diff --git a/drivers/mfd/tc6387xb.c b/drivers/mfd/tc6387xb.c
index ad715bf..71bc835 100644
--- a/drivers/mfd/tc6387xb.c
+++ b/drivers/mfd/tc6387xb.c
@@ -177,7 +177,7 @@
 	if (ret)
 		goto err_resource;
 
-	tc6387xb->scr = ioremap(rscr->start, rscr->end - rscr->start + 1);
+	tc6387xb->scr = ioremap(rscr->start, resource_size(rscr));
 	if (!tc6387xb->scr) {
 		ret = -ENOMEM;
 		goto err_ioremap;