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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"); | |
25 | ||
26 | ||
27 | #define W1_F29_RETRIES 3 | |
28 | ||
29 | #define W1_F29_REG_LOGIG_STATE 0x88 /* R */ | |
30 | #define W1_F29_REG_OUTPUT_LATCH_STATE 0x89 /* R */ | |
31 | #define W1_F29_REG_ACTIVITY_LATCH_STATE 0x8A /* R */ | |
32 | #define W1_F29_REG_COND_SEARCH_SELECT_MASK 0x8B /* RW */ | |
33 | #define W1_F29_REG_COND_SEARCH_POL_SELECT 0x8C /* RW */ | |
34 | #define W1_F29_REG_CONTROL_AND_STATUS 0x8D /* RW */ | |
35 | ||
36 | #define W1_F29_FUNC_READ_PIO_REGS 0xF0 | |
37 | #define W1_F29_FUNC_CHANN_ACCESS_READ 0xF5 | |
38 | #define W1_F29_FUNC_CHANN_ACCESS_WRITE 0x5A | |
39 | /* also used to write the control/status reg (0x8D): */ | |
40 | #define W1_F29_FUNC_WRITE_COND_SEARCH_REG 0xCC | |
41 | #define W1_F29_FUNC_RESET_ACTIVITY_LATCHES 0xC3 | |
42 | ||
43 | #define W1_F29_SUCCESS_CONFIRM_BYTE 0xAA | |
44 | ||
45 | static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf) | |
46 | { | |
47 | u8 wrbuf[3]; | |
48 | dev_dbg(&sl->dev, | |
49 | "Reading with slave: %p, reg addr: %0#4x, buff addr: %p", | |
50 | sl, (unsigned int)address, buf); | |
51 | ||
52 | if (!buf) | |
53 | return -EINVAL; | |
54 | ||
55 | mutex_lock(&sl->master->mutex); | |
56 | dev_dbg(&sl->dev, "mutex locked"); | |
57 | ||
58 | if (w1_reset_select_slave(sl)) { | |
59 | mutex_unlock(&sl->master->mutex); | |
60 | return -EIO; | |
61 | } | |
62 | ||
63 | wrbuf[0] = W1_F29_FUNC_READ_PIO_REGS; | |
64 | wrbuf[1] = address; | |
65 | wrbuf[2] = 0; | |
66 | w1_write_block(sl->master, wrbuf, 3); | |
67 | *buf = w1_read_8(sl->master); | |
68 | ||
69 | mutex_unlock(&sl->master->mutex); | |
70 | dev_dbg(&sl->dev, "mutex unlocked"); | |
71 | return 1; | |
72 | } | |
73 | ||
74 | static ssize_t w1_f29_read_state( | |
75 | struct file *filp, struct kobject *kobj, | |
76 | struct bin_attribute *bin_attr, | |
77 | char *buf, loff_t off, size_t count) | |
78 | { | |
79 | dev_dbg(&kobj_to_w1_slave(kobj)->dev, | |
80 | "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", | |
81 | bin_attr->attr.name, kobj, (unsigned int)off, count, buf); | |
82 | if (count != 1 || off != 0) | |
83 | return -EFAULT; | |
84 | return _read_reg(kobj_to_w1_slave(kobj), W1_F29_REG_LOGIG_STATE, buf); | |
85 | } | |
86 | ||
87 | static ssize_t w1_f29_read_output( | |
88 | struct file *filp, struct kobject *kobj, | |
89 | struct bin_attribute *bin_attr, | |
90 | char *buf, loff_t off, size_t count) | |
91 | { | |
92 | dev_dbg(&kobj_to_w1_slave(kobj)->dev, | |
93 | "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", | |
94 | bin_attr->attr.name, kobj, (unsigned int)off, count, buf); | |
95 | if (count != 1 || off != 0) | |
96 | return -EFAULT; | |
97 | return _read_reg(kobj_to_w1_slave(kobj), | |
98 | W1_F29_REG_OUTPUT_LATCH_STATE, buf); | |
99 | } | |
100 | ||
101 | static ssize_t w1_f29_read_activity( | |
102 | struct file *filp, struct kobject *kobj, | |
103 | struct bin_attribute *bin_attr, | |
104 | char *buf, loff_t off, size_t count) | |
105 | { | |
