[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/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_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->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);

/* 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);

struct iio_poll_func
*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
		    irqreturn_t (*thread)(int irq, void *p),
		    int type,
		    void *private,
		    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->private_data = private;

	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;
	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->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();
	}
	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);

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
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	{
	48	struct iio_trigger *trig = dev_get_drvdata(dev);
	49	return sprintf(buf, "%s\n", trig->name);
	50	}
	51
	52	static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
	53
1637db44 JC	54	/**
	55	* iio_trigger_register_sysfs() - create a device for this trigger
	56	* @trig_info: the trigger
	57	*
	58	* Also adds any control attribute registered by the trigger driver
	59	**/
	60	static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
	61	{
59c85e82 JC	62	return sysfs_add_file_to_group(&trig_info->dev.kobj,
	63	&dev_attr_name.attr,
	64	NULL);
1637db44 JC	65	}
	66
	67	static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
	68	{
59c85e82 JC	69	sysfs_remove_file_from_group(&trig_info->dev.kobj,
	70	&dev_attr_name.attr,
	71	NULL);
1637db44 JC	72	}
	73
	74
	75	/**
	76	* iio_trigger_register_id() - get a unique id for this trigger
	77	* @trig_info: the trigger
	78	**/
	79	static int iio_trigger_register_id(struct iio_trigger *trig_info)
	80	{
	81	int ret = 0;
	82
	83	idr_again:
	84	if (unlikely(idr_pre_get(&iio_trigger_idr, GFP_KERNEL) == 0))
	85	return -ENOMEM;
	86
	87	spin_lock(&iio_trigger_idr_lock);
	88	ret = idr_get_new(&iio_trigger_idr, NULL, &trig_info->id);
	89	spin_unlock(&iio_trigger_idr_lock);
	90	if (unlikely(ret == -EAGAIN))
	91	goto idr_again;
	92	else if (likely(!ret))
	93	trig_info->id = trig_info->id & MAX_ID_MASK;
	94
	95	return ret;
	96	}
	97
	98	/**
	99	* iio_trigger_unregister_id() - free up unique id for use by another trigger
	100	* @trig_info: the trigger
	101	**/
	102	static void iio_trigger_unregister_id(struct iio_trigger *trig_info)
	103	{
74112d3f GKH	104	spin_lock(&iio_trigger_idr_lock);
	105	idr_remove(&iio_trigger_idr, trig_info->id);
	106	spin_unlock(&iio_trigger_idr_lock);
1637db44 JC	107	}
	108
	109	int iio_trigger_register(struct iio_trigger *trig_info)
	110	{
	111	int ret;
	112
	113	ret = iio_trigger_register_id(trig_info);
	114	if (ret)
	115	goto error_ret;
	116	/* Set the name used for the sysfs directory etc */
	117	dev_set_name(&trig_info->dev, "trigger%ld",
	118	(unsigned long) trig_info->id);
	119
	120	ret = device_add(&trig_info->dev);
	121	if (ret)
	122	goto error_unregister_id;
	123
	124	ret = iio_trigger_register_sysfs(trig_info);
	125	if (ret)
	126	goto error_device_del;
	127
	128	/* Add to list of available triggers held by the IIO core */
	129	mutex_lock(&iio_trigger_list_lock);
	130	list_add_tail(&trig_info->list, &iio_trigger_list);
	131	mutex_unlock(&iio_trigger_list_lock);
	132
	133	return 0;
	134
	135	error_device_del:
	136	device_del(&trig_info->dev);
	137	error_unregister_id:
	138	iio_trigger_unregister_id(trig_info);
	139	error_ret:
	140	return ret;
	141	}
	142	EXPORT_SYMBOL(iio_trigger_register);
	143
	144	void iio_trigger_unregister(struct iio_trigger *trig_info)
	145	{
1637db44	146	mutex_lock(&iio_trigger_list_lock);
582e5489	147	list_del(&trig_info->list);
1637db44 JC	148	mutex_unlock(&iio_trigger_list_lock);
	149
	150	iio_trigger_unregister_sysfs(trig_info);
	151	iio_trigger_unregister_id(trig_info);
	152	/* Possible issue in here */
	153	device_unregister(&trig_info->dev);
