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89610274 JFD |
1 | /* |
2 | * w1_ds2408.c - w1 family 29 (DS2408) driver | |
3 | * | |
4 | * Copyright (c) 2010 Jean-Francois Dagenais <dagenaisj@sonatest.com> | |
5 | * | |
6 | * This source code is licensed under the GNU General Public License, | |
7 | * Version 2. See the file COPYING for more details. | |
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> | |
16 | #include <linux/slab.h> | |
17 | ||
18 | #include "../w1.h" | |
19 | #include "../w1_int.h" | |
20 | #include "../w1_family.h" | |
21 | ||
22 | MODULE_LICENSE("GPL"); | |
23 | MODULE_AUTHOR("Jean-Francois Dagenais <dagenaisj@sonatest.com>"); | |
24 | MODULE_DESCRIPTION("w1 family 29 driver for DS2408 8 Pin IO"); | |
8d7bda51 | 25 | MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2408)); |
89610274 JFD |
26 | |
27 | ||
28 | #define W1_F29_RETRIES 3 | |
29 | ||
30 | #define W1_F29_REG_LOGIG_STATE 0x88 /* R */ | |
31 | #define W1_F29_REG_OUTPUT_LATCH_STATE 0x89 /* R */ | |
32 | #define W1_F29_REG_ACTIVITY_LATCH_STATE 0x8A /* R */ | |
33 | #define W1_F29_REG_COND_SEARCH_SELECT_MASK 0x8B /* RW */ | |
34 | #define W1_F29_REG_COND_SEARCH_POL_SELECT 0x8C /* RW */ | |
35 | #define W1_F29_REG_CONTROL_AND_STATUS 0x8D /* RW */ | |
36 | ||
37 | #define W1_F29_FUNC_READ_PIO_REGS 0xF0 | |
38 | #define W1_F29_FUNC_CHANN_ACCESS_READ 0xF5 | |
39 | #define W1_F29_FUNC_CHANN_ACCESS_WRITE 0x5A | |
40 | /* also used to write the control/status reg (0x8D): */ | |
41 | #define W1_F29_FUNC_WRITE_COND_SEARCH_REG 0xCC | |
42 | #define W1_F29_FUNC_RESET_ACTIVITY_LATCHES 0xC3 | |
43 | ||
44 | #define W1_F29_SUCCESS_CONFIRM_BYTE 0xAA | |
45 | ||
46 | static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf) | |
47 | { | |
48 | u8 wrbuf[3]; | |
49 | dev_dbg(&sl->dev, | |
50 | "Reading with slave: %p, reg addr: %0#4x, buff addr: %p", | |
51 | sl, (unsigned int)address, buf); | |
52 | ||
53 | if (!buf) | |
54 | return -EINVAL; | |
55 | ||
b02f8bed | 56 | mutex_lock(&sl->master->bus_mutex); |
89610274 JFD |
57 | dev_dbg(&sl->dev, "mutex locked"); |
58 | ||
59 | if (w1_reset_select_slave(sl)) { | |
b02f8bed | 60 | mutex_unlock(&sl->master->bus_mutex); |
89610274 JFD |
61 | return -EIO; |
62 | } | |
63 | ||
64 | wrbuf[0] = W1_F29_FUNC_READ_PIO_REGS; | |
65 | wrbuf[1] = address; | |
66 | wrbuf[2] = 0; | |
67 | w1_write_block(sl->master, wrbuf, 3); | |
68 | *buf = w1_read_8(sl->master); | |
69 | ||
b02f8bed | 70 | mutex_unlock(&sl->master->bus_mutex); |
89610274 JFD |
71 | dev_dbg(&sl->dev, "mutex unlocked"); |
72 | return 1; | |
73 | } | |
74 | ||
75 | static ssize_t w1_f29_read_state( | |
76 | struct file *filp, struct kobject *kobj, | |
77 | struct bin_attribute *bin_attr, | |
78 | char *buf, loff_t off, size_t count) | |
79 | { | |
80 | dev_dbg(&kobj_to_w1_slave(kobj)->dev, | |
81 | "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", | |
82 | bin_attr->attr.name, kobj, (unsigned int)off, count, buf); | |
