[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/module.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 "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_IDR(iio_trigger_idr);
static DEFINE_SPINLOCK(iio_trigger_idr_lock);

/* Single list of all available triggers */
static LIST_HEAD(iio_trigger_list);
static DEFINE_MUTEX(iio_trigger_list_lock);

/**
 * 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)
{
	int ret = 0;

	if (trig_info->control_attrs)
		ret = sysfs_create_group(&trig_info->dev.kobj,
					 trig_info->control_attrs);

	return ret;
}

static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
{
	if (trig_info->control_attrs)
		sysfs_remove_group(&trig_info->dev.kobj,
				   trig_info->control_attrs);
}


/**
 * iio_trigger_register_id() - get a unique id for this trigger
 * @trig_info:	the trigger
 **/
static int iio_trigger_register_id(struct iio_trigger *trig_info)
{
	int ret = 0;

idr_again:
	if (unlikely(idr_pre_get(&iio_trigger_idr, GFP_KERNEL) == 0))
		return -ENOMEM;

	spin_lock(&iio_trigger_idr_lock);
	ret = idr_get_new(&iio_trigger_idr, NULL, &trig_info->id);
	spin_unlock(&iio_trigger_idr_lock);
	if (unlikely(ret == -EAGAIN))
		goto idr_again;
	else if (likely(!ret))
		trig_info->id = trig_info->id & MAX_ID_MASK;

	return ret;
}

/**
 * iio_trigger_unregister_id() - free up unique id for use by another trigger
 * @trig_info: the trigger
 **/
static void iio_trigger_unregister_id(struct iio_trigger *trig_info)
{
	spin_lock(&iio_trigger_idr_lock);
	idr_remove(&iio_trigger_idr, trig_info->id);
	spin_unlock(&iio_trigger_idr_lock);
}

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

	ret = iio_trigger_register_id(trig_info);
	if (ret)
		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:
	iio_trigger_unregister_id(trig_info);
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);
	iio_trigger_unregister_id(trig_info);
	/* 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;
	struct iio_poll_func *pf_cursor;

	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
		if (pf_cursor->poll_func_immediate) {
			pf_cursor->poll_func_immediate(pf_cursor->private_data);
			trig->use_count++;
		}
	}
	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
		if (pf_cursor->poll_func_main) {
			pf_cursor->poll_func_main(pf_cursor->private_data,
						  time);
			trig->use_count++;
		}
	}
	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);

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

/**
 * iio_trigger_read_name() - retrieve useful identifying name
 **/
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);
}
EXPORT_SYMBOL(iio_trigger_read_name);

/* Trigger Consumer related functions */

/* 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?*/
int iio_trigger_attach_poll_func(struct iio_trigger *trig,
				 struct iio_poll_func *pf)
{
	int ret = 0;
	unsigned long flags;

	if (pf->thread) {
		bool notinuse
			= bitmap_empty(trig->pool,
				       CONFIG_IIO_CONSUMERS_PER_TRIGGER);

		pf->irq = iio_trigger_get_irq(trig);
		ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
					   pf->type, pf->name,
					   pf);
		if (trig->set_trigger_state && notinuse) {
			ret = trig->set_trigger_state(trig, true);
	} else {
		spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
		list_add_tail(&pf->list, &trig->pollfunc_list);
		spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);

		if (trig->set_trigger_state)
			ret = trig->set_trigger_state(trig, true);
		}
		if (ret) {
			printk(KERN_ERR "set trigger state failed\n");
			list_del(&pf->list);
		}
	}

	return ret;
}
EXPORT_SYMBOL(iio_trigger_attach_poll_func);

int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
				  struct iio_poll_func *pf)
{
	struct iio_poll_func *pf_cursor;
	unsigned long flags;
	int ret = -EINVAL;

