[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)
{
	mutex_lock(&iio_trigger_list_lock);
	list_del(&trig_info->list);
	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);

static struct iio_trigger *iio_trigger_find_by_name(const char *name,
						    size_t len)
{
	struct iio_trigger *trig = NULL, *iter;

	mutex_lock(&iio_trigger_list_lock);
	list_for_each_entry(iter, &iio_trigger_list, list)
		if (sysfs_streq(iter->name, name)) {
			trig = iter;
			break;
		}
	mutex_unlock(&iio_trigger_list_lock);

	return trig;
}

void iio_trigger_poll(struct iio_trigger *trig, s64 time)
{
	int i;
	if (!trig->use_count) {
		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
			if (trig->subirqs[i].enabled) {
				trig->use_count++;
				generic_handle_irq(trig->subirq_base + i);
			}
	}
}
EXPORT_SYMBOL(iio_trigger_poll);

irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
{
	iio_trigger_poll(private, iio_get_time_ns());
	return IRQ_HANDLED;
}
EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);

void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
{
	int i;
	if (!trig->use_count) {
		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
			if (trig->subirqs[i].enabled) {
				trig->use_count++;
				handle_nested_irq(trig->subirq_base + i);
			}
	}
}
EXPORT_SYMBOL(iio_trigger_poll_chained);

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 */
			iio_trigger_poll(trig, 0);
		}
}
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;
	bool notinuse
		= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);

	pf->irq = iio_trigger_get_irq(trig);
	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
				   pf->type, pf->name,
				   pf);
	if (trig->set_trigger_state && notinuse)
		ret = trig->set_trigger_state(trig, true);

	return ret;
}
EXPORT_SYMBOL(iio_trigger_attach_poll_func);

int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
				  struct iio_poll_func *pf)
{
	int ret = 0;
	bool no_other_users
		= (bitmap_weight(trig->pool,
				 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
		   == 1);
	if (trig->set_trigger_state && no_other_users) {
		ret = trig->set_trigger_state(trig, false);
		if (ret)
			goto error_ret;
	}
	iio_trigger_put_irq(trig, pf->irq);
	free_irq(pf->irq, pf);

error_ret:
	return ret;
}
EXPORT_SYMBOL(iio_trigger_dettach_poll_func);

irqreturn_t iio_pollfunc_store_time(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	pf->timestamp = iio_get_time_ns();
	return IRQ_WAKE_THREAD;
}
EXPORT_SYMBOL(iio_pollfunc_store_time);

/**
 * 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 = sprintf(buf,
			      "%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);

	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);
	int i;

	if (trig->subirq_base) {
		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
			irq_modify_status(trig->subirq_base + i,
					  IRQ_NOAUTOEN,
					  IRQ_NOREQUEST | IRQ_NOPROBE);
			irq_set_chip(trig->subirq_base + i,
				     NULL);
			irq_set_handler(trig->subirq_base + i,
					NULL);
		}

		irq_free_descs(trig->subirq_base,
			       CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	}
	kfree(trig);
	iio_put();
}

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

static void iio_trig_subirqmask(struct irq_data *d)
{
	struct irq_chip *chip = irq_data_get_irq_chip(d);
	struct iio_trigger *trig
		= container_of(chip,
			       struct iio_trigger, subirq_chip);
	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
}

static void iio_trig_subirqunmask(struct irq_data *d)
{
	struct irq_chip *chip = irq_data_get_irq_chip(d);
	struct iio_trigger *trig
		= container_of(chip,
			       struct iio_trigger, subirq_chip);
	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
}

struct iio_trigger *iio_allocate_trigger_named(const char *name)
{
	struct iio_trigger *trig;
	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	if (trig) {
		int i;
		trig->dev.type = &iio_trig_type;
		trig->dev.bus = &iio_bus_type;
		device_initialize(&trig->dev);
		dev_set_drvdata(&trig->dev, (void *)trig);

