?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
irqchip/s3c24xx: Mark init_eint as __maybe_unused
[linux/fpc-iii.git] / drivers / iio / industrialio-buffer.c
blob0f6f63b2026379ffd968a764e3309f8fb792eda5
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 buffer 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/export.h>
18 #include <linux/device.h>
19 #include <linux/fs.h>
20 #include <linux/cdev.h>
21 #include <linux/slab.h>
22 #include <linux/poll.h>
23 #include <linux/sched.h>
24
25 #include <linux/iio/iio.h>
26 #include "iio_core.h"
27 #include <linux/iio/sysfs.h>
28 #include <linux/iio/buffer.h>
29
30 static const char * const iio_endian_prefix[] = {
31 [IIO_BE] = "be",
32 [IIO_LE] = "le",
33 };
34
35 static bool iio_buffer_is_active(struct iio_buffer *buf)
36 {
37 return !list_empty(&buf->buffer_list);
38 }
39
40 static size_t iio_buffer_data_available(struct iio_buffer *buf)
41 {
42 return buf->access->data_available(buf);
43 }
44
45 static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
46 struct iio_buffer *buf, size_t required)
47 {
48 if (!indio_dev->info->hwfifo_flush_to_buffer)
49 return -ENODEV;
50
51 return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
52 }
53
54 static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
55 size_t to_wait, int to_flush)
56 {
57 size_t avail;
58 int flushed = 0;
59
60 /* wakeup if the device was unregistered */
61 if (!indio_dev->info)
62 return true;
63
64 /* drain the buffer if it was disabled */
65 if (!iio_buffer_is_active(buf)) {
66 to_wait = min_t(size_t, to_wait, 1);
67 to_flush = 0;
68 }
69
70 avail = iio_buffer_data_available(buf);
71
72 if (avail >= to_wait) {
73 /* force a flush for non-blocking reads */
74 if (!to_wait && avail < to_flush)
75 iio_buffer_flush_hwfifo(indio_dev, buf,
76 to_flush - avail);
77 return true;
78 }
79
80 if (to_flush)
81 flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
82 to_wait - avail);
83 if (flushed <= 0)
84 return false;
85
86 if (avail + flushed >= to_wait)
87 return true;
88
89 return false;
90 }
91
92 /**
93 * iio_buffer_read_first_n_outer() - chrdev read for buffer access
94 * @filp: File structure pointer for the char device
95 * @buf: Destination buffer for iio buffer read
96 * @n: First n bytes to read
97 * @f_ps: Long offset provided by the user as a seek position
98 *
99 * This function relies on all buffer implementations having an
100 * iio_buffer as their first element.
101 *
102 * Return: negative values corresponding to error codes or ret != 0
103 * for ending the reading activity
104 **/
105 ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
106 size_t n, loff_t *f_ps)
107 {
108 struct iio_dev *indio_dev = filp->private_data;
109 struct iio_buffer *rb = indio_dev->buffer;
110 size_t datum_size;
111 size_t to_wait;
112 int ret;
113
114 if (!indio_dev->info)
115 return -ENODEV;
116
117 if (!rb || !rb->access->read_first_n)
118 return -EINVAL;
119
120 datum_size = rb->bytes_per_datum;
121
122 /*
123 * If datum_size is 0 there will never be anything to read from the
124 * buffer, so signal end of file now.
125 */
126 if (!datum_size)
127 return 0;
128
129 if (filp->f_flags & O_NONBLOCK)
130 to_wait = 0;
131 else
132 to_wait = min_t(size_t, n / datum_size, rb->watermark);
133
134 do {
135 ret = wait_event_interruptible(rb->pollq,
136 iio_buffer_ready(indio_dev, rb, to_wait, n / datum_size));
137 if (ret)
138 return ret;
139
140 if (!indio_dev->info)
141 return -ENODEV;
142
143 ret = rb->access->read_first_n(rb, n, buf);
144 if (ret == 0 && (filp->f_flags & O_NONBLOCK))
145 ret = -EAGAIN;
146 } while (ret == 0);
147
148 return ret;
149 }
150
151 /**
152 * iio_buffer_poll() - poll the buffer to find out if it has data
153 * @filp: File structure pointer for device access
154 * @wait: Poll table structure pointer for which the driver adds
155 * a wait queue
156 *
157 * Return: (POLLIN | POLLRDNORM) if data is available for reading
158 * or 0 for other cases
159 */
160 unsigned int iio_buffer_poll(struct file *filp,
161 struct poll_table_struct *wait)
162 {
163 struct iio_dev *indio_dev = filp->private_data;
164 struct iio_buffer *rb = indio_dev->buffer;
165
166 if (!indio_dev->info)
167 return 0;
168
169 poll_wait(filp, &rb->pollq, wait);
170 if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
171 return POLLIN | POLLRDNORM;
172 return 0;
173 }
174
175 /**
176 * iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
177 * @indio_dev: The IIO device
178 *
179 * Wakes up the event waitqueue used for poll(). Should usually
180 * be called when the device is unregistered.
