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80895392 EP |
1 | /* |
2 | * w1_ds2433.c - w1 family 23 (DS2433) driver | |
3 | * | |
4 | * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com> | |
5 | * | |
0a25e4d5 EP |
6 | * This source code is licensed under the GNU General Public License, |
7 | * Version 2. See the file COPYING for more details. | |
80895392 EP |
8 | */ |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/moduleparam.h> | |
13 | #include <linux/device.h> | |
14 | #include <linux/types.h> | |
15 | #include <linux/delay.h> | |
e9d55f9d | 16 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
0a25e4d5 | 17 | #include <linux/crc16.h> |
f24ec7f6 EP |
18 | |
19 | #define CRC16_INIT 0 | |
20 | #define CRC16_VALID 0xb001 | |
21 | ||
0a25e4d5 | 22 | #endif |
80895392 | 23 | |
bd529cfb | 24 | #include "../w1.h" |
bd529cfb EP |
25 | #include "../w1_int.h" |
26 | #include "../w1_family.h" | |
80895392 EP |
27 | |
28 | MODULE_LICENSE("GPL"); | |
29 | MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>"); | |
30 | MODULE_DESCRIPTION("w1 family 23 driver for DS2433, 4kb EEPROM"); | |
31 | ||
32 | #define W1_EEPROM_SIZE 512 | |
0a25e4d5 | 33 | #define W1_PAGE_COUNT 16 |
80895392 EP |
34 | #define W1_PAGE_SIZE 32 |
35 | #define W1_PAGE_BITS 5 | |
36 | #define W1_PAGE_MASK 0x1F | |
37 | ||
0a25e4d5 EP |
38 | #define W1_F23_TIME 300 |
39 | ||
80895392 EP |
40 | #define W1_F23_READ_EEPROM 0xF0 |
41 | #define W1_F23_WRITE_SCRATCH 0x0F | |
42 | #define W1_F23_READ_SCRATCH 0xAA | |
43 | #define W1_F23_COPY_SCRATCH 0x55 | |
44 | ||
0a25e4d5 EP |
45 | struct w1_f23_data { |
46 | u8 memory[W1_EEPROM_SIZE]; | |
47 | u32 validcrc; | |
48 | }; | |
49 | ||
80895392 EP |
50 | /** |
51 | * Check the file size bounds and adjusts count as needed. | |
0a25e4d5 | 52 | * This would not be needed if the file size didn't reset to 0 after a write. |
80895392 EP |
53 | */ |
54 | static inline size_t w1_f23_fix_count(loff_t off, size_t count, size_t size) | |
55 | { | |
56 | if (off > size) | |
57 | return 0; | |
58 | ||
59 | if ((off + count) > size) | |
60 | return (size - off); | |
61 | ||
62 | return count; | |
63 | } | |
64 | ||
e9d55f9d | 65 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
0a25e4d5 EP |
66 | static int w1_f23_refresh_block(struct w1_slave *sl, struct w1_f23_data *data, |
67 | int block) | |
68 | { | |
69 | u8 wrbuf[3]; | |
70 | int off = block * W1_PAGE_SIZE; | |
71 | ||
72 | if (data->validcrc & (1 << block)) | |
73 | return 0; | |
74 | ||
75 | if (w1_reset_select_slave(sl)) { | |
76 | data->validcrc = 0; | |
77 | return -EIO; | |
78 | } | |
79 | ||
80 | wrbuf[0] = W1_F23_READ_EEPROM; | |
81 | wrbuf[1] = off & 0xff; | |
82 | wrbuf[2] = off >> 8; | |
83 | w1_write_block(sl->master, wrbuf, 3); | |
84 | w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE); | |
85 | ||
86 | /* cache the block if the CRC is valid */ | |
87 | if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID) | |
88 | data->validcrc |= (1 << block); | |
89 | ||
90 | return 0; | |
91 | } | |
e9d55f9d | 92 | #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ |
0a25e4d5 | 93 | |
91a69029 ZR |
94 | static ssize_t w1_f23_read_bin(struct kobject *kobj, |
95 | struct bin_attribute *bin_attr, | |
96 | char *buf, loff_t off, size_t count) | |
80895392 EP |
97 | { |
98 | struct w1_slave *sl = kobj_to_w1_slave(kobj); | |
e9d55f9d | 99 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
0a25e4d5 EP |
100 | struct w1_f23_data *data = sl->family_data; |
101 | int i, min_page, max_page; | |
102 | #else | |
80895392 | 103 | u8 wrbuf[3]; |
0a25e4d5 | 104 | #endif |
80895392 EP |
105 | |
106 | if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0) | |
107 | return 0; | |
108 | ||