		if (name) {
			mutex_init(&trig->pool_lock);
			trig->subirq_base
				= irq_alloc_descs(-1, 0,
					CONFIG_IIO_CONSUMERS_PER_TRIGGER,
					0);
			if (trig->subirq_base < 0) {
				kfree(trig);
				return NULL;
			}
			trig->name = name;
			trig->subirq_chip.name = name;
			trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
			trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
			for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
				irq_set_chip(trig->subirq_base + i,
					     &trig->subirq_chip);
				irq_set_handler(trig->subirq_base + i,
						&handle_simple_irq);
				irq_modify_status(trig->subirq_base + i,
						  IRQ_NOREQUEST | IRQ_NOAUTOEN,
						  IRQ_NOPROBE);
			}
		}
		iio_get();
	}
	return trig;
}
EXPORT_SYMBOL(iio_allocate_trigger_named);

struct iio_trigger *iio_allocate_trigger(void)
{
	return iio_allocate_trigger_named(NULL);
}
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);

int iio_triggered_ring_postenable(struct iio_dev *indio_dev)
{
	return indio_dev->trig
		? iio_trigger_attach_poll_func(indio_dev->trig,
					       indio_dev->pollfunc)
		: 0;
}
EXPORT_SYMBOL(iio_triggered_ring_postenable);

