diff --git a/drivers/mfd/asic3.c b/drivers/mfd/asic3.c
index 52e56ea..c27fd1f 100644
--- a/drivers/mfd/asic3.c
+++ b/drivers/mfd/asic3.c
@@ -856,7 +856,8 @@
 
 	/* MMC */
 	asic->tmio_cnf = ioremap((ASIC3_SD_CONFIG_BASE >> asic->bus_shift) +
-				 mem_sdio->start, 0x400 >> asic->bus_shift);
+				 mem_sdio->start,
+				 ASIC3_SD_CONFIG_SIZE >> asic->bus_shift);
 	if (!asic->tmio_cnf) {
 		ret = -ENOMEM;
 		dev_dbg(asic->dev, "Couldn't ioremap SD_CONFIG\n");
diff --git a/include/linux/mfd/asic3.h b/include/linux/mfd/asic3.h
index d0dd3eb..ed793b7 100644
--- a/include/linux/mfd/asic3.h
+++ b/include/linux/mfd/asic3.h
@@ -297,6 +297,7 @@
  *
  *****************************************************************************/
 #define ASIC3_SD_CONFIG_BASE	0x0400 /* Assumes 32 bit addressing */
+#define ASIC3_SD_CONFIG_SIZE	0x0200 /* Assumes 32 bit addressing */
 #define ASIC3_SD_CTRL_BASE	0x1000
 #define ASIC3_SDIO_CTRL_BASE	0x1200