Commit | Line | Data |
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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> | |
7026ea4b JC |
18 | #include <linux/fs.h> |
19 | #include <linux/poll.h> | |
7026ea4b | 20 | #include <linux/cdev.h> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
7026ea4b JC |
22 | |
23 | #include "iio.h" | |
24 | #include "ring_generic.h" | |
25 | ||
7026ea4b JC |
26 | int iio_push_ring_event(struct iio_ring_buffer *ring_buf, |
27 | int event_code, | |
28 | s64 timestamp) | |
29 | { | |
30 | return __iio_push_event(&ring_buf->ev_int, | |
31 | event_code, | |
32 | timestamp, | |
33 | &ring_buf->shared_ev_pointer); | |
34 | } | |
35 | EXPORT_SYMBOL(iio_push_ring_event); | |
36 | ||
37 | int iio_push_or_escallate_ring_event(struct iio_ring_buffer *ring_buf, | |
38 | int event_code, | |
39 | s64 timestamp) | |
40 | { | |
41 | if (ring_buf->shared_ev_pointer.ev_p) | |
42 | __iio_change_event(ring_buf->shared_ev_pointer.ev_p, | |
43 | event_code, | |
44 | timestamp); | |
45 | else | |
46 | return iio_push_ring_event(ring_buf, | |
47 | event_code, | |
48 | timestamp); | |
49 | return 0; | |
50 | } | |
51 | EXPORT_SYMBOL(iio_push_or_escallate_ring_event); | |
52 | ||
53 | /** | |
c3e5d410 | 54 | * iio_ring_open() - chrdev file open for ring buffer access |
7026ea4b JC |
55 | * |
56 | * This function relies on all ring buffer implementations having an | |
57 | * iio_ring_buffer as their first element. | |
58 | **/ | |
0deebb4f | 59 | static int iio_ring_open(struct inode *inode, struct file *filp) |
7026ea4b JC |
60 | { |
61 | struct iio_handler *hand | |
62 | = container_of(inode->i_cdev, struct iio_handler, chrdev); | |
63 | struct iio_ring_buffer *rb = hand->private; | |
64 | ||
65 | filp->private_data = hand->private; | |
66 | if (rb->access.mark_in_use) | |
67 | rb->access.mark_in_use(rb); | |
68 | ||
69 | return 0; | |
70 | } | |
71 | ||
72 | /** | |
c3e5d410 | 73 | * iio_ring_release() - chrdev file close ring buffer access |
7026ea4b JC |
74 | * |
75 | * This function relies on all ring buffer implementations having an | |
76 | * iio_ring_buffer as their first element. | |
77 | **/ | |
0deebb4f | 78 | static int iio_ring_release(struct inode *inode, struct file *filp) |
7026ea4b JC |
79 | { |
80 | struct cdev *cd = inode->i_cdev; | |
81 | struct iio_handler *hand = iio_cdev_to_handler(cd); | |
82 | struct iio_ring_buffer *rb = hand->private; | |
83 | ||
84 | clear_bit(IIO_BUSY_BIT_POS, &rb->access_handler.flags); | |
85 | if (rb->access.unmark_in_use) | |
86 | rb->access.unmark_in_use(rb); | |
87 | ||
88 | return 0; | |
89 | } | |
90 | ||
91 | /** | |
c3e5d410 | 92 | * iio_ring_rip_outer() - chrdev read for ring buffer access |
7026ea4b JC |
93 | * |
94 | * This function relies on all ring buffer implementations having an | |
95 | * iio_ring _bufer as their first element. | |
96 | **/ | |
0deebb4f GKH |
97 | static ssize_t iio_ring_rip_outer(struct file *filp, char __user *buf, |
98 | size_t count, loff_t *f_ps) | |
7026ea4b JC |
99 | { |
100 | struct iio_ring_buffer *rb = filp->private_data; | |
