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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 | 17 | |
06458e27 JC |
18 | #include <linux/iio/iio.h> |
19 | #include <linux/iio/trigger.h> | |
df9c1c42 | 20 | #include "iio_core.h" |
6aea1c36 | 21 | #include "iio_core_trigger.h" |
06458e27 | 22 | #include <linux/iio/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 | ||
47c24fdd | 35 | static DEFINE_IDA(iio_trigger_ida); |
1637db44 JC |
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 | { | |
971ff1db | 48 | struct iio_trigger *trig = to_iio_trigger(dev); |
59c85e82 JC |
49 | return sprintf(buf, "%s\n", trig->name); |
50 | } | |
51 | ||
52 | static DEVICE_ATTR(name, S_IRUGO, iio_trigger_read_name, NULL); | |
53 | ||
6d459aa0 LPC |
54 | static struct attribute *iio_trig_dev_attrs[] = { |
55 | &dev_attr_name.attr, | |
56 | NULL, | |
57 | }; | |
1637db44 | 58 | |
6d459aa0 LPC |
59 | static struct attribute_group iio_trig_attr_group = { |
60 | .attrs = iio_trig_dev_attrs, | |
61 | }; | |
62 | ||
63 | static const struct attribute_group *iio_trig_attr_groups[] = { | |
64 | &iio_trig_attr_group, | |
65 | NULL | |
66 | }; | |
1637db44 | 67 | |
1637db44 JC |
68 | int iio_trigger_register(struct iio_trigger *trig_info) |
69 | { | |
70 | int ret; | |
71 | ||
47c24fdd JC |
72 | trig_info->id = ida_simple_get(&iio_trigger_ida, 0, 0, GFP_KERNEL); |
73 | if (trig_info->id < 0) { | |
74 | ret = trig_info->id; | |
1637db44 | 75 | goto error_ret; |
47c24fdd | 76 | } |
1637db44 JC |
77 | /* Set the name used for the sysfs directory etc */ |
78 | dev_set_name(&trig_info->dev, "trigger%ld", | |
79 | (unsigned long) trig_info->id); | |
80 | ||
81 | ret = device_add(&trig_info->dev); | |
82 | if (ret) | |
83 | goto error_unregister_id; | |
84 | ||
1637db44 JC |
85 | /* Add to list of available triggers held by the IIO core */ |
86 | mutex_lock(&iio_trigger_list_lock); | |
87 | list_add_tail(&trig_info->list, &iio_trigger_list); | |
88 | mutex_unlock(&iio_trigger_list_lock); | |
89 | ||
90 | return 0; | |
91 | ||
1637db44 | 92 | error_unregister_id: |
47c24fdd | 93 | ida_simple_remove(&iio_trigger_ida, trig_info->id); |
1637db44 JC |
94 | error_ret: |
95 | return ret; | |
96 | } | |
97 | EXPORT_SYMBOL(iio_trigger_register); | |
98 | ||
99 | void iio_trigger_unregister(struct iio_trigger *trig_info) | |
100 | { | |
1637db44 | 101 | mutex_lock(&iio_trigger_list_lock); |
582e5489 | 102 | list_del(&trig_info->list); |
1637db44 JC |
103 | mutex_unlock(&iio_trigger_list_lock); |
104 | ||
47c24fdd | 105 | ida_simple_remove(&iio_trigger_ida, trig_info->id); |
1637db44 JC |
106 | /* Possible issue in here */ |
107 | device_unregister(&trig_info->dev); | |
108 | } | |
109 | EXPORT_SYMBOL(iio_trigger_unregister); | |
110 | ||
f6517f22 JC |
111 | static struct iio_trigger *iio_trigger_find_by_name(const char *name, |
112 | size_t len) | |
1637db44 | 113 | { |
f6517f22 | 114 | struct iio_trigger *trig = NULL, *iter; |
7c327857 | 115 | |
1637db44 | 116 | mutex_lock(&iio_trigger_list_lock); |
f6517f22 JC |
117 | list_for_each_entry(iter, &iio_trigger_list, list) |
118 | if (sysfs_streq(iter->name, name)) { | |
119 | trig = iter; | |
1637db44 JC |
120 | break; |
121 | } | |
1637db44 JC |
122 | mutex_unlock(&iio_trigger_list_lock); |
123 | ||
f6517f22 | 124 | return trig; |
5f87404d | 125 | } |
1637db44 | 126 | |
7b2c33b1 | 127 | void iio_trigger_poll(struct iio_trigger *trig, s64 time) |
1637db44 | 128 | { |
