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7026ea4b JC |
1 | /* The industrial I/O core |
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 | * Handling of ring allocation / resizing. | |
10 | * | |
11 | * | |
12 | * Things to look at here. | |
13 | * - Better memory allocation techniques? | |
14 | * - Alternative access techniques? | |
15 | */ | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/device.h> | |
18 | #include <linux/interrupt.h> | |
19 | #include <linux/fs.h> | |
20 | #include <linux/poll.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/cdev.h> | |
23 | #include <linux/idr.h> | |
24 | ||
25 | #include "iio.h" | |
26 | #include "ring_generic.h" | |
27 | ||
28 | /* IDR for ring buffer identifier */ | |
29 | static DEFINE_IDR(iio_ring_idr); | |
30 | /* IDR for ring event identifier */ | |
31 | static DEFINE_IDR(iio_ring_event_idr); | |
32 | /* IDR for ring access identifier */ | |
33 | static DEFINE_IDR(iio_ring_access_idr); | |
34 | ||
35 | int iio_push_ring_event(struct iio_ring_buffer *ring_buf, | |
36 | int event_code, | |
37 | s64 timestamp) | |
38 | { | |
39 | return __iio_push_event(&ring_buf->ev_int, | |
40 | event_code, | |
41 | timestamp, | |
42 | &ring_buf->shared_ev_pointer); | |
43 | } | |
44 | EXPORT_SYMBOL(iio_push_ring_event); | |
45 | ||
46 | int iio_push_or_escallate_ring_event(struct iio_ring_buffer *ring_buf, | |
47 | int event_code, | |
48 | s64 timestamp) | |
49 | { | |
50 | if (ring_buf->shared_ev_pointer.ev_p) | |
51 | __iio_change_event(ring_buf->shared_ev_pointer.ev_p, | |
52 | event_code, | |
53 | timestamp); | |
54 | else | |
55 | return iio_push_ring_event(ring_buf, | |
56 | event_code, | |
57 | timestamp); | |
58 | return 0; | |
59 | } | |
60 | EXPORT_SYMBOL(iio_push_or_escallate_ring_event); | |
61 | ||
62 | /** | |
63 | * iio_ring_open() chrdev file open for ring buffer access | |
64 | * | |
65 | * This function relies on all ring buffer implementations having an | |
66 | * iio_ring_buffer as their first element. | |
67 | **/ | |
68 | int iio_ring_open(struct inode *inode, struct file *filp) | |
69 | { | |
70 | struct iio_handler *hand | |
71 | = container_of(inode->i_cdev, struct iio_handler, chrdev); | |
72 | struct iio_ring_buffer *rb = hand->private; | |
73 | ||
74 | filp->private_data = hand->private; | |
75 | if (rb->access.mark_in_use) | |
76 | rb->access.mark_in_use(rb); | |
77 | ||
78 | return 0; | |
79 | } | |
80 | ||
81 | /** | |
82 | * iio_ring_release() -chrdev file close ring buffer access | |
83 | * | |
84 | * This function relies on all ring buffer implementations having an | |
85 | * iio_ring_buffer as their first element. | |
86 | **/ | |
87 | int iio_ring_release(struct inode *inode, struct file *filp) | |
88 | { | |
89 | struct cdev *cd = inode->i_cdev; | |
90 | struct iio_handler *hand = iio_cdev_to_handler(cd); | |
91 | struct iio_ring_buffer *rb = hand->private; | |
92 | ||
93 | clear_bit(IIO_BUSY_BIT_POS, &rb->access_handler.flags); | |
94 | if (rb->access.unmark_in_use) | |
95 | rb->access.unmark_in_use(rb); | |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
100 | /** | |
101 | * iio_ring_rip_outer() chrdev read for ring buffer access | |
102 | * | |
103 | * This function relies on all ring buffer implementations having an | |
104 | * iio_ring _bufer as their first element. | |
105 | **/ | |
106 | ssize_t iio_ring_rip_outer(struct file *filp, | |
107 | char *buf, | |
108 | size_t count, | |
109 | loff_t *f_ps) | |
110 | { | |
111 | struct iio_ring_buffer *rb = filp->private_data; | |
112 | int ret, dead_offset, copied; | |
113 | u8 *data; | |
114 | /* rip lots must exist. */ | |
115 | if (!rb->access.rip_lots) | |
