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local.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 <[email protected]>
*/
#include "attr.h"
#include "iio-private.h"
#include "local.h"
#include "sort.h"
#include "deps/libini/ini.h"
#include <dirent.h>
#include <errno.h>
#include <iio/iio-backend.h>
#include <iio/iio-debug.h>
#include <iio/iio-lock.h>
#include <limits.h>
#include <poll.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <sys/eventfd.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>
#include <sys/utsname.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#define NB_BLOCKS 4
#define IIO_GET_EVENT_FD_IOCTL _IOR('i', 0x90, int)
#define IIO_BUFFER_GET_FD_IOCTL _IOWR('i', 0x91, int)
/* Forward declarations */
static ssize_t local_write_dev_attr(const struct iio_device *dev,
unsigned int buf_id, const char *attr,
const char *src, size_t len,
enum iio_attr_type type);
static struct iio_context *
local_create_context(const struct iio_context_params *params, const char *args);
static int local_context_scan(const struct iio_context_params *params,
struct iio_scan *ctx, const char *args);
struct iio_context_pdata {
struct iio_mutex *lock;
};
struct iio_device_pdata {
int fd;
};
struct iio_event_stream_pdata {
const struct iio_device *dev;
int fd, cancel_fd;
};
struct iio_channel_pdata {
char *enable_fn;
struct iio_attr_list protected;
};
static const char * const device_attrs_denylist[] = {
"dev",
"uevent",
};
static const char * const buffer_attrs_reserved[] = {
"length",
"enable",
"watermark",
};
int ioctl_nointr(int fd, unsigned long request, void *data)
{
int ret;
do {
ret = ioctl(fd, request, data);
} while (ret == -1 && errno == EINTR);
if (ret == -1)
ret = -errno;
return ret;
}
static void local_free_channel_pdata(struct iio_channel *chn)
{
if (chn->pdata) {
free(chn->pdata->enable_fn);
free(chn->pdata);
}
}
static void local_free_pdata(struct iio_device *device)
{
unsigned int i;
for (i = 0; i < device->nb_channels; i++)
local_free_channel_pdata(device->channels[i]);
free(device->pdata);
}
static void local_shutdown(struct iio_context *ctx)
{
/* Free the backend data stored in every device structure */
unsigned int i;
for (i = 0; i < iio_context_get_devices_count(ctx); i++) {
struct iio_device *dev = iio_context_get_device(ctx, i);
if (dev->pdata && dev->pdata->fd >= 0)
close(dev->pdata->fd);
local_free_pdata(dev);
}
if (ctx->pdata && ctx->pdata->lock)
iio_mutex_destroy(ctx->pdata->lock);
}
/** Shrinks the first nb characters of a string
* e.g. strcut("foobar", 4) replaces the content with "ar". */
static void strcut(char *str, int nb)
{
char *ptr = str + nb;
while (*ptr)
*str++ = *ptr++;
*str = 0;
}
static int set_channel_name(struct iio_channel *chn)
{
struct iio_channel_pdata *pdata = chn->pdata;
size_t prefix_len = 0;
const char *attr0;
const char *ptr;
unsigned int i;
if (chn->attrlist.num + pdata->protected.num < 2)
return 0;
if (chn->attrlist.num)
attr0 = ptr = chn->attrlist.attrs[0].name;
else
attr0 = ptr = pdata->protected.attrs[0].name;
while (true) {
bool can_fix = true;
size_t len;
ptr = strchr(ptr, '_');
if (!ptr)
break;
len = ptr - attr0 + 1;
for (i = 1; can_fix && i < chn->attrlist.num; i++)
can_fix = !strncmp(attr0, chn->attrlist.attrs[i].name, len);
for (i = !chn->attrlist.num;
can_fix && i < pdata->protected.num; i++) {
can_fix = !strncmp(attr0,
pdata->protected.attrs[i].name, len);
}
if (!can_fix)
break;
prefix_len = len;
ptr = ptr + 1;
}
if (prefix_len) {
char *name;
name = malloc(prefix_len);
if (!name)
return -ENOMEM;
iio_strlcpy(name, attr0, prefix_len);
chn->name = name;
chn_dbg(chn, "Setting name of channel %s to %s\n", chn->id, name);
/* Shrink the attribute name */
for (i = 0; i < chn->attrlist.num; i++)
strcut((char *) chn->attrlist.attrs[i].name, prefix_len);
for (i = 0; i < pdata->protected.num; i++)
strcut((char *) pdata->protected.attrs[i].name, prefix_len);
}
return 0;
}
/*
* Used to generate the timeout parameter for operations like poll. Returns the
* number of ms until it is timeout_rel ms after the time specified in start. If
* timeout_rel is 0 returns -1 to indicate no timeout.
