I have resolved this, I have forgot to open can device in simple_can_open(). so this is how simple_can_open() looks now:

static int simple_can_open(struct net_device *dev)
{
    int err = open_candev(dev);
    if (err) {
        printk(KERN_WARNING "LXNAV %s can_dev: Failed opening\n", MODULE_NAME);
        return err;
    }
    netif_start_queue(dev);
    printk(KERN_INFO "DEBUG %s can_dev: device opened\n", MODULE_NAME);
    return 0;
}