101 | int ret, dead_offset, copied; | |
102 | u8 *data; | |
103 | /* rip lots must exist. */ | |
104 | if (!rb->access.rip_lots) | |
105 | return -EINVAL; | |
106 | copied = rb->access.rip_lots(rb, count, &data, &dead_offset); | |
107 | ||
108 | if (copied < 0) { | |
109 | ret = copied; | |
110 | goto error_ret; | |
111 | } | |
112 | if (copy_to_user(buf, data + dead_offset, copied)) { | |
113 | ret = -EFAULT; | |
114 | goto error_free_data_cpy; | |
115 | } | |
116 | /* In clever ring buffer designs this may not need to be freed. | |
117 | * When such a design exists I'll add this to ring access funcs. | |
118 | */ | |
119 | kfree(data); | |
120 | ||
121 | return copied; | |
122 | ||
123 | error_free_data_cpy: | |
124 | kfree(data); | |
125 | error_ret: | |
126 | return ret; | |
127 | } | |
128 | ||
129 | static const struct file_operations iio_ring_fileops = { | |
130 | .read = iio_ring_rip_outer, | |
131 | .release = iio_ring_release, | |
132 | .open = iio_ring_open, | |
133 | .owner = THIS_MODULE, | |
134 | }; | |
135 | ||
136 | /** | |
c3e5d410 | 137 | * __iio_request_ring_buffer_event_chrdev() - allocate ring event chrdev |
7026ea4b | 138 | * @buf: ring buffer whose event chrdev we are allocating |
c3e5d410 | 139 | * @id: id of this ring buffer (typically 0) |
7026ea4b JC |
140 | * @owner: the module who owns the ring buffer (for ref counting) |
141 | * @dev: device with which the chrdev is associated | |
142 | **/ | |
143 | static inline int | |
144 | __iio_request_ring_buffer_event_chrdev(struct iio_ring_buffer *buf, | |
145 | int id, | |
146 | struct module *owner, | |
147 | struct device *dev) | |
148 | { | |
149 | int ret; | |
758d988c | 150 | |
ba5c6fba JC |
151 | snprintf(buf->ev_int._name, sizeof(buf->ev_int._name), |
152 | "%s:event%d", | |
153 | dev_name(&buf->dev), | |
3d550fba | 154 | id); |
7026ea4b JC |
155 | ret = iio_setup_ev_int(&(buf->ev_int), |
156 | buf->ev_int._name, | |
157 | owner, | |
158 | dev); | |
159 | if (ret) | |
758d988c | 160 | goto error_ret; |
7026ea4b JC |
161 | return 0; |
162 | ||
7026ea4b JC |
163 | error_ret: |
164 | return ret; | |
165 | } | |
166 | ||
167 | static inline void | |
168 | __iio_free_ring_buffer_event_chrdev(struct iio_ring_buffer *buf) | |
169 | { | |
170 | iio_free_ev_int(&(buf->ev_int)); | |
7026ea4b JC |
171 | } |
172 | ||
173 | static void iio_ring_access_release(struct device *dev) | |
174 | { | |
175 | struct iio_ring_buffer *buf | |
176 | = access_dev_to_iio_ring_buffer(dev); | |
177 | cdev_del(&buf->access_handler.chrdev); | |
178 | iio_device_free_chrdev_minor(MINOR(dev->devt)); | |
179 | } | |
180 | ||
181 | static struct device_type iio_ring_access_type = { | |
182 | .release = iio_ring_access_release, | |
183 | }; | |
184 | ||
185 | static inline int | |
186 | __iio_request_ring_buffer_access_chrdev(struct iio_ring_buffer *buf, | |
187 | int id, | |
188 | struct module *owner) | |
189 | { | |
190 | int ret, minor; | |
191 | ||
192 | buf->access_handler.flags = 0; | |
193 | ||
194 | buf->access_dev.parent = &buf->dev; | |
5aaaeba8 | 195 | buf->access_dev.bus = &iio_bus_type; |