int iio_triggered_ring_predisable(struct iio_dev *indio_dev)
{
	return indio_dev->trig
		? iio_trigger_dettach_poll_func(indio_dev->trig,
						indio_dev->pollfunc)
		: 0;
}
EXPORT_SYMBOL(iio_triggered_ring_predisable);
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
1637db44 JC	34	static DEFINE_IDR(iio_trigger_idr);
	35	static DEFINE_SPINLOCK(iio_trigger_idr_lock);
	36
	37	/* Single list of all available triggers */
	38	static LIST_HEAD(iio_trigger_list);
	39	static DEFINE_MUTEX(iio_trigger_list_lock);
	40
	41	/**
	42	* iio_trigger_register_sysfs() - create a device for this trigger
	43	* @trig_info: the trigger
	44	*
	45	* Also adds any control attribute registered by the trigger driver
	46	**/
	47	static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
	48	{
	49	int ret = 0;
	50
	51	if (trig_info->control_attrs)
	52	ret = sysfs_create_group(&trig_info->dev.kobj,
	53	trig_info->control_attrs);
	54
	55	return ret;
	56	}
	57
	58	static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
	59	{
	60	if (trig_info->control_attrs)
	61	sysfs_remove_group(&trig_info->dev.kobj,
	62	trig_info->control_attrs);
	63	}
	64
	65
	66	/**
	67	* iio_trigger_register_id() - get a unique id for this trigger
	68	* @trig_info: the trigger
	69	**/
	70	static int iio_trigger_register_id(struct iio_trigger *trig_info)
	71	{
	72	int ret = 0;
	73
	74	idr_again:
	75	if (unlikely(idr_pre_get(&iio_trigger_idr, GFP_KERNEL) == 0))
	76	return -ENOMEM;
	77
	78	spin_lock(&iio_trigger_idr_lock);
	79	ret = idr_get_new(&iio_trigger_idr, NULL, &trig_info->id);
	80	spin_unlock(&iio_trigger_idr_lock);
	81	if (unlikely(ret == -EAGAIN))
	82	goto idr_again;
	83	else if (likely(!ret))
	84	trig_info->id = trig_info->id & MAX_ID_MASK;
	85
	86	return ret;
	87	}
	88
	89	/**
	90	* iio_trigger_unregister_id() - free up unique id for use by another trigger
	91	* @trig_info: the trigger
	92	**/
	93	static void iio_trigger_unregister_id(struct iio_trigger *trig_info)
	94	{
74112d3f GKH	95	spin_lock(&iio_trigger_idr_lock);
	96	idr_remove(&iio_trigger_idr, trig_info->id);
	97	spin_unlock(&iio_trigger_idr_lock);
1637db44 JC	98	}
	99
	100	int iio_trigger_register(struct iio_trigger *trig_info)
	101	{
	102	int ret;
	103
	104	ret = iio_trigger_register_id(trig_info);
	105	if (ret)
	106	goto error_ret;
	107	/* Set the name used for the sysfs directory etc */
	108	dev_set_name(&trig_info->dev, "trigger%ld",
	109	(unsigned long) trig_info->id);
	110
	111	ret = device_add(&trig_info->dev);
	112	if (ret)
	113	goto error_unregister_id;
	114
	115	ret = iio_trigger_register_sysfs(trig_info);
	116	if (ret)
	117	goto error_device_del;
	118
	119	/* Add to list of available triggers held by the IIO core */
	120	mutex_lock(&iio_trigger_list_lock);
	121	list_add_tail(&trig_info->list, &iio_trigger_list);
	122	mutex_unlock(&iio_trigger_list_lock);
	123
	124	return 0;
	125
	126	error_device_del:
	127	device_del(&trig_info->dev);
	128	error_unregister_id:
	129	iio_trigger_unregister_id(trig_info);
	130	error_ret:
	131	return ret;
	132	}
	133	EXPORT_SYMBOL(iio_trigger_register);
	134
	135	void iio_trigger_unregister(struct iio_trigger *trig_info)
	136	{
1637db44	137	mutex_lock(&iio_trigger_list_lock);
582e5489	138	list_del(&trig_info->list);
1637db44 JC	139	mutex_unlock(&iio_trigger_list_lock);
	140
	141	iio_trigger_unregister_sysfs(trig_info);
	142	iio_trigger_unregister_id(trig_info);
	143	/* Possible issue in here */
	144	device_unregister(&trig_info->dev);
	145	}
	146	EXPORT_SYMBOL(iio_trigger_unregister);
	147
f6517f22 JC	148	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	149	size_t len)
1637db44	150	{
f6517f22	151	struct iio_trigger trig = NULL, iter;
7c327857	152
1637db44	153	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	154	list_for_each_entry(iter, &iio_trigger_list, list)
	155	if (sysfs_streq(iter->name, name)) {
	156	trig = iter;
1637db44 JC	157	break;
1637db44 JC	158	}
1637db44 JC	159	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	160
f6517f22	161	return trig;
5f87404d	162	}
1637db44	163
7b2c33b1	164	void iio_trigger_poll(struct iio_trigger *trig, s64 time)
1637db44	165	{
d96d1337	166	int i;
d96d1337 JC	167	if (!trig->use_count) {
	168	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	169	if (trig->subirqs[i].enabled) {
	170	trig->use_count++;
	171	generic_handle_irq(trig->subirq_base + i);
	172	}
	173	}
1637db44 JC	174	}
1637db44 JC	175	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	176
	177	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	178	{
