[deliverable/linux.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/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 "iio_core.h"
#include "iio_core_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_read_name() - retrieve useful identifying name
 **/
static 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);
}

static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);

/**
 * 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)
{
	return sysfs_add_file_to_group(&trig_info->dev.kobj,
				       &dev_attr_name.attr,
				       NULL);
}

static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
{
	sysfs_remove_file_from_group(&trig_info->dev.kobj,
					   &dev_attr_name.attr,
					   NULL);
}


/**
 * 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->ops && trig->ops->try_reenable)
		if (trig->ops->try_reenable(trig)) {
			/* Missed and interrupt so launch new poll now */
			iio_trigger_poll(trig, 0);
		}
}
EXPORT_SYMBOL(iio_trigger_notify_done);

/* 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);

	/* Prevent the module being removed whilst attached to a trigger */
	__module_get(pf->indio_dev->info->driver_module);
	pf->irq = iio_trigger_get_irq(trig);
	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
				   pf->type, pf->name,
				   pf);
	if (trig->ops && trig->ops->set_trigger_state && notinuse)
		ret = trig->ops->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->ops && trig->ops->set_trigger_state && no_other_users) {
		ret = trig->ops->set_trigger_state(trig, false);
		if (ret)
			goto error_ret;
	}
	iio_trigger_put_irq(trig, pf->irq);
	free_irq(pf->irq, pf);
	module_put(pf->indio_dev->info->driver_module);

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);

struct iio_poll_func
*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
		    irqreturn_t (*thread)(int irq, void *p),
		    int type,
		    struct iio_dev *indio_dev,
		    const char *fmt,
		    ...)
{
	va_list vargs;
	struct iio_poll_func *pf;

	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	if (pf == NULL)
		return NULL;
	va_start(vargs, fmt);
	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	va_end(vargs);
	if (pf->name == NULL) {
		kfree(pf);
		return NULL;
	}
	pf->h = h;
	pf->thread = thread;
	pf->type = type;
	pf->indio_dev = indio_dev;

	return pf;
}
EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);

void iio_dealloc_pollfunc(struct iio_poll_func *pf)
{
	kfree(pf->name);
	kfree(pf);
}
EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);

/**
 * 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;
	struct iio_trigger *trig;
	int ret;

	mutex_lock(&dev_info->mlock);
	if (dev_info->currentmode == INDIO_RING_TRIGGERED) {
		mutex_unlock(&dev_info->mlock);
		return -EBUSY;
	}
	mutex_unlock(&dev_info->mlock);

	trig = iio_trigger_find_by_name(buf, len);

	if (trig && dev_info->info->validate_trigger) {
		ret = dev_info->info->validate_trigger(dev_info, trig);
		if (ret)
			return ret;
	}

	if (trig && trig->ops && trig->ops->validate_device) {
		ret = trig->ops->validate_device(trig, dev_info);
		if (ret)
			return ret;
	}

	dev_info->trig = trig;

	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->name);
	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(const char *fmt, ...)
{
	va_list vargs;
	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);