116 | return -EINVAL; | |
117 | copied = rb->access.rip_lots(rb, count, &data, &dead_offset); | |
118 | ||
119 | if (copied < 0) { | |
120 | ret = copied; | |
121 | goto error_ret; | |
122 | } | |
123 | if (copy_to_user(buf, data + dead_offset, copied)) { | |
124 | ret = -EFAULT; | |
125 | goto error_free_data_cpy; | |
126 | } | |
127 | /* In clever ring buffer designs this may not need to be freed. | |
128 | * When such a design exists I'll add this to ring access funcs. | |
129 | */ | |
130 | kfree(data); | |
131 | ||
132 | return copied; | |
133 | ||
134 | error_free_data_cpy: | |
135 | kfree(data); | |
136 | error_ret: | |
137 | return ret; | |
138 | } | |
139 | ||
140 | static const struct file_operations iio_ring_fileops = { | |
141 | .read = iio_ring_rip_outer, | |
142 | .release = iio_ring_release, | |
143 | .open = iio_ring_open, | |
144 | .owner = THIS_MODULE, | |
145 | }; | |
146 | ||
147 | /** | |
148 | * __iio_request_ring_buffer_event_chrdev() allocate ring event chrdev | |
149 | * @buf: ring buffer whose event chrdev we are allocating | |
150 | * @owner: the module who owns the ring buffer (for ref counting) | |
151 | * @dev: device with which the chrdev is associated | |
152 | **/ | |
153 | static inline int | |
154 | __iio_request_ring_buffer_event_chrdev(struct iio_ring_buffer *buf, | |
155 | int id, | |
156 | struct module *owner, | |
157 | struct device *dev) | |
158 | { | |
159 | int ret; | |
160 | ret = iio_get_new_idr_val(&iio_ring_event_idr); | |
161 | if (ret < 0) | |
162 | goto error_ret; | |
163 | else | |
164 | buf->ev_int.id = ret; | |
165 | ||
166 | snprintf(buf->ev_int._name, 20, | |
167 | "ring_event_line%d", | |
168 | buf->ev_int.id); | |
169 | ret = iio_setup_ev_int(&(buf->ev_int), | |
170 | buf->ev_int._name, | |
171 | owner, | |
172 | dev); | |
173 | if (ret) | |
174 | goto error_free_id; | |
175 | return 0; | |
176 | ||
177 | error_free_id: | |
178 | iio_free_idr_val(&iio_ring_event_idr, buf->ev_int.id); | |
179 | error_ret: | |
180 | return ret; | |
181 | } | |
182 | ||
183 | static inline void | |
184 | __iio_free_ring_buffer_event_chrdev(struct iio_ring_buffer *buf) | |
185 | { | |
186 | iio_free_ev_int(&(buf->ev_int)); | |
187 | iio_free_idr_val(&iio_ring_event_idr, buf->ev_int.id); | |
188 | } | |
189 | ||
190 | static void iio_ring_access_release(struct device *dev) | |
191 | { | |
192 | struct iio_ring_buffer *buf | |
193 | = access_dev_to_iio_ring_buffer(dev); | |
194 | cdev_del(&buf->access_handler.chrdev); | |
195 | iio_device_free_chrdev_minor(MINOR(dev->devt)); | |
196 | } | |
197 | ||
198 | static struct device_type iio_ring_access_type = { | |
199 | .release = iio_ring_access_release, | |
200 | }; | |
201 | ||
202 | static inline int | |
203 | __iio_request_ring_buffer_access_chrdev(struct iio_ring_buffer *buf, | |
204 | int id, | |
205 | struct module *owner) | |
206 | { | |
207 | int ret, minor; | |
208 | ||
209 | buf->access_handler.flags = 0; | |
210 | ||
211 | buf->access_dev.parent = &buf->dev; | |
212 | buf->access_dev.class = &iio_class; | |
213 | buf->access_dev.type = &iio_ring_access_type; | |
214 | device_initialize(&buf->access_dev); | |
215 | ||
216 | minor = iio_device_get_chrdev_minor(); | |
217 | if (minor < 0) { | |
218 | ret = minor; | |
219 | goto error_device_put; | |
220 | } | |
221 | buf->access_dev.devt = MKDEV(MAJOR(iio_devt), minor); | |
222 | ||
223 | ret = iio_get_new_idr_val(&iio_ring_access_idr); | |
224 | if (ret < 0) | |
225 | goto error_device_put; | |
226 | else | |
227 | buf->access_id = ret; | |
228 | dev_set_name(&buf->access_dev, "ring_access%d", buf->access_id); | |
229 | ret = device_add(&buf->access_dev); | |
