trig != oldtrig)
331	iio_put_trigger(oldtrig);
332	if (dev_info->trig)
333	iio_get_trigger(dev_info->trig);
334
335	return len;
336	}
337
74112d3f GKH	338	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	339	iio_trigger_read_current,
	340	iio_trigger_write_current);
1637db44 JC	341
	342	static struct attribute *iio_trigger_consumer_attrs[] = {
	343	&dev_attr_current_trigger.attr,
	344	NULL,
	345	};
	346
	347	static const struct attribute_group iio_trigger_consumer_attr_group = {
	348	.name = "trigger",
	349	.attrs = iio_trigger_consumer_attrs,
	350	};
	351
	352	static void iio_trig_release(struct device *device)
	353	{
	354	struct iio_trigger *trig = to_iio_trigger(device);
	355	kfree(trig);
	356	iio_put();
	357	}
	358
	359	static struct device_type iio_trig_type = {
	360	.release = iio_trig_release,
	361	};
	362
	363	struct iio_trigger *iio_allocate_trigger(void)
	364	{
	365	struct iio_trigger *trig;
	366	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	367	if (trig) {
	368	trig->dev.type = &iio_trig_type;
5aaaeba8	369	trig->dev.bus = &iio_bus_type;
1637db44 JC	370	device_initialize(&trig->dev);
	371	dev_set_drvdata(&trig->dev, (void *)trig);
	372	spin_lock_init(&trig->pollfunc_list_lock);
	373	INIT_LIST_HEAD(&trig->list);
	374	INIT_LIST_HEAD(&trig->pollfunc_list);
	375	iio_get();
	376	}
	377	return trig;
	378	}
	379	EXPORT_SYMBOL(iio_allocate_trigger);
	380
	381	void iio_free_trigger(struct iio_trigger *trig)
	382	{
	383	if (trig)
	384	put_device(&trig->dev);
	385	}
	386	EXPORT_SYMBOL(iio_free_trigger);
	387
	388	int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
	389	{
	390	int ret;
	391	ret = sysfs_create_group(&dev_info->dev.kobj,
	392	&iio_trigger_consumer_attr_group);
	393	return ret;
	394	}
	395	EXPORT_SYMBOL(iio_device_register_trigger_consumer);
	396
	397	int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
	398	{
	399	sysfs_remove_group(&dev_info->dev.kobj,
	400	&iio_trigger_consumer_attr_group);
	401	return 0;
	402	}
	403	EXPORT_SYMBOL(iio_device_unregister_trigger_consumer);
	404