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1637db44 JC |
1 | /* The industrial I/O core, trigger handling functions |
2 | * | |
3 | * Copyright (c) 2008 Jonathan Cameron | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify it | |
6 | * under the terms of the GNU General Public License version 2 as published by | |
7 | * the Free Software Foundation. | |
8 | */ | |
9 | ||
10 | #include <linux/kernel.h> | |
1637db44 JC |
11 | #include <linux/idr.h> |
12 | #include <linux/err.h> | |
13 | #include <linux/device.h> | |
14 | #include <linux/interrupt.h> | |
15 | #include <linux/list.h> | |
5a0e3ad6 | 16 | #include <linux/slab.h> |
1637db44 JC |
17 | |
18 | #include "iio.h" | |
19 | #include "trigger.h" | |
df9c1c42 | 20 | #include "iio_core.h" |
74112d3f | 21 | #include "trigger_consumer.h" |
1637db44 JC |
22 | |
23 | /* RFC - Question of approach | |
24 | * Make the common case (single sensor single trigger) | |
25 | * simple by starting trigger capture from when first sensors | |
26 | * is added. | |
27 | * | |
28 | * Complex simultaneous start requires use of 'hold' functionality | |
29 | * of the trigger. (not implemented) | |
30 | * | |
31 | * Any other suggestions? | |
32 | */ | |
33 | ||
1637db44 JC |
34 | static DEFINE_IDR(iio_trigger_idr); |
35 | static DEFINE_SPINLOCK(iio_trigger_idr_lock); | |
36 | ||
37 | /* Single list of all available triggers */ | |
38 | static LIST_HEAD(iio_trigger_list); | |
39 | static DEFINE_MUTEX(iio_trigger_list_lock); | |
40 | ||
59c85e82 JC |
41 | /** |
42 | * iio_trigger_read_name() - retrieve useful identifying name | |
43 | **/ | |
44 | static ssize_t iio_trigger_read_name(struct device *dev, | |
45 | struct device_attribute *attr, | |
46 | char *buf) | |
47 | { | |
48 | struct iio_trigger *trig = dev_get_drvdata(dev); | |
49 | return sprintf(buf, "%s\n", trig->name); | |
50 | } | |
51 | ||
52 | static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL); | |
53 | ||
1637db44 JC |
54 | /** |
55 | * iio_trigger_register_sysfs() - create a device for this trigger | |
56 | * @trig_info: the trigger | |
57 | * | |
58 | * Also adds any control attribute registered by the trigger driver | |
59 | **/ | |
60 | static int iio_trigger_register_sysfs(struct iio_trigger *trig_info) | |
61 | { | |
59c85e82 JC |
62 | return sysfs_add_file_to_group(&trig_info->dev.kobj, |
63 | &dev_attr_name.attr, | |
64 | NULL); | |
1637db44 JC |
65 | } |
66 | ||
67 | static void iio_trigger_unregister_sysfs(struct iio_trigger *trig_info) | |
68 | { | |
59c85e82 JC |
69 | sysfs_remove_file_from_group(&trig_info->dev.kobj, |
70 | &dev_attr_name.attr, | |
71 | NULL); | |
1637db44 JC |
72 | } |
73 | ||
74 | ||
75 | /** | |
76 | * iio_trigger_register_id() - get a unique id for this trigger | |
77 | * @trig_info: the trigger | |
78 | **/ | |
79 | static int iio_trigger_register_id(struct iio_trigger *trig_info) | |
80 | { | |
81 | int ret = 0; | |
82 | ||
83 | idr_again: | |
84 | if (unlikely(idr_pre_get(&iio_trigger_idr, GFP_KERNEL) == 0)) | |
85 | return -ENOMEM; | |
86 | ||
87 | spin_lock(&iio_trigger_idr_lock); | |
