[linux-2.6-block.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);

/**
 * 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);
}

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;

	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:
	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);

	iio_trigger_unregister_sysfs(trig_info);
	ida_simple_remove(&iio_trigger_ida, trig_info->id);
	/* 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 */
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 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_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;
}

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 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 *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,
};

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 and associated but not attached triggers references */
	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_dettach_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
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	}
1637db44 JC	73
1637db44 JC	74	int iio_trigger_register(struct iio_trigger *trig_info)
	75	{
	76	int ret;
	77
47c24fdd JC	78	trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
	79	if (trig_info->id < 0) {
	80	ret = trig_info->id;
1637db44	81	goto error_ret;
47c24fdd	82	}
1637db44 JC	83	/* Set the name used for the sysfs directory etc */
	84	dev_set_name(&trig_info->dev, "trigger%ld",
	85	(unsigned long) trig_info->id);
	86
	87	ret = device_add(&trig_info->dev);
	88	if (ret)
	89	goto error_unregister_id;
	90
	91	ret = iio_trigger_register_sysfs(trig_info);
	92	if (ret)
	93	goto error_device_del;
	94
	95	/* Add to list of available triggers held by the IIO core */
	96	mutex_lock(&iio_trigger_list_lock);
	97	list_add_tail(&trig_info->list, &iio_trigger_list);
	98	mutex_unlock(&iio_trigger_list_lock);
	99
	100	return 0;
	101
	102	error_device_del:
	103	device_del(&trig_info->dev);
	104	error_unregister_id:
47c24fdd	105	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44 JC	106	error_ret:
	107	return ret;
	108	}
	109	EXPORT_SYMBOL(iio_trigger_register);
	110
	111	void iio_trigger_unregister(struct iio_trigger *trig_info)
	112	{
1637db44	113	mutex_lock(&iio_trigger_list_lock);
582e5489	114	list_del(&trig_info->list);
1637db44 JC	115	mutex_unlock(&iio_trigger_list_lock);
	116
	117	iio_trigger_unregister_sysfs(trig_info);
47c24fdd	118	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44 JC	119	/* Possible issue in here */
	120	device_unregister(&trig_info->dev);
	121	}
	122	EXPORT_SYMBOL(iio_trigger_unregister);
	123
f6517f22 JC	124	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	125	size_t len)
1637db44	126	{
f6517f22	127	struct iio_trigger trig = NULL, iter;
7c327857	128
1637db44	129	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	130	list_for_each_entry(iter, &iio_trigger_list, list)
	131	if (sysfs_streq(iter->name, name)) {
	132	trig = iter;
1637db44 JC	133	break;
1637db44 JC	134	}
1637db44 JC	135	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	136
f6517f22	137	return trig;
5f87404d	138	}
1637db44	139
7b2c33b1	140	void iio_trigger_poll(struct iio_trigger *trig, s64 time)
1637db44	141	{
d96d1337	142	int i;
cb6c89a0	143	if (!trig->use_count)
d96d1337 JC	144	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	145	if (trig->subirqs[i].enabled) {
	146	trig->use_count++;
	147	generic_handle_irq(trig->subirq_base + i);
	148	}
1637db44 JC	149	}
1637db44 JC	150	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	151
	152	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	153	{
	154	iio_trigger_poll(private, iio_get_time_ns());
	155	return IRQ_HANDLED;
	156	}
	157	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	158
1f785681 JC	159	void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
	160	{
	161	int i;
e69616b1	162	if (!trig->use_count)
1f785681 JC	163	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	164	if (trig->subirqs[i].enabled) {
	165	trig->use_count++;
	166	handle_nested_irq(trig->subirq_base + i);
	167	}
1f785681 JC	168	}
	169	EXPORT_SYMBOL(iio_trigger_poll_chained);
	170
1637db44 JC	171	void iio_trigger_notify_done(struct iio_trigger *trig)
	172	{
	173	trig->use_count--;
d29f73db	174	if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
e69616b1	175	if (trig->ops->try_reenable(trig))
1637db44	176	/* Missed and interrupt so launch new poll now */
7b2c33b1	177	iio_trigger_poll(trig, 0);
1637db44 JC	178	}
	179	EXPORT_SYMBOL(iio_trigger_notify_done);
	180
1637db44	181	/* Trigger Consumer related functions */
208b813c JC	182	static int iio_trigger_get_irq(struct iio_trigger *trig)
	183	{
	184	int ret;
	185	mutex_lock(&trig->pool_lock);
	186	ret = bitmap_find_free_region(trig->pool,
	187	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	188	ilog2(1));
	189	mutex_unlock(&trig->pool_lock);
	190	if (ret >= 0)
	191	ret += trig->subirq_base;
	192
	193	return ret;
	194	}
	195
	196	static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
	197	{
	198	mutex_lock(&trig->pool_lock);
	199	clear_bit(irq - trig->subirq_base, trig->pool);
	200	mutex_unlock(&trig->pool_lock);
	201	}
1637db44 JC	202
	203	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	204	* may be needed if the pollfuncs do not include the data read for the
	205	* triggering device.