	179	iio_trigger_poll(private, iio_get_time_ns());
	180	return IRQ_HANDLED;
	181	}
	182	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	183
1f785681 JC	184	void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
	185	{
	186	int i;
	187	if (!trig->use_count) {
	188	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	189	if (trig->subirqs[i].enabled) {
	190	trig->use_count++;
	191	handle_nested_irq(trig->subirq_base + i);
	192	}
	193	}
	194	}
	195	EXPORT_SYMBOL(iio_trigger_poll_chained);
	196
1637db44 JC	197	void iio_trigger_notify_done(struct iio_trigger *trig)
	198	{
	199	trig->use_count--;
	200	if (trig->use_count == 0 && trig->try_reenable)
	201	if (trig->try_reenable(trig)) {
	202	/* Missed and interrupt so launch new poll now */
7b2c33b1	203	iio_trigger_poll(trig, 0);
1637db44 JC	204	}
	205	}
	206	EXPORT_SYMBOL(iio_trigger_notify_done);
	207
	208	/**
	209	* iio_trigger_read_name() - retrieve useful identifying name
	210	**/
	211	ssize_t iio_trigger_read_name(struct device *dev,
	212	struct device_attribute *attr,
	213	char *buf)
	214	{
	215	struct iio_trigger *trig = dev_get_drvdata(dev);
	216	return sprintf(buf, "%s\n", trig->name);
	217	}
	218	EXPORT_SYMBOL(iio_trigger_read_name);
	219
	220	/* Trigger Consumer related functions */
	221
	222	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	223	* may be needed if the pollfuncs do not include the data read for the
	224	* triggering device.
	225	* This is not currently handled. Alternative of not enabling trigger unless
	226	* the relevant function is in there may be the best option.
	227	*/
	228	/* Worth protecting against double additions?*/
	229	int iio_trigger_attach_poll_func(struct iio_trigger *trig,
	230	struct iio_poll_func *pf)
	231	{
	232	int ret = 0;
51c060a0 JC	233	bool notinuse
	234	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	235
	236	pf->irq = iio_trigger_get_irq(trig);
	237	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	238	pf->type, pf->name,
	239	pf);
	240	if (trig->set_trigger_state && notinuse)
	241	ret = trig->set_trigger_state(trig, true);
d96d1337	242
1637db44 JC	243	return ret;
	244	}
	245	EXPORT_SYMBOL(iio_trigger_attach_poll_func);
	246
	247	int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
	248	struct iio_poll_func *pf)
	249	{
51c060a0 JC	250	int ret = 0;
	251	bool no_other_users
	252	= (bitmap_weight(trig->pool,
	253	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	254	== 1);
	255	if (trig->set_trigger_state && no_other_users) {
	256	ret = trig->set_trigger_state(trig, false);
	257	if (ret)
	258	goto error_ret;
1637db44	259	}
51c060a0 JC	260	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	261	free_irq(pf->irq, pf);
1637db44 JC	262
	263	error_ret:
	264	return ret;
	265	}
	266	EXPORT_SYMBOL(iio_trigger_dettach_poll_func);
	267
d96d1337 JC	268	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	269	{
	270	struct iio_poll_func *pf = p;
	271	pf->timestamp = iio_get_time_ns();
	272	return IRQ_WAKE_THREAD;
	273	}
	274	EXPORT_SYMBOL(iio_pollfunc_store_time);
	275
1637db44	276	/**
751a3700	277	* iio_trigger_read_currrent() - trigger consumer sysfs query which trigger
1637db44 JC	278	*
	279	* For trigger consumers the current_trigger interface allows the trigger
	280	* used by the device to be queried.
	281	**/
	282	static ssize_t iio_trigger_read_current(struct device *dev,
	283	struct device_attribute *attr,
	284	char *buf)
	285	{
	286	struct iio_dev *dev_info = dev_get_drvdata(dev);
	287	int len = 0;
	288	if (dev_info->trig)
3c9bbf58 JC	289	len = sprintf(buf,
	290	"%s\n",
	291	dev_info->trig->name);
1637db44 JC	292	return len;
	293	}
	294
	295	/**
	296	* iio_trigger_write_current() trigger consumer sysfs set current trigger
	297	*
	298	* For trigger consumers the current_trigger interface allows the trigger
	299	* used for this device to be specified at run time based on the triggers
	300	* name.
	301	**/
	302	static ssize_t iio_trigger_write_current(struct device *dev,
	303	struct device_attribute *attr,
	304	const char *buf,
	305	size_t len)
	306	{
	307	struct iio_dev *dev_info = dev_get_drvdata(dev);
	308	struct iio_trigger *oldtrig = dev_info->trig;
	309	mutex_lock(&dev_info->mlock);
	310	if (dev_info->currentmode == INDIO_RING_TRIGGERED) {
	311	mutex_unlock(&dev_info->mlock);
	312	return -EBUSY;
	313	}
	314	mutex_unlock(&dev_info->mlock);
	315
1637db44 JC	316	dev_info->trig = iio_trigger_find_by_name(buf, len);
	317	if (oldtrig && dev_info->trig != oldtrig)
