dm: core: Add a function to decode a memory region

Add a way to decode a memory region, including the memory type (sram or
sdram) and its start address and size.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 81 insertions, 0 deletions

diff --git a/drivers/core/of_extra.c b/drivers/core/of_extra.c
index 3243caa5d12..aa48917dddf 100644
--- a/drivers/core/of_extra.c
+++ b/drivers/core/of_extra.c
@@ -34,3 +34,84 @@ int ofnode_read_fmap_entry(ofnode node, struct fmap_entry *entry)
 
 	return 0;
 }
+
+int ofnode_decode_region(ofnode node, const char *prop_name, fdt_addr_t *basep,
+			 fdt_size_t *sizep)
+{
+	const fdt_addr_t *cell;
+	int len;
+
+	debug("%s: %s: %s\n", __func__, ofnode_get_name(node), prop_name);
+	cell = ofnode_get_property(node, prop_name, &len);
+	if (!cell || (len < sizeof(fdt_addr_t) * 2)) {
+		debug("cell=%p, len=%d\n", cell, len);
+		return -1;
+	}
+
+	*basep = fdt_addr_to_cpu(*cell);
+	*sizep = fdt_size_to_cpu(cell[1]);
+	debug("%s: base=%08lx, size=%lx\n", __func__, (ulong)*basep,
+	      (ulong)*sizep);
+
+	return 0;
+}
+
+int ofnode_decode_memory_region(ofnode 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;
+	ofnode node;
+
+	if (!ofnode_valid(config_node)) {
+		config_node = ofnode_path("/config");
+		if (!ofnode_valid(config_node)) {
+			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 = ofnode_read_string(config_node, prop_name);
+	if (!mem) {
+		debug("%s: No memory type for '%s', using /memory\n", __func__,
+		      prop_name);
+		mem = "/memory";
+	}
+
+	node = ofnode_path(mem);
+	if (!ofnode_valid(node)) {
+		debug("%s: Failed to find node '%s'\n", __func__, mem);
+		return -ENOENT;
+	}
+
+	/*
+	 * Not strictly correct - the memory may have multiple banks. We just
+	 * use the first
+	 */
+	if (ofnode_decode_region(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 (ofnode_decode_region(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;
+}