[deliverable/linux.git] / drivers / staging / iio / industrialio-trigger.c

/* The industrial I/O core, trigger handling functions
 *
 * Copyright (c) 2008 Jonathan Cameron
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/idr.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/slab.h>

#include "iio.h"
#include "trigger.h"
#include "iio_core.h"
#include "iio_core_trigger.h"
#include "trigger_consumer.h"

/* RFC - Question of approach
 * Make the common case (single sensor single trigger)
 * simple by starting trigger capture from when first sensors
 * is added.
 *
 * Complex simultaneous start requires use of 'hold' functionality
 * of the trigger. (not implemented)
 *
 * Any other suggestions?
 */

static DEFINE_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 = dev_get_drvdata(dev);
	return sprintf(buf, "%s\n", trig->name);
}

static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);

/**
 * iio_trigger_register_sysfs() - create a device for this trigger
 * @trig_info:	the trigger
 *
 * Also adds any control attribute registered by the trigger driver
 **/
static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
{
	return sysfs_add_file_to_group(&trig_info->dev.kobj,
				       &dev_attr_name.attr,
				       NULL);
}

static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
{
	sysfs_remove_file_from_group(&trig_info->dev.kobj,
					   &dev_attr_name.attr,
					   NULL);
}

int iio_trigger_register(struct iio_trigger *trig_info)
{
	int ret;

	trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
	if (trig_info->id < 0) {
		ret = trig_info->id;
		goto error_ret;
	}
	/* Set the name used for the sysfs directory etc */
	dev_set_name(&trig_info->dev, "trigger%ld",
		     (unsigned long) trig_info->id);

	ret = device_add(&trig_info->dev);
	if (ret)
		goto error_unregister_id;

	ret = iio_trigger_register_sysfs(trig_info);
	if (ret)
		goto error_device_del;

	/* Add to list of available triggers held by the IIO core */
	mutex_lock(&iio_trigger_list_lock);
	list_add_tail(&trig_info->list, &iio_trigger_list);
	mutex_unlock(&iio_trigger_list_lock);

	return 0;

error_device_del:
	device_del(&trig_info->dev);
error_unregister_id:
	ida_simple_remove(&iio_trigger_ida, trig_info->id);
error_ret:
	return ret;
}
EXPORT_SYMBOL(iio_trigger_register);

void iio_trigger_unregister(struct iio_trigger *trig_info)
{
	mutex_lock(&iio_trigger_list_lock);
	list_del(&trig_info->list);
	mutex_unlock(&iio_trigger_list_lock);

	iio_trigger_unregister_sysfs(trig_info);
	ida_simple_remove(&iio_trigger_ida, trig_info->id);
	/* Possible issue in here */
	device_unregister(&trig_info->dev);
}
EXPORT_SYMBOL(iio_trigger_unregister);

static struct iio_trigger *iio_trigger_find_by_name(const char *name,
						    size_t len)
{
	struct iio_trigger *trig = NULL, *iter;

	mutex_lock(&iio_trigger_list_lock);
	list_for_each_entry(iter, &iio_trigger_list, list)
		if (sysfs_streq(iter->name, name)) {
			trig = iter;
			break;
		}
	mutex_unlock(&iio_trigger_list_lock);

	return trig;
}

void iio_trigger_poll(struct iio_trigger *trig, s64 time)
{
	int i;
	if (!trig->use_count)
		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
			if (trig->subirqs[i].enabled) {
				trig->use_count++;
				generic_handle_irq(trig->subirq_base + i);
			}
}
EXPORT_SYMBOL(iio_trigger_poll);

irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
{
	iio_trigger_poll(private, iio_get_time_ns());
	return IRQ_HANDLED;
}
EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);

void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
{
	int i;
	if (!trig->use_count)
		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
			if (trig->subirqs[i].enabled) {
				trig->use_count++;
				handle_nested_irq(trig->subirq_base + i);
			}
}
EXPORT_SYMBOL(iio_trigger_poll_chained);

void iio_trigger_notify_done(struct iio_trigger *trig)
{
	trig->use_count--;
	if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
		if (trig->ops->try_reenable(trig))
			/* Missed and interrupt so launch new poll now */
			iio_trigger_poll(trig, 0);
}
EXPORT_SYMBOL(iio_trigger_notify_done);

