[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);

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)
		return trig_info->id;

	/* 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);
	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)
{
	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);
	return IRQ_HANDLED;
}
EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);

void iio_trigger_poll_chained(struct iio_trigger *trig)
{
	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);
}
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)
			return ret;
	}
	iio_trigger_put_irq(trig, pf->irq);
	free_irq(pf->irq, pf);
	module_put(pf->indio_dev->info->driver_module);

	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	64	trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
92825ff9 HK	65	if (trig_info->id < 0)
	66	return trig_info->id;
	67
1637db44 JC	68	/* Set the name used for the sysfs directory etc */
	69	dev_set_name(&trig_info->dev, "trigger%ld",
	70	(unsigned long) trig_info->id);
	71
	72	ret = device_add(&trig_info->dev);
	73	if (ret)
	74	goto error_unregister_id;
	75
1637db44 JC	76	/* Add to list of available triggers held by the IIO core */
	77	mutex_lock(&iio_trigger_list_lock);
	78	list_add_tail(&trig_info->list, &iio_trigger_list);
	79	mutex_unlock(&iio_trigger_list_lock);
	80
	81	return 0;
	82
1637db44	83	error_unregister_id:
47c24fdd	84	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44 JC	85	return ret;
	86	}
	87	EXPORT_SYMBOL(iio_trigger_register);
	88
	89	void iio_trigger_unregister(struct iio_trigger *trig_info)
	90	{
1637db44	91	mutex_lock(&iio_trigger_list_lock);
582e5489	92	list_del(&trig_info->list);
1637db44 JC	93	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	94
47c24fdd	95	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44	96	/* Possible issue in here */
8bade406	97	device_del(&trig_info->dev);
1637db44 JC	98	}
	99	EXPORT_SYMBOL(iio_trigger_unregister);
	100
f6517f22 JC	101	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	102	size_t len)
1637db44	103	{
f6517f22	104	struct iio_trigger trig = NULL, iter;
7c327857	105
1637db44	106	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	107	list_for_each_entry(iter, &iio_trigger_list, list)
	108	if (sysfs_streq(iter->name, name)) {
	109	trig = iter;
1637db44 JC	110	break;
1637db44 JC	111	}
1637db44 JC	112	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	113
f6517f22	114	return trig;
5f87404d	115	}
1637db44	116
398fd22b	117	void iio_trigger_poll(struct iio_trigger *trig)
1637db44	118	{
d96d1337	119	int i;
a1a8e1dc LPC	120
	121	if (!atomic_read(&trig->use_count)) {
	122	atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	123
	124	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	125	if (trig->subirqs[i].enabled)
d96d1337	126	generic_handle_irq(trig->subirq_base + i);
a1a8e1dc LPC	127	else
	128	iio_trigger_notify_done(trig);
	129	}
	130	}
1637db44 JC	131	}
1637db44 JC	132	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	133
	134	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	135	{
398fd22b	136	iio_trigger_poll(private);
8384d957 JC	137	return IRQ_HANDLED;
	138	}
	139	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	140
398fd22b	141	void iio_trigger_poll_chained(struct iio_trigger *trig)
1f785681 JC	142	{
1f785681 JC	143	int i;
a1a8e1dc LPC	144
	145	if (!atomic_read(&trig->use_count)) {
	146	atomic_set(&trig->use_count, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	147
	148	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	149	if (trig->subirqs[i].enabled)
1f785681	150	handle_nested_irq(trig->subirq_base + i);
a1a8e1dc LPC	151	else
	152	iio_trigger_notify_done(trig);
	153	}
	154	}
1f785681 JC	155	}
	156	EXPORT_SYMBOL(iio_trigger_poll_chained);
	157
1637db44 JC	158	void iio_trigger_notify_done(struct iio_trigger *trig)
1637db44 JC	159	{
a1a8e1dc LPC	160	if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
a1a8e1dc LPC	161	trig->ops->try_reenable)
e69616b1	162	if (trig->ops->try_reenable(trig))
860c9c54	163	/* Missed an interrupt so launch new poll now */
398fd22b	164	iio_trigger_poll(trig);
1637db44 JC	165	}
	166	EXPORT_SYMBOL(iio_trigger_notify_done);
	167
1637db44	168	/* Trigger Consumer related functions */
208b813c JC	169	static int iio_trigger_get_irq(struct iio_trigger *trig)
	170	{
	171	int ret;
	172	mutex_lock(&trig->pool_lock);
	173	ret = bitmap_find_free_region(trig->pool,
	174	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	175	ilog2(1));
	176	mutex_unlock(&trig->pool_lock);
	177	if (ret >= 0)
	178	ret += trig->subirq_base;
	179
	180	return ret;
	181	}
	182
	183	static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
	184	{
	185	mutex_lock(&trig->pool_lock);
	186	clear_bit(irq - trig->subirq_base, trig->pool);
	187	mutex_unlock(&trig->pool_lock);
	188	}
1637db44 JC	189
	190	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	191	* may be needed if the pollfuncs do not include the data read for the
	192	* triggering device.
