[deliverable/linux.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,
};
ATTRIBUTE_GROUPS(iio_trig_dev);

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 (!atomic_read(&trig->use_count)) {
		atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);

		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
			if (trig->subirqs[i].enabled)
				generic_handle_irq(trig->subirq_base + i);
			else
				iio_trigger_notify_done(trig);
		}
	}
}
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 (!atomic_read(&trig->use_count)) {
		atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);

		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
			if (trig->subirqs[i].enabled)
				handle_nested_irq(trig->subirq_base + i);
			else
				iio_trigger_notify_done(trig);
		}
	}
}
EXPORT_SYMBOL(iio_trigger_poll_chained);

void iio_trigger_notify_done(struct iio_trigger *trig)
{
	if (atomic_dec_and_test(&trig->use_count) && 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 trigger's
 * 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)
		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_dev_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;
}

static struct iio_trigger *viio_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;
		}

		trig->name = kvasprintf(GFP_KERNEL, fmt, 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;
}

struct iio_trigger *iio_trigger_alloc(const char *fmt, ...)
{
	struct iio_trigger *trig;
	va_list vargs;

	va_start(vargs, fmt);
	trig = viio_trigger_alloc(fmt, vargs);
	va_end(vargs);

	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);

static void devm_iio_trigger_release(struct device *dev, void *res)
{
	iio_trigger_free(*(struct iio_trigger **)res);
}

static int devm_iio_trigger_match(struct device *dev, void *res, void *data)
{
	struct iio_trigger **r = res;

	if (!r || !*r) {
		WARN_ON(!r || !*r);
		return 0;
	}

	return *r == data;
}

/**
 * devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
 * @dev:		Device to allocate iio_trigger for
 * @fmt:		trigger name format. If it includes format
 *			specifiers, the additional arguments following
 *			format are formatted and inserted in the resulting
 *			string replacing their respective specifiers.
 *
 * Managed iio_trigger_alloc.  iio_trigger allocated with this function is
 * automatically freed on driver detach.
 *
 * If an iio_trigger allocated with this function needs to be freed separately,
 * devm_iio_trigger_free() must be used.
 *
 * RETURNS:
 * Pointer to allocated iio_trigger on success, NULL on failure.
 */
struct iio_trigger *devm_iio_trigger_alloc(struct device *dev,
						const char *fmt, ...)
{
	struct iio_trigger **ptr, *trig;
	va_list vargs;

	ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
			   GFP_KERNEL);
	if (!ptr)
		return NULL;

	/* use raw alloc_dr for kmalloc caller tracing */
	va_start(vargs, fmt);
	trig = viio_trigger_alloc(fmt, vargs);
	va_end(vargs);
	if (trig) {
		*ptr = trig;
		devres_add(dev, ptr);
	} else {
		devres_free(ptr);
	}

	return trig;
}
EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);

/**
 * devm_iio_trigger_free - Resource-managed iio_trigger_free()
 * @dev:		Device this iio_dev belongs to
 * @iio_trig:		the iio_trigger associated with the device
 *
 * Free iio_trigger allocated with devm_iio_trigger_alloc().
 */
void devm_iio_trigger_free(struct device *dev, struct iio_trigger *iio_trig)
{
	int rc;

