1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Marvell 88E6xxx Switch Hidden Registers support
4 *
5 * Copyright (c) 2008 Marvell Semiconductor
6 *
7 * Copyright (c) 2019 Andrew Lunn <andrew@lunn.ch>
8 */
9
10#include <linux/bitfield.h>
11
12#include "chip.h"
13#include "port.h"
14
15/* The mv88e6390 and mv88e6341 have some hidden registers used for debug and
16 * development. The errata also makes use of them.
17 */
18int mv88e6xxx_port_hidden_write(struct mv88e6xxx_chip *chip, int block,
19				int port, int reg, u16 val)
20{
21	u16 ctrl;
22	int err;
23
24	err = mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_DATA_PORT,
25				   MV88E6XXX_PORT_RESERVED_1A, val);
26	if (err)
27		return err;
28
29	ctrl = MV88E6XXX_PORT_RESERVED_1A_BUSY |
30	       MV88E6XXX_PORT_RESERVED_1A_WRITE |
31	       block << MV88E6XXX_PORT_RESERVED_1A_BLOCK_SHIFT |
32	       port << MV88E6XXX_PORT_RESERVED_1A_PORT_SHIFT |
33	       reg;
34
35	return mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
36				    MV88E6XXX_PORT_RESERVED_1A, ctrl);
37}
38
39int mv88e6xxx_port_hidden_wait(struct mv88e6xxx_chip *chip)
40{
41	int bit = __bf_shf(MV88E6XXX_PORT_RESERVED_1A_BUSY);
42
43	return mv88e6xxx_port_wait_bit(chip,
44				       MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
45				       MV88E6XXX_PORT_RESERVED_1A, bit, 0);
46}
47
48int mv88e6xxx_port_hidden_read(struct mv88e6xxx_chip *chip, int block, int port,
49			       int reg, u16 *val)
50{
51	u16 ctrl;
52	int err;
53
54	ctrl = MV88E6XXX_PORT_RESERVED_1A_BUSY |
55	       MV88E6XXX_PORT_RESERVED_1A_READ |
56	       block << MV88E6XXX_PORT_RESERVED_1A_BLOCK_SHIFT |
57	       port << MV88E6XXX_PORT_RESERVED_1A_PORT_SHIFT |
58	       reg;
59
60	err = mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
61				   MV88E6XXX_PORT_RESERVED_1A, ctrl);
62	if (err)
63		return err;
64
65	err = mv88e6xxx_port_hidden_wait(chip);
66	if (err)
67		return err;
68
69	return mv88e6xxx_port_read(chip, MV88E6XXX_PORT_RESERVED_1A_DATA_PORT,
70				   MV88E6XXX_PORT_RESERVED_1A, val);
71}
72