[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,
};

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 (!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 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;
}

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;
}

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);

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	};
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;
a1a8e1dc LPC	130
	131	if (!atomic_read(&trig->use_count)) {
	132	atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	133
	134	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	135	if (trig->subirqs[i].enabled)
d96d1337	136	generic_handle_irq(trig->subirq_base + i);
a1a8e1dc LPC	137	else
	138	iio_trigger_notify_done(trig);
	139	}
	140	}
1637db44 JC	141	}
1637db44 JC	142	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	143
	144	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	145	{
	146	iio_trigger_poll(private, iio_get_time_ns());
	147	return IRQ_HANDLED;
	148	}
	149	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	150
1f785681 JC	151	void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
	152	{
	153	int i;
a1a8e1dc LPC	154
	155	if (!atomic_read(&trig->use_count)) {
	156	atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	157
	158	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	159	if (trig->subirqs[i].enabled)
1f785681	160	handle_nested_irq(trig->subirq_base + i);
a1a8e1dc LPC	161	else
	162	iio_trigger_notify_done(trig);
	163	}
	164	}
1f785681 JC	165	}
	166	EXPORT_SYMBOL(iio_trigger_poll_chained);
	167
1637db44 JC	168	void iio_trigger_notify_done(struct iio_trigger *trig)
1637db44 JC	169	{
a1a8e1dc LPC	170	if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
a1a8e1dc LPC	171	trig->ops->try_reenable)
e69616b1	172	if (trig->ops->try_reenable(trig))
860c9c54	173	/* Missed an interrupt so launch new poll now */
7b2c33b1	174	iio_trigger_poll(trig, 0);
1637db44 JC	175	}
	176	EXPORT_SYMBOL(iio_trigger_notify_done);
	177
1637db44	178	/* Trigger Consumer related functions */
208b813c JC	179	static int iio_trigger_get_irq(struct iio_trigger *trig)
	180	{
	181	int ret;
	182	mutex_lock(&trig->pool_lock);
	183	ret = bitmap_find_free_region(trig->pool,
	184	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	185	ilog2(1));
	186	mutex_unlock(&trig->pool_lock);
	187	if (ret >= 0)
	188	ret += trig->subirq_base;
	189
	190	return ret;
	191	}
	192
	193	static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
	194	{
	195	mutex_lock(&trig->pool_lock);
	196	clear_bit(irq - trig->subirq_base, trig->pool);
	197	mutex_unlock(&trig->pool_lock);
	198	}
1637db44 JC	199
	200	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	201	* may be needed if the pollfuncs do not include the data read for the
	202	* triggering device.
	203	* This is not currently handled. Alternative of not enabling trigger unless
	204	* the relevant function is in there may be the best option.
	205	*/
860c9c54	206	/* Worth protecting against double additions? */
208b813c JC	207	static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
208b813c JC	208	struct iio_poll_func *pf)
1637db44 JC	209	{
1637db44 JC	210	int ret = 0;
51c060a0 JC	211	bool notinuse
	212	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	213
860c9c54	214	/* Prevent the module from being removed whilst attached to a trigger */
