1 /*
2 module/drivers.c
3 functions for manipulating drivers
4
5 COMEDI - Linux Control and Measurement Device Interface
6 Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21
22 */
23
24 #define _GNU_SOURCE
25
26 #define __NO_VERSION__
27 #include "comedi_fops.h"
28 #include <linux/device.h>
29 #include <linux/module.h>
30 #include <linux/pci.h>
31 #include <linux/usb.h>
32 #include <linux/errno.h>
33 #include <linux/kernel.h>
34 #include <linux/sched.h>
35 #include <linux/fcntl.h>
36 #include <linux/delay.h>
37 #include <linux/ioport.h>
38 #include <linux/mm.h>
39 #include <linux/slab.h>
40 #include <linux/highmem.h> /* for SuSE brokenness */
41 #include <linux/vmalloc.h>
42 #include <linux/cdev.h>
43 #include <linux/dma-mapping.h>
44 #include <linux/io.h>
45
46 #include "comedidev.h"
47 #include "internal.h"
48
49 static int postconfig(struct comedi_device *dev);
50 static int insn_rw_emulate_bits(struct comedi_device *dev,
51 struct comedi_subdevice *s,
52 struct comedi_insn *insn, unsigned int *data);
53 static void *comedi_recognize(struct comedi_driver *driv, const char *name);
54 static void comedi_report_boards(struct comedi_driver *driv);
55 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s);
56
57 struct comedi_driver *comedi_drivers;
58
cleanup_device(struct comedi_device * dev)59 static void cleanup_device(struct comedi_device *dev)
60 {
61 int i;
62 struct comedi_subdevice *s;
63
64 if (dev->subdevices) {
65 for (i = 0; i < dev->n_subdevices; i++) {
66 s = dev->subdevices + i;
67 comedi_free_subdevice_minor(s);
68 if (s->async) {
69 comedi_buf_alloc(dev, s, 0);
70 kfree(s->async);
71 }
72 }
73 kfree(dev->subdevices);
74 dev->subdevices = NULL;
75 dev->n_subdevices = 0;
76 }
77 kfree(dev->private);
78 dev->private = NULL;
79 dev->driver = NULL;
80 dev->board_name = NULL;
81 dev->board_ptr = NULL;
82 dev->iobase = 0;
83 dev->irq = 0;
84 dev->read_subdev = NULL;
85 dev->write_subdev = NULL;
86 dev->open = NULL;
87 dev->close = NULL;
88 comedi_set_hw_dev(dev, NULL);
89 }
90
__comedi_device_detach(struct comedi_device * dev)91 static void __comedi_device_detach(struct comedi_device *dev)
92 {
93 dev->attached = 0;
94 if (dev->driver)
95 dev->driver->detach(dev);
96 else
97 printk(KERN_WARNING
98 "BUG: dev->driver=NULL in comedi_device_detach()\n");
99 cleanup_device(dev);
100 }
101
comedi_device_detach(struct comedi_device * dev)102 void comedi_device_detach(struct comedi_device *dev)
103 {
104 if (!dev->attached)
105 return;
106 __comedi_device_detach(dev);
107 }
108
comedi_device_attach(struct comedi_device * dev,struct comedi_devconfig * it)109 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
110 {
111 struct comedi_driver *driv;
112 int ret;
113
114 if (dev->attached)
115 return -EBUSY;
116
117 for (driv = comedi_drivers; driv; driv = driv->next) {
118 if (!try_module_get(driv->module)) {
119 printk(KERN_INFO "comedi: failed to increment module count, skipping\n");
120 continue;
121 }
122 if (driv->num_names) {
123 dev->board_ptr = comedi_recognize(driv, it->board_name);
124 if (dev->board_ptr == NULL) {
125 module_put(driv->module);
126 continue;
127 }
128 } else {
129 if (strcmp(driv->driver_name, it->board_name)) {
130 module_put(driv->module);
131 continue;
132 }
133 }
