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
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* w1_ds2430.c - w1 family 14 (DS2430) driver
**
* Copyright (c) 2019 Angelo Dureghello <angelo.dureghello@timesys.com>
*
* Cloned and modified from ds2431
* Copyright (c) 2008 Bernhard Weirich <bernhard.weirich@riedel.net>
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/w1.h>
#define W1_EEPROM_DS2430 0x14
#define W1_F14_EEPROM_SIZE 32
#define W1_F14_PAGE_COUNT 1
#define W1_F14_PAGE_BITS 5
#define W1_F14_PAGE_SIZE (1 << W1_F14_PAGE_BITS)
#define W1_F14_PAGE_MASK 0x1F
#define W1_F14_SCRATCH_BITS 5
#define W1_F14_SCRATCH_SIZE (1 << W1_F14_SCRATCH_BITS)
#define W1_F14_SCRATCH_MASK (W1_F14_SCRATCH_SIZE-1)
#define W1_F14_READ_EEPROM 0xF0
#define W1_F14_WRITE_SCRATCH 0x0F
#define W1_F14_READ_SCRATCH 0xAA
#define W1_F14_COPY_SCRATCH 0x55
#define W1_F14_VALIDATION_KEY 0xa5
#define W1_F14_TPROG_MS 11
#define W1_F14_READ_RETRIES 10
#define W1_F14_READ_MAXLEN W1_F14_SCRATCH_SIZE
/*
* Check the file size bounds and adjusts count as needed.
* This would not be needed if the file size didn't reset to 0 after a write.
*/
static inline size_t w1_f14_fix_count(loff_t off, size_t count, size_t size)
{
if (off > size)
return 0;
if ((off + count) > size)
return size - off;
return count;
}
/*
* Read a block from W1 ROM two times and compares the results.
* If they are equal they are returned, otherwise the read
* is repeated W1_F14_READ_RETRIES times.
*
* count must not exceed W1_F14_READ_MAXLEN.
*/
static int w1_f14_readblock(struct w1_slave *sl, int off, int count, char *buf)
{
u8 wrbuf[2];
u8 cmp[W1_F14_READ_MAXLEN];
int tries = W1_F14_READ_RETRIES;
do {
wrbuf[0] = W1_F14_READ_EEPROM;
wrbuf[1] = off & 0xff;
if (w1_reset_select_slave(sl))
return -1;
w1_write_block(sl->master, wrbuf, 2);
w1_read_block(sl->master, buf, count);
if (w1_reset_select_slave(sl))
return -1;
w1_write_block(sl->master, wrbuf, 2);
w1_read_block(sl->master, cmp, count);
if (!memcmp(cmp, buf, count))
return 0;
} while (--tries);
dev_err(&sl->dev, "proof reading failed %d times\n",
W1_F14_READ_RETRIES);
return -1;
}
static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
int todo = count;
count = w1_f14_fix_count(off, count, W1_F14_EEPROM_SIZE);
if (count == 0)
return 0;
mutex_lock(&sl->master->bus_mutex);
/* read directly from the EEPROM in chunks of W1_F14_READ_MAXLEN */
while (todo > 0) {
int block_read;
if (todo >= W1_F14_READ_MAXLEN)
block_read = W1_F14_READ_MAXLEN;
else
block_read = todo;
if (w1_f14_readblock(sl, off, block_read, buf) < 0)
count = -EIO;
todo -= W1_F14_READ_MAXLEN;
buf += W1_F14_READ_MAXLEN;
off += W1_F14_READ_MAXLEN;
}
mutex_unlock(&sl->master->bus_mutex);
return count;
}
/*
* Writes to the scratchpad and reads it back for verification.
* Then copies the scratchpad to EEPROM.
* The data must be aligned at W1_F14_SCRATCH_SIZE bytes and
* must be W1_F14_SCRATCH_SIZE bytes long.
* The master must be locked.