88 | ret = idr_get_new(&iio_trigger_idr, NULL, &trig_info->id); | |
89 | spin_unlock(&iio_trigger_idr_lock); | |
90 | if (unlikely(ret == -EAGAIN)) | |
91 | goto idr_again; | |
92 | else if (likely(!ret)) | |
93 | trig_info->id = trig_info->id & MAX_ID_MASK; | |
94 | ||
95 | return ret; | |
96 | } | |
97 | ||
98 | /** | |
99 | * iio_trigger_unregister_id() - free up unique id for use by another trigger | |
100 | * @trig_info: the trigger | |
101 | **/ | |
102 | static void iio_trigger_unregister_id(struct iio_trigger *trig_info) | |
103 | { | |
74112d3f GKH |
104 | spin_lock(&iio_trigger_idr_lock); |
105 | idr_remove(&iio_trigger_idr, trig_info->id); | |
106 | spin_unlock(&iio_trigger_idr_lock); | |
1637db44 JC |
107 | } |
108 | ||
109 | int iio_trigger_register(struct iio_trigger *trig_info) | |
110 | { | |
111 | int ret; | |
112 | ||
113 | ret = iio_trigger_register_id(trig_info); | |
114 | if (ret) | |
115 | goto error_ret; | |
116 | /* Set the name used for the sysfs directory etc */ | |
117 | dev_set_name(&trig_info->dev, "trigger%ld", | |
118 | (unsigned long) trig_info->id); | |
119 | ||
120 | ret = device_add(&trig_info->dev); | |
121 | if (ret) | |
122 | goto error_unregister_id; | |
123 | ||
124 | ret = iio_trigger_register_sysfs(trig_info); | |
125 | if (ret) | |
126 | goto error_device_del; | |
127 | ||
128 | /* Add to list of available triggers held by the IIO core */ | |
129 | mutex_lock(&iio_trigger_list_lock); | |
130 | list_add_tail(&trig_info->list, &iio_trigger_list); | |
131 | mutex_unlock(&iio_trigger_list_lock); | |
132 | ||
133 | return 0; | |
134 | ||
135 | error_device_del: | |
136 | device_del(&trig_info->dev); | |
137 | error_unregister_id: | |
138 | iio_trigger_unregister_id(trig_info); | |
139 | error_ret: | |
140 | return ret; | |
141 | } | |
142 | EXPORT_SYMBOL(iio_trigger_register); | |
143 | ||
144 | void iio_trigger_unregister(struct iio_trigger *trig_info) | |
145 | { | |
1637db44 | 146 | mutex_lock(&iio_trigger_list_lock); |
582e5489 | 147 | list_del(&trig_info->list); |
1637db44 JC |
148 | mutex_unlock(&iio_trigger_list_lock); |
149 | ||
150 | iio_trigger_unregister_sysfs(trig_info); | |
151 | iio_trigger_unregister_id(trig_info); | |
152 | /* Possible issue in here */ | |
153 | device_unregister(&trig_info->dev); | |
154 | } | |
155 | EXPORT_SYMBOL(iio_trigger_unregister); | |
156 | ||
f6517f22 JC |
157 | static struct iio_trigger *iio_trigger_find_by_name(const char *name, |
158 | size_t len) | |
1637db44 | 159 | { |
f6517f22 | 160 | struct iio_trigger *trig = NULL, *iter; |
7c327857 | 161 | |
1637db44 | 162 | mutex_lock(&iio_trigger_list_lock); |
f6517f22 JC |
163 | list_for_each_entry(iter, &iio_trigger_list, list) |
164 | if (sysfs_streq(iter->name, name)) { | |
165 | trig = iter; | |
1637db44 JC |
166 | break; |
167 | } | |
1637db44 JC |
168 | mutex_unlock(&iio_trigger_list_lock); |
169 | ||
f6517f22 | 170 | return trig; |
5f87404d | 171 | } |
1637db44 | 172 | |
7b2c33b1 | 173 | void iio_trigger_poll(struct iio_trigger *trig, s64 time) |
1637db44 | 174 | { |
d96d1337 | 175 | int i; |
d96d1337 JC |
176 | if (!trig->use_count) { |