	rc = devres_release(dev, devm_iio_trigger_release,
			    devm_iio_trigger_match, iio_trig);
	WARN_ON(rc);
}
EXPORT_SYMBOL_GPL(devm_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	};
f59c2576	58	ATTRIBUTE_GROUPS(iio_trig_dev);
1637db44	59
1637db44 JC	60	int iio_trigger_register(struct iio_trigger *trig_info)
	61	{
	62	int ret;
	63
47c24fdd JC	64	trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
	65	if (trig_info->id < 0) {
	66	ret = trig_info->id;
1637db44	67	goto error_ret;
47c24fdd	68	}
1637db44 JC	69	/* Set the name used for the sysfs directory etc */
	70	dev_set_name(&trig_info->dev, "trigger%ld",
	71	(unsigned long) trig_info->id);
	72
	73	ret = device_add(&trig_info->dev);
	74	if (ret)
	75	goto error_unregister_id;
	76
1637db44 JC	77	/* Add to list of available triggers held by the IIO core */
	78	mutex_lock(&iio_trigger_list_lock);
	79	list_add_tail(&trig_info->list, &iio_trigger_list);
	80	mutex_unlock(&iio_trigger_list_lock);
	81
	82	return 0;
	83
1637db44	84	error_unregister_id:
47c24fdd	85	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44 JC	86	error_ret:
	87	return ret;
	88	}
	89	EXPORT_SYMBOL(iio_trigger_register);
	90
	91	void iio_trigger_unregister(struct iio_trigger *trig_info)
	92	{
1637db44	93	mutex_lock(&iio_trigger_list_lock);
582e5489	94	list_del(&trig_info->list);
1637db44 JC	95	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	96
47c24fdd	97	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44	98	/* Possible issue in here */
8bade406	99	device_del(&trig_info->dev);
1637db44 JC	100	}
	101	EXPORT_SYMBOL(iio_trigger_unregister);
	102
f6517f22 JC	103	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	104	size_t len)
1637db44	105	{
f6517f22	106	struct iio_trigger trig = NULL, iter;
7c327857	107
1637db44	108	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	109	list_for_each_entry(iter, &iio_trigger_list, list)
	110	if (sysfs_streq(iter->name, name)) {
	111	trig = iter;
1637db44 JC	112	break;
1637db44 JC	113	}
1637db44 JC	114	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	115
f6517f22	116	return trig;
5f87404d	117	}
1637db44	118
7b2c33b1	119	void iio_trigger_poll(struct iio_trigger *trig, s64 time)
1637db44	120	{
d96d1337	121	int i;
a1a8e1dc LPC	122
	123	if (!atomic_read(&trig->use_count)) {
	124	atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	125
	126	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	127	if (trig->subirqs[i].enabled)
d96d1337	128	generic_handle_irq(trig->subirq_base + i);
a1a8e1dc LPC	129	else
	130	iio_trigger_notify_done(trig);
	131	}
	132	}
1637db44 JC	133	}
1637db44 JC	134	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	135
	136	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	137	{
	138	iio_trigger_poll(private, iio_get_time_ns());
	139	return IRQ_HANDLED;
	140	}
	141	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	142
1f785681 JC	143	void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
	144	{
	145	int i;
a1a8e1dc LPC	146
	147	if (!atomic_read(&trig->use_count)) {
	148	atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	149
	150	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	151	if (trig->subirqs[i].enabled)
1f785681	152	handle_nested_irq(trig->subirq_base + i);
a1a8e1dc LPC	153	else
	154	iio_trigger_notify_done(trig);
	155	}
	156	}
1f785681 JC	157	}
	158	EXPORT_SYMBOL(iio_trigger_poll_chained);
	159
1637db44 JC	160	void iio_trigger_notify_done(struct iio_trigger *trig)
1637db44 JC	161	{
a1a8e1dc LPC	162	if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
a1a8e1dc LPC	163	trig->ops->try_reenable)
e69616b1	164	if (trig->ops->try_reenable(trig))
860c9c54	165	/* Missed an interrupt so launch new poll now */
7b2c33b1	166	iio_trigger_poll(trig, 0);