f60c4a02	215	__module_get(pf->indio_dev->info->driver_module);
51c060a0 JC	216	pf->irq = iio_trigger_get_irq(trig);
	217	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	218	pf->type, pf->name,
	219	pf);
5dd72ecb JC	220	if (ret < 0) {
	221	module_put(pf->indio_dev->info->driver_module);
	222	return ret;
	223	}
	224
	225	if (trig->ops && trig->ops->set_trigger_state && notinuse) {
d29f73db	226	ret = trig->ops->set_trigger_state(trig, true);
5dd72ecb JC	227	if (ret < 0)
	228	module_put(pf->indio_dev->info->driver_module);
	229	}
d96d1337	230
1637db44 JC	231	return ret;
1637db44 JC	232	}
1637db44	233
034bd7b5	234	static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
208b813c	235	struct iio_poll_func *pf)
1637db44	236	{
51c060a0 JC	237	int ret = 0;
	238	bool no_other_users
	239	= (bitmap_weight(trig->pool,
	240	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	241	== 1);
d29f73db JC	242	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
d29f73db JC	243	ret = trig->ops->set_trigger_state(trig, false);
51c060a0 JC	244	if (ret)
51c060a0 JC	245	goto error_ret;
1637db44	246	}
51c060a0 JC	247	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	248	free_irq(pf->irq, pf);
f60c4a02	249	module_put(pf->indio_dev->info->driver_module);
1637db44 JC	250
	251	error_ret:
	252	return ret;
	253	}
1637db44	254
d96d1337 JC	255	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	256	{
	257	struct iio_poll_func *pf = p;
	258	pf->timestamp = iio_get_time_ns();
	259	return IRQ_WAKE_THREAD;
	260	}
	261	EXPORT_SYMBOL(iio_pollfunc_store_time);
	262
21b185f8 JC	263	struct iio_poll_func
	264	iio_alloc_pollfunc(irqreturn_t (h)(int irq, void *p),
	265	irqreturn_t (thread)(int irq, void p),
	266	int type,
e65bc6ac	267	struct iio_dev *indio_dev,
21b185f8 JC	268	const char *fmt,
	269	...)
	270	{
	271	va_list vargs;
	272	struct iio_poll_func *pf;
	273
	274	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	275	if (pf == NULL)
	276	return NULL;
	277	va_start(vargs, fmt);
	278	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	279	va_end(vargs);
	280	if (pf->name == NULL) {
	281	kfree(pf);
	282	return NULL;
	283	}
	284	pf->h = h;
	285	pf->thread = thread;
	286	pf->type = type;
e65bc6ac	287	pf->indio_dev = indio_dev;
21b185f8 JC	288
	289	return pf;
	290	}
	291	EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
	292
	293	void iio_dealloc_pollfunc(struct iio_poll_func *pf)
	294	{
	295	kfree(pf->name);
	296	kfree(pf);
	297	}
	298	EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
	299
1637db44	300	/**
860c9c54	301	* iio_trigger_read_current() - trigger consumer sysfs query current trigger
1637db44 JC	302	*
	303	* For trigger consumers the current_trigger interface allows the trigger
	304	* used by the device to be queried.
	305	**/
	306	static ssize_t iio_trigger_read_current(struct device *dev,
	307	struct device_attribute *attr,
	308	char *buf)
	309	{
e53f5ac5	310	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
cb6c89a0	311
f8c6f4e9 JC	312	if (indio_dev->trig)
f8c6f4e9 JC	313	return sprintf(buf, "%s\n", indio_dev->trig->name);
cb6c89a0	314	return 0;
1637db44 JC	315	}
	316
	317	/**
860c9c54	318	* iio_trigger_write_current() - trigger consumer sysfs set current trigger
1637db44 JC	319	*
	320	* For trigger consumers the current_trigger interface allows the trigger
	321	* used for this device to be specified at run time based on the triggers
	322	* name.