	193	* This is not currently handled. Alternative of not enabling trigger unless
	194	* the relevant function is in there may be the best option.
	195	*/
860c9c54	196	/* Worth protecting against double additions? */
208b813c JC	197	static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
208b813c JC	198	struct iio_poll_func *pf)
1637db44 JC	199	{
1637db44 JC	200	int ret = 0;
51c060a0 JC	201	bool notinuse
	202	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	203
860c9c54	204	/* Prevent the module from being removed whilst attached to a trigger */
f60c4a02	205	__module_get(pf->indio_dev->info->driver_module);
51c060a0 JC	206	pf->irq = iio_trigger_get_irq(trig);
	207	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	208	pf->type, pf->name,
	209	pf);
5dd72ecb JC	210	if (ret < 0) {
	211	module_put(pf->indio_dev->info->driver_module);
	212	return ret;
	213	}
	214
	215	if (trig->ops && trig->ops->set_trigger_state && notinuse) {
d29f73db	216	ret = trig->ops->set_trigger_state(trig, true);
5dd72ecb JC	217	if (ret < 0)
	218	module_put(pf->indio_dev->info->driver_module);
	219	}
d96d1337	220
1637db44 JC	221	return ret;
1637db44 JC	222	}
1637db44	223
034bd7b5	224	static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
208b813c	225	struct iio_poll_func *pf)
1637db44	226	{
51c060a0 JC	227	int ret = 0;
	228	bool no_other_users
	229	= (bitmap_weight(trig->pool,
	230	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	231	== 1);
d29f73db JC	232	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
d29f73db JC	233	ret = trig->ops->set_trigger_state(trig, false);
51c060a0	234	if (ret)
92825ff9	235	return ret;
1637db44	236	}
51c060a0 JC	237	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	238	free_irq(pf->irq, pf);
f60c4a02	239	module_put(pf->indio_dev->info->driver_module);
1637db44	240
1637db44 JC	241	return ret;
1637db44 JC	242	}
1637db44	243
d96d1337 JC	244	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	245	{
	246	struct iio_poll_func *pf = p;
	247	pf->timestamp = iio_get_time_ns();
	248	return IRQ_WAKE_THREAD;
	249	}
	250	EXPORT_SYMBOL(iio_pollfunc_store_time);
	251
21b185f8 JC	252	struct iio_poll_func
	253	iio_alloc_pollfunc(irqreturn_t (h)(int irq, void *p),
	254	irqreturn_t (thread)(int irq, void p),
	255	int type,
e65bc6ac	256	struct iio_dev *indio_dev,
21b185f8 JC	257	const char *fmt,
	258	...)
