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 */ 18 int 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 39 int 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 47 int 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 } 71