*
* The timeout that is specified for IIO operations is the maximum time a buffer
* push() or refill() operation should take before returning. poll() is used to
* wait for either data activity or for the timeout to elapse. poll() might get
* interrupted in which case it is called again or the read()/write() operation
* might not complete the full buffer size in one call in which case we go back
* to poll() again as well. Passing the same timeout as before would increase
* the total timeout and if repeated interruptions occur (e.g. by a timer
* signal) the operation might never time out or with significant delay. Hence
* before each poll() invocation the timeout is recalculated relative to the
* start of refill() or push() operation.
*/
static int get_rel_timeout_ms(struct timespec *start, unsigned int timeout_rel)
{
struct timespec now;
int diff_ms;
if (timeout_rel == 0) /* No timeout */
return -1;
clock_gettime(CLOCK_MONOTONIC, &now);
diff_ms = (now.tv_sec - start->tv_sec) * 1000;
diff_ms += (now.tv_nsec - start->tv_nsec) / 1000000;
if (diff_ms >= (int) timeout_rel) /* Expired */
return 0;
if (diff_ms > 0) /* Should never be false, but lets be safe */
timeout_rel -= diff_ms;
if (timeout_rel > INT_MAX)
return INT_MAX;
return (int) timeout_rel;
}
int buffer_check_ready(struct iio_buffer_pdata *pdata, int fd,
short events, struct timespec *start)
{
struct pollfd pollfd[2] = {
{
.fd = fd,
.events = events,
}, {
.fd = pdata->cancel_fd,
.events = POLLIN,
}
};
unsigned int rw_timeout_ms = pdata->dev->ctx->params.timeout_ms;
int timeout_rel, ret;
do {
if (start)
timeout_rel = get_rel_timeout_ms(start, rw_timeout_ms);
else
timeout_rel = 0; /* non-blocking */
ret = poll(pollfd, 2, timeout_rel);
} while (ret == -1 && errno == EINTR);
if ((pollfd[1].revents & POLLIN))
return -EBADF;
if (ret < 0)
return -errno;
if (!ret)
return start ? -ETIMEDOUT : -EBUSY;
if (pollfd[0].revents & POLLNVAL)
return -EBADF;
if (!(pollfd[0].revents & events))
return -EIO;
return 0;
}
static int
local_set_buffer_size(const struct iio_buffer_pdata *pdata, size_t nb_samples)
{
char buf[32];
ssize_t ret;
iio_snprintf(buf, sizeof(buf), "%zu", nb_samples);
ret = local_write_dev_attr(pdata->dev, pdata->idx, "length",
buf, strlen(buf) + 1, IIO_ATTR_TYPE_BUFFER);
if (ret < 0)
return (int) ret;
return 0;
}
static int
local_set_watermark(const struct iio_buffer_pdata *pdata, size_t nb_samples)
{
char buf[32];
ssize_t ret;
iio_snprintf(buf, sizeof(buf), "%zu", nb_samples);
ret = local_write_dev_attr(pdata->dev, pdata->idx, "watermark",
buf, strlen(buf) + 1, IIO_ATTR_TYPE_BUFFER);
