diff --git a/drivers/staging/iio/cdc/ad7746.c b/drivers/staging/iio/cdc/ad7746.c
index 6cd15e65185afc056d2c59ae5b553c3035350609..2c5d27784ed300dfa5f090de08f487846bd59079 100644
--- a/drivers/staging/iio/cdc/ad7746.c
+++ b/drivers/staging/iio/cdc/ad7746.c
@@ -27,11 +27,7 @@
 
 #define AD7746_REG_STATUS		0
 #define AD7746_REG_CAP_DATA_HIGH	1
-#define AD7746_REG_CAP_DATA_MID		2
-#define AD7746_REG_CAP_DATA_LOW		3
 #define AD7746_REG_VT_DATA_HIGH		4
-#define AD7746_REG_VT_DATA_MID		5
-#define AD7746_REG_VT_DATA_LOW		6
 #define AD7746_REG_CAP_SETUP		7
 #define AD7746_REG_VT_SETUP		8
 #define AD7746_REG_EXC_SETUP		9
@@ -39,11 +35,8 @@
 #define AD7746_REG_CAPDACA		11
 #define AD7746_REG_CAPDACB		12
 #define AD7746_REG_CAP_OFFH		13
-#define AD7746_REG_CAP_OFFL		14
 #define AD7746_REG_CAP_GAINH		15
-#define AD7746_REG_CAP_GAINL		16
 #define AD7746_REG_VOLT_GAINH		17
-#define AD7746_REG_VOLT_GAINL		18
 
 /* Status Register Bit Designations (AD7746_REG_STATUS) */
 #define AD7746_STATUS_EXCERR		BIT(3)