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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> | |
5a0e3ad6 | 23 | #include <linux/slab.h> |
7026ea4b JC |
24 | |
25 | #include "iio.h" | |
26 | #include "ring_generic.h" | |
27 | ||
7026ea4b JC |
28 | int iio_push_ring_event(struct iio_ring_buffer *ring_buf, |
29 | int event_code, | |
30 | s64 timestamp) | |
31 | { | |
32 | return __iio_push_event(&ring_buf->ev_int, | |
33 | event_code, | |
34 | timestamp, | |
35 | &ring_buf->shared_ev_pointer); | |
36 | } | |
37 | EXPORT_SYMBOL(iio_push_ring_event); | |
38 | ||
39 | int iio_push_or_escallate_ring_event(struct iio_ring_buffer *ring_buf, | |
40 | int event_code, | |
41 | s64 timestamp) | |
42 | { | |
43 | if (ring_buf->shared_ev_pointer.ev_p) | |
44 | __iio_change_event(ring_buf->shared_ev_pointer.ev_p, | |
45 | event_code, | |
46 | timestamp); | |
47 | else | |
48 | return iio_push_ring_event(ring_buf, | |
49 | event_code, | |
50 | timestamp); | |
51 | return 0; | |
52 | } | |
53 | EXPORT_SYMBOL(iio_push_or_escallate_ring_event); | |
54 | ||
55 | /** | |
56 | * iio_ring_open() chrdev file open for ring buffer access | |
57 | * | |
58 | * This function relies on all ring buffer implementations having an | |
59 | * iio_ring_buffer as their first element. | |
60 | **/ | |
0deebb4f | 61 | static int iio_ring_open(struct inode *inode, struct file *filp) |
7026ea4b JC |
62 | { |
63 | struct iio_handler *hand | |
64 | = container_of(inode->i_cdev, struct iio_handler, chrdev); | |
65 | struct iio_ring_buffer *rb = hand->private; | |
66 | ||
67 | filp->private_data = hand->private; | |
68 | if (rb->access.mark_in_use) | |
69 | rb->access.mark_in_use(rb); | |
70 | ||
71 | return 0; | |
72 | } | |
73 | ||
74 | /** | |
75 | * iio_ring_release() -chrdev file close ring buffer access | |
76 | * | |
77 | * This function relies on all ring buffer implementations having an | |
78 | * iio_ring_buffer as their first element. | |
79 | **/ | |
0deebb4f | 80 | static int iio_ring_release(struct inode *inode, struct file *filp) |
7026ea4b JC |
81 | { |
82 | struct cdev *cd = inode->i_cdev; | |
83 | struct iio_handler *hand = iio_cdev_to_handler(cd); | |
84 | struct iio_ring_buffer *rb = hand->private; | |
85 | ||
86 | clear_bit(IIO_BUSY_BIT_POS, &rb->access_handler.flags); | |
87 | if (rb->access.unmark_in_use) | |
88 | rb->access.unmark_in_use(rb); | |
89 | ||
90 | return 0; | |
91 | } | |
92 | ||
93 | /** | |
94 | * iio_ring_rip_outer() chrdev read for ring buffer access | |
95 | * | |
96 | * This function relies on all ring buffer implementations having an | |
97 | * iio_ring _bufer as their first element. | |
98 | **/ | |
0deebb4f GKH |
99 | static ssize_t iio_ring_rip_outer(struct file *filp, char __user *buf, |
100 | size_t count, loff_t *f_ps) | |
7026ea4b JC |
101 | { |
102 | struct iio_ring_buffer *rb = filp->private_data; | |
103 | int ret, dead_offset, copied; | |
104 | u8 *data; | |
105 | /* rip lots must exist. */ | |
106 | if (!rb->access.rip_lots) | |
107 | return -EINVAL; | |
108 | copied = rb->access.rip_lots(rb, count, &data, &dead_offset); | |
109 | ||
110 | if (copied < 0) { | |
111 | ret = copied; | |
112 | goto error_ret; | |
113 | } | |
114 | if (copy_to_user(buf, data + dead_offset, copied)) { | |
115 | ret = -EFAULT; | |
116 | goto error_free_data_cpy; | |
117 | } | |
118 | /* In clever ring buffer designs this may not need to be freed. | |
119 | * When such a design exists I'll add this to ring access funcs. | |