83 | if (count != 1 || off != 0) | |
84 | return -EFAULT; | |
85 | return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_LOGIG_STATE, buf); | |
86 | } | |
87 | ||
88 | static ssize_t w1_f29_read_output( | |
89 | struct file *filp, struct kobject *kobj, | |
90 | struct bin_attribute *bin_attr, | |
91 | char *buf, loff_t off, size_t count) | |
92 | { | |
93 | dev_dbg(&kobj_to_w1_slave(kobj)->dev, | |
94 | "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", | |
95 | bin_attr->attr.name, kobj, (unsigned int)off, count, buf); | |
96 | if (count != 1 || off != 0) | |
97 | return -EFAULT; | |
98 | return _read_reg(kobj_to_w1_slave(kobj), | |
99 | W1_F29_REG_OUTPUT_LATCH_STATE, buf); | |
100 | } | |
101 | ||
102 | static ssize_t w1_f29_read_activity( | |
103 | struct file *filp, struct kobject *kobj, | |
104 | struct bin_attribute *bin_attr, | |
105 | char *buf, loff_t off, size_t count) | |
106 | { | |
107 | dev_dbg(&kobj_to_w1_slave(kobj)->dev, | |
108 | "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", | |
109 | bin_attr->attr.name, kobj, (unsigned int)off, count, buf); | |
110 | if (count != 1 || off != 0) | |
111 | return -EFAULT; | |
112 | return _read_reg(kobj_to_w1_slave(kobj), | |
113 | W1_F29_REG_ACTIVITY_LATCH_STATE, buf); | |
114 | } | |
115 | ||
116 | static ssize_t w1_f29_read_cond_search_mask( | |
117 | struct file *filp, struct kobject *kobj, | |
118 | struct bin_attribute *bin_attr, | |
119 | char *buf, loff_t off, size_t count) | |
120 | { | |
121 | dev_dbg(&kobj_to_w1_slave(kobj)->dev, | |
122 | "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", | |
123 | bin_attr->attr.name, kobj, (unsigned int)off, count, buf); | |
124 | if (count != 1 || off != 0) | |
125 | return -EFAULT; | |
126 | return _read_reg(kobj_to_w1_slave(kobj), | |
127 | W1_F29_REG_COND_SEARCH_SELECT_MASK, buf); | |
128 | } | |
129 | ||
130 | static ssize_t w1_f29_read_cond_search_polarity( | |
131 | struct file *filp, struct kobject *kobj, | |
132 | struct bin_attribute *bin_attr, | |
133 | char *buf, loff_t off, size_t count) | |
134 | { | |
135 | if (count != 1 || off != 0) | |
136 | return -EFAULT; | |
137 | return _read_reg(kobj_to_w1_slave(kobj), | |
138 | W1_F29_REG_COND_SEARCH_POL_SELECT, buf); | |
139 | } | |
140 | ||
141 | static ssize_t w1_f29_read_status_control( | |
142 | struct file *filp, struct kobject *kobj, | |
143 | struct bin_attribute *bin_attr, | |
144 | char *buf, loff_t off, size_t count) | |
145 | { | |
146 | if (count != 1 || off != 0) | |
147 | return -EFAULT; | |
148 | return _read_reg(kobj_to_w1_slave(kobj), | |
149 | W1_F29_REG_CONTROL_AND_STATUS, buf); | |
150 | } | |
151 | ||
152 | ||
153 | ||
154 | ||
155 | static ssize_t w1_f29_write_output( | |
156 | struct file *filp, struct kobject *kobj, | |
157 | struct bin_attribute *bin_attr, | |
158 | char *buf, loff_t off, size_t count) | |
159 | { | |
160 | struct w1_slave *sl = kobj_to_w1_slave(kobj); | |