230 | if (ret < 0) { | |
231 | printk(KERN_ERR "failed to add the ring access dev\n"); | |
232 | goto error_free_idr; | |
233 | } | |
234 | ||
235 | cdev_init(&buf->access_handler.chrdev, &iio_ring_fileops); | |
236 | buf->access_handler.chrdev.owner = owner; | |
237 | ||
238 | ret = cdev_add(&buf->access_handler.chrdev, buf->access_dev.devt, 1); | |
239 | if (ret) { | |
240 | printk(KERN_ERR "failed to allocate ring access chrdev\n"); | |
241 | goto error_device_unregister; | |
242 | } | |
243 | return 0; | |
244 | error_device_unregister: | |
245 | device_unregister(&buf->access_dev); | |
246 | error_free_idr: | |
247 | iio_free_idr_val(&iio_ring_access_idr, buf->access_id); | |
248 | error_device_put: | |
249 | put_device(&buf->access_dev); | |
250 | ||
251 | return ret; | |
252 | } | |
253 | ||
254 | static void __iio_free_ring_buffer_access_chrdev(struct iio_ring_buffer *buf) | |
255 | { | |
256 | iio_free_idr_val(&iio_ring_access_idr, buf->access_id); | |
257 | device_unregister(&buf->access_dev); | |
258 | } | |
259 | ||
260 | void iio_ring_buffer_init(struct iio_ring_buffer *ring, | |
261 | struct iio_dev *dev_info) | |
262 | { | |
263 | if (ring->access.mark_param_change) | |
264 | ring->access.mark_param_change(ring); | |
265 | ring->indio_dev = dev_info; | |
266 | ring->ev_int.private = ring; | |
267 | ring->access_handler.private = ring; | |
268 | } | |
269 | EXPORT_SYMBOL(iio_ring_buffer_init); | |
270 | ||
271 | int iio_ring_buffer_register(struct iio_ring_buffer *ring) | |
272 | { | |
273 | int ret; | |
274 | ret = iio_get_new_idr_val(&iio_ring_idr); | |
275 | if (ret < 0) | |
276 | goto error_ret; | |
277 | else | |
278 | ring->id = ret; | |
279 | ||
280 | dev_set_name(&ring->dev, "ring_buffer%d", ring->id); | |
281 | ret = device_add(&ring->dev); | |
282 | if (ret) | |
283 | goto error_free_id; | |
284 | ||
285 | ret = __iio_request_ring_buffer_event_chrdev(ring, | |
286 | 0, | |
287 | ring->owner, | |
288 | &ring->dev); | |
289 | if (ret) | |
290 | goto error_remove_device; | |
291 | ||
292 | ret = __iio_request_ring_buffer_access_chrdev(ring, | |
293 | 0, | |
294 | ring->owner); | |
295 | ||
296 | if (ret) | |
297 | goto error_free_ring_buffer_event_chrdev; | |
298 | ||
299 | return ret; | |
300 | error_free_ring_buffer_event_chrdev: | |
301 | __iio_free_ring_buffer_event_chrdev(ring); | |
302 | error_remove_device: | |
303 | device_del(&ring->dev); | |
304 | error_free_id: | |
305 | iio_free_idr_val(&iio_ring_idr, ring->id); | |
306 | error_ret: | |
307 | return ret; | |
308 | } | |
309 | EXPORT_SYMBOL(iio_ring_buffer_register); | |
310 | ||
311 | void iio_ring_buffer_unregister(struct iio_ring_buffer *ring) | |
312 | { | |
313 | __iio_free_ring_buffer_access_chrdev(ring); | |
314 | __iio_free_ring_buffer_event_chrdev(ring); | |
315 | device_del(&ring->dev); | |
316 | iio_free_idr_val(&iio_ring_idr, ring->id); | |
317 | } | |
318 | EXPORT_SYMBOL(iio_ring_buffer_unregister); | |
319 | ||
320 | ssize_t iio_read_ring_length(struct device *dev, | |
321 | struct device_attribute *attr, | |
322 | char *buf) | |
323 | { | |
324 | int len = 0; | |
325 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
326 | ||
327 | if (ring->access.get_length) | |
328 | len = sprintf(buf, "%d\n", | |
329 | ring->access.get_length(ring)); | |
330 | ||
331 | return len; | |
332 | } | |
333 | EXPORT_SYMBOL(iio_read_ring_length); | |
334 | ||
335 | ssize_t iio_write_ring_length(struct device *dev, | |
336 | struct device_attribute *attr, | |
337 | const char *buf, | |
338 | size_t len) | |
339 | { | |
340 | int ret; | |
341 | ulong val; | |
342 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