7026ea4b JC |
196 | buf->access_dev.type = &iio_ring_access_type; |
197 | device_initialize(&buf->access_dev); | |
198 | ||
199 | minor = iio_device_get_chrdev_minor(); | |
200 | if (minor < 0) { | |
201 | ret = minor; | |
202 | goto error_device_put; | |
203 | } | |
204 | buf->access_dev.devt = MKDEV(MAJOR(iio_devt), minor); | |
205 | ||
758d988c JC |
206 | |
207 | buf->access_id = id; | |
208 | ||
ba5c6fba JC |
209 | dev_set_name(&buf->access_dev, "%s:access%d", |
210 | dev_name(&buf->dev), | |
211 | buf->access_id); | |
7026ea4b JC |
212 | ret = device_add(&buf->access_dev); |
213 | if (ret < 0) { | |
214 | printk(KERN_ERR "failed to add the ring access dev\n"); | |
758d988c | 215 | goto error_device_put; |
7026ea4b JC |
216 | } |
217 | ||
218 | cdev_init(&buf->access_handler.chrdev, &iio_ring_fileops); | |
219 | buf->access_handler.chrdev.owner = owner; | |
220 | ||
221 | ret = cdev_add(&buf->access_handler.chrdev, buf->access_dev.devt, 1); | |
222 | if (ret) { | |
223 | printk(KERN_ERR "failed to allocate ring access chrdev\n"); | |
224 | goto error_device_unregister; | |
225 | } | |
226 | return 0; | |
758d988c | 227 | |
7026ea4b JC |
228 | error_device_unregister: |
229 | device_unregister(&buf->access_dev); | |
7026ea4b JC |
230 | error_device_put: |
231 | put_device(&buf->access_dev); | |
232 | ||
233 | return ret; | |
234 | } | |
235 | ||
236 | static void __iio_free_ring_buffer_access_chrdev(struct iio_ring_buffer *buf) | |
237 | { | |
7026ea4b JC |
238 | device_unregister(&buf->access_dev); |
239 | } | |
240 | ||
241 | void iio_ring_buffer_init(struct iio_ring_buffer *ring, | |
242 | struct iio_dev *dev_info) | |
243 | { | |
244 | if (ring->access.mark_param_change) | |
245 | ring->access.mark_param_change(ring); | |
246 | ring->indio_dev = dev_info; | |
247 | ring->ev_int.private = ring; | |
248 | ring->access_handler.private = ring; | |
0deebb4f | 249 | ring->shared_ev_pointer.ev_p = NULL; |
6f2dfb31 | 250 | spin_lock_init(&ring->shared_ev_pointer.lock); |
7026ea4b JC |
251 | } |
252 | EXPORT_SYMBOL(iio_ring_buffer_init); | |
253 | ||
758d988c | 254 | int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id) |
7026ea4b JC |
255 | { |
256 | int ret; | |
758d988c JC |
257 | |
258 | ring->id = id; | |
7026ea4b | 259 | |
ba5c6fba JC |
260 | dev_set_name(&ring->dev, "%s:buffer%d", |
261 | dev_name(ring->dev.parent), | |
262 | ring->id); | |
7026ea4b JC |
263 | ret = device_add(&ring->dev); |
264 | if (ret) | |
758d988c | 265 | goto error_ret; |
7026ea4b JC |
266 | |
267 | ret = __iio_request_ring_buffer_event_chrdev(ring, | |
268 | 0, | |
269 | ring->owner, | |
270 | &ring->dev); | |
271 | if (ret) | |
272 | goto error_remove_device; | |
273 | ||
274 | ret = __iio_request_ring_buffer_access_chrdev(ring, | |
275 | 0, | |
276 | ring->owner); | |
277 | ||
278 | if (ret) | |
279 | goto error_free_ring_buffer_event_chrdev; | |
280 | ||
bf32963c MS |
281 | if (ring->scan_el_attrs) { |
282 | ret = sysfs_create_group(&ring->dev.kobj, | |
283 | ring->scan_el_attrs); | |
284 | if (ret) { | |
285 | dev_err(&ring->dev, | |