161 | u8 w1_buf[3]; | |
162 | u8 readBack; | |
163 | unsigned int retries = W1_F29_RETRIES; | |
164 | ||
165 | if (count != 1 || off != 0) | |
166 | return -EFAULT; | |
167 | ||
168 | dev_dbg(&sl->dev, "locking mutex for write_output"); | |
b02f8bed | 169 | mutex_lock(&sl->master->bus_mutex); |
89610274 JFD |
170 | dev_dbg(&sl->dev, "mutex locked"); |
171 | ||
172 | if (w1_reset_select_slave(sl)) | |
173 | goto error; | |
174 | ||
175 | while (retries--) { | |
176 | w1_buf[0] = W1_F29_FUNC_CHANN_ACCESS_WRITE; | |
177 | w1_buf[1] = *buf; | |
178 | w1_buf[2] = ~(*buf); | |
179 | w1_write_block(sl->master, w1_buf, 3); | |
180 | ||
181 | readBack = w1_read_8(sl->master); | |
aceca285 JFD |
182 | |
183 | if (readBack != W1_F29_SUCCESS_CONFIRM_BYTE) { | |
184 | if (w1_reset_resume_command(sl->master)) | |
185 | goto error; | |
186 | /* try again, the slave is ready for a command */ | |
187 | continue; | |
188 | } | |
189 | ||
190 | #ifdef CONFIG_W1_SLAVE_DS2408_READBACK | |
89610274 JFD |
191 | /* here the master could read another byte which |
192 | would be the PIO reg (the actual pin logic state) | |
193 | since in this driver we don't know which pins are | |
194 | in and outs, there's no value to read the state and | |
195 | compare. with (*buf) so end this command abruptly: */ | |
196 | if (w1_reset_resume_command(sl->master)) | |
197 | goto error; | |
198 | ||
89610274 JFD |
199 | /* go read back the output latches */ |
200 | /* (the direct effect of the write above) */ | |
201 | w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; | |
202 | w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE; | |
203 | w1_buf[2] = 0; | |
204 | w1_write_block(sl->master, w1_buf, 3); | |
205 | /* read the result of the READ_PIO_REGS command */ | |
aceca285 JFD |
206 | if (w1_read_8(sl->master) == *buf) |
207 | #endif | |
208 | { | |
89610274 | 209 | /* success! */ |
b02f8bed | 210 | mutex_unlock(&sl->master->bus_mutex); |
89610274 JFD |
211 | dev_dbg(&sl->dev, |
212 | "mutex unlocked, retries:%d", retries); | |
213 | return 1; | |
214 | } | |
215 | } | |
216 | error: | |
b02f8bed | 217 | mutex_unlock(&sl->master->bus_mutex); |
89610274 JFD |
218 | dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); |
219 | ||
220 | return -EIO; | |
221 | } | |
222 | ||
223 | ||
224 | /** | |
225 | * Writing to the activity file resets the activity latches. | |
226 | */ | |
227 | static ssize_t w1_f29_write_activity( | |
228 | struct file *filp, struct kobject *kobj, | |
229 | struct bin_attribute *bin_attr, | |
230 | char *buf, loff_t off, size_t count) | |
231 | { | |
232 | struct w1_slave *sl = kobj_to_w1_slave(kobj); | |
233 | unsigned int retries = W1_F29_RETRIES; | |
234 | ||
235 | if (count != 1 || off != 0) | |
236 | return -EFAULT; | |
237 | ||
b02f8bed | 238 | mutex_lock(&sl->master->bus_mutex); |
89610274 JFD |
239 | |
240 | if (w1_reset_select_slave(sl)) | |
241 | goto error; | |
242 | ||
243 | while (retries--) { | |