	259	{
	260	va_list vargs;
	261	struct iio_poll_func *pf;
	262
	263	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	264	if (pf == NULL)
	265	return NULL;
	266	va_start(vargs, fmt);
	267	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	268	va_end(vargs);
	269	if (pf->name == NULL) {
	270	kfree(pf);
	271	return NULL;
	272	}
	273	pf->h = h;
	274	pf->thread = thread;
	275	pf->type = type;
e65bc6ac	276	pf->indio_dev = indio_dev;
21b185f8 JC	277
	278	return pf;
	279	}
	280	EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
	281
	282	void iio_dealloc_pollfunc(struct iio_poll_func *pf)
	283	{
	284	kfree(pf->name);
	285	kfree(pf);
	286	}
	287	EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
	288
1637db44	289	/**
860c9c54	290	* iio_trigger_read_current() - trigger consumer sysfs query current trigger
1637db44 JC	291	*
	292	* For trigger consumers the current_trigger interface allows the trigger
	293	* used by the device to be queried.
	294	**/
	295	static ssize_t iio_trigger_read_current(struct device *dev,
	296	struct device_attribute *attr,
	297	char *buf)
	298	{
e53f5ac5	299	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
cb6c89a0	300
f8c6f4e9 JC	301	if (indio_dev->trig)
f8c6f4e9 JC	302	return sprintf(buf, "%s\n", indio_dev->trig->name);
cb6c89a0	303	return 0;
1637db44 JC	304	}
	305
	306	/**
860c9c54	307	* iio_trigger_write_current() - trigger consumer sysfs set current trigger
1637db44 JC	308	*
1637db44 JC	309	* For trigger consumers the current_trigger interface allows the trigger
17666ef3	310	* used for this device to be specified at run time based on the trigger's
1637db44 JC	311	* name.
	312	**/
	313	static ssize_t iio_trigger_write_current(struct device *dev,
	314	struct device_attribute *attr,
	315	const char *buf,
	316	size_t len)
	317	{
e53f5ac5	318	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
f8c6f4e9	319	struct iio_trigger *oldtrig = indio_dev->trig;
43a4360e MH	320	struct iio_trigger *trig;
	321	int ret;
	322
f8c6f4e9 JC	323	mutex_lock(&indio_dev->mlock);
	324	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
	325	mutex_unlock(&indio_dev->mlock);
1637db44 JC	326	return -EBUSY;
1637db44 JC	327	}
f8c6f4e9	328	mutex_unlock(&indio_dev->mlock);
1637db44	329
43a4360e	330	trig = iio_trigger_find_by_name(buf, len);
5dd72ecb JC	331	if (oldtrig == trig)
5dd72ecb JC	332	return len;
43a4360e	333
f8c6f4e9 JC	334	if (trig && indio_dev->info->validate_trigger) {
f8c6f4e9 JC	335	ret = indio_dev->info->validate_trigger(indio_dev, trig);
43a4360e MH	336	if (ret)
	337	return ret;
	338	}
	339
d29f73db	340	if (trig && trig->ops && trig->ops->validate_device) {
f8c6f4e9	341	ret = trig->ops->validate_device(trig, indio_dev);
43a4360e MH	342	if (ret)
	343	return ret;
	344	}
	345
f8c6f4e9	346	indio_dev->trig = trig;
43a4360e	347
a35e1fd2	348	if (oldtrig)
7cbb7537	349	iio_trigger_put(oldtrig);
f8c6f4e9	350	if (indio_dev->trig)
7cbb7537	351	iio_trigger_get(indio_dev->trig);
1637db44 JC	352
	353	return len;
	354	}
	355
74112d3f GKH	356	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	357	iio_trigger_read_current,
	358	iio_trigger_write_current);
1637db44 JC	359
	360	static struct attribute *iio_trigger_consumer_attrs[] = {
	361	&dev_attr_current_trigger.attr,
	362	NULL,
	363	};
	364
	365	static const struct attribute_group iio_trigger_consumer_attr_group = {
	366	.name = "trigger",
	367	.attrs = iio_trigger_consumer_attrs,
	368	};
	369
	370	static void iio_trig_release(struct device *device)
	371	{
	372	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	373	int i;
	374
	375	if (trig->subirq_base) {
	376	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	377	irq_modify_status(trig->subirq_base + i,
	378	IRQ_NOAUTOEN,
	379	IRQ_NOREQUEST \| IRQ_NOPROBE);