181 */
182 void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
183 {
184 if (!indio_dev->buffer)
185 return;
186
187 wake_up(&indio_dev->buffer->pollq);
188 }
189
190 void iio_buffer_init(struct iio_buffer *buffer)
191 {
192 INIT_LIST_HEAD(&buffer->demux_list);
193 INIT_LIST_HEAD(&buffer->buffer_list);
194 init_waitqueue_head(&buffer->pollq);
195 kref_init(&buffer->ref);
196 buffer->watermark = 1;
197 }
198 EXPORT_SYMBOL(iio_buffer_init);
199
200 static ssize_t iio_show_scan_index(struct device *dev,
201 struct device_attribute *attr,
202 char *buf)
203 {
204 return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
205 }
206
207 static ssize_t iio_show_fixed_type(struct device *dev,
208 struct device_attribute *attr,
209 char *buf)
210 {
211 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
212 u8 type = this_attr->c->scan_type.endianness;
213
214 if (type == IIO_CPU) {
215 #ifdef __LITTLE_ENDIAN
216 type = IIO_LE;
217 #else
218 type = IIO_BE;
219 #endif
220 }
221 if (this_attr->c->scan_type.repeat > 1)
222 return sprintf(buf, "%s:%c%d/%dX%d>>%u\n",
223 iio_endian_prefix[type],
224 this_attr->c->scan_type.sign,
225 this_attr->c->scan_type.realbits,
226 this_attr->c->scan_type.storagebits,
227 this_attr->c->scan_type.repeat,
228 this_attr->c->scan_type.shift);
229 else
230 return sprintf(buf, "%s:%c%d/%d>>%u\n",
231 iio_endian_prefix[type],
232 this_attr->c->scan_type.sign,
233 this_attr->c->scan_type.realbits,
234 this_attr->c->scan_type.storagebits,
235 this_attr->c->scan_type.shift);
236 }
237
238 static ssize_t iio_scan_el_show(struct device *dev,
239 struct device_attribute *attr,
240 char *buf)
241 {
242 int ret;
243 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
244
245 /* Ensure ret is 0 or 1. */
246 ret = !!test_bit(to_iio_dev_attr(attr)->address,
247 indio_dev->buffer->scan_mask);
248
249 return sprintf(buf, "%d\n", ret);
250 }
251
252 /* Note NULL used as error indicator as it doesn't make sense. */
253 static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
254 unsigned int masklength,
255 const unsigned long *mask,
256 bool strict)
257 {
258 if (bitmap_empty(mask, masklength))
259 return NULL;
260 while (*av_masks) {
261 if (strict) {
262 if (bitmap_equal(mask, av_masks, masklength))
263 return av_masks;
264 } else {
265 if (bitmap_subset(mask, av_masks, masklength))
266 return av_masks;
267 }
268 av_masks += BITS_TO_LONGS(masklength);
269 }
270 return NULL;
271 }
272
273 static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
274 const unsigned long *mask)
275 {
276 if (!indio_dev->setup_ops->validate_scan_mask)
277 return true;
278
279 return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
280 }
281
282 /**
283 * iio_scan_mask_set() - set particular bit in the scan mask
284 * @indio_dev: the iio device
285 * @buffer: the buffer whose scan mask we are interested in
286 * @bit: the bit to be set.
287 *
288 * Note that at this point we have no way of knowing what other
289 * buffers might request, hence this code only verifies that the
290 * individual buffers request is plausible.
291 */
292 static int iio_scan_mask_set(struct iio_dev *indio_dev,
293 struct iio_buffer *buffer, int bit)
294 {
295 const unsigned long *mask;
296 unsigned long *trialmask;
297
298 trialmask = kmalloc(sizeof(*trialmask)*
299 BITS_TO_LONGS(indio_dev->masklength),
300 GFP_KERNEL);
301
302 if (trialmask == NULL)
303 return -ENOMEM;
304 if (!indio_dev->masklength) {
305 WARN(1, "Trying to set scanmask prior to registering buffer\n");
306 goto err_invalid_mask;
307 }
308 bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
309 set_bit(bit, trialmask);
310
311 if (!iio_validate_scan_mask(indio_dev, trialmask))
312 goto err_invalid_mask;
313
314 if (indio_dev->available_scan_masks) {
315 mask = iio_scan_mask_match(indio_dev->available_scan_masks,
316 indio_dev->masklength,
317 trialmask, false);
318 if (!mask)
319 goto err_invalid_mask;
320 }
321 bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
322
323 kfree(trialmask);
324
325 return 0;
326
327 err_invalid_mask:
328 kfree(trialmask);
329 return -EINVAL;
330 }
331
332 static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
333 {
334 clear_bit(bit, buffer->scan_mask);
335 return 0;
336 }
337
338 static ssize_t iio_scan_el_store(struct device *dev,
339 struct device_attribute *attr,
340 const char *buf,
341 size_t len)
342 {
343 int ret;
344 bool state;
345 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