286 | "Failed to add sysfs scan elements\n"); | |
287 | goto error_free_ring_buffer_event_chrdev; | |
288 | } | |
289 | } | |
290 | ||
7026ea4b JC |
291 | return ret; |
292 | error_free_ring_buffer_event_chrdev: | |
293 | __iio_free_ring_buffer_event_chrdev(ring); | |
294 | error_remove_device: | |
295 | device_del(&ring->dev); | |
7026ea4b JC |
296 | error_ret: |
297 | return ret; | |
298 | } | |
299 | EXPORT_SYMBOL(iio_ring_buffer_register); | |
300 | ||
301 | void iio_ring_buffer_unregister(struct iio_ring_buffer *ring) | |
302 | { | |
bf32963c MS |
303 | if (ring->scan_el_attrs) |
304 | sysfs_remove_group(&ring->dev.kobj, | |
305 | ring->scan_el_attrs); | |
306 | ||
7026ea4b JC |
307 | __iio_free_ring_buffer_access_chrdev(ring); |
308 | __iio_free_ring_buffer_event_chrdev(ring); | |
309 | device_del(&ring->dev); | |
7026ea4b JC |
310 | } |
311 | EXPORT_SYMBOL(iio_ring_buffer_unregister); | |
312 | ||
313 | ssize_t iio_read_ring_length(struct device *dev, | |
314 | struct device_attribute *attr, | |
315 | char *buf) | |
316 | { | |
317 | int len = 0; | |
318 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
319 | ||
320 | if (ring->access.get_length) | |
321 | len = sprintf(buf, "%d\n", | |
322 | ring->access.get_length(ring)); | |
323 | ||
324 | return len; | |
325 | } | |
326 | EXPORT_SYMBOL(iio_read_ring_length); | |
327 | ||
0abd2428 | 328 | ssize_t iio_write_ring_length(struct device *dev, |
7026ea4b JC |
329 | struct device_attribute *attr, |
330 | const char *buf, | |
331 | size_t len) | |
332 | { | |
333 | int ret; | |
334 | ulong val; | |
335 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
336 | ret = strict_strtoul(buf, 10, &val); | |
337 | if (ret) | |
338 | return ret; | |
339 | ||
340 | if (ring->access.get_length) | |
341 | if (val == ring->access.get_length(ring)) | |
342 | return len; | |
343 | ||
344 | if (ring->access.set_length) { | |
345 | ring->access.set_length(ring, val); | |
346 | if (ring->access.mark_param_change) | |
347 | ring->access.mark_param_change(ring); | |
348 | } | |
349 | ||
350 | return len; | |
351 | } | |
352 | EXPORT_SYMBOL(iio_write_ring_length); | |
353 | ||
ffcab07a | 354 | ssize_t iio_read_ring_bytes_per_datum(struct device *dev, |
7026ea4b JC |
355 | struct device_attribute *attr, |
356 | char *buf) | |
357 | { | |
358 | int len = 0; | |
359 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
360 | ||
ffcab07a | 361 | if (ring->access.get_bytes_per_datum) |
7026ea4b | 362 | len = sprintf(buf, "%d\n", |
ffcab07a | 363 | ring->access.get_bytes_per_datum(ring)); |
7026ea4b JC |
364 | |
365 | return len; | |
366 | } | |
ffcab07a | 367 | EXPORT_SYMBOL(iio_read_ring_bytes_per_datum); |
7026ea4b JC |
368 | |
369 | ssize_t iio_store_ring_enable(struct device *dev, | |
370 | struct device_attribute *attr, | |
371 | const char *buf, | |
372 | size_t len) | |
373 | { | |
374 | int ret; | |
375 | bool requested_state, current_state; | |
376 | int previous_mode; | |
377 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
378 | struct iio_dev *dev_info = ring->indio_dev; | |
379 | ||
380 | mutex_lock(&dev_info->mlock); | |
