fdt: Add a function to decode a named memory region
Permit decoding of a named memory region from the device tree. This allows
easy run-time configuration of the address of on-chip SRAM, SDRAM, etc.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 4dbd6ae..9c332ad 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -793,4 +793,65 @@
return 0;
}
+
+int fdtdec_decode_memory_region(const void *blob, int config_node,
+ const char *mem_type, const char *suffix,
+ fdt_addr_t *basep, fdt_size_t *sizep)
+{
+ char prop_name[50];
+ const char *mem;
+ fdt_size_t size, offset_size;
+ fdt_addr_t base, offset;
+ int node;
+
+ if (config_node == -1) {
+ config_node = fdt_path_offset(blob, "/config");
+ if (config_node < 0) {
+ debug("%s: Cannot find /config node\n", __func__);
+ return -ENOENT;
+ }
+ }
+ if (!suffix)
+ suffix = "";
+
+ snprintf(prop_name, sizeof(prop_name), "%s-memory%s", mem_type,
+ suffix);
+ mem = fdt_getprop(blob, config_node, prop_name, NULL);
+ if (!mem) {
+ debug("%s: No memory type for '%s', using /memory\n", __func__,
+ prop_name);
+ mem = "/memory";
+ }
+
+ node = fdt_path_offset(blob, mem);
+ if (node < 0) {
+ debug("%s: Failed to find node '%s': %s\n", __func__, mem,
+ fdt_strerror(node));
+ return -ENOENT;
+ }
+
+ /*
+ * Not strictly correct - the memory may have multiple banks. We just
+ * use the first
+ */
+ if (fdtdec_decode_region(blob, node, "reg", &base, &size)) {
+ debug("%s: Failed to decode memory region %s\n", __func__,
+ mem);
+ return -EINVAL;
+ }
+
+ snprintf(prop_name, sizeof(prop_name), "%s-offset%s", mem_type,
+ suffix);
+ if (fdtdec_decode_region(blob, config_node, prop_name, &offset,
+ &offset_size)) {
+ debug("%s: Failed to decode memory region '%s'\n", __func__,
+ prop_name);
+ return -EINVAL;
+ }
+
+ *basep = base + offset;
+ *sizep = offset_size;
+
+ return 0;
+}
#endif