drivers/net/dsa/mv88e6xxx/port_hidden.c

   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_port_wait_bit(chip,
  44                                        MV88E6XXX_PORT_RESERVED_1A_CTRL_PORT,
  45                                        MV88E6XXX_PORT_RESERVED_1A, bit, 0);
  46 }
  47
  48 int 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 }