dsa/mv88e6xxx/port_hidden.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Marvell 88E6xxx Switch Hidden Registers support
0004  *
0005  * Copyright (c) 2008 Marvell Semiconductor
0006  *
0007  * Copyright (c) 2019 Andrew Lunn <andrew@lunn.ch>
0008  */
0009
0010 #include <linux/bitfield.h>
0011
0012 #include "chip.h"
0013 #include "port.h"
0014
0015 /* The mv88e6390 and mv88e6341 have some hidden registers used for debug and
0016  * development. The errata also makes use of them.
0017  */
0018 int mv88e6xxx_port_hidden_write(struct mv88e6xxx_chip *chip, int block,
0019                 int port, int reg, u16 val)
0020 {
0021     u16 ctrl;
0022     int err;
0023
0024     err = mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_DATA_PORT,
0025                    MV88E6XXX_PORT_RESERVED_1A, val);
0026     if (err)
0027         return err;
0028
0029     ctrl = MV88E6XXX_PORT_RESERVED_1A_BUSY |
0030            MV88E6XXX_PORT_RESERVED_1A_WRITE |
0031            block << MV88E6XXX_PORT_RESERVED_1A_BLOCK_SHIFT |
0032            port << MV88E6XXX_PORT_RESERVED_1A_PORT_SHIFT |
0033            reg;
0034
0035     return mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
0036                     MV88E6XXX_PORT_RESERVED_1A, ctrl);
0037 }
0038
0039 int mv88e6xxx_port_hidden_wait(struct mv88e6xxx_chip *chip)
0040 {
0041     int bit = __bf_shf(MV88E6XXX_PORT_RESERVED_1A_BUSY);
0042
0043     return mv88e6xxx_port_wait_bit(chip,
0044                        MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
0045                        MV88E6XXX_PORT_RESERVED_1A, bit, 0);
0046 }
0047
0048 int mv88e6xxx_port_hidden_read(struct mv88e6xxx_chip *chip, int block, int port,
0049                    int reg, u16 *val)
0050 {
0051     u16 ctrl;
0052     int err;
0053
0054     ctrl = MV88E6XXX_PORT_RESERVED_1A_BUSY |
0055            MV88E6XXX_PORT_RESERVED_1A_READ |
0056            block << MV88E6XXX_PORT_RESERVED_1A_BLOCK_SHIFT |
0057            port << MV88E6XXX_PORT_RESERVED_1A_PORT_SHIFT |
0058            reg;
0059
0060     err = mv88e6xxx_port_write(chip, MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
0061                    MV88E6XXX_PORT_RESERVED_1A, ctrl);
0062     if (err)
0063         return err;
0064
0065     err = mv88e6xxx_port_hidden_wait(chip);
0066     if (err)
0067         return err;
0068
0069     return mv88e6xxx_port_read(chip, MV88E6XXX_PORT_RESERVED_1A_DATA_PORT,
0070                    MV88E6XXX_PORT_RESERVED_1A, val);
0071 }