- 根目录:
- 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_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);