	if (pf->thread) {
		bool no_other_users
			= (bitmap_weight(trig->pool,
					 CONFIG_IIO_CONSUMERS_PER_TRIGGER)
			   == 1);
		if (trig->set_trigger_state && no_other_users) {
			ret = trig->set_trigger_state(trig, false);
			if (ret)
				goto error_ret;
		} else
			ret = 0;
		iio_trigger_put_irq(trig, pf->irq);
		free_irq(pf->irq, pf);
	} else {
		spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
		list_for_each_entry(pf_cursor, &trig->pollfunc_list, list)
			if (pf_cursor == pf) {
				ret = 0;
				break;
			}
		if (!ret) {
			if (list_is_singular(&trig->pollfunc_list)
			    && trig->set_trigger_state) {
				spin_unlock_irqrestore(&trig
						       ->pollfunc_list_lock,
						       flags);
				/* May sleep hence cannot hold the spin lock */
				ret = trig->set_trigger_state(trig, false);
				if (ret)
					goto error_ret;
				spin_lock_irqsave(&trig->pollfunc_list_lock,
						  flags);
			}
			/*
			 * Now we can delete safe in the knowledge that, if
			 * this is the last pollfunc then we have disabled
			 * the trigger anyway and so nothing should be able
			 * to call the pollfunc.
			 */
			list_del(&pf_cursor->list);
		}
		spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
	}

error_ret:
	return ret;
}
EXPORT_SYMBOL(iio_trigger_dettach_poll_func);

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);

/**
 * 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 *dev_info = dev_get_drvdata(dev);
	int len = 0;
	if (dev_info->trig)
		len = sprintf(buf,
			      "%s\n",
			      dev_info->trig->name);
	return len;
}

/**
 * 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 *dev_info = dev_get_drvdata(dev);
	struct iio_trigger *oldtrig = dev_info->trig;
	mutex_lock(&dev_info->mlock);
	if (dev_info->currentmode == INDIO_RING_TRIGGERED) {
		mutex_unlock(&dev_info->mlock);
		return -EBUSY;
	}
	mutex_unlock(&dev_info->mlock);

	dev_info->trig = iio_trigger_find_by_name(buf, len);
	if (oldtrig && dev_info->trig != oldtrig)
		iio_put_trigger(oldtrig);
	if (dev_info->trig)
		iio_get_trigger(dev_info->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);
	iio_put();
}

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_named(const char *name)
{
	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);
		spin_lock_init(&trig->pollfunc_list_lock);
		INIT_LIST_HEAD(&trig->list);
		INIT_LIST_HEAD(&trig->pollfunc_list);

		if (name) {
			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 = name;
			trig->subirq_chip.name = 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);
			}
		}
		iio_get();
	}
	return trig;
}
EXPORT_SYMBOL(iio_allocate_trigger_named);

struct iio_trigger *iio_allocate_trigger(void)
{
	return iio_allocate_trigger_named(NULL);
}
EXPORT_SYMBOL(iio_allocate_trigger);

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

int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
{
	int ret;
	ret = sysfs_create_group(&dev_info->dev.kobj,
				 &iio_trigger_consumer_attr_group);
	return ret;
}
EXPORT_SYMBOL(iio_device_register_trigger_consumer);

int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
{
	sysfs_remove_group(&dev_info->dev.kobj,
			   &iio_trigger_consumer_attr_group);
	return 0;
}
EXPORT_SYMBOL(iio_device_unregister_trigger_consumer);

int iio_alloc_pollfunc(struct iio_dev *indio_dev,
		       void (*immediate)(struct iio_dev *indio_dev),
		       void (*main)(struct iio_dev *private_data, s64 time))
{
	indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
	if (indio_dev->pollfunc == NULL)
		return -ENOMEM;
	indio_dev->pollfunc->poll_func_immediate = immediate;
	indio_dev->pollfunc->poll_func_main = main;
	indio_dev->pollfunc->private_data = indio_dev;
	return 0;
}
EXPORT_SYMBOL(iio_alloc_pollfunc);

int iio_triggered_ring_postenable(struct iio_dev *indio_dev)
{
	return indio_dev->trig
		? iio_trigger_attach_poll_func(indio_dev->trig,
					       indio_dev->pollfunc)
		: 0;
}
EXPORT_SYMBOL(iio_triggered_ring_postenable);

