root/drivers/iio/industrialio-trigger.c
// SPDX-License-Identifier: GPL-2.0-only
/* The industrial I/O core, trigger handling functions
 *
 * Copyright (c) 2008 Jonathan Cameron
 */

#include <linux/cleanup.h>
#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/iio-opaque.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);

/**
 * name_show() - retrieve useful identifying name
 * @dev:        device associated with the iio_trigger
 * @attr:       pointer to the device_attribute structure that is
 *              being processed
 * @buf:        buffer to print the name into
 *
 * Return: a negative number on failure or the number of written
 *         characters on success.
 */
static ssize_t name_show(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        struct iio_trigger *trig = to_iio_trigger(dev);

        return sysfs_emit(buf, "%s\n", trig->name);
}

static DEVICE_ATTR_RO(name);

static struct attribute *iio_trig_dev_attrs[] = {
        &dev_attr_name.attr,
        NULL,
};
ATTRIBUTE_GROUPS(iio_trig_dev);

static struct iio_trigger *__iio_trigger_find_by_name(const char *name);

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

        trig_info->id = ida_alloc(&iio_trigger_ida, 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%d", 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 */
        scoped_guard(mutex, &iio_trigger_list_lock) {
                if (__iio_trigger_find_by_name(trig_info->name)) {
                        pr_err("Duplicate trigger name '%s'\n", trig_info->name);
                        ret = -EEXIST;
                        goto error_device_del;
                }
                list_add_tail(&trig_info->list, &iio_trigger_list);
        }

        return 0;

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

void iio_trigger_unregister(struct iio_trigger *trig_info)
{
        scoped_guard(mutex, &iio_trigger_list_lock)
                list_del(&trig_info->list);

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

int iio_trigger_set_immutable(struct iio_dev *indio_dev, struct iio_trigger *trig)
{
        struct iio_dev_opaque *iio_dev_opaque;

        if (!indio_dev || !trig)
                return -EINVAL;

        iio_dev_opaque = to_iio_dev_opaque(indio_dev);
        guard(mutex)(&iio_dev_opaque->mlock);
        WARN_ON(iio_dev_opaque->trig_readonly);

        indio_dev->trig = iio_trigger_get(trig);
        iio_dev_opaque->trig_readonly = true;

        return 0;
}
EXPORT_SYMBOL(iio_trigger_set_immutable);

/* Search for trigger by name, assuming iio_trigger_list_lock held */
static struct iio_trigger *__iio_trigger_find_by_name(const char *name)
{
        struct iio_trigger *iter;

        list_for_each_entry(iter, &iio_trigger_list, list)
                if (!strcmp(iter->name, name))
                        return iter;

        return NULL;
}

static struct iio_trigger *iio_trigger_acquire_by_name(const char *name)
{
        struct iio_trigger *iter;

        guard(mutex)(&iio_trigger_list_lock);
        list_for_each_entry(iter, &iio_trigger_list, list)
                if (sysfs_streq(iter->name, name))
                        return iio_trigger_get(iter);

        return NULL;
}

static void iio_reenable_work_fn(struct work_struct *work)
{
        struct iio_trigger *trig = container_of(work, struct iio_trigger,
                                                reenable_work);

        /*
         * This 'might' occur after the trigger state is set to disabled -
         * in that case the driver should skip reenabling.
         */
        trig->ops->reenable(trig);
}

/*
 * In general, reenable callbacks may need to sleep and this path is
 * not performance sensitive, so just queue up a work item
 * to reneable the trigger for us.
 *
 * Races that can cause this.
 * 1) A handler occurs entirely in interrupt context so the counter
 *    the final decrement is still in this interrupt.
 * 2) The trigger has been removed, but one last interrupt gets through.
 *
 * For (1) we must call reenable, but not in atomic context.
 * For (2) it should be safe to call reenanble, if drivers never blindly
 * reenable after state is off.
 */
static void iio_trigger_notify_done_atomic(struct iio_trigger *trig)
{
        if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
            trig->ops->reenable)
                schedule_work(&trig->reenable_work);
}

