[mirror_ubuntu-hirsute-kernel.git] / drivers / 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 <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include "iio_core.h"
#include "iio_core_trigger.h"
#include <linux/iio/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_IDA(iio_trigger_ida);

/* 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 = to_iio_trigger(dev);
	return sprintf(buf, "%s\n", trig->name);
}

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

static struct attribute *iio_trig_dev_attrs[] = {
	&dev_attr_name.attr,
	NULL,
};

static struct attribute_group iio_trig_attr_group = {
	.attrs	= iio_trig_dev_attrs,
};

static const struct attribute_group *iio_trig_attr_groups[] = {
	&iio_trig_attr_group,
	NULL
};

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

	trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
	if (trig_info->id < 0) {
		ret = trig_info->id;
		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;

	/* 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_unregister_id:
	ida_simple_remove(&iio_trigger_ida, trig_info->id);
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);

	ida_simple_remove(&iio_trigger_ida, trig_info->id);
	/* Possible issue in here */
	device_del(&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 an interrupt so launch new poll now */
			iio_trigger_poll(trig, 0);
}
EXPORT_SYMBOL(iio_trigger_notify_done);

/* Trigger Consumer related functions */
static int iio_trigger_get_irq(struct iio_trigger *trig)
{
	int ret;
	mutex_lock(&trig->pool_lock);
	ret = bitmap_find_free_region(trig->pool,
				      CONFIG_IIO_CONSUMERS_PER_TRIGGER,
				      ilog2(1));
	mutex_unlock(&trig->pool_lock);
	if (ret >= 0)
		ret += trig->subirq_base;

	return ret;
}

static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
{
	mutex_lock(&trig->pool_lock);
	clear_bit(irq - trig->subirq_base, trig->pool);
	mutex_unlock(&trig->pool_lock);
}

/* 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? */
static 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 from 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 (ret < 0) {
		module_put(pf->indio_dev->info->driver_module);
		return ret;
	}

	if (trig->ops && trig->ops->set_trigger_state && notinuse) {
		ret = trig->ops->set_trigger_state(trig, true);
		if (ret < 0)
			module_put(pf->indio_dev->info->driver_module);
	}

	return ret;
}

static int iio_trigger_detach_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;
}

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_current() - trigger consumer sysfs query current 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 *indio_dev = dev_to_iio_dev(dev);

	if (indio_dev->trig)
		return sprintf(buf, "%s\n", indio_dev->trig->name);
	return 0;
}

/**
 * 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 *indio_dev = dev_to_iio_dev(dev);
	struct iio_trigger *oldtrig = indio_dev->trig;
	struct iio_trigger *trig;
	int ret;

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

	trig = iio_trigger_find_by_name(buf, len);
	if (oldtrig == trig)
		return len;

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

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

	indio_dev->trig = trig;

	if (oldtrig && indio_dev->trig != oldtrig)
		iio_trigger_put(oldtrig);
	if (indio_dev->trig)
		iio_trigger_get(indio_dev->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);
}

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

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_trigger_alloc(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);

		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);
		}
		get_device(&trig->dev);
	}
	return trig;
}
EXPORT_SYMBOL(iio_trigger_alloc);

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

void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
{
	indio_dev->groups[indio_dev->groupcounter++] =
		&iio_trigger_consumer_attr_group;
}

void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
{
	/* Clean up an associated but not attached trigger reference */
	if (indio_dev->trig)
		iio_trigger_put(indio_dev->trig);
}

int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
{
	return iio_trigger_attach_poll_func(indio_dev->trig,
					    indio_dev->pollfunc);
}
EXPORT_SYMBOL(iio_triggered_buffer_postenable);