106 | dev_dbg(&kobj_to_w1_slave(kobj)->dev, | |
107 | "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", | |
108 | bin_attr->attr.name, kobj, (unsigned int)off, count, buf); | |
109 | if (count != 1 || off != 0) | |
110 | return -EFAULT; | |
111 | return _read_reg(kobj_to_w1_slave(kobj), | |
112 | W1_F29_REG_ACTIVITY_LATCH_STATE, buf); | |
113 | } | |
114 | ||
115 | static ssize_t w1_f29_read_cond_search_mask( | |
116 | struct file *filp, struct kobject *kobj, | |
117 | struct bin_attribute *bin_attr, | |
118 | char *buf, loff_t off, size_t count) | |
119 | { | |
120 | dev_dbg(&kobj_to_w1_slave(kobj)->dev, | |
121 | "Reading %s kobj: %p, off: %0#10x, count: %zu, buff addr: %p", | |
122 | bin_attr->attr.name, kobj, (unsigned int)off, count, buf); | |
123 | if (count != 1 || off != 0) | |
124 | return -EFAULT; | |
125 | return _read_reg(kobj_to_w1_slave(kobj), | |
126 | W1_F29_REG_COND_SEARCH_SELECT_MASK, buf); | |
127 | } | |
128 | ||
129 | static ssize_t w1_f29_read_cond_search_polarity( | |
130 | struct file *filp, struct kobject *kobj, | |
131 | struct bin_attribute *bin_attr, | |
132 | char *buf, loff_t off, size_t count) | |
133 | { | |
134 | if (count != 1 || off != 0) | |
135 | return -EFAULT; | |
136 | return _read_reg(kobj_to_w1_slave(kobj), | |
137 | W1_F29_REG_COND_SEARCH_POL_SELECT, buf); | |
138 | } | |
139 | ||
140 | static ssize_t w1_f29_read_status_control( | |
141 | struct file *filp, struct kobject *kobj, | |
142 | struct bin_attribute *bin_attr, | |
143 | char *buf, loff_t off, size_t count) | |
144 | { | |
145 | if (count != 1 || off != 0) | |
146 | return -EFAULT; | |
147 | return _read_reg(kobj_to_w1_slave(kobj), | |
148 | W1_F29_REG_CONTROL_AND_STATUS, buf); | |
149 | } | |
150 | ||
151 | ||
152 | ||
153 | ||
154 | static ssize_t w1_f29_write_output( | |
155 | struct file *filp, struct kobject *kobj, | |
156 | struct bin_attribute *bin_attr, | |
157 | char *buf, loff_t off, size_t count) | |
158 | { | |
159 | struct w1_slave *sl = kobj_to_w1_slave(kobj); | |
160 | u8 w1_buf[3]; | |
161 | u8 readBack; | |
162 | unsigned int retries = W1_F29_RETRIES; | |
163 | ||
164 | if (count != 1 || off != 0) | |
165 | return -EFAULT; | |
166 | ||
167 | dev_dbg(&sl->dev, "locking mutex for write_output"); | |
168 | mutex_lock(&sl->master->mutex); | |
169 | dev_dbg(&sl->dev, "mutex locked"); | |
170 | ||
171 | if (w1_reset_select_slave(sl)) | |
172 | goto error; | |
173 | ||
174 | while (retries--) { | |
175 | w1_buf[0] = W1_F29_FUNC_CHANN_ACCESS_WRITE; | |
176 | w1_buf[1] = *buf; | |
177 | w1_buf[2] = ~(*buf); | |
178 | w1_write_block(sl->master, w1_buf, 3); | |
179 | ||
180 | readBack = w1_read_8(sl->master); | |
181 | /* here the master could read another byte which | |
182 | would be the PIO reg (the actual pin logic state) | |
183 | since in this driver we don't know which pins are | |
184 | in and outs, there's no value to read the state and | |
185 | compare. with (*buf) so end this command abruptly: */ | |
186 | if (w1_reset_resume_command(sl->master)) | |
187 | goto error; | |
188 | ||
189 | if (readBack != 0xAA) { | |