d96d1337 | 129 | int i; |
cb6c89a0 | 130 | if (!trig->use_count) |
d96d1337 JC |
131 | for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) |
132 | if (trig->subirqs[i].enabled) { | |
133 | trig->use_count++; | |
134 | generic_handle_irq(trig->subirq_base + i); | |
135 | } | |
1637db44 JC |
136 | } |
137 | EXPORT_SYMBOL(iio_trigger_poll); | |
8384d957 JC |
138 | |
139 | irqreturn_t iio_trigger_generic_data_rdy_poll(int irq, void *private) | |
140 | { | |
141 | iio_trigger_poll(private, iio_get_time_ns()); | |
142 | return IRQ_HANDLED; | |
143 | } | |
144 | EXPORT_SYMBOL(iio_trigger_generic_data_rdy_poll); | |
1637db44 | 145 | |
1f785681 JC |
146 | void iio_trigger_poll_chained(struct iio_trigger *trig, s64 time) |
147 | { | |
148 | int i; | |
e69616b1 | 149 | if (!trig->use_count) |
1f785681 JC |
150 | for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) |
151 | if (trig->subirqs[i].enabled) { | |
152 | trig->use_count++; | |
153 | handle_nested_irq(trig->subirq_base + i); | |
154 | } | |
1f785681 JC |
155 | } |
156 | EXPORT_SYMBOL(iio_trigger_poll_chained); | |
157 | ||
1637db44 JC |
158 | void iio_trigger_notify_done(struct iio_trigger *trig) |
159 | { | |
160 | trig->use_count--; | |
d29f73db | 161 | if (trig->use_count == 0 && trig->ops && trig->ops->try_reenable) |
e69616b1 | 162 | if (trig->ops->try_reenable(trig)) |
860c9c54 | 163 | /* Missed an interrupt so launch new poll now */ |
7b2c33b1 | 164 | iio_trigger_poll(trig, 0); |
1637db44 JC |
165 | } |
166 | EXPORT_SYMBOL(iio_trigger_notify_done); | |
167 | ||
1637db44 | 168 | /* Trigger Consumer related functions */ |
208b813c JC |
169 | static int iio_trigger_get_irq(struct iio_trigger *trig) |
170 | { | |
171 | int ret; | |
172 | mutex_lock(&trig->pool_lock); | |
173 | ret = bitmap_find_free_region(trig->pool, | |
174 | CONFIG_IIO_CONSUMERS_PER_TRIGGER, | |
175 | ilog2(1)); | |
176 | mutex_unlock(&trig->pool_lock); | |
177 | if (ret >= 0) | |
178 | ret += trig->subirq_base; | |
179 | ||
180 | return ret; | |
181 | } | |
182 | ||
183 | static void iio_trigger_put_irq(struct iio_trigger *trig, int irq) | |
184 | { | |
185 | mutex_lock(&trig->pool_lock); | |
186 | clear_bit(irq - trig->subirq_base, trig->pool); | |
187 | mutex_unlock(&trig->pool_lock); | |
188 | } | |
1637db44 JC |
189 | |
190 | /* Complexity in here. With certain triggers (datardy) an acknowledgement | |
191 | * may be needed if the pollfuncs do not include the data read for the | |
192 | * triggering device. | |
193 | * This is not currently handled. Alternative of not enabling trigger unless | |
194 | * the relevant function is in there may be the best option. | |
195 | */ | |
860c9c54 | 196 | /* Worth protecting against double additions? */ |
208b813c JC |
197 | static int iio_trigger_attach_poll_func(struct iio_trigger *trig, |
198 | struct iio_poll_func *pf) | |
1637db44 JC |
199 | { |
200 | int ret = 0; | |
51c060a0 JC |
201 | bool notinuse |
202 | = bitmap_empty(trig->pool, CONFIG_IIO_CONSUMERS_PER_TRIGGER); | |
203 | ||
860c9c54 | 204 | /* Prevent the module from being removed whilst attached to a trigger */ |
f60c4a02 | 205 | __module_get(pf->indio_dev->info->driver_module); |
51c060a0 JC |
206 | pf->irq = iio_trigger_get_irq(trig); |
207 | ret = request_threaded_irq(pf->irq, pf->h, pf->thread, | |
208 | pf->type, pf->name, | |
209 | pf); | |
5dd72ecb JC |
210 | if (ret < 0) { |
211 | module_put(pf->indio_dev->info->driver_module); | |
212 | return ret; | |
213 | } | |