	318	iio_put_trigger(oldtrig);
	319	if (dev_info->trig)
	320	iio_get_trigger(dev_info->trig);
	321
	322	return len;
	323	}
	324
74112d3f GKH	325	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	326	iio_trigger_read_current,
	327	iio_trigger_write_current);
1637db44 JC	328
	329	static struct attribute *iio_trigger_consumer_attrs[] = {
	330	&dev_attr_current_trigger.attr,
	331	NULL,
	332	};
	333
	334	static const struct attribute_group iio_trigger_consumer_attr_group = {
	335	.name = "trigger",
	336	.attrs = iio_trigger_consumer_attrs,
	337	};
	338
	339	static void iio_trig_release(struct device *device)
	340	{
	341	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	342	int i;
	343
	344	if (trig->subirq_base) {
	345	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	346	irq_modify_status(trig->subirq_base + i,
	347	IRQ_NOAUTOEN,
	348	IRQ_NOREQUEST \| IRQ_NOPROBE);
	349	irq_set_chip(trig->subirq_base + i,
	350	NULL);
	351	irq_set_handler(trig->subirq_base + i,
	352	NULL);
	353	}
	354
	355	irq_free_descs(trig->subirq_base,
	356	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	357	}
1637db44 JC	358	kfree(trig);
	359	iio_put();
	360	}
	361
	362	static struct device_type iio_trig_type = {
	363	.release = iio_trig_release,
	364	};
	365
d96d1337 JC	366	static void iio_trig_subirqmask(struct irq_data *d)
	367	{
	368	struct irq_chip *chip = irq_data_get_irq_chip(d);
	369	struct iio_trigger *trig
	370	= container_of(chip,
	371	struct iio_trigger, subirq_chip);
	372	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	373	}
	374
	375	static void iio_trig_subirqunmask(struct irq_data *d)
	376	{
	377	struct irq_chip *chip = irq_data_get_irq_chip(d);
	378	struct iio_trigger *trig
	379	= container_of(chip,
	380	struct iio_trigger, subirq_chip);
	381	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	382	}
	383
	384	struct iio_trigger iio_allocate_trigger_named(const char name)
1637db44 JC	385	{
	386	struct iio_trigger *trig;
	387	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	388	if (trig) {
d96d1337	389	int i;
1637db44	390	trig->dev.type = &iio_trig_type;
5aaaeba8	391	trig->dev.bus = &iio_bus_type;
1637db44 JC	392	device_initialize(&trig->dev);
1637db44 JC	393	dev_set_drvdata(&trig->dev, (void *)trig);
d96d1337 JC	394
	395	if (name) {
	396	mutex_init(&trig->pool_lock);
	397	trig->subirq_base
	398	= irq_alloc_descs(-1, 0,
	399	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	400	0);
	401	if (trig->subirq_base < 0) {
	402	kfree(trig);
	403	return NULL;
	404	}
	405	trig->name = name;
	406	trig->subirq_chip.name = name;
	407	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	408	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	409	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	410	irq_set_chip(trig->subirq_base + i,
	411	&trig->subirq_chip);
	412	irq_set_handler(trig->subirq_base + i,
	413	&handle_simple_irq);
	414	irq_modify_status(trig->subirq_base + i,
	415	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	416	IRQ_NOPROBE);
	417	}
	418	}
1637db44 JC	419	iio_get();
	420	}
	421	return trig;
	422	}
d96d1337 JC	423	EXPORT_SYMBOL(iio_allocate_trigger_named);
	424
	425	struct iio_trigger *iio_allocate_trigger(void)
	426	{
	427	return iio_allocate_trigger_named(NULL);
	428	}
1637db44 JC	429	EXPORT_SYMBOL(iio_allocate_trigger);
	430
	431	void iio_free_trigger(struct iio_trigger *trig)
	432	{
	433	if (trig)
	434	put_device(&trig->dev);
	435	}
	436	EXPORT_SYMBOL(iio_free_trigger);
	437
	438	int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
	439	{
	440	int ret;
	441	ret = sysfs_create_group(&dev_info->dev.kobj,
	442	&iio_trigger_consumer_attr_group);
	443	return ret;
	444	}
	445	EXPORT_SYMBOL(iio_device_register_trigger_consumer);
	446
	447	int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
	448	{
	449	sysfs_remove_group(&dev_info->dev.kobj,
	450	&iio_trigger_consumer_attr_group);
	451	return 0;
	452	}
	453	EXPORT_SYMBOL(iio_device_unregister_trigger_consumer);
	454
c3db00cc JC	455	int iio_triggered_ring_postenable(struct iio_dev *indio_dev)
	456	{
	457	return indio_dev->trig
	458	? iio_trigger_attach_poll_func(indio_dev->trig,
	459	indio_dev->pollfunc)
	460	: 0;
	461	}
	462	EXPORT_SYMBOL(iio_triggered_ring_postenable);
	463
	464	int iio_triggered_ring_predisable(struct iio_dev *indio_dev)
	465	{
	466	return indio_dev->trig
	467	? iio_trigger_dettach_poll_func(indio_dev->trig,
	468	indio_dev->pollfunc)
	469	: 0;
	470	}
	471	EXPORT_SYMBOL(iio_triggered_ring_predisable);