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- /* 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
- * @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 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);
- /* Get irq number */
- pf->irq = iio_trigger_get_irq(trig);
- if (pf->irq < 0)
- 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 < 0)
- goto out_free_irq;
- }
- 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(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
- * @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 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
- * @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 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) {
- 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) {
- iio_trigger_get(indio_dev->trig);
- if (indio_dev->modes & INDIO_EVENT_TRIGGERED)
- iio_trigger_attach_poll_func(indio_dev->trig,
- indio_dev->pollfunc_event);
- }
- 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);
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