Raspberries/mraa
Private
Public Access
2
0
Fork 0
Code Activity

iio: initial pass at getting channel information from scan_elements

Browse Source 
This commit creates a new structure inside each _iio device when used and can
then be used to understand the data being read after a trigger is run/executed

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Brendan Le Foll
2015-10-02 16:48:47 +01:00
parent b192e7a223
commit 2c97fd5953
5 changed files with 251 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

169
src/iio/iio.c
View File

@@ -26,8 +26,13 @@
#include "mraa_internal.h"
#include "dirent.h"
#include <string.h>
#include <poll.h>
#define IIO_SYSFS_DEVICE "/sys/bus/iio/devices/iio:device"
#define MAX_SIZE 128
#define IIO_DEVICE "iio:device"
#define IIO_SCAN_ELEM "scan_elements"
#define IIO_SLASH_DEV "/dev/"IIO_DEVICE
#define IIO_SYSFS_DEVICE "/sys/bus/iio/devices/"IIO_DEVICE
mraa_iio_context
mraa_iio_init(int device)
@@ -36,9 +41,107 @@ mraa_iio_init(int device)
return NULL;
}
mraa_iio_get_channel_data(&plat->iio_devices[device]);
return &plat->iio_devices[device];
}
int
mraa_iio_read_size(mraa_iio_context dev)
{
return dev->datasize;
}
mraa_iio_channel*
mraa_iio_get_channels(mraa_iio_context dev)
{
return dev->channels;
}
int
mraa_iio_get_channel_count(mraa_iio_context dev)
{
return dev->chan_num;
}
mraa_result_t
mraa_iio_get_channel_data(mraa_iio_context dev)
{
const struct dirent *ent;
DIR* dir;
int chan_num = 0;
char buf[MAX_SIZE];
char readbuf[32];
int fd;
int ret = 0;
int padint = 0;
int curr_bytes = 0;
char shortbuf, signchar;
memset(buf, 0, MAX_SIZE);
snprintf(buf, MAX_SIZE, IIO_SYSFS_DEVICE "%d/" IIO_SCAN_ELEM, dev->num);
dir = opendir(buf);
if (dir != NULL) {
while ((ent = readdir(dir)) != NULL) {
if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_en"), "_en") == 0) {
chan_num++;
}
}
}
dev->chan_num = chan_num;
mraa_iio_channel* chan;
dev->channels = calloc(chan_num, sizeof(mraa_iio_channel));
seekdir(dir, 0);
while ((ent = readdir(dir)) != NULL) {
if (strcmp(ent->d_name + strlen(ent->d_name) - strlen("_index"), "_index") == 0) {
snprintf(buf, MAX_SIZE, IIO_SYSFS_DEVICE "%d/" IIO_SCAN_ELEM "/%s", dev->num, ent->d_name);
fd = open(buf, O_RDONLY);
if (fd > 0) {
if (read(fd, readbuf, 2 * sizeof(char)) != 2) {
break;
}
chan_num = ((int) strtol(readbuf, NULL, 10));
chan = &dev->channels[chan_num];
chan->index = chan_num;
close(fd);
buf[(strlen(buf)-5)] = '\0';
char* str = strdup(buf);
snprintf(buf, MAX_SIZE, "%stype", str);
fd = open(buf, O_RDONLY);
if (fd > 0) {
read(fd, readbuf, 31 * sizeof(char));
ret = sscanf(readbuf, "%ce:%c%u/%u>>%u", &shortbuf,
&signchar, &chan->bits_used,
&padint, &chan->shift);
chan->bytes = padint / 8;
if (curr_bytes % chan->bytes == 0) {
chan->location = curr_bytes;
} else {
chan->location = curr_bytes - curr_bytes%chan->bytes + chan->bytes;
}
curr_bytes = chan->location + chan->bytes;
if (ret < 0) {
// probably should be 5?
return MRAA_IO_SETUP_FAILURE;
}
chan->signedd = (signchar == 's');
chan->lendian = (shortbuf == 'l');
if (chan->bits_used == 64) {
chan->mask = ~0;
} else {
chan->mask = (1 << chan->bits_used) - 1;
}
close(fd);
}
// todo - read scale & _en attributes
}
}
}
dev->datasize = curr_bytes;
return MRAA_SUCCESS;
}
const char*
mraa_iio_get_device_name(mraa_iio_context dev)
{
@@ -49,7 +152,7 @@ mraa_result_t
mraa_iio_read(mraa_iio_context dev, const char* attr_chan, float* data)
{
char buf[64];
snprintf(buf, 64, IIO_SYSFS_DEVICE, "%d/%s", dev->num, attr_chan);
snprintf(buf, 64, IIO_SYSFS_DEVICE "%d/%s", dev->num, attr_chan);
int fd = open(buf, O_RDONLY);
if (fd != -1) {
int len = read(fd, &buf, 64);
@@ -65,7 +168,69 @@ mraa_iio_write(mraa_iio_context dev, const char* attr_chan)
return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
}
static mraa_result_t
mraa_iio_wait_event(int fd, char* data)
{
struct pollfd pfd;
if (fd < 0) {
return MRAA_ERROR_INVALID_RESOURCE;
}
pfd.fd = fd;
pfd.events = POLLIN;
// Wait for it forever or until pthread_cancel
// poll is a cancelable point like sleep()
int x = poll(&pfd, 1, -1);
memset(data, 0, 100);
read(fd, data, 100);
return MRAA_SUCCESS;
}
static void*
mraa_iio_trigger_handler(void* arg)
{
mraa_iio_context dev = (mraa_iio_context) arg;
char data[MAX_SIZE*100];
for (;;) {
if (mraa_iio_wait_event(dev->fp, &data[0]) == MRAA_SUCCESS) {
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
dev->isr(&data);
pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
} else {
// we must have got an error code so die nicely
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
return NULL;
}
}
}
mraa_result_t
mraa_iio_trigger_buffer(mraa_iio_context dev, void (*fptr)(char* data), void* args)
{
char bu[MAX_SIZE];
if (dev->thread_id != 0) {
return MRAA_ERROR_NO_RESOURCES;
}
sprintf(bu, IIO_SLASH_DEV "%d", dev->num);
dev->fp = open(bu, O_RDONLY | O_NONBLOCK);
if (dev->fp == -1) {
return MRAA_ERROR_INVALID_RESOURCE;
}
dev->isr = fptr;
pthread_create(&dev->thread_id, NULL, mraa_iio_trigger_handler, (void*) dev);
return MRAA_SUCCESS;
}
#if 0
// does stop make any sense on iio devices?
mraa_result_t
mraa_iio_stop(mraa_iio_context dev)
{

2
src/mraa.c
View File

@@ -132,7 +132,6 @@ mraa_init()
if (plat != NULL)
plat->platform_type = platform_type;
#if defined(USBPLAT)
// This is a platform extender so create null base platform if one doesn't already exist
if (plat == NULL) {
plat = (mraa_board_t*) calloc(1, sizeof(mraa_board_t));
@@ -141,6 +140,7 @@ mraa_init()
plat->platform_name = "Null platform";
}
}
#if defined(USBPLAT)
// Now detect sub platform
if (plat != NULL) {
mraa_platform_t usb_platform_type = mraa_usb_platform_extender(plat);