Function _audio_dev_write

components/drivers/audio/dev_audio.c:491–544

* @brief Write data into replay data queue and replay it * * @param[in] dev pointer to device * * @param[in] pos useless param * * @param[in] buffer a data buffer to be written into data queue * * @param[in] size buffer size * * @return the actually read size on successfully, otherwise 0 will be returned. * * @note This function will take mutex. */

 * @note This function will take mutex.
 */
static rt_ssize_t _audio_dev_write(struct rt_device *dev, rt_off_t pos, const void *buffer, rt_size_t size)
{

    struct rt_audio_device *audio;
    rt_uint8_t *ptr;
    rt_uint16_t block_size, remain_bytes, index = 0;

    RT_ASSERT(dev != RT_NULL);
    audio = (struct rt_audio_device *) dev;

    if (!(dev->open_flag & RT_DEVICE_OFLAG_WRONLY) || (audio->replay == RT_NULL))
        return 0;

    /* push a new frame to replay data queue */
    ptr = (rt_uint8_t *)buffer;
    block_size = RT_AUDIO_REPLAY_MP_BLOCK_SIZE;

    rt_mutex_take(&audio->replay->lock, RT_WAITING_FOREVER);
    while (index < size)
    {
        /* request buffer from replay memory pool */
        if (audio->replay->write_index % block_size == 0)
        {
            audio->replay->write_data = rt_mp_alloc(audio->replay->mp, RT_WAITING_FOREVER);
            rt_memset(audio->replay->write_data, 0, block_size);
        }

        /* copy data to replay memory pool */
        remain_bytes = MIN((block_size - audio->replay->write_index), (size - index));
        rt_memcpy(&audio->replay->write_data[audio->replay->write_index], &ptr[index], remain_bytes);

        index += remain_bytes;
        audio->replay->write_index += remain_bytes;
        audio->replay->write_index %= block_size;

        if (audio->replay->write_index == 0)
        {
            rt_data_queue_push(&audio->replay->queue,
                               audio->replay->write_data,
                               block_size,
                               RT_WAITING_FOREVER);
        }
    }
    rt_mutex_release(&audio->replay->lock);

    /* check replay state */
    if (audio->replay->activated != RT_TRUE)
    {
        _aduio_replay_start(audio);
        audio->replay->activated = RT_TRUE;
    }

    return index;
}

/**
 * @brief Control audio device