1 /* Three-wire (MicroWire) serial eeprom driver (for 93C46 and compatibles) */
5 #ifdef CONFIG_MW_EEPROM
10 * Serial EEPROM opcodes, including start bit
12 #define EEP_OPC_ERASE 0x7 /* 3-bit opcode */
13 #define EEP_OPC_WRITE 0x5 /* 3-bit opcode */
14 #define EEP_OPC_READ 0x6 /* 3-bit opcode */
16 #define EEP_OPC_ERASE_ALL 0x12 /* 5-bit opcode */
17 #define EEP_OPC_ERASE_EN 0x13 /* 5-bit opcode */
18 #define EEP_OPC_WRITE_ALL 0x11 /* 5-bit opcode */
19 #define EEP_OPC_ERASE_DIS 0x10 /* 5-bit opcode */
23 static void mw_eeprom_select(int dev
)
25 ssi_set_interface(2048, 0, 0, 0);
32 static int mw_eeprom_size(int dev
)
37 mw_eeprom_select(dev
);
38 ssi_tx_byte(EEP_OPC_READ
);
40 res
= ssi_txrx_byte(0) << 8;
42 for (x
= 0; x
< 16; x
++) {
43 if (! (res
& 0x8000)) {
53 int mw_eeprom_erase_enable(int dev
)
55 mw_eeprom_select(dev
);
56 ssi_tx_byte(EEP_OPC_ERASE_EN
);
64 int mw_eeprom_erase_disable(int dev
)
66 mw_eeprom_select(dev
);
67 ssi_tx_byte(EEP_OPC_ERASE_DIS
);
76 u32
mw_eeprom_read_word(int dev
, int addr
)
82 mw_eeprom_select(dev
);
83 ssi_tx_byte((EEP_OPC_READ
<< 5) | ((addr
>> (addrlen
- 5)) & 0x1f));
84 rcv
= ssi_txrx_byte(addr
<< (13 - addrlen
));
85 res
= rcv
<< (16 - addrlen
);
91 res
|= rcv
<< (bits
- 8);
93 res
|= rcv
>> (8 - bits
);
103 int mw_eeprom_write_word(int dev
, int addr
, u16 data
)
108 mw_eeprom_erase_enable(dev
);
109 mw_eeprom_select(dev
);
113 byte1
= EEP_OPC_WRITE
>> 2;
114 byte2
= (EEP_OPC_WRITE
<< 6)&0xc0;
118 byte1
= EEP_OPC_WRITE
>> 1;
119 byte2
= (EEP_OPC_WRITE
<< 7)&0x80;
123 byte1
= EEP_OPC_WRITE
;
127 byte1
= EEP_OPC_WRITE
<< 1;
132 byte1
= EEP_OPC_WRITE
<< 2;
137 printf("Unsupported number of address bits: %d\n", addrlen
);
144 ssi_tx_byte(data
>> 8);
145 ssi_tx_byte(data
& 0xff);
147 udelay(10000); /* Worst case */
148 mw_eeprom_erase_disable(dev
);
154 int mw_eeprom_write(int dev
, int addr
, u8
*buffer
, int len
)
160 u16 temp
= mw_eeprom_read_word(dev
, addr
>> 1);
164 mw_eeprom_write_word(dev
, addr
>> 1, temp
);
172 mw_eeprom_write_word(dev
, addr
>> 1, *(u16
*)buffer
);
180 u16 temp
= mw_eeprom_read_word(dev
, addr
>> 1);
182 temp
|= buffer
[0] << 8;
184 mw_eeprom_write_word(dev
, addr
>> 1, temp
);
195 int mw_eeprom_read(int dev
, int addr
, u8
*buffer
, int len
)
201 u16 temp
= mw_eeprom_read_word(dev
, addr
>> 1);
202 buffer
[0]= temp
& 0xff;
211 *(u16
*)buffer
= mw_eeprom_read_word(dev
, addr
>> 1);
219 u16 temp
= mw_eeprom_read_word(dev
, addr
>> 1);
220 buffer
[0] = temp
>> 8;
231 int mw_eeprom_probe(int dev
)
233 addrlen
= mw_eeprom_size(dev
);
235 if (addrlen
< 6 || addrlen
> 10) {