346 struct iio_buffer *buffer = indio_dev->buffer;
347 struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
348
349 ret = strtobool(buf, &state);
350 if (ret < 0)
351 return ret;
352 mutex_lock(&indio_dev->mlock);
353 if (iio_buffer_is_active(indio_dev->buffer)) {
354 ret = -EBUSY;
355 goto error_ret;
356 }
357 ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
358 if (ret < 0)
359 goto error_ret;
360 if (!state && ret) {
361 ret = iio_scan_mask_clear(buffer, this_attr->address);
362 if (ret)
363 goto error_ret;
364 } else if (state && !ret) {
365 ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
366 if (ret)
367 goto error_ret;
368 }
369
370 error_ret:
371 mutex_unlock(&indio_dev->mlock);
372
373 return ret < 0 ? ret : len;
374
375 }
376
377 static ssize_t iio_scan_el_ts_show(struct device *dev,
378 struct device_attribute *attr,
379 char *buf)
380 {
381 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
382 return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp);
383 }
384
385 static ssize_t iio_scan_el_ts_store(struct device *dev,
386 struct device_attribute *attr,
387 const char *buf,
388 size_t len)
389 {
390 int ret;
391 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
392 bool state;
393
394 ret = strtobool(buf, &state);
395 if (ret < 0)
396 return ret;
397
398 mutex_lock(&indio_dev->mlock);
399 if (iio_buffer_is_active(indio_dev->buffer)) {
400 ret = -EBUSY;
401 goto error_ret;
402 }
403 indio_dev->buffer->scan_timestamp = state;
404 error_ret:
405 mutex_unlock(&indio_dev->mlock);
406
407 return ret ? ret : len;
408 }
409
410 static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
411 const struct iio_chan_spec *chan)
412 {
413 int ret, attrcount = 0;
414 struct iio_buffer *buffer = indio_dev->buffer;
415
416 ret = __iio_add_chan_devattr("index",
417 chan,
418 &iio_show_scan_index,
419 NULL,
420 0,
421 IIO_SEPARATE,
422 &indio_dev->dev,
423 &buffer->scan_el_dev_attr_list);
424 if (ret)
425 return ret;
426 attrcount++;
427 ret = __iio_add_chan_devattr("type",
428 chan,
429 &iio_show_fixed_type,
430 NULL,
431 0,
432 0,
433 &indio_dev->dev,
434 &buffer->scan_el_dev_attr_list);
435 if (ret)
436 return ret;
437 attrcount++;
438 if (chan->type != IIO_TIMESTAMP)
439 ret = __iio_add_chan_devattr("en",
440 chan,
441 &iio_scan_el_show,
442 &iio_scan_el_store,
443 chan->scan_index,
444 0,
445 &indio_dev->dev,
446 &buffer->scan_el_dev_attr_list);
447 else
448 ret = __iio_add_chan_devattr("en",
449 chan,
450 &iio_scan_el_ts_show,
451 &iio_scan_el_ts_store,
452 chan->scan_index,
453 0,
454 &indio_dev->dev,
455 &buffer->scan_el_dev_attr_list);
456 if (ret)
457 return ret;
458 attrcount++;
459 ret = attrcount;
460 return ret;
461 }
462
463 static ssize_t iio_buffer_read_length(struct device *dev,
464 struct device_attribute *attr,
465 char *buf)
466 {
467 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
468 struct iio_buffer *buffer = indio_dev->buffer;
469
470 return sprintf(buf, "%d\n", buffer->length);
471 }
472
473 static ssize_t iio_buffer_write_length(struct device *dev,
474 struct device_attribute *attr,
475 const char *buf, size_t len)
476 {
477 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
478 struct iio_buffer *buffer = indio_dev->buffer;
479 unsigned int val;
480 int ret;
481
482 ret = kstrtouint(buf, 10, &val);
483 if (ret)
484 return ret;
485
486 if (val == buffer->length)
487 return len;
488
489 mutex_lock(&indio_dev->mlock);
490 if (iio_buffer_is_active(indio_dev->buffer)) {
491 ret = -EBUSY;
492 } else {
493 buffer->access->set_length(buffer, val);
494 ret = 0;
495 }
496 if (ret)
497 goto out;
498 if (buffer->length && buffer->length < buffer->watermark)
499 buffer->watermark = buffer->length;
500 out:
501 mutex_unlock(&indio_dev->mlock);
502
503 return ret ? ret : len;
504 }
505
506 static ssize_t iio_buffer_show_enable(struct device *dev,
507 struct device_attribute *attr,
508 char *buf)
509 {
510 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
511 return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer));
512 }
513
514 static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
515 const unsigned long *mask, bool timestamp)
516 {
517 const struct iio_chan_spec *ch;
518 unsigned bytes = 0;
519 int length, i;
520
521 /* How much space will the demuxed element take? */
522 for_each_set_bit(i, mask,
523 indio_dev->masklength) {
524 ch = iio_find_channel_from_si(indio_dev, i);
525 if (ch->scan_type.repeat > 1)
526 length = ch->scan_type.storagebits / 8 *