	380	irq_set_chip(trig->subirq_base + i,
	381	NULL);
	382	irq_set_handler(trig->subirq_base + i,
	383	NULL);
	384	}
	385
	386	irq_free_descs(trig->subirq_base,
	387	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	388	}
59c85e82	389	kfree(trig->name);
1637db44	390	kfree(trig);
1637db44 JC	391	}
	392
	393	static struct device_type iio_trig_type = {
	394	.release = iio_trig_release,
f59c2576	395	.groups = iio_trig_dev_groups,
1637db44 JC	396	};
1637db44 JC	397
d96d1337 JC	398	static void iio_trig_subirqmask(struct irq_data *d)
	399	{
	400	struct irq_chip *chip = irq_data_get_irq_chip(d);
	401	struct iio_trigger *trig
	402	= container_of(chip,
	403	struct iio_trigger, subirq_chip);
	404	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	405	}
	406
	407	static void iio_trig_subirqunmask(struct irq_data *d)
	408	{
	409	struct irq_chip *chip = irq_data_get_irq_chip(d);
	410	struct iio_trigger *trig
	411	= container_of(chip,
	412	struct iio_trigger, subirq_chip);
	413	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	414	}
	415
d536321d	416	static struct iio_trigger viio_trigger_alloc(const char fmt, va_list vargs)
1637db44 JC	417	{
	418	struct iio_trigger *trig;
	419	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	420	if (trig) {
d96d1337	421	int i;
1637db44	422	trig->dev.type = &iio_trig_type;
5aaaeba8	423	trig->dev.bus = &iio_bus_type;
1637db44	424	device_initialize(&trig->dev);
d96d1337	425
59c85e82 JC	426	mutex_init(&trig->pool_lock);
	427	trig->subirq_base
	428	= irq_alloc_descs(-1, 0,
	429	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	430	0);
	431	if (trig->subirq_base < 0) {
	432	kfree(trig);
	433	return NULL;
	434	}
d536321d	435
59c85e82	436	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
59c85e82 JC	437	if (trig->name == NULL) {
	438	irq_free_descs(trig->subirq_base,
	439	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	440	kfree(trig);
	441	return NULL;
	442	}
	443	trig->subirq_chip.name = trig->name;
	444	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	445	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	446	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	447	irq_set_chip(trig->subirq_base + i,
	448	&trig->subirq_chip);
	449	irq_set_handler(trig->subirq_base + i,
	450	&handle_simple_irq);
	451	irq_modify_status(trig->subirq_base + i,
	452	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	453	IRQ_NOPROBE);
d96d1337	454	}
5f9c035c	455	get_device(&trig->dev);
1637db44	456	}
d536321d JA	457
	458	return trig;
	459	}
	460
	461	struct iio_trigger iio_trigger_alloc(const char fmt, ...)
	462	{
	463	struct iio_trigger *trig;
	464	va_list vargs;
	465
	466	va_start(vargs, fmt);
	467	trig = viio_trigger_alloc(fmt, vargs);
	468	va_end(vargs);
	469
1637db44 JC	470	return trig;
1637db44 JC	471	}
7cbb7537	472	EXPORT_SYMBOL(iio_trigger_alloc);
1637db44	473
7cbb7537	474	void iio_trigger_free(struct iio_trigger *trig)
1637db44 JC	475	{
	476	if (trig)
	477	put_device(&trig->dev);
	478	}
7cbb7537	479	EXPORT_SYMBOL(iio_trigger_free);
1637db44	480
d536321d JA	481	static void devm_iio_trigger_release(struct device dev, void res)
	482	{
	483	iio_trigger_free((struct iio_trigger *)res);
	484	}
	485
	486	static int devm_iio_trigger_match(struct device dev, void res, void *data)
	487	{
	488	struct iio_trigger **r = res;
	489
	490	if (!r \|\| !*r) {
	491	WARN_ON(!r \|\| !*r);
	492	return 0;
	493	}
	494
	495	return *r == data;
	496	}
	497
a7e57dce SK	498	/**
	499	* devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
	500	* @dev: Device to allocate iio_trigger for
	501	* @fmt: trigger name format. If it includes format
	502	* specifiers, the additional arguments following
	503	* format are formatted and inserted in the resulting
	504	* string replacing their respective specifiers.
