devm_qmc_chan_get_bychild
qmc_hdlc->qmc_chan = devm_qmc_chan_get_bychild(dev, dev->of_node);
EXPORT_SYMBOL(devm_qmc_chan_get_bychild);
struct qmc_chan *devm_qmc_chan_get_bychild(struct device *dev, struct device_node *np);