abd52a13 | 109 | mutex_lock(&sl->master->mutex); |
80895392 | 110 | |
e9d55f9d | 111 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
0a25e4d5 EP |
112 | |
113 | min_page = (off >> W1_PAGE_BITS); | |
114 | max_page = (off + count - 1) >> W1_PAGE_BITS; | |
115 | for (i = min_page; i <= max_page; i++) { | |
116 | if (w1_f23_refresh_block(sl, data, i)) { | |
117 | count = -EIO; | |
118 | goto out_up; | |
119 | } | |
120 | } | |
121 | memcpy(buf, &data->memory[off], count); | |
122 | ||
e9d55f9d | 123 | #else /* CONFIG_W1_SLAVE_DS2433_CRC */ |
0a25e4d5 | 124 | |
80895392 EP |
125 | /* read directly from the EEPROM */ |
126 | if (w1_reset_select_slave(sl)) { | |
127 | count = -EIO; | |
128 | goto out_up; | |
129 | } | |
130 | ||
131 | wrbuf[0] = W1_F23_READ_EEPROM; | |
132 | wrbuf[1] = off & 0xff; | |
133 | wrbuf[2] = off >> 8; | |
134 | w1_write_block(sl->master, wrbuf, 3); | |
135 | w1_read_block(sl->master, buf, count); | |
136 | ||
e9d55f9d | 137 | #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ |
0a25e4d5 | 138 | |
80895392 | 139 | out_up: |
abd52a13 | 140 | mutex_unlock(&sl->master->mutex); |
80895392 EP |
141 | |
142 | return count; | |
143 | } | |
144 | ||
145 | /** | |
146 | * Writes to the scratchpad and reads it back for verification. | |
0a25e4d5 EP |
147 | * Then copies the scratchpad to EEPROM. |
148 | * The data must be on one page. | |
80895392 EP |
149 | * The master must be locked. |
150 | * | |
151 | * @param sl The slave structure | |
152 | * @param addr Address for the write | |
153 | * @param len length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK)) | |
154 | * @param data The data to write | |
155 | * @return 0=Success -1=failure | |
156 | */ | |
157 | static int w1_f23_write(struct w1_slave *sl, int addr, int len, const u8 *data) | |
158 | { | |
dca17146 BG |
159 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
160 | struct w1_f23_data *f23 = sl->family_data; | |
161 | #endif | |
80895392 EP |
162 | u8 wrbuf[4]; |
163 | u8 rdbuf[W1_PAGE_SIZE + 3]; | |
164 | u8 es = (addr + len - 1) & 0x1f; | |
165 | ||
166 | /* Write the data to the scratchpad */ | |
167 | if (w1_reset_select_slave(sl)) | |
168 | return -1; | |
169 | ||
170 | wrbuf[0] = W1_F23_WRITE_SCRATCH; | |
171 | wrbuf[1] = addr & 0xff; | |
172 | wrbuf[2] = addr >> 8; | |
173 | ||
174 | w1_write_block(sl->master, wrbuf, 3); | |
175 | w1_write_block(sl->master, data, len); | |
176 | ||
177 | /* Read the scratchpad and verify */ | |
178 | if (w1_reset_select_slave(sl)) | |
179 | return -1; | |
180 | ||
181 | w1_write_8(sl->master, W1_F23_READ_SCRATCH); | |
182 | w1_read_block(sl->master, rdbuf, len + 3); | |
183 | ||
184 | /* Compare what was read against the data written */ | |
185 | if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) || | |
186 | (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0)) | |
187 | return -1; | |
188 | ||
189 | /* Copy the scratchpad to EEPROM */ | |
190 | if (w1_reset_select_slave(sl)) | |
191 | return -1; | |
192 | ||
193 | wrbuf[0] = W1_F23_COPY_SCRATCH; | |
194 | wrbuf[3] = es; | |
195 | w1_write_block(sl->master, wrbuf, 4); | |
196 | ||
197 | /* Sleep for 5 ms to wait for the write to complete */ | |
198 | msleep(5); | |
199 | ||
200 | /* Reset the bus to wake up the EEPROM (this may not be needed) */ | |
201 | w1_reset_bus(sl->master); | |
dca17146 BG |
202 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
203 | f23->validcrc &= ~(1 << (addr >> W1_PAGE_BITS)); | |
204 | #endif | |
80895392 EP |
205 | return 0; |
206 | } | |
207 | ||
91a69029 ZR |
208 | static ssize_t w1_f23_write_bin(struct kobject *kobj, |
209 | struct bin_attribute *bin_attr, | |
210 | char *buf, loff_t off, size_t count) | |
80895392 EP |
211 | { |
212 | struct w1_slave *sl = kobj_to_w1_slave(kobj); | |
