+static int hbg_mdio_cmd_send(struct hbg_mac *mac, u32 prt_addr, u32 dev_addr,
+			     u32 type, u32 op_code)
+{
+	struct hbg_mdio_command mdio_cmd;
+
+	hbg_mdio_get_command(mac, &mdio_cmd);
+	mdio_cmd.mdio_st = type;
+	/* if auto scan enabled, this value need fix to 0 */
+	mdio_cmd.mdio_start = 0x1;
+	mdio_cmd.mdio_op = op_code;
+	mdio_cmd.mdio_prtad = prt_addr;
+	mdio_cmd.mdio_devad = dev_addr;
+	hbg_mdio_set_command(mac, &mdio_cmd);
+
+	/* wait operation complete and check the result */
+	return hbg_mdio_check_send_result(mac);

+struct hbg_mdio_command {
+	union {
+		struct {
+			u32 mdio_devad : 5;
+			u32 mdio_prtad :5;
+			u32 mdio_op : 2;
+			u32 mdio_st : 2;
+			u32 mdio_start : 1;
+			u32 mdio_clk_sel : 1;
+			u32 mdio_auto_scan : 1;
+			u32 mdio_clk_sel_exp : 1;
+			u32 rev : 14;
+		};
+		u32 bits;
+	};
+};

This is generally not the way to do this. Please look at the macros in
include/linux/bitfield.h. FIELD_PREP, GENMASK, BIT, FIELD_GET
etc. These are guaranteed to work for both big and little endian, and
you avoid issues where the compiler decides to add padding in your
bitfields.

	Andrew