diff --git a/drivers/spi/spi-ath79.c b/drivers/spi/spi-ath79.c
index fcff810..03019bf 100644
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -232,7 +232,7 @@
 		goto err_put_master;
 	}
 
-	sp->base = ioremap(r->start, r->end - r->start + 1);
+	sp->base = ioremap(r->start, resource_size(r));
 	if (!sp->base) {
 		ret = -ENXIO;
 		goto err_put_master;