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 #include <asm/system.h>
46
47 #include "comedidev.h"
48 #include "internal.h"
49
50 static int postconfig(struct comedi_device *dev);
51 static int insn_rw_emulate_bits(struct comedi_device *dev,
52 struct comedi_subdevice *s,
53 struct comedi_insn *insn, unsigned int *data);
54 static void *comedi_recognize(struct comedi_driver *driv, const char *name);
55 static void comedi_report_boards(struct comedi_driver *driv);
56 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s);
57
58 struct comedi_driver *comedi_drivers;
59
cleanup_device(struct comedi_device * dev)60 static void cleanup_device(struct comedi_device *dev)
61 {
62 int i;
63 struct comedi_subdevice *s;
64
65 if (dev->subdevices) {
66 for (i = 0; i < dev->n_subdevices; i++) {
67 s = dev->subdevices + i;
68 comedi_free_subdevice_minor(s);
69 if (s->async) {
70 comedi_buf_alloc(dev, s, 0);
71 kfree(s->async);
72 }
73 }
74 kfree(dev->subdevices);
75 dev->subdevices = NULL;
76 dev->n_subdevices = 0;
77 }
78 kfree(dev->private);
79 dev->private = NULL;
80 dev->driver = NULL;
81 dev->board_name = NULL;
82 dev->board_ptr = NULL;
83 dev->iobase = 0;
84 dev->irq = 0;
85 dev->read_subdev = NULL;
86 dev->write_subdev = NULL;
87 dev->open = NULL;
88 dev->close = NULL;
89 comedi_set_hw_dev(dev, NULL);
90 }
91
__comedi_device_detach(struct comedi_device * dev)92 static void __comedi_device_detach(struct comedi_device *dev)
93 {
94 dev->attached = 0;
95 if (dev->driver)
96 dev->driver->detach(dev);
97 else
98 printk(KERN_WARNING
99 "BUG: dev->driver=NULL in comedi_device_detach()\n");
100 cleanup_device(dev);
101 }
102
comedi_device_detach(struct comedi_device * dev)103 void comedi_device_detach(struct comedi_device *dev)
104 {
105 if (!dev->attached)
106 return;
107 __comedi_device_detach(dev);
108 }
109
comedi_device_attach(struct comedi_device * dev,struct comedi_devconfig * it)110 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
111 {
112 struct comedi_driver *driv;
113 int ret;
114
115 if (dev->attached)
116 return -EBUSY;
117
118 for (driv = comedi_drivers; driv; driv = driv->next) {
119 if (!try_module_get(driv->module)) {
120 printk(KERN_INFO "comedi: failed to increment module count, skipping\n");
121 continue;
122 }
123 if (driv->num_names) {
124 dev->board_ptr = comedi_recognize(driv, it->board_name);
125 if (dev->board_ptr == NULL) {
126 module_put(driv->module);
127 continue;
128 }
129 } else {
130 if (strcmp(driv->driver_name, it->board_name)) {
131 module_put(driv->module);
132 continue;
133 }
134 }
135 /* initialize dev->driver here so
136 * comedi_error() can be called from attach */
137 dev->driver = driv;
138 ret = driv->attach(dev, it);
139 if (ret < 0) {
140 module_put(dev->driver->module);
141 __comedi_device_detach(dev);
142 return ret;
143 }
144 goto attached;
145 }
146
147 /* recognize has failed if we get here */
148 /* report valid board names before returning error */
149 for (driv = comedi_drivers; driv; driv = driv->next) {
150 if (!try_module_get(driv->module)) {
151 printk(KERN_INFO
152 "comedi: failed to increment module count\n");
153 continue;
154 }
155 comedi_report_boards(driv);
156 module_put(driv->module);
157 }
158 return -EIO;
159
160 attached:
161 /* do a little post-config cleanup */
162 ret = postconfig(dev);
163 module_put(dev->driver->module);
164 if (ret < 0) {
165 __comedi_device_detach(dev);
166 return ret;
167 }
168
169 if (!dev->board_name) {
170 printk(KERN_WARNING "BUG: dev->board_name=<%p>\n",