190 | /* try again, the slave is ready for a command */ | |
191 | continue; | |
192 | } | |
193 | ||
194 | /* go read back the output latches */ | |
195 | /* (the direct effect of the write above) */ | |
196 | w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; | |
197 | w1_buf[1] = W1_F29_REG_OUTPUT_LATCH_STATE; | |
198 | w1_buf[2] = 0; | |
199 | w1_write_block(sl->master, w1_buf, 3); | |
200 | /* read the result of the READ_PIO_REGS command */ | |
201 | if (w1_read_8(sl->master) == *buf) { | |
202 | /* success! */ | |
203 | mutex_unlock(&sl->master->mutex); | |
204 | dev_dbg(&sl->dev, | |
205 | "mutex unlocked, retries:%d", retries); | |
206 | return 1; | |
207 | } | |
208 | } | |
209 | error: | |
210 | mutex_unlock(&sl->master->mutex); | |
211 | dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries); | |
212 | ||
213 | return -EIO; | |
214 | } | |
215 | ||
216 | ||
217 | /** | |
218 | * Writing to the activity file resets the activity latches. | |
219 | */ | |
220 | static ssize_t w1_f29_write_activity( | |
221 | struct file *filp, struct kobject *kobj, | |
222 | struct bin_attribute *bin_attr, | |
223 | char *buf, loff_t off, size_t count) | |
224 | { | |
225 | struct w1_slave *sl = kobj_to_w1_slave(kobj); | |
226 | unsigned int retries = W1_F29_RETRIES; | |
227 | ||
228 | if (count != 1 || off != 0) | |
229 | return -EFAULT; | |
230 | ||
231 | mutex_lock(&sl->master->mutex); | |
232 | ||
233 | if (w1_reset_select_slave(sl)) | |
234 | goto error; | |
235 | ||
236 | while (retries--) { | |
237 | w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES); | |
238 | if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) { | |
239 | mutex_unlock(&sl->master->mutex); | |
240 | return 1; | |
241 | } | |
242 | if (w1_reset_resume_command(sl->master)) | |
243 | goto error; | |
244 | } | |
245 | ||
246 | error: | |
247 | mutex_unlock(&sl->master->mutex); | |
248 | return -EIO; | |
249 | } | |
250 | ||
251 | static ssize_t w1_f29_write_status_control( | |
252 | struct file *filp, | |
253 | struct kobject *kobj, | |
254 | struct bin_attribute *bin_attr, | |
255 | char *buf, | |
256 | loff_t off, | |
257 | size_t count) | |
258 | { | |
259 | struct w1_slave *sl = kobj_to_w1_slave(kobj); | |
260 | u8 w1_buf[4]; | |
261 | unsigned int retries = W1_F29_RETRIES; | |
262 | ||
263 | if (count != 1 || off != 0) | |
264 | return -EFAULT; | |
265 | ||
266 | mutex_lock(&sl->master->mutex); | |
267 | ||
268 | if (w1_reset_select_slave(sl)) | |
269 | goto error; | |
270 | ||
271 | while (retries--) { | |
272 | w1_buf[0] = W1_F29_FUNC_WRITE_COND_SEARCH_REG; | |
273 | w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS; | |
274 | w1_buf[2] = 0; | |
275 | w1_buf[3] = *buf; | |
276 | ||
277 | w1_write_block(sl->master, w1_buf, 4); | |
278 | if (w1_reset_resume_command(sl->master)) | |
279 | goto error; | |
280 | ||
281 | w1_buf[0] = W1_F29_FUNC_READ_PIO_REGS; | |
282 | w1_buf[1] = W1_F29_REG_CONTROL_AND_STATUS; | |
283 | w1_buf[2] = 0; | |
284 | ||
285 | w1_write_block(sl->master, w1_buf, 3); | |
286 | if (w1_read_8(sl->master) == *buf) { | |