if (ret < 0 && ret != -ENOENT && ret != -EACCES)
return (int) ret;
return 0;
}
static int local_do_enable_buffer(struct iio_buffer_pdata *pdata, bool enable)
{
int ret;
ret = (int) local_write_dev_attr(pdata->dev, pdata->idx, "enable",
enable ? "1" : "0",
2, IIO_ATTR_TYPE_BUFFER);
if (ret < 0)
return ret;
return 0;
}
static int local_enable_buffer(struct iio_buffer_pdata *pdata,
size_t nb_samples, bool enable, bool cyclic)
{
int ret;
if ((pdata->dmabuf_supported | pdata->mmap_supported) != !nb_samples)
return -EINVAL;
if (nb_samples) {
ret = local_set_buffer_size(pdata, nb_samples);
if (ret)
return ret;
ret = local_set_watermark(pdata, nb_samples);
if (ret)
return ret;
}
return local_do_enable_buffer(pdata, true);
}
static ssize_t local_readbuf(struct iio_buffer_pdata *buffer,
void *dst, size_t len)
{
uintptr_t ptr = (uintptr_t) dst;
struct timespec start;
int fd = buffer->fd;
ssize_t readsize;
ssize_t ret;
if (fd == -1)
return -EBADF;
if (len == 0)
return 0;
clock_gettime(CLOCK_MONOTONIC, &start);
while (len > 0) {
ret = buffer_check_ready(buffer, fd, POLLIN, &start);
if (ret < 0)
break;
do {
ret = read(fd, (void *) ptr, len);
} while (ret == -1 && errno == EINTR);
if (ret == -1) {
if (errno == EAGAIN)
continue;
ret = -errno;
break;
} else if (ret == 0) {
ret = -EIO;
break;
}
ptr += ret;
len -= ret;
}
readsize = (ssize_t)(ptr - (uintptr_t) dst);
if ((ret > 0 || ret == -EAGAIN) && (readsize > 0))
return readsize;
else
return ret;
}
static ssize_t
local_writebuf(struct iio_buffer_pdata *buffer, const void *src, size_t len)
{
uintptr_t ptr = (uintptr_t) src;
struct timespec start;
int fd = buffer->fd;
ssize_t writtensize;
ssize_t ret;
if (fd == -1)
return -EBADF;
if (len == 0)
return 0;
clock_gettime(CLOCK_MONOTONIC, &start);
while (len > 0) {
ret = buffer_check_ready(buffer, fd, POLLOUT, &start);
if (ret < 0)
break;
do {
ret = write(fd, (void *) ptr, len);
} while (ret == -1 && errno == EINTR);
if (ret == -1) {
if (errno == EAGAIN)
continue;
ret = -errno;
break;
} else if (ret == 0) {
ret = -EIO;
break;
}
ptr += ret;
len -= ret;
}
writtensize = (ssize_t)(ptr - (uintptr_t) src);
if ((ret > 0 || ret == -EAGAIN) && (writtensize > 0))
return writtensize;
else
return ret;
}
static ssize_t local_do_read_dev_attr(const char *id, unsigned int buf_id,
const char *attr, char *dst, size_t len,
enum iio_attr_type type)
{
FILE *f;
char buf[1024];
ssize_t ret;
if (buf_id > 0)
return -ENOSYS;
switch (type) {
case IIO_ATTR_TYPE_DEVICE:
case IIO_ATTR_TYPE_CHANNEL:
if (WITH_HWMON && id[0] == 'h') {