381 | previous_mode = dev_info->currentmode; | |
382 | requested_state = !(buf[0] == '0'); | |
383 | current_state = !!(previous_mode & INDIO_ALL_RING_MODES); | |
384 | if (current_state == requested_state) { | |
385 | printk(KERN_INFO "iio-ring, current state requested again\n"); | |
386 | goto done; | |
387 | } | |
388 | if (requested_state) { | |
389 | if (ring->preenable) { | |
390 | ret = ring->preenable(dev_info); | |
391 | if (ret) { | |
392 | printk(KERN_ERR | |
393 | "Buffer not started:" | |
394 | "ring preenable failed\n"); | |
395 | goto error_ret; | |
396 | } | |
397 | } | |
398 | if (ring->access.request_update) { | |
399 | ret = ring->access.request_update(ring); | |
400 | if (ret) { | |
401 | printk(KERN_INFO | |
402 | "Buffer not started:" | |
403 | "ring parameter update failed\n"); | |
404 | goto error_ret; | |
405 | } | |
406 | } | |
407 | if (ring->access.mark_in_use) | |
408 | ring->access.mark_in_use(ring); | |
409 | /* Definitely possible for devices to support both of these.*/ | |
410 | if (dev_info->modes & INDIO_RING_TRIGGERED) { | |
411 | if (!dev_info->trig) { | |
412 | printk(KERN_INFO | |
413 | "Buffer not started: no trigger\n"); | |
414 | ret = -EINVAL; | |
415 | if (ring->access.unmark_in_use) | |
416 | ring->access.unmark_in_use(ring); | |
417 | goto error_ret; | |
418 | } | |
419 | dev_info->currentmode = INDIO_RING_TRIGGERED; | |
420 | } else if (dev_info->modes & INDIO_RING_HARDWARE_BUFFER) | |
421 | dev_info->currentmode = INDIO_RING_HARDWARE_BUFFER; | |
422 | else { /* should never be reached */ | |
423 | ret = -EINVAL; | |
424 | goto error_ret; | |
425 | } | |
426 | ||
427 | if (ring->postenable) { | |
428 | ||
429 | ret = ring->postenable(dev_info); | |
430 | if (ret) { | |
431 | printk(KERN_INFO | |
432 | "Buffer not started:" | |
433 | "postenable failed\n"); | |
434 | if (ring->access.unmark_in_use) | |
435 | ring->access.unmark_in_use(ring); | |
436 | dev_info->currentmode = previous_mode; | |
437 | if (ring->postdisable) | |
438 | ring->postdisable(dev_info); | |
439 | goto error_ret; | |
440 | } | |
441 | } | |
442 | } else { | |
443 | if (ring->predisable) { | |
444 | ret = ring->predisable(dev_info); | |
445 | if (ret) | |
446 | goto error_ret; | |
447 | } | |
448 | if (ring->access.unmark_in_use) | |
449 | ring->access.unmark_in_use(ring); | |
450 | dev_info->currentmode = INDIO_DIRECT_MODE; | |
451 | if (ring->postdisable) { | |
452 | ret = ring->postdisable(dev_info); | |
453 | if (ret) | |
454 | goto error_ret; | |
455 | } | |
456 | } | |
457 | done: | |
458 | mutex_unlock(&dev_info->mlock); | |
459 | return len; | |
460 | ||
461 | error_ret: | |
462 | mutex_unlock(&dev_info->mlock); | |
463 | return ret; | |
464 | } | |
465 | EXPORT_SYMBOL(iio_store_ring_enable); | |
466 | ssize_t iio_show_ring_enable(struct device *dev, | |
467 | struct device_attribute *attr, | |
468 | char *buf) | |
469 | { | |
470 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
471 | return sprintf(buf, "%d\n", !!(ring->indio_dev->currentmode | |
472 | & INDIO_ALL_RING_MODES)); | |
473 | } | |