/* Trigger Consumer related functions */
static int iio_trigger_get_irq(struct iio_trigger *trig)
{
	int ret;
	mutex_lock(&trig->pool_lock);
	ret = bitmap_find_free_region(trig->pool,
				      CONFIG_IIO_CONSUMERS_PER_TRIGGER,
				      ilog2(1));
	mutex_unlock(&trig->pool_lock);
	if (ret >= 0)
		ret += trig->subirq_base;

	return ret;
}

static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
{
	mutex_lock(&trig->pool_lock);
	clear_bit(irq - trig->subirq_base, trig->pool);
	mutex_unlock(&trig->pool_lock);
}

/* Complexity in here.  With certain triggers (datardy) an acknowledgement
 * may be needed if the pollfuncs do not include the data read for the
 * triggering device.
 * This is not currently handled.  Alternative of not enabling trigger unless
 * the relevant function is in there may be the best option.
 */
/* Worth protecting against double additions?*/
static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
					struct iio_poll_func *pf)
{
	int ret = 0;
	bool notinuse
		= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);

	/* Prevent the module being removed whilst attached to a trigger */
	__module_get(pf->indio_dev->info->driver_module);
	pf->irq = iio_trigger_get_irq(trig);
	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
				   pf->type, pf->name,
				   pf);
	if (trig->ops && trig->ops->set_trigger_state && notinuse)
		ret = trig->ops->set_trigger_state(trig, true);

	return ret;
}

static int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
					 struct iio_poll_func *pf)
{
	int ret = 0;
	bool no_other_users
		= (bitmap_weight(trig->pool,
				 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
		   == 1);
	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
		ret = trig->ops->set_trigger_state(trig, false);
		if (ret)
			goto error_ret;
	}
	iio_trigger_put_irq(trig, pf->irq);
	free_irq(pf->irq, pf);
	module_put(pf->indio_dev->info->driver_module);

error_ret:
	return ret;
}

irqreturn_t iio_pollfunc_store_time(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	pf->timestamp = iio_get_time_ns();
	return IRQ_WAKE_THREAD;
}
EXPORT_SYMBOL(iio_pollfunc_store_time);

struct iio_poll_func
*iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
		    irqreturn_t (*thread)(int irq, void *p),
		    int type,
		    struct iio_dev *indio_dev,
		    const char *fmt,
		    ...)
{
	va_list vargs;
	struct iio_poll_func *pf;

	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	if (pf == NULL)
		return NULL;
	va_start(vargs, fmt);
	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	va_end(vargs);
	if (pf->name == NULL) {
		kfree(pf);
		return NULL;
	}
	pf->h = h;
	pf->thread = thread;
	pf->type = type;
	pf->indio_dev = indio_dev;

	return pf;
}
EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);

void iio_dealloc_pollfunc(struct iio_poll_func *pf)
{
	kfree(pf->name);
	kfree(pf);
}
EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);

/**
 * iio_trigger_read_currrent() - trigger consumer sysfs query which trigger
 *
 * For trigger consumers the current_trigger interface allows the trigger
 * used by the device to be queried.
 **/
static ssize_t iio_trigger_read_current(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	struct iio_dev *indio_dev = dev_get_drvdata(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_get_drvdata(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 (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_put_trigger(oldtrig);
	if (indio_dev->trig)
		iio_get_trigger(indio_dev->trig);

	return len;
}

static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR,
		   iio_trigger_read_current,
		   iio_trigger_write_current);

static struct attribute *iio_trigger_consumer_attrs[] = {
	&dev_attr_current_trigger.attr,
	NULL,
};

static const struct attribute_group iio_trigger_consumer_attr_group = {
	.name = "trigger",
	.attrs = iio_trigger_consumer_attrs,
};

static void iio_trig_release(struct device *device)
{
	struct iio_trigger *trig = to_iio_trigger(device);
	int i;

	if (trig->subirq_base) {
		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
			irq_modify_status(trig->subirq_base + i,
					  IRQ_NOAUTOEN,
					  IRQ_NOREQUEST | IRQ_NOPROBE);
			irq_set_chip(trig->subirq_base + i,
				     NULL);
			irq_set_handler(trig->subirq_base + i,
					NULL);
		}

