1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2000-2010
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 *
6 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
7 * Andreas Heppel <aheppel@sysgo.de>
8 */
9
10 #include <common.h>
11 #include <command.h>
12 #include <environment.h>
13 #include <linux/stddef.h>
14 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
15 #include <i2c.h>
16 #endif
17 #include <search.h>
18 #include <errno.h>
19 #include <linux/compiler.h> /* for BUG_ON */
20
21 DECLARE_GLOBAL_DATA_PTR;
22
eeprom_bus_read(unsigned dev_addr,unsigned offset,uchar * buffer,unsigned cnt)23 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
24 uchar *buffer, unsigned cnt)
25 {
26 int rcode;
27 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
28 int old_bus = i2c_get_bus_num();
29
30 if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
31 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
32 #endif
33
34 rcode = eeprom_read(dev_addr, offset, buffer, cnt);
35
36 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
37 i2c_set_bus_num(old_bus);
38 #endif
39
40 return rcode;
41 }
42
eeprom_bus_write(unsigned dev_addr,unsigned offset,uchar * buffer,unsigned cnt)43 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
44 uchar *buffer, unsigned cnt)
45 {
46 int rcode;
47 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
48 int old_bus = i2c_get_bus_num();
49
50 if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
51 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
52 #endif
53
54 rcode = eeprom_write(dev_addr, offset, buffer, cnt);
55
56 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
57 i2c_set_bus_num(old_bus);
58 #endif
59
60 return rcode;
61 }
62
63 /** Call this function from overridden env_get_char_spec() if you need
64 * this functionality.
65 */
env_eeprom_get_char(int index)66 int env_eeprom_get_char(int index)
67 {
68 uchar c;
69 unsigned int off = CONFIG_ENV_OFFSET;
70
71 #ifdef CONFIG_ENV_OFFSET_REDUND
72 if (gd->env_valid == ENV_REDUND)
73 off = CONFIG_ENV_OFFSET_REDUND;
74 #endif
75 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
76 off + index + offsetof(env_t, data), &c, 1);
77
78 return c;
79 }
80
env_eeprom_load(void)81 static int env_eeprom_load(void)
82 {
83 char buf_env[CONFIG_ENV_SIZE];
84 unsigned int off = CONFIG_ENV_OFFSET;
85
86 #ifdef CONFIG_ENV_OFFSET_REDUND
87 ulong len, crc[2], crc_tmp;
88 unsigned int off_env[2];
89 uchar rdbuf[64], flags[2];
90 int i, crc_ok[2] = {0, 0};
91
92 eeprom_init(-1); /* prepare for EEPROM read/write */
93
94 off_env[0] = CONFIG_ENV_OFFSET;
95 off_env[1] = CONFIG_ENV_OFFSET_REDUND;
96
97 for (i = 0; i < 2; i++) {
98 /* read CRC */
99 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
100 off_env[i] + offsetof(env_t, crc),
101 (uchar *)&crc[i], sizeof(ulong));
102 /* read FLAGS */
103 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
104 off_env[i] + offsetof(env_t, flags),
105 (uchar *)&flags[i], sizeof(uchar));
106
107 crc_tmp = 0;
108 len = ENV_SIZE;
109 off = off_env[i] + offsetof(env_t, data);
110 while (len > 0) {
111 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
112
113 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
114 rdbuf, n);
115
116 crc_tmp = crc32(crc_tmp, rdbuf, n);
117 len -= n;
118 off += n;
119 }
120
121 if (crc_tmp == crc[i])
122 crc_ok[i] = 1;
123 }
124
125 if (!crc_ok[0] && !crc_ok[1]) {
126 gd->env_addr = 0;
127 gd->env_valid = ENV_INVALID;
128 } else if (crc_ok[0] && !crc_ok[1]) {
129 gd->env_valid = ENV_VALID;
130 } else if (!crc_ok[0] && crc_ok[1]) {
131 gd->env_valid = ENV_REDUND;
132 } else {
133 /* both ok - check serial */
134 if (flags[0] == ACTIVE_FLAG && flags[1] == OBSOLETE_FLAG)
135 gd->env_valid = ENV_VALID;
136 else if (flags[0] == OBSOLETE_FLAG && flags[1] == ACTIVE_FLAG)
137 gd->env_valid = ENV_REDUND;
138 else if (flags[0] == 0xFF && flags[1] == 0)
139 gd->env_valid = ENV_REDUND;
140 else if (flags[1] == 0xFF && flags[0] == 0)
141 gd->env_valid = ENV_VALID;
142 else /* flags are equal - almost impossible */
143 gd->env_valid = ENV_VALID;
144 }
145
146 #else /* CONFIG_ENV_OFFSET_REDUND */
147 ulong crc, len, new;
148 uchar rdbuf[64];
149
150 eeprom_init(-1); /* prepare for EEPROM read/write */
151
152 /* read old CRC */
153 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
154 CONFIG_ENV_OFFSET + offsetof(env_t, crc),
155 (uchar *)&crc, sizeof(ulong));
156
157 new = 0;
158 len = ENV_SIZE;
159 off = offsetof(env_t, data);
160 while (len > 0) {
161 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
162
163 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
164 CONFIG_ENV_OFFSET + off, rdbuf, n);
165 new = crc32(new, rdbuf, n);
166 len -= n;
167 off += n;
168 }
169
170 if (crc == new) {
171 gd->env_valid = ENV_VALID;
172 } else {
173 gd->env_valid = ENV_INVALID;
174 }
175 #endif /* CONFIG_ENV_OFFSET_REDUND */
176
177 off = CONFIG_ENV_OFFSET;
178 #ifdef CONFIG_ENV_OFFSET_REDUND
179 if (gd->env_valid == ENV_REDUND)
180 off = CONFIG_ENV_OFFSET_REDUND;
181 #endif
182
183 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
184 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
185
186 return env_import(buf_env, 1);
187 }
188
env_eeprom_save(void)189 static int env_eeprom_save(void)
190 {
191 env_t env_new;
192 int rc;
193 unsigned int off = CONFIG_ENV_OFFSET;
194 #ifdef CONFIG_ENV_OFFSET_REDUND
195 unsigned int off_red = CONFIG_ENV_OFFSET_REDUND;
196 char flag_obsolete = OBSOLETE_FLAG;
197 #endif
198
199 rc = env_export(&env_new);
200 if (rc)
201 return rc;
202
203 #ifdef CONFIG_ENV_OFFSET_REDUND
204 if (gd->env_valid == ENV_VALID) {
205 off = CONFIG_ENV_OFFSET_REDUND;
206 off_red = CONFIG_ENV_OFFSET;
207 }
208
209 env_new.flags = ACTIVE_FLAG;
210 #endif
211
212 rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
213 off, (uchar *)&env_new, CONFIG_ENV_SIZE);
214
215 #ifdef CONFIG_ENV_OFFSET_REDUND
216 if (rc == 0) {
217 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
218 off_red + offsetof(env_t, flags),
219 (uchar *)&flag_obsolete, 1);
220
221 if (gd->env_valid == ENV_VALID)
222 gd->env_valid = ENV_REDUND;
223 else
224 gd->env_valid = ENV_VALID;
225 }
226 #endif
227 return rc;
228 }
229
230 U_BOOT_ENV_LOCATION(eeprom) = {
231 .location = ENVL_EEPROM,
232 ENV_NAME("EEPROM")
233 .load = env_eeprom_load,
234 .save = env_save_ptr(env_eeprom_save),
235 };
236