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ops.c
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ops.c
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// SPDX-License-Identifier: LGPL-2.1-or-later
/*
* libiio - Library for interfacing industrial I/O (IIO) devices
*
* Copyright (C) 2014 Analog Devices, Inc.
* Author: Paul Cercueil <paul.cercueil@analog.com>
*/
#include "ops.h"
#include "parser.h"
#include "thread-pool.h"
#include "../debug.h"
#include <errno.h>
#include <limits.h>
#include <pthread.h>
#include <poll.h>
#include <stdbool.h>
#include <string.h>
#include <sys/eventfd.h>
#include <time.h>
#include <fcntl.h>
#include <signal.h>
int yyparse(yyscan_t scanner);
struct DevEntry;
/* Corresponds to a thread reading from a device */
struct ThdEntry {
SLIST_ENTRY(ThdEntry) parser_list_entry;
SLIST_ENTRY(ThdEntry) dev_list_entry;
unsigned int nb, sample_size, samples_count;
ssize_t err;
int eventfd;
struct parser_pdata *pdata;
struct iio_device *dev;
struct DevEntry *entry;
uint32_t *mask;
bool active, is_writer, new_client, wait_for_open;
};
static void thd_entry_event_signal(struct ThdEntry *thd)
{
uint64_t e = 1;
int ret;
do {
ret = write(thd->eventfd, &e, sizeof(e));
} while (ret == -1 && errno == EINTR);
}
static int thd_entry_event_wait(struct ThdEntry *thd, pthread_mutex_t *mutex,
int fd_in)
{
struct pollfd pfd[3];
uint64_t e;
int ret;
pthread_mutex_unlock(mutex);
pfd[0].fd = thd->eventfd;
pfd[0].events = POLLIN;
pfd[1].fd = fd_in;
pfd[1].events = POLLRDHUP;
pfd[2].fd = thread_pool_get_poll_fd(thd->pdata->pool);
pfd[2].events = POLLIN;
do {
poll_nointr(pfd, 3);
if ((pfd[1].revents & POLLRDHUP) || (pfd[2].revents & POLLIN)) {
pthread_mutex_lock(mutex);
return -EPIPE;
}
do {
ret = read(thd->eventfd, &e, sizeof(e));
} while (ret == -1 && errno == EINTR);
} while (ret == -1 && errno == EAGAIN);
pthread_mutex_lock(mutex);
return 0;
}
/* Corresponds to an opened device */
struct DevEntry {
unsigned int ref_count;
struct iio_device *dev;
struct iio_buffer *buf;
unsigned int sample_size, nb_clients;
unsigned int samples_count;
bool update_mask;
bool cyclic;
bool closed;
bool cancelled;
/* Linked list of ThdEntry structures corresponding
* to all the threads who opened the device */
SLIST_HEAD(ThdHead, ThdEntry) thdlist_head;
pthread_mutex_t thdlist_lock;
pthread_cond_t rw_ready_cond;
uint32_t *mask;
size_t nb_words;
};
struct sample_cb_info {
struct parser_pdata *pdata;
unsigned int nb_bytes, cpt;
uint32_t *mask;
};
/* Protects iio_device_{set,get}_data() from concurrent access from multiple
* clients */
static pthread_mutex_t devlist_lock = PTHREAD_MUTEX_INITIALIZER;
static unsigned int get_channel_number(const struct iio_channel *chn)
{
const struct iio_device *dev = iio_channel_get_device(chn);
const struct iio_channel *other;
unsigned int i = 0;
for (i = 0; i < iio_device_get_channels_count(dev); i++) {
other = iio_device_get_channel(dev, i);
if (other == chn)
break;
}
return i;
}
static inline const char *dev_label_or_name_or_id(const struct iio_device *dev)
{
const char *name;
name = iio_device_get_label(dev);
if (name)
