From 684204593d9b81ba4cd4c441b5ee395a29cff606 Mon Sep 17 00:00:00 2001 From: Peter Crosthwaite Date: Mon, 4 Jul 2016 13:06:36 +0100 Subject: register: Define REG and FIELD macros Define some macros that can be used for defining registers and fields. The REG32 macro will define A_FOO, for the byte address of a register as well as R_FOO for the uint32_t[] register number (A_FOO / 4). The FIELD macro will define FOO_BAR_MASK, FOO_BAR_SHIFT and FOO_BAR_LENGTH constants for field BAR in register FOO. Finally, there are some shorthand helpers for extracting/depositing fields from registers based on these naming schemes. Usage can greatly reduce the verbosity of device code. The deposit and extract macros (eg FIELD_EX32, FIELD_DP32 etc.) can be used to generate extract and deposits without any repetition of the name stems. Signed-off-by: Peter Crosthwaite Reviewed-by: Peter Maydell Signed-off-by: Alistair Francis Signed-off-by: Edgar E. Iglesias Message-id: bbd87a3c03b1f173b1ed73a6d502c0196c18a72f.1467053537.git.alistair.francis@xilinx.com [ EI Changes: * Add Deposit macros ] Signed-off-by: Edgar E. Iglesias Signed-off-by: Alistair Francis Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- include/hw/register.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/include/hw/register.h b/include/hw/register.h index 00bbfe5997..e8c58a1dbb 100644 --- a/include/hw/register.h +++ b/include/hw/register.h @@ -152,4 +152,50 @@ void register_write_memory(void *opaque, hwaddr addr, uint64_t value, uint64_t register_read_memory(void *opaque, hwaddr addr, unsigned size); +/* Define constants for a 32 bit register */ + +/* This macro will define A_FOO, for the byte address of a register + * as well as R_FOO for the uint32_t[] register number (A_FOO / 4). + */ +#define REG32(reg, addr) \ + enum { A_ ## reg = (addr) }; \ + enum { R_ ## reg = (addr) / 4 }; + +/* Define SHIFT, LENGTH and MASK constants for a field within a register */ + +/* This macro will define FOO_BAR_MASK, FOO_BAR_SHIFT and FOO_BAR_LENGTH + * constants for field BAR in register FOO. + */ +#define FIELD(reg, field, shift, length) \ + enum { R_ ## reg ## _ ## field ## _SHIFT = (shift)}; \ + enum { R_ ## reg ## _ ## field ## _LENGTH = (length)}; \ + enum { R_ ## reg ## _ ## field ## _MASK = \ + MAKE_64BIT_MASK(shift, length)}; + +/* Extract a field from a register */ +#define FIELD_EX32(storage, reg, field) \ + extract32((storage), R_ ## reg ## _ ## field ## _SHIFT, \ + R_ ## reg ## _ ## field ## _LENGTH) + +/* Extract a field from an array of registers */ +#define ARRAY_FIELD_EX32(regs, reg, field) \ + FIELD_EX32((regs)[R_ ## reg], reg, field) + +/* Deposit a register field. + * Assigning values larger then the target field will result in + * compilation warnings. + */ +#define FIELD_DP32(storage, reg, field, val) ({ \ + struct { \ + unsigned int v:R_ ## reg ## _ ## field ## _LENGTH; \ + } v = { .v = val }; \ + uint32_t d; \ + d = deposit32((storage), R_ ## reg ## _ ## field ## _SHIFT, \ + R_ ## reg ## _ ## field ## _LENGTH, v.v); \ + d; }) + +/* Deposit a field to array of registers. */ +#define ARRAY_FIELD_DP32(regs, reg, field, val) \ + (regs)[R_ ## reg] = FIELD_DP32((regs)[R_ ## reg], reg, field, val); + #endif -- cgit v1.2.3