527 ch->scan_type.repeat;
528 else
529 length = ch->scan_type.storagebits / 8;
530 bytes = ALIGN(bytes, length);
531 bytes += length;
532 }
533 if (timestamp) {
534 ch = iio_find_channel_from_si(indio_dev,
535 indio_dev->scan_index_timestamp);
536 if (ch->scan_type.repeat > 1)
537 length = ch->scan_type.storagebits / 8 *
538 ch->scan_type.repeat;
539 else
540 length = ch->scan_type.storagebits / 8;
541 bytes = ALIGN(bytes, length);
542 bytes += length;
543 }
544 return bytes;
545 }
546
547 static void iio_buffer_activate(struct iio_dev *indio_dev,
548 struct iio_buffer *buffer)
549 {
550 iio_buffer_get(buffer);
551 list_add(&buffer->buffer_list, &indio_dev->buffer_list);
552 }
553
554 static void iio_buffer_deactivate(struct iio_buffer *buffer)
555 {
556 list_del_init(&buffer->buffer_list);
557 wake_up_interruptible(&buffer->pollq);
558 iio_buffer_put(buffer);
559 }
560
561 static void iio_buffer_deactivate_all(struct iio_dev *indio_dev)
562 {
563 struct iio_buffer *buffer, *_buffer;
564
565 list_for_each_entry_safe(buffer, _buffer,
566 &indio_dev->buffer_list, buffer_list)
567 iio_buffer_deactivate(buffer);
568 }
569
570 static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
571 struct iio_buffer *buffer)
572 {
573 unsigned int bytes;
574
575 if (!buffer->access->set_bytes_per_datum)
576 return;
577
578 bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
579 buffer->scan_timestamp);
580
581 buffer->access->set_bytes_per_datum(buffer, bytes);
582 }
583
584 static int iio_buffer_request_update(struct iio_dev *indio_dev,
585 struct iio_buffer *buffer)
586 {
587 int ret;
588
589 iio_buffer_update_bytes_per_datum(indio_dev, buffer);
590 if (buffer->access->request_update) {
591 ret = buffer->access->request_update(buffer);
592 if (ret) {
593 dev_dbg(&indio_dev->dev,
594 "Buffer not started: buffer parameter update failed (%d)\n",
595 ret);
596 return ret;
597 }
598 }
599
600 return 0;
601 }
602
603 static void iio_free_scan_mask(struct iio_dev *indio_dev,
604 const unsigned long *mask)
605 {
606 /* If the mask is dynamically allocated free it, otherwise do nothing */
607 if (!indio_dev->available_scan_masks)
608 kfree(mask);
609 }
610
611 struct iio_device_config {
612 unsigned int mode;
613 const unsigned long *scan_mask;
614 unsigned int scan_bytes;
615 bool scan_timestamp;
616 };
617
618 static int iio_verify_update(struct iio_dev *indio_dev,
619 struct iio_buffer *insert_buffer, struct iio_buffer *remove_buffer,
620 struct iio_device_config *config)
621 {
622 unsigned long *compound_mask;
623 const unsigned long *scan_mask;
624 bool strict_scanmask = false;
625 struct iio_buffer *buffer;
626 bool scan_timestamp;
627 unsigned int modes;
628
629 memset(config, 0, sizeof(*config));
630
631 /*
632 * If there is just one buffer and we are removing it there is nothing
633 * to verify.
634 */
635 if (remove_buffer && !insert_buffer &&
636 list_is_singular(&indio_dev->buffer_list))
637 return 0;
638
639 modes = indio_dev->modes;
640
641 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
642 if (buffer == remove_buffer)
643 continue;
644 modes &= buffer->access->modes;
645 }
646
647 if (insert_buffer)
648 modes &= insert_buffer->access->modes;
649
650 /* Definitely possible for devices to support both of these. */
651 if ((modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
652 config->mode = INDIO_BUFFER_TRIGGERED;
653 } else if (modes & INDIO_BUFFER_HARDWARE) {
654 /*
655 * Keep things simple for now and only allow a single buffer to
656 * be connected in hardware mode.
657 */
658 if (insert_buffer && !list_empty(&indio_dev->buffer_list))
659 return -EINVAL;
660 config->mode = INDIO_BUFFER_HARDWARE;
661 strict_scanmask = true;
662 } else if (modes & INDIO_BUFFER_SOFTWARE) {
663 config->mode = INDIO_BUFFER_SOFTWARE;
664 } else {
665 /* Can only occur on first buffer */
666 if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
667 dev_dbg(&indio_dev->dev, "Buffer not started: no trigger\n");
668 return -EINVAL;
669 }
670
671 /* What scan mask do we actually have? */
672 compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
673 sizeof(long), GFP_KERNEL);
674 if (compound_mask == NULL)
675 return -ENOMEM;
676
677 scan_timestamp = false;
678
679 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
680 if (buffer == remove_buffer)
681 continue;
682 bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
683 indio_dev->masklength);
684 scan_timestamp |= buffer->scan_timestamp;
685 }