134 /* initialize dev->driver here so
135 * comedi_error() can be called from attach */
136 dev->driver = driv;
137 ret = driv->attach(dev, it);
138 if (ret < 0) {
139 module_put(dev->driver->module);
140 __comedi_device_detach(dev);
141 return ret;
142 }
143 goto attached;
144 }
145
146 /* recognize has failed if we get here */
147 /* report valid board names before returning error */
148 for (driv = comedi_drivers; driv; driv = driv->next) {
149 if (!try_module_get(driv->module)) {
150 printk(KERN_INFO
151 "comedi: failed to increment module count\n");
152 continue;
153 }
154 comedi_report_boards(driv);
155 module_put(driv->module);
156 }
157 return -EIO;
158
159 attached:
160 /* do a little post-config cleanup */
161 ret = postconfig(dev);
162 module_put(dev->driver->module);
163 if (ret < 0) {
164 __comedi_device_detach(dev);
165 return ret;
166 }
167
168 if (!dev->board_name) {
169 printk(KERN_WARNING "BUG: dev->board_name=<%p>\n",
170 dev->board_name);
171 dev->board_name = "BUG";
172 }
173 smp_wmb();
174 dev->attached = 1;
175
176 return 0;
177 }
178
comedi_driver_register(struct comedi_driver * driver)179 int comedi_driver_register(struct comedi_driver *driver)
180 {
181 driver->next = comedi_drivers;
182 comedi_drivers = driver;
183
184 return 0;
185 }
186 EXPORT_SYMBOL(comedi_driver_register);
187
comedi_driver_unregister(struct comedi_driver * driver)188 int comedi_driver_unregister(struct comedi_driver *driver)
189 {
190 struct comedi_driver *prev;
191 int i;
192
193 /* check for devices using this driver */
194 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
195 struct comedi_device_file_info *dev_file_info =
196 comedi_get_device_file_info(i);
197 struct comedi_device *dev;
198
199 if (dev_file_info == NULL)
200 continue;
201 dev = dev_file_info->device;
202
203 mutex_lock(&dev->mutex);
204 if (dev->attached && dev->driver == driver) {
205 if (dev->use_count)
206 printk(KERN_WARNING "BUG! detaching device with use_count=%d\n",
207 dev->use_count);
208 comedi_device_detach(dev);
209 }
210 mutex_unlock(&dev->mutex);
211 }
212
213 if (comedi_drivers == driver) {
214 comedi_drivers = driver->next;
215 return 0;
216 }
217
218 for (prev = comedi_drivers; prev->next; prev = prev->next) {
219 if (prev->next == driver) {
220 prev->next = driver->next;
221 return 0;
222 }
223 }
224 return -EINVAL;
225 }
226 EXPORT_SYMBOL(comedi_driver_unregister);
227
postconfig(struct comedi_device * dev)228 static int postconfig(struct comedi_device *dev)
229 {
230 int i;
231 struct comedi_subdevice *s;
232 struct comedi_async *async = NULL;
233 int ret;
234
235 for (i = 0; i < dev->n_subdevices; i++) {
236 s = dev->subdevices + i;
237
238 if (s->type == COMEDI_SUBD_UNUSED)
239 continue;
240
241 if (s->len_chanlist == 0)
242 s->len_chanlist = 1;
243
244 if (s->do_cmd) {
245 BUG_ON((s->subdev_flags & (SDF_CMD_READ |
246 SDF_CMD_WRITE)) == 0);
247 BUG_ON(!s->do_cmdtest);
248
249 async =
250 kzalloc(sizeof(struct comedi_async), GFP_KERNEL);
251 if (async == NULL) {
252 printk(KERN_INFO
253 "failed to allocate async struct\n");
254 return -ENOMEM;
255 }
256 init_waitqueue_head(&async->wait_head);
257 async->subdevice = s;
258 s->async = async;
259
260 #define DEFAULT_BUF_MAXSIZE (64*1024)
261 #define DEFAULT_BUF_SIZE (64*1024)
262