		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;
		}
		va_start(vargs, fmt);
		trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
		va_end(vargs);
		if (trig->name == NULL) {
			irq_free_descs(trig->subirq_base,
				       CONFIG_IIO_CONSUMERS_PER_TRIGGER);
			kfree(trig);
			return NULL;
		}
		trig->subirq_chip.name = trig->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();
		get_device(&trig->dev);
	}
	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)
{
	/* Clean up and associated but not attached triggers references */
	if (dev_info->trig)
		iio_put_trigger(dev_info->trig);
	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>
1637db44 JC	11	#include <linux/idr.h>
	12	#include <linux/err.h>
	13	#include <linux/device.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/list.h>
5a0e3ad6	16	#include <linux/slab.h>
1637db44 JC	17
	18	#include "iio.h"
	19	#include "trigger.h"
df9c1c42	20	#include "iio_core.h"
6aea1c36	21	#include "iio_core_trigger.h"
3f72395e	22	#include "trigger_consumer.h"
1637db44 JC	23
	24	/* RFC - Question of approach
	25	* Make the common case (single sensor single trigger)
	26	* simple by starting trigger capture from when first sensors
	27	* is added.
	28	*
	29	* Complex simultaneous start requires use of 'hold' functionality
	30	* of the trigger. (not implemented)
	31	*
	32	* Any other suggestions?
	33	*/
	34
1637db44 JC	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
59c85e82 JC	42	/**
	43	* iio_trigger_read_name() - retrieve useful identifying name
	44	**/
	45	static ssize_t iio_trigger_read_name(struct device *dev,
	46	struct device_attribute *attr,
	47	char *buf)
	48	{
	49	struct iio_trigger *trig = dev_get_drvdata(dev);
	50	return sprintf(buf, "%s\n", trig->name);
	51	}
	52
	53	static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
	54
1637db44 JC	55	/**
	56	* iio_trigger_register_sysfs() - create a device for this trigger
	57	* @trig_info: the trigger
	58	*
	59	* Also adds any control attribute registered by the trigger driver
	60	**/
	61	static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
	62	{
59c85e82 JC	63	return sysfs_add_file_to_group(&trig_info->dev.kobj,
	64	&dev_attr_name.attr,
	65	NULL);
1637db44 JC	66	}
	67
	68	static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
	69	{
59c85e82 JC	70	sysfs_remove_file_from_group(&trig_info->dev.kobj,
	71	&dev_attr_name.attr,
	72	NULL);
1637db44 JC	73	}
	74
	75
	76	/**
	77	* iio_trigger_register_id() - get a unique id for this trigger
	78	* @trig_info: the trigger
	79	**/
	80	static int iio_trigger_register_id(struct iio_trigger *trig_info)
	81	{
	82	int ret = 0;
	83
	84	idr_again:
	85	if (unlikely(idr_pre_get(&iio_trigger_idr, GFP_KERNEL) == 0))
	86	return -ENOMEM;
	87
	88	spin_lock(&iio_trigger_idr_lock);
	89	ret = idr_get_new(&iio_trigger_idr, NULL, &trig_info->id);
	90	spin_unlock(&iio_trigger_idr_lock);
	91	if (unlikely(ret == -EAGAIN))
	92	goto idr_again;
	93	else if (likely(!ret))
	94	trig_info->id = trig_info->id & MAX_ID_MASK;
	95
	96	return ret;
	97	}
	98
	99	/**
	100	* iio_trigger_unregister_id() - free up unique id for use by another trigger
	101	* @trig_info: the trigger
	102	**/
	103	static void iio_trigger_unregister_id(struct iio_trigger *trig_info)
	104	{
74112d3f GKH	105	spin_lock(&iio_trigger_idr_lock);
	106	idr_remove(&iio_trigger_idr, trig_info->id);
	107	spin_unlock(&iio_trigger_idr_lock);
1637db44 JC	108	}
	109
	110	int iio_trigger_register(struct iio_trigger *trig_info)
	111	{
	112	int ret;
	113
	114	ret = iio_trigger_register_id(trig_info);
	115	if (ret)
	116	goto error_ret;
	117	/* Set the name used for the sysfs directory etc */
	118	dev_set_name(&trig_info->dev, "trigger%ld",
	119	(unsigned long) trig_info->id);
	120
	121	ret = device_add(&trig_info->dev);
	122	if (ret)
	123	goto error_unregister_id;
	124
	125	ret = iio_trigger_register_sysfs(trig_info);
	126	if (ret)
	127	goto error_device_del;
	128
	129	/* Add to list of available triggers held by the IIO core */
	130	mutex_lock(&iio_trigger_list_lock);
