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_wait_bit(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
44				  MV88E6XXX_PORT_RESERVED_1A, bit, 0);
45}
46
47int mv88e6xxx_port_hidden_read(struct mv88e6xxx_chip *chip, int block, int port,
48			       int reg, u16 *val)
49{
50	u16 ctrl;
51	int err;
52
53	ctrl = MV88E6XXX_PORT_RESERVED_1A_BUSY |
54	       MV88E6XXX_PORT_RESERVED_1A_READ |
55	       block << MV88E6XXX_PORT_RESERVED_1A_BLOCK_SHIFT |
56	       port << MV88E6XXX_PORT_RESERVED_1A_PORT_SHIFT |
57	       reg;
58
59	err = mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
60				   MV88E6XXX_PORT_RESERVED_1A, ctrl);
61	if (err)
62		return err;
63
64	err = mv88e6xxx_port_hidden_wait(chip);
65	if (err)
66		return err;
67
68	return mv88e6xxx_port_read(chip, MV88E6XXX_PORT_RESERVED_1A_DATA_PORT,
69				   MV88E6XXX_PORT_RESERVED_1A, val);
70}