1637db44 JC	167	}
	168	EXPORT_SYMBOL(iio_trigger_notify_done);
	169
1637db44	170	/* Trigger Consumer related functions */
208b813c JC	171	static int iio_trigger_get_irq(struct iio_trigger *trig)
	172	{
	173	int ret;
	174	mutex_lock(&trig->pool_lock);
	175	ret = bitmap_find_free_region(trig->pool,
	176	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	177	ilog2(1));
	178	mutex_unlock(&trig->pool_lock);
	179	if (ret >= 0)
	180	ret += trig->subirq_base;
	181
	182	return ret;
	183	}
	184
	185	static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
	186	{
	187	mutex_lock(&trig->pool_lock);
	188	clear_bit(irq - trig->subirq_base, trig->pool);
	189	mutex_unlock(&trig->pool_lock);
	190	}
1637db44 JC	191
	192	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	193	* may be needed if the pollfuncs do not include the data read for the
	194	* triggering device.
	195	* This is not currently handled. Alternative of not enabling trigger unless
	196	* the relevant function is in there may be the best option.
	197	*/
860c9c54	198	/* Worth protecting against double additions? */
208b813c JC	199	static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
208b813c JC	200	struct iio_poll_func *pf)
1637db44 JC	201	{
1637db44 JC	202	int ret = 0;
51c060a0 JC	203	bool notinuse
	204	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	205
860c9c54	206	/* Prevent the module from being removed whilst attached to a trigger */
f60c4a02	207	__module_get(pf->indio_dev->info->driver_module);
51c060a0 JC	208	pf->irq = iio_trigger_get_irq(trig);
	209	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	210	pf->type, pf->name,
	211	pf);
5dd72ecb JC	212	if (ret < 0) {
	213	module_put(pf->indio_dev->info->driver_module);
	214	return ret;
	215	}
	216
	217	if (trig->ops && trig->ops->set_trigger_state && notinuse) {
d29f73db	218	ret = trig->ops->set_trigger_state(trig, true);
5dd72ecb JC	219	if (ret < 0)
	220	module_put(pf->indio_dev->info->driver_module);
	221	}
d96d1337	222
1637db44 JC	223	return ret;
1637db44 JC	224	}
1637db44	225
034bd7b5	226	static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
208b813c	227	struct iio_poll_func *pf)
1637db44	228	{
51c060a0 JC	229	int ret = 0;
	230	bool no_other_users
	231	= (bitmap_weight(trig->pool,
	232	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	233	== 1);
d29f73db JC	234	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
d29f73db JC	235	ret = trig->ops->set_trigger_state(trig, false);
51c060a0 JC	236	if (ret)
51c060a0 JC	237	goto error_ret;
1637db44	238	}
51c060a0 JC	239	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	240	free_irq(pf->irq, pf);
f60c4a02	241	module_put(pf->indio_dev->info->driver_module);
1637db44 JC	242
	243	error_ret:
	244	return ret;
	245	}
1637db44	246
d96d1337 JC	247	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	248	{
	249	struct iio_poll_func *pf = p;
	250	pf->timestamp = iio_get_time_ns();
	251	return IRQ_WAKE_THREAD;
	252	}
	253	EXPORT_SYMBOL(iio_pollfunc_store_time);
	254
21b185f8 JC	255	struct iio_poll_func
	256	iio_alloc_pollfunc(irqreturn_t (h)(int irq, void *p),
	257	irqreturn_t (thread)(int irq, void p),
	258	int type,
e65bc6ac	259	struct iio_dev *indio_dev,
21b185f8 JC	260	const char *fmt,
	261	...)
	262	{
	263	va_list vargs;
	264	struct iio_poll_func *pf;
	265
	266	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	267	if (pf == NULL)
	268	return NULL;
	269	va_start(vargs, fmt);
	270	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	271	va_end(vargs);
	272	if (pf->name == NULL) {
	273	kfree(pf);
	274	return NULL;
	275	}
	276	pf->h = h;
	277	pf->thread = thread;
	278	pf->type = type;
e65bc6ac	279	pf->indio_dev = indio_dev;
21b185f8 JC	280
	281	return pf;
	282	}