	131	list_add_tail(&trig_info->list, &iio_trigger_list);
	132	mutex_unlock(&iio_trigger_list_lock);
	133
	134	return 0;
	135
	136	error_device_del:
	137	device_del(&trig_info->dev);
	138	error_unregister_id:
	139	iio_trigger_unregister_id(trig_info);
	140	error_ret:
	141	return ret;
	142	}
	143	EXPORT_SYMBOL(iio_trigger_register);
	144
	145	void iio_trigger_unregister(struct iio_trigger *trig_info)
	146	{
1637db44	147	mutex_lock(&iio_trigger_list_lock);
582e5489	148	list_del(&trig_info->list);
1637db44 JC	149	mutex_unlock(&iio_trigger_list_lock);
	150
	151	iio_trigger_unregister_sysfs(trig_info);
	152	iio_trigger_unregister_id(trig_info);
	153	/* Possible issue in here */
	154	device_unregister(&trig_info->dev);
	155	}
	156	EXPORT_SYMBOL(iio_trigger_unregister);
	157
f6517f22 JC	158	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	159	size_t len)
1637db44	160	{
f6517f22	161	struct iio_trigger trig = NULL, iter;
7c327857	162
1637db44	163	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	164	list_for_each_entry(iter, &iio_trigger_list, list)
	165	if (sysfs_streq(iter->name, name)) {
	166	trig = iter;
1637db44 JC	167	break;
1637db44 JC	168	}
1637db44 JC	169	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	170
f6517f22	171	return trig;
5f87404d	172	}
1637db44	173
7b2c33b1	174	void iio_trigger_poll(struct iio_trigger *trig, s64 time)
1637db44	175	{
d96d1337	176	int i;
d96d1337 JC	177	if (!trig->use_count) {
	178	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	179	if (trig->subirqs[i].enabled) {
	180	trig->use_count++;
	181	generic_handle_irq(trig->subirq_base + i);
	182	}
	183	}
1637db44 JC	184	}
1637db44 JC	185	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	186
	187	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	188	{
	189	iio_trigger_poll(private, iio_get_time_ns());
	190	return IRQ_HANDLED;
	191	}
	192	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	193
1f785681 JC	194	void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
	195	{
	196	int i;
	197	if (!trig->use_count) {
	198	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	199	if (trig->subirqs[i].enabled) {
	200	trig->use_count++;
	201	handle_nested_irq(trig->subirq_base + i);
	202	}
	203	}
	204	}
	205	EXPORT_SYMBOL(iio_trigger_poll_chained);
	206
1637db44 JC	207	void iio_trigger_notify_done(struct iio_trigger *trig)
	208	{
	209	trig->use_count--;
d29f73db JC	210	if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
d29f73db JC	211	if (trig->ops->try_reenable(trig)) {
1637db44	212	/* Missed and interrupt so launch new poll now */
7b2c33b1	213	iio_trigger_poll(trig, 0);
1637db44 JC	214	}
	215	}
	216	EXPORT_SYMBOL(iio_trigger_notify_done);
	217
1637db44 JC	218	/* Trigger Consumer related functions */
	219
	220	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	221	* may be needed if the pollfuncs do not include the data read for the
	222	* triggering device.
	223	* This is not currently handled. Alternative of not enabling trigger unless
	224	* the relevant function is in there may be the best option.
	225	*/
	226	/* Worth protecting against double additions?*/
	227	int iio_trigger_attach_poll_func(struct iio_trigger *trig,
	228	struct iio_poll_func *pf)
	229	{
	230	int ret = 0;
51c060a0 JC	231	bool notinuse
	232	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	233
f60c4a02 JC	234	/* Prevent the module being removed whilst attached to a trigger */
f60c4a02 JC	235	__module_get(pf->indio_dev->info->driver_module);
51c060a0 JC	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);
d29f73db JC	240	if (trig->ops && trig->ops->set_trigger_state && notinuse)
d29f73db JC	241	ret = trig->ops->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);
d29f73db JC	255	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
d29f73db JC	256	ret = trig->ops->set_trigger_state(trig, false);
51c060a0 JC	257	if (ret)
51c060a0 JC	258	goto error_ret;
1637db44	259	}
51c060a0 JC	260	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	261	free_irq(pf->irq, pf);