		irq_free_descs(trig->subirq_base,
			       CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	}
	kfree(trig->name);
	kfree(trig);
}

static struct device_type iio_trig_type = {
	.release = iio_trig_release,
};

static void iio_trig_subirqmask(struct irq_data *d)
{
	struct irq_chip *chip = irq_data_get_irq_chip(d);
	struct iio_trigger *trig
		= container_of(chip,
			       struct iio_trigger, subirq_chip);
	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
}

static void iio_trig_subirqunmask(struct irq_data *d)
{
	struct irq_chip *chip = irq_data_get_irq_chip(d);
	struct iio_trigger *trig
		= container_of(chip,
			       struct iio_trigger, subirq_chip);
	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
}

struct iio_trigger *iio_allocate_trigger(const char *fmt, ...)
{
	va_list vargs;
	struct iio_trigger *trig;
	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	if (trig) {
		int i;
		trig->dev.type = &iio_trig_type;
		trig->dev.bus = &iio_bus_type;
		device_initialize(&trig->dev);
		dev_set_drvdata(&trig->dev, (void *)trig);

		mutex_init(&trig->pool_lock);
		trig->subirq_base
			= irq_alloc_descs(-1, 0,
					  CONFIG_IIO_CONSUMERS_PER_TRIGGER,
					  0);
		if (trig->subirq_base < 0) {
			kfree(trig);
			return NULL;
		}
		va_start(vargs, fmt);
		trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
		va_end(vargs);
		if (trig->name == NULL) {
			irq_free_descs(trig->subirq_base,
				       CONFIG_IIO_CONSUMERS_PER_TRIGGER);
			kfree(trig);
			return NULL;
		}
		trig->subirq_chip.name = trig->name;
		trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
		trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
		for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
			irq_set_chip(trig->subirq_base + i,
				     &trig->subirq_chip);
			irq_set_handler(trig->subirq_base + i,
					&handle_simple_irq);
			irq_modify_status(trig->subirq_base + i,
					  IRQ_NOREQUEST | IRQ_NOAUTOEN,
					  IRQ_NOPROBE);
		}
		get_device(&trig->dev);
	}
	return trig;
}
EXPORT_SYMBOL(iio_allocate_trigger);

void iio_free_trigger(struct iio_trigger *trig)
{
	if (trig)
		put_device(&trig->dev);
}
EXPORT_SYMBOL(iio_free_trigger);

void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
{
	indio_dev->groups[indio_dev->groupcounter++] =
		&iio_trigger_consumer_attr_group;
}

void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
{
	/* Clean up and associated but not attached triggers references */
	if (indio_dev->trig)
		iio_put_trigger(indio_dev->trig);
}

int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
{
	return iio_trigger_attach_poll_func(indio_dev->trig,
					    indio_dev->pollfunc);
}
EXPORT_SYMBOL(iio_triggered_buffer_postenable);