int iio_triggered_ring_predisable(struct iio_dev *indio_dev)
{
	return indio_dev->trig
		? iio_trigger_dettach_poll_func(indio_dev->trig,
						indio_dev->pollfunc)
		: 0;
}
EXPORT_SYMBOL(iio_triggered_ring_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>
	11	#include <linux/module.h>
	12	#include <linux/idr.h>
	13	#include <linux/err.h>
	14	#include <linux/device.h>
	15	#include <linux/interrupt.h>
	16	#include <linux/list.h>
5a0e3ad6	17	#include <linux/slab.h>
1637db44 JC	18
	19	#include "iio.h"
	20	#include "trigger.h"
74112d3f	21	#include "trigger_consumer.h"
1637db44 JC	22
	23	/* RFC - Question of approach
	24	* Make the common case (single sensor single trigger)
	25	* simple by starting trigger capture from when first sensors
	26	* is added.
	27	*
	28	* Complex simultaneous start requires use of 'hold' functionality
	29	* of the trigger. (not implemented)
	30	*
	31	* Any other suggestions?
	32	*/
	33
1637db44 JC	34	static DEFINE_IDR(iio_trigger_idr);
	35	static DEFINE_SPINLOCK(iio_trigger_idr_lock);
	36
	37	/* Single list of all available triggers */
	38	static LIST_HEAD(iio_trigger_list);
	39	static DEFINE_MUTEX(iio_trigger_list_lock);
	40
	41	/**
	42	* iio_trigger_register_sysfs() - create a device for this trigger
	43	* @trig_info: the trigger
	44	*
	45	* Also adds any control attribute registered by the trigger driver
	46	**/
	47	static int iio_trigger_register_sysfs(struct iio_trigger *trig_info)
	48	{
	49	int ret = 0;
	50
	51	if (trig_info->control_attrs)
	52	ret = sysfs_create_group(&trig_info->dev.kobj,
	53	trig_info->control_attrs);
	54
	55	return ret;
	56	}
	57
	58	static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info)
	59	{
	60	if (trig_info->control_attrs)
	61	sysfs_remove_group(&trig_info->dev.kobj,
	62	trig_info->control_attrs);
	63	}
	64
	65
	66	/**
	67	* iio_trigger_register_id() - get a unique id for this trigger
	68	* @trig_info: the trigger
	69	**/
	70	static int iio_trigger_register_id(struct iio_trigger *trig_info)
	71	{
	72	int ret = 0;
	73
	74	idr_again:
	75	if (unlikely(idr_pre_get(&iio_trigger_idr, GFP_KERNEL) == 0))
	76	return -ENOMEM;
	77
	78	spin_lock(&iio_trigger_idr_lock);
	79	ret = idr_get_new(&iio_trigger_idr, NULL, &trig_info->id);
	80	spin_unlock(&iio_trigger_idr_lock);
	81	if (unlikely(ret == -EAGAIN))
	82	goto idr_again;
	83	else if (likely(!ret))
	84	trig_info->id = trig_info->id & MAX_ID_MASK;
	85
	86	return ret;
	87	}
	88
	89	/**
	90	* iio_trigger_unregister_id() - free up unique id for use by another trigger
	91	* @trig_info: the trigger
	92	**/
	93	static void iio_trigger_unregister_id(struct iio_trigger *trig_info)
	94	{
74112d3f GKH	95	spin_lock(&iio_trigger_idr_lock);
	96	idr_remove(&iio_trigger_idr, trig_info->id);
	97	spin_unlock(&iio_trigger_idr_lock);
1637db44 JC	98	}
	99
	100	int iio_trigger_register(struct iio_trigger *trig_info)
	101	{
	102	int ret;
	103
	104	ret = iio_trigger_register_id(trig_info);
	105	if (ret)
	106	goto error_ret;
	107	/* Set the name used for the sysfs directory etc */
	108	dev_set_name(&trig_info->dev, "trigger%ld",
	109	(unsigned long) trig_info->id);
	110
	111	ret = device_add(&trig_info->dev);
	112	if (ret)
	113	goto error_unregister_id;
	114
	115	ret = iio_trigger_register_sysfs(trig_info);