263 async->max_bufsize = DEFAULT_BUF_MAXSIZE;
264
265 async->prealloc_buf = NULL;
266 async->prealloc_bufsz = 0;
267 if (comedi_buf_alloc(dev, s, DEFAULT_BUF_SIZE) < 0) {
268 printk(KERN_INFO "Buffer allocation failed\n");
269 return -ENOMEM;
270 }
271 if (s->buf_change) {
272 ret = s->buf_change(dev, s, DEFAULT_BUF_SIZE);
273 if (ret < 0)
274 return ret;
275 }
276 comedi_alloc_subdevice_minor(dev, s);
277 }
278
279 if (!s->range_table && !s->range_table_list)
280 s->range_table = &range_unknown;
281
282 if (!s->insn_read && s->insn_bits)
283 s->insn_read = insn_rw_emulate_bits;
284 if (!s->insn_write && s->insn_bits)
285 s->insn_write = insn_rw_emulate_bits;
286
287 if (!s->insn_read)
288 s->insn_read = insn_inval;
289 if (!s->insn_write)
290 s->insn_write = insn_inval;
291 if (!s->insn_bits)
292 s->insn_bits = insn_inval;
293 if (!s->insn_config)
294 s->insn_config = insn_inval;
295
296 if (!s->poll)
297 s->poll = poll_invalid;
298 }
299
300 return 0;
301 }
302
303 /* generic recognize function for drivers
304 * that register their supported board names */
comedi_recognize(struct comedi_driver * driv,const char * name)305 static void *comedi_recognize(struct comedi_driver *driv, const char *name)
306 {
307 unsigned i;
308 const char *const *name_ptr = driv->board_name;
309 for (i = 0; i < driv->num_names; i++) {
310 if (strcmp(*name_ptr, name) == 0)
311 return (void *)name_ptr;
312 name_ptr =
313 (const char *const *)((const char *)name_ptr +
314 driv->offset);
315 }
316
317 return NULL;
318 }
319
comedi_report_boards(struct comedi_driver * driv)320 static void comedi_report_boards(struct comedi_driver *driv)
321 {
322 unsigned int i;
323 const char *const *name_ptr;
324
325 printk(KERN_INFO "comedi: valid board names for %s driver are:\n",
326 driv->driver_name);
327
328 name_ptr = driv->board_name;
329 for (i = 0; i < driv->num_names; i++) {
330 printk(KERN_INFO " %s\n", *name_ptr);
331 name_ptr = (const char **)((char *)name_ptr + driv->offset);
332 }
333
334 if (driv->num_names == 0)
335 printk(KERN_INFO " %s\n", driv->driver_name);
336 }
337
poll_invalid(struct comedi_device * dev,struct comedi_subdevice * s)338 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
339 {
340 return -EINVAL;
341 }
342
insn_inval(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)343 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
344 struct comedi_insn *insn, unsigned int *data)
345 {
346 return -EINVAL;
347 }
348
insn_rw_emulate_bits(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)349 static int insn_rw_emulate_bits(struct comedi_device *dev,
350 struct comedi_subdevice *s,
351 struct comedi_insn *insn, unsigned int *data)
352 {
353 struct comedi_insn new_insn;
354 int ret;
355 static const unsigned channels_per_bitfield = 32;
356
357 unsigned chan = CR_CHAN(insn->chanspec);
358 const unsigned base_bitfield_channel =
359 (chan < channels_per_bitfield) ? 0 : chan;
360 unsigned int new_data[2];
361 memset(new_data, 0, sizeof(new_data));
362 memset(&new_insn, 0, sizeof(new_insn));
363 new_insn.insn = INSN_BITS;
364 new_insn.chanspec = base_bitfield_channel;
365 new_insn.n = 2;
366 new_insn.data = new_data;
367 new_insn.subdev = insn->subdev;
368
369 if (insn->insn == INSN_WRITE) {
370 if (!(s->subdev_flags & SDF_WRITABLE))