iio_snprintf(buf, sizeof(buf), "/sys/class/hwmon/%s/%s",
id, attr);
} else {
iio_snprintf(buf, sizeof(buf), "/sys/bus/iio/devices/%s/%s",
id, attr);
}
break;
case IIO_ATTR_TYPE_DEBUG:
iio_snprintf(buf, sizeof(buf), "/sys/kernel/debug/iio/%s/%s",
id, attr);
break;
case IIO_ATTR_TYPE_BUFFER:
if (buf_id > 0) {
iio_snprintf(buf, sizeof(buf),
"/sys/bus/iio/devices/%s/buffer%u/%s",
id, buf_id, attr);
} else {
iio_snprintf(buf, sizeof(buf),
"/sys/bus/iio/devices/%s/buffer/%s",
id, attr);
}
break;
default:
return -EINVAL;
}
f = fopen(buf, "re");
if (!f)
return -errno;
ret = fread(dst, 1, len, f);
/* if we didn't read the entire file, fail */
if (!feof(f))
ret = -EFBIG;
if (ret > 0)
dst[ret - 1] = '\0';
else
dst[0] = '\0';
fflush(f);
if (ferror(f))
ret = -errno;
fclose(f);
return ret;
}
static ssize_t local_read_dev_attr(const struct iio_device *dev,
unsigned int buf_id, const char *attr,
char *dst, size_t len,
enum iio_attr_type type)
{
const char *id = iio_device_get_id(dev);
return local_do_read_dev_attr(id, buf_id, attr, dst, len, type);
}
static ssize_t local_write_dev_attr(const struct iio_device *dev,
unsigned int buf_id, const char *attr,
const char *src, size_t len,
enum iio_attr_type type)
{
FILE *f;
char buf[1024];
ssize_t ret;
if (buf_id > 0)
return -ENOSYS;
switch (type) {
case IIO_ATTR_TYPE_DEVICE:
case IIO_ATTR_TYPE_CHANNEL:
if (WITH_HWMON && iio_device_is_hwmon(dev)) {
iio_snprintf(buf, sizeof(buf), "/sys/class/hwmon/%s/%s",
dev->id, attr);
} else {
iio_snprintf(buf, sizeof(buf), "/sys/bus/iio/devices/%s/%s",
dev->id, attr);
}
break;
case IIO_ATTR_TYPE_DEBUG:
iio_snprintf(buf, sizeof(buf), "/sys/kernel/debug/iio/%s/%s",
dev->id, attr);
break;
case IIO_ATTR_TYPE_BUFFER:
if (buf_id > 0) {
iio_snprintf(buf, sizeof(buf),
"/sys/bus/iio/devices/%s/buffer%u/%s",
dev->id, buf_id, attr);
} else {
iio_snprintf(buf, sizeof(buf),
"/sys/bus/iio/devices/%s/buffer/%s",
dev->id, attr);
}
break;
default:
return -EINVAL;
}
f = fopen(buf, "we");
if (!f)
return -errno;
ret = fwrite(src, 1, len, f);
fflush(f);
if (ferror(f))
ret = -errno;
fclose(f);
return ret ? ret : -EIO;
}
static int channel_write_state(const struct iio_channel *chn,
unsigned int idx, bool en)
{
enum iio_attr_type type = idx ? IIO_ATTR_TYPE_BUFFER : IIO_ATTR_TYPE_DEVICE;
ssize_t ret;
if (!chn->pdata->enable_fn) {
chn_err(chn, "Libiio bug: No \"en\" attribute parsed\n");
return -EINVAL;
}
ret = local_write_dev_attr(chn->dev, idx, chn->pdata->enable_fn,
en ? "1" : "0", 2, type);
if (ret < 0)
return (int) ret;
else
return 0;
}
static int channel_read_state(const struct iio_channel *chn, unsigned int idx)
