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 <eeprom.h>
13 #include <env.h>
14 #include <env_internal.h>
15 #include <asm/global_data.h>
16 #include <linux/stddef.h>
17 #include <u-boot/crc.h>
18 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
19 #include <i2c.h>
20 #endif
21 #include <search.h>
22 #include <errno.h>
23 #include <linux/compiler.h> /* for BUG_ON */
24
25 DECLARE_GLOBAL_DATA_PTR;
26
eeprom_bus_read(unsigned dev_addr,unsigned offset,uchar * buffer,unsigned cnt)27 static int eeprom_bus_read(unsigned dev_addr, unsigned offset,
28 uchar *buffer, unsigned cnt)
29 {
30 int rcode;
31 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
32 int old_bus = i2c_get_bus_num();
33
34 if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
35 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
36 #endif
37
38 rcode = eeprom_read(dev_addr, offset, buffer, cnt);
39
40 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
41 i2c_set_bus_num(old_bus);
42 #endif
43
44 return rcode;
45 }
46
eeprom_bus_write(unsigned dev_addr,unsigned offset,uchar * buffer,unsigned cnt)47 static int eeprom_bus_write(unsigned dev_addr, unsigned offset,
48 uchar *buffer, unsigned cnt)
49 {
50 int rcode;
51 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
52 int old_bus = i2c_get_bus_num();
53
54 if (old_bus != CONFIG_I2C_ENV_EEPROM_BUS)
55 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS);
56 #endif
57
58 rcode = eeprom_write(dev_addr, offset, buffer, cnt);
59
60 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
61 i2c_set_bus_num(old_bus);
62 #endif
63
64 return rcode;
65 }
66
67 /** Call this function from overridden env_get_char_spec() if you need
68 * this functionality.
69 */
env_eeprom_get_char(int index)70 int env_eeprom_get_char(int index)
71 {
72 uchar c;
73 unsigned int off = CONFIG_ENV_OFFSET;
74
75 #ifdef CONFIG_ENV_OFFSET_REDUND
76 if (gd->env_valid == ENV_REDUND)
77 off = CONFIG_ENV_OFFSET_REDUND;
78 #endif
79 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
80 off + index + offsetof(env_t, data), &c, 1);
81
82 return c;
83 }
84
env_eeprom_load(void)85 static int env_eeprom_load(void)
86 {
87 char buf_env[CONFIG_ENV_SIZE];
88 unsigned int off = CONFIG_ENV_OFFSET;
89
90 #ifdef CONFIG_ENV_OFFSET_REDUND
91 ulong len, crc[2], crc_tmp;
92 unsigned int off_env[2];
93 uchar rdbuf[64], flags[2];
94 int i, crc_ok[2] = {0, 0};
95
96 eeprom_init(-1); /* prepare for EEPROM read/write */
97
98 off_env[0] = CONFIG_ENV_OFFSET;
99 off_env[1] = CONFIG_ENV_OFFSET_REDUND;
100
101 for (i = 0; i < 2; i++) {
102 /* read CRC */
103 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
104 off_env[i] + offsetof(env_t, crc),
105 (uchar *)&crc[i], sizeof(ulong));
106 /* read FLAGS */
107 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
108 off_env[i] + offsetof(env_t, flags),
109 (uchar *)&flags[i], sizeof(uchar));
110
111 crc_tmp = 0;
112 len = ENV_SIZE;
113 off = off_env[i] + offsetof(env_t, data);
114 while (len > 0) {
115 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
116
117 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR, off,
118 rdbuf, n);
119
120 crc_tmp = crc32(crc_tmp, rdbuf, n);
