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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 | 18 | #include <linux/fs.h> |
7026ea4b | 19 | #include <linux/cdev.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
7026ea4b JC |
21 | |
22 | #include "iio.h" | |
23 | #include "ring_generic.h" | |
24 | ||
7026ea4b JC |
25 | int iio_push_ring_event(struct iio_ring_buffer *ring_buf, |
26 | int event_code, | |
27 | s64 timestamp) | |
28 | { | |
29 | return __iio_push_event(&ring_buf->ev_int, | |
30 | event_code, | |
31 | timestamp, | |
32 | &ring_buf->shared_ev_pointer); | |
33 | } | |
34 | EXPORT_SYMBOL(iio_push_ring_event); | |
35 | ||
36 | int iio_push_or_escallate_ring_event(struct iio_ring_buffer *ring_buf, | |
37 | int event_code, | |
38 | s64 timestamp) | |
39 | { | |
40 | if (ring_buf->shared_ev_pointer.ev_p) | |
41 | __iio_change_event(ring_buf->shared_ev_pointer.ev_p, | |
42 | event_code, | |
43 | timestamp); | |
44 | else | |
45 | return iio_push_ring_event(ring_buf, | |
46 | event_code, | |
47 | timestamp); | |
48 | return 0; | |
49 | } | |
50 | EXPORT_SYMBOL(iio_push_or_escallate_ring_event); | |
51 | ||
52 | /** | |
c3e5d410 | 53 | * iio_ring_open() - chrdev file open for ring buffer access |
7026ea4b JC |
54 | * |
55 | * This function relies on all ring buffer implementations having an | |
56 | * iio_ring_buffer as their first element. | |
57 | **/ | |
0deebb4f | 58 | static int iio_ring_open(struct inode *inode, struct file *filp) |
7026ea4b JC |
59 | { |
60 | struct iio_handler *hand | |
61 | = container_of(inode->i_cdev, struct iio_handler, chrdev); | |
62 | struct iio_ring_buffer *rb = hand->private; | |
63 | ||
64 | filp->private_data = hand->private; | |
65 | if (rb->access.mark_in_use) | |
66 | rb->access.mark_in_use(rb); | |
67 | ||
68 | return 0; | |
69 | } | |
70 | ||
71 | /** | |
c3e5d410 | 72 | * iio_ring_release() - chrdev file close ring buffer access |
7026ea4b JC |
73 | * |
74 | * This function relies on all ring buffer implementations having an | |
75 | * iio_ring_buffer as their first element. | |
76 | **/ | |
0deebb4f | 77 | static int iio_ring_release(struct inode *inode, struct file *filp) |
7026ea4b JC |
78 | { |
79 | struct cdev *cd = inode->i_cdev; | |
80 | struct iio_handler *hand = iio_cdev_to_handler(cd); | |
81 | struct iio_ring_buffer *rb = hand->private; | |
82 | ||
83 | clear_bit(IIO_BUSY_BIT_POS, &rb->access_handler.flags); | |
84 | if (rb->access.unmark_in_use) | |
85 | rb->access.unmark_in_use(rb); | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | /** | |
b4281733 | 91 | * iio_ring_read_first_n_outer() - chrdev read for ring buffer access |
7026ea4b JC |
92 | * |
93 | * This function relies on all ring buffer implementations having an | |
94 | * iio_ring _bufer as their first element. | |
95 | **/ | |
b4281733 JC |
96 | static ssize_t iio_ring_read_first_n_outer(struct file *filp, char __user *buf, |
97 | size_t n, loff_t *f_ps) | |
7026ea4b JC |
98 | { |
99 | struct iio_ring_buffer *rb = filp->private_data; | |