{
enum iio_attr_type type = idx ? IIO_ATTR_TYPE_BUFFER : IIO_ATTR_TYPE_DEVICE;
char buf[8];
int err;
err = local_read_dev_attr(chn->dev, idx, chn->pdata->enable_fn,
buf, sizeof(buf), type);
if (err < 0)
return err;
return buf[0] == '1';
}
static const struct iio_device * local_get_trigger(const struct iio_device *dev)
{
const struct iio_device *cur;
char buf[1024];
unsigned int i;
ssize_t nb;
nb = local_read_dev_attr(dev, 0, "trigger/current_trigger",
buf, sizeof(buf), IIO_ATTR_TYPE_DEVICE);
if (nb < 0)
return iio_ptr(nb);
if (buf[0] == '\0')
return iio_ptr(-ENODEV);
nb = iio_context_get_devices_count(dev->ctx);
for (i = 0; i < (size_t) nb; i++) {
cur = iio_context_get_device(dev->ctx, i);
if (cur->name && !strcmp(cur->name, buf))
return cur;
}
return iio_ptr(-ENXIO);
}
static int local_set_trigger(const struct iio_device *dev,
const struct iio_device *trigger)
{
ssize_t nb;
const char *value = trigger ? trigger->name : "";
nb = local_write_dev_attr(dev, 0, "trigger/current_trigger", value,
strlen(value) + 1, IIO_ATTR_TYPE_DEVICE);
if (nb < 0)
return (int) nb;
else
return 0;
}
static bool is_channel(const struct iio_device *dev, const char *attr, bool strict)
{
char *ptr = NULL;
if (WITH_HWMON && iio_device_is_hwmon(dev))
return iio_channel_is_hwmon(attr);
if (!strncmp(attr, "in_timestamp_", sizeof("in_timestamp_") - 1))
return true;
if (!strncmp(attr, "in_", 3))
ptr = strchr(attr + 3, '_');
else if (!strncmp(attr, "out_", 4))
ptr = strchr(attr + 4, '_');
if (!ptr)
return false;
if (!strict)
return true;
if (*(ptr - 1) >= '0' && *(ptr - 1) <= '9')
return true;
if (find_channel_modifier(ptr + 1, NULL) != IIO_NO_MOD)
return true;
return false;
}
static char * get_channel_id(struct iio_device *dev, const char *attr)
{
char *res, *ptr = strchr(attr, '_');
size_t len;
if (!WITH_HWMON || !iio_device_is_hwmon(dev)) {
attr = ptr + 1;
ptr = strchr(attr, '_');
if (find_channel_modifier(ptr + 1, &len) != IIO_NO_MOD)
ptr += len + 1;
} else if (!ptr) {
/*
* Attribute is 'pwmX' without underscore: the attribute name
* is our channel ID.
*/
return iio_strdup(attr);
}
res = malloc(ptr - attr + 1);
if (!res)
return NULL;
memcpy(res, attr, ptr - attr);
res[ptr - attr] = 0;
return res;
}
static const char *
get_short_attr_name(struct iio_channel *chn, const char *attr)
{
char *ptr = strchr(attr, '_');
size_t len;
if (WITH_HWMON && iio_device_is_hwmon(chn->dev)) {
/*
* PWM hwmon devices can have an attribute named directly after
* the channel's ID; in that particular case we don't need to
* strip the prefix.