474 | EXPORT_SYMBOL(iio_show_ring_enable); | |
475 | ||
476 | ssize_t iio_scan_el_show(struct device *dev, | |
477 | struct device_attribute *attr, | |
478 | char *buf) | |
479 | { | |
480 | int ret; | |
bf32963c | 481 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); |
7026ea4b JC |
482 | struct iio_scan_el *this_el = to_iio_scan_el(attr); |
483 | ||
bf32963c | 484 | ret = iio_scan_mask_query(ring, this_el->number); |
7026ea4b JC |
485 | if (ret < 0) |
486 | return ret; | |
487 | return sprintf(buf, "%d\n", ret); | |
488 | } | |
489 | EXPORT_SYMBOL(iio_scan_el_show); | |
490 | ||
491 | ssize_t iio_scan_el_store(struct device *dev, | |
492 | struct device_attribute *attr, | |
493 | const char *buf, | |
494 | size_t len) | |
495 | { | |
496 | int ret = 0; | |
497 | bool state; | |
bf32963c MS |
498 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); |
499 | struct iio_dev *indio_dev = ring->indio_dev; | |
7026ea4b JC |
500 | struct iio_scan_el *this_el = to_iio_scan_el(attr); |
501 | ||
502 | state = !(buf[0] == '0'); | |
503 | mutex_lock(&indio_dev->mlock); | |
504 | if (indio_dev->currentmode == INDIO_RING_TRIGGERED) { | |
505 | ret = -EBUSY; | |
506 | goto error_ret; | |
507 | } | |
bf32963c | 508 | ret = iio_scan_mask_query(ring, this_el->number); |
7026ea4b JC |
509 | if (ret < 0) |
510 | goto error_ret; | |
511 | if (!state && ret) { | |
bf32963c | 512 | ret = iio_scan_mask_clear(ring, this_el->number); |
7026ea4b JC |
513 | if (ret) |
514 | goto error_ret; | |
7026ea4b | 515 | } else if (state && !ret) { |
bf32963c | 516 | ret = iio_scan_mask_set(ring, this_el->number); |
7026ea4b JC |
517 | if (ret) |
518 | goto error_ret; | |
7026ea4b JC |
519 | } |
520 | if (this_el->set_state) | |
521 | ret = this_el->set_state(this_el, indio_dev, state); | |
522 | error_ret: | |
523 | mutex_unlock(&indio_dev->mlock); | |
524 | ||
525 | return ret ? ret : len; | |
526 | ||
527 | } | |
528 | EXPORT_SYMBOL(iio_scan_el_store); | |
529 | ||
530 | ssize_t iio_scan_el_ts_show(struct device *dev, | |
531 | struct device_attribute *attr, | |
532 | char *buf) | |
533 | { | |
bf32963c MS |
534 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); |
535 | return sprintf(buf, "%d\n", ring->scan_timestamp); | |
7026ea4b JC |
536 | } |
537 | EXPORT_SYMBOL(iio_scan_el_ts_show); | |
538 | ||
539 | ssize_t iio_scan_el_ts_store(struct device *dev, | |
540 | struct device_attribute *attr, | |
541 | const char *buf, | |
542 | size_t len) | |
543 | { | |
544 | int ret = 0; | |
bf32963c MS |
545 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); |
546 | struct iio_dev *indio_dev = ring->indio_dev; | |
7026ea4b JC |
547 | bool state; |
548 | state = !(buf[0] == '0'); | |
549 | mutex_lock(&indio_dev->mlock); | |
550 | if (indio_dev->currentmode == INDIO_RING_TRIGGERED) { | |
551 | ret = -EBUSY; | |
552 | goto error_ret; | |
553 | } | |
bf32963c | 554 | ring->scan_timestamp = state; |
7026ea4b JC |
555 | error_ret: |
556 | mutex_unlock(&indio_dev->mlock); | |
557 | ||
558 | return ret ? ret : len; | |
559 | } | |
560 | EXPORT_SYMBOL(iio_scan_el_ts_store); | |
561 |