d5857d65 JC |
100 | int ret, dead_offset; |
101 | ||
7026ea4b | 102 | /* rip lots must exist. */ |
b4281733 | 103 | if (!rb->access.read_first_n) |
7026ea4b | 104 | return -EINVAL; |
b4281733 | 105 | ret = rb->access.read_first_n(rb, n, buf, &dead_offset); |
7026ea4b | 106 | |
7026ea4b JC |
107 | return ret; |
108 | } | |
109 | ||
110 | static const struct file_operations iio_ring_fileops = { | |
b4281733 | 111 | .read = iio_ring_read_first_n_outer, |
7026ea4b JC |
112 | .release = iio_ring_release, |
113 | .open = iio_ring_open, | |
114 | .owner = THIS_MODULE, | |
6038f373 | 115 | .llseek = noop_llseek, |
7026ea4b JC |
116 | }; |
117 | ||
118 | /** | |
c3e5d410 | 119 | * __iio_request_ring_buffer_event_chrdev() - allocate ring event chrdev |
7026ea4b | 120 | * @buf: ring buffer whose event chrdev we are allocating |
c3e5d410 | 121 | * @id: id of this ring buffer (typically 0) |
7026ea4b JC |
122 | * @owner: the module who owns the ring buffer (for ref counting) |
123 | * @dev: device with which the chrdev is associated | |
124 | **/ | |
125 | static inline int | |
126 | __iio_request_ring_buffer_event_chrdev(struct iio_ring_buffer *buf, | |
127 | int id, | |
128 | struct module *owner, | |
129 | struct device *dev) | |
130 | { | |
131 | int ret; | |
758d988c | 132 | |
ba5c6fba JC |
133 | snprintf(buf->ev_int._name, sizeof(buf->ev_int._name), |
134 | "%s:event%d", | |
135 | dev_name(&buf->dev), | |
3d550fba | 136 | id); |
7026ea4b JC |
137 | ret = iio_setup_ev_int(&(buf->ev_int), |
138 | buf->ev_int._name, | |
139 | owner, | |
140 | dev); | |
141 | if (ret) | |
758d988c | 142 | goto error_ret; |
7026ea4b JC |
143 | return 0; |
144 | ||
7026ea4b JC |
145 | error_ret: |
146 | return ret; | |
147 | } | |
148 | ||
149 | static inline void | |
150 | __iio_free_ring_buffer_event_chrdev(struct iio_ring_buffer *buf) | |
151 | { | |
152 | iio_free_ev_int(&(buf->ev_int)); | |
7026ea4b JC |
153 | } |
154 | ||
155 | static void iio_ring_access_release(struct device *dev) | |
156 | { | |
157 | struct iio_ring_buffer *buf | |
158 | = access_dev_to_iio_ring_buffer(dev); | |
159 | cdev_del(&buf->access_handler.chrdev); | |
160 | iio_device_free_chrdev_minor(MINOR(dev->devt)); | |
161 | } | |
162 | ||
163 | static struct device_type iio_ring_access_type = { | |
164 | .release = iio_ring_access_release, | |
165 | }; | |
166 | ||
167 | static inline int | |
168 | __iio_request_ring_buffer_access_chrdev(struct iio_ring_buffer *buf, | |
169 | int id, | |
170 | struct module *owner) | |
171 | { | |
172 | int ret, minor; | |
173 | ||
174 | buf->access_handler.flags = 0; | |
175 | ||
176 | buf->access_dev.parent = &buf->dev; | |
5aaaeba8 | 177 | buf->access_dev.bus = &iio_bus_type; |
7026ea4b JC |
178 | buf->access_dev.type = &iio_ring_access_type; |
179 | device_initialize(&buf->access_dev); | |
180 | ||
181 | minor = iio_device_get_chrdev_minor(); | |
182 | if (minor < 0) { | |
183 | ret = minor; | |
184 | goto error_device_put; | |
185 | } | |
186 | buf->access_dev.devt = MKDEV(MAJOR(iio_devt), minor); | |