*
* @param sl The slave structure
* @param addr Address for the write
* @param len length must be <= (W1_F14_PAGE_SIZE - (addr & W1_F14_PAGE_MASK))
* @param data The data to write
* @return 0=Success -1=failure
*/
static int w1_f14_write(struct w1_slave *sl, int addr, int len, const u8 *data)
{
int tries = W1_F14_READ_RETRIES;
u8 wrbuf[2];
u8 rdbuf[W1_F14_SCRATCH_SIZE + 3];
retry:
/* Write the data to the scratchpad */
if (w1_reset_select_slave(sl))
return -1;
wrbuf[0] = W1_F14_WRITE_SCRATCH;
wrbuf[1] = addr & 0xff;
w1_write_block(sl->master, wrbuf, 2);
w1_write_block(sl->master, data, len);
/* Read the scratchpad and verify */
if (w1_reset_select_slave(sl))
return -1;
w1_write_8(sl->master, W1_F14_READ_SCRATCH);
w1_read_block(sl->master, rdbuf, len + 2);
/*
* Compare what was read against the data written
* Note: on read scratchpad, device returns 2 bulk 0xff bytes,
* to be discarded.
*/
if ((memcmp(data, &rdbuf[2], len) != 0)) {
if (--tries)
goto retry;
dev_err(&sl->dev,
"could not write to eeprom, scratchpad compare failed %d times\n",
W1_F14_READ_RETRIES);
return -1;
}
/* Copy the scratchpad to EEPROM */
if (w1_reset_select_slave(sl))
return -1;
wrbuf[0] = W1_F14_COPY_SCRATCH;
wrbuf[1] = W1_F14_VALIDATION_KEY;
w1_write_block(sl->master, wrbuf, 2);
/* Sleep for tprog ms to wait for the write to complete */
msleep(W1_F14_TPROG_MS);
/* Reset the bus to wake up the EEPROM */
w1_reset_bus(sl->master);
return 0;
}
static ssize_t eeprom_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
{
struct w1_slave *sl = kobj_to_w1_slave(kobj);
int addr, len;
int copy;
count = w1_f14_fix_count(off, count, W1_F14_EEPROM_SIZE);
if (count == 0)
return 0;
mutex_lock(&sl->master->bus_mutex);
/* Can only write data in blocks of the size of the scratchpad */
addr = off;
len = count;
while (len > 0) {
/* if len too short or addr not aligned */
if (len < W1_F14_SCRATCH_SIZE || addr & W1_F14_SCRATCH_MASK) {
char tmp[W1_F14_SCRATCH_SIZE];
/* read the block and update the parts to be written */
if (w1_f14_readblock(sl, addr & ~W1_F14_SCRATCH_MASK,
W1_F14_SCRATCH_SIZE, tmp)) {
count = -EIO;
goto out_up;
}
/* copy at most to the boundary of the PAGE or len */
copy = W1_F14_SCRATCH_SIZE -
(addr & W1_F14_SCRATCH_MASK);
if (copy > len)
copy = len;
memcpy(&tmp[addr & W1_F14_SCRATCH_MASK], buf, copy);
if (w1_f14_write(sl, addr & ~W1_F14_SCRATCH_MASK,
W1_F14_SCRATCH_SIZE, tmp) < 0) {
count = -EIO;
goto out_up;
}
} else {
copy = W1_F14_SCRATCH_SIZE;
if (w1_f14_write(sl, addr, copy, buf) < 0) {
count = -EIO;
goto out_up;
}
}
buf += copy;
addr += copy;
len -= copy;
}
out_up:
mutex_unlock(&sl->master->bus_mutex);
return count;
}
static BIN_ATTR_RW(eeprom, W1_F14_EEPROM_SIZE);
static struct bin_attribute *w1_f14_bin_attrs[] = {
&bin_attr_eeprom,
NULL,
};
static const struct attribute_group w1_f14_group = {
.bin_attrs = w1_f14_bin_attrs,
};
static const struct attribute_group *w1_f14_groups[] = {
&w1_f14_group,
NULL,
};
static struct w1_family_ops w1_f14_fops = {
.groups = w1_f14_groups,
};
static struct w1_family w1_family_14 = {
.fid = W1_EEPROM_DS2430,
.fops = &w1_f14_fops,
};
module_w1_family(w1_family_14);
MODULE_AUTHOR("Angelo Dureghello <angelo.dureghello@timesys.com>");
MODULE_DESCRIPTION("w1 family 14 driver for DS2430, 256kb EEPROM");
MODULE_LICENSE("GPL");
MODULE_ALIAS("w1-family-" __stringify(W1_EEPROM_DS2430));
|