343 | ret = strict_strtoul(buf, 10, &val); | |
344 | if (ret) | |
345 | return ret; | |
346 | ||
347 | if (ring->access.get_length) | |
348 | if (val == ring->access.get_length(ring)) | |
349 | return len; | |
350 | ||
351 | if (ring->access.set_length) { | |
352 | ring->access.set_length(ring, val); | |
353 | if (ring->access.mark_param_change) | |
354 | ring->access.mark_param_change(ring); | |
355 | } | |
356 | ||
357 | return len; | |
358 | } | |
359 | EXPORT_SYMBOL(iio_write_ring_length); | |
360 | ||
361 | ssize_t iio_read_ring_bps(struct device *dev, | |
362 | struct device_attribute *attr, | |
363 | char *buf) | |
364 | { | |
365 | int len = 0; | |
366 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
367 | ||
368 | if (ring->access.get_bpd) | |
369 | len = sprintf(buf, "%d\n", | |
370 | ring->access.get_bpd(ring)); | |
371 | ||
372 | return len; | |
373 | } | |
374 | EXPORT_SYMBOL(iio_read_ring_bps); | |
375 | ||
376 | ssize_t iio_store_ring_enable(struct device *dev, | |
377 | struct device_attribute *attr, | |
378 | const char *buf, | |
379 | size_t len) | |
380 | { | |
381 | int ret; | |
382 | bool requested_state, current_state; | |
383 | int previous_mode; | |
384 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
385 | struct iio_dev *dev_info = ring->indio_dev; | |
386 | ||
387 | mutex_lock(&dev_info->mlock); | |
388 | previous_mode = dev_info->currentmode; | |
389 | requested_state = !(buf[0] == '0'); | |
390 | current_state = !!(previous_mode & INDIO_ALL_RING_MODES); | |
391 | if (current_state == requested_state) { | |
392 | printk(KERN_INFO "iio-ring, current state requested again\n"); | |
393 | goto done; | |
394 | } | |
395 | if (requested_state) { | |
396 | if (ring->preenable) { | |
397 | ret = ring->preenable(dev_info); | |
398 | if (ret) { | |
399 | printk(KERN_ERR | |
400 | "Buffer not started:" | |
401 | "ring preenable failed\n"); | |
402 | goto error_ret; | |
403 | } | |
404 | } | |
405 | if (ring->access.request_update) { | |
406 | ret = ring->access.request_update(ring); | |
407 | if (ret) { | |
408 | printk(KERN_INFO | |
409 | "Buffer not started:" | |
410 | "ring parameter update failed\n"); | |
411 | goto error_ret; | |
412 | } | |
413 | } | |
414 | if (ring->access.mark_in_use) | |
415 | ring->access.mark_in_use(ring); | |
416 | /* Definitely possible for devices to support both of these.*/ | |
417 | if (dev_info->modes & INDIO_RING_TRIGGERED) { | |
418 | if (!dev_info->trig) { | |
419 | printk(KERN_INFO | |
420 | "Buffer not started: no trigger\n"); | |
421 | ret = -EINVAL; | |
422 | if (ring->access.unmark_in_use) | |
423 | ring->access.unmark_in_use(ring); | |
424 | goto error_ret; | |
425 | } | |
426 | dev_info->currentmode = INDIO_RING_TRIGGERED; | |
427 | } else if (dev_info->modes & INDIO_RING_HARDWARE_BUFFER) | |
428 | dev_info->currentmode = INDIO_RING_HARDWARE_BUFFER; | |
429 | else { /* should never be reached */ | |
430 | ret = -EINVAL; | |
431 | goto error_ret; | |
432 | } | |
433 | ||
434 | if (ring->postenable) { | |
435 | ||
436 | ret = ring->postenable(dev_info); | |
437 | if (ret) { | |
438 | printk(KERN_INFO | |
439 | "Buffer not started:" | |
440 | "postenable failed\n"); | |
441 | if (ring->access.unmark_in_use) | |
442 | ring->access.unmark_in_use(ring); | |
443 | dev_info->currentmode = previous_mode; | |
444 | if (ring->postdisable) | |
445 | ring->postdisable(dev_info); | |
446 | goto error_ret; | |
447 | } | |
448 | } | |
449 | } else { | |
450 | if (ring->predisable) { | |
451 | ret = ring->predisable(dev_info); | |
452 | if (ret) | |
453 | goto error_ret; | |
454 | } | |
455 | if (ring->access.unmark_in_use) | |