*/
return ptr ? ptr + 1 : attr;
}
ptr = strchr(ptr + 1, '_') + 1;
if (find_channel_modifier(ptr, &len) != IIO_NO_MOD)
ptr += len + 1;
if (chn->name) {
len = strlen(chn->name);
if (strncmp(chn->name, ptr, len) == 0 && ptr[len] == '_')
ptr += len + 1;
}
return ptr;
}
static int add_attr_to_device(struct iio_device *dev, const char *attr)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(device_attrs_denylist); i++)
if (!strcmp(device_attrs_denylist[i], attr))
return 0;
if (!strcmp(attr, "name") || !strcmp(attr, "label"))
return 0;
return iio_device_add_attr(dev, attr, IIO_ATTR_TYPE_DEVICE);
}
static int handle_protected_scan_element_attr(struct iio_channel *chn,
const char *name, const char *path)
{
struct iio_device *dev = chn->dev;
char buf[1024];
int ret;
if (!strcmp(name, "index")) {
ret = local_read_dev_attr(dev, 0, path, buf, sizeof(buf),
IIO_ATTR_TYPE_DEVICE);
if (ret > 0) {
char *end;
long long value;
errno = 0;
value = strtoll(buf, &end, 0);
if (end == buf || value < 0 || errno == ERANGE)
return -EINVAL;
chn->index = (long) value;
}
} else if (!strcmp(name, "type")) {
ret = local_read_dev_attr(dev, 0, path, buf, sizeof(buf),
IIO_ATTR_TYPE_DEVICE);
if (ret > 0) {
char endian, sign;
if (strchr(buf, 'X')) {
iio_sscanf(buf, "%ce:%c%u/%uX%u>>%u",
#ifdef _MSC_BUILD
&endian, sizeof(endian),
&sign, sizeof(sign),
#else
&endian, &sign,
#endif
&chn->format.bits, &chn->format.length,
&chn->format.repeat, &chn->format.shift);
} else {
chn->format.repeat = 1;
iio_sscanf(buf, "%ce:%c%u/%u>>%u",
#ifdef _MSC_BUILD
&endian, sizeof(endian),
&sign, sizeof(sign),
#else
&endian, &sign,
#endif
&chn->format.bits, &chn->format.length,
&chn->format.shift);
}
chn->format.is_signed = (sign == 's' || sign == 'S');
chn->format.is_fully_defined =
(sign == 'S' || sign == 'U'||
chn->format.bits == chn->format.length);
chn->format.is_be = endian == 'b';
}
} else if (!strcmp(name, "en")) {
if (chn->pdata->enable_fn) {
chn_err(chn, "Libiio bug: \"en\" attribute already "
"parsed for channel %s!\n", chn->id);
return -EINVAL;
}
chn->pdata->enable_fn = iio_strdup(path);
if (!chn->pdata->enable_fn)
return -ENOMEM;
} else {
return -EINVAL;
}
return 0;
}
static int handle_scan_elements(struct iio_channel *chn)
{
struct iio_channel_pdata *pdata = chn->pdata;
unsigned int i;
for (i = 0; i < pdata->protected.num; i++) {
int ret = handle_protected_scan_element_attr(chn,
pdata->protected.attrs[i].name,
pdata->protected.attrs[i].filename);
if (ret < 0)
return ret;
}
return 0;
}
static void free_protected_attrs(struct iio_channel *chn)
{
struct iio_channel_pdata *pdata = chn->pdata;
iio_free_attrs(&pdata->protected);
}
static int add_attr_to_channel(struct iio_channel *chn,
const char *name, const char *path,
bool is_scan_element)
{
struct iio_channel_pdata *pdata = chn->pdata;
union iio_pointer p = { .chn = chn, };
struct iio_attr_list *attrs;
int ret;
size_t lbl_len = strlen("_label");
char label[512];
const char *dev_id;
if (strlen(name) >= lbl_len &&
!strcmp(name + strlen(name) - lbl_len, "_label")) {
dev_id = iio_device_get_id(iio_channel_get_device(chn));
ret = local_do_read_dev_attr(dev_id, 0, name,
label, sizeof(label), IIO_ATTR_TYPE_CHANNEL);
if (ret > 0)
chn->label = iio_strdup(label);
else
chn_perror(chn, ret, "Unable to read channel label");
return 0;
}
name = get_short_attr_name(chn, name);