int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
{
	return iio_trigger_dettach_poll_func(indio_dev->trig,
					     indio_dev->pollfunc);
}
EXPORT_SYMBOL(iio_triggered_buffer_predisable);
Commit	Line	Data
1637db44 JC	1	/* The industrial I/O core, trigger handling functions
	2	*
	3	* Copyright (c) 2008 Jonathan Cameron
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License version 2 as published by
	7	* the Free Software Foundation.
	8	*/
	9
	10	#include <linux/kernel.h>
1637db44 JC	11	#include <linux/idr.h>
	12	#include <linux/err.h>
	13	#include <linux/device.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/list.h>
5a0e3ad6	16	#include <linux/slab.h>
1637db44 JC	17
	18	#include "iio.h"
	19	#include "trigger.h"
df9c1c42	20	#include "iio_core.h"
6aea1c36	21	#include "iio_core_trigger.h"
3f72395e	22	#include "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	{
	48	struct iio_trigger *trig = dev_get_drvdata(dev);
	49	return sprintf(buf, "%s\n", trig->name);
	50	}
	51
	52	static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL);
	53
1637db44 JC	54	/**
	55	* iio_trigger_register_sysfs() - create a device for this trigger
	56	* @trig_info: the trigger
	57	*
	58	* Also adds any control attribute registered by the trigger driver
	59	**/
	60	static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
	61	{
59c85e82 JC	62	return sysfs_add_file_to_group(&trig_info->dev.kobj,
	63	&dev_attr_name.attr,
	64	NULL);
1637db44 JC	65	}
	66
	67	static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
	68	{
59c85e82 JC	69	sysfs_remove_file_from_group(&trig_info->dev.kobj,
	70	&dev_attr_name.attr,
	71	NULL);
1637db44 JC	72	}
1637db44 JC	73
1637db44 JC	74	int iio_trigger_register(struct iio_trigger *trig_info)
	75	{
	76	int ret;
	77
47c24fdd JC	78	trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL);
	79	if (trig_info->id < 0) {
	80	ret = trig_info->id;
1637db44	81	goto error_ret;
47c24fdd	82	}
1637db44 JC	83	/* Set the name used for the sysfs directory etc */
	84	dev_set_name(&trig_info->dev, "trigger%ld",
	85	(unsigned long) trig_info->id);
	86
	87	ret = device_add(&trig_info->dev);
	88	if (ret)
	89	goto error_unregister_id;
	90
	91	ret = iio_trigger_register_sysfs(trig_info);
	92	if (ret)
	93	goto error_device_del;
	94
	95	/* Add to list of available triggers held by the IIO core */
	96	mutex_lock(&iio_trigger_list_lock);
	97	list_add_tail(&trig_info->list, &iio_trigger_list);
	98	mutex_unlock(&iio_trigger_list_lock);
	99
	100	return 0;
	101
	102	error_device_del:
	103	device_del(&trig_info->dev);
	104	error_unregister_id:
47c24fdd	105	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44 JC	106	error_ret:
	107	return ret;
	108	}
	109	EXPORT_SYMBOL(iio_trigger_register);
	110
	111	void iio_trigger_unregister(struct iio_trigger *trig_info)
	112	{
1637db44	113	mutex_lock(&iio_trigger_list_lock);
582e5489	114	list_del(&trig_info->list);
1637db44 JC	115	mutex_unlock(&iio_trigger_list_lock);
	116
	117	iio_trigger_unregister_sysfs(trig_info);
47c24fdd	118	ida_simple_remove(&iio_trigger_ida, trig_info->id);
1637db44 JC	119	/* Possible issue in here */
	120	device_unregister(&trig_info->dev);
	121	}
	122	EXPORT_SYMBOL(iio_trigger_unregister);
	123
f6517f22 JC	124	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	125	size_t len)
1637db44	126	{
f6517f22	127	struct iio_trigger trig = NULL, iter;
7c327857	128
1637db44	129	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	130	list_for_each_entry(iter, &iio_trigger_list, list)
	131	if (sysfs_streq(iter->name, name)) {
	132	trig = iter;
1637db44 JC	133	break;
1637db44 JC	134	}
1637db44 JC	135	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	136
f6517f22	137	return trig;
5f87404d	138	}
1637db44	139
7b2c33b1	140	void iio_trigger_poll(struct iio_trigger *trig, s64 time)
1637db44	141	{
d96d1337	142	int i;
cb6c89a0	143	if (!trig->use_count)