	116	if (ret)
	117	goto error_device_del;
	118
	119	/* Add to list of available triggers held by the IIO core */
	120	mutex_lock(&iio_trigger_list_lock);
	121	list_add_tail(&trig_info->list, &iio_trigger_list);
	122	mutex_unlock(&iio_trigger_list_lock);
	123
	124	return 0;
	125
	126	error_device_del:
	127	device_del(&trig_info->dev);
	128	error_unregister_id:
	129	iio_trigger_unregister_id(trig_info);
	130	error_ret:
	131	return ret;
	132	}
	133	EXPORT_SYMBOL(iio_trigger_register);
	134
	135	void iio_trigger_unregister(struct iio_trigger *trig_info)
	136	{
1637db44	137	mutex_lock(&iio_trigger_list_lock);
582e5489	138	list_del(&trig_info->list);
1637db44 JC	139	mutex_unlock(&iio_trigger_list_lock);
	140
	141	iio_trigger_unregister_sysfs(trig_info);
	142	iio_trigger_unregister_id(trig_info);
	143	/* Possible issue in here */
	144	device_unregister(&trig_info->dev);
	145	}
	146	EXPORT_SYMBOL(iio_trigger_unregister);
	147
f6517f22 JC	148	static struct iio_trigger iio_trigger_find_by_name(const char name,
f6517f22 JC	149	size_t len)
1637db44	150	{
f6517f22	151	struct iio_trigger trig = NULL, iter;
7c327857	152
1637db44	153	mutex_lock(&iio_trigger_list_lock);
f6517f22 JC	154	list_for_each_entry(iter, &iio_trigger_list, list)
	155	if (sysfs_streq(iter->name, name)) {
	156	trig = iter;
1637db44 JC	157	break;
1637db44 JC	158	}
1637db44 JC	159	mutex_unlock(&iio_trigger_list_lock);
1637db44 JC	160
f6517f22	161	return trig;
5f87404d	162	}
1637db44	163
7b2c33b1	164	void iio_trigger_poll(struct iio_trigger *trig, s64 time)
1637db44	165	{
d96d1337	166	int i;
1637db44 JC	167	struct iio_poll_func *pf_cursor;
	168
	169	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
	170	if (pf_cursor->poll_func_immediate) {
	171	pf_cursor->poll_func_immediate(pf_cursor->private_data);
	172	trig->use_count++;
	173	}
	174	}
	175	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list) {
	176	if (pf_cursor->poll_func_main) {
7b2c33b1 JC	177	pf_cursor->poll_func_main(pf_cursor->private_data,
7b2c33b1 JC	178	time);
1637db44 JC	179	trig->use_count++;
	180	}
	181	}
d96d1337 JC	182	if (!trig->use_count) {
	183	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++)
	184	if (trig->subirqs[i].enabled) {
	185	trig->use_count++;
	186	generic_handle_irq(trig->subirq_base + i);
	187	}
	188	}
1637db44 JC	189	}
	190	EXPORT_SYMBOL(iio_trigger_poll);
	191
	192	void iio_trigger_notify_done(struct iio_trigger *trig)
	193	{
	194	trig->use_count--;
	195	if (trig->use_count == 0 && trig->try_reenable)
	196	if (trig->try_reenable(trig)) {
	197	/* Missed and interrupt so launch new poll now */
7b2c33b1	198	iio_trigger_poll(trig, 0);
1637db44 JC	199	}
	200	}
	201	EXPORT_SYMBOL(iio_trigger_notify_done);
	202
	203	/**
	204	* iio_trigger_read_name() - retrieve useful identifying name
	205	**/
	206	ssize_t iio_trigger_read_name(struct device *dev,
	207	struct device_attribute *attr,
	208	char *buf)
	209	{
	210	struct iio_trigger *trig = dev_get_drvdata(dev);
	211	return sprintf(buf, "%s\n", trig->name);
	212	}
	213	EXPORT_SYMBOL(iio_trigger_read_name);
	214
	215	/* Trigger Consumer related functions */
	216
	217	/* Complexity in here. With certain triggers (datardy) an acknowledgement
	218	* may be needed if the pollfuncs do not include the data read for the