return name;
name = iio_device_get_name(dev);
if (name)
return name;
return iio_device_get_id(dev);
}
#if WITH_AIO
static ssize_t async_io(struct parser_pdata *pdata, void *buf, size_t len,
bool do_read)
{
ssize_t ret;
struct pollfd pfd[2];
unsigned int num_pfds;
struct iocb iocb;
struct iocb *ios[1];
struct io_event e[1];
ios[0] = &iocb;
if (do_read)
io_prep_pread(&iocb, pdata->fd_in, buf, len, 0);
else
io_prep_pwrite(&iocb, pdata->fd_out, buf, len, 0);
io_set_eventfd(&iocb, pdata->aio_eventfd);
pthread_mutex_lock(&pdata->aio_mutex);
ret = io_submit(pdata->aio_ctx, 1, ios);
if (ret != 1) {
pthread_mutex_unlock(&pdata->aio_mutex);
IIO_ERROR("Failed to submit IO operation: %zd\n", ret);
return -EIO;
}
pfd[0].fd = pdata->aio_eventfd;
pfd[0].events = POLLIN;
pfd[0].revents = 0;
pfd[1].fd = thread_pool_get_poll_fd(pdata->pool);
pfd[1].events = POLLIN;
pfd[1].revents = 0;
num_pfds = 2;
do {
poll_nointr(pfd, num_pfds);
if (pfd[0].revents & POLLIN) {
uint64_t event;
ret = read(pdata->aio_eventfd, &event, sizeof(event));
if (ret != sizeof(event)) {
IIO_ERROR("Failed to read from eventfd: %d\n", -errno);
ret = -EIO;
break;
}
ret = io_getevents(pdata->aio_ctx, 0, 1, e, NULL);
if (ret != 1) {
IIO_ERROR("Failed to read IO events: %zd\n", ret);
ret = -EIO;
break;
} else {
ret = (long)e[0].res;
}
} else if ((num_pfds > 1 && pfd[1].revents & POLLIN)) {
/* Got a STOP event to abort this whole session */
ret = io_cancel(pdata->aio_ctx, &iocb, e);
if (ret != -EINPROGRESS && ret != -EINVAL) {
IIO_ERROR("Failed to cancel IO transfer: %zd\n", ret);
ret = -EIO;
break;
}
/* It should not be long now until we get the cancellation event */
num_pfds = 1;
}
} while (!(pfd[0].revents & POLLIN));
pthread_mutex_unlock(&pdata->aio_mutex);
/* Got STOP event, treat it as EOF */
if (num_pfds == 1)
return 0;
return ret;
}
#define MAX_AIO_REQ_SIZE (1024 * 1024)
static ssize_t readfd_aio(struct parser_pdata *pdata, void *dest, size_t len)
{
if (len > MAX_AIO_REQ_SIZE)
len = MAX_AIO_REQ_SIZE;
return async_io(pdata, dest, len, true);
}
static ssize_t writefd_aio(struct parser_pdata *pdata, const void *dest,
size_t len)
{
if (len > MAX_AIO_REQ_SIZE)
len = MAX_AIO_REQ_SIZE;
return async_io(pdata, (void *)dest, len, false);
}
#endif /* WITH_AIO */
static ssize_t readfd_io(struct parser_pdata *pdata, void *dest, size_t len)
{
ssize_t ret;
struct pollfd pfd[2];
pfd[0].fd = pdata->fd_in;
pfd[0].events = POLLIN | POLLRDHUP;
pfd[0].revents = 0;
pfd[1].fd = thread_pool_get_poll_fd(pdata->pool);
pfd[1].events = POLLIN;
pfd[1].revents = 0;
do {
poll_nointr(pfd, 2);
/* Got STOP event, or client closed the socket: treat it as EOF */
if (pfd[1].revents & POLLIN || pfd[0].revents & POLLRDHUP)
return 0;
if (pfd[0].revents & POLLERR)
return -EIO;
if (!(pfd[0].revents & POLLIN))
continue;
do {
if (pdata->fd_in_is_socket)
ret = recv(pdata->fd_in, dest, len, MSG_NOSIGNAL);
else
ret = read(pdata->fd_in, dest, len);
} while (ret == -1 && errno == EINTR);
if (ret != -1 || errno != EAGAIN)
break;
} while (true);
if (ret == -1)
return -errno;
return ret;
}
static ssize_t writefd_io(struct parser_pdata *pdata, const void *src, size_t len)