214 | ||
215 | if (trig->ops && trig->ops->set_trigger_state && notinuse) { | |
d29f73db | 216 | ret = trig->ops->set_trigger_state(trig, true); |
5dd72ecb JC |
217 | if (ret < 0) |
218 | module_put(pf->indio_dev->info->driver_module); | |
219 | } | |
d96d1337 | 220 | |
1637db44 JC |
221 | return ret; |
222 | } | |
1637db44 | 223 | |
034bd7b5 | 224 | static int iio_trigger_detach_poll_func(struct iio_trigger *trig, |
208b813c | 225 | struct iio_poll_func *pf) |
1637db44 | 226 | { |
51c060a0 JC |
227 | int ret = 0; |
228 | bool no_other_users | |
229 | = (bitmap_weight(trig->pool, | |
230 | CONFIG_IIO_CONSUMERS_PER_TRIGGER) | |
231 | == 1); | |
d29f73db JC |
232 | if (trig->ops && trig->ops->set_trigger_state && no_other_users) { |
233 | ret = trig->ops->set_trigger_state(trig, false); | |
51c060a0 JC |
234 | if (ret) |
235 | goto error_ret; | |
1637db44 | 236 | } |
51c060a0 JC |
237 | iio_trigger_put_irq(trig, pf->irq); |
238 | free_irq(pf->irq, pf); | |
f60c4a02 | 239 | module_put(pf->indio_dev->info->driver_module); |
1637db44 JC |
240 | |
241 | error_ret: | |
242 | return ret; | |
243 | } | |
1637db44 | 244 | |
d96d1337 JC |
245 | irqreturn_t iio_pollfunc_store_time(int irq, void *p) |
246 | { | |
247 | struct iio_poll_func *pf = p; | |
248 | pf->timestamp = iio_get_time_ns(); | |
249 | return IRQ_WAKE_THREAD; | |
250 | } | |
251 | EXPORT_SYMBOL(iio_pollfunc_store_time); | |
252 | ||
21b185f8 JC |
253 | struct iio_poll_func |
254 | *iio_alloc_pollfunc(irqreturn_t (*h)(int irq, void *p), | |
255 | irqreturn_t (*thread)(int irq, void *p), | |
256 | int type, | |
e65bc6ac | 257 | struct iio_dev *indio_dev, |
21b185f8 JC |
258 | const char *fmt, |
259 | ...) | |
260 | { | |
261 | va_list vargs; | |
262 | struct iio_poll_func *pf; | |
263 | ||
264 | pf = kmalloc(sizeof *pf, GFP_KERNEL); | |
265 | if (pf == NULL) | |
266 | return NULL; | |
267 | va_start(vargs, fmt); | |
268 | pf->name = kvasprintf(GFP_KERNEL, fmt, vargs); | |
269 | va_end(vargs); | |
270 | if (pf->name == NULL) { | |
271 | kfree(pf); | |
272 | return NULL; | |
273 | } | |
274 | pf->h = h; | |
275 | pf->thread = thread; | |
276 | pf->type = type; | |
e65bc6ac | 277 | pf->indio_dev = indio_dev; |
21b185f8 JC |
278 | |
279 | return pf; | |
280 | } | |
281 | EXPORT_SYMBOL_GPL(iio_alloc_pollfunc); | |
282 | ||
283 | void iio_dealloc_pollfunc(struct iio_poll_func *pf) | |
284 | { | |
285 | kfree(pf->name); | |
286 | kfree(pf); | |
287 | } | |
288 | EXPORT_SYMBOL_GPL(iio_dealloc_pollfunc); | |
289 | ||
1637db44 | 290 | /** |
860c9c54 | 291 | * iio_trigger_read_current() - trigger consumer sysfs query current trigger |
1637db44 JC |
292 | * |
293 | * For trigger consumers the current_trigger interface allows the trigger | |
294 | * used by the device to be queried. | |
295 | **/ | |
296 | static ssize_t iio_trigger_read_current(struct device *dev, | |
297 | struct device_attribute *attr, | |
298 | char *buf) | |
299 | { | |
e53f5ac5 | 300 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
cb6c89a0 | 301 | |
f8c6f4e9 JC |
302 | if (indio_dev->trig) |
303 | return sprintf(buf, "%s\n", indio_dev->trig->name); | |
cb6c89a0 | 304 | return 0; |
1637db44 JC |
305 | } |
306 | ||
307 | /** | |
860c9c54 | 308 | * iio_trigger_write_current() - trigger consumer sysfs set current trigger |
1637db44 JC |
309 | * |
310 | * For trigger consumers the current_trigger interface allows the trigger | |
311 | * used for this device to be specified at run time based on the triggers | |