/**
 * iio_trigger_poll() - Call the IRQ trigger handler of the consumers
 * @trig: trigger which occurred
 *
 * This function should only be called from a hard IRQ context.
 */
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_atomic(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);

/**
 * iio_trigger_poll_nested() - Call the threaded trigger handler of the
 * consumers
 * @trig: trigger which occurred
 *
 * This function should only be called from a kernel thread context.
 */
void iio_trigger_poll_nested(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_nested);

void iio_trigger_notify_done(struct iio_trigger *trig)
{
        if (atomic_dec_and_test(&trig->use_count) && trig->ops &&
            trig->ops->reenable)
                trig->ops->reenable(trig);
}
EXPORT_SYMBOL(iio_trigger_notify_done);

/* Trigger Consumer related functions */
static int iio_trigger_get_irq(struct iio_trigger *trig)
{
        int ret;

        scoped_guard(mutex, &trig->pool_lock) {
                ret = bitmap_find_free_region(trig->pool,
                                              CONFIG_IIO_CONSUMERS_PER_TRIGGER,
                                              ilog2(1));
                if (ret < 0)
                        return ret;
        }

        return ret + trig->subirq_base;
}

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

/* 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)
{
        struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(pf->indio_dev);
        bool notinuse =
                bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
        int ret = 0;

        /* Prevent the module from being removed whilst attached to a trigger */
        __module_get(iio_dev_opaque->driver_module);

        /* Get irq number */
        pf->irq = iio_trigger_get_irq(trig);
        if (pf->irq < 0) {
                pr_err("Could not find an available irq for trigger %s, CONFIG_IIO_CONSUMERS_PER_TRIGGER=%d limit might be exceeded\n",
                        trig->name, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
                goto out_put_module;
        }

        /* Request irq */
        ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
                                   pf->type, pf->name,
                                   pf);
        if (ret < 0)
                goto out_put_irq;

        /* Enable trigger in driver */
        if (trig->ops && trig->ops->set_trigger_state && notinuse) {
                ret = trig->ops->set_trigger_state(trig, true);
                if (ret)
                        goto out_free_irq;
        }

        /*
         * Check if we just registered to our own trigger: we determine that
         * this is the case if the IIO device and the trigger device share the
         * same parent device.
         */
        if (!iio_validate_own_trigger(pf->indio_dev, trig))
                trig->attached_own_device = true;

        return ret;

out_free_irq:
        free_irq(pf->irq, pf);
out_put_irq:
        iio_trigger_put_irq(trig, pf->irq);
out_put_module:
        module_put(iio_dev_opaque->driver_module);
        return ret;
}

int iio_trigger_detach_poll_func(struct iio_trigger *trig,
                                 struct iio_poll_func *pf)
{
        struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(pf->indio_dev);
        bool no_other_users =
                bitmap_weight(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER) == 1;
        int ret = 0;

        if (trig->ops && trig->ops->set_trigger_state && no_other_users) {
                ret = trig->ops->set_trigger_state(trig, false);
                if (ret)
                        return ret;
        }
        if (pf->indio_dev->dev.parent == trig->dev.parent)
                trig->attached_own_device = false;
        iio_trigger_put_irq(trig, pf->irq);
        free_irq(pf->irq, pf);
        module_put(iio_dev_opaque->driver_module);
        pf->irq = 0;

        return ret;
}

irqreturn_t iio_pollfunc_store_time(int irq, void *p)
{
        struct iio_poll_func *pf = p;

        pf->timestamp = iio_get_time_ns(pf->indio_dev);
        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_obj(*pf);
        if (!pf)
                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);

/**
 * current_trigger_show() - trigger consumer sysfs query current trigger
 * @dev:        device associated with an industrial I/O device
 * @attr:       pointer to the device_attribute structure that
 *              is being processed
 * @buf:        buffer where the current trigger name will be printed into
 *
 * For trigger consumers the current_trigger interface allows the trigger
 * used by the device to be queried.
 *
 * Return: a negative number on failure, the number of characters written
 *         on success or 0 if no trigger is available
 */
static ssize_t current_trigger_show(struct device *dev,
                                    struct device_attribute *attr, char *buf)
{
        struct iio_dev *indio_dev = dev_to_iio_dev(dev);

        if (indio_dev->trig)
                return sysfs_emit(buf, "%s\n", indio_dev->trig->name);
        return 0;
}