	154	}
	155	EXPORT_SYMBOL(iio_trigger_unregister);
	156
f6517f22 JC	157	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	158	size_t len)
1637db44	159	{
f6517f22	160	struct iio_trigger trig = NULL, iter;
7c327857	161
1637db44	162	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	163	list_for_each_entry(iter, &iio_trigger_list, list)
	164	if (sysfs_streq(iter->name, name)) {
	165	trig = iter;
1637db44 JC	166	break;
1637db44 JC	167	}
1637db44 JC	168	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	169
f6517f22	170	return trig;
5f87404d	171	}
1637db44	172
7b2c33b1	173	void iio_trigger_poll(struct iio_trigger *trig, s64 time)
1637db44	174	{
d96d1337	175	int i;
d96d1337 JC	176	if (!trig->use_count) {
	177	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	178	if (trig->subirqs[i].enabled) {
	179	trig->use_count++;
	180	generic_handle_irq(trig->subirq_base + i);
	181	}
	182	}
1637db44 JC	183	}
1637db44 JC	184	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	185
	186	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	187	{
	188	iio_trigger_poll(private, iio_get_time_ns());
	189	return IRQ_HANDLED;
	190	}
	191	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	192
1f785681 JC	193	void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
	194	{
	195	int i;
	196	if (!trig->use_count) {
	197	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	198	if (trig->subirqs[i].enabled) {
	199	trig->use_count++;
	200	handle_nested_irq(trig->subirq_base + i);
	201	}
	202	}
	203	}
	204	EXPORT_SYMBOL(iio_trigger_poll_chained);
	205
1637db44 JC	206	void iio_trigger_notify_done(struct iio_trigger *trig)
	207	{
	208	trig->use_count--;
	209	if (trig->use_count == 0 && trig->try_reenable)
	210	if (trig->try_reenable(trig)) {
	211	/* Missed and interrupt so launch new poll now */
7b2c33b1	212	iio_trigger_poll(trig, 0);
1637db44 JC	213	}
	214	}
	215	EXPORT_SYMBOL(iio_trigger_notify_done);
	216
1637db44 JC	217	/* Trigger Consumer related functions */
	218
	219	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	220	* may be needed if the pollfuncs do not include the data read for the
	221	* triggering device.
	222	* This is not currently handled. Alternative of not enabling trigger unless
	223	* the relevant function is in there may be the best option.
	224	*/
	225	/* Worth protecting against double additions?*/
	226	int iio_trigger_attach_poll_func(struct iio_trigger *trig,
	227	struct iio_poll_func *pf)
	228	{
	229	int ret = 0;
51c060a0 JC	230	bool notinuse
	231	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	232
	233	pf->irq = iio_trigger_get_irq(trig);
	234	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	235	pf->type, pf->name,
	236	pf);
	237	if (trig->set_trigger_state && notinuse)
	238	ret = trig->set_trigger_state(trig, true);
d96d1337	239
1637db44 JC	240	return ret;
	241	}
	242	EXPORT_SYMBOL(iio_trigger_attach_poll_func);
	243
	244	int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
	245	struct iio_poll_func *pf)
	246	{
51c060a0 JC	247	int ret = 0;
	248	bool no_other_users
	249	= (bitmap_weight(trig->pool,
	250	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	251	== 1);
	252	if (trig->set_trigger_state && no_other_users) {
	253	ret = trig->set_trigger_state(trig, false);
	254	if (ret)
	255	goto error_ret;
1637db44	256	}
51c060a0 JC	257	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	258	free_irq(pf->irq, pf);
1637db44 JC	259
	260	error_ret:
	261	return ret;
	262	}
	263	EXPORT_SYMBOL(iio_trigger_dettach_poll_func);
	264
d96d1337 JC	265	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	266	{
	267	struct iio_poll_func *pf = p;
	268	pf->timestamp = iio_get_time_ns();
	269	return IRQ_WAKE_THREAD;
	270	}
	271	EXPORT_SYMBOL(iio_pollfunc_store_time);
	272
21b185f8 JC	273	struct iio_poll_func
	274	iio_alloc_pollfunc(irqreturn_t (h)(int irq, void *p),
	275	irqreturn_t (thread)(int irq, void p),
	276	int type,
	277	void *private,
	278	const char *fmt,
	279	...)