312 | * name. | |
313 | **/ | |
314 | static ssize_t iio_trigger_write_current(struct device *dev, | |
315 | struct device_attribute *attr, | |
316 | const char *buf, | |
317 | size_t len) | |
318 | { | |
e53f5ac5 | 319 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
f8c6f4e9 | 320 | struct iio_trigger *oldtrig = indio_dev->trig; |
43a4360e MH |
321 | struct iio_trigger *trig; |
322 | int ret; | |
323 | ||
f8c6f4e9 JC |
324 | mutex_lock(&indio_dev->mlock); |
325 | if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) { | |
326 | mutex_unlock(&indio_dev->mlock); | |
1637db44 JC |
327 | return -EBUSY; |
328 | } | |
f8c6f4e9 | 329 | mutex_unlock(&indio_dev->mlock); |
1637db44 | 330 | |
43a4360e | 331 | trig = iio_trigger_find_by_name(buf, len); |
5dd72ecb JC |
332 | if (oldtrig == trig) |
333 | return len; | |
43a4360e | 334 | |
f8c6f4e9 JC |
335 | if (trig && indio_dev->info->validate_trigger) { |
336 | ret = indio_dev->info->validate_trigger(indio_dev, trig); | |
43a4360e MH |
337 | if (ret) |
338 | return ret; | |
339 | } | |
340 | ||
d29f73db | 341 | if (trig && trig->ops && trig->ops->validate_device) { |
f8c6f4e9 | 342 | ret = trig->ops->validate_device(trig, indio_dev); |
43a4360e MH |
343 | if (ret) |
344 | return ret; | |
345 | } | |
346 | ||
f8c6f4e9 | 347 | indio_dev->trig = trig; |
43a4360e | 348 | |
f8c6f4e9 | 349 | if (oldtrig && indio_dev->trig != oldtrig) |
7cbb7537 | 350 | iio_trigger_put(oldtrig); |
f8c6f4e9 | 351 | if (indio_dev->trig) |
7cbb7537 | 352 | iio_trigger_get(indio_dev->trig); |
1637db44 JC |
353 | |
354 | return len; | |
355 | } | |
356 | ||
74112d3f GKH |
357 | static DEVICE_ATTR(current_trigger, S_IRUGO | S_IWUSR, |
358 | iio_trigger_read_current, | |
359 | iio_trigger_write_current); | |
1637db44 JC |
360 | |
361 | static struct attribute *iio_trigger_consumer_attrs[] = { | |
362 | &dev_attr_current_trigger.attr, | |
363 | NULL, | |
364 | }; | |
365 | ||
366 | static const struct attribute_group iio_trigger_consumer_attr_group = { | |
367 | .name = "trigger", | |
368 | .attrs = iio_trigger_consumer_attrs, | |
369 | }; | |
370 | ||
371 | static void iio_trig_release(struct device *device) | |
372 | { | |
373 | struct iio_trigger *trig = to_iio_trigger(device); | |
d96d1337 JC |
374 | int i; |
375 | ||
376 | if (trig->subirq_base) { | |
377 | for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) { | |
378 | irq_modify_status(trig->subirq_base + i, | |
379 | IRQ_NOAUTOEN, | |
380 | IRQ_NOREQUEST | IRQ_NOPROBE); | |
381 | irq_set_chip(trig->subirq_base + i, | |
382 | NULL); | |
383 | irq_set_handler(trig->subirq_base + i, | |
384 | NULL); | |
385 | } | |
386 | ||
387 | irq_free_descs(trig->subirq_base, | |
388 | CONFIG_IIO_CONSUMERS_PER_TRIGGER); | |
389 | } | |
59c85e82 | 390 | kfree(trig->name); |
1637db44 | 391 | kfree(trig); |
1637db44 JC |
392 | } |
393 | ||
394 | static struct device_type iio_trig_type = { | |
395 | .release = iio_trig_release, | |
6d459aa0 | 396 | .groups = iio_trig_attr_groups, |
1637db44 JC |
397 | }; |
398 | ||
d96d1337 JC |
399 | static void iio_trig_subirqmask(struct irq_data *d) |
400 | { | |
401 | struct irq_chip *chip = irq_data_get_irq_chip(d); | |
402 | struct iio_trigger *trig | |
403 | = container_of(chip, | |
404 | struct iio_trigger, subirq_chip); | |
405 | trig->subirqs[d->irq - trig->subirq_base].enabled = false; | |
406 | } | |
407 | ||
408 | static void iio_trig_subirqunmask(struct irq_data *d) | |