686
687 if (insert_buffer) {
688 bitmap_or(compound_mask, compound_mask,
689 insert_buffer->scan_mask, indio_dev->masklength);
690 scan_timestamp |= insert_buffer->scan_timestamp;
691 }
692
693 if (indio_dev->available_scan_masks) {
694 scan_mask = iio_scan_mask_match(indio_dev->available_scan_masks,
695 indio_dev->masklength,
696 compound_mask,
697 strict_scanmask);
698 kfree(compound_mask);
699 if (scan_mask == NULL)
700 return -EINVAL;
701 } else {
702 scan_mask = compound_mask;
703 }
704
705 config->scan_bytes = iio_compute_scan_bytes(indio_dev,
706 scan_mask, scan_timestamp);
707 config->scan_mask = scan_mask;
708 config->scan_timestamp = scan_timestamp;
709
710 return 0;
711 }
712
713 static int iio_enable_buffers(struct iio_dev *indio_dev,
714 struct iio_device_config *config)
715 {
716 int ret;
717
718 indio_dev->active_scan_mask = config->scan_mask;
719 indio_dev->scan_timestamp = config->scan_timestamp;
720 indio_dev->scan_bytes = config->scan_bytes;
721
722 iio_update_demux(indio_dev);
723
724 /* Wind up again */
725 if (indio_dev->setup_ops->preenable) {
726 ret = indio_dev->setup_ops->preenable(indio_dev);
727 if (ret) {
728 dev_dbg(&indio_dev->dev,
729 "Buffer not started: buffer preenable failed (%d)\n", ret);
730 goto err_undo_config;
731 }
732 }
733
734 if (indio_dev->info->update_scan_mode) {
735 ret = indio_dev->info
736 ->update_scan_mode(indio_dev,
737 indio_dev->active_scan_mask);
738 if (ret < 0) {
739 dev_dbg(&indio_dev->dev,
740 "Buffer not started: update scan mode failed (%d)\n",
741 ret);
742 goto err_run_postdisable;
743 }
744 }
745
746 indio_dev->currentmode = config->mode;
747
748 if (indio_dev->setup_ops->postenable) {
749 ret = indio_dev->setup_ops->postenable(indio_dev);
750 if (ret) {
751 dev_dbg(&indio_dev->dev,
752 "Buffer not started: postenable failed (%d)\n", ret);
753 goto err_run_postdisable;
754 }
755 }
756
757 return 0;
758
759 err_run_postdisable:
760 indio_dev->currentmode = INDIO_DIRECT_MODE;
761 if (indio_dev->setup_ops->postdisable)
762 indio_dev->setup_ops->postdisable(indio_dev);
763 err_undo_config:
764 indio_dev->active_scan_mask = NULL;
765
766 return ret;
767 }
768
769 static int iio_disable_buffers(struct iio_dev *indio_dev)
770 {
771 int ret = 0;
772 int ret2;
773
774 /* Wind down existing buffers - iff there are any */
775 if (list_empty(&indio_dev->buffer_list))
776 return 0;
777
778 /*
779 * If things go wrong at some step in disable we still need to continue
780 * to perform the other steps, otherwise we leave the device in a
781 * inconsistent state. We return the error code for the first error we
782 * encountered.
783 */
784
785 if (indio_dev->setup_ops->predisable) {
786 ret2 = indio_dev->setup_ops->predisable(indio_dev);
787 if (ret2 && !ret)
788 ret = ret2;
789 }
790
791 indio_dev->currentmode = INDIO_DIRECT_MODE;
792
793 if (indio_dev->setup_ops->postdisable) {
794 ret2 = indio_dev->setup_ops->postdisable(indio_dev);
795 if (ret2 && !ret)
796 ret = ret2;
797 }
798
799 iio_free_scan_mask(indio_dev, indio_dev->active_scan_mask);
800 indio_dev->active_scan_mask = NULL;
801
802 return ret;
803 }
804
805 static int __iio_update_buffers(struct iio_dev *indio_dev,
806 struct iio_buffer *insert_buffer,
807 struct iio_buffer *remove_buffer)
808 {
809 struct iio_device_config new_config;
810 int ret;
811
812 ret = iio_verify_update(indio_dev, insert_buffer, remove_buffer,
813 &new_config);
814 if (ret)
815 return ret;
816
817 if (insert_buffer) {
818 ret = iio_buffer_request_update(indio_dev, insert_buffer);
819 if (ret)
820 goto err_free_config;
821 }
822
823 ret = iio_disable_buffers(indio_dev);
824 if (ret)
825 goto err_deactivate_all;
826
827 if (remove_buffer)
828 iio_buffer_deactivate(remove_buffer);
829 if (insert_buffer)
830 iio_buffer_activate(indio_dev, insert_buffer);
831
832 /* If no buffers in list, we are done */
833 if (list_empty(&indio_dev->buffer_list))
834 return 0;
835
836 ret = iio_enable_buffers(indio_dev, &new_config);
837 if (ret)
838 goto err_deactivate_all;
839
840 return 0;
841
842 err_deactivate_all:
843 /*
844 * We've already verified that the config is valid earlier. If things go
845 * wrong in either enable or disable the most likely reason is an IO
846 * error from the device. In this case there is no good recovery
847 * strategy. Just make sure to disable everything and leave the device
848 * in a sane state. With a bit of luck the device might come back to
849 * life again later and userspace can try again.