{
ssize_t ret;
struct pollfd pfd[2];
pfd[0].fd = pdata->fd_out;
pfd[0].events = POLLOUT;
pfd[0].revents = 0;
pfd[1].fd = thread_pool_get_poll_fd(pdata->pool);
pfd[1].events = POLLIN;
pfd[1].revents = 0;
do {
poll_nointr(pfd, 2);
/* Got STOP event, or client closed the socket: treat it as EOF */
if (pfd[1].revents & POLLIN || pfd[0].revents & POLLHUP)
return 0;
if (pfd[0].revents & POLLERR)
return -EIO;
if (!(pfd[0].revents & POLLOUT))
continue;
do {
if (pdata->fd_out_is_socket)
ret = send(pdata->fd_out, src, len, MSG_NOSIGNAL);
else
ret = write(pdata->fd_out, src, len);
} while (ret == -1 && errno == EINTR);
if (ret != -1 || errno != EAGAIN)
break;
} while (true);
if (ret == -1)
return -errno;
return ret;
}
ssize_t write_all(struct parser_pdata *pdata, const void *src, size_t len)
{
uintptr_t ptr = (uintptr_t) src;
while (len) {
ssize_t ret = pdata->writefd(pdata, (void *) ptr, len);
if (ret < 0)
return ret;
if (!ret)
return -EPIPE;
ptr += ret;
len -= ret;
}
return ptr - (uintptr_t) src;
}
static ssize_t read_all(struct parser_pdata *pdata,
void *dst, size_t len)
{
uintptr_t ptr = (uintptr_t) dst;
while (len) {
ssize_t ret = pdata->readfd(pdata, (void *) ptr, len);
if (ret < 0)
return ret;
if (!ret)
return -EPIPE;
ptr += ret;
len -= ret;
}
return ptr - (uintptr_t) dst;
}
static void print_value(struct parser_pdata *pdata, long value)
{
if (pdata->verbose && value < 0) {
char buf[1024];
iio_strerror(-value, buf, sizeof(buf));
output(pdata, "ERROR: ");
output(pdata, buf);
output(pdata, "\n");
} else {
char buf[128];
snprintf(buf, sizeof(buf), "%li\n", value);
output(pdata, buf);
}
}
static ssize_t send_sample(const struct iio_channel *chn,
void *src, size_t length, void *d)
{
unsigned int number = get_channel_number(chn);
struct sample_cb_info *info = d;
if (iio_channel_get_index(chn) < 0 || !TEST_BIT(info->mask, number))
return 0;
if (info->nb_bytes < length)
return 0;
if (info->cpt % length) {
unsigned int i, goal = length - info->cpt % length;
char zero = 0;
ssize_t ret;
for (i = 0; i < goal; i++) {
ret = info->pdata->writefd(info->pdata, &zero, 1);
if (ret < 0)
return ret;
}
info->cpt += goal;
}
info->cpt += length;
info->nb_bytes -= length;
return write_all(info->pdata, src, length);
}
static ssize_t receive_sample(const struct iio_channel *chn,
void *dst, size_t length, void *d)
{
unsigned int number = get_channel_number(chn);
struct sample_cb_info *info = d;
if (iio_channel_get_index(chn) < 0 || !TEST_BIT(info->mask, number))
return 0;
if (info->cpt == info->nb_bytes)
return 0;
/* Skip the padding if needed */
if (info->cpt % length) {
unsigned int i, goal = length - info->cpt % length;
char foo;
ssize_t ret;
for (i = 0; i < goal; i++) {
ret = info->pdata->readfd(info->pdata, &foo, 1);
if (ret < 0)
return ret;
}
info->cpt += goal;
}
info->cpt += length;
return read_all(info->pdata, dst, length);
}
static ssize_t send_data(struct DevEntry *dev, struct ThdEntry *thd, size_t len)
{
struct parser_pdata *pdata = thd->pdata;
bool demux = server_demux && dev->sample_size != thd->sample_size;
void *start;
if (demux)