287 | /* success! */ | |
288 | mutex_unlock(&sl->master->mutex); | |
289 | return 1; | |
290 | } | |
291 | } | |
292 | error: | |
293 | mutex_unlock(&sl->master->mutex); | |
294 | ||
295 | return -EIO; | |
296 | } | |
297 | ||
298 | ||
299 | ||
300 | #define NB_SYSFS_BIN_FILES 6 | |
301 | static struct bin_attribute w1_f29_sysfs_bin_files[NB_SYSFS_BIN_FILES] = { | |
302 | { | |
303 | .attr = { | |
304 | .name = "state", | |
305 | .mode = S_IRUGO, | |
306 | }, | |
307 | .size = 1, | |
308 | .read = w1_f29_read_state, | |
309 | }, | |
310 | { | |
311 | .attr = { | |
312 | .name = "output", | |
313 | .mode = S_IRUGO | S_IWUSR | S_IWGRP, | |
314 | }, | |
315 | .size = 1, | |
316 | .read = w1_f29_read_output, | |
317 | .write = w1_f29_write_output, | |
318 | }, | |
319 | { | |
320 | .attr = { | |
321 | .name = "activity", | |
322 | .mode = S_IRUGO, | |
323 | }, | |
324 | .size = 1, | |
325 | .read = w1_f29_read_activity, | |
326 | .write = w1_f29_write_activity, | |
327 | }, | |
328 | { | |
329 | .attr = { | |
330 | .name = "cond_search_mask", | |
331 | .mode = S_IRUGO, | |
332 | }, | |
333 | .size = 1, | |
334 | .read = w1_f29_read_cond_search_mask, | |
335 | .write = 0, | |
336 | }, | |
337 | { | |
338 | .attr = { | |
339 | .name = "cond_search_polarity", | |
340 | .mode = S_IRUGO, | |
341 | }, | |
342 | .size = 1, | |
343 | .read = w1_f29_read_cond_search_polarity, | |
344 | .write = 0, | |
345 | }, | |
346 | { | |
347 | .attr = { | |
348 | .name = "status_control", | |
349 | .mode = S_IRUGO | S_IWUSR | S_IWGRP, | |
350 | }, | |
351 | .size = 1, | |
352 | .read = w1_f29_read_status_control, | |
353 | .write = w1_f29_write_status_control, | |
354 | } | |
355 | }; | |
356 | ||
357 | static int w1_f29_add_slave(struct w1_slave *sl) | |
358 | { | |
359 | int err = 0; | |
360 | int i; | |
361 | ||
362 | for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i) | |
363 | err = sysfs_create_bin_file( | |
364 | &sl->dev.kobj, | |
365 | &(w1_f29_sysfs_bin_files[i])); | |
366 | if (err) | |
367 | while (--i >= 0) | |
368 | sysfs_remove_bin_file(&sl->dev.kobj, | |
369 | &(w1_f29_sysfs_bin_files[i])); | |
370 | return err; | |
371 | } | |
372 | ||
373 | static void w1_f29_remove_slave(struct w1_slave *sl) | |
374 | { | |
375 | int i; | |
58299449 | 376 | for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i) |
89610274 JFD |
377 | sysfs_remove_bin_file(&sl->dev.kobj, |
378 | &(w1_f29_sysfs_bin_files[i])); | |
379 | } | |
380 | ||
381 | static struct w1_family_ops w1_f29_fops = { | |
382 | .add_slave = w1_f29_add_slave, | |
383 | .remove_slave = w1_f29_remove_slave, | |
384 | }; | |
385 | ||
386 | static struct w1_family w1_family_29 = { | |
387 | .fid = W1_FAMILY_DS2408, | |
388 | .fops = &w1_f29_fops, | |
389 | }; | |
390 | ||
391 | static int __init w1_f29_init(void) | |
392 | { | |
393 | return w1_register_family(&w1_family_29); | |
394 | } | |
395 | ||
396 | static void __exit w1_f29_exit(void) | |
397 | { | |
398 | w1_unregister_family(&w1_family_29); | |
399 | } | |
400 | ||
401 | module_init(w1_f29_init); | |
402 | module_exit(w1_f29_exit); |