	283	EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
	284
	285	void iio_dealloc_pollfunc(struct iio_poll_func *pf)
	286	{
	287	kfree(pf->name);
	288	kfree(pf);
	289	}
	290	EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
	291
1637db44	292	/**
860c9c54	293	* iio_trigger_read_current() - trigger consumer sysfs query current trigger
1637db44 JC	294	*
	295	* For trigger consumers the current_trigger interface allows the trigger
	296	* used by the device to be queried.
	297	**/
	298	static ssize_t iio_trigger_read_current(struct device *dev,
	299	struct device_attribute *attr,
	300	char *buf)
	301	{
e53f5ac5	302	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
cb6c89a0	303
f8c6f4e9 JC	304	if (indio_dev->trig)
f8c6f4e9 JC	305	return sprintf(buf, "%s\n", indio_dev->trig->name);
cb6c89a0	306	return 0;
1637db44 JC	307	}
	308
	309	/**
860c9c54	310	* iio_trigger_write_current() - trigger consumer sysfs set current trigger
1637db44 JC	311	*
1637db44 JC	312	* For trigger consumers the current_trigger interface allows the trigger
17666ef3	313	* used for this device to be specified at run time based on the trigger's
1637db44 JC	314	* name.
	315	**/
	316	static ssize_t iio_trigger_write_current(struct device *dev,
	317	struct device_attribute *attr,
	318	const char *buf,
	319	size_t len)
	320	{
e53f5ac5	321	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
f8c6f4e9	322	struct iio_trigger *oldtrig = indio_dev->trig;
43a4360e MH	323	struct iio_trigger *trig;
	324	int ret;
	325
f8c6f4e9 JC	326	mutex_lock(&indio_dev->mlock);
	327	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
	328	mutex_unlock(&indio_dev->mlock);
1637db44 JC	329	return -EBUSY;
1637db44 JC	330	}
f8c6f4e9	331	mutex_unlock(&indio_dev->mlock);
1637db44	332
43a4360e	333	trig = iio_trigger_find_by_name(buf, len);
5dd72ecb JC	334	if (oldtrig == trig)
5dd72ecb JC	335	return len;
43a4360e	336
f8c6f4e9 JC	337	if (trig && indio_dev->info->validate_trigger) {
f8c6f4e9 JC	338	ret = indio_dev->info->validate_trigger(indio_dev, trig);
43a4360e MH	339	if (ret)
	340	return ret;
	341	}
	342
d29f73db	343	if (trig && trig->ops && trig->ops->validate_device) {
f8c6f4e9	344	ret = trig->ops->validate_device(trig, indio_dev);
43a4360e MH	345	if (ret)
	346	return ret;
	347	}
	348
f8c6f4e9	349	indio_dev->trig = trig;
43a4360e	350
a35e1fd2	351	if (oldtrig)
7cbb7537	352	iio_trigger_put(oldtrig);
f8c6f4e9	353	if (indio_dev->trig)
7cbb7537	354	iio_trigger_get(indio_dev->trig);
1637db44 JC	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	393	kfree(trig);
1637db44 JC	394	}
	395
	396	static struct device_type iio_trig_type = {
	397	.release = iio_trig_release,
f59c2576	398	.groups = iio_trig_dev_groups,
1637db44 JC	399	};
1637db44 JC	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
d536321d	419	static struct iio_trigger viio_trigger_alloc(const char fmt, va_list vargs)
1637db44 JC	420	{
	421	struct iio_trigger *trig;
	422	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	423	if (trig) {
d96d1337	424	int i;
1637db44	425	trig->dev.type = &iio_trig_type;
5aaaeba8	426	trig->dev.bus = &iio_bus_type;
1637db44	427	device_initialize(&trig->dev);
d96d1337	428
59c85e82 JC	429	mutex_init(&trig->pool_lock);
	430	trig->subirq_base
	431	= irq_alloc_descs(-1, 0,
	432	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	433	0);
	434	if (trig->subirq_base < 0) {
	435	kfree(trig);
	436	return NULL;
	437	}
d536321d	438
59c85e82	439	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
59c85e82 JC	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	459	}
d536321d JA	460
	461	return trig;
	462	}
	463
	464	struct iio_trigger iio_trigger_alloc(const char fmt, ...)
	465	{
	466	struct iio_trigger *trig;
	467	va_list vargs;
	468