len = (len / dev->sample_size) * thd->sample_size;
if (len > thd->nb)
len = thd->nb;
print_value(pdata, len);
if (thd->new_client) {
unsigned int i;
char buf[129], *ptr = buf;
uint32_t *mask = demux ? thd->mask : dev->mask;
ssize_t ret, length;
length = sizeof(buf);
/* Send the current mask */
for (i = dev->nb_words; i > 0 && ptr < buf + sizeof(buf);
i--, ptr += 8) {
snprintf(ptr, length, "%08x", mask[i - 1]);
length -= 8;
}
*ptr = '\n';
length--;
if (length < 0) {
IIO_ERROR("send_data: string length error\n");
return -ENOSPC;
}
ret = write_all(pdata, buf, ptr + 1 - buf);
if (ret < 0)
return ret;
thd->new_client = false;
}
if (!demux) {
/* Short path */
start = iio_buffer_start(dev->buf);
return write_all(pdata, start, len);
} else {
struct sample_cb_info info = {
.pdata = pdata,
.cpt = 0,
.nb_bytes = len,
.mask = thd->mask,
};
return iio_buffer_foreach_sample(dev->buf, send_sample, &info);
}
}
static ssize_t receive_data(struct DevEntry *dev, struct ThdEntry *thd)
{
struct parser_pdata *pdata = thd->pdata;
/* Inform that no error occurred, and that we'll start reading data */
if (thd->new_client) {
print_value(thd->pdata, 0);
thd->new_client = false;
}
if (dev->sample_size == thd->sample_size) {
/* Short path: Receive directly in the buffer */
size_t len = dev->sample_size * dev->samples_count;
if (thd->nb < len)
len = thd->nb;
return read_all(pdata, iio_buffer_start(dev->buf), len);
} else {
/* Long path: Mux the samples to the buffer */
struct sample_cb_info info = {
.pdata = pdata,
.cpt = 0,
.nb_bytes = thd->nb,
.mask = thd->mask,
};
return iio_buffer_foreach_sample(dev->buf,
receive_sample, &info);
}
}
static void dev_entry_put(struct DevEntry *entry)
{
bool free_entry = false;
pthread_mutex_lock(&entry->thdlist_lock);
entry->ref_count--;
if (entry->ref_count == 0)
free_entry = true;
pthread_mutex_unlock(&entry->thdlist_lock);
if (free_entry) {
pthread_mutex_destroy(&entry->thdlist_lock);
pthread_cond_destroy(&entry->rw_ready_cond);
free(entry->mask);
free(entry);
}
}
static void signal_thread(struct ThdEntry *thd, ssize_t ret)
{
thd->err = ret;
thd->nb = 0;
thd->active = false;
thd_entry_event_signal(thd);
}
static void rw_thd(struct thread_pool *pool, void *d)
{
struct DevEntry *entry = d;
struct ThdEntry *thd, *next_thd;
struct iio_device *dev = entry->dev;
unsigned int nb_words = entry->nb_words;
ssize_t ret = 0;
IIO_DEBUG("R/W thread started for device %s\n",
dev_label_or_name_or_id(dev));
while (true) {
bool has_readers = false, has_writers = false,
mask_updated = false;
unsigned int sample_size;
/* NOTE: this while loop must exit with thdlist_lock locked. */
pthread_mutex_lock(&entry->thdlist_lock);
if (SLIST_EMPTY(&entry->thdlist_head))
break;
if (entry->update_mask) {
unsigned int i;
unsigned int samples_count = 0;
memset(entry->mask, 0, nb_words * sizeof(*entry->mask));
SLIST_FOREACH(thd, &entry->thdlist_head, dev_list_entry) {
for (i = 0; i < nb_words; i++)
entry->mask[i] |= thd->mask[i];
if (thd->samples_count > samples_count)
samples_count = thd->samples_count;
}
if (entry->buf)
iio_buffer_destroy(entry->buf);