	323	**/
	324	static ssize_t iio_trigger_write_current(struct device *dev,
	325	struct device_attribute *attr,
	326	const char *buf,
	327	size_t len)
	328	{
e53f5ac5	329	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
f8c6f4e9	330	struct iio_trigger *oldtrig = indio_dev->trig;
43a4360e MH	331	struct iio_trigger *trig;
	332	int ret;
	333
f8c6f4e9 JC	334	mutex_lock(&indio_dev->mlock);
	335	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
	336	mutex_unlock(&indio_dev->mlock);
1637db44 JC	337	return -EBUSY;
1637db44 JC	338	}
f8c6f4e9	339	mutex_unlock(&indio_dev->mlock);
1637db44	340
43a4360e	341	trig = iio_trigger_find_by_name(buf, len);
5dd72ecb JC	342	if (oldtrig == trig)
5dd72ecb JC	343	return len;
43a4360e	344
f8c6f4e9 JC	345	if (trig && indio_dev->info->validate_trigger) {
f8c6f4e9 JC	346	ret = indio_dev->info->validate_trigger(indio_dev, trig);
43a4360e MH	347	if (ret)
	348	return ret;
	349	}
	350
d29f73db	351	if (trig && trig->ops && trig->ops->validate_device) {
f8c6f4e9	352	ret = trig->ops->validate_device(trig, indio_dev);
43a4360e MH	353	if (ret)
	354	return ret;
	355	}
	356
f8c6f4e9	357	indio_dev->trig = trig;
43a4360e	358
f8c6f4e9	359	if (oldtrig && indio_dev->trig != oldtrig)
7cbb7537	360	iio_trigger_put(oldtrig);
f8c6f4e9	361	if (indio_dev->trig)
7cbb7537	362	iio_trigger_get(indio_dev->trig);
1637db44 JC	363
	364	return len;
	365	}
	366
74112d3f GKH	367	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	368	iio_trigger_read_current,
	369	iio_trigger_write_current);
1637db44 JC	370
	371	static struct attribute *iio_trigger_consumer_attrs[] = {
	372	&dev_attr_current_trigger.attr,
	373	NULL,
	374	};
	375
	376	static const struct attribute_group iio_trigger_consumer_attr_group = {
	377	.name = "trigger",
	378	.attrs = iio_trigger_consumer_attrs,
	379	};
	380
	381	static void iio_trig_release(struct device *device)
	382	{
	383	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	384	int i;
	385
	386	if (trig->subirq_base) {
	387	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	388	irq_modify_status(trig->subirq_base + i,
	389	IRQ_NOAUTOEN,
	390	IRQ_NOREQUEST \| IRQ_NOPROBE);
	391	irq_set_chip(trig->subirq_base + i,
	392	NULL);
	393	irq_set_handler(trig->subirq_base + i,
	394	NULL);
	395	}
	396
	397	irq_free_descs(trig->subirq_base,
	398	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	399	}
59c85e82	400	kfree(trig->name);
1637db44	401	kfree(trig);
1637db44 JC	402	}
	403
	404	static struct device_type iio_trig_type = {
	405	.release = iio_trig_release,
6d459aa0	406	.groups = iio_trig_attr_groups,
1637db44 JC	407	};
1637db44 JC	408
d96d1337 JC	409	static void iio_trig_subirqmask(struct irq_data *d)
	410	{
	411	struct irq_chip *chip = irq_data_get_irq_chip(d);
	412	struct iio_trigger *trig
	413	= container_of(chip,
	414	struct iio_trigger, subirq_chip);
	415	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	416	}
	417
	418	static void iio_trig_subirqunmask(struct irq_data *d)
	419	{
	420	struct irq_chip *chip = irq_data_get_irq_chip(d);
	421	struct iio_trigger *trig
	422	= container_of(chip,
	423	struct iio_trigger, subirq_chip);
	424	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	425	}
	426
d536321d	427	static struct iio_trigger viio_trigger_alloc(const char fmt, va_list vargs)
1637db44 JC	428	{
	429	struct iio_trigger *trig;
	430	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	431	if (trig) {
d96d1337	432	int i;
1637db44	433	trig->dev.type = &iio_trig_type;
5aaaeba8	434	trig->dev.bus = &iio_bus_type;
1637db44	435	device_initialize(&trig->dev);
d96d1337	436
59c85e82 JC	437	mutex_init(&trig->pool_lock);
	438	trig->subirq_base
	439	= irq_alloc_descs(-1, 0,
	440	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	441	0);
	442	if (trig->subirq_base < 0) {
	443	kfree(trig);
	444	return NULL;
	445	}
d536321d	446
59c85e82	447	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
59c85e82 JC	448	if (trig->name == NULL) {
	449	irq_free_descs(trig->subirq_base,
	450	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	451	kfree(trig);
	452	return NULL;
	453	}
	454	trig->subirq_chip.name = trig->name;
	455	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	456	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	457	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	458	irq_set_chip(trig->subirq_base + i,
	459	&trig->subirq_chip);
	460	irq_set_handler(trig->subirq_base + i,
	461	&handle_simple_irq);
	462	irq_modify_status(trig->subirq_base + i,
	463	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	464	IRQ_NOPROBE);
d96d1337	465	}
5f9c035c	466	get_device(&trig->dev);
1637db44	467	}
d536321d JA	468
	469	return trig;
	470	}
	471
	472	struct iio_trigger iio_trigger_alloc(const char fmt, ...)