f60c4a02	262	module_put(pf->indio_dev->info->driver_module);
1637db44 JC	263
	264	error_ret:
	265	return ret;
	266	}
	267	EXPORT_SYMBOL(iio_trigger_dettach_poll_func);
	268
d96d1337 JC	269	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	270	{
	271	struct iio_poll_func *pf = p;
	272	pf->timestamp = iio_get_time_ns();
	273	return IRQ_WAKE_THREAD;
	274	}
	275	EXPORT_SYMBOL(iio_pollfunc_store_time);
	276
21b185f8 JC	277	struct iio_poll_func
	278	iio_alloc_pollfunc(irqreturn_t (h)(int irq, void *p),
	279	irqreturn_t (thread)(int irq, void p),
	280	int type,
e65bc6ac	281	struct iio_dev *indio_dev,
21b185f8 JC	282	const char *fmt,
	283	...)
	284	{
	285	va_list vargs;
	286	struct iio_poll_func *pf;
	287
	288	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	289	if (pf == NULL)
	290	return NULL;
	291	va_start(vargs, fmt);
	292	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	293	va_end(vargs);
	294	if (pf->name == NULL) {
	295	kfree(pf);
	296	return NULL;
	297	}
	298	pf->h = h;
	299	pf->thread = thread;
	300	pf->type = type;
e65bc6ac	301	pf->indio_dev = indio_dev;
21b185f8 JC	302
	303	return pf;
	304	}
	305	EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
	306
	307	void iio_dealloc_pollfunc(struct iio_poll_func *pf)
	308	{
	309	kfree(pf->name);
	310	kfree(pf);
	311	}
	312	EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
	313
1637db44	314	/**
751a3700	315	* iio_trigger_read_currrent() - trigger consumer sysfs query which trigger
1637db44 JC	316	*
	317	* For trigger consumers the current_trigger interface allows the trigger
	318	* used by the device to be queried.
	319	**/
	320	static ssize_t iio_trigger_read_current(struct device *dev,
	321	struct device_attribute *attr,
	322	char *buf)
	323	{
	324	struct iio_dev *dev_info = dev_get_drvdata(dev);
	325	int len = 0;
	326	if (dev_info->trig)
3c9bbf58 JC	327	len = sprintf(buf,
	328	"%s\n",
	329	dev_info->trig->name);
1637db44 JC	330	return len;
	331	}
	332
	333	/**
	334	* iio_trigger_write_current() trigger consumer sysfs set current trigger
	335	*
	336	* For trigger consumers the current_trigger interface allows the trigger
	337	* used for this device to be specified at run time based on the triggers
	338	* name.
	339	**/
	340	static ssize_t iio_trigger_write_current(struct device *dev,
	341	struct device_attribute *attr,
	342	const char *buf,
	343	size_t len)
	344	{
	345	struct iio_dev *dev_info = dev_get_drvdata(dev);
	346	struct iio_trigger *oldtrig = dev_info->trig;
43a4360e MH	347	struct iio_trigger *trig;
	348	int ret;
	349
1637db44 JC	350	mutex_lock(&dev_info->mlock);
	351	if (dev_info->currentmode == INDIO_RING_TRIGGERED) {
	352	mutex_unlock(&dev_info->mlock);
	353	return -EBUSY;
	354	}
	355	mutex_unlock(&dev_info->mlock);
	356
43a4360e MH	357	trig = iio_trigger_find_by_name(buf, len);
	358
	359	if (trig && dev_info->info->validate_trigger) {
	360	ret = dev_info->info->validate_trigger(dev_info, trig);
	361	if (ret)
	362	return ret;
	363	}
	364
d29f73db JC	365	if (trig && trig->ops && trig->ops->validate_device) {
d29f73db JC	366	ret = trig->ops->validate_device(trig, dev_info);
43a4360e MH	367	if (ret)
	368	return ret;
	369	}
	370
	371	dev_info->trig = trig;
	372
1637db44 JC	373	if (oldtrig && dev_info->trig != oldtrig)
	374	iio_put_trigger(oldtrig);
	375	if (dev_info->trig)
	376	iio_get_trigger(dev_info->trig);
	377
	378	return len;
	379	}
	380
74112d3f GKH	381	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	382	iio_trigger_read_current,
	383	iio_trigger_write_current);
1637db44 JC	384
	385	static struct attribute *iio_trigger_consumer_attrs[] = {
	386	&dev_attr_current_trigger.attr,
	387	NULL,
	388	};
	389
	390	static const struct attribute_group iio_trigger_consumer_attr_group = {
	391	.name = "trigger",
	392	.attrs = iio_trigger_consumer_attrs,
	393	};
	394
	395	static void iio_trig_release(struct device *device)
	396	{
	397	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	398	int i;
	399
	400	if (trig->subirq_base) {
	401	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	402	irq_modify_status(trig->subirq_base + i,