244 | w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES); | |
245 | if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) { | |
b02f8bed | 246 | mutex_unlock(&sl->master->bus_mutex); |
89610274 JFD |
247 | return 1; |
248 | } | |
249 | if (w1_reset_resume_command(sl->master)) | |
250 | goto error; | |
251 | } | |
252 | ||
253 | error: | |
b02f8bed | 254 | mutex_unlock(&sl->master->bus_mutex); |
89610274 JFD |
255 | return -EIO; |
256 | } | |
257 | ||
258 | static ssize_t w1_f29_write_status_control( | |
259 | struct file *filp, | |
260 | struct kobject *kobj, | |
261 | struct bin_attribute *bin_attr, | |
262 | char *buf, | |
263 | loff_t off, | |
264 | size_t count) | |
265 | { | |
266 | struct w1_slave *sl = kobj_to_w1_slave(kobj); | |
267 | u8 w1_buf[4]; | |
268 | unsigned int retries = W1_F29_RETRIES; | |
269 | ||
270 | if (count != 1 || off != 0) | |
271 | return -EFAULT; | |
272 | ||
b02f8bed | 273 | mutex_lock(&sl->master->bus_mutex); |
89610274 JFD |
274 | |
275 | if (w1_reset_select_slave(sl)) | |
276 | goto error; | |
277 | ||
278 | while (retries--) { | |
279 | w1_buf[0] = W1_F29_FUNC_WRITE_COND_SEARCH_REG; | |
280 | w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS; | |
281 | w1_buf[2] = 0; | |
282 | w1_buf[3] = *buf; | |
283 | ||
284 | w1_write_block(sl->master, w1_buf, 4); | |
285 | if (w1_reset_resume_command(sl->master)) | |
286 | goto error; | |
287 | ||
288 | w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; | |
289 | w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS; | |
290 | w1_buf[2] = 0; | |
291 | ||
292 | w1_write_block(sl->master, w1_buf, 3); | |
293 | if (w1_read_8(sl->master) == *buf) { | |
294 | /* success! */ | |
b02f8bed | 295 | mutex_unlock(&sl->master->bus_mutex); |
89610274 JFD |
296 | return 1; |
297 | } | |
298 | } | |
299 | error: | |
b02f8bed | 300 | mutex_unlock(&sl->master->bus_mutex); |
89610274 JFD |
301 | |
302 | return -EIO; | |
303 | } | |
304 | ||
d5528773 JFD |
305 | /* |
306 | * This is a special sequence we must do to ensure the P0 output is not stuck | |
307 | * in test mode. This is described in rev 2 of the ds2408's datasheet | |
308 | * (http://datasheets.maximintegrated.com/en/ds/DS2408.pdf) under | |
309 | * "APPLICATION INFORMATION/Power-up timing". | |
310 | */ | |
311 | static int w1_f29_disable_test_mode(struct w1_slave *sl) | |
312 | { | |
313 | int res; | |
314 | u8 magic[10] = {0x96, }; | |
315 | u64 rn = le64_to_cpu(*((u64*)&sl->reg_num)); | |
316 | ||
317 | memcpy(&magic[1], &rn, 8); | |
318 | magic[9] = 0x3C; | |
319 | ||
320 | mutex_lock(&sl->master->bus_mutex); | |
89610274 | 321 | |
d5528773 JFD |
322 | res = w1_reset_bus(sl->master); |
323 | if (res) | |
324 | goto out; | |
325 | w1_write_block(sl->master, magic, ARRAY_SIZE(magic)); | |
326 | ||
327 | res = w1_reset_bus(sl->master); | |
328 | out: | |
329 | mutex_unlock(&sl->master->bus_mutex); | |
330 | return res; | |
331 | } | |
