1 /******************************************************************************
2 *
3 * Copyright (C) 2022-2023 Maxim Integrated Products, Inc. (now owned by
4 * Analog Devices, Inc.),
5 * Copyright (C) 2023-2024 Analog Devices, Inc.
6 *
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 *
19 ******************************************************************************/
20
21 #include <stdlib.h>
22 #include <string.h>
23
24 #include "mxc_sys.h"
25 #include "mxc_device.h"
26 #include "mxc_errors.h"
27 #include "mxc_assert.h"
28 #include "mxc_lock.h"
29
30 #include "trng_regs.h"
31 #include "trng.h"
32 #include "trng_reva.h"
33
34 /***** Global Variables *****/
35
36 static mxc_trng_complete_t MXC_TRNG_Callback;
37
38 static uint32_t TRNG_count, TRNG_maxLength;
39 static uint8_t *TRNG_data;
40
41 /* ************************************************************************* */
42 /* Global Control/Configuration functions */
43 /* ************************************************************************* */
44
MXC_TRNG_RevA_Init(void)45 int MXC_TRNG_RevA_Init(void)
46 {
47 MXC_TRNG_DisableInt();
48 return E_NO_ERROR;
49 }
50
MXC_TRNG_RevA_EnableInt(mxc_trng_reva_regs_t * trng)51 void MXC_TRNG_RevA_EnableInt(mxc_trng_reva_regs_t *trng)
52 {
53 trng->ctrl |= MXC_F_TRNG_REVA_CTRL_RNG_IE;
54 }
55
MXC_TRNG_RevA_DisableInt(mxc_trng_reva_regs_t * trng)56 void MXC_TRNG_RevA_DisableInt(mxc_trng_reva_regs_t *trng)
57 {
58 trng->ctrl &= ~MXC_F_TRNG_REVA_CTRL_RNG_IE;
59 }
60
MXC_TRNG_RevA_Shutdown(void)61 int MXC_TRNG_RevA_Shutdown(void)
62 {
63 return E_NO_ERROR;
64 }
65
MXC_TRNG_RevA_Handler(mxc_trng_reva_regs_t * trng)66 void MXC_TRNG_RevA_Handler(mxc_trng_reva_regs_t *trng)
67 {
68 uint32_t temp, remaining, i;
69 mxc_trng_complete_t cb;
70
71 // if this is last block, disable interrupt before reading trng->data
72 if (TRNG_maxLength <= TRNG_count + 4) {
73 trng->ctrl &= ~MXC_F_TRNG_REVA_CTRL_RNG_IE;
74 }
75
76 trng->ctrl |= MXC_S_TRNG_REVA_CTRL_RNG_ISC_CLEAR;
77 remaining = (TRNG_maxLength - TRNG_count) / 4;
78
79 if (remaining) {
80 for (i = 0; i < 4; i++) {
81 if (i >= remaining)
82 break;
83
84 temp = trng->data;
85 memcpy(&(TRNG_data[TRNG_count]), (uint8_t *)(&temp), 4);
86 TRNG_count += 4;
87 }
88 } else {
89 memcpy(&(TRNG_data[TRNG_count]), (uint8_t *)(&temp), TRNG_maxLength & 0x03);
90 TRNG_count += (TRNG_maxLength & 0x03);
91 }
92
93 if (TRNG_maxLength == TRNG_count) {
94 cb = MXC_TRNG_Callback;
95 cb(0, 0);
96 }
97 }
98
99 /* ************************************************************************* */
100 /* True Random Number Generator(TRNG) functions */
101 /* ************************************************************************* */
102
MXC_TRNG_RevA_RandomInt(mxc_trng_reva_regs_t * trng)103 int MXC_TRNG_RevA_RandomInt(mxc_trng_reva_regs_t *trng)
104 {
105 while (!(trng->ctrl & MXC_S_TRNG_REVA_CTRL_RNG_IS_READY)) {}
106
107 return (int)trng->data;
108 }
109
MXC_TRNG_RevA_Random(uint8_t * data,uint32_t len)110 int MXC_TRNG_RevA_Random(uint8_t *data, uint32_t len)
111 {
112 unsigned int i, temp;
113
114 if (data == NULL) {
115 return E_NULL_PTR;
116 }
117
118 for (i = 0; (i + 3) < len; i += 4) {
119 temp = MXC_TRNG_RandomInt();
120 memcpy(&(data[i]), (uint8_t *)(&temp), 4);
121 }
122
123 if (len & 0x03) {
124 temp = MXC_TRNG_RandomInt();
125 memcpy(&(data[i]), (uint8_t *)(&temp), len & 0x03);
126 }
127
128 return E_NO_ERROR;
129 }
130
MXC_TRNG_RevA_RandomAsync(mxc_trng_reva_regs_t * trng,uint8_t * data,uint32_t len,mxc_trng_complete_t callback)131 void MXC_TRNG_RevA_RandomAsync(mxc_trng_reva_regs_t *trng, uint8_t *data, uint32_t len,
132 mxc_trng_complete_t callback)
133 {
134 MXC_ASSERT(data && callback);
135
136 if (len == 0) {
137 return;
138 }
139
140 TRNG_data = data;
141 TRNG_count = 0;
142 TRNG_maxLength = len;
143 MXC_TRNG_Callback = callback;
144
145 // Enable interrupts
146 trng->ctrl |= MXC_F_TRNG_REVA_CTRL_RNG_IE;
147 }
148
MXC_TRNG_RevA_GenerateKey(mxc_trng_reva_regs_t * trng)149 void MXC_TRNG_RevA_GenerateKey(mxc_trng_reva_regs_t *trng)
150 {
151 /*Generate AES Key */
152 trng->ctrl |= MXC_F_TRNG_REVA_CTRL_AESKG;
153
154 while (trng->ctrl & MXC_F_TRNG_REVA_CTRL_AESKG) {}
155 }
156