for (i = 0; i < iio_device_get_channels_count(dev); i++) {
struct iio_channel *chn = iio_device_get_channel(dev, i);
unsigned int number = get_channel_number(chn);
long index = iio_channel_get_index(chn);
if (index < 0)
continue;
if (TEST_BIT(entry->mask, number))
iio_channel_enable(chn);
else
iio_channel_disable(chn);
}
entry->buf = iio_device_create_buffer(dev,
samples_count, entry->cyclic);
if (!entry->buf) {
ret = -errno;
IIO_ERROR("Unable to create buffer\n");
break;
}
entry->cancelled = false;
/* Signal the threads that we opened the device */
SLIST_FOREACH(thd, &entry->thdlist_head, dev_list_entry) {
if (thd->wait_for_open) {
thd->wait_for_open = false;
signal_thread(thd, 0);
}
}
IIO_DEBUG("IIO device %s reopened with new mask:\n",
dev_label_or_name_or_id(dev));
for (i = 0; i < nb_words; i++)
IIO_DEBUG("Mask[%i] = 0x%08x\n", i, entry->mask[i]);
entry->update_mask = false;
entry->sample_size = iio_device_get_sample_size(dev);
entry->samples_count = samples_count;
mask_updated = true;
}
sample_size = entry->sample_size;
SLIST_FOREACH(thd, &entry->thdlist_head, dev_list_entry) {
thd->active = !thd->err && thd->nb >= sample_size;
if (mask_updated && thd->active)
signal_thread(thd, thd->nb);
if (thd->is_writer)
has_writers |= thd->active;
else
has_readers |= thd->active;
}
if (!has_readers && !has_writers) {
pthread_cond_wait(&entry->rw_ready_cond,
&entry->thdlist_lock);
}
pthread_mutex_unlock(&entry->thdlist_lock);
if (!has_readers && !has_writers)
continue;
if (has_readers) {
ssize_t nb_bytes;
ret = iio_buffer_refill(entry->buf);
pthread_mutex_lock(&entry->thdlist_lock);
/*
* When the last client disconnects the buffer is
* cancelled and iio_buffer_refill() returns an error. A
* new client might have connected before we got here
* though, in that case the rw thread has to stay active
* and a new buffer is created. If the list is still empty the loop
* will exit normally.
*/
if (entry->cancelled) {
pthread_mutex_unlock(&entry->thdlist_lock);
continue;
}
if (ret < 0) {
/* Reading from the device failed - signal the
* error to all connected clients. */
/* Don't use SLIST_FOREACH - see comment below */
for (thd = SLIST_FIRST(&entry->thdlist_head);
thd; thd = next_thd) {
next_thd = SLIST_NEXT(thd, dev_list_entry);
if (!thd->active || thd->is_writer)
continue;
signal_thread(thd, ret);
}
pthread_mutex_unlock(&entry->thdlist_lock);
continue;
}
nb_bytes = ret;
/* We don't use SLIST_FOREACH here. As soon as a thread is
* signaled, its "thd" structure might be freed;
* SLIST_FOREACH would then cause a segmentation fault, as it
* reads "thd" to get the address of the next element. */
for (thd = SLIST_FIRST(&entry->thdlist_head);
thd; thd = next_thd) {
next_thd = SLIST_NEXT(thd, dev_list_entry);
if (!thd->active || thd->is_writer)
continue;
ret = send_data(entry, thd, nb_bytes);
if (ret > 0)
thd->nb -= ret;
if (ret < 0 || thd->nb < sample_size)
signal_thread(thd, (ret < 0) ?
ret : (ssize_t) thd->nb);
}
pthread_mutex_unlock(&entry->thdlist_lock);
}
if (has_writers) {
ssize_t nb_bytes = 0;
pthread_mutex_lock(&entry->thdlist_lock);
/* Reset the size of the buffer to its maximum size.