456 | ring->access.unmark_in_use(ring); | |
457 | dev_info->currentmode = INDIO_DIRECT_MODE; | |
458 | if (ring->postdisable) { | |
459 | ret = ring->postdisable(dev_info); | |
460 | if (ret) | |
461 | goto error_ret; | |
462 | } | |
463 | } | |
464 | done: | |
465 | mutex_unlock(&dev_info->mlock); | |
466 | return len; | |
467 | ||
468 | error_ret: | |
469 | mutex_unlock(&dev_info->mlock); | |
470 | return ret; | |
471 | } | |
472 | EXPORT_SYMBOL(iio_store_ring_enable); | |
473 | ssize_t iio_show_ring_enable(struct device *dev, | |
474 | struct device_attribute *attr, | |
475 | char *buf) | |
476 | { | |
477 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
478 | return sprintf(buf, "%d\n", !!(ring->indio_dev->currentmode | |
479 | & INDIO_ALL_RING_MODES)); | |
480 | } | |
481 | EXPORT_SYMBOL(iio_show_ring_enable); | |
482 | ||
483 | ssize_t iio_scan_el_show(struct device *dev, | |
484 | struct device_attribute *attr, | |
485 | char *buf) | |
486 | { | |
487 | int ret; | |
488 | struct iio_dev *indio_dev = dev_get_drvdata(dev); | |
489 | struct iio_scan_el *this_el = to_iio_scan_el(attr); | |
490 | ||
491 | ret = iio_scan_mask_query(indio_dev, this_el->number); | |
492 | if (ret < 0) | |
493 | return ret; | |
494 | return sprintf(buf, "%d\n", ret); | |
495 | } | |
496 | EXPORT_SYMBOL(iio_scan_el_show); | |
497 | ||
498 | ssize_t iio_scan_el_store(struct device *dev, | |
499 | struct device_attribute *attr, | |
500 | const char *buf, | |
501 | size_t len) | |
502 | { | |
503 | int ret = 0; | |
504 | bool state; | |
505 | struct iio_dev *indio_dev = dev_get_drvdata(dev); | |
506 | struct iio_scan_el *this_el = to_iio_scan_el(attr); | |
507 | ||
508 | state = !(buf[0] == '0'); | |
509 | mutex_lock(&indio_dev->mlock); | |
510 | if (indio_dev->currentmode == INDIO_RING_TRIGGERED) { | |
511 | ret = -EBUSY; | |
512 | goto error_ret; | |
513 | } | |
514 | ret = iio_scan_mask_query(indio_dev, this_el->number); | |
515 | if (ret < 0) | |
516 | goto error_ret; | |
517 | if (!state && ret) { | |
518 | ret = iio_scan_mask_clear(indio_dev, this_el->number); | |
519 | if (ret) | |
520 | goto error_ret; | |
521 | indio_dev->scan_count--; | |
522 | } else if (state && !ret) { | |
523 | ret = iio_scan_mask_set(indio_dev, this_el->number); | |
524 | if (ret) | |
525 | goto error_ret; | |
526 | indio_dev->scan_count++; | |
527 | } | |
528 | if (this_el->set_state) | |
529 | ret = this_el->set_state(this_el, indio_dev, state); | |
530 | error_ret: | |
531 | mutex_unlock(&indio_dev->mlock); | |
532 | ||
533 | return ret ? ret : len; | |
534 | ||
535 | } | |
536 | EXPORT_SYMBOL(iio_scan_el_store); | |
537 | ||
538 | ssize_t iio_scan_el_ts_show(struct device *dev, | |
539 | struct device_attribute *attr, | |
540 | char *buf) | |
541 | { | |
542 | struct iio_dev *indio_dev = dev_get_drvdata(dev); | |
543 | return sprintf(buf, "%d\n", indio_dev->scan_timestamp); | |
544 | } | |
545 | EXPORT_SYMBOL(iio_scan_el_ts_show); | |
546 | ||
547 | ssize_t iio_scan_el_ts_store(struct device *dev, | |
548 | struct device_attribute *attr, | |
549 | const char *buf, | |
550 | size_t len) | |
551 | { | |
552 | int ret = 0; | |
553 | struct iio_dev *indio_dev = dev_get_drvdata(dev); | |
554 | bool state; | |
555 | state = !(buf[0] == '0'); | |
556 | mutex_lock(&indio_dev->mlock); | |
557 | if (indio_dev->currentmode == INDIO_RING_TRIGGERED) { | |
558 | ret = -EBUSY; | |
559 | goto error_ret; | |
560 | } | |
561 | indio_dev->scan_timestamp = state; | |
562 | error_ret: | |
563 | mutex_unlock(&indio_dev->mlock); | |
564 | ||
565 | return ret ? ret : len; | |
566 | } | |
567 | EXPORT_SYMBOL(iio_scan_el_ts_store); | |
568 |