/**
 * current_trigger_store() - trigger consumer sysfs set current trigger
 * @dev:        device associated with an industrial I/O device
 * @attr:       device attribute that is being processed
 * @buf:        string buffer that holds the name of the trigger
 * @len:        length of the trigger name held by buf
 *
 * 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.
 *
 * Return: negative error code on failure or length of the buffer
 *         on success
 */
static ssize_t current_trigger_store(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_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
        struct iio_trigger *oldtrig = indio_dev->trig;
        struct iio_trigger *trig;
        int ret;

        scoped_guard(mutex, &iio_dev_opaque->mlock) {
                if (iio_dev_opaque->currentmode == INDIO_BUFFER_TRIGGERED)
                        return -EBUSY;
                if (iio_dev_opaque->trig_readonly)
                        return -EPERM;
        }

        trig = iio_trigger_acquire_by_name(buf);
        if (oldtrig == trig) {
                ret = len;
                goto out_trigger_put;
        }

        if (trig && indio_dev->info->validate_trigger) {
                ret = indio_dev->info->validate_trigger(indio_dev, trig);
                if (ret)
                        goto out_trigger_put;
        }

        if (trig && trig->ops && trig->ops->validate_device) {
                ret = trig->ops->validate_device(trig, indio_dev);
                if (ret)
                        goto out_trigger_put;
        }

        indio_dev->trig = trig;

        if (oldtrig) {
                if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
                        iio_trigger_detach_poll_func(oldtrig,
                                                     indio_dev->pollfunc_event);
                iio_trigger_put(oldtrig);
        }
        if (indio_dev->trig) {
                if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
                        iio_trigger_attach_poll_func(indio_dev->trig,
                                                     indio_dev->pollfunc_event);
        }

        return len;

out_trigger_put:
        if (trig)
                iio_trigger_put(trig);
        return ret;
}

static DEVICE_ATTR_RW(current_trigger);

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 const 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 __printf(3, 0)
struct iio_trigger *viio_trigger_alloc(struct device *parent,
                                       struct module *this_mod,
                                       const char *fmt,
                                       va_list vargs)
{
        struct iio_trigger *trig;
        int i;

        trig = kzalloc_obj(*trig);
        if (!trig)
                return NULL;

        trig->dev.parent = parent;
        trig->dev.type = &iio_trig_type;
        trig->dev.bus = &iio_bus_type;
        device_initialize(&trig->dev);
        INIT_WORK(&trig->reenable_work, iio_reenable_work_fn);

        mutex_init(&trig->pool_lock);
        trig->subirq_base = irq_alloc_descs(-1, 0,
                                            CONFIG_IIO_CONSUMERS_PER_TRIGGER,
                                            0);
        if (trig->subirq_base < 0)
                goto free_trig;

        trig->name = kvasprintf(GFP_KERNEL, fmt, vargs);
        if (trig->name == NULL)
                goto free_descs;

        INIT_LIST_HEAD(&trig->list);

        trig->owner = this_mod;

        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);
        }

        return trig;

free_descs:
        irq_free_descs(trig->subirq_base, CONFIG_IIO_CONSUMERS_PER_TRIGGER);
free_trig:
        kfree(trig);
        return NULL;
}

/**
 * __iio_trigger_alloc - Allocate a trigger
 * @parent:             Device to allocate iio_trigger for
 * @this_mod:           module allocating the trigger
 * @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.
 * RETURNS:
 * Pointer to allocated iio_trigger on success, NULL on failure.
 */
struct iio_trigger *__iio_trigger_alloc(struct device *parent,
                                        struct module *this_mod,
                                        const char *fmt, ...)
{
        struct iio_trigger *trig;
        va_list vargs;

        va_start(vargs, fmt);
        trig = viio_trigger_alloc(parent, this_mod, 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);
}