	206	* This is not currently handled. Alternative of not enabling trigger unless
	207	* the relevant function is in there may be the best option.
	208	*/
	209	/* Worth protecting against double additions?*/
208b813c JC	210	static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
208b813c JC	211	struct iio_poll_func *pf)
1637db44 JC	212	{
1637db44 JC	213	int ret = 0;
51c060a0 JC	214	bool notinuse
	215	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	216
f60c4a02 JC	217	/* Prevent the module being removed whilst attached to a trigger */
f60c4a02 JC	218	__module_get(pf->indio_dev->info->driver_module);
51c060a0 JC	219	pf->irq = iio_trigger_get_irq(trig);
	220	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	221	pf->type, pf->name,
	222	pf);
5dd72ecb JC	223	if (ret < 0) {
	224	module_put(pf->indio_dev->info->driver_module);
	225	return ret;
	226	}
	227
	228	if (trig->ops && trig->ops->set_trigger_state && notinuse) {
d29f73db	229	ret = trig->ops->set_trigger_state(trig, true);
5dd72ecb JC	230	if (ret < 0)
	231	module_put(pf->indio_dev->info->driver_module);
	232	}
d96d1337	233
1637db44 JC	234	return ret;
1637db44 JC	235	}
1637db44	236
208b813c JC	237	static int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
208b813c JC	238	struct iio_poll_func *pf)
1637db44	239	{
51c060a0 JC	240	int ret = 0;
	241	bool no_other_users
	242	= (bitmap_weight(trig->pool,
	243	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	244	== 1);
d29f73db JC	245	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
d29f73db JC	246	ret = trig->ops->set_trigger_state(trig, false);
51c060a0 JC	247	if (ret)
51c060a0 JC	248	goto error_ret;
1637db44	249	}
51c060a0 JC	250	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	251	free_irq(pf->irq, pf);
f60c4a02	252	module_put(pf->indio_dev->info->driver_module);
1637db44 JC	253
	254	error_ret:
	255	return ret;
	256	}
1637db44	257
d96d1337 JC	258	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	259	{
	260	struct iio_poll_func *pf = p;
	261	pf->timestamp = iio_get_time_ns();
	262	return IRQ_WAKE_THREAD;
	263	}
	264	EXPORT_SYMBOL(iio_pollfunc_store_time);
	265
21b185f8 JC	266	struct iio_poll_func
	267	iio_alloc_pollfunc(irqreturn_t (h)(int irq, void *p),
	268	irqreturn_t (thread)(int irq, void p),
	269	int type,
e65bc6ac	270	struct iio_dev *indio_dev,
21b185f8 JC	271	const char *fmt,
	272	...)