	469	va_start(vargs, fmt);
	470	trig = viio_trigger_alloc(fmt, vargs);
	471	va_end(vargs);
	472
1637db44 JC	473	return trig;
1637db44 JC	474	}
7cbb7537	475	EXPORT_SYMBOL(iio_trigger_alloc);
1637db44	476
7cbb7537	477	void iio_trigger_free(struct iio_trigger *trig)
1637db44 JC	478	{
	479	if (trig)
	480	put_device(&trig->dev);
	481	}
7cbb7537	482	EXPORT_SYMBOL(iio_trigger_free);
1637db44	483
d536321d JA	484	static void devm_iio_trigger_release(struct device dev, void res)
	485	{
	486	iio_trigger_free((struct iio_trigger *)res);
	487	}
	488
	489	static int devm_iio_trigger_match(struct device dev, void res, void *data)
	490	{
	491	struct iio_trigger **r = res;
	492
	493	if (!r \|\| !*r) {
	494	WARN_ON(!r \|\| !*r);
	495	return 0;
	496	}
	497
	498	return *r == data;
	499	}
	500
a7e57dce SK	501	/**
	502	* devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
	503	* @dev: Device to allocate iio_trigger for
	504	* @fmt: trigger name format. If it includes format
	505	* specifiers, the additional arguments following
	506	* format are formatted and inserted in the resulting
	507	* string replacing their respective specifiers.
	508	*
	509	* Managed iio_trigger_alloc. iio_trigger allocated with this function is
	510	* automatically freed on driver detach.
	511	*
	512	* If an iio_trigger allocated with this function needs to be freed separately,
	513	* devm_iio_trigger_free() must be used.
	514	*
	515	* RETURNS:
	516	* Pointer to allocated iio_trigger on success, NULL on failure.
	517	*/
d536321d JA	518	struct iio_trigger devm_iio_trigger_alloc(struct device dev,
	519	const char *fmt, ...)
	520	{
	521	struct iio_trigger *ptr, trig;
	522	va_list vargs;
	523
	524	ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
	525	GFP_KERNEL);
	526	if (!ptr)
	527	return NULL;
	528
	529	/* use raw alloc_dr for kmalloc caller tracing */
	530	va_start(vargs, fmt);
	531	trig = viio_trigger_alloc(fmt, vargs);
	532	va_end(vargs);
	533	if (trig) {
	534	*ptr = trig;
	535	devres_add(dev, ptr);
	536	} else {
	537	devres_free(ptr);
	538	}
	539
	540	return trig;
	541	}
	542	EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
	543
a7e57dce SK	544	/**
	545	* devm_iio_trigger_free - Resource-managed iio_trigger_free()
	546	* @dev: Device this iio_dev belongs to
	547	* @iio_trig: the iio_trigger associated with the device
	548	*
	549	* Free iio_trigger allocated with devm_iio_trigger_alloc().
	550	*/
d536321d JA	551	void devm_iio_trigger_free(struct device dev, struct iio_trigger iio_trig)
	552	{
	553	int rc;
	554
	555	rc = devres_release(dev, devm_iio_trigger_release,
	556	devm_iio_trigger_match, iio_trig);
	557	WARN_ON(rc);
	558	}
	559	EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
	560
67be8e32	561	void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
1637db44	562	{
f8c6f4e9	563	indio_dev->groups[indio_dev->groupcounter++] =
26d25ae3	564	&iio_trigger_consumer_attr_group;
1637db44	565	}
1637db44	566
f8c6f4e9	567	void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
1637db44	568	{
860c9c54	569	/* Clean up an associated but not attached trigger reference */
f8c6f4e9	570	if (indio_dev->trig)
7cbb7537	571	iio_trigger_put(indio_dev->trig);
1637db44	572	}
1637db44	573
3b99fb76	574	int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
c3db00cc	575	{
67be8e32 JC	576	return iio_trigger_attach_poll_func(indio_dev->trig,
67be8e32 JC	577	indio_dev->pollfunc);
c3db00cc	578	}
3b99fb76	579	EXPORT_SYMBOL(iio_triggered_buffer_postenable);
c3db00cc	580
3b99fb76	581	int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
c3db00cc	582	{
034bd7b5	583	return iio_trigger_detach_poll_func(indio_dev->trig,
67be8e32	584	indio_dev->pollfunc);
c3db00cc	585	}
3b99fb76	586	EXPORT_SYMBOL(iio_triggered_buffer_predisable);