850 */
851 iio_buffer_deactivate_all(indio_dev);
852
853 err_free_config:
854 iio_free_scan_mask(indio_dev, new_config.scan_mask);
855 return ret;
856 }
857
858 int iio_update_buffers(struct iio_dev *indio_dev,
859 struct iio_buffer *insert_buffer,
860 struct iio_buffer *remove_buffer)
861 {
862 int ret;
863
864 if (insert_buffer == remove_buffer)
865 return 0;
866
867 mutex_lock(&indio_dev->info_exist_lock);
868 mutex_lock(&indio_dev->mlock);
869
870 if (insert_buffer && iio_buffer_is_active(insert_buffer))
871 insert_buffer = NULL;
872
873 if (remove_buffer && !iio_buffer_is_active(remove_buffer))
874 remove_buffer = NULL;
875
876 if (!insert_buffer && !remove_buffer) {
877 ret = 0;
878 goto out_unlock;
879 }
880
881 if (indio_dev->info == NULL) {
882 ret = -ENODEV;
883 goto out_unlock;
884 }
885
886 ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
887
888 out_unlock:
889 mutex_unlock(&indio_dev->mlock);
890 mutex_unlock(&indio_dev->info_exist_lock);
891
892 return ret;
893 }
894 EXPORT_SYMBOL_GPL(iio_update_buffers);
895
896 void iio_disable_all_buffers(struct iio_dev *indio_dev)
897 {
898 iio_disable_buffers(indio_dev);
899 iio_buffer_deactivate_all(indio_dev);
900 }
901
902 static ssize_t iio_buffer_store_enable(struct device *dev,
903 struct device_attribute *attr,
904 const char *buf,
905 size_t len)
906 {
907 int ret;
908 bool requested_state;
909 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
910 bool inlist;
911
912 ret = strtobool(buf, &requested_state);
913 if (ret < 0)
914 return ret;
915
916 mutex_lock(&indio_dev->mlock);
917
918 /* Find out if it is in the list */
919 inlist = iio_buffer_is_active(indio_dev->buffer);
920 /* Already in desired state */
921 if (inlist == requested_state)
922 goto done;
923
924 if (requested_state)
925 ret = __iio_update_buffers(indio_dev,
926 indio_dev->buffer, NULL);
927 else
928 ret = __iio_update_buffers(indio_dev,
929 NULL, indio_dev->buffer);
930
931 done:
932 mutex_unlock(&indio_dev->mlock);
933 return (ret < 0) ? ret : len;
934 }
935
936 static const char * const iio_scan_elements_group_name = "scan_elements";
937
938 static ssize_t iio_buffer_show_watermark(struct device *dev,
939 struct device_attribute *attr,
940 char *buf)
941 {
942 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
943 struct iio_buffer *buffer = indio_dev->buffer;
944
945 return sprintf(buf, "%u\n", buffer->watermark);
946 }
947
948 static ssize_t iio_buffer_store_watermark(struct device *dev,
949 struct device_attribute *attr,
950 const char *buf,
951 size_t len)
952 {
953 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
954 struct iio_buffer *buffer = indio_dev->buffer;
955 unsigned int val;
956 int ret;
957
958 ret = kstrtouint(buf, 10, &val);
959 if (ret)
960 return ret;
961 if (!val)
962 return -EINVAL;
963
964 mutex_lock(&indio_dev->mlock);
965
966 if (val > buffer->length) {
967 ret = -EINVAL;
968 goto out;
969 }
970
971 if (iio_buffer_is_active(indio_dev->buffer)) {
972 ret = -EBUSY;
973 goto out;
974 }
975
976 buffer->watermark = val;
977
978 if (indio_dev->info->hwfifo_set_watermark)
979 indio_dev->info->hwfifo_set_watermark(indio_dev, val);
980 out:
981 mutex_unlock(&indio_dev->mlock);
982
983 return ret ? ret : len;
984 }
985
986 static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
987 iio_buffer_write_length);
988 static struct device_attribute dev_attr_length_ro = __ATTR(length,
989 S_IRUGO, iio_buffer_read_length, NULL);
990 static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
991 iio_buffer_show_enable, iio_buffer_store_enable);
992 static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
993 iio_buffer_show_watermark, iio_buffer_store_watermark);
994
995 static struct attribute *iio_buffer_attrs[] = {
996 &dev_attr_length.attr,
997 &dev_attr_enable.attr,
998 &dev_attr_watermark.attr,
999 };
1000
1001 int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
1002 {
1003 struct iio_dev_attr *p;
1004 struct attribute **attr;
1005 struct iio_buffer *buffer = indio_dev->buffer;
1006 int ret, i, attrn, attrcount, attrcount_orig = 0;
1007 const struct iio_chan_spec *channels;
1008
1009 channels = indio_dev->channels;
1010 if (channels) {
1011 int ml = indio_dev->masklength;
1012
1013 for (i = 0; i < indio_dev->num_channels; i++)
1014 ml = max(ml, channels[i].scan_index + 1);
1015 indio_dev->masklength = ml;
1016 }
1017
1018 if (!buffer)
1019 return 0;
1020
1021 attrcount = 0;
1022 if (buffer->attrs) {
1023 while (buffer->attrs[attrcount] != NULL)
1024 attrcount++;
1025 }
1026
1027 attr = kcalloc(attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1,
1028 sizeof(struct attribute *), GFP_KERNEL);
1029 if (!attr)
1030 return -ENOMEM;
1031
1032 memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs));