177 | for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) | |
178 | if (trig->subirqs[i].enabled) { | |
179 | trig->use_count++; | |
180 | generic_handle_irq(trig->subirq_base + i); | |
181 | } | |
182 | } | |
1637db44 JC |
183 | } |
184 | EXPORT_SYMBOL(iio_trigger_poll); | |
8384d957 JC |
185 | |
186 | irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private) | |
187 | { | |
188 | iio_trigger_poll(private, iio_get_time_ns()); | |
189 | return IRQ_HANDLED; | |
190 | } | |
191 | EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll); | |
1637db44 | 192 | |
1f785681 JC |
193 | void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time) |
194 | { | |
195 | int i; | |
196 | if (!trig->use_count) { | |
197 | for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) | |
198 | if (trig->subirqs[i].enabled) { | |
199 | trig->use_count++; | |
200 | handle_nested_irq(trig->subirq_base + i); | |
201 | } | |
202 | } | |
203 | } | |
204 | EXPORT_SYMBOL(iio_trigger_poll_chained); | |
205 | ||
1637db44 JC |
206 | void iio_trigger_notify_done(struct iio_trigger *trig) |
207 | { | |
208 | trig->use_count--; | |
d29f73db JC |
209 | if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable) |
210 | if (trig->ops->try_reenable(trig)) { | |
1637db44 | 211 | /* Missed and interrupt so launch new poll now */ |
7b2c33b1 | 212 | iio_trigger_poll(trig, 0); |
1637db44 JC |
213 | } |
214 | } | |
215 | EXPORT_SYMBOL(iio_trigger_notify_done); | |
216 | ||
1637db44 JC |
217 | /* Trigger Consumer related functions */ |
218 | ||
219 | /* Complexity in here. With certain triggers (datardy) an acknowledgement | |
220 | * may be needed if the pollfuncs do not include the data read for the | |
221 | * triggering device. | |
222 | * This is not currently handled. Alternative of not enabling trigger unless | |
223 | * the relevant function is in there may be the best option. | |
224 | */ | |
225 | /* Worth protecting against double additions?*/ | |
226 | int iio_trigger_attach_poll_func(struct iio_trigger *trig, | |
227 | struct iio_poll_func *pf) | |
228 | { | |
229 | int ret = 0; | |
51c060a0 JC |
230 | bool notinuse |
231 | = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER); | |
232 | ||
233 | pf->irq = iio_trigger_get_irq(trig); | |
234 | ret = request_threaded_irq(pf->irq, pf->h, pf->thread, | |
235 | pf->type, pf->name, | |
236 | pf); | |
d29f73db JC |
237 | if (trig->ops && trig->ops->set_trigger_state && notinuse) |
238 | ret = trig->ops->set_trigger_state(trig, true); | |
d96d1337 | 239 | |
1637db44 JC |
240 | return ret; |
241 | } | |
242 | EXPORT_SYMBOL(iio_trigger_attach_poll_func); | |
243 | ||
244 | int iio_trigger_dettach_poll_func(struct iio_trigger *trig, | |
245 | struct iio_poll_func *pf) | |
246 | { | |
51c060a0 JC |
247 | int ret = 0; |
248 | bool no_other_users | |
249 | = (bitmap_weight(trig->pool, | |
250 | CONFIG_IIO_CONSUMERS_PER_TRIGGER) | |
251 | == 1); | |
d29f73db JC |
252 | if (trig->ops && trig->ops->set_trigger_state && no_other_users) { |
253 | ret = trig->ops->set_trigger_state(trig, false); | |
51c060a0 JC |
254 | if (ret) |
255 | goto error_ret; | |
1637db44 | 256 | } |
