Function serial_fops_read

components/drivers/serial/dev_serial.c:147–180

static ssize_t serial_fops_read(struct dfs_file *fd, void *buf, size_t count, off_t *pos)
#else
static ssize_t serial_fops_read(struct dfs_file *fd, void *buf, size_t count)
#endif
{
    int size = 0;
    rt_device_t device;
    int wait_ret;

    device = (rt_device_t)fd->vnode->data;

    do
    {
        size = rt_device_read(device, -1,  buf, count);
        if (size <= 0)
        {
            if (fd->flags & O_NONBLOCK)
            {
                size = -EAGAIN;
                break;
            }

            wait_ret = rt_wqueue_wait_interruptible(&(device->wait_queue), 0, RT_WAITING_FOREVER);
            if (wait_ret != RT_EOK)
            {
                break;
            }
        }
    }while (size <= 0);

    if (size < 0)
    {
        size = 0;
    }
    return size;
}

#ifdef RT_USING_DFS_V2
static ssize_t serial_fops_write(struct dfs_file *fd, const void *buf, size_t count, off_t *pos)