213 | int addr, len, idx; | |
214 | ||
215 | if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0) | |
216 | return 0; | |
217 | ||
e9d55f9d | 218 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
0a25e4d5 EP |
219 | /* can only write full blocks in cached mode */ |
220 | if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) { | |
f24ec7f6 | 221 | dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n", |
0a25e4d5 EP |
222 | (int)off, count); |
223 | return -EINVAL; | |
224 | } | |
225 | ||
226 | /* make sure the block CRCs are valid */ | |
227 | for (idx = 0; idx < count; idx += W1_PAGE_SIZE) { | |
228 | if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE) != CRC16_VALID) { | |
229 | dev_err(&sl->dev, "bad CRC at offset %d\n", (int)off); | |
230 | return -EINVAL; | |
231 | } | |
232 | } | |
e9d55f9d | 233 | #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ |
0a25e4d5 | 234 | |
abd52a13 | 235 | mutex_lock(&sl->master->mutex); |
80895392 EP |
236 | |
237 | /* Can only write data to one page at a time */ | |
238 | idx = 0; | |
239 | while (idx < count) { | |
240 | addr = off + idx; | |
241 | len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK); | |
242 | if (len > (count - idx)) | |
243 | len = count - idx; | |
244 | ||
245 | if (w1_f23_write(sl, addr, len, &buf[idx]) < 0) { | |
246 | count = -EIO; | |
247 | goto out_up; | |
248 | } | |
249 | idx += len; | |
250 | } | |
251 | ||
252 | out_up: | |
abd52a13 | 253 | mutex_unlock(&sl->master->mutex); |
80895392 EP |
254 | |
255 | return count; | |
256 | } | |
257 | ||
258 | static struct bin_attribute w1_f23_bin_attr = { | |
259 | .attr = { | |
260 | .name = "eeprom", | |
261 | .mode = S_IRUGO | S_IWUSR, | |
80895392 EP |
262 | }, |
263 | .size = W1_EEPROM_SIZE, | |
264 | .read = w1_f23_read_bin, | |
265 | .write = w1_f23_write_bin, | |
266 | }; | |
267 | ||
268 | static int w1_f23_add_slave(struct w1_slave *sl) | |
269 | { | |
0a25e4d5 | 270 | int err; |
e9d55f9d | 271 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
0a25e4d5 EP |
272 | struct w1_f23_data *data; |
273 | ||
dd00cc48 | 274 | data = kzalloc(sizeof(struct w1_f23_data), GFP_KERNEL); |
0a25e4d5 EP |
275 | if (!data) |
276 | return -ENOMEM; | |
0a25e4d5 EP |
277 | sl->family_data = data; |
278 | ||
e9d55f9d | 279 | #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ |
0a25e4d5 EP |
280 | |
281 | err = sysfs_create_bin_file(&sl->dev.kobj, &w1_f23_bin_attr); | |
282 | ||
e9d55f9d | 283 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
0a25e4d5 EP |
284 | if (err) |
285 | kfree(data); | |
e9d55f9d | 286 | #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ |
0a25e4d5 EP |
287 | |
288 | return err; | |
80895392 EP |
289 | } |
290 | ||
291 | static void w1_f23_remove_slave(struct w1_slave *sl) | |
292 | { | |
e9d55f9d | 293 | #ifdef CONFIG_W1_SLAVE_DS2433_CRC |
6044ec88 JJ |
294 | kfree(sl->family_data); |
295 | sl->family_data = NULL; | |
e9d55f9d | 296 | #endif /* CONFIG_W1_SLAVE_DS2433_CRC */ |
80895392 EP |
297 | sysfs_remove_bin_file(&sl->dev.kobj, &w1_f23_bin_attr); |
298 | } | |
299 | ||
300 | static struct w1_family_ops w1_f23_fops = { | |
301 | .add_slave = w1_f23_add_slave, | |
302 | .remove_slave = w1_f23_remove_slave, | |
303 | }; | |
304 | ||
305 | static struct w1_family w1_family_23 = { | |
306 | .fid = W1_EEPROM_DS2433, | |
307 | .fops = &w1_f23_fops, | |
308 | }; | |
309 | ||
310 | static int __init w1_f23_init(void) | |
311 | { | |
312 | return w1_register_family(&w1_family_23); | |
313 | } | |
314 | ||
315 | static void __exit w1_f23_fini(void) | |
316 | { | |
317 | w1_unregister_family(&w1_family_23); | |
318 | } | |
319 | ||
320 | module_init(w1_f23_init); | |
321 | module_exit(w1_f23_fini); |