51c060a0 JC |
257 | iio_trigger_put_irq(trig, pf->irq); |
258 | free_irq(pf->irq, pf); | |
1637db44 JC |
259 | |
260 | error_ret: | |
261 | return ret; | |
262 | } | |
263 | EXPORT_SYMBOL(iio_trigger_dettach_poll_func); | |
264 | ||
d96d1337 JC |
265 | irqreturn_t iio_pollfunc_store_time(int irq, void *p) |
266 | { | |
267 | struct iio_poll_func *pf = p; | |
268 | pf->timestamp = iio_get_time_ns(); | |
269 | return IRQ_WAKE_THREAD; | |
270 | } | |
271 | EXPORT_SYMBOL(iio_pollfunc_store_time); | |
272 | ||
21b185f8 JC |
273 | struct iio_poll_func |
274 | *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p), | |
275 | irqreturn_t (*thread)(int irq, void *p), | |
276 | int type, | |
277 | void *private, | |
278 | const char *fmt, | |
279 | ...) | |
280 | { | |
281 | va_list vargs; | |
282 | struct iio_poll_func *pf; | |
283 | ||
284 | pf = kmalloc(sizeof *pf, GFP_KERNEL); | |
285 | if (pf == NULL) | |
286 | return NULL; | |
287 | va_start(vargs, fmt); | |
288 | pf->name = kvasprintf(GFP_KERNEL, fmt, vargs); | |
289 | va_end(vargs); | |
290 | if (pf->name == NULL) { | |
291 | kfree(pf); | |
292 | return NULL; | |
293 | } | |
294 | pf->h = h; | |
295 | pf->thread = thread; | |
296 | pf->type = type; | |
c11c4eeb | 297 | pf->private_data = private; |
21b185f8 JC |
298 | |
299 | return pf; | |
300 | } | |
301 | EXPORT_SYMBOL_GPL(iio_alloc_pollfunc); | |
302 | ||
303 | void iio_dealloc_pollfunc(struct iio_poll_func *pf) | |
304 | { | |
305 | kfree(pf->name); | |
306 | kfree(pf); | |
307 | } | |
308 | EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc); | |
309 | ||
1637db44 | 310 | /** |
751a3700 | 311 | * iio_trigger_read_currrent() - trigger consumer sysfs query which trigger |
1637db44 JC |
312 | * |
313 | * For trigger consumers the current_trigger interface allows the trigger | |
314 | * used by the device to be queried. | |
315 | **/ | |
316 | static ssize_t iio_trigger_read_current(struct device *dev, | |
317 | struct device_attribute *attr, | |
318 | char *buf) | |
319 | { | |
320 | struct iio_dev *dev_info = dev_get_drvdata(dev); | |
321 | int len = 0; | |
322 | if (dev_info->trig) | |
3c9bbf58 JC |
323 | len = sprintf(buf, |
324 | "%s\n", | |
325 | dev_info->trig->name); | |
1637db44 JC |
326 | return len; |
327 | } | |
328 | ||
329 | /** | |
330 | * iio_trigger_write_current() trigger consumer sysfs set current trigger | |
331 | * | |
332 | * For trigger consumers the current_trigger interface allows the trigger | |
333 | * used for this device to be specified at run time based on the triggers | |
334 | * name. | |
335 | **/ | |
336 | static ssize_t iio_trigger_write_current(struct device *dev, | |
337 | struct device_attribute *attr, | |
338 | const char *buf, | |
339 | size_t len) | |
340 | { | |
341 | struct iio_dev *dev_info = dev_get_drvdata(dev); | |
342 | struct iio_trigger *oldtrig = dev_info->trig; | |
43a4360e MH |
343 | struct iio_trigger *trig; |
344 | int ret; | |
345 | ||
1637db44 JC |
346 | mutex_lock(&dev_info->mlock); |
347 | if (dev_info->currentmode == INDIO_RING_TRIGGERED) { | |
348 | mutex_unlock(&dev_info->mlock); | |
349 | return -EBUSY; | |