int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
{
	return iio_trigger_detach_poll_func(indio_dev->trig,
					     indio_dev->pollfunc);
}
EXPORT_SYMBOL(iio_triggered_buffer_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	17
06458e27 JC	18	#include <linux/iio/iio.h>
06458e27 JC	19	#include <linux/iio/trigger.h>
df9c1c42	20	#include "iio_core.h"
6aea1c36	21	#include "iio_core_trigger.h"
06458e27	22	#include <linux/iio/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
47c24fdd	35	static DEFINE_IDA(iio_trigger_ida);
1637db44 JC	36
	37	/* Single list of all available triggers */
	38	static LIST_HEAD(iio_trigger_list);
	39	static DEFINE_MUTEX(iio_trigger_list_lock);
	40
59c85e82 JC	41	/**
	42	* iio_trigger_read_name() - retrieve useful identifying name
	43	**/
	44	static ssize_t iio_trigger_read_name(struct device *dev,
	45	struct device_attribute *attr,
	46	char *buf)
	47	{
971ff1db	48	struct iio_trigger *trig = to_iio_trigger(dev);
59c85e82 JC	49	return sprintf(buf, "%s\n", trig->name);
	50	}
	51
	52	static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
	53
6d459aa0 LPC	54	static struct attribute *iio_trig_dev_attrs[] = {
	55	&dev_attr_name.attr,
	56	NULL,
	57	};
1637db44	58
6d459aa0 LPC	59	static struct attribute_group iio_trig_attr_group = {
	60	.attrs = iio_trig_dev_attrs,
	61	};
	62
	63	static const struct attribute_group *iio_trig_attr_groups[] = {
	64	&iio_trig_attr_group,
	65	NULL
	66	};
1637db44	67
1637db44 JC	68	int iio_trigger_register(struct iio_trigger *trig_info)
	69	{
	70	int ret;
	71
47c24fdd JC	72	trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
	73	if (trig_info->id < 0) {
	74	ret = trig_info->id;
1637db44	75	goto error_ret;
47c24fdd	76	}
1637db44 JC	77	/* Set the name used for the sysfs directory etc */
	78	dev_set_name(&trig_info->dev, "trigger%ld",
	79	(unsigned long) trig_info->id);
	80
	81	ret = device_add(&trig_info->dev);
	82	if (ret)
	83	goto error_unregister_id;
	84
1637db44 JC	85	/* Add to list of available triggers held by the IIO core */
	86	mutex_lock(&iio_trigger_list_lock);
	87	list_add_tail(&trig_info->list, &iio_trigger_list);
	88	mutex_unlock(&iio_trigger_list_lock);
	89
	90	return 0;
	91
1637db44	92	error_unregister_id:
47c24fdd	93	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44 JC	94	error_ret:
	95	return ret;
	96	}
	97	EXPORT_SYMBOL(iio_trigger_register);
	98
	99	void iio_trigger_unregister(struct iio_trigger *trig_info)
	100	{
1637db44	101	mutex_lock(&iio_trigger_list_lock);
582e5489	102	list_del(&trig_info->list);
1637db44 JC	103	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	104
47c24fdd	105	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44	106	/* Possible issue in here */
8bade406	107	device_del(&trig_info->dev);
1637db44 JC	108	}
	109	EXPORT_SYMBOL(iio_trigger_unregister);
	110
f6517f22 JC	111	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	112	size_t len)
1637db44	113	{
f6517f22	114	struct iio_trigger trig = NULL, iter;
7c327857	115
1637db44	116	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	117	list_for_each_entry(iter, &iio_trigger_list, list)
	118	if (sysfs_streq(iter->name, name)) {
	119	trig = iter;
1637db44 JC	120	break;
1637db44 JC	121	}
1637db44 JC	122	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	123
f6517f22	124	return trig;
5f87404d	125	}
1637db44	126
7b2c33b1	127	void iio_trigger_poll(struct iio_trigger *trig, s64 time)
1637db44	128	{
d96d1337	129	int i;
cb6c89a0	130	if (!trig->use_count)
d96d1337 JC	131	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	132	if (trig->subirqs[i].enabled) {
	133	trig->use_count++;
	134	generic_handle_irq(trig->subirq_base + i);
	135	}
1637db44 JC	136	}
1637db44 JC	137	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	138
	139	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	140	{
	141	iio_trigger_poll(private, iio_get_time_ns());