120 | */ | |
121 | kfree(data); | |
122 | ||
123 | return copied; | |
124 | ||
125 | error_free_data_cpy: | |
126 | kfree(data); | |
127 | error_ret: | |
128 | return ret; | |
129 | } | |
130 | ||
131 | static const struct file_operations iio_ring_fileops = { | |
132 | .read = iio_ring_rip_outer, | |
133 | .release = iio_ring_release, | |
134 | .open = iio_ring_open, | |
135 | .owner = THIS_MODULE, | |
136 | }; | |
137 | ||
138 | /** | |
139 | * __iio_request_ring_buffer_event_chrdev() allocate ring event chrdev | |
140 | * @buf: ring buffer whose event chrdev we are allocating | |
141 | * @owner: the module who owns the ring buffer (for ref counting) | |
142 | * @dev: device with which the chrdev is associated | |
143 | **/ | |
144 | static inline int | |
145 | __iio_request_ring_buffer_event_chrdev(struct iio_ring_buffer *buf, | |
146 | int id, | |
147 | struct module *owner, | |
148 | struct device *dev) | |
149 | { | |
150 | int ret; | |
758d988c JC |
151 | |
152 | buf->ev_int.id = id; | |
7026ea4b | 153 | |
ba5c6fba JC |
154 | snprintf(buf->ev_int._name, sizeof(buf->ev_int._name), |
155 | "%s:event%d", | |
156 | dev_name(&buf->dev), | |
7026ea4b JC |
157 | buf->ev_int.id); |
158 | ret = iio_setup_ev_int(&(buf->ev_int), | |
159 | buf->ev_int._name, | |
160 | owner, | |
161 | dev); | |
162 | if (ret) | |
758d988c | 163 | goto error_ret; |
7026ea4b JC |
164 | return 0; |
165 | ||
7026ea4b JC |
166 | error_ret: |
167 | return ret; | |
168 | } | |
169 | ||
170 | static inline void | |
171 | __iio_free_ring_buffer_event_chrdev(struct iio_ring_buffer *buf) | |
172 | { | |
173 | iio_free_ev_int(&(buf->ev_int)); | |
7026ea4b JC |
174 | } |
175 | ||
176 | static void iio_ring_access_release(struct device *dev) | |
177 | { | |
178 | struct iio_ring_buffer *buf | |
179 | = access_dev_to_iio_ring_buffer(dev); | |
180 | cdev_del(&buf->access_handler.chrdev); | |
181 | iio_device_free_chrdev_minor(MINOR(dev->devt)); | |
182 | } | |
183 | ||
184 | static struct device_type iio_ring_access_type = { | |
185 | .release = iio_ring_access_release, | |
186 | }; | |
187 | ||
188 | static inline int | |
189 | __iio_request_ring_buffer_access_chrdev(struct iio_ring_buffer *buf, | |
190 | int id, | |
191 | struct module *owner) | |
192 | { | |
193 | int ret, minor; | |
194 | ||
195 | buf->access_handler.flags = 0; | |
196 | ||
197 | buf->access_dev.parent = &buf->dev; | |
5aaaeba8 | 198 | buf->access_dev.bus = &iio_bus_type; |
7026ea4b JC |
199 | buf->access_dev.type = &iio_ring_access_type; |
200 | device_initialize(&buf->access_dev); | |
201 | ||
202 | minor = iio_device_get_chrdev_minor(); | |
203 | if (minor < 0) { | |
204 | ret = minor; | |
205 | goto error_device_put; | |
206 | } | |
207 | buf->access_dev.devt = MKDEV(MAJOR(iio_devt), minor); | |
208 | ||
758d988c JC |
209 | |
210 | buf->access_id = id; | |
211 | ||
ba5c6fba JC |
212 | dev_set_name(&buf->access_dev, "%s:access%d", |
213 | dev_name(&buf->dev), | |
214 | buf->access_id); | |
7026ea4b JC |
215 | ret = device_add(&buf->access_dev); |
216 | if (ret < 0) { | |
217 | printk(KERN_ERR "failed to add the ring access dev\n"); | |
758d988c | 218 | goto error_device_put; |
7026ea4b JC |
219 | } |
220 | ||
221 | cdev_init(&buf->access_handler.chrdev, &iio_ring_fileops); | |
222 | buf->access_handler.chrdev.owner = owner; | |
223 | ||
224 | ret = cdev_add(&buf->access_handler.chrdev, buf->access_dev.devt, 1); | |
225 | if (ret) { | |
226 | printk(KERN_ERR "failed to allocate ring access chrdev\n"); | |