350 | } | |
351 | mutex_unlock(&dev_info->mlock); | |
352 | ||
43a4360e MH |
353 | trig = iio_trigger_find_by_name(buf, len); |
354 | ||
355 | if (trig && dev_info->info->validate_trigger) { | |
356 | ret = dev_info->info->validate_trigger(dev_info, trig); | |
357 | if (ret) | |
358 | return ret; | |
359 | } | |
360 | ||
d29f73db JC |
361 | if (trig && trig->ops && trig->ops->validate_device) { |
362 | ret = trig->ops->validate_device(trig, dev_info); | |
43a4360e MH |
363 | if (ret) |
364 | return ret; | |
365 | } | |
366 | ||
367 | dev_info->trig = trig; | |
368 | ||
1637db44 JC |
369 | if (oldtrig && dev_info->trig != oldtrig) |
370 | iio_put_trigger(oldtrig); | |
371 | if (dev_info->trig) | |
372 | iio_get_trigger(dev_info->trig); | |
373 | ||
374 | return len; | |
375 | } | |
376 | ||
74112d3f GKH |
377 | static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR, |
378 | iio_trigger_read_current, | |
379 | iio_trigger_write_current); | |
1637db44 JC |
380 | |
381 | static struct attribute *iio_trigger_consumer_attrs[] = { | |
382 | &dev_attr_current_trigger.attr, | |
383 | NULL, | |
384 | }; | |
385 | ||
386 | static const struct attribute_group iio_trigger_consumer_attr_group = { | |
387 | .name = "trigger", | |
388 | .attrs = iio_trigger_consumer_attrs, | |
389 | }; | |
390 | ||
391 | static void iio_trig_release(struct device *device) | |
392 | { | |
393 | struct iio_trigger *trig = to_iio_trigger(device); | |
d96d1337 JC |
394 | int i; |
395 | ||
396 | if (trig->subirq_base) { | |
397 | for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) { | |
398 | irq_modify_status(trig->subirq_base + i, | |
399 | IRQ_NOAUTOEN, | |
400 | IRQ_NOREQUEST | IRQ_NOPROBE); | |
401 | irq_set_chip(trig->subirq_base + i, | |
402 | NULL); | |
403 | irq_set_handler(trig->subirq_base + i, | |
404 | NULL); | |
405 | } | |
406 | ||
407 | irq_free_descs(trig->subirq_base, | |
408 | CONFIG_IIO_CONSUMERS_PER_TRIGGER); | |
409 | } | |
59c85e82 | 410 | kfree(trig->name); |
1637db44 JC |
411 | kfree(trig); |
412 | iio_put(); | |
413 | } | |
414 | ||
415 | static struct device_type iio_trig_type = { | |
416 | .release = iio_trig_release, | |
417 | }; | |
418 | ||
d96d1337 JC |
419 | static void iio_trig_subirqmask(struct irq_data *d) |
420 | { | |
421 | struct irq_chip *chip = irq_data_get_irq_chip(d); | |
422 | struct iio_trigger *trig | |
423 | = container_of(chip, | |
424 | struct iio_trigger, subirq_chip); | |
425 | trig->subirqs[d->irq - trig->subirq_base].enabled = false; | |
426 | } | |
427 | ||
428 | static void iio_trig_subirqunmask(struct irq_data *d) | |
429 | { | |
430 | struct irq_chip *chip = irq_data_get_irq_chip(d); | |
431 | struct iio_trigger *trig | |
432 | = container_of(chip, | |
433 | struct iio_trigger, subirq_chip); | |
434 | trig->subirqs[d->irq - trig->subirq_base].enabled = true; | |
435 | } | |
436 | ||
59c85e82 | 437 | struct iio_trigger *iio_allocate_trigger(const char *fmt, ...) |
1637db44 | 438 | { |
59c85e82 | 439 | va_list vargs; |
1637db44 JC |
440 | struct iio_trigger *trig; |
441 | trig = kzalloc(sizeof *trig, GFP_KERNEL); | |
442 | if (trig) { | |