	219	* triggering device.
	220	* This is not currently handled. Alternative of not enabling trigger unless
	221	* the relevant function is in there may be the best option.
	222	*/
	223	/* Worth protecting against double additions?*/
	224	int iio_trigger_attach_poll_func(struct iio_trigger *trig,
	225	struct iio_poll_func *pf)
	226	{
	227	int ret = 0;
	228	unsigned long flags;
	229
d96d1337 JC	230	if (pf->thread) {
	231	bool notinuse
	232	= bitmap_empty(trig->pool,
	233	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	234
	235	pf->irq = iio_trigger_get_irq(trig);
	236	ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
	237	pf->type, pf->name,
	238	pf);
	239	if (trig->set_trigger_state && notinuse) {
	240	ret = trig->set_trigger_state(trig, true);
	241	} else {
	242	spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
	243	list_add_tail(&pf->list, &trig->pollfunc_list);
	244	spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
	245
	246	if (trig->set_trigger_state)
	247	ret = trig->set_trigger_state(trig, true);
	248	}
	249	if (ret) {
	250	printk(KERN_ERR "set trigger state failed\n");
	251	list_del(&pf->list);
	252	}
1637db44	253	}
d96d1337	254
1637db44 JC	255	return ret;
	256	}
	257	EXPORT_SYMBOL(iio_trigger_attach_poll_func);
	258
	259	int iio_trigger_dettach_poll_func(struct iio_trigger *trig,
	260	struct iio_poll_func *pf)
	261	{
	262	struct iio_poll_func *pf_cursor;
	263	unsigned long flags;
	264	int ret = -EINVAL;
	265
d96d1337 JC	266	if (pf->thread) {
	267	bool no_other_users
	268	= (bitmap_weight(trig->pool,
	269	CONFIG_IIO_CONSUMERS_PER_TRIGGER)
	270	== 1);
	271	if (trig->set_trigger_state && no_other_users) {
1637db44 JC	272	ret = trig->set_trigger_state(trig, false);
	273	if (ret)
	274	goto error_ret;
d96d1337 JC	275	} else
	276	ret = 0;
	277	iio_trigger_put_irq(trig, pf->irq);
	278	free_irq(pf->irq, pf);
	279	} else {
	280	spin_lock_irqsave(&trig->pollfunc_list_lock, flags);
	281	list_for_each_entry(pf_cursor, &trig->pollfunc_list, list)
	282	if (pf_cursor == pf) {
	283	ret = 0;
	284	break;
	285	}
	286	if (!ret) {
	287	if (list_is_singular(&trig->pollfunc_list)
	288	&& trig->set_trigger_state) {
	289	spin_unlock_irqrestore(&trig
	290	->pollfunc_list_lock,
	291	flags);
	292	/* May sleep hence cannot hold the spin lock */
	293	ret = trig->set_trigger_state(trig, false);
	294	if (ret)
	295	goto error_ret;
	296	spin_lock_irqsave(&trig->pollfunc_list_lock,
	297	flags);
	298	}
	299	/*
	300	* Now we can delete safe in the knowledge that, if
	301	* this is the last pollfunc then we have disabled
	302	* the trigger anyway and so nothing should be able
	303	* to call the pollfunc.
	304	*/
	305	list_del(&pf_cursor->list);
1637db44	306	}
d96d1337	307	spin_unlock_irqrestore(&trig->pollfunc_list_lock, flags);
1637db44	308	}
1637db44 JC	309
	310	error_ret:
	311	return ret;
	312	}
	313	EXPORT_SYMBOL(iio_trigger_dettach_poll_func);
	314
d96d1337 JC	315	irqreturn_t iio_pollfunc_store_time(int irq, void *p)
	316	{
	317	struct iio_poll_func *pf = p;
	318	pf->timestamp = iio_get_time_ns();
	319	return IRQ_WAKE_THREAD;
	320	}
	321	EXPORT_SYMBOL(iio_pollfunc_store_time);
	322
1637db44	323	/**
751a3700	324	* iio_trigger_read_currrent() - trigger consumer sysfs query which trigger