227 | goto error_device_unregister; | |
228 | } | |
229 | return 0; | |
758d988c | 230 | |
7026ea4b JC |
231 | error_device_unregister: |
232 | device_unregister(&buf->access_dev); | |
7026ea4b JC |
233 | error_device_put: |
234 | put_device(&buf->access_dev); | |
235 | ||
236 | return ret; | |
237 | } | |
238 | ||
239 | static void __iio_free_ring_buffer_access_chrdev(struct iio_ring_buffer *buf) | |
240 | { | |
7026ea4b JC |
241 | device_unregister(&buf->access_dev); |
242 | } | |
243 | ||
244 | void iio_ring_buffer_init(struct iio_ring_buffer *ring, | |
245 | struct iio_dev *dev_info) | |
246 | { | |
247 | if (ring->access.mark_param_change) | |
248 | ring->access.mark_param_change(ring); | |
249 | ring->indio_dev = dev_info; | |
250 | ring->ev_int.private = ring; | |
251 | ring->access_handler.private = ring; | |
0deebb4f | 252 | ring->shared_ev_pointer.ev_p = NULL; |
6f2dfb31 | 253 | spin_lock_init(&ring->shared_ev_pointer.lock); |
7026ea4b JC |
254 | } |
255 | EXPORT_SYMBOL(iio_ring_buffer_init); | |
256 | ||
758d988c | 257 | int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id) |
7026ea4b JC |
258 | { |
259 | int ret; | |
758d988c JC |
260 | |
261 | ring->id = id; | |
7026ea4b | 262 | |
ba5c6fba JC |
263 | dev_set_name(&ring->dev, "%s:buffer%d", |
264 | dev_name(ring->dev.parent), | |
265 | ring->id); | |
7026ea4b JC |
266 | ret = device_add(&ring->dev); |
267 | if (ret) | |
758d988c | 268 | goto error_ret; |
7026ea4b JC |
269 | |
270 | ret = __iio_request_ring_buffer_event_chrdev(ring, | |
271 | 0, | |
272 | ring->owner, | |
273 | &ring->dev); | |
274 | if (ret) | |
275 | goto error_remove_device; | |
276 | ||
277 | ret = __iio_request_ring_buffer_access_chrdev(ring, | |
278 | 0, | |
279 | ring->owner); | |
280 | ||
281 | if (ret) | |
282 | goto error_free_ring_buffer_event_chrdev; | |
283 | ||
284 | return ret; | |
285 | error_free_ring_buffer_event_chrdev: | |
286 | __iio_free_ring_buffer_event_chrdev(ring); | |
287 | error_remove_device: | |
288 | device_del(&ring->dev); | |
7026ea4b JC |
289 | error_ret: |
290 | return ret; | |
291 | } | |
292 | EXPORT_SYMBOL(iio_ring_buffer_register); | |
293 | ||
294 | void iio_ring_buffer_unregister(struct iio_ring_buffer *ring) | |
295 | { | |
296 | __iio_free_ring_buffer_access_chrdev(ring); | |
297 | __iio_free_ring_buffer_event_chrdev(ring); | |
298 | device_del(&ring->dev); | |
7026ea4b JC |
299 | } |
300 | EXPORT_SYMBOL(iio_ring_buffer_unregister); | |
301 | ||
302 | ssize_t iio_read_ring_length(struct device *dev, | |
303 | struct device_attribute *attr, | |
304 | char *buf) | |
305 | { | |
306 | int len = 0; | |
307 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
308 | ||
309 | if (ring->access.get_length) | |
310 | len = sprintf(buf, "%d\n", | |
311 | ring->access.get_length(ring)); | |
312 | ||
313 | return len; | |
314 | } | |
315 | EXPORT_SYMBOL(iio_read_ring_length); | |
316 | ||
317 | ssize_t iio_write_ring_length(struct device *dev, | |
318 | struct device_attribute *attr, | |
319 | const char *buf, | |
320 | size_t len) | |
321 | { | |
322 | int ret; | |
323 | ulong val; | |
324 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
325 | ret = strict_strtoul(buf, 10, &val); | |
326 | if (ret) | |
327 | return ret; | |
328 | ||
329 | if (ring->access.get_length) | |
330 | if (val == ring->access.get_length(ring)) | |
331 | return len; | |
332 | ||
333 | if (ring->access.set_length) { | |
334 | ring->access.set_length(ring, val); | |
