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, val: 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, val: 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, val: 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

source code of linux/drivers/net/dsa/mv88e6xxx/port_hidden.c