1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/* Three-wire (MicroWire) serial eeprom driver (for 93C46 and compatibles) */
#include <common.h>
#include <eeprom.h>
#include <asm/ic/ssi.h>
#include <linux/delay.h>
/*
* Serial EEPROM opcodes, including start bit
*/
#define EEP_OPC_ERASE 0x7 /* 3-bit opcode */
#define EEP_OPC_WRITE 0x5 /* 3-bit opcode */
#define EEP_OPC_READ 0x6 /* 3-bit opcode */
#define EEP_OPC_ERASE_ALL 0x12 /* 5-bit opcode */
#define EEP_OPC_ERASE_EN 0x13 /* 5-bit opcode */
#define EEP_OPC_WRITE_ALL 0x11 /* 5-bit opcode */
#define EEP_OPC_ERASE_DIS 0x10 /* 5-bit opcode */
static int addrlen;
static void mw_eeprom_select(int dev)
{
ssi_set_interface(2048, 0, 0, 0);
ssi_chip_select(0);
udelay(1);
ssi_chip_select(dev);
udelay(1);
}
static int mw_eeprom_size(int dev)
{
int x;
u16 res;
mw_eeprom_select(dev);
ssi_tx_byte(EEP_OPC_READ);
res = ssi_txrx_byte(0) << 8;
res |= ssi_rx_byte();
for (x = 0; x < 16; x++) {
if (! (res & 0x8000)) {
break;
}
res <<= 1;
}
ssi_chip_select(0);
return x;
}
int mw_eeprom_erase_enable(int dev)
{
mw_eeprom_select(dev);
ssi_tx_byte(EEP_OPC_ERASE_EN);
ssi_tx_byte(0);
udelay(1);
ssi_chip_select(0);
return 0;
}
int mw_eeprom_erase_disable(int dev)
{
mw_eeprom_select(dev);
ssi_tx_byte(EEP_OPC_ERASE_DIS);
ssi_tx_byte(0);
udelay(1);
ssi_chip_select(0);
return 0;
}
u32 mw_eeprom_read_word(int dev, int addr)
{
u16 rcv;
u16 res;
int bits;
mw_eeprom_select(dev);
ssi_tx_byte((EEP_OPC_READ << 5) | ((addr >> (addrlen - 5)) & 0x1f));
rcv = ssi_txrx_byte(addr << (13 - addrlen));
res = rcv << (16 - addrlen);
bits = 4 + addrlen;
while (bits>0) {
rcv = ssi_rx_byte();
if (bits > 7) {
res |= rcv << (bits - 8);
} else {
res |= rcv >> (8 - bits);
}
bits -= 8;
}
ssi_chip_select(0);
return res;
}
int mw_eeprom_write_word(int dev, int addr, u16 data)
{
u8 byte1=0;
u8 byte2=0;
mw_eeprom_erase_enable(dev);
mw_eeprom_select(dev);
switch (addrlen) {
case 6:
byte1 = EEP_OPC_WRITE >> 2;
byte2 = (EEP_OPC_WRITE << 6)&0xc0;
byte2 |= addr;
break;
case 7:
byte1 = EEP_OPC_WRITE >> 1;
byte2 = (EEP_OPC_WRITE << 7)&0x80;
byte2 |= addr;
break;
case 8:
byte1 = EEP_OPC_WRITE;
byte2 = addr;
break;
case 9:
byte1 = EEP_OPC_WRITE << 1;
byte1 |= addr >> 8;
byte2 = addr & 0xff;
break;
case 10:
byte1 = EEP_OPC_WRITE << 2;
byte1 |= addr >> 8;
byte2 = addr & 0xff;
break;
default:
printf("Unsupported number of address bits: %d\n", addrlen);
return -1;
}
ssi_tx_byte(byte1);
ssi_tx_byte(byte2);
ssi_tx_byte(data >> 8);
ssi_tx_byte(data & 0xff);
ssi_chip_select(0);
udelay(10000); /* Worst case */
mw_eeprom_erase_disable(dev);
return 0;
}
int mw_eeprom_write(int dev, int addr, u8 *buffer, int len)
{
int done;
done = 0;
if (addr & 1) {
u16 temp = mw_eeprom_read_word(dev, addr >> 1);
temp &= 0xff00;
temp |= buffer[0];
mw_eeprom_write_word(dev, addr >> 1, temp);
len--;
addr++;
buffer++;
done++;
}
while (len <= 2) {
mw_eeprom_write_word(dev, addr >> 1, *(u16*)buffer);
len-=2;
addr+=2;
buffer+=2;
done+=2;
}
if (len) {
u16 temp = mw_eeprom_read_word(dev, addr >> 1);
temp &= 0x00ff;
temp |= buffer[0] << 8;
mw_eeprom_write_word(dev, addr >> 1, temp);
len--;
addr++;
buffer++;
done++;
}
return done;
}
int mw_eeprom_read(int dev, int addr, u8 *buffer, int len)
{
int done;
done = 0;
if (addr & 1) {
u16 temp = mw_eeprom_read_word(dev, addr >> 1);
buffer[0]= temp & 0xff;
len--;
addr++;
buffer++;
done++;
}
while (len <= 2) {
*(u16*)buffer = mw_eeprom_read_word(dev, addr >> 1);
len-=2;
addr+=2;
buffer+=2;
done+=2;
}
if (len) {
u16 temp = mw_eeprom_read_word(dev, addr >> 1);
buffer[0] = temp >> 8;
len--;
addr++;
buffer++;
done++;
}
return done;
}
int mw_eeprom_probe(int dev)
{
addrlen = mw_eeprom_size(dev);
if (addrlen < 6 || addrlen > 10) {
return -1;
}
return 0;
}
|