335 | if (ring->access.mark_param_change) | |
336 | ring->access.mark_param_change(ring); | |
337 | } | |
338 | ||
339 | return len; | |
340 | } | |
341 | EXPORT_SYMBOL(iio_write_ring_length); | |
342 | ||
343 | ssize_t iio_read_ring_bps(struct device *dev, | |
344 | struct device_attribute *attr, | |
345 | char *buf) | |
346 | { | |
347 | int len = 0; | |
348 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
349 | ||
350 | if (ring->access.get_bpd) | |
351 | len = sprintf(buf, "%d\n", | |
352 | ring->access.get_bpd(ring)); | |
353 | ||
354 | return len; | |
355 | } | |
356 | EXPORT_SYMBOL(iio_read_ring_bps); | |
357 | ||
358 | ssize_t iio_store_ring_enable(struct device *dev, | |
359 | struct device_attribute *attr, | |
360 | const char *buf, | |
361 | size_t len) | |
362 | { | |
363 | int ret; | |
364 | bool requested_state, current_state; | |
365 | int previous_mode; | |
366 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
367 | struct iio_dev *dev_info = ring->indio_dev; | |
368 | ||
369 | mutex_lock(&dev_info->mlock); | |
370 | previous_mode = dev_info->currentmode; | |
371 | requested_state = !(buf[0] == '0'); | |
372 | current_state = !!(previous_mode & INDIO_ALL_RING_MODES); | |
373 | if (current_state == requested_state) { | |
374 | printk(KERN_INFO "iio-ring, current state requested again\n"); | |
375 | goto done; | |
376 | } | |
377 | if (requested_state) { | |
378 | if (ring->preenable) { | |
379 | ret = ring->preenable(dev_info); | |
380 | if (ret) { | |
381 | printk(KERN_ERR | |
382 | "Buffer not started:" | |
383 | "ring preenable failed\n"); | |
384 | goto error_ret; | |
385 | } | |
386 | } | |
387 | if (ring->access.request_update) { | |
388 | ret = ring->access.request_update(ring); | |
389 | if (ret) { | |
390 | printk(KERN_INFO | |
391 | "Buffer not started:" | |
392 | "ring parameter update failed\n"); | |
393 | goto error_ret; | |
394 | } | |
395 | } | |
396 | if (ring->access.mark_in_use) | |
397 | ring->access.mark_in_use(ring); | |
398 | /* Definitely possible for devices to support both of these.*/ | |
399 | if (dev_info->modes & INDIO_RING_TRIGGERED) { | |
400 | if (!dev_info->trig) { | |
401 | printk(KERN_INFO | |
402 | "Buffer not started: no trigger\n"); | |
403 | ret = -EINVAL; | |
404 | if (ring->access.unmark_in_use) | |
405 | ring->access.unmark_in_use(ring); | |
406 | goto error_ret; | |
407 | } | |
408 | dev_info->currentmode = INDIO_RING_TRIGGERED; | |
409 | } else if (dev_info->modes & INDIO_RING_HARDWARE_BUFFER) | |
410 | dev_info->currentmode = INDIO_RING_HARDWARE_BUFFER; | |
411 | else { /* should never be reached */ | |
412 | ret = -EINVAL; | |
413 | goto error_ret; | |
414 | } | |
415 | ||
416 | if (ring->postenable) { | |
417 | ||
418 | ret = ring->postenable(dev_info); | |
419 | if (ret) { | |
420 | printk(KERN_INFO | |
421 | "Buffer not started:" | |
422 | "postenable failed\n"); | |
423 | if (ring->access.unmark_in_use) | |
424 | ring->access.unmark_in_use(ring); | |
425 | dev_info->currentmode = previous_mode; | |
426 | if (ring->postdisable) | |
427 | ring->postdisable(dev_info); | |
428 | goto error_ret; | |
429 | } | |
430 | } | |
431 | } else { | |
432 | if (ring->predisable) { | |
433 | ret = ring->predisable(dev_info); | |
434 | if (ret) | |
435 | goto error_ret; | |
436 | } | |
437 | if (ring->access.unmark_in_use) | |
438 | ring->access.unmark_in_use(ring); | |
439 | dev_info->currentmode = INDIO_DIRECT_MODE; | |
440 | if (ring->postdisable) { | |
441 | ret = ring->postdisable(dev_info); | |
