mraa/src/iio/iio.c

/*
 * Author: Brendan Le Foll <brendan.le.foll@intel.com>
 * Copyright (c) 2015 Intel Corporation.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "iio.h"
#include "mraa_internal.h"
#include "dirent.h"
#include <string.h>

#define IIO_SYSFS_DEVICE "/sys/bus/iio/devices/iio:device"

mraa_iio_context
mraa_iio_init(int device)
{
    if (device > plat->iio_device_count) {
        return NULL;
    }

    mraa_iio_context dev = &plat->iio_devices[device];

    char* buf;
    char sep[] = "_";
    char* splitbuf;
    DIR* dir;
    struct dirent *ent;
    if ((dir = opendir (IIO_SYSFS_DEVICE "0/")) != NULL) {
        while ((ent = readdir (dir)) != NULL) {
            if (strlen(ent->d_name) > 3) {
                if (strncmp(ent->d_name, "in_", 3) == 0) {
                    dev->attrnum++;
                    buf = strndup(&ent->d_name[3], 64);
                    splitbuf = strsep(&buf, sep);
                    if (buf == NULL) {
                        return NULL;
                    }
                    int num = atoi(&splitbuf[strlen(splitbuf)-1]);
                    if (dev->channum < num) {
                        dev->channum = num;
                    }
                    free(splitbuf);
                }
                else if (strncmp(ent->d_name, "out_", 4) == 0) {
                    dev->attrnum++;
                }
            }
        }
        closedir (dir);
    } else {
        return NULL;
    }

    return dev;
}

// -1 is the device 'channel'
int
mraa_iio_get_attr_count(mraa_iio_context dev, int channel)
{
    // search is 0 indexed
    return dev->attrnum + 1;
}

int
mraa_iio_get_channel_count(mraa_iio_context dev)
{
    // search is 0 indexed
    return dev->channum + 1;
}

const char*
mraa_iio_get_device_name(mraa_iio_context dev)
{
    return dev->name;
}

#if 0
mraa_result_t
mraa_iio_get_attr_data(mraa_iio_context dev, mraa_iio_channel* chan)
{
    return MRAA_FEATURE_NOT_IMPLEMENTED;
}
#endif

mraa_result_t
mraa_iio_read(mraa_iio_context dev, const char* attribute, float* data)
{
    char buf[64];
    snprintf(buf, 64, IIO_SYSFS_DEVICE, "%d/%s", dev->num, attribute);
    int fd = open(buf, O_RDONLY);
    if (fd != -1) {
        int len = read(fd, &buf, 64);
        *data = strtol(buf, NULL, 10);
        return MRAA_SUCCESS;
    }
    return MRAA_ERROR_UNSPECIFIED;
}

mraa_result_t
mraa_iio_write(mraa_iio_context dev, const char* attribute)
{
    return MRAA_ERROR_FEATURE_NOT_IMPLEMENTED;
}

mraa_result_t
mraa_iio_stop(mraa_iio_context dev)
{
    free(dev);
    return MRAA_SUCCESS;
}