	403	IRQ_NOAUTOEN,
	404	IRQ_NOREQUEST \| IRQ_NOPROBE);
	405	irq_set_chip(trig->subirq_base + i,
	406	NULL);
	407	irq_set_handler(trig->subirq_base + i,
	408	NULL);
	409	}
	410
	411	irq_free_descs(trig->subirq_base,
	412	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	413	}
59c85e82	414	kfree(trig->name);
1637db44 JC	415	kfree(trig);
	416	iio_put();
	417	}
	418
	419	static struct device_type iio_trig_type = {
	420	.release = iio_trig_release,
	421	};
	422
d96d1337 JC	423	static void iio_trig_subirqmask(struct irq_data *d)
	424	{
	425	struct irq_chip *chip = irq_data_get_irq_chip(d);
	426	struct iio_trigger *trig
	427	= container_of(chip,
	428	struct iio_trigger, subirq_chip);
	429	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	430	}
	431
	432	static void iio_trig_subirqunmask(struct irq_data *d)
	433	{
	434	struct irq_chip *chip = irq_data_get_irq_chip(d);
	435	struct iio_trigger *trig
	436	= container_of(chip,
	437	struct iio_trigger, subirq_chip);
	438	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	439	}
	440
59c85e82	441	struct iio_trigger iio_allocate_trigger(const char fmt, ...)
1637db44	442	{
59c85e82	443	va_list vargs;
1637db44 JC	444	struct iio_trigger *trig;
	445	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	446	if (trig) {
d96d1337	447	int i;
1637db44	448	trig->dev.type = &iio_trig_type;
5aaaeba8	449	trig->dev.bus = &iio_bus_type;
1637db44 JC	450	device_initialize(&trig->dev);
1637db44 JC	451	dev_set_drvdata(&trig->dev, (void *)trig);
d96d1337	452
59c85e82 JC	453	mutex_init(&trig->pool_lock);
	454	trig->subirq_base
	455	= irq_alloc_descs(-1, 0,
	456	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	457	0);
	458	if (trig->subirq_base < 0) {
	459	kfree(trig);
	460	return NULL;
	461	}
	462	va_start(vargs, fmt);
	463	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	464	va_end(vargs);
	465	if (trig->name == NULL) {
	466	irq_free_descs(trig->subirq_base,
	467	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	468	kfree(trig);
	469	return NULL;
	470	}
	471	trig->subirq_chip.name = trig->name;
	472	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	473	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	474	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	475	irq_set_chip(trig->subirq_base + i,
	476	&trig->subirq_chip);
	477	irq_set_handler(trig->subirq_base + i,
	478	&handle_simple_irq);
	479	irq_modify_status(trig->subirq_base + i,
	480	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	481	IRQ_NOPROBE);
d96d1337	482	}
1637db44	483	iio_get();
5f9c035c	484	get_device(&trig->dev);
1637db44 JC	485	}
	486	return trig;
	487	}
	488	EXPORT_SYMBOL(iio_allocate_trigger);
	489
	490	void iio_free_trigger(struct iio_trigger *trig)
	491	{
	492	if (trig)
	493	put_device(&trig->dev);
	494	}
	495	EXPORT_SYMBOL(iio_free_trigger);
	496
	497	int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
	498	{
	499	int ret;
	500	ret = sysfs_create_group(&dev_info->dev.kobj,
	501	&iio_trigger_consumer_attr_group);
	502	return ret;
	503	}
	504	EXPORT_SYMBOL(iio_device_register_trigger_consumer);
	505
	506	int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
	507	{
5f9c035c JC	508	/* Clean up and associated but not attached triggers references */
	509	if (dev_info->trig)
	510	iio_put_trigger(dev_info->trig);
1637db44 JC	511	sysfs_remove_group(&dev_info->dev.kobj,
	512	&iio_trigger_consumer_attr_group);
	513	return 0;
	514	}
	515	EXPORT_SYMBOL(iio_device_unregister_trigger_consumer);
	516
c3db00cc JC	517	int iio_triggered_ring_postenable(struct iio_dev *indio_dev)
	518	{
	519	return indio_dev->trig
	520	? iio_trigger_attach_poll_func(indio_dev->trig,
	521	indio_dev->pollfunc)
	522	: 0;
	523	}
	524	EXPORT_SYMBOL(iio_triggered_ring_postenable);
	525
	526	int iio_triggered_ring_predisable(struct iio_dev *indio_dev)
	527	{
	528	return indio_dev->trig
	529	? iio_trigger_dettach_poll_func(indio_dev->trig,
	530	indio_dev->pollfunc)
	531	: 0;
	532	}
	533	EXPORT_SYMBOL(iio_triggered_ring_predisable);