	273	{
	274	va_list vargs;
	275	struct iio_poll_func *pf;
	276
	277	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	278	if (pf == NULL)
	279	return NULL;
	280	va_start(vargs, fmt);
	281	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	282	va_end(vargs);
	283	if (pf->name == NULL) {
	284	kfree(pf);
	285	return NULL;
	286	}
	287	pf->h = h;
	288	pf->thread = thread;
	289	pf->type = type;
e65bc6ac	290	pf->indio_dev = indio_dev;
21b185f8 JC	291
	292	return pf;
	293	}
	294	EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
	295
	296	void iio_dealloc_pollfunc(struct iio_poll_func *pf)
	297	{
	298	kfree(pf->name);
	299	kfree(pf);
	300	}
	301	EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
	302
1637db44	303	/**
42b2aa86	304	* iio_trigger_read_current() - trigger consumer sysfs query which trigger
1637db44 JC	305	*
	306	* For trigger consumers the current_trigger interface allows the trigger
	307	* used by the device to be queried.
	308	**/
	309	static ssize_t iio_trigger_read_current(struct device *dev,
	310	struct device_attribute *attr,
	311	char *buf)
	312	{
e53f5ac5	313	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
cb6c89a0	314
f8c6f4e9 JC	315	if (indio_dev->trig)
f8c6f4e9 JC	316	return sprintf(buf, "%s\n", indio_dev->trig->name);
cb6c89a0	317	return 0;
1637db44 JC	318	}
	319
	320	/**
	321	* iio_trigger_write_current() trigger consumer sysfs set current trigger
	322	*
	323	* For trigger consumers the current_trigger interface allows the trigger
	324	* used for this device to be specified at run time based on the triggers
	325	* name.
	326	**/
	327	static ssize_t iio_trigger_write_current(struct device *dev,
	328	struct device_attribute *attr,
	329	const char *buf,
	330	size_t len)
	331	{
e53f5ac5	332	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
f8c6f4e9	333	struct iio_trigger *oldtrig = indio_dev->trig;
43a4360e MH	334	struct iio_trigger *trig;
	335	int ret;
	336
f8c6f4e9 JC	337	mutex_lock(&indio_dev->mlock);
	338	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
	339	mutex_unlock(&indio_dev->mlock);
1637db44 JC	340	return -EBUSY;
1637db44 JC	341	}
f8c6f4e9	342	mutex_unlock(&indio_dev->mlock);
1637db44	343
43a4360e	344	trig = iio_trigger_find_by_name(buf, len);
5dd72ecb JC	345	if (oldtrig == trig)
5dd72ecb JC	346	return len;
43a4360e	347
f8c6f4e9 JC	348	if (trig && indio_dev->info->validate_trigger) {
f8c6f4e9 JC	349	ret = indio_dev->info->validate_trigger(indio_dev, trig);
43a4360e MH	350	if (ret)
	351	return ret;
	352	}
	353
d29f73db	354	if (trig && trig->ops && trig->ops->validate_device) {
f8c6f4e9	355	ret = trig->ops->validate_device(trig, indio_dev);
43a4360e MH	356	if (ret)
	357	return ret;
	358	}
	359
f8c6f4e9	360	indio_dev->trig = trig;
43a4360e	361
f8c6f4e9	362	if (oldtrig && indio_dev->trig != oldtrig)
7cbb7537	363	iio_trigger_put(oldtrig);
f8c6f4e9	364	if (indio_dev->trig)
7cbb7537	365	iio_trigger_get(indio_dev->trig);
1637db44 JC	366
	367	return len;
	368	}
	369
74112d3f GKH	370	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	371	iio_trigger_read_current,
	372	iio_trigger_write_current);
1637db44 JC	373
	374	static struct attribute *iio_trigger_consumer_attrs[] = {
	375	&dev_attr_current_trigger.attr,
	376	NULL,
	377	};
	378
	379	static const struct attribute_group iio_trigger_consumer_attr_group = {
	380	.name = "trigger",
	381	.attrs = iio_trigger_consumer_attrs,
	382	};
	383
	384	static void iio_trig_release(struct device *device)
	385	{
	386	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	387	int i;
	388
	389	if (trig->subirq_base) {
	390	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	391	irq_modify_status(trig->subirq_base + i,
	392	IRQ_NOAUTOEN,
	393	IRQ_NOREQUEST \| IRQ_NOPROBE);
	394	irq_set_chip(trig->subirq_base + i,
	395	NULL);
	396	irq_set_handler(trig->subirq_base + i,
	397	NULL);
	398	}
	399
	400	irq_free_descs(trig->subirq_base,
	401	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	402	}
59c85e82	403	kfree(trig->name);
1637db44	404	kfree(trig);
1637db44 JC	405	}
	406
	407	static struct device_type iio_trig_type = {
	408	.release = iio_trig_release,
	409	};
	410
d96d1337 JC	411	static void iio_trig_subirqmask(struct irq_data *d)
	412	{
	413	struct irq_chip *chip = irq_data_get_irq_chip(d);
	414	struct iio_trigger *trig
	415	= container_of(chip,
	416	struct iio_trigger, subirq_chip);
	417	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	418	}
	419
	420	static void iio_trig_subirqunmask(struct irq_data *d)
	421	{
	422	struct irq_chip *chip = irq_data_get_irq_chip(d);
	423	struct iio_trigger *trig
	424	= container_of(chip,
	425	struct iio_trigger, subirq_chip);
	426	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	427	}
	428
7cbb7537	429	struct iio_trigger iio_trigger_alloc(const char fmt, ...)