187 | ||
758d988c JC |
188 | |
189 | buf->access_id = id; | |
190 | ||
ba5c6fba JC |
191 | dev_set_name(&buf->access_dev, "%s:access%d", |
192 | dev_name(&buf->dev), | |
193 | buf->access_id); | |
7026ea4b JC |
194 | ret = device_add(&buf->access_dev); |
195 | if (ret < 0) { | |
196 | printk(KERN_ERR "failed to add the ring access dev\n"); | |
758d988c | 197 | goto error_device_put; |
7026ea4b JC |
198 | } |
199 | ||
200 | cdev_init(&buf->access_handler.chrdev, &iio_ring_fileops); | |
201 | buf->access_handler.chrdev.owner = owner; | |
202 | ||
203 | ret = cdev_add(&buf->access_handler.chrdev, buf->access_dev.devt, 1); | |
204 | if (ret) { | |
205 | printk(KERN_ERR "failed to allocate ring access chrdev\n"); | |
206 | goto error_device_unregister; | |
207 | } | |
208 | return 0; | |
758d988c | 209 | |
7026ea4b JC |
210 | error_device_unregister: |
211 | device_unregister(&buf->access_dev); | |
7026ea4b JC |
212 | error_device_put: |
213 | put_device(&buf->access_dev); | |
214 | ||
215 | return ret; | |
216 | } | |
217 | ||
218 | static void __iio_free_ring_buffer_access_chrdev(struct iio_ring_buffer *buf) | |
219 | { | |
7026ea4b JC |
220 | device_unregister(&buf->access_dev); |
221 | } | |
222 | ||
223 | void iio_ring_buffer_init(struct iio_ring_buffer *ring, | |
224 | struct iio_dev *dev_info) | |
225 | { | |
226 | if (ring->access.mark_param_change) | |
227 | ring->access.mark_param_change(ring); | |
228 | ring->indio_dev = dev_info; | |
229 | ring->ev_int.private = ring; | |
230 | ring->access_handler.private = ring; | |
0deebb4f | 231 | ring->shared_ev_pointer.ev_p = NULL; |
6f2dfb31 | 232 | spin_lock_init(&ring->shared_ev_pointer.lock); |
7026ea4b JC |
233 | } |
234 | EXPORT_SYMBOL(iio_ring_buffer_init); | |
235 | ||
758d988c | 236 | int iio_ring_buffer_register(struct iio_ring_buffer *ring, int id) |
7026ea4b JC |
237 | { |
238 | int ret; | |
758d988c JC |
239 | |
240 | ring->id = id; | |
7026ea4b | 241 | |
ba5c6fba JC |
242 | dev_set_name(&ring->dev, "%s:buffer%d", |
243 | dev_name(ring->dev.parent), | |
244 | ring->id); | |
7026ea4b JC |
245 | ret = device_add(&ring->dev); |
246 | if (ret) | |
758d988c | 247 | goto error_ret; |
7026ea4b JC |
248 | |
249 | ret = __iio_request_ring_buffer_event_chrdev(ring, | |
250 | 0, | |
251 | ring->owner, | |
252 | &ring->dev); | |
253 | if (ret) | |
254 | goto error_remove_device; | |
255 | ||
256 | ret = __iio_request_ring_buffer_access_chrdev(ring, | |
257 | 0, | |
258 | ring->owner); | |
259 | ||
260 | if (ret) | |
261 | goto error_free_ring_buffer_event_chrdev; | |
262 | ||
bf32963c MS |
263 | if (ring->scan_el_attrs) { |
264 | ret = sysfs_create_group(&ring->dev.kobj, | |
265 | ring->scan_el_attrs); | |
266 | if (ret) { | |
267 | dev_err(&ring->dev, | |
268 | "Failed to add sysfs scan elements\n"); | |
269 | goto error_free_ring_buffer_event_chrdev; | |
270 | } | |
271 | } | |
272 | ||
7026ea4b JC |
273 | return ret; |
274 | error_free_ring_buffer_event_chrdev: | |
275 | __iio_free_ring_buffer_event_chrdev(ring); | |
