__of_get_dma_parent
parent = __of_get_dma_parent(np);
ret = __of_translate_address(dev, __of_get_dma_parent,
struct device_node *parent __free(device_node) = __of_get_dma_parent(dev);
bus_np = __of_get_dma_parent(np);
struct device_node *__of_get_dma_parent(const struct device_node *np);