fdt: Add fdtdec_decode_region() to decode memory region

A memory region has a start and a size and is often specified in
a node by a 'reg' property. Add a function to decode this information
from the fdt.

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

1 files changed, 17 insertions, 0 deletions

diff --git a/lib/fdtdec.c b/lib/fdtdec.c
index 2d60c8a..5570972 100644
--- a/lib/fdtdec.c
+++ b/lib/fdtdec.c
@@ -542,3 +542,20 @@ char *fdtdec_get_config_string(const void *blob, const char *prop_name)
 
 	return (char *)nodep;
 }
+
+int fdtdec_decode_region(const void *blob, int node,
+		const char *prop_name, void **ptrp, size_t *size)
+{
+	const fdt_addr_t *cell;
+	int len;
+
+	debug("%s: %s\n", __func__, prop_name);
+	cell = fdt_getprop(blob, node, prop_name, &len);
+	if (!cell || (len != sizeof(fdt_addr_t) * 2))
+		return -1;
+
+	*ptrp = (void *)fdt_addr_to_cpu(*cell);
+	*size = fdt_size_to_cpu(cell[1]);
+	debug("%s: size=%zx\n", __func__, *size);
+	return 0;
+}