+int fdt_get_dma_range(const void *blob, int node, phys_addr_t *cpu,
+ dma_addr_t *bus, u64 *size)
+{
+ bool found_dma_ranges = false;
+ struct of_bus *bus_node;
+ const fdt32_t *ranges;
+ int na, ns, pna, pns;
+ int parent = node;
+ int ret = 0;
+ int len;
+
+ /* Find the closest dma-ranges property */
+ while (parent >= 0) {
+ ranges = fdt_getprop(blob, parent, "dma-ranges", &len);
+
+ /* Ignore empty ranges, they imply no translation required */
+ if (ranges && len > 0)
+ break;
+
+ /* Once we find 'dma-ranges', then a missing one is an error */
+ if (found_dma_ranges && !ranges) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (ranges)
+ found_dma_ranges = true;
+
+ parent = fdt_parent_offset(blob, parent);
+ }
+
+ if (!ranges || parent < 0) {
+ debug("no dma-ranges found for node %s\n",
+ fdt_get_name(blob, node, NULL));
+ ret = -ENOENT;
+ goto out;
+ }
+
+ /* switch to that node */
+ node = parent;
+ parent = fdt_parent_offset(blob, node);
+ if (parent < 0) {
+ printf("Found dma-ranges in root node, shouldn't happen\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Get the address sizes both for the bus and its parent */
+ bus_node = of_match_bus(blob, node);
+ bus_node->count_cells(blob, node, &na, &ns);
+ if (!OF_CHECK_COUNTS(na, ns)) {
+ printf("%s: Bad cell count for %s\n", __FUNCTION__,
+ fdt_get_name(blob, node, NULL));
+ return -EINVAL;
+ goto out;
+ }
+
+ bus_node = of_match_bus(blob, parent);
+ bus_node->count_cells(blob, parent, &pna, &pns);
+ if (!OF_CHECK_COUNTS(pna, pns)) {
+ printf("%s: Bad cell count for %s\n", __FUNCTION__,
+ fdt_get_name(blob, parent, NULL));
+ return -EINVAL;
+ goto out;
+ }
+
+ *bus = fdt_read_number(ranges, na);
+ *cpu = fdt_translate_dma_address(blob, node, ranges + na);
+ *size = fdt_read_number(ranges + na + pna, ns);
+out:
+ return ret;
+}
+