371 return -EINVAL;
372 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
373 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
374 : 0; /* bits */
375 }
376
377 ret = s->insn_bits(dev, s, &new_insn, new_data);
378 if (ret < 0)
379 return ret;
380
381 if (insn->insn == INSN_READ)
382 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
383
384 return 1;
385 }
386
uvirt_to_kva(pgd_t * pgd,unsigned long adr)387 static inline unsigned long uvirt_to_kva(pgd_t *pgd, unsigned long adr)
388 {
389 unsigned long ret = 0UL;
390 pmd_t *pmd;
391 pte_t *ptep, pte;
392 pud_t *pud;
393
394 if (!pgd_none(*pgd)) {
395 pud = pud_offset(pgd, adr);
396 pmd = pmd_offset(pud, adr);
397 if (!pmd_none(*pmd)) {
398 ptep = pte_offset_kernel(pmd, adr);
399 pte = *ptep;
400 if (pte_present(pte)) {
401 ret = (unsigned long)
402 page_address(pte_page(pte));
403 ret |= (adr & (PAGE_SIZE - 1));
404 }
405 }
406 }
407 return ret;
408 }
409
kvirt_to_kva(unsigned long adr)410 static inline unsigned long kvirt_to_kva(unsigned long adr)
411 {
412 unsigned long va, kva;
413
414 va = adr;
415 kva = uvirt_to_kva(pgd_offset_k(va), va);
416
417 return kva;
418 }
419
comedi_buf_alloc(struct comedi_device * dev,struct comedi_subdevice * s,unsigned long new_size)420 int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
421 unsigned long new_size)
422 {
423 struct comedi_async *async = s->async;
424
425 /* Round up new_size to multiple of PAGE_SIZE */
426 new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
427
428 /* if no change is required, do nothing */
429 if (async->prealloc_buf && async->prealloc_bufsz == new_size)
430 return 0;
431
432 /* deallocate old buffer */
433 if (async->prealloc_buf) {
434 vunmap(async->prealloc_buf);
435 async->prealloc_buf = NULL;
436 async->prealloc_bufsz = 0;
437 }
438 if (async->buf_page_list) {
439 unsigned i;
440 for (i = 0; i < async->n_buf_pages; ++i) {
441 if (async->buf_page_list[i].virt_addr) {
442 clear_bit(PG_reserved,
443 &(virt_to_page(async->buf_page_list[i].
444 virt_addr)->flags));
445 if (s->async_dma_dir != DMA_NONE) {
446 dma_free_coherent(dev->hw_dev,
447 PAGE_SIZE,
448 async->
449 buf_page_list
450 [i].virt_addr,
451 async->
452 buf_page_list
453 [i].dma_addr);
454 } else {
455 free_page((unsigned long)
456 async->buf_page_list[i].
457 virt_addr);
458 }
459 }
460 }
461 vfree(async->buf_page_list);
462 async->buf_page_list = NULL;
463 async->n_buf_pages = 0;
464 }
465 /* allocate new buffer */
466 if (new_size) {
467 unsigned i = 0;
468 unsigned n_pages = new_size >> PAGE_SHIFT;
469 struct page **pages = NULL;
470
471 async->buf_page_list =
472 vzalloc(sizeof(struct comedi_buf_page) * n_pages);
473 if (async->buf_page_list)
474 pages = vmalloc(sizeof(struct page *) * n_pages);
475
476 if (pages) {
477 for (i = 0; i < n_pages; i++) {
478 if (s->async_dma_dir != DMA_NONE) {
479 async->buf_page_list[i].virt_addr =
480 dma_alloc_coherent(dev->hw_dev,
481 PAGE_SIZE,
482 &async->
483 buf_page_list
484 [i].dma_addr,
485 GFP_KERNEL |
486 __GFP_COMP);
487 } else {
488 async->buf_page_list[i].virt_addr =
489 (void *)
490 get_zeroed_page(GFP_KERNEL);
491 }
492 if (async->buf_page_list[i].virt_addr == NULL)
493 break;
494
495 set_bit(PG_reserved,
496 &(virt_to_page(async->buf_page_list[i].