	505	*
	506	* Managed iio_trigger_alloc. iio_trigger allocated with this function is
	507	* automatically freed on driver detach.
	508	*
	509	* If an iio_trigger allocated with this function needs to be freed separately,
	510	* devm_iio_trigger_free() must be used.
	511	*
	512	* RETURNS:
	513	* Pointer to allocated iio_trigger on success, NULL on failure.
	514	*/
d536321d JA	515	struct iio_trigger devm_iio_trigger_alloc(struct device dev,
	516	const char *fmt, ...)
	517	{
	518	struct iio_trigger *ptr, trig;
	519	va_list vargs;
	520
	521	ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
	522	GFP_KERNEL);
	523	if (!ptr)
	524	return NULL;
	525
	526	/* use raw alloc_dr for kmalloc caller tracing */
	527	va_start(vargs, fmt);
	528	trig = viio_trigger_alloc(fmt, vargs);
	529	va_end(vargs);
	530	if (trig) {
	531	*ptr = trig;
	532	devres_add(dev, ptr);
	533	} else {
	534	devres_free(ptr);
	535	}
	536
	537	return trig;
	538	}
	539	EXPORT_SYMBOL_GPL(devm_iio_trigger_alloc);
	540
a7e57dce SK	541	/**
	542	* devm_iio_trigger_free - Resource-managed iio_trigger_free()
	543	* @dev: Device this iio_dev belongs to
	544	* @iio_trig: the iio_trigger associated with the device
	545	*
	546	* Free iio_trigger allocated with devm_iio_trigger_alloc().
	547	*/
d536321d JA	548	void devm_iio_trigger_free(struct device dev, struct iio_trigger iio_trig)
	549	{
	550	int rc;
	551
	552	rc = devres_release(dev, devm_iio_trigger_release,
	553	devm_iio_trigger_match, iio_trig);
	554	WARN_ON(rc);
	555	}
	556	EXPORT_SYMBOL_GPL(devm_iio_trigger_free);
	557
67be8e32	558	void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
1637db44	559	{
f8c6f4e9	560	indio_dev->groups[indio_dev->groupcounter++] =
26d25ae3	561	&iio_trigger_consumer_attr_group;
1637db44	562	}
1637db44	563
f8c6f4e9	564	void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
1637db44	565	{
860c9c54	566	/* Clean up an associated but not attached trigger reference */
f8c6f4e9	567	if (indio_dev->trig)
7cbb7537	568	iio_trigger_put(indio_dev->trig);
1637db44	569	}
1637db44	570
3b99fb76	571	int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
c3db00cc	572	{
67be8e32 JC	573	return iio_trigger_attach_poll_func(indio_dev->trig,
67be8e32 JC	574	indio_dev->pollfunc);
c3db00cc	575	}
3b99fb76	576	EXPORT_SYMBOL(iio_triggered_buffer_postenable);
c3db00cc	577
3b99fb76	578	int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
c3db00cc	579	{
034bd7b5	580	return iio_trigger_detach_poll_func(indio_dev->trig,
67be8e32	581	indio_dev->pollfunc);
c3db00cc	582	}
3b99fb76	583	EXPORT_SYMBOL(iio_triggered_buffer_predisable);