d96d1337 JC	144	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	145	if (trig->subirqs[i].enabled) {
	146	trig->use_count++;
	147	generic_handle_irq(trig->subirq_base + i);
	148	}
1637db44 JC	149	}
1637db44 JC	150	EXPORT_SYMBOL(iio_trigger_poll);
8384d957 JC	151
	152	irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private)
	153	{
	154	iio_trigger_poll(private, iio_get_time_ns());
	155	return IRQ_HANDLED;
	156	}
	157	EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll);
1637db44	158
1f785681 JC	159	void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time)
	160	{
	161	int i;
e69616b1	162	if (!trig->use_count)
1f785681 JC	163	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	164	if (trig->subirqs[i].enabled) {
	165	trig->use_count++;
	166	handle_nested_irq(trig->subirq_base + i);
	167	}
1f785681 JC	168	}
	169	EXPORT_SYMBOL(iio_trigger_poll_chained);
	170
1637db44 JC	171	void iio_trigger_notify_done(struct iio_trigger *trig)
	172	{
	173	trig->use_count--;
d29f73db	174	if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable)
e69616b1	175	if (trig->ops->try_reenable(trig))
1637db44	176	/* Missed and interrupt so launch new poll now */
7b2c33b1	177	iio_trigger_poll(trig, 0);
1637db44 JC	178	}
	179	EXPORT_SYMBOL(iio_trigger_notify_done);
	180
1637db44	181	/* Trigger Consumer related functions */
208b813c JC	182	static int iio_trigger_get_irq(struct iio_trigger *trig)
	183	{
	184	int ret;
	185	mutex_lock(&trig->pool_lock);
	186	ret = bitmap_find_free_region(trig->pool,
	187	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	188	ilog2(1));
	189	mutex_unlock(&trig->pool_lock);
	190	if (ret >= 0)
	191	ret += trig->subirq_base;
	192
	193	return ret;
	194	}
	195
	196	static void iio_trigger_put_irq(struct iio_trigger *trig, int irq)
	197	{
	198	mutex_lock(&trig->pool_lock);
	199	clear_bit(irq - trig->subirq_base, trig->pool);
	200	mutex_unlock(&trig->pool_lock);
	201	}
1637db44 JC	202
	203	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	204	* may be needed if the pollfuncs do not include the data read for the
	205	* triggering device.
	206	* This is not currently handled. Alternative of not enabling trigger unless
	207	* the relevant function is in there may be the best option.
	208	*/
	209	/* Worth protecting against double additions?*/
208b813c JC	210	static int iio_trigger_attach_poll_func(struct iio_trigger *trig,
208b813c JC	211	struct iio_poll_func *pf)
1637db44 JC	212	{
1637db44 JC	213	int ret = 0;
51c060a0 JC	214	bool notinuse
	215	= bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	216
f60c4a02 JC	217	/* Prevent the module being removed whilst attached to a trigger */
f60c4a02 JC	218	__module_get(pf->indio_dev->info->driver_module);
51c060a0 JC	219	pf->irq = iio_trigger_get_irq(trig);
	220	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	221	pf->type, pf->name,
	222	pf);
d29f73db JC	223	if (trig->ops && trig->ops->set_trigger_state && notinuse)
d29f73db JC	224	ret = trig->ops->set_trigger_state(trig, true);
d96d1337	225
1637db44 JC	226	return ret;
1637db44 JC	227	}
1637db44	228
208b813c JC	229	static int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
208b813c JC	230	struct iio_poll_func *pf)
1637db44	231	{
51c060a0 JC	232	int ret = 0;
	233	bool no_other_users
	234	= (bitmap_weight(trig->pool,
	235	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	236	== 1);
d29f73db JC	237	if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
d29f73db JC	238	ret = trig->ops->set_trigger_state(trig, false);
51c060a0 JC	239	if (ret)
51c060a0 JC	240	goto error_ret;
1637db44	241	}
51c060a0 JC	242	iio_trigger_put_irq(trig, pf->irq);
51c060a0 JC	243	free_irq(pf->irq, pf);
f60c4a02	244	module_put(pf->indio_dev->info->driver_module);
1637db44 JC	245
	246	error_ret:
	247	return ret;
	248	}
1637db44	249
d96d1337 JC	250	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	251	{
	252	struct iio_poll_func *pf = p;