1637db44	430	{
59c85e82	431	va_list vargs;
1637db44 JC	432	struct iio_trigger *trig;
	433	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	434	if (trig) {
d96d1337	435	int i;
1637db44	436	trig->dev.type = &iio_trig_type;
5aaaeba8	437	trig->dev.bus = &iio_bus_type;
1637db44	438	device_initialize(&trig->dev);
d96d1337	439
59c85e82 JC	440	mutex_init(&trig->pool_lock);
	441	trig->subirq_base
	442	= irq_alloc_descs(-1, 0,
	443	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	444	0);
	445	if (trig->subirq_base < 0) {
	446	kfree(trig);
	447	return NULL;
	448	}
	449	va_start(vargs, fmt);
	450	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	451	va_end(vargs);
	452	if (trig->name == NULL) {
	453	irq_free_descs(trig->subirq_base,
	454	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	455	kfree(trig);
	456	return NULL;
	457	}
	458	trig->subirq_chip.name = trig->name;
	459	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	460	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	461	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	462	irq_set_chip(trig->subirq_base + i,
	463	&trig->subirq_chip);
	464	irq_set_handler(trig->subirq_base + i,
	465	&handle_simple_irq);
	466	irq_modify_status(trig->subirq_base + i,
	467	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	468	IRQ_NOPROBE);
d96d1337	469	}
5f9c035c	470	get_device(&trig->dev);
1637db44 JC	471	}
	472	return trig;
	473	}
7cbb7537	474	EXPORT_SYMBOL(iio_trigger_alloc);
1637db44	475
7cbb7537	476	void iio_trigger_free(struct iio_trigger *trig)
1637db44 JC	477	{
	478	if (trig)
	479	put_device(&trig->dev);
	480	}
7cbb7537	481	EXPORT_SYMBOL(iio_trigger_free);
1637db44	482
67be8e32	483	void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
1637db44	484	{
f8c6f4e9	485	indio_dev->groups[indio_dev->groupcounter++] =
26d25ae3	486	&iio_trigger_consumer_attr_group;
1637db44	487	}
1637db44	488
f8c6f4e9	489	void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
1637db44	490	{
5f9c035c	491	/* Clean up and associated but not attached triggers references */
f8c6f4e9	492	if (indio_dev->trig)
7cbb7537	493	iio_trigger_put(indio_dev->trig);
1637db44	494	}
1637db44	495
3b99fb76	496	int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
c3db00cc	497	{
67be8e32 JC	498	return iio_trigger_attach_poll_func(indio_dev->trig,
67be8e32 JC	499	indio_dev->pollfunc);
c3db00cc	500	}
3b99fb76	501	EXPORT_SYMBOL(iio_triggered_buffer_postenable);
c3db00cc	502
3b99fb76	503	int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
c3db00cc	504	{
67be8e32 JC	505	return iio_trigger_dettach_poll_func(indio_dev->trig,
67be8e32 JC	506	indio_dev->pollfunc);
c3db00cc	507	}
3b99fb76	508	EXPORT_SYMBOL(iio_triggered_buffer_predisable);