	142	return IRQ_HANDLED;
	143	}
	144	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	145
1f785681 JC	146	void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
	147	{
	148	int i;
e69616b1	149	if (!trig->use_count)
1f785681 JC	150	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	151	if (trig->subirqs[i].enabled) {
	152	trig->use_count++;
	153	handle_nested_irq(trig->subirq_base + i);
	154	}
1f785681 JC	155	}
	156	EXPORT_SYMBOL(iio_trigger_poll_chained);
	157
1637db44 JC	158	void iio_trigger_notify_done(struct iio_trigger *trig)
	159	{
	160	trig->use_count--;
d29f73db	161	if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
e69616b1	162	if (trig->ops->try_reenable(trig))
860c9c54	163	/* Missed an interrupt so launch new poll now */
7b2c33b1	164	iio_trigger_poll(trig, 0);
1637db44 JC	165	}
	166	EXPORT_SYMBOL(iio_trigger_notify_done);
	167
1637db44	168	/* Trigger Consumer related functions */
208b813c JC	169	static int iio_trigger_get_irq(struct iio_trigger *trig)
	170	{
	171	int ret;
	172	mutex_lock(&trig->pool_lock);
	173	ret = bitmap_find_free_region(trig->pool,
	174	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	175	ilog2(1));
	176	mutex_unlock(&trig->pool_lock);
	177	if (ret >= 0)
	178	ret += trig->subirq_base;
	179
	180	return ret;
	181	}
	182
	183	static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
	184	{
	185	mutex_lock(&trig->pool_lock);
	186	clear_bit(irq - trig->subirq_base, trig->pool);
	187	mutex_unlock(&trig->pool_lock);
	188	}
1637db44 JC	189
	190	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	191	* may be needed if the pollfuncs do not include the data read for the
	192	* triggering device.
	193	* This is not currently handled. Alternative of not enabling trigger unless
	194	* the relevant function is in there may be the best option.
	195	*/
860c9c54	196	/* Worth protecting against double additions? */
208b813c JC	197	static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
208b813c JC	198	struct iio_poll_func *pf)
1637db44 JC	199	{
1637db44 JC	200	int ret = 0;
51c060a0 JC	201	bool notinuse
	202	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	203
860c9c54	204	/* Prevent the module from being removed whilst attached to a trigger */
f60c4a02	205	__module_get(pf->indio_dev->info->driver_module);
51c060a0 JC	206	pf->irq = iio_trigger_get_irq(trig);
	207	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	208	pf->type, pf->name,
	209	pf);
5dd72ecb JC	210	if (ret < 0) {
	211	module_put(pf->indio_dev->info->driver_module);
	212	return ret;
	213	}
	214
	215	if (trig->ops && trig->ops->set_trigger_state && notinuse) {
d29f73db	216	ret = trig->ops->set_trigger_state(trig, true);
5dd72ecb JC	217	if (ret < 0)
	218	module_put(pf->indio_dev->info->driver_module);
	219	}
d96d1337	220
1637db44 JC	221	return ret;
1637db44 JC	222	}
1637db44	223
034bd7b5	224	static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
208b813c	225	struct iio_poll_func *pf)
1637db44	226	{
51c060a0 JC	227	int ret = 0;
	228	bool no_other_users
	229	= (bitmap_weight(trig->pool,
	230	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	231	== 1);
d29f73db JC	232	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
d29f73db JC	233	ret = trig->ops->set_trigger_state(trig, false);
51c060a0 JC	234	if (ret)
51c060a0 JC	235	goto error_ret;
1637db44	236	}
51c060a0 JC	237	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	238	free_irq(pf->irq, pf);
f60c4a02	239	module_put(pf->indio_dev->info->driver_module);
1637db44 JC	240
	241	error_ret:
	242	return ret;
	243	}
1637db44	244
d96d1337 JC	245	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	246	{
	247	struct iio_poll_func *pf = p;
	248	pf->timestamp = iio_get_time_ns();
	249	return IRQ_WAKE_THREAD;
	250	}
	251	EXPORT_SYMBOL(iio_pollfunc_store_time);
	252
21b185f8 JC	253	struct iio_poll_func
	254	iio_alloc_pollfunc(irqreturn_t (h)(int irq, void *p),