	253	pf->timestamp = iio_get_time_ns();
	254	return IRQ_WAKE_THREAD;
	255	}
	256	EXPORT_SYMBOL(iio_pollfunc_store_time);
	257
21b185f8 JC	258	struct iio_poll_func
	259	iio_alloc_pollfunc(irqreturn_t (h)(int irq, void *p),
	260	irqreturn_t (thread)(int irq, void p),
	261	int type,
e65bc6ac	262	struct iio_dev *indio_dev,
21b185f8 JC	263	const char *fmt,
	264	...)
	265	{
	266	va_list vargs;
	267	struct iio_poll_func *pf;
	268
	269	pf = kmalloc(sizeof *pf, GFP_KERNEL);
	270	if (pf == NULL)
	271	return NULL;
	272	va_start(vargs, fmt);
	273	pf->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	274	va_end(vargs);
	275	if (pf->name == NULL) {
	276	kfree(pf);
	277	return NULL;
	278	}
	279	pf->h = h;
	280	pf->thread = thread;
	281	pf->type = type;
e65bc6ac	282	pf->indio_dev = indio_dev;
21b185f8 JC	283
	284	return pf;
	285	}
	286	EXPORT_SYMBOL_GPL(iio_alloc_pollfunc);
	287
	288	void iio_dealloc_pollfunc(struct iio_poll_func *pf)
	289	{
	290	kfree(pf->name);
	291	kfree(pf);
	292	}
	293	EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc);
	294
1637db44	295	/**
751a3700	296	* iio_trigger_read_currrent() - trigger consumer sysfs query which trigger
1637db44 JC	297	*
	298	* For trigger consumers the current_trigger interface allows the trigger
	299	* used by the device to be queried.
	300	**/
	301	static ssize_t iio_trigger_read_current(struct device *dev,
	302	struct device_attribute *attr,
	303	char *buf)
	304	{
f8c6f4e9	305	struct iio_dev *indio_dev = dev_get_drvdata(dev);
cb6c89a0	306
f8c6f4e9 JC	307	if (indio_dev->trig)
f8c6f4e9 JC	308	return sprintf(buf, "%s\n", indio_dev->trig->name);
cb6c89a0	309	return 0;
1637db44 JC	310	}
	311
	312	/**
	313	* iio_trigger_write_current() trigger consumer sysfs set current trigger
	314	*
	315	* For trigger consumers the current_trigger interface allows the trigger
	316	* used for this device to be specified at run time based on the triggers
	317	* name.
	318	**/
	319	static ssize_t iio_trigger_write_current(struct device *dev,
	320	struct device_attribute *attr,
	321	const char *buf,
	322	size_t len)
	323	{
f8c6f4e9 JC	324	struct iio_dev *indio_dev = dev_get_drvdata(dev);
f8c6f4e9 JC	325	struct iio_trigger *oldtrig = indio_dev->trig;
43a4360e MH	326	struct iio_trigger *trig;
	327	int ret;
	328
f8c6f4e9 JC	329	mutex_lock(&indio_dev->mlock);
	330	if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
	331	mutex_unlock(&indio_dev->mlock);
1637db44 JC	332	return -EBUSY;
1637db44 JC	333	}
f8c6f4e9	334	mutex_unlock(&indio_dev->mlock);
1637db44	335
43a4360e MH	336	trig = iio_trigger_find_by_name(buf, len);
43a4360e MH	337
f8c6f4e9 JC	338	if (trig && indio_dev->info->validate_trigger) {
f8c6f4e9 JC	339	ret = indio_dev->info->validate_trigger(indio_dev, trig);
43a4360e MH	340	if (ret)
	341	return ret;
	342	}
	343
d29f73db	344	if (trig && trig->ops && trig->ops->validate_device) {
f8c6f4e9	345	ret = trig->ops->validate_device(trig, indio_dev);
43a4360e MH	346	if (ret)
	347	return ret;
	348	}
	349
f8c6f4e9	350	indio_dev->trig = trig;
43a4360e	351
f8c6f4e9	352	if (oldtrig && indio_dev->trig != oldtrig)
1637db44	353	iio_put_trigger(oldtrig);
f8c6f4e9 JC	354	if (indio_dev->trig)
f8c6f4e9 JC	355	iio_get_trigger(indio_dev->trig);
1637db44 JC	356
	357	return len;
	358	}
	359
74112d3f GKH	360	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	361	iio_trigger_read_current,
	362	iio_trigger_write_current);
1637db44 JC	363
	364	static struct attribute *iio_trigger_consumer_attrs[] = {
	365	&dev_attr_current_trigger.attr,
	366	NULL,
	367	};
	368
	369	static const struct attribute_group iio_trigger_consumer_attr_group = {
	370	.name = "trigger",
	371	.attrs = iio_trigger_consumer_attrs,
	372	};
	373
	374	static void iio_trig_release(struct device *device)
	375	{
	376	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	377	int i;
	378
	379	if (trig->subirq_base) {
	380	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	381	irq_modify_status(trig->subirq_base + i,
