include/hw/registerfields.h

   1 /*
   2  * Register Definition API: field macros
   3  *
   4  * Copyright (c) 2016 Xilinx Inc.
   5  * Copyright (c) 2013 Peter Crosthwaite <peter.crosthwaite@xilinx.com>
   6  *
   7  * This work is licensed under the terms of the GNU GPL, version 2.  See
   8  * the COPYING file in the top-level directory.
   9  */
  10
  11 #ifndef REGISTERFIELDS_H
  12 #define REGISTERFIELDS_H
  13
  14 /* Define constants for a 32 bit register */
  15
  16 /* This macro will define A_FOO, for the byte address of a register
  17  * as well as R_FOO for the uint32_t[] register number (A_FOO / 4).
  18  */
  19 #define REG32(reg, addr)                                                  \
  20     enum { A_ ## reg = (addr) };                                          \
  21     enum { R_ ## reg = (addr) / 4 };
  22
  23 /* Define SHIFT, LENGTH and MASK constants for a field within a register */
  24
  25 /* This macro will define FOO_BAR_MASK, FOO_BAR_SHIFT and FOO_BAR_LENGTH
  26  * constants for field BAR in register FOO.
  27  */
  28 #define FIELD(reg, field, shift, length)                                  \
  29     enum { R_ ## reg ## _ ## field ## _SHIFT = (shift)};                  \
  30     enum { R_ ## reg ## _ ## field ## _LENGTH = (length)};                \
  31     enum { R_ ## reg ## _ ## field ## _MASK =                             \
  32                                         MAKE_64BIT_MASK(shift, length)};
  33
  34 /* Extract a field from a register */
  35 #define FIELD_EX32(storage, reg, field)                                   \
  36     extract32((storage), R_ ## reg ## _ ## field ## _SHIFT,               \
  37               R_ ## reg ## _ ## field ## _LENGTH)
  38
  39 /* Extract a field from an array of registers */
  40 #define ARRAY_FIELD_EX32(regs, reg, field)                                \
  41     FIELD_EX32((regs)[R_ ## reg], reg, field)
  42
  43 /* Deposit a register field.
  44  * Assigning values larger then the target field will result in
  45  * compilation warnings.
  46  */
  47 #define FIELD_DP32(storage, reg, field, val) ({                           \
  48     struct {                                                              \
  49         unsigned int v:R_ ## reg ## _ ## field ## _LENGTH;                \
  50     } v = { .v = val };                                                   \
  51     uint32_t d;                                                           \
  52     d = deposit32((storage), R_ ## reg ## _ ## field ## _SHIFT,           \
  53                   R_ ## reg ## _ ## field ## _LENGTH, v.v);               \
  54     d; })
  55
  56 /* Deposit a field to array of registers.  */
  57 #define ARRAY_FIELD_DP32(regs, reg, field, val)                           \
  58     (regs)[R_ ## reg] = FIELD_DP32((regs)[R_ ## reg], reg, field, val);
  59
  60 #endif