276 | error_remove_device: | |
277 | device_del(&ring->dev); | |
7026ea4b JC |
278 | error_ret: |
279 | return ret; | |
280 | } | |
281 | EXPORT_SYMBOL(iio_ring_buffer_register); | |
282 | ||
283 | void iio_ring_buffer_unregister(struct iio_ring_buffer *ring) | |
284 | { | |
bf32963c MS |
285 | if (ring->scan_el_attrs) |
286 | sysfs_remove_group(&ring->dev.kobj, | |
287 | ring->scan_el_attrs); | |
288 | ||
7026ea4b JC |
289 | __iio_free_ring_buffer_access_chrdev(ring); |
290 | __iio_free_ring_buffer_event_chrdev(ring); | |
291 | device_del(&ring->dev); | |
7026ea4b JC |
292 | } |
293 | EXPORT_SYMBOL(iio_ring_buffer_unregister); | |
294 | ||
295 | ssize_t iio_read_ring_length(struct device *dev, | |
296 | struct device_attribute *attr, | |
297 | char *buf) | |
298 | { | |
299 | int len = 0; | |
300 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
301 | ||
302 | if (ring->access.get_length) | |
303 | len = sprintf(buf, "%d\n", | |
304 | ring->access.get_length(ring)); | |
305 | ||
306 | return len; | |
307 | } | |
308 | EXPORT_SYMBOL(iio_read_ring_length); | |
309 | ||
0abd2428 | 310 | ssize_t iio_write_ring_length(struct device *dev, |
7026ea4b JC |
311 | struct device_attribute *attr, |
312 | const char *buf, | |
313 | size_t len) | |
314 | { | |
315 | int ret; | |
316 | ulong val; | |
317 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
318 | ret = strict_strtoul(buf, 10, &val); | |
319 | if (ret) | |
320 | return ret; | |
321 | ||
322 | if (ring->access.get_length) | |
323 | if (val == ring->access.get_length(ring)) | |
324 | return len; | |
325 | ||
326 | if (ring->access.set_length) { | |
327 | ring->access.set_length(ring, val); | |
328 | if (ring->access.mark_param_change) | |
329 | ring->access.mark_param_change(ring); | |
330 | } | |
331 | ||
332 | return len; | |
333 | } | |
334 | EXPORT_SYMBOL(iio_write_ring_length); | |
335 | ||
ffcab07a | 336 | ssize_t iio_read_ring_bytes_per_datum(struct device *dev, |
7026ea4b JC |
337 | struct device_attribute *attr, |
338 | char *buf) | |
339 | { | |
340 | int len = 0; | |
341 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
342 | ||
ffcab07a | 343 | if (ring->access.get_bytes_per_datum) |
7026ea4b | 344 | len = sprintf(buf, "%d\n", |
ffcab07a | 345 | ring->access.get_bytes_per_datum(ring)); |
7026ea4b JC |
346 | |
347 | return len; | |
348 | } | |
ffcab07a | 349 | EXPORT_SYMBOL(iio_read_ring_bytes_per_datum); |
7026ea4b JC |
350 | |
351 | ssize_t iio_store_ring_enable(struct device *dev, | |
352 | struct device_attribute *attr, | |
353 | const char *buf, | |
354 | size_t len) | |
355 | { | |
356 | int ret; | |
357 | bool requested_state, current_state; | |
358 | int previous_mode; | |
359 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
360 | struct iio_dev *dev_info = ring->indio_dev; | |
361 | ||
362 | mutex_lock(&dev_info->mlock); | |
363 | previous_mode = dev_info->currentmode; | |
364 | requested_state = !(buf[0] == '0'); | |
365 | current_state = !!(previous_mode & INDIO_ALL_RING_MODES); | |
