regmap: Improve error handling

ofnode_read_simple_addr_cells may fail and return a negative error code.
Check for this when initializing regmaps.

Also check if both_len is zero, since this is perfectly possible, and
would lead to a division-by-zero further down the line.

Reviewed-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mario Six <mario.six@gdsys.cc>

diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
index 77f6f52..4ebab23 100644 (file)
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@@ -67,8 +67,25 @@ int regmap_init_mem(ofnode node, struct regmap **mapp)
        struct resource r;
 
        addr_len = ofnode_read_simple_addr_cells(ofnode_get_parent(node));
+       if (addr_len < 0) {
+               debug("%s: Error while reading the addr length (ret = %d)\n",
+                     ofnode_get_name(node), addr_len);
+               return addr_len;
+       }
+
        size_len = ofnode_read_simple_size_cells(ofnode_get_parent(node));
+       if (size_len < 0) {
+               debug("%s: Error while reading the size length: (ret = %d)\n",
+                     ofnode_get_name(node), size_len);
+               return size_len;
+       }
+
        both_len = addr_len + size_len;
+       if (!both_len) {
+               debug("%s: Both addr and size length are zero\n",
+                     ofnode_get_name(node));
+               return -EINVAL;
+       }
 
        len = ofnode_read_size(node, "reg");
        if (len < 0)