497 virt_addr)->flags));
498 pages[i] = virt_to_page(async->buf_page_list[i].
499 virt_addr);
500 }
501 }
502 if (i == n_pages) {
503 async->prealloc_buf =
504 #ifdef PAGE_KERNEL_NOCACHE
505 vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
506 #else
507 vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
508 #endif
509 }
510 vfree(pages);
511
512 if (async->prealloc_buf == NULL) {
513 /* Some allocation failed above. */
514 if (async->buf_page_list) {
515 for (i = 0; i < n_pages; i++) {
516 if (async->buf_page_list[i].virt_addr ==
517 NULL) {
518 break;
519 }
520 clear_bit(PG_reserved,
521 &(virt_to_page(async->
522 buf_page_list[i].
523 virt_addr)->flags));
524 if (s->async_dma_dir != DMA_NONE) {
525 dma_free_coherent(dev->hw_dev,
526 PAGE_SIZE,
527 async->
528 buf_page_list
529 [i].virt_addr,
530 async->
531 buf_page_list
532 [i].dma_addr);
533 } else {
534 free_page((unsigned long)
535 async->buf_page_list
536 [i].virt_addr);
537 }
538 }
539 vfree(async->buf_page_list);
540 async->buf_page_list = NULL;
541 }
542 return -ENOMEM;
543 }
544 async->n_buf_pages = n_pages;
545 }
546 async->prealloc_bufsz = new_size;
547
548 return 0;
549 }
550
551 /* munging is applied to data by core as it passes between user
552 * and kernel space */
comedi_buf_munge(struct comedi_async * async,unsigned int num_bytes)553 static unsigned int comedi_buf_munge(struct comedi_async *async,
554 unsigned int num_bytes)
555 {
556 struct comedi_subdevice *s = async->subdevice;
557 unsigned int count = 0;
558 const unsigned num_sample_bytes = bytes_per_sample(s);
559
560 if (s->munge == NULL || (async->cmd.flags & CMDF_RAWDATA)) {
561 async->munge_count += num_bytes;
562 BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
563 return num_bytes;
564 }
565 /* don't munge partial samples */
566 num_bytes -= num_bytes % num_sample_bytes;
567 while (count < num_bytes) {
568 int block_size;
569
570 block_size = num_bytes - count;
571 if (block_size < 0) {
572 printk(KERN_WARNING
573 "%s: %s: bug! block_size is negative\n",
574 __FILE__, __func__);
575 break;
576 }
577 if ((int)(async->munge_ptr + block_size -
578 async->prealloc_bufsz) > 0)
579 block_size = async->prealloc_bufsz - async->munge_ptr;
580
581 s->munge(s->device, s, async->prealloc_buf + async->munge_ptr,
582 block_size, async->munge_chan);
583
584 smp_wmb(); /* barrier insures data is munged in buffer
585 * before munge_count is incremented */
586
587 async->munge_chan += block_size / num_sample_bytes;
588 async->munge_chan %= async->cmd.chanlist_len;
589 async->munge_count += block_size;
590 async->munge_ptr += block_size;
591 async->munge_ptr %= async->prealloc_bufsz;
592 count += block_size;
593 }
594 BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
595 return count;
596 }
597
comedi_buf_write_n_available(struct comedi_async * async)598 unsigned int comedi_buf_write_n_available(struct comedi_async *async)
599 {
600 unsigned int free_end;
601 unsigned int nbytes;
602
603 if (async == NULL)
604 return 0;
605
606 free_end = async->buf_read_count + async->prealloc_bufsz;
607 nbytes = free_end - async->buf_write_alloc_count;
608 nbytes -= nbytes % bytes_per_sample(async->subdevice);
609 /* barrier insures the read of buf_read_count in this
610 query occurs before any following writes to the buffer which
611 might be based on the return value from this query.