1637db44 JC	325	*
	326	* For trigger consumers the current_trigger interface allows the trigger
	327	* used by the device to be queried.
	328	**/
	329	static ssize_t iio_trigger_read_current(struct device *dev,
	330	struct device_attribute *attr,
	331	char *buf)
	332	{
	333	struct iio_dev *dev_info = dev_get_drvdata(dev);
	334	int len = 0;
	335	if (dev_info->trig)
3c9bbf58 JC	336	len = sprintf(buf,
	337	"%s\n",
	338	dev_info->trig->name);
1637db44 JC	339	return len;
	340	}
	341
	342	/**
	343	* iio_trigger_write_current() trigger consumer sysfs set current trigger
	344	*
	345	* For trigger consumers the current_trigger interface allows the trigger
	346	* used for this device to be specified at run time based on the triggers
	347	* name.
	348	**/
	349	static ssize_t iio_trigger_write_current(struct device *dev,
	350	struct device_attribute *attr,
	351	const char *buf,
	352	size_t len)
	353	{
	354	struct iio_dev *dev_info = dev_get_drvdata(dev);
	355	struct iio_trigger *oldtrig = dev_info->trig;
	356	mutex_lock(&dev_info->mlock);
	357	if (dev_info->currentmode == INDIO_RING_TRIGGERED) {
	358	mutex_unlock(&dev_info->mlock);
	359	return -EBUSY;
	360	}
	361	mutex_unlock(&dev_info->mlock);
	362
1637db44 JC	363	dev_info->trig = iio_trigger_find_by_name(buf, len);
	364	if (oldtrig && dev_info->trig != oldtrig)
	365	iio_put_trigger(oldtrig);
	366	if (dev_info->trig)
	367	iio_get_trigger(dev_info->trig);
	368
	369	return len;
	370	}
	371
74112d3f GKH	372	static DEVICE_ATTR(current_trigger, S_IRUGO \| S_IWUSR,
	373	iio_trigger_read_current,
	374	iio_trigger_write_current);
1637db44 JC	375
	376	static struct attribute *iio_trigger_consumer_attrs[] = {
	377	&dev_attr_current_trigger.attr,
	378	NULL,
	379	};
	380
	381	static const struct attribute_group iio_trigger_consumer_attr_group = {
	382	.name = "trigger",
	383	.attrs = iio_trigger_consumer_attrs,
	384	};
	385
	386	static void iio_trig_release(struct device *device)
	387	{
	388	struct iio_trigger *trig = to_iio_trigger(device);
d96d1337 JC	389	int i;
	390
	391	if (trig->subirq_base) {
	392	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	393	irq_modify_status(trig->subirq_base + i,
	394	IRQ_NOAUTOEN,
	395	IRQ_NOREQUEST \| IRQ_NOPROBE);
	396	irq_set_chip(trig->subirq_base + i,
	397	NULL);
	398	irq_set_handler(trig->subirq_base + i,
	399	NULL);
	400	}
	401
	402	irq_free_descs(trig->subirq_base,
	403	CONFIG_IIO_CONSUMERS_PER_TRIGGER);
	404	}
1637db44 JC	405	kfree(trig);
	406	iio_put();
	407	}
	408
	409	static struct device_type iio_trig_type = {
	410	.release = iio_trig_release,
	411	};
	412
d96d1337 JC	413	static void iio_trig_subirqmask(struct irq_data *d)
	414	{
	415	struct irq_chip *chip = irq_data_get_irq_chip(d);
	416	struct iio_trigger *trig
	417	= container_of(chip,
	418	struct iio_trigger, subirq_chip);
	419	trig->subirqs[d->irq - trig->subirq_base].enabled = false;
	420	}
	421
	422	static void iio_trig_subirqunmask(struct irq_data *d)
	423	{
	424	struct irq_chip *chip = irq_data_get_irq_chip(d);
	425	struct iio_trigger *trig
	426	= container_of(chip,
	427	struct iio_trigger, subirq_chip);
	428	trig->subirqs[d->irq - trig->subirq_base].enabled = true;
	429	}
	430
	431	struct iio_trigger iio_allocate_trigger_named(const char name)
