diff --git a/drivers/staging/comedi/drivers/cb_pcimdda.c b/drivers/staging/comedi/drivers/cb_pcimdda.c
index bf98af450f0e..765f92cab8da 100644
--- a/drivers/staging/comedi/drivers/cb_pcimdda.c
+++ b/drivers/staging/comedi/drivers/cb_pcimdda.c
@@ -92,6 +92,12 @@ Configuration Options:
 #define PCI_VENDOR_ID_COMPUTERBOARDS	0x1307
 #define PCI_ID_PCIM_DDA06_16		0x0053
 
+/*
+ * Register map, 8-bit access only
+ */
+#define PCIMDDA_DA_CHAN(x)		(0x00 + (x) * 2)
+#define PCIMDDA_8255_BASE_REG		0x0c
+
 /*
  * This is straight from skel.c -- I did this in case this source file
  * will someday support more than 1 board...