409 | { | |
410 | struct irq_chip *chip = irq_data_get_irq_chip(d); | |
411 | struct iio_trigger *trig | |
412 | = container_of(chip, | |
413 | struct iio_trigger, subirq_chip); | |
414 | trig->subirqs[d->irq - trig->subirq_base].enabled = true; | |
415 | } | |
416 | ||
7cbb7537 | 417 | struct iio_trigger *iio_trigger_alloc(const char *fmt, ...) |
1637db44 | 418 | { |
59c85e82 | 419 | va_list vargs; |
1637db44 JC |
420 | struct iio_trigger *trig; |
421 | trig = kzalloc(sizeof *trig, GFP_KERNEL); | |
422 | if (trig) { | |
d96d1337 | 423 | int i; |
1637db44 | 424 | trig->dev.type = &iio_trig_type; |
5aaaeba8 | 425 | trig->dev.bus = &iio_bus_type; |
1637db44 | 426 | device_initialize(&trig->dev); |
d96d1337 | 427 | |
59c85e82 JC |
428 | mutex_init(&trig->pool_lock); |
429 | trig->subirq_base | |
430 | = irq_alloc_descs(-1, 0, | |
431 | CONFIG_IIO_CONSUMERS_PER_TRIGGER, | |
432 | 0); | |
433 | if (trig->subirq_base < 0) { | |
434 | kfree(trig); | |
435 | return NULL; | |
436 | } | |
437 | va_start(vargs, fmt); | |
438 | trig->name = kvasprintf(GFP_KERNEL, fmt, vargs); | |
439 | va_end(vargs); | |
440 | if (trig->name == NULL) { | |
441 | irq_free_descs(trig->subirq_base, | |
442 | CONFIG_IIO_CONSUMERS_PER_TRIGGER); | |
443 | kfree(trig); | |
444 | return NULL; | |
445 | } | |
446 | trig->subirq_chip.name = trig->name; | |
447 | trig->subirq_chip.irq_mask = &iio_trig_subirqmask; | |
448 | trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask; | |
449 | for (i = 0; i < CONFIG_IIO_CONSUMERS_PER_TRIGGER; i++) { | |
450 | irq_set_chip(trig->subirq_base + i, | |
451 | &trig->subirq_chip); | |
452 | irq_set_handler(trig->subirq_base + i, | |
453 | &handle_simple_irq); | |
454 | irq_modify_status(trig->subirq_base + i, | |
455 | IRQ_NOREQUEST | IRQ_NOAUTOEN, | |
456 | IRQ_NOPROBE); | |
d96d1337 | 457 | } |
5f9c035c | 458 | get_device(&trig->dev); |
1637db44 JC |
459 | } |
460 | return trig; | |
461 | } | |
7cbb7537 | 462 | EXPORT_SYMBOL(iio_trigger_alloc); |
1637db44 | 463 | |
7cbb7537 | 464 | void iio_trigger_free(struct iio_trigger *trig) |
1637db44 JC |
465 | { |
466 | if (trig) | |
467 | put_device(&trig->dev); | |
468 | } | |
7cbb7537 | 469 | EXPORT_SYMBOL(iio_trigger_free); |
1637db44 | 470 | |
67be8e32 | 471 | void iio_device_register_trigger_consumer(struct iio_dev *indio_dev) |
1637db44 | 472 | { |
f8c6f4e9 | 473 | indio_dev->groups[indio_dev->groupcounter++] = |
26d25ae3 | 474 | &iio_trigger_consumer_attr_group; |
1637db44 | 475 | } |
1637db44 | 476 | |
f8c6f4e9 | 477 | void iio_device_unregister_trigger_consumer(struct iio_dev *indio_dev) |
1637db44 | 478 | { |
860c9c54 | 479 | /* Clean up an associated but not attached trigger reference */ |
f8c6f4e9 | 480 | if (indio_dev->trig) |
7cbb7537 | 481 | iio_trigger_put(indio_dev->trig); |
1637db44 | 482 | } |
1637db44 | 483 | |
3b99fb76 | 484 | int iio_triggered_buffer_postenable(struct iio_dev *indio_dev) |
c3db00cc | 485 | { |
67be8e32 JC |
486 | return iio_trigger_attach_poll_func(indio_dev->trig, |
487 | indio_dev->pollfunc); | |
c3db00cc | 488 | } |
3b99fb76 | 489 | EXPORT_SYMBOL(iio_triggered_buffer_postenable); |
c3db00cc | 490 | |
3b99fb76 | 491 | int iio_triggered_buffer_predisable(struct iio_dev *indio_dev) |
c3db00cc | 492 | { |
034bd7b5 | 493 | return iio_trigger_detach_poll_func(indio_dev->trig, |
67be8e32 | 494 | indio_dev->pollfunc); |
c3db00cc | 495 | } |
3b99fb76 | 496 | EXPORT_SYMBOL(iio_triggered_buffer_predisable); |