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_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 }