+/* Register operations */
+#define MII_KSZ9031_MOD_REG 0x0000
+/* Data operations */
+#define MII_KSZ9031_MOD_DATA_NO_POST_INC 0x4000
+#define MII_KSZ9031_MOD_DATA_POST_INC_RW 0x8000
+#define MII_KSZ9031_MOD_DATA_POST_INC_W 0xC000
+
+#define MII_KSZ9031_EXT_RGMII_CTRL_SIG_SKEW 0x4
+#define MII_KSZ9031_EXT_RGMII_RX_DATA_SKEW 0x5
+#define MII_KSZ9031_EXT_RGMII_TX_DATA_SKEW 0x6
+#define MII_KSZ9031_EXT_RGMII_CLOCK_SKEW 0x8