d96d1337 | 443 | int i; |
1637db44 | 444 | trig->dev.type = &iio_trig_type; |
5aaaeba8 | 445 | trig->dev.bus = &iio_bus_type; |
1637db44 JC |
446 | device_initialize(&trig->dev); |
447 | dev_set_drvdata(&trig->dev, (void *)trig); | |
d96d1337 | 448 | |
59c85e82 JC |
449 | mutex_init(&trig->pool_lock); |
450 | trig->subirq_base | |
451 | = irq_alloc_descs(-1, 0, | |
452 | CONFIG_IIO_CONSUMERS_PER_TRIGGER, | |
453 | 0); | |
454 | if (trig->subirq_base < 0) { | |
455 | kfree(trig); | |
456 | return NULL; | |
457 | } | |
458 | va_start(vargs, fmt); | |
459 | trig->name = kvasprintf(GFP_KERNEL, fmt, vargs); | |
460 | va_end(vargs); | |
461 | if (trig->name == NULL) { | |
462 | irq_free_descs(trig->subirq_base, | |
463 | CONFIG_IIO_CONSUMERS_PER_TRIGGER); | |
464 | kfree(trig); | |
465 | return NULL; | |
466 | } | |
467 | trig->subirq_chip.name = trig->name; | |
468 | trig->subirq_chip.irq_mask = &iio_trig_subirqmask; | |
469 | trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask; | |
470 | for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) { | |
471 | irq_set_chip(trig->subirq_base + i, | |
472 | &trig->subirq_chip); | |
473 | irq_set_handler(trig->subirq_base + i, | |
474 | &handle_simple_irq); | |
475 | irq_modify_status(trig->subirq_base + i, | |
476 | IRQ_NOREQUEST | IRQ_NOAUTOEN, | |
477 | IRQ_NOPROBE); | |
d96d1337 | 478 | } |
1637db44 | 479 | iio_get(); |
5f9c035c | 480 | get_device(&trig->dev); |
1637db44 JC |
481 | } |
482 | return trig; | |
483 | } | |
484 | EXPORT_SYMBOL(iio_allocate_trigger); | |
485 | ||
486 | void iio_free_trigger(struct iio_trigger *trig) | |
487 | { | |
488 | if (trig) | |
489 | put_device(&trig->dev); | |
490 | } | |
491 | EXPORT_SYMBOL(iio_free_trigger); | |
492 | ||
493 | int iio_device_register_trigger_consumer(struct iio_dev *dev_info) | |
494 | { | |
495 | int ret; | |
496 | ret = sysfs_create_group(&dev_info->dev.kobj, | |
497 | &iio_trigger_consumer_attr_group); | |
498 | return ret; | |
499 | } | |
500 | EXPORT_SYMBOL(iio_device_register_trigger_consumer); | |
501 | ||
502 | int iio_device_unregister_trigger_consumer(struct iio_dev *dev_info) | |
503 | { | |
5f9c035c JC |
504 | /* Clean up and associated but not attached triggers references */ |
505 | if (dev_info->trig) | |
506 | iio_put_trigger(dev_info->trig); | |
1637db44 JC |
507 | sysfs_remove_group(&dev_info->dev.kobj, |
508 | &iio_trigger_consumer_attr_group); | |
509 | return 0; | |
510 | } | |
511 | EXPORT_SYMBOL(iio_device_unregister_trigger_consumer); | |
512 | ||
c3db00cc JC |
513 | int iio_triggered_ring_postenable(struct iio_dev *indio_dev) |
514 | { | |
515 | return indio_dev->trig | |
516 | ? iio_trigger_attach_poll_func(indio_dev->trig, | |
517 | indio_dev->pollfunc) | |
518 | : 0; | |
519 | } | |
520 | EXPORT_SYMBOL(iio_triggered_ring_postenable); | |
521 | ||
522 | int iio_triggered_ring_predisable(struct iio_dev *indio_dev) | |
523 | { | |
524 | return indio_dev->trig | |
525 | ? iio_trigger_dettach_poll_func(indio_dev->trig, | |
526 | indio_dev->pollfunc) | |
527 | : 0; | |
528 | } | |
529 | EXPORT_SYMBOL(iio_triggered_ring_predisable); |