	382	IRQ_NOAUTOEN,
	383	IRQ_NOREQUEST \| IRQ_NOPROBE);
	384	irq_set_chip(trig->subirq_base + i,
	385	NULL);
	386	irq_set_handler(trig->subirq_base + i,
	387	NULL);
	388	}
	389
	390	irq_free_descs(trig->subirq_base,
	391	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	392	}
59c85e82	393	kfree(trig->name);
1637db44	394	kfree(trig);
1637db44 JC	395	}
	396
	397	static struct device_type iio_trig_type = {
	398	.release = iio_trig_release,
	399	};
	400
d96d1337 JC	401	static void iio_trig_subirqmask(struct irq_data *d)
	402	{
	403	struct irq_chip *chip = irq_data_get_irq_chip(d);
	404	struct iio_trigger *trig
	405	= container_of(chip,
	406	struct iio_trigger, subirq_chip);
	407	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	408	}
	409
	410	static void iio_trig_subirqunmask(struct irq_data *d)
	411	{
	412	struct irq_chip *chip = irq_data_get_irq_chip(d);
	413	struct iio_trigger *trig
	414	= container_of(chip,
	415	struct iio_trigger, subirq_chip);
	416	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	417	}
	418
59c85e82	419	struct iio_trigger iio_allocate_trigger(const char fmt, ...)
1637db44	420	{
59c85e82	421	va_list vargs;
1637db44 JC	422	struct iio_trigger *trig;
	423	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	424	if (trig) {
d96d1337	425	int i;
1637db44	426	trig->dev.type = &iio_trig_type;
5aaaeba8	427	trig->dev.bus = &iio_bus_type;
1637db44 JC	428	device_initialize(&trig->dev);
1637db44 JC	429	dev_set_drvdata(&trig->dev, (void *)trig);
d96d1337	430
59c85e82 JC	431	mutex_init(&trig->pool_lock);
	432	trig->subirq_base
	433	= irq_alloc_descs(-1, 0,
	434	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	435	0);
	436	if (trig->subirq_base < 0) {
	437	kfree(trig);
	438	return NULL;
	439	}
	440	va_start(vargs, fmt);
	441	trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
	442	va_end(vargs);
	443	if (trig->name == NULL) {
	444	irq_free_descs(trig->subirq_base,
	445	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	446	kfree(trig);
	447	return NULL;
	448	}
	449	trig->subirq_chip.name = trig->name;
	450	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	451	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	452	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	453	irq_set_chip(trig->subirq_base + i,
	454	&trig->subirq_chip);
	455	irq_set_handler(trig->subirq_base + i,
	456	&handle_simple_irq);
	457	irq_modify_status(trig->subirq_base + i,
	458	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	459	IRQ_NOPROBE);
d96d1337	460	}
5f9c035c	461	get_device(&trig->dev);
1637db44 JC	462	}
	463	return trig;
	464	}
	465	EXPORT_SYMBOL(iio_allocate_trigger);
	466
	467	void iio_free_trigger(struct iio_trigger *trig)
	468	{
	469	if (trig)
	470	put_device(&trig->dev);
	471	}
	472	EXPORT_SYMBOL(iio_free_trigger);
	473
67be8e32	474	void iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
1637db44	475	{
f8c6f4e9	476	indio_dev->groups[indio_dev->groupcounter++] =
26d25ae3	477	&iio_trigger_consumer_attr_group;
1637db44	478	}
1637db44	479
f8c6f4e9	480	void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev)
1637db44	481	{
5f9c035c	482	/* Clean up and associated but not attached triggers references */
f8c6f4e9 JC	483	if (indio_dev->trig)
f8c6f4e9 JC	484	iio_put_trigger(indio_dev->trig);
1637db44	485	}
1637db44	486
3b99fb76	487	int iio_triggered_buffer_postenable(struct iio_dev *indio_dev)
c3db00cc	488	{
67be8e32 JC	489	return iio_trigger_attach_poll_func(indio_dev->trig,
67be8e32 JC	490	indio_dev->pollfunc);
c3db00cc	491	}
3b99fb76	492	EXPORT_SYMBOL(iio_triggered_buffer_postenable);
c3db00cc	493
3b99fb76	494	int iio_triggered_buffer_predisable(struct iio_dev *indio_dev)
c3db00cc	495	{
67be8e32 JC	496	return iio_trigger_dettach_poll_func(indio_dev->trig,
67be8e32 JC	497	indio_dev->pollfunc);
c3db00cc	498	}
3b99fb76	499	EXPORT_SYMBOL(iio_triggered_buffer_predisable);