366 | if (current_state == requested_state) { | |
367 | printk(KERN_INFO "iio-ring, current state requested again\n"); | |
368 | goto done; | |
369 | } | |
370 | if (requested_state) { | |
371 | if (ring->preenable) { | |
372 | ret = ring->preenable(dev_info); | |
373 | if (ret) { | |
374 | printk(KERN_ERR | |
375 | "Buffer not started:" | |
376 | "ring preenable failed\n"); | |
377 | goto error_ret; | |
378 | } | |
379 | } | |
380 | if (ring->access.request_update) { | |
381 | ret = ring->access.request_update(ring); | |
382 | if (ret) { | |
383 | printk(KERN_INFO | |
384 | "Buffer not started:" | |
385 | "ring parameter update failed\n"); | |
386 | goto error_ret; | |
387 | } | |
388 | } | |
389 | if (ring->access.mark_in_use) | |
390 | ring->access.mark_in_use(ring); | |
391 | /* Definitely possible for devices to support both of these.*/ | |
392 | if (dev_info->modes & INDIO_RING_TRIGGERED) { | |
393 | if (!dev_info->trig) { | |
394 | printk(KERN_INFO | |
395 | "Buffer not started: no trigger\n"); | |
396 | ret = -EINVAL; | |
397 | if (ring->access.unmark_in_use) | |
398 | ring->access.unmark_in_use(ring); | |
399 | goto error_ret; | |
400 | } | |
401 | dev_info->currentmode = INDIO_RING_TRIGGERED; | |
402 | } else if (dev_info->modes & INDIO_RING_HARDWARE_BUFFER) | |
403 | dev_info->currentmode = INDIO_RING_HARDWARE_BUFFER; | |
404 | else { /* should never be reached */ | |
405 | ret = -EINVAL; | |
406 | goto error_ret; | |
407 | } | |
408 | ||
409 | if (ring->postenable) { | |
410 | ||
411 | ret = ring->postenable(dev_info); | |
412 | if (ret) { | |
413 | printk(KERN_INFO | |
414 | "Buffer not started:" | |
415 | "postenable failed\n"); | |
416 | if (ring->access.unmark_in_use) | |
417 | ring->access.unmark_in_use(ring); | |
418 | dev_info->currentmode = previous_mode; | |
419 | if (ring->postdisable) | |
420 | ring->postdisable(dev_info); | |
421 | goto error_ret; | |
422 | } | |
423 | } | |
424 | } else { | |
425 | if (ring->predisable) { | |
426 | ret = ring->predisable(dev_info); | |
427 | if (ret) | |
428 | goto error_ret; | |
429 | } | |
430 | if (ring->access.unmark_in_use) | |
431 | ring->access.unmark_in_use(ring); | |
432 | dev_info->currentmode = INDIO_DIRECT_MODE; | |
433 | if (ring->postdisable) { | |
434 | ret = ring->postdisable(dev_info); | |
435 | if (ret) | |
436 | goto error_ret; | |
437 | } | |
438 | } | |
439 | done: | |
440 | mutex_unlock(&dev_info->mlock); | |
441 | return len; | |
442 | ||
443 | error_ret: | |
444 | mutex_unlock(&dev_info->mlock); | |
445 | return ret; | |
446 | } | |
447 | EXPORT_SYMBOL(iio_store_ring_enable); | |
448 | ssize_t iio_show_ring_enable(struct device *dev, | |
449 | struct device_attribute *attr, | |
450 | char *buf) | |
451 | { | |
452 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); | |
453 | return sprintf(buf, "%d\n", !!(ring->indio_dev->currentmode | |
454 | & INDIO_ALL_RING_MODES)); | |
455 | } | |
456 | EXPORT_SYMBOL(iio_show_ring_enable); | |
457 | ||