	280	{
	281	va_list vargs;
	282	struct iio_poll_func *pf;
	283
	284	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	285	if (pf == NULL)
	286	return NULL;
	287	va_start(vargs, fmt);
	288	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	289	va_end(vargs);
	290	if (pf->name == NULL) {
	291	kfree(pf);
	292	return NULL;
	293	}
	294	pf->h = h;
	295	pf->thread = thread;
	296	pf->type = type;
c11c4eeb	297	pf->private_data = private;
21b185f8 JC	298
	299	return pf;
	300	}
	301	EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
	302
	303	void iio_dealloc_pollfunc(struct iio_poll_func *pf)
	304	{
	305	kfree(pf->name);
	306	kfree(pf);
	307	}
	308	EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
	309
1637db44	310	/**
751a3700	311	* iio_trigger_read_currrent() - trigger consumer sysfs query which trigger
1637db44 JC	312	*
	313	* For trigger consumers the current_trigger interface allows the trigger
	314	* used by the device to be queried.
	315	**/
	316	static ssize_t iio_trigger_read_current(struct device *dev,
	317	struct device_attribute *attr,
	318	char *buf)
	319	{
	320	struct iio_dev *dev_info = dev_get_drvdata(dev);
	321	int len = 0;
	322	if (dev_info->trig)
3c9bbf58 JC	323	len = sprintf(buf,
	324	"%s\n",
	325	dev_info->trig->name);
1637db44 JC	326	return len;
	327	}
	328
	329	/**
	330	* iio_trigger_write_current() trigger consumer sysfs set current trigger
	331	*
	332	* For trigger consumers the current_trigger interface allows the trigger
	333	* used for this device to be specified at run time based on the triggers
	334	* name.
	335	**/
	336	static ssize_t iio_trigger_write_current(struct device *dev,
	337	struct device_attribute *attr,
	338	const char *buf,
	339	size_t len)
	340	{
	341	struct iio_dev *dev_info = dev_get_drvdata(dev);
	342	struct iio_trigger *oldtrig = dev_info->trig;
	343	mutex_lock(&dev_info->mlock);
	344	if (dev_info->currentmode == INDIO_RING_TRIGGERED) {
	345	mutex_unlock(&dev_info->mlock);
	346	return -EBUSY;
	347	}
	348	mutex_unlock(&dev_info->mlock);
	349
1637db44 JC	350	dev_info->trig = iio_trigger_find_by_name(buf, len);
	351	if (oldtrig && dev_info->trig != oldtrig)
	352	iio_put_trigger(oldtrig);
	353	if (dev_info->trig)
	354	iio_get_trigger(dev_info->trig);
	355
	356	return len;
	357	}
	358
74112d3f GKH	359	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	360	iio_trigger_read_current,
	361	iio_trigger_write_current);
1637db44 JC	362
	363	static struct attribute *iio_trigger_consumer_attrs[] = {
	364	&dev_attr_current_trigger.attr,
	365	NULL,
	366	};
	367
	368	static const struct attribute_group iio_trigger_consumer_attr_group = {
	369	.name = "trigger",
	370	.attrs = iio_trigger_consumer_attrs,
	371	};
	372
	373	static void iio_trig_release(struct device *device)
	374	{
	375	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	376	int i;
	377
	378	if (trig->subirq_base) {
	379	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	380	irq_modify_status(trig->subirq_base + i,
	381	IRQ_NOAUTOEN,
	382	IRQ_NOREQUEST \| IRQ_NOPROBE);
	383	irq_set_chip(trig->subirq_base + i,
	384	NULL);
	385	irq_set_handler(trig->subirq_base + i,
	386	NULL);
	387	}
	388
	389	irq_free_descs(trig->subirq_base,
	390	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	391	}
59c85e82	392	kfree(trig->name);
1637db44 JC	393	kfree(trig);
	394	iio_put();
	395	}
	396
	397	static struct device_type iio_trig_type = {
	398	.release = iio_trig_release,
	399	};
	400
d96d1337 JC	401	static void iio_trig_subirqmask(struct irq_data *d)
	402	{
	403	struct irq_chip *chip = irq_data_get_irq_chip(d);
	404	struct iio_trigger *trig
	405	= container_of(chip,
	406	struct iio_trigger, subirq_chip);
	407	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	408	}
	409
	410	static void iio_trig_subirqunmask(struct irq_data *d)
	411	{
	412	struct irq_chip *chip = irq_data_get_irq_chip(d);
	413	struct iio_trigger *trig
	414	= container_of(chip,
	415	struct iio_trigger, subirq_chip);
	416	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	417	}
	418
59c85e82	419	struct iio_trigger iio_allocate_trigger(const char fmt, ...)
