1 // SPDX-License-Identifier: GPL-2.0+
3 * (C) Copyright 2000-2010
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
6 * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
7 * Andreas Heppel <aheppel@sysgo.de>
12 #include <environment.h>
13 #include <linux/stddef.h>
14 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
19 #include <linux/compiler.h> /* for BUG_ON */
21 DECLARE_GLOBAL_DATA_PTR
;
23 static int eeprom_bus_read(unsigned dev_addr
, unsigned offset
,
24 uchar
*buffer
, unsigned cnt
)
27 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
28 int old_bus
= i2c_get_bus_num();
30 if (old_bus
!= CONFIG_I2C_ENV_EEPROM_BUS
)
31 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS
);
34 rcode
= eeprom_read(dev_addr
, offset
, buffer
, cnt
);
36 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
37 i2c_set_bus_num(old_bus
);
43 static int eeprom_bus_write(unsigned dev_addr
, unsigned offset
,
44 uchar
*buffer
, unsigned cnt
)
47 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
48 int old_bus
= i2c_get_bus_num();
50 if (old_bus
!= CONFIG_I2C_ENV_EEPROM_BUS
)
51 i2c_set_bus_num(CONFIG_I2C_ENV_EEPROM_BUS
);
54 rcode
= eeprom_write(dev_addr
, offset
, buffer
, cnt
);
56 #if defined(CONFIG_I2C_ENV_EEPROM_BUS)
57 i2c_set_bus_num(old_bus
);
63 /** Call this function from overridden env_get_char_spec() if you need
66 int env_eeprom_get_char(int index
)
69 unsigned int off
= CONFIG_ENV_OFFSET
;
71 #ifdef CONFIG_ENV_OFFSET_REDUND
72 if (gd
->env_valid
== ENV_REDUND
)
73 off
= CONFIG_ENV_OFFSET_REDUND
;
75 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR
,
76 off
+ index
+ offsetof(env_t
, data
), &c
, 1);
81 static int env_eeprom_load(void)
83 char buf_env
[CONFIG_ENV_SIZE
];
84 unsigned int off
= CONFIG_ENV_OFFSET
;
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};
92 eeprom_init(-1); /* prepare for EEPROM read/write */
94 off_env
[0] = CONFIG_ENV_OFFSET
;
95 off_env
[1] = CONFIG_ENV_OFFSET_REDUND
;
97 for (i
= 0; i
< 2; i
++) {
99 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR
,
100 off_env
[i
] + offsetof(env_t
, crc
),
101 (uchar
*)&crc
[i
], sizeof(ulong
));
103 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR
,
104 off_env
[i
] + offsetof(env_t
, flags
),
105 (uchar
*)&flags
[i
], sizeof(uchar
));
109 off
= off_env
[i
] + offsetof(env_t
, data
);
111 int n
= (len
> sizeof(rdbuf
)) ? sizeof(rdbuf
) : len
;
113 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR
, off
,
116 crc_tmp
= crc32(crc_tmp
, rdbuf
, n
);
121 if (crc_tmp
== crc
[i
])
125 if (!crc_ok
[0] && !crc_ok
[1]) {
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
;
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
;
146 #else /* CONFIG_ENV_OFFSET_REDUND */
150 eeprom_init(-1); /* prepare for EEPROM read/write */
153 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR
,
154 CONFIG_ENV_OFFSET
+ offsetof(env_t
, crc
),
155 (uchar
*)&crc
, sizeof(ulong
));
159 off
= offsetof(env_t
, data
);
161 int n
= (len
> sizeof(rdbuf
)) ? sizeof(rdbuf
) : len
;
163 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR
,
164 CONFIG_ENV_OFFSET
+ off
, rdbuf
, n
);
165 new = crc32(new, rdbuf
, n
);
171 gd
->env_valid
= ENV_VALID
;
173 gd
->env_valid
= ENV_INVALID
;
175 #endif /* CONFIG_ENV_OFFSET_REDUND */
177 off
= CONFIG_ENV_OFFSET
;
178 #ifdef CONFIG_ENV_OFFSET_REDUND
179 if (gd
->env_valid
== ENV_REDUND
)
180 off
= CONFIG_ENV_OFFSET_REDUND
;
183 eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR
,
184 off
, (uchar
*)buf_env
, CONFIG_ENV_SIZE
);
186 return env_import(buf_env
, 1);
189 static int env_eeprom_save(void)
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
;
199 rc
= env_export(&env_new
);
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
;
209 env_new
.flags
= ACTIVE_FLAG
;
212 rc
= eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR
,
213 off
, (uchar
*)&env_new
, CONFIG_ENV_SIZE
);
215 #ifdef CONFIG_ENV_OFFSET_REDUND
217 eeprom_bus_write(CONFIG_SYS_DEF_EEPROM_ADDR
,
218 off_red
+ offsetof(env_t
, flags
),
219 (uchar
*)&flag_obsolete
, 1);
221 if (gd
->env_valid
== ENV_VALID
)
222 gd
->env_valid
= ENV_REDUND
;
224 gd
->env_valid
= ENV_VALID
;
230 U_BOOT_ENV_LOCATION(eeprom
) = {
231 .location
= ENVL_EEPROM
,
233 .load
= env_eeprom_load
,
234 .save
= env_save_ptr(env_eeprom_save
),