458 | ssize_t iio_scan_el_show(struct device *dev, | |
459 | struct device_attribute *attr, | |
460 | char *buf) | |
461 | { | |
462 | int ret; | |
bf32963c | 463 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); |
7026ea4b JC |
464 | struct iio_scan_el *this_el = to_iio_scan_el(attr); |
465 | ||
bf32963c | 466 | ret = iio_scan_mask_query(ring, this_el->number); |
7026ea4b JC |
467 | if (ret < 0) |
468 | return ret; | |
469 | return sprintf(buf, "%d\n", ret); | |
470 | } | |
471 | EXPORT_SYMBOL(iio_scan_el_show); | |
472 | ||
473 | ssize_t iio_scan_el_store(struct device *dev, | |
474 | struct device_attribute *attr, | |
475 | const char *buf, | |
476 | size_t len) | |
477 | { | |
478 | int ret = 0; | |
479 | bool state; | |
bf32963c MS |
480 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); |
481 | struct iio_dev *indio_dev = ring->indio_dev; | |
7026ea4b JC |
482 | struct iio_scan_el *this_el = to_iio_scan_el(attr); |
483 | ||
484 | state = !(buf[0] == '0'); | |
485 | mutex_lock(&indio_dev->mlock); | |
486 | if (indio_dev->currentmode == INDIO_RING_TRIGGERED) { | |
487 | ret = -EBUSY; | |
488 | goto error_ret; | |
489 | } | |
bf32963c | 490 | ret = iio_scan_mask_query(ring, this_el->number); |
7026ea4b JC |
491 | if (ret < 0) |
492 | goto error_ret; | |
493 | if (!state && ret) { | |
bf32963c | 494 | ret = iio_scan_mask_clear(ring, this_el->number); |
7026ea4b JC |
495 | if (ret) |
496 | goto error_ret; | |
7026ea4b | 497 | } else if (state && !ret) { |
bf32963c | 498 | ret = iio_scan_mask_set(ring, this_el->number); |
7026ea4b JC |
499 | if (ret) |
500 | goto error_ret; | |
7026ea4b JC |
501 | } |
502 | if (this_el->set_state) | |
503 | ret = this_el->set_state(this_el, indio_dev, state); | |
504 | error_ret: | |
505 | mutex_unlock(&indio_dev->mlock); | |
506 | ||
507 | return ret ? ret : len; | |
508 | ||
509 | } | |
510 | EXPORT_SYMBOL(iio_scan_el_store); | |
511 | ||
512 | ssize_t iio_scan_el_ts_show(struct device *dev, | |
513 | struct device_attribute *attr, | |
514 | char *buf) | |
515 | { | |
bf32963c MS |
516 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); |
517 | return sprintf(buf, "%d\n", ring->scan_timestamp); | |
7026ea4b JC |
518 | } |
519 | EXPORT_SYMBOL(iio_scan_el_ts_show); | |
520 | ||
521 | ssize_t iio_scan_el_ts_store(struct device *dev, | |
522 | struct device_attribute *attr, | |
523 | const char *buf, | |
524 | size_t len) | |
525 | { | |
526 | int ret = 0; | |
bf32963c MS |
527 | struct iio_ring_buffer *ring = dev_get_drvdata(dev); |
528 | struct iio_dev *indio_dev = ring->indio_dev; | |
7026ea4b JC |
529 | bool state; |
530 | state = !(buf[0] == '0'); | |
531 | mutex_lock(&indio_dev->mlock); | |
532 | if (indio_dev->currentmode == INDIO_RING_TRIGGERED) { | |
533 | ret = -EBUSY; | |
534 | goto error_ret; | |
535 | } | |
bf32963c | 536 | ring->scan_timestamp = state; |
7026ea4b JC |
537 | error_ret: |
538 | mutex_unlock(&indio_dev->mlock); | |
539 | ||
540 | return ret ? ret : len; | |
541 | } | |
542 | EXPORT_SYMBOL(iio_scan_el_ts_store); | |
543 |