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