/**
 * __devm_iio_trigger_alloc - Resource-managed iio_trigger_alloc()
 * Managed iio_trigger_alloc.  iio_trigger allocated with this function is
 * automatically freed on driver detach.
 * @parent:             Device to allocate iio_trigger for
 * @this_mod:           module allocating the trigger
 * @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.
 *
 *
 * RETURNS:
 * Pointer to allocated iio_trigger on success, NULL on failure.
 */
struct iio_trigger *__devm_iio_trigger_alloc(struct device *parent,
                                             struct module *this_mod,
                                             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(parent, this_mod, fmt, vargs);
        va_end(vargs);
        if (trig) {
                *ptr = trig;
                devres_add(parent, ptr);
        } else {
                devres_free(ptr);
        }

        return trig;
}
EXPORT_SYMBOL_GPL(__devm_iio_trigger_alloc);

static void devm_iio_trigger_unreg(void *trigger_info)
{
        iio_trigger_unregister(trigger_info);
}

/**
 * devm_iio_trigger_register - Resource-managed iio_trigger_register()
 * @dev:        device this trigger was allocated for
 * @trig_info:  trigger to register
 *
 * Managed iio_trigger_register().  The IIO trigger registered with this
 * function is automatically unregistered on driver detach. This function
 * calls iio_trigger_register() internally. Refer to that function for more
 * information.
 *
 * RETURNS:
 * 0 on success, negative error number on failure.
 */
int devm_iio_trigger_register(struct device *dev,
                              struct iio_trigger *trig_info)
{
        int ret;

        ret = iio_trigger_register(trig_info);
        if (ret)
                return ret;

        return devm_add_action_or_reset(dev, devm_iio_trigger_unreg, trig_info);
}
EXPORT_SYMBOL_GPL(devm_iio_trigger_register);

bool iio_trigger_using_own(struct iio_dev *indio_dev)
{
        return indio_dev->trig->attached_own_device;
}
EXPORT_SYMBOL(iio_trigger_using_own);

/**
 * iio_validate_own_trigger - Check if a trigger and IIO device belong to
 *  the same device
 * @idev: the IIO device to check
 * @trig: the IIO trigger to check
 *
 * This function can be used as the validate_trigger callback for triggers that
 * can only be attached to their own device.
 *
 * Return: 0 if both the trigger and the IIO device belong to the same
 * device, -EINVAL otherwise.
 */
int iio_validate_own_trigger(struct iio_dev *idev, struct iio_trigger *trig)
{
        if (idev->dev.parent != trig->dev.parent)
                return -EINVAL;
        return 0;
}
EXPORT_SYMBOL_GPL(iio_validate_own_trigger);

/**
 * iio_trigger_validate_own_device - Check if a trigger and IIO device belong to
 *  the same device
 * @trig: The IIO trigger to check
 * @indio_dev: the IIO device to check
 *
 * This function can be used as the validate_device callback for triggers that
 * can only be attached to their own device.
 *
 * Return: 0 if both the trigger and the IIO device belong to the same
 * device, -EINVAL otherwise.
 */
int iio_trigger_validate_own_device(struct iio_trigger *trig,
                                    struct iio_dev *indio_dev)
{
        if (indio_dev->dev.parent != trig->dev.parent)
                return -EINVAL;
        return 0;
}
EXPORT_SYMBOL(iio_trigger_validate_own_device);

int iio_device_register_trigger_consumer(struct iio_dev *indio_dev)
{
        return iio_device_register_sysfs_group(indio_dev,
                                               &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_device_suspend_triggering(struct iio_dev *indio_dev)
{
        struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);

        guard(mutex)(&iio_dev_opaque->mlock);

        if ((indio_dev->pollfunc) && (indio_dev->pollfunc->irq > 0))
                disable_irq(indio_dev->pollfunc->irq);

        return 0;
}
EXPORT_SYMBOL(iio_device_suspend_triggering);

int iio_device_resume_triggering(struct iio_dev *indio_dev)
{
        struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);

        guard(mutex)(&iio_dev_opaque->mlock);

        if ((indio_dev->pollfunc) && (indio_dev->pollfunc->irq > 0))
                enable_irq(indio_dev->pollfunc->irq);

        return 0;
}
EXPORT_SYMBOL(iio_device_resume_triggering);