/drivers/staging/iio/industrialio-trigger.c
https://bitbucket.org/slukk/jb-tsm-kernel-4.2 · C · 507 lines · 384 code · 62 blank · 61 comment · 45 complexity · 22f4317727a5729e18d03acbd1bb9a19 MD5 · raw file
- /* 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_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);
- }
- /**
- * 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;
- 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->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);
- /* 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;
- 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);
- return ret;
- }
- EXPORT_SYMBOL(iio_trigger_attach_poll_func);
- 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->set_trigger_state && no_other_users) {
- ret = trig->set_trigger_state(trig, false);
- if (ret)
- goto error_ret;
- }
- iio_trigger_put_irq(trig, pf->irq);
- free_irq(pf->irq, pf);
- 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);
- struct iio_poll_func
- *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p),
- irqreturn_t (*thread)(int irq, void *p),
- int type,
- void *private,
- 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->private_data = private;
- 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 *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->name);
- 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(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);
- }
- iio_get();
- }
- 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);
- 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_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);