	255	irqreturn_t (thread)(int irq, void p),
	256	int type,
e65bc6ac	257	struct iio_dev *indio_dev,
21b185f8 JC	258	const char *fmt,
	259	...)
	260	{
	261	va_list vargs;
	262	struct iio_poll_func *pf;
	263
	264	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	265	if (pf == NULL)
	266	return NULL;
	267	va_start(vargs, fmt);
	268	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	269	va_end(vargs);
	270	if (pf->name == NULL) {
	271	kfree(pf);
	272	return NULL;
	273	}
	274	pf->h = h;
	275	pf->thread = thread;
	276	pf->type = type;
e65bc6ac	277	pf->indio_dev = indio_dev;
21b185f8 JC	278
	279	return pf;
	280	}
	281	EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
	282
	283	void iio_dealloc_pollfunc(struct iio_poll_func *pf)
	284	{
	285	kfree(pf->name);
	286	kfree(pf);
	287	}
	288	EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
	289
1637db44	290	/**
860c9c54	291	* iio_trigger_read_current() - trigger consumer sysfs query current trigger
1637db44 JC	292	*
	293	* For trigger consumers the current_trigger interface allows the trigger
	294	* used by the device to be queried.
	295	**/
	296	static ssize_t iio_trigger_read_current(struct device *dev,
	297	struct device_attribute *attr,
	298	char *buf)
	299	{
e53f5ac5	300	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
cb6c89a0	301
f8c6f4e9 JC	302	if (indio_dev->trig)
f8c6f4e9 JC	303	return sprintf(buf, "%s\n", indio_dev->trig->name);
cb6c89a0	304	return 0;
1637db44 JC	305	}
	306
	307	/**
860c9c54	308	* iio_trigger_write_current() - trigger consumer sysfs set current trigger
1637db44 JC	309	*
	310	* For trigger consumers the current_trigger interface allows the trigger
	311	* used for this device to be specified at run time based on the triggers
	312	* name.
	313	**/
	314	static ssize_t iio_trigger_write_current(struct device *dev,
	315	struct device_attribute *attr,
	316	const char *buf,
	317	size_t len)
	318	{
e53f5ac5	319	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
f8c6f4e9	320	struct iio_trigger *oldtrig = indio_dev->trig;
43a4360e MH	321	struct iio_trigger *trig;
	322	int ret;
	323
f8c6f4e9 JC	324	mutex_lock(&indio_dev->mlock);
	325	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
	326	mutex_unlock(&indio_dev->mlock);
1637db44 JC	327	return -EBUSY;
1637db44 JC	328	}
f8c6f4e9	329	mutex_unlock(&indio_dev->mlock);
1637db44	330
43a4360e	331	trig = iio_trigger_find_by_name(buf, len);
5dd72ecb JC	332	if (oldtrig == trig)
5dd72ecb JC	333	return len;
43a4360e	334
f8c6f4e9 JC	335	if (trig && indio_dev->info->validate_trigger) {
f8c6f4e9 JC	336	ret = indio_dev->info->validate_trigger(indio_dev, trig);
43a4360e MH	337	if (ret)
	338	return ret;
	339	}
	340
d29f73db	341	if (trig && trig->ops && trig->ops->validate_device) {
f8c6f4e9	342	ret = trig->ops->validate_device(trig, indio_dev);
43a4360e MH	343	if (ret)
	344	return ret;
	345	}
	346
f8c6f4e9	347	indio_dev->trig = trig;
43a4360e	348
f8c6f4e9	349	if (oldtrig && indio_dev->trig != oldtrig)
7cbb7537	350	iio_trigger_put(oldtrig);
f8c6f4e9	351	if (indio_dev->trig)
7cbb7537	352	iio_trigger_get(indio_dev->trig);
1637db44 JC	353
	354	return len;
	355	}
	356
74112d3f GKH	357	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	358	iio_trigger_read_current,
	359	iio_trigger_write_current);
1637db44 JC	360
	361	static struct attribute *iio_trigger_consumer_attrs[] = {
	362	&dev_attr_current_trigger.attr,
	363	NULL,
	364	};
	365
	366	static const struct attribute_group iio_trigger_consumer_attr_group = {
	367	.name = "trigger",
	368	.attrs = iio_trigger_consumer_attrs,
	369	};
	370
	371	static void iio_trig_release(struct device *device)
	372	{
	373	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	374	int i;
	375
	376	if (trig->subirq_base) {
	377	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	378	irq_modify_status(trig->subirq_base + i,
