C++ (Cpp) mraa_gpio_get_valfp Examples

Example #1

File: gpio.c Project: chenyiran/mraa

mraa_result_t
mraa_gpio_write(mraa_gpio_context dev, int value)
{
    if (dev == NULL)
        return MRAA_ERROR_INVALID_HANDLE;

    if (dev->mmap_write != NULL)
        return dev->mmap_write(dev,value);

    if (advance_func->gpio_write_pre != NULL) {
        mraa_result_t pre_ret = (advance_func->gpio_write_pre(dev,value));
        if(pre_ret != MRAA_SUCCESS)
            return pre_ret;
    }

    if (dev->value_fp == -1) {
        if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
            return MRAA_ERROR_INVALID_RESOURCE;
        }
    }

    if (lseek(dev->value_fp, 0, SEEK_SET) == -1) {
        return MRAA_ERROR_INVALID_RESOURCE;
    }

    char bu[MAX_SIZE];
    int length = snprintf(bu, sizeof(bu), "%d", value);
    if (write(dev->value_fp, bu, length*sizeof(char)) == -1) {
        return MRAA_ERROR_INVALID_HANDLE;
    }

    if (advance_func->gpio_write_post != NULL)
        return advance_func->gpio_write_post(dev,value);
    return MRAA_SUCCESS;
}

Example #2

File: gpio.c Project: chenyiran/mraa

int
mraa_gpio_read(mraa_gpio_context dev)
{
    if (dev == NULL)
        return -1;

    if (dev->mmap_read != NULL)
        return dev->mmap_read(dev);

    if (dev->value_fp == -1) {
        if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
            syslog(LOG_ERR, "gpio: Failed to get value file pointer");
            return -1;
        }
    }
    else {
        // if value_fp is new this is pointless
        lseek(dev->value_fp, 0, SEEK_SET);
    }
    char bu[2];
    if (read(dev->value_fp, bu, 2*sizeof(char)) != 2) {
        syslog(LOG_ERR, "gpio: Failed to read a sensible value from sysfs");
        return -1;
    }
    lseek(dev->value_fp, 0, SEEK_SET);

    return (int) strtol(bu, NULL, 10);
}

Example #3

File: gpio.c Project: fboudra/mraa

int
mraa_gpio_read(mraa_gpio_context dev)
{
    if (dev == NULL) {
        syslog(LOG_ERR, "gpio: read: context is invalid");
        return -1;
    }

    if (IS_FUNC_DEFINED(dev, gpio_read_replace))
        return dev->advance_func->gpio_read_replace(dev);

    if (dev->mmap_read != NULL)
        return dev->mmap_read(dev);

    if (dev->value_fp == -1) {
        if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
            return -1;
        }
    } else {
        // if value_fp is new this is pointless
        lseek(dev->value_fp, 0, SEEK_SET);
    }
    char bu[2];
    if (read(dev->value_fp, bu, 2 * sizeof(char)) != 2) {
        syslog(LOG_ERR, "gpio%i: read: Failed to read a sensible value from sysfs: %s", dev->pin, strerror(errno));
        return -1;
    }
    lseek(dev->value_fp, 0, SEEK_SET);

    return (int) strtol(bu, NULL, 10);
}

Example #4

File: gpio.c Project: fboudra/mraa

mraa_result_t
mraa_gpio_write(mraa_gpio_context dev, int value)
{
    if (dev == NULL) {
        syslog(LOG_ERR, "gpio: write: context is invalid");
        return MRAA_ERROR_INVALID_HANDLE;
    }

    if (dev->mmap_write != NULL)
        return dev->mmap_write(dev, value);

    if (IS_FUNC_DEFINED(dev, gpio_write_pre)) {
        mraa_result_t pre_ret = (dev->advance_func->gpio_write_pre(dev, value));
        if (pre_ret != MRAA_SUCCESS)
            return pre_ret;
    }

    if (IS_FUNC_DEFINED(dev, gpio_write_replace)) {
        return dev->advance_func->gpio_write_replace(dev, value);
    }

    if (dev->value_fp == -1) {
        if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
            return MRAA_ERROR_INVALID_RESOURCE;
        }
    }

    if (lseek(dev->value_fp, 0, SEEK_SET) == -1) {
        syslog(LOG_ERR, "gpio%i: write: Failed to lseek 'value': %s", dev->pin, strerror(errno));
          return MRAA_ERROR_UNSPECIFIED;
    }

    char bu[MAX_SIZE];
    int length = snprintf(bu, sizeof(bu), "%d", value);
    if (write(dev->value_fp, bu, length * sizeof(char)) == -1) {
        syslog(LOG_ERR, "gpio%i: write: Failed to write to 'value': %s", dev->pin, strerror(errno));
        return MRAA_ERROR_UNSPECIFIED;
    }

    if (IS_FUNC_DEFINED(dev, gpio_write_post))
        return dev->advance_func->gpio_write_post(dev, value);
    return MRAA_SUCCESS;
}