*
* XXX(pcercuei): There is no way to perform this with
* the public libiio API. However, it probably does not
* matter; we only need to reset the size of the buffer
* if the buffer was used for receiving samples, and
* to date there is no IIO device that supports both
* receiving and sending samples.
*
* entry->buf->data_length = entry->buf->length;
*/
/* Same comment as above */
for (thd = SLIST_FIRST(&entry->thdlist_head);
thd; thd = next_thd) {
next_thd = SLIST_NEXT(thd, dev_list_entry);
if (!thd->active || !thd->is_writer)
continue;
ret = receive_data(entry, thd);
if (ret > 0) {
thd->nb -= ret;
if (ret > nb_bytes)
nb_bytes = ret;
}
if (ret < 0)
signal_thread(thd, ret);
}
ret = iio_buffer_push_partial(entry->buf,
nb_bytes / sample_size);
if (entry->cancelled) {
pthread_mutex_unlock(&entry->thdlist_lock);
continue;
}
/* Signal threads which completed their RW command */
for (thd = SLIST_FIRST(&entry->thdlist_head);
thd; thd = next_thd) {
next_thd = SLIST_NEXT(thd, dev_list_entry);
if (!thd->active || !thd->is_writer)
continue;
if (ret < 0)
signal_thread(thd, ret);
else if (thd->nb < sample_size)
signal_thread(thd, thd->nb);
}
pthread_mutex_unlock(&entry->thdlist_lock);
}
}
/* Signal all remaining threads */
for (thd = SLIST_FIRST(&entry->thdlist_head); thd; thd = next_thd) {
next_thd = SLIST_NEXT(thd, dev_list_entry);
SLIST_REMOVE(&entry->thdlist_head, thd, ThdEntry, dev_list_entry);
thd->wait_for_open = false;
signal_thread(thd, ret);
}
if (entry->buf) {
iio_buffer_destroy(entry->buf);
entry->buf = NULL;
}
entry->closed = true;
pthread_mutex_unlock(&entry->thdlist_lock);
pthread_mutex_lock(&devlist_lock);
/* It is possible that a new thread has already started, make sure to
* not overwrite it. */
if (iio_device_get_data(dev) == entry)
iio_device_set_data(dev, NULL);
pthread_mutex_unlock(&devlist_lock);
IIO_DEBUG("Stopping R/W thread for device %s\n",
dev_label_or_name_or_id(dev));
dev_entry_put(entry);
}
static struct ThdEntry *parser_lookup_thd_entry(struct parser_pdata *pdata,
struct iio_device *dev)
{
struct ThdEntry *t;
SLIST_FOREACH(t, &pdata->thdlist_head, parser_list_entry) {
if (t->dev == dev)
return t;
}
return NULL;
}
static ssize_t rw_buffer(struct parser_pdata *pdata,
struct iio_device *dev, unsigned int nb, bool is_write)
{
struct DevEntry *entry;
struct ThdEntry *thd;
ssize_t ret;
if (!dev)
return -ENODEV;
thd = parser_lookup_thd_entry(pdata, dev);
if (!thd)
return -EBADF;
entry = thd->entry;
if (nb < entry->sample_size)
return 0;
pthread_mutex_lock(&entry->thdlist_lock);
if (entry->closed) {
pthread_mutex_unlock(&entry->thdlist_lock);
return -EBADF;
}
if (thd->nb) {
pthread_mutex_unlock(&entry->thdlist_lock);
return -EBUSY;
}
thd->new_client = true;
thd->nb = nb;
thd->err = 0;
thd->is_writer = is_write;
thd->active = true;
pthread_cond_signal(&entry->rw_ready_cond);
