Software APIs
abs_mmio.h
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1// Copyright lowRISC contributors (OpenTitan project).
2// Licensed under the Apache License, Version 2.0, see LICENSE for details.
3// SPDX-License-Identifier: Apache-2.0
4
5#ifndef OPENTITAN_SW_DEVICE_LIB_BASE_ABS_MMIO_H_
6#define OPENTITAN_SW_DEVICE_LIB_BASE_ABS_MMIO_H_
7
8#include <stddef.h>
9#include <stdint.h>
10
11#include "sw/device/lib/base/macros.h"
12
13#ifdef __cplusplus
14extern "C" {
15#endif
16
17/**
18 * @file
19 * @brief Absolute Memory-mapped IO functions, for volatile access.
20 *
21 * Memory-mapped IO functions, which map to volatile accesses. Use this module
22 * for register operations in ROM and ROM Extension production libraries.
23 *
24 * Compiling translation units that pull in this header with `-DMOCK_ABS_MMIO`
25 * will disable the definitions of `abs_mmio_read` and `abs_mmio_write`. These
26 * symbols can then be defined by a test harness to allow for instrumentation of
27 * MMIO accesses.
28 */
29
30#ifdef OT_PLATFORM_RV32
31
32/**
33 * Reads uint8_t from MMIO `addr`.
34 *
35 * @param addr the address to read from.
36 * @return the read value.
37 */
38OT_WARN_UNUSED_RESULT
39inline uint8_t abs_mmio_read8(uint32_t addr) {
40 return *((volatile uint8_t *)addr);
41}
42
43/**
44 * Writes uint8_t to the MMIO `addr`.
45 *
46 * @param addr the address to write to.
47 * @param value the value to write.
48 */
49inline void abs_mmio_write8(uint32_t addr, uint8_t value) {
50 *((volatile uint8_t *)addr) = value;
51}
52
53/**
54 * Writes uint8_t to the MMIO `addr` via
55 * two subsequent write operations.
56 *
57 * @param addr the address to write to.
58 * @param value the value to write.
59 */
60inline void abs_mmio_write8_shadowed(uint32_t addr, uint8_t value) {
61 *((volatile uint8_t *)addr) = value;
62 *((volatile uint8_t *)addr) = value;
63}
64
65/**
66 * Reads an aligned uint32_t from MMIO `addr`.
67 *
68 * @param addr the address to read from.
69 * @return the read value.
70 */
71OT_WARN_UNUSED_RESULT
72inline uint32_t abs_mmio_read32(uint32_t addr) {
73 return *((volatile uint32_t *)addr);
74}
75
76/**
77 * Writes an aligned uint32_t to the MMIO `addr`.
78 *
79 * @param addr the address to write to.
80 * @param value the value to write.
81 */
82inline void abs_mmio_write32(uint32_t addr, uint32_t value) {
83 *((volatile uint32_t *)addr) = value;
84}
85
86/**
87 * Writes an aligned uint32_t to the MMIO `addr` via
88 * two subsequent write operations.
89 *
90 * @param addr the address to write to.
91 * @param value the value to write.
92 */
93inline void abs_mmio_write32_shadowed(uint32_t addr, uint32_t value) {
94 *((volatile uint32_t *)addr) = value;
95 *((volatile uint32_t *)addr) = value;
96}
97
98#else // OT_PLATFORM_RV32
99
100extern uint8_t abs_mmio_read8(uint32_t addr);
101extern void abs_mmio_write8(uint32_t addr, uint8_t value);
102extern void abs_mmio_write8_shadowed(uint32_t addr, uint8_t value);
103extern uint32_t abs_mmio_read32(uint32_t addr);
104extern void abs_mmio_write32(uint32_t addr, uint32_t value);
105extern void abs_mmio_write32_shadowed(uint32_t addr, uint32_t value);
106
107#endif // OT_PLATFORM_RV32
108
109#ifdef __cplusplus
110}
111#endif
112
113#endif // OPENTITAN_SW_DEVICE_LIB_BASE_ABS_MMIO_H_