121 len -= n;
122 off += n;
123 }
124
125 if (crc_tmp == crc[i])
126 crc_ok[i] = 1;
127 }
128
129 if (!crc_ok[0] && !crc_ok[1]) {
130 gd->env_addr = 0;
131 gd->env_valid = ENV_INVALID;
132 } else if (crc_ok[0] && !crc_ok[1]) {
133 gd->env_valid = ENV_VALID;
134 } else if (!crc_ok[0] && crc_ok[1]) {
135 gd->env_valid = ENV_REDUND;
136 } else {
137 /* both ok - check serial */
138 if (flags[0] == ENV_REDUND_ACTIVE &&
139 flags[1] == ENV_REDUND_OBSOLETE)
140 gd->env_valid = ENV_VALID;
141 else if (flags[0] == ENV_REDUND_OBSOLETE &&
142 flags[1] == ENV_REDUND_ACTIVE)
143 gd->env_valid = ENV_REDUND;
144 else if (flags[0] == 0xFF && flags[1] == 0)
145 gd->env_valid = ENV_REDUND;
146 else if (flags[1] == 0xFF && flags[0] == 0)
147 gd->env_valid = ENV_VALID;
148 else /* flags are equal - almost impossible */
149 gd->env_valid = ENV_VALID;
150 }
151
152 #else /* CONFIG_ENV_OFFSET_REDUND */
153 ulong crc, len, new;
154 uchar rdbuf[64];
155
156 eeprom_init(-1); /* prepare for EEPROM read/write */
157
158 /* read old CRC */
159 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
160 CONFIG_ENV_OFFSET + offsetof(env_t, crc),
161 (uchar *)&crc, sizeof(ulong));
162
163 new = 0;
164 len = ENV_SIZE;
165 off = offsetof(env_t, data);
166 while (len > 0) {
167 int n = (len > sizeof(rdbuf)) ? sizeof(rdbuf) : len;
168
169 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
170 CONFIG_ENV_OFFSET + off, rdbuf, n);
171 new = crc32(new, rdbuf, n);
172 len -= n;
173 off += n;
174 }
175
176 if (crc == new) {
177 gd->env_valid = ENV_VALID;
178 } else {
179 gd->env_valid = ENV_INVALID;
180 }
181 #endif /* CONFIG_ENV_OFFSET_REDUND */
182
183 off = CONFIG_ENV_OFFSET;
184 #ifdef CONFIG_ENV_OFFSET_REDUND
185 if (gd->env_valid == ENV_REDUND)
186 off = CONFIG_ENV_OFFSET_REDUND;
187 #endif
188
189 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,
190 off, (uchar *)buf_env, CONFIG_ENV_SIZE);
191
192 return env_import(buf_env, 1, H_EXTERNAL);
193 }
194
env_eeprom_save(void)195 static int env_eeprom_save(void)
196 {
197 env_t env_new;
198 int rc;
199 unsigned int off = CONFIG_ENV_OFFSET;
200 #ifdef CONFIG_ENV_OFFSET_REDUND
201 unsigned int off_red = CONFIG_ENV_OFFSET_REDUND;
202 char flag_obsolete = ENV_REDUND_OBSOLETE;
203 #endif
204
205 rc = env_export(&env_new);
206 if (rc)
207 return rc;
208
209 #ifdef CONFIG_ENV_OFFSET_REDUND
210 if (gd->env_valid == ENV_VALID) {
211 off = CONFIG_ENV_OFFSET_REDUND;
212 off_red = CONFIG_ENV_OFFSET;
213 }
214
215 env_new.flags = ENV_REDUND_ACTIVE;
216 #endif
217
218 rc = eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
219 off, (uchar *)&env_new, CONFIG_ENV_SIZE);
220
221 #ifdef CONFIG_ENV_OFFSET_REDUND
222 if (rc == 0) {
223 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR,
224 off_red + offsetof(env_t, flags),
225 (uchar *)&flag_obsolete, 1);
226
227 if (gd->env_valid == ENV_VALID)
228 gd->env_valid = ENV_REDUND;
229 else
230 gd->env_valid = ENV_VALID;
231 }
232 #endif
233 return rc;
234 }
235
236 U_BOOT_ENV_LOCATION(eeprom) = {
237 .location = ENVL_EEPROM,
238 ENV_NAME("EEPROM")
239 .load = env_eeprom_load,
240 .save = env_save_ptr(env_eeprom_save),
241 };
242