zircon/kernel/include/reg.h

// Copyright 2016 The Fuchsia Authors
// Copyright (c) 2008 Travis Geiselbrecht
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#ifndef ZIRCON_KERNEL_INCLUDE_REG_H_
#define ZIRCON_KERNEL_INCLUDE_REG_H_

#include <stdint.h>

/* low level macros for accessing memory mapped hardware registers */
#define REG64(addr) ((volatile uint64_t *)(uintptr_t)(addr))
#define REG32(addr) ((volatile uint32_t *)(uintptr_t)(addr))
#define REG16(addr) ((volatile uint16_t *)(uintptr_t)(addr))
#define REG8(addr) ((volatile uint8_t *)(uintptr_t)(addr))

#define RMWREG64(addr, startbit, width, val) \
  *REG64(addr) = (*REG64(addr) & ~(((1 << (width)) - 1) << (startbit))) | ((val) << (startbit))
#define RMWREG32(addr, startbit, width, val) \
  *REG32(addr) = (*REG32(addr) & ~(((1 << (width)) - 1) << (startbit))) | ((val) << (startbit))
#define RMWREG16(addr, startbit, width, val) \
  *REG16(addr) = (*REG16(addr) & ~(((1 << (width)) - 1) << (startbit))) | ((val) << (startbit))
#define RMWREG8(addr, startbit, width, val) \
  *REG8(addr) = (*REG8(addr) & ~(((1 << (width)) - 1) << (startbit))) | ((val) << (startbit))

#define writell(v, a) (*REG64(a) = (v))
#define readll(a) (*REG64(a))
#define writel(v, a) (*REG32(a) = (v))
#define readl(a) (*REG32(a))
#define writew(v, a) (*REG16(a) = (v))
#define readw(a) (*REG16(a))
#define writeb(v, a) (*REG8(a) = (v))
#define readb(a) (*REG8(a))

#endif  // ZIRCON_KERNEL_INCLUDE_REG_H_