attrs = is_scan_element ? &pdata->protected : &chn->attrlist;
ret = iio_add_attr(p, attrs, name, path, IIO_ATTR_TYPE_CHANNEL);
if (ret)
return ret;
chn_dbg(chn, "Added%s attr \'%s\' to channel \'%s\'\n",
is_scan_element ? " protected" : "", name, chn->id);
return 0;
}
static int add_channel_to_device(struct iio_device *dev,
struct iio_channel *chn)
{
struct iio_channel **channels = realloc(dev->channels,
(dev->nb_channels + 1) * sizeof(struct iio_channel *));
if (!channels)
return -ENOMEM;
channels[dev->nb_channels++] = chn;
dev->channels = channels;
dev_dbg(dev, "Added %s channel \'%s\' to device \'%s\'\n",
chn->is_output ? "output" : "input", chn->id, dev->id);
return 0;
}
static struct iio_channel *create_channel(struct iio_device *dev,
char *id, const char *attr, const char *path,
bool is_scan_element)
{
struct iio_channel *chn;
int err = -ENOMEM;
chn = zalloc(sizeof(*chn));
if (!chn)
return iio_ptr(-ENOMEM);
chn->pdata = zalloc(sizeof(*chn->pdata));
if (!chn->pdata)
goto err_free_chn;
if (!WITH_HWMON || !iio_device_is_hwmon(dev)) {
if (!strncmp(attr, "out_", 4)) {
chn->is_output = true;
} else if (strncmp(attr, "in_", 3)) {
err = -EINVAL;
goto err_free_chn_pdata;
}
}
chn->dev = dev;
chn->id = id;
chn->is_scan_element = is_scan_element;
chn->index = -ENOENT;
err = add_attr_to_channel(chn, attr, path, is_scan_element);
if (err)
goto err_free_chn_pdata;
return chn;
err_free_chn_pdata:
free(chn->pdata->enable_fn);
free(chn->pdata);
err_free_chn:
free(chn);
return iio_ptr(err);
}
static int add_channel(struct iio_device *dev, const char *name,
const char *path, bool dir_is_scan_elements)
{
struct iio_channel *chn;
char *channel_id;
unsigned int i;
int ret;
channel_id = get_channel_id(dev, name);
if (!channel_id)
return -ENOMEM;
for (i = 0; i < dev->nb_channels; i++) {
chn = dev->channels[i];
if (!strcmp(chn->id, channel_id)
&& chn->is_output == (name[0] == 'o')) {
free(channel_id);
ret = add_attr_to_channel(chn, name, path,
dir_is_scan_elements);
chn->is_scan_element |= dir_is_scan_elements && !ret;
return ret;
}
}
chn = create_channel(dev, channel_id, name, path, dir_is_scan_elements);
ret = iio_err(chn);
if (ret) {
free(channel_id);
return ret;
}
iio_channel_init_finalize(chn);
ret = add_channel_to_device(dev, chn);
if (ret) {
local_free_channel_pdata(chn);
free_channel(chn);
}
return ret;
}
/*
* Possible return values:
* 0 = Attribute should not be moved to the channel
* 1 = Attribute should be moved to the channel and it is a shared attribute
* 2 = Attribute should be moved to the channel and it is a private attribute
*/
static unsigned int is_global_attr(struct iio_channel *chn, const char *attr)
{
unsigned int len;
char *ptr, *dashptr;
if (!chn->is_output && !strncmp(attr, "in_", 3))
attr += 3;
else if (chn->is_output && !strncmp(attr, "out_", 4))
attr += 4;
else
return 0;
ptr = strchr(attr, '_');
if (!ptr)
return 0;
len = ptr - attr;
// Check for matching global differential attr, like "voltage-voltage"
dashptr = strchr(attr, '-');
if (dashptr && dashptr > attr && dashptr < ptr) {
unsigned int len1 = dashptr - attr;
unsigned int len2 = ptr - dashptr - 1;
const char* iddashptr = strchr(chn->id, '-');
if (iddashptr && strlen(iddashptr + 1) > len2 &&
(unsigned int)(iddashptr - chn->id) > len1 &&
chn->id[len1] >= '0' && chn->id[len1] <= '9' &&