1637db44	420	{
59c85e82	421	va_list vargs;
1637db44 JC	422	struct iio_trigger *trig;
	423	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	424	if (trig) {
d96d1337	425	int i;
1637db44	426	trig->dev.type = &iio_trig_type;
5aaaeba8	427	trig->dev.bus = &iio_bus_type;
1637db44 JC	428	device_initialize(&trig->dev);
1637db44 JC	429	dev_set_drvdata(&trig->dev, (void *)trig);
d96d1337	430
59c85e82 JC	431	mutex_init(&trig->pool_lock);
	432	trig->subirq_base
	433	= irq_alloc_descs(-1, 0,
	434	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	435	0);
	436	if (trig->subirq_base < 0) {
	437	kfree(trig);
	438	return NULL;
	439	}
	440	va_start(vargs, fmt);
	441	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	442	va_end(vargs);
	443	if (trig->name == NULL) {
	444	irq_free_descs(trig->subirq_base,
	445	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	446	kfree(trig);
	447	return NULL;
	448	}
	449	trig->subirq_chip.name = trig->name;
	450	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	451	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	452	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	453	irq_set_chip(trig->subirq_base + i,
	454	&trig->subirq_chip);
	455	irq_set_handler(trig->subirq_base + i,
	456	&handle_simple_irq);
	457	irq_modify_status(trig->subirq_base + i,
	458	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	459	IRQ_NOPROBE);
d96d1337	460	}
1637db44 JC	461	iio_get();
	462	}
	463	return trig;
	464	}
	465	EXPORT_SYMBOL(iio_allocate_trigger);
	466
	467	void iio_free_trigger(struct iio_trigger *trig)
	468	{
	469	if (trig)
	470	put_device(&trig->dev);
	471	}
	472	EXPORT_SYMBOL(iio_free_trigger);
	473
	474	int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
	475	{
	476	int ret;
	477	ret = sysfs_create_group(&dev_info->dev.kobj,
	478	&iio_trigger_consumer_attr_group);
	479	return ret;
	480	}
	481	EXPORT_SYMBOL(iio_device_register_trigger_consumer);
	482
	483	int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
	484	{
	485	sysfs_remove_group(&dev_info->dev.kobj,
	486	&iio_trigger_consumer_attr_group);
	487	return 0;
	488	}
	489	EXPORT_SYMBOL(iio_device_unregister_trigger_consumer);
	490
c3db00cc JC	491	int iio_triggered_ring_postenable(struct iio_dev *indio_dev)
	492	{
	493	return indio_dev->trig
	494	? iio_trigger_attach_poll_func(indio_dev->trig,
	495	indio_dev->pollfunc)
	496	: 0;
	497	}
	498	EXPORT_SYMBOL(iio_triggered_ring_postenable);
	499
	500	int iio_triggered_ring_predisable(struct iio_dev *indio_dev)
	501	{
	502	return indio_dev->trig
	503	? iio_trigger_dettach_poll_func(indio_dev->trig,
	504	indio_dev->pollfunc)
	505	: 0;
	506	}
	507	EXPORT_SYMBOL(iio_triggered_ring_predisable);