612 */
613 smp_mb();
614 return nbytes;
615 }
616
617 /* allocates chunk for the writer from free buffer space */
comedi_buf_write_alloc(struct comedi_async * async,unsigned int nbytes)618 unsigned int comedi_buf_write_alloc(struct comedi_async *async,
619 unsigned int nbytes)
620 {
621 unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
622
623 if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
624 nbytes = free_end - async->buf_write_alloc_count;
625
626 async->buf_write_alloc_count += nbytes;
627 /* barrier insures the read of buf_read_count above occurs before
628 we write data to the write-alloc'ed buffer space */
629 smp_mb();
630 return nbytes;
631 }
632 EXPORT_SYMBOL(comedi_buf_write_alloc);
633
634 /* allocates nothing unless it can completely fulfill the request */
comedi_buf_write_alloc_strict(struct comedi_async * async,unsigned int nbytes)635 unsigned int comedi_buf_write_alloc_strict(struct comedi_async *async,
636 unsigned int nbytes)
637 {
638 unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
639
640 if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
641 nbytes = 0;
642
643 async->buf_write_alloc_count += nbytes;
644 /* barrier insures the read of buf_read_count above occurs before
645 we write data to the write-alloc'ed buffer space */
646 smp_mb();
647 return nbytes;
648 }
649
650 /* transfers a chunk from writer to filled buffer space */
comedi_buf_write_free(struct comedi_async * async,unsigned int nbytes)651 unsigned comedi_buf_write_free(struct comedi_async *async, unsigned int nbytes)
652 {
653 if ((int)(async->buf_write_count + nbytes -
654 async->buf_write_alloc_count) > 0) {
655 printk(KERN_INFO "comedi: attempted to write-free more bytes than have been write-allocated.\n");
656 nbytes = async->buf_write_alloc_count - async->buf_write_count;
657 }
658 async->buf_write_count += nbytes;
659 async->buf_write_ptr += nbytes;
660 comedi_buf_munge(async, async->buf_write_count - async->munge_count);
661 if (async->buf_write_ptr >= async->prealloc_bufsz)
662 async->buf_write_ptr %= async->prealloc_bufsz;
663
664 return nbytes;
665 }
666 EXPORT_SYMBOL(comedi_buf_write_free);
667
668 /* allocates a chunk for the reader from filled (and munged) buffer space */
comedi_buf_read_alloc(struct comedi_async * async,unsigned nbytes)669 unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes)
670 {
671 if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) >
672 0) {
673 nbytes = async->munge_count - async->buf_read_alloc_count;
674 }
675 async->buf_read_alloc_count += nbytes;
676 /* barrier insures read of munge_count occurs before we actually read
677 data out of buffer */
678 smp_rmb();
679 return nbytes;
680 }
681 EXPORT_SYMBOL(comedi_buf_read_alloc);
682
683 /* transfers control of a chunk from reader to free buffer space */
comedi_buf_read_free(struct comedi_async * async,unsigned int nbytes)684 unsigned comedi_buf_read_free(struct comedi_async *async, unsigned int nbytes)
685 {
686 /* barrier insures data has been read out of
687 * buffer before read count is incremented */
688 smp_mb();
689 if ((int)(async->buf_read_count + nbytes -
690 async->buf_read_alloc_count) > 0) {
691 printk(KERN_INFO
692 "comedi: attempted to read-free more bytes than have been read-allocated.\n");