	473	{
	474	struct iio_trigger *trig;
	475	va_list vargs;
	476
	477	va_start(vargs, fmt);
	478	trig = viio_trigger_alloc(fmt, vargs);
	479	va_end(vargs);
	480
1637db44 JC	481	return trig;
1637db44 JC	482	}
7cbb7537	483	EXPORT_SYMBOL(iio_trigger_alloc);
1637db44	484
7cbb7537	485	void iio_trigger_free(struct iio_trigger *trig)
1637db44 JC	486	{
	487	if (trig)
	488	put_device(&trig->dev);
	489	}
7cbb7537	490	EXPORT_SYMBOL(iio_trigger_free);
1637db44	491
d536321d JA	492	static void devm_iio_trigger_release(struct device dev, void res)
	493	{
	494	iio_trigger_free((struct iio_trigger *)res);
	495	}
	496
	497	static int devm_iio_trigger_match(struct device dev, void res, void *data)
	498	{
	499	struct iio_trigger **r = res;
	500
	501	if (!r \|\| !*r) {
	502	WARN_ON(!r \|\| !*r);
	503	return 0;
	504	}
	505
	506	return *r == data;
	507	}
	508
	509	struct iio_trigger devm_iio_trigger_alloc(struct device dev,
	510	const char *fmt, ...)
	511	{
	512	struct iio_trigger *ptr, trig;
	513	va_list vargs;
	514
	515	ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
	516	GFP_KERNEL);
	517	if (!ptr)
	518	return NULL;
	519
	520	/* use raw alloc_dr for kmalloc caller tracing */
	521	va_start(vargs, fmt);
	522	trig = viio_trigger_alloc(fmt, vargs);
	523	va_end(vargs);
	524	if (trig) {
	525	*ptr = trig;
	526	devres_add(dev, ptr);
	527	} else {
	528	devres_free(ptr);
	529	}
	530
	531	return trig;
	532	}
	533	EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
	534
	535	void devm_iio_trigger_free(struct device dev, struct iio_trigger iio_trig)
	536	{
	537	int rc;
	538
	539	rc = devres_release(dev, devm_iio_trigger_release,
	540	devm_iio_trigger_match, iio_trig);
	541	WARN_ON(rc);
	542	}
	543	EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
	544
67be8e32	545	void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
1637db44	546	{
f8c6f4e9	547	indio_dev->groups[indio_dev->groupcounter++] =
26d25ae3	548	&iio_trigger_consumer_attr_group;
1637db44	549	}
1637db44	550
f8c6f4e9	551	void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
1637db44	552	{
860c9c54	553	/* Clean up an associated but not attached trigger reference */
f8c6f4e9	554	if (indio_dev->trig)
7cbb7537	555	iio_trigger_put(indio_dev->trig);
1637db44	556	}
1637db44	557
3b99fb76	558	int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
c3db00cc	559	{
67be8e32 JC	560	return iio_trigger_attach_poll_func(indio_dev->trig,
67be8e32 JC	561	indio_dev->pollfunc);
c3db00cc	562	}
3b99fb76	563	EXPORT_SYMBOL(iio_triggered_buffer_postenable);
c3db00cc	564
3b99fb76	565	int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
c3db00cc	566	{
034bd7b5	567	return iio_trigger_detach_poll_func(indio_dev->trig,
67be8e32	568	indio_dev->pollfunc);
c3db00cc	569	}
3b99fb76	570	EXPORT_SYMBOL(iio_triggered_buffer_predisable);