	379	IRQ_NOAUTOEN,
	380	IRQ_NOREQUEST \| IRQ_NOPROBE);
	381	irq_set_chip(trig->subirq_base + i,
	382	NULL);
	383	irq_set_handler(trig->subirq_base + i,
	384	NULL);
	385	}
	386
	387	irq_free_descs(trig->subirq_base,
	388	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	389	}
59c85e82	390	kfree(trig->name);
1637db44	391	kfree(trig);
1637db44 JC	392	}
	393
	394	static struct device_type iio_trig_type = {
	395	.release = iio_trig_release,
6d459aa0	396	.groups = iio_trig_attr_groups,
1637db44 JC	397	};
1637db44 JC	398
d96d1337 JC	399	static void iio_trig_subirqmask(struct irq_data *d)
	400	{
	401	struct irq_chip *chip = irq_data_get_irq_chip(d);
	402	struct iio_trigger *trig
	403	= container_of(chip,
	404	struct iio_trigger, subirq_chip);
	405	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	406	}
	407
	408	static void iio_trig_subirqunmask(struct irq_data *d)
	409	{
	410	struct irq_chip *chip = irq_data_get_irq_chip(d);
	411	struct iio_trigger *trig
	412	= container_of(chip,
	413	struct iio_trigger, subirq_chip);
	414	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	415	}
	416
7cbb7537	417	struct iio_trigger iio_trigger_alloc(const char fmt, ...)
1637db44	418	{
59c85e82	419	va_list vargs;
1637db44 JC	420	struct iio_trigger *trig;
	421	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	422	if (trig) {
d96d1337	423	int i;
1637db44	424	trig->dev.type = &iio_trig_type;
5aaaeba8	425	trig->dev.bus = &iio_bus_type;
1637db44	426	device_initialize(&trig->dev);
d96d1337	427
59c85e82 JC	428	mutex_init(&trig->pool_lock);
	429	trig->subirq_base
	430	= irq_alloc_descs(-1, 0,
	431	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	432	0);
	433	if (trig->subirq_base < 0) {
	434	kfree(trig);
	435	return NULL;
	436	}
	437	va_start(vargs, fmt);
	438	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	439	va_end(vargs);
	440	if (trig->name == NULL) {
	441	irq_free_descs(trig->subirq_base,
	442	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	443	kfree(trig);
	444	return NULL;
	445	}
	446	trig->subirq_chip.name = trig->name;
	447	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	448	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	449	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	450	irq_set_chip(trig->subirq_base + i,
	451	&trig->subirq_chip);
	452	irq_set_handler(trig->subirq_base + i,
	453	&handle_simple_irq);
	454	irq_modify_status(trig->subirq_base + i,
	455	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	456	IRQ_NOPROBE);
d96d1337	457	}
5f9c035c	458	get_device(&trig->dev);
1637db44 JC	459	}
	460	return trig;
	461	}
7cbb7537	462	EXPORT_SYMBOL(iio_trigger_alloc);
1637db44	463
7cbb7537	464	void iio_trigger_free(struct iio_trigger *trig)
1637db44 JC	465	{
	466	if (trig)
	467	put_device(&trig->dev);
	468	}
7cbb7537	469	EXPORT_SYMBOL(iio_trigger_free);
1637db44	470
67be8e32	471	void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
1637db44	472	{
f8c6f4e9	473	indio_dev->groups[indio_dev->groupcounter++] =
26d25ae3	474	&iio_trigger_consumer_attr_group;
1637db44	475	}
1637db44	476
f8c6f4e9	477	void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
1637db44	478	{
860c9c54	479	/* Clean up an associated but not attached trigger reference */
f8c6f4e9	480	if (indio_dev->trig)
7cbb7537	481	iio_trigger_put(indio_dev->trig);
1637db44	482	}
1637db44	483
3b99fb76	484	int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
c3db00cc	485	{
67be8e32 JC	486	return iio_trigger_attach_poll_func(indio_dev->trig,
67be8e32 JC	487	indio_dev->pollfunc);
c3db00cc	488	}
3b99fb76	489	EXPORT_SYMBOL(iio_triggered_buffer_postenable);
c3db00cc	490
3b99fb76	491	int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
c3db00cc	492	{
034bd7b5	493	return iio_trigger_detach_poll_func(indio_dev->trig,
67be8e32	494	indio_dev->pollfunc);
c3db00cc	495	}
3b99fb76	496	EXPORT_SYMBOL(iio_triggered_buffer_predisable);