693 nbytes = async->buf_read_alloc_count - async->buf_read_count;
694 }
695 async->buf_read_count += nbytes;
696 async->buf_read_ptr += nbytes;
697 async->buf_read_ptr %= async->prealloc_bufsz;
698 return nbytes;
699 }
700 EXPORT_SYMBOL(comedi_buf_read_free);
701
comedi_buf_memcpy_to(struct comedi_async * async,unsigned int offset,const void * data,unsigned int num_bytes)702 void comedi_buf_memcpy_to(struct comedi_async *async, unsigned int offset,
703 const void *data, unsigned int num_bytes)
704 {
705 unsigned int write_ptr = async->buf_write_ptr + offset;
706
707 if (write_ptr >= async->prealloc_bufsz)
708 write_ptr %= async->prealloc_bufsz;
709
710 while (num_bytes) {
711 unsigned int block_size;
712
713 if (write_ptr + num_bytes > async->prealloc_bufsz)
714 block_size = async->prealloc_bufsz - write_ptr;
715 else
716 block_size = num_bytes;
717
718 memcpy(async->prealloc_buf + write_ptr, data, block_size);
719
720 data += block_size;
721 num_bytes -= block_size;
722
723 write_ptr = 0;
724 }
725 }
726 EXPORT_SYMBOL(comedi_buf_memcpy_to);
727
comedi_buf_memcpy_from(struct comedi_async * async,unsigned int offset,void * dest,unsigned int nbytes)728 void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset,
729 void *dest, unsigned int nbytes)
730 {
731 void *src;
732 unsigned int read_ptr = async->buf_read_ptr + offset;
733
734 if (read_ptr >= async->prealloc_bufsz)
735 read_ptr %= async->prealloc_bufsz;
736
737 while (nbytes) {
738 unsigned int block_size;
739
740 src = async->prealloc_buf + read_ptr;
741
742 if (nbytes >= async->prealloc_bufsz - read_ptr)
743 block_size = async->prealloc_bufsz - read_ptr;
744 else
745 block_size = nbytes;
746
747 memcpy(dest, src, block_size);
748 nbytes -= block_size;
749 dest += block_size;
750 read_ptr = 0;
751 }
752 }
753 EXPORT_SYMBOL(comedi_buf_memcpy_from);
754
comedi_buf_read_n_available(struct comedi_async * async)755 unsigned int comedi_buf_read_n_available(struct comedi_async *async)
756 {
757 unsigned num_bytes;
758
759 if (async == NULL)
760 return 0;
761 num_bytes = async->munge_count - async->buf_read_count;
762 /* barrier insures the read of munge_count in this
763 query occurs before any following reads of the buffer which
764 might be based on the return value from this query.
765 */
766 smp_rmb();
767 return num_bytes;
768 }
769 EXPORT_SYMBOL(comedi_buf_read_n_available);
770
comedi_buf_get(struct comedi_async * async,short * x)771 int comedi_buf_get(struct comedi_async *async, short *x)
772 {
773 unsigned int n = comedi_buf_read_n_available(async);
774
775 if (n < sizeof(short))
776 return 0;
777 comedi_buf_read_alloc(async, sizeof(short));
778 *x = *(short *)(async->prealloc_buf + async->buf_read_ptr);
779 comedi_buf_read_free(async, sizeof(short));
780 return 1;
781 }
782 EXPORT_SYMBOL(comedi_buf_get);
783
comedi_buf_put(struct comedi_async * async,short x)784 int comedi_buf_put(struct comedi_async *async, short x)
785 {
786 unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(short));
787
788 if (n < sizeof(short)) {
789 async->events |= COMEDI_CB_ERROR;
790 return 0;
791 }
792 *(short *)(async->prealloc_buf + async->buf_write_ptr) = x;
793 comedi_buf_write_free(async, sizeof(short));