1033 if (!buffer->access->set_length)
1034 attr[0] = &dev_attr_length_ro.attr;
1035
1036 if (buffer->attrs)
1037 memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs,
1038 sizeof(struct attribute *) * attrcount);
1039
1040 attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL;
1041
1042 buffer->buffer_group.name = "buffer";
1043 buffer->buffer_group.attrs = attr;
1044
1045 indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group;
1046
1047 if (buffer->scan_el_attrs != NULL) {
1048 attr = buffer->scan_el_attrs->attrs;
1049 while (*attr++ != NULL)
1050 attrcount_orig++;
1051 }
1052 attrcount = attrcount_orig;
1053 INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
1054 channels = indio_dev->channels;
1055 if (channels) {
1056 /* new magic */
1057 for (i = 0; i < indio_dev->num_channels; i++) {
1058 if (channels[i].scan_index < 0)
1059 continue;
1060
1061 ret = iio_buffer_add_channel_sysfs(indio_dev,
1062 &channels[i]);
1063 if (ret < 0)
1064 goto error_cleanup_dynamic;
1065 attrcount += ret;
1066 if (channels[i].type == IIO_TIMESTAMP)
1067 indio_dev->scan_index_timestamp =
1068 channels[i].scan_index;
1069 }
1070 if (indio_dev->masklength && buffer->scan_mask == NULL) {
1071 buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
1072 sizeof(*buffer->scan_mask),
1073 GFP_KERNEL);
1074 if (buffer->scan_mask == NULL) {
1075 ret = -ENOMEM;
1076 goto error_cleanup_dynamic;
1077 }
1078 }
1079 }
1080
1081 buffer->scan_el_group.name = iio_scan_elements_group_name;
1082
1083 buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
1084 sizeof(buffer->scan_el_group.attrs[0]),
1085 GFP_KERNEL);
1086 if (buffer->scan_el_group.attrs == NULL) {
1087 ret = -ENOMEM;
1088 goto error_free_scan_mask;
1089 }
1090 if (buffer->scan_el_attrs)
1091 memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
1092 sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
1093 attrn = attrcount_orig;
1094
1095 list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
1096 buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
1097 indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
1098
1099 return 0;
1100
1101 error_free_scan_mask:
1102 kfree(buffer->scan_mask);
1103 error_cleanup_dynamic:
1104 iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
1105 kfree(indio_dev->buffer->buffer_group.attrs);
1106
1107 return ret;
1108 }
1109
1110 void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev)
1111 {
1112 if (!indio_dev->buffer)
1113 return;
1114
1115 kfree(indio_dev->buffer->scan_mask);
1116 kfree(indio_dev->buffer->buffer_group.attrs);
1117 kfree(indio_dev->buffer->scan_el_group.attrs);
1118 iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
1119 }
1120
1121 /**
1122 * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
1123 * @indio_dev: the iio device
1124 * @mask: scan mask to be checked
1125 *
1126 * Return true if exactly one bit is set in the scan mask, false otherwise. It
1127 * can be used for devices where only one channel can be active for sampling at
1128 * a time.
1129 */
1130 bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
1131 const unsigned long *mask)
1132 {
1133 return bitmap_weight(mask, indio_dev->masklength) == 1;
1134 }
1135 EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
1136
1137 int iio_scan_mask_query(struct iio_dev *indio_dev,
1138 struct iio_buffer *buffer, int bit)
1139 {
1140 if (bit > indio_dev->masklength)
1141 return -EINVAL;
1142
1143 if (!buffer->scan_mask)
1144 return 0;
1145
1146 /* Ensure return value is 0 or 1. */
1147 return !!test_bit(bit, buffer->scan_mask);
1148 };
1149 EXPORT_SYMBOL_GPL(iio_scan_mask_query);
1150
1151 /**
1152 * struct iio_demux_table - table describing demux memcpy ops
1153 * @from: index to copy from
1154 * @to: index to copy to
1155 * @length: how many bytes to copy
1156 * @l: list head used for management
1157 */
1158 struct iio_demux_table {
1159 unsigned from;
1160 unsigned to;
1161 unsigned length;
1162 struct list_head l;
1163 };
1164
1165 static const void *iio_demux(struct iio_buffer *buffer,
1166 const void *datain)
1167 {
1168 struct iio_demux_table *t;
1169
1170 if (list_empty(&buffer->demux_list))
1171 return datain;
1172 list_for_each_entry(t, &buffer->demux_list, l)
1173 memcpy(buffer->demux_bounce + t->to,
1174 datain + t->from, t->length);
1175
1176 return buffer->demux_bounce;
1177 }
1178
1179 static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
1180 {
1181 const void *dataout = iio_demux(buffer, data);
1182 int ret;
1183
1184 ret = buffer->access->store_to(buffer, dataout);
1185 if (ret)
1186 return ret;
1187
1188 /*
1189 * We can't just test for watermark to decide if we wake the poll queue
1190 * because read may request less samples than the watermark.