89610274 | 332 | |
1116575d | 333 | static struct bin_attribute w1_f29_sysfs_bin_files[] = { |
89610274 JFD |
334 | { |
335 | .attr = { | |
336 | .name = "state", | |
337 | .mode = S_IRUGO, | |
338 | }, | |
339 | .size = 1, | |
340 | .read = w1_f29_read_state, | |
341 | }, | |
342 | { | |
343 | .attr = { | |
344 | .name = "output", | |
345 | .mode = S_IRUGO | S_IWUSR | S_IWGRP, | |
346 | }, | |
347 | .size = 1, | |
348 | .read = w1_f29_read_output, | |
349 | .write = w1_f29_write_output, | |
350 | }, | |
351 | { | |
352 | .attr = { | |
353 | .name = "activity", | |
354 | .mode = S_IRUGO, | |
355 | }, | |
356 | .size = 1, | |
357 | .read = w1_f29_read_activity, | |
358 | .write = w1_f29_write_activity, | |
359 | }, | |
360 | { | |
361 | .attr = { | |
362 | .name = "cond_search_mask", | |
363 | .mode = S_IRUGO, | |
364 | }, | |
365 | .size = 1, | |
366 | .read = w1_f29_read_cond_search_mask, | |
89610274 JFD |
367 | }, |
368 | { | |
369 | .attr = { | |
370 | .name = "cond_search_polarity", | |
371 | .mode = S_IRUGO, | |
372 | }, | |
373 | .size = 1, | |
374 | .read = w1_f29_read_cond_search_polarity, | |
89610274 JFD |
375 | }, |
376 | { | |
377 | .attr = { | |
378 | .name = "status_control", | |
379 | .mode = S_IRUGO | S_IWUSR | S_IWGRP, | |
380 | }, | |
381 | .size = 1, | |
382 | .read = w1_f29_read_status_control, | |
383 | .write = w1_f29_write_status_control, | |
384 | } | |
385 | }; | |
386 | ||
387 | static int w1_f29_add_slave(struct w1_slave *sl) | |
388 | { | |
389 | int err = 0; | |
390 | int i; | |
391 | ||
d5528773 JFD |
392 | err = w1_f29_disable_test_mode(sl); |
393 | if (err) | |
394 | return err; | |
395 | ||
1116575d | 396 | for (i = 0; i < ARRAY_SIZE(w1_f29_sysfs_bin_files) && !err; ++i) |
89610274 JFD |
397 | err = sysfs_create_bin_file( |
398 | &sl->dev.kobj, | |
399 | &(w1_f29_sysfs_bin_files[i])); | |
400 | if (err) | |
401 | while (--i >= 0) | |
402 | sysfs_remove_bin_file(&sl->dev.kobj, | |
403 | &(w1_f29_sysfs_bin_files[i])); | |
404 | return err; | |
405 | } | |
406 | ||
407 | static void w1_f29_remove_slave(struct w1_slave *sl) | |
408 | { | |
409 | int i; | |
1116575d | 410 | for (i = ARRAY_SIZE(w1_f29_sysfs_bin_files) - 1; i >= 0; --i) |
89610274 JFD |
411 | sysfs_remove_bin_file(&sl->dev.kobj, |
412 | &(w1_f29_sysfs_bin_files[i])); | |
413 | } | |
414 | ||
415 | static struct w1_family_ops w1_f29_fops = { | |
416 | .add_slave = w1_f29_add_slave, | |
417 | .remove_slave = w1_f29_remove_slave, | |
418 | }; | |
419 | ||
420 | static struct w1_family w1_family_29 = { | |
421 | .fid = W1_FAMILY_DS2408, | |
422 | .fops = &w1_f29_fops, | |
423 | }; | |
424 | ||
425 | static int __init w1_f29_init(void) | |
426 | { | |
427 | return w1_register_family(&w1_family_29); | |
428 | } | |
429 | ||
430 | static void __exit w1_f29_exit(void) | |
431 | { | |
432 | w1_unregister_family(&w1_family_29); | |
433 | } | |
434 | ||
435 | module_init(w1_f29_init); | |
436 | module_exit(w1_f29_exit); |