794 return 1;
795 }
796 EXPORT_SYMBOL(comedi_buf_put);
797
comedi_reset_async_buf(struct comedi_async * async)798 void comedi_reset_async_buf(struct comedi_async *async)
799 {
800 async->buf_write_alloc_count = 0;
801 async->buf_write_count = 0;
802 async->buf_read_alloc_count = 0;
803 async->buf_read_count = 0;
804
805 async->buf_write_ptr = 0;
806 async->buf_read_ptr = 0;
807
808 async->cur_chan = 0;
809 async->scan_progress = 0;
810 async->munge_chan = 0;
811 async->munge_count = 0;
812 async->munge_ptr = 0;
813
814 async->events = 0;
815 }
816
comedi_auto_config(struct device * hardware_device,const char * board_name,const int * options,unsigned num_options)817 static int comedi_auto_config(struct device *hardware_device,
818 const char *board_name, const int *options,
819 unsigned num_options)
820 {
821 struct comedi_devconfig it;
822 int minor;
823 struct comedi_device_file_info *dev_file_info;
824 int retval;
825
826 if (!comedi_autoconfig)
827 return 0;
828
829 minor = comedi_alloc_board_minor(hardware_device);
830 if (minor < 0)
831 return minor;
832
833 dev_file_info = comedi_get_device_file_info(minor);
834
835 memset(&it, 0, sizeof(it));
836 strncpy(it.board_name, board_name, COMEDI_NAMELEN);
837 it.board_name[COMEDI_NAMELEN - 1] = '\0';
838 BUG_ON(num_options > COMEDI_NDEVCONFOPTS);
839 memcpy(it.options, options, num_options * sizeof(int));
840
841 mutex_lock(&dev_file_info->device->mutex);
842 retval = comedi_device_attach(dev_file_info->device, &it);
843 mutex_unlock(&dev_file_info->device->mutex);
844
845 if (retval < 0)
846 comedi_free_board_minor(minor);
847 return retval;
848 }
849
comedi_auto_unconfig(struct device * hardware_device)850 static void comedi_auto_unconfig(struct device *hardware_device)
851 {
852 int minor;
853
854 if (hardware_device == NULL)
855 return;
856 minor = comedi_find_board_minor(hardware_device);
857 if (minor < 0)
858 return;
859 BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
860 comedi_free_board_minor(minor);
861 }
862
comedi_pci_auto_config(struct pci_dev * pcidev,const char * board_name)863 int comedi_pci_auto_config(struct pci_dev *pcidev, const char *board_name)
864 {
865 int options[2];
866
867 /* pci bus */
868 options[0] = pcidev->bus->number;
869 /* pci slot */
870 options[1] = PCI_SLOT(pcidev->devfn);
871
872 return comedi_auto_config(&pcidev->dev, board_name,
873 options, ARRAY_SIZE(options));
874 }
875 EXPORT_SYMBOL_GPL(comedi_pci_auto_config);
876
comedi_pci_auto_unconfig(struct pci_dev * pcidev)877 void comedi_pci_auto_unconfig(struct pci_dev *pcidev)
878 {
879 comedi_auto_unconfig(&pcidev->dev);
880 }
881 EXPORT_SYMBOL_GPL(comedi_pci_auto_unconfig);
882
comedi_usb_auto_config(struct usb_device * usbdev,const char * board_name)883 int comedi_usb_auto_config(struct usb_device *usbdev, const char *board_name)
884 {
885 BUG_ON(usbdev == NULL);
886 return comedi_auto_config(&usbdev->dev, board_name, NULL, 0);
887 }
888 EXPORT_SYMBOL_GPL(comedi_usb_auto_config);
889
comedi_usb_auto_unconfig(struct usb_device * usbdev)890 void comedi_usb_auto_unconfig(struct usb_device *usbdev)
891 {
892 BUG_ON(usbdev == NULL);
893 comedi_auto_unconfig(&usbdev->dev);
894 }
895 EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig);
896