IIO_DEBUG("Waiting for completion...\n");
while (thd->active) {
ret = thd_entry_event_wait(thd, &entry->thdlist_lock, pdata->fd_in);
if (ret)
break;
}
if (ret == 0)
ret = thd->err;
pthread_mutex_unlock(&entry->thdlist_lock);
if (ret > 0 && ret < (ssize_t) nb)
print_value(thd->pdata, 0);
IIO_DEBUG("Exiting rw_buffer with code %li\n", (long) ret);
if (ret < 0)
return ret;
else
return nb - ret;
}
static uint32_t *get_mask(const char *mask, size_t *len)
{
size_t nb = (*len + 7) / 8;
uint32_t *ptr, *words = calloc(nb, sizeof(*words));
if (!words)
return NULL;
ptr = words + nb;
while (*mask) {
char buf[9];
snprintf(buf, sizeof(buf), "%.*s", 8, mask);
sscanf(buf, "%08x", --ptr);
mask += 8;
IIO_DEBUG("Mask[%lu]: 0x%08x\n",
(unsigned long) (words - ptr) / 4, *ptr);
}
*len = nb;
return words;
}
static void free_thd_entry(struct ThdEntry *t)
{
close(t->eventfd);
free(t->mask);
free(t);
}
static void remove_thd_entry(struct ThdEntry *t)
{
struct DevEntry *entry = t->entry;
pthread_mutex_lock(&entry->thdlist_lock);
if (!entry->closed) {
entry->update_mask = true;
SLIST_REMOVE(&entry->thdlist_head, t, ThdEntry, dev_list_entry);
if (SLIST_EMPTY(&entry->thdlist_head) && entry->buf) {
entry->cancelled = true;
iio_buffer_cancel(entry->buf); /* Wakeup the rw thread */
}
pthread_cond_signal(&entry->rw_ready_cond);
}
pthread_mutex_unlock(&entry->thdlist_lock);
dev_entry_put(entry);
free_thd_entry(t);
}
static ssize_t get_dev_sample_size_mask(const struct iio_device *dev,
const uint32_t *mask, size_t words)
{
unsigned int i, len, number,
nb_channels = iio_device_get_channels_count(dev);
const struct iio_channel *prev = NULL;
const struct iio_channel *chn;
const struct iio_data_format *fmt;
long index;
ssize_t size = 0;
if (words != (nb_channels + 31) / 32)
return -EINVAL;
for (i = 0; i < nb_channels; i++) {
chn = iio_device_get_channel(dev, i);
number = get_channel_number(chn);
fmt = iio_channel_get_data_format(chn);
index = iio_channel_get_index(chn);
len = fmt->length / 8 * fmt->repeat;
if (index < 0)
break;
if (!TEST_BIT(mask, number))
continue;
if (prev && index == iio_channel_get_index(prev)) {
prev = chn;
continue;
}
if (size % len)
size += 2 * len - (size % len);
else
size += len;
prev = chn;
}
return size;
}
static int open_dev_helper(struct parser_pdata *pdata, struct iio_device *dev,
size_t samples_count, const char *mask, bool cyclic)
{
int ret = -ENOMEM;
struct DevEntry *entry;
struct ThdEntry *thd;
size_t len = strlen(mask);
uint32_t *words;
unsigned int nb_channels;
unsigned int cyclic_retry = 500;
if (!dev)
return -ENODEV;
nb_channels = iio_device_get_channels_count(dev);
if (len != ((nb_channels + 31) / 32) * 8)
return -EINVAL;
words = get_mask(mask, &len);
if (!words)
return -ENOMEM;
thd = zalloc(sizeof(*thd));
if (!thd)
goto err_free_words;
thd->wait_for_open = true;