442 | if (ret) | |
443 | goto error_ret; | |
444 | } | |
445 | } | |
446 | done: | |
447 | mutex_unlock(&dev_info->mlock); | |
448 | return len; | |
449 | ||
450 | error_ret: | |
451 | mutex_unlock(&dev_info->mlock); | |
452 | return ret; | |
453 | } | |
454 | EXPORT_SYMBOL(iio_store_ring_enable); | |
455 | ssize_t iio_show_ring_enable(struct device *dev, | |
456 | struct device_attribute *attr, | |
457 | char *buf) | |
458 | { | |
459 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
460 | return sprintf(buf, "%d\n", !!(ring->indio_dev->currentmode | |
461 | & INDIO_ALL_RING_MODES)); | |
462 | } | |
463 | EXPORT_SYMBOL(iio_show_ring_enable); | |
464 | ||
465 | ssize_t iio_scan_el_show(struct device *dev, | |
466 | struct device_attribute *attr, | |
467 | char *buf) | |
468 | { | |
469 | int ret; | |
470 | struct iio_dev *indio_dev = dev_get_drvdata(dev); | |
471 | struct iio_scan_el *this_el = to_iio_scan_el(attr); | |
472 | ||
473 | ret = iio_scan_mask_query(indio_dev, this_el->number); | |
474 | if (ret < 0) | |
475 | return ret; | |
476 | return sprintf(buf, "%d\n", ret); | |
477 | } | |
478 | EXPORT_SYMBOL(iio_scan_el_show); | |
479 | ||
480 | ssize_t iio_scan_el_store(struct device *dev, | |
481 | struct device_attribute *attr, | |
482 | const char *buf, | |
483 | size_t len) | |
484 | { | |
485 | int ret = 0; | |
486 | bool state; | |
487 | struct iio_dev *indio_dev = dev_get_drvdata(dev); | |
488 | struct iio_scan_el *this_el = to_iio_scan_el(attr); | |
489 | ||
490 | state = !(buf[0] == '0'); | |
491 | mutex_lock(&indio_dev->mlock); | |
492 | if (indio_dev->currentmode == INDIO_RING_TRIGGERED) { | |
493 | ret = -EBUSY; | |
494 | goto error_ret; | |
495 | } | |
496 | ret = iio_scan_mask_query(indio_dev, this_el->number); | |
497 | if (ret < 0) | |
498 | goto error_ret; | |
499 | if (!state && ret) { | |
500 | ret = iio_scan_mask_clear(indio_dev, this_el->number); | |
501 | if (ret) | |
502 | goto error_ret; | |
503 | indio_dev->scan_count--; | |
504 | } else if (state && !ret) { | |
505 | ret = iio_scan_mask_set(indio_dev, this_el->number); | |
506 | if (ret) | |
507 | goto error_ret; | |
508 | indio_dev->scan_count++; | |
509 | } | |
510 | if (this_el->set_state) | |
511 | ret = this_el->set_state(this_el, indio_dev, state); | |
512 | error_ret: | |
513 | mutex_unlock(&indio_dev->mlock); | |
514 | ||
515 | return ret ? ret : len; | |
516 | ||
517 | } | |
518 | EXPORT_SYMBOL(iio_scan_el_store); | |
519 | ||
520 | ssize_t iio_scan_el_ts_show(struct device *dev, | |
521 | struct device_attribute *attr, | |
522 | char *buf) | |
523 | { | |
524 | struct iio_dev *indio_dev = dev_get_drvdata(dev); | |
525 | return sprintf(buf, "%d\n", indio_dev->scan_timestamp); | |
526 | } | |
527 | EXPORT_SYMBOL(iio_scan_el_ts_show); | |
528 | ||
529 | ssize_t iio_scan_el_ts_store(struct device *dev, | |
530 | struct device_attribute *attr, | |
531 | const char *buf, | |
532 | size_t len) | |
533 | { | |
534 | int ret = 0; | |
535 | struct iio_dev *indio_dev = dev_get_drvdata(dev); | |
536 | bool state; | |
537 | state = !(buf[0] == '0'); | |
538 | mutex_lock(&indio_dev->mlock); | |
539 | if (indio_dev->currentmode == INDIO_RING_TRIGGERED) { | |
540 | ret = -EBUSY; | |
541 | goto error_ret; | |
542 | } | |
543 | indio_dev->scan_timestamp = state; | |
544 | error_ret: | |
545 | mutex_unlock(&indio_dev->mlock); | |
546 | ||
547 | return ret ? ret : len; | |
548 | } | |
549 | EXPORT_SYMBOL(iio_scan_el_ts_store); | |
550 |