1637db44 JC	432	{
	433	struct iio_trigger *trig;
	434	trig = kzalloc(sizeof *trig, GFP_KERNEL);
	435	if (trig) {
d96d1337	436	int i;
1637db44	437	trig->dev.type = &iio_trig_type;
5aaaeba8	438	trig->dev.bus = &iio_bus_type;
1637db44 JC	439	device_initialize(&trig->dev);
	440	dev_set_drvdata(&trig->dev, (void *)trig);
	441	spin_lock_init(&trig->pollfunc_list_lock);
	442	INIT_LIST_HEAD(&trig->list);
	443	INIT_LIST_HEAD(&trig->pollfunc_list);
d96d1337 JC	444
	445	if (name) {
	446	mutex_init(&trig->pool_lock);
	447	trig->subirq_base
	448	= irq_alloc_descs(-1, 0,
	449	CONFIG_IIO_CONSUMERS_PER_TRIGGER,
	450	0);
	451	if (trig->subirq_base < 0) {
	452	kfree(trig);
	453	return NULL;
	454	}
	455	trig->name = name;
	456	trig->subirq_chip.name = name;
	457	trig->subirq_chip.irq_mask = &iio_trig_subirqmask;
	458	trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask;
	459	for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) {
	460	irq_set_chip(trig->subirq_base + i,
	461	&trig->subirq_chip);
	462	irq_set_handler(trig->subirq_base + i,
	463	&handle_simple_irq);
	464	irq_modify_status(trig->subirq_base + i,
	465	IRQ_NOREQUEST \| IRQ_NOAUTOEN,
	466	IRQ_NOPROBE);
	467	}
	468	}
1637db44 JC	469	iio_get();
	470	}
	471	return trig;
	472	}
d96d1337 JC	473	EXPORT_SYMBOL(iio_allocate_trigger_named);
	474
	475	struct iio_trigger *iio_allocate_trigger(void)
	476	{
	477	return iio_allocate_trigger_named(NULL);
	478	}
1637db44 JC	479	EXPORT_SYMBOL(iio_allocate_trigger);
	480
	481	void iio_free_trigger(struct iio_trigger *trig)
	482	{
	483	if (trig)
	484	put_device(&trig->dev);
	485	}
	486	EXPORT_SYMBOL(iio_free_trigger);
	487
	488	int iio_device_register_trigger_consumer(struct iio_dev *dev_info)
	489	{
	490	int ret;
	491	ret = sysfs_create_group(&dev_info->dev.kobj,
	492	&iio_trigger_consumer_attr_group);
	493	return ret;
	494	}
	495	EXPORT_SYMBOL(iio_device_register_trigger_consumer);
	496
	497	int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info)
	498	{
	499	sysfs_remove_group(&dev_info->dev.kobj,
	500	&iio_trigger_consumer_attr_group);
	501	return 0;
	502	}
	503	EXPORT_SYMBOL(iio_device_unregister_trigger_consumer);
	504
15744090 JC	505	int iio_alloc_pollfunc(struct iio_dev *indio_dev,
15744090 JC	506	void (immediate)(struct iio_dev indio_dev),
7b2c33b1	507	void (main)(struct iio_dev private_data, s64 time))
15744090 JC	508	{
	509	indio_dev->pollfunc = kzalloc(sizeof(*indio_dev->pollfunc), GFP_KERNEL);
	510	if (indio_dev->pollfunc == NULL)
	511	return -ENOMEM;
	512	indio_dev->pollfunc->poll_func_immediate = immediate;
	513	indio_dev->pollfunc->poll_func_main = main;
	514	indio_dev->pollfunc->private_data = indio_dev;
	515	return 0;
	516	}
	517	EXPORT_SYMBOL(iio_alloc_pollfunc);
c3db00cc JC	518
	519	int iio_triggered_ring_postenable(struct iio_dev *indio_dev)
	520	{
	521	return indio_dev->trig
	522	? iio_trigger_attach_poll_func(indio_dev->trig,
	523	indio_dev->pollfunc)
	524	: 0;
	525	}
	526	EXPORT_SYMBOL(iio_triggered_ring_postenable);
	527
	528	int iio_triggered_ring_predisable(struct iio_dev *indio_dev)
	529	{
	530	return indio_dev->trig
	531	? iio_trigger_dettach_poll_func(indio_dev->trig,
	532	indio_dev->pollfunc)
	533	: 0;
	534	}
	535	EXPORT_SYMBOL(iio_triggered_ring_predisable);