1191 */
1192 wake_up_interruptible_poll(&buffer->pollq, POLLIN | POLLRDNORM);
1193 return 0;
1194 }
1195
1196 static void iio_buffer_demux_free(struct iio_buffer *buffer)
1197 {
1198 struct iio_demux_table *p, *q;
1199 list_for_each_entry_safe(p, q, &buffer->demux_list, l) {
1200 list_del(&p->l);
1201 kfree(p);
1202 }
1203 }
1204
1205
1206 int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
1207 {
1208 int ret;
1209 struct iio_buffer *buf;
1210
1211 list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) {
1212 ret = iio_push_to_buffer(buf, data);
1213 if (ret < 0)
1214 return ret;
1215 }
1216
1217 return 0;
1218 }
1219 EXPORT_SYMBOL_GPL(iio_push_to_buffers);
1220
1221 static int iio_buffer_add_demux(struct iio_buffer *buffer,
1222 struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc,
1223 unsigned int length)
1224 {
1225
1226 if (*p && (*p)->from + (*p)->length == in_loc &&
1227 (*p)->to + (*p)->length == out_loc) {
1228 (*p)->length += length;
1229 } else {
1230 *p = kmalloc(sizeof(**p), GFP_KERNEL);
1231 if (*p == NULL)
1232 return -ENOMEM;
1233 (*p)->from = in_loc;
1234 (*p)->to = out_loc;
1235 (*p)->length = length;
1236 list_add_tail(&(*p)->l, &buffer->demux_list);
1237 }
1238
1239 return 0;
1240 }
1241
1242 static int iio_buffer_update_demux(struct iio_dev *indio_dev,
1243 struct iio_buffer *buffer)
1244 {
1245 const struct iio_chan_spec *ch;
1246 int ret, in_ind = -1, out_ind, length;
1247 unsigned in_loc = 0, out_loc = 0;
1248 struct iio_demux_table *p = NULL;
1249
1250 /* Clear out any old demux */
1251 iio_buffer_demux_free(buffer);
1252 kfree(buffer->demux_bounce);
1253 buffer->demux_bounce = NULL;
1254
1255 /* First work out which scan mode we will actually have */
1256 if (bitmap_equal(indio_dev->active_scan_mask,
1257 buffer->scan_mask,
1258 indio_dev->masklength))
1259 return 0;
1260
1261 /* Now we have the two masks, work from least sig and build up sizes */
1262 for_each_set_bit(out_ind,
1263 buffer->scan_mask,
1264 indio_dev->masklength) {
1265 in_ind = find_next_bit(indio_dev->active_scan_mask,
1266 indio_dev->masklength,
1267 in_ind + 1);
1268 while (in_ind != out_ind) {
1269 in_ind = find_next_bit(indio_dev->active_scan_mask,
1270 indio_dev->masklength,
1271 in_ind + 1);
1272 ch = iio_find_channel_from_si(indio_dev, in_ind);
1273 if (ch->scan_type.repeat > 1)
1274 length = ch->scan_type.storagebits / 8 *
1275 ch->scan_type.repeat;
1276 else
1277 length = ch->scan_type.storagebits / 8;
1278 /* Make sure we are aligned */
1279 in_loc = roundup(in_loc, length) + length;
1280 }
1281 ch = iio_find_channel_from_si(indio_dev, in_ind);
1282 if (ch->scan_type.repeat > 1)
1283 length = ch->scan_type.storagebits / 8 *
1284 ch->scan_type.repeat;
1285 else
1286 length = ch->scan_type.storagebits / 8;
1287 out_loc = roundup(out_loc, length);
1288 in_loc = roundup(in_loc, length);
1289 ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
1290 if (ret)
1291 goto error_clear_mux_table;
1292 out_loc += length;
1293 in_loc += length;
1294 }
1295 /* Relies on scan_timestamp being last */
1296 if (buffer->scan_timestamp) {
1297 ch = iio_find_channel_from_si(indio_dev,
1298 indio_dev->scan_index_timestamp);
1299 if (ch->scan_type.repeat > 1)
1300 length = ch->scan_type.storagebits / 8 *
1301 ch->scan_type.repeat;
1302 else
1303 length = ch->scan_type.storagebits / 8;
1304 out_loc = roundup(out_loc, length);
1305 in_loc = roundup(in_loc, length);
1306 ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
1307 if (ret)
1308 goto error_clear_mux_table;
1309 out_loc += length;
1310 in_loc += length;
1311 }
1312 buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
1313 if (buffer->demux_bounce == NULL) {
1314 ret = -ENOMEM;
1315 goto error_clear_mux_table;
1316 }
1317 return 0;
1318
1319 error_clear_mux_table:
1320 iio_buffer_demux_free(buffer);
1321
1322 return ret;
1323 }
1324
1325 int iio_update_demux(struct iio_dev *indio_dev)
1326 {
1327 struct iio_buffer *buffer;
1328 int ret;
1329
1330 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
1331 ret = iio_buffer_update_demux(indio_dev, buffer);
1332 if (ret < 0)
1333 goto error_clear_mux_table;
1334 }
1335 return 0;
1336
1337 error_clear_mux_table:
1338 list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
1339 iio_buffer_demux_free(buffer);
1340
1341 return ret;
1342 }
1343 EXPORT_SYMBOL_GPL(iio_update_demux);
1344
1345 /**
1346 * iio_buffer_release() - Free a buffer's resources
1347 * @ref: Pointer to the kref embedded in the iio_buffer struct
1348 *
1349 * This function is called when the last reference to the buffer has been
1350 * dropped. It will typically free all resources allocated by the buffer. Do not
1351 * call this function manually, always use iio_buffer_put() when done using a
1352 * buffer.
1353 */
1354 static void iio_buffer_release(struct kref *ref)
1355 {
1356 struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
1357
1358 buffer->access->release(buffer);
1359 }
1360
1361 /**
1362 * iio_buffer_get() - Grab a reference to the buffer
1363 * @buffer: The buffer to grab a reference for, may be NULL
1364 *
1365 * Returns the pointer to the buffer that was passed into the function.
1366 */
1367 struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
1368 {
1369 if (buffer)
1370 kref_get(&buffer->ref);
1371
1372 return buffer;
1373 }
1374 EXPORT_SYMBOL_GPL(iio_buffer_get);
1375
1376 /**
1377 * iio_buffer_put() - Release the reference to the buffer
1378 * @buffer: The buffer to release the reference for, may be NULL
1379 */
1380 void iio_buffer_put(struct iio_buffer *buffer)
1381 {
1382 if (buffer)
1383 kref_put(&buffer->ref, iio_buffer_release);
1384 }
1385 EXPORT_SYMBOL_GPL(iio_buffer_put);
Linux with added FPC-III support