171 dev->board_name);
172 dev->board_name = "BUG";
173 }
174 smp_wmb();
175 dev->attached = 1;
176
177 return 0;
178 }
179
comedi_driver_register(struct comedi_driver * driver)180 int comedi_driver_register(struct comedi_driver *driver)
181 {
182 driver->next = comedi_drivers;
183 comedi_drivers = driver;
184
185 return 0;
186 }
187 EXPORT_SYMBOL(comedi_driver_register);
188
comedi_driver_unregister(struct comedi_driver * driver)189 int comedi_driver_unregister(struct comedi_driver *driver)
190 {
191 struct comedi_driver *prev;
192 int i;
193
194 /* check for devices using this driver */
195 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
196 struct comedi_device_file_info *dev_file_info =
197 comedi_get_device_file_info(i);
198 struct comedi_device *dev;
199
200 if (dev_file_info == NULL)
201 continue;
202 dev = dev_file_info->device;
203
204 mutex_lock(&dev->mutex);
205 if (dev->attached && dev->driver == driver) {
206 if (dev->use_count)
207 printk(KERN_WARNING "BUG! detaching device with use_count=%d\n",
208 dev->use_count);
209 comedi_device_detach(dev);
210 }
211 mutex_unlock(&dev->mutex);
212 }
213
214 if (comedi_drivers == driver) {
215 comedi_drivers = driver->next;
216 return 0;
217 }
218
219 for (prev = comedi_drivers; prev->next; prev = prev->next) {
220 if (prev->next == driver) {
221 prev->next = driver->next;
222 return 0;
223 }
224 }
225 return -EINVAL;
226 }
227 EXPORT_SYMBOL(comedi_driver_unregister);
228
postconfig(struct comedi_device * dev)229 static int postconfig(struct comedi_device *dev)
230 {
231 int i;
232 struct comedi_subdevice *s;
233 struct comedi_async *async = NULL;
234 int ret;
235
236 for (i = 0; i < dev->n_subdevices; i++) {
237 s = dev->subdevices + i;
238
239 if (s->type == COMEDI_SUBD_UNUSED)
240 continue;
241
242 if (s->len_chanlist == 0)
243 s->len_chanlist = 1;
244
245 if (s->do_cmd) {
246 BUG_ON((s->subdev_flags & (SDF_CMD_READ |
247 SDF_CMD_WRITE)) == 0);
248 BUG_ON(!s->do_cmdtest);
249
250 async =
251 kzalloc(sizeof(struct comedi_async), GFP_KERNEL);
252 if (async == NULL) {
253 printk(KERN_INFO
254 "failed to allocate async struct\n");
255 return -ENOMEM;
256 }
257 init_waitqueue_head(&async->wait_head);
258 async->subdevice = s;
259 s->async = async;
260
261 #define DEFAULT_BUF_MAXSIZE (64*1024)
262 #define DEFAULT_BUF_SIZE (64*1024)
263
264 async->max_bufsize = DEFAULT_BUF_MAXSIZE;
265
266 async->prealloc_buf = NULL;
267 async->prealloc_bufsz = 0;
268 if (comedi_buf_alloc(dev, s, DEFAULT_BUF_SIZE) < 0) {
269 printk(KERN_INFO "Buffer allocation failed\n");
270 return -ENOMEM;
271 }
272 if (s->buf_change) {
273 ret = s->buf_change(dev, s, DEFAULT_BUF_SIZE);
274 if (ret < 0)
275 return ret;
276 }
277 comedi_alloc_subdevice_minor(dev, s);
278 }
279
280 if (!s->range_table && !s->range_table_list)
281 s->range_table = &range_unknown;
282
283 if (!s->insn_read && s->insn_bits)
284 s->insn_read = insn_rw_emulate_bits;
285 if (!s->insn_write && s->insn_bits)
286 s->insn_write = insn_rw_emulate_bits;
287
288 if (!s->insn_read)
289 s->insn_read = insn_inval;
290 if (!s->insn_write)
291 s->insn_write = insn_inval;
292 if (!s->insn_bits)
293 s->insn_bits = insn_inval;
294 if (!s->insn_config)
295 s->insn_config = insn_inval;
296
297 if (!s->poll)
298 s->poll = poll_invalid;
299 }
300
301 return 0;
302 }
303
304 /* generic recognize function for drivers
305 * that register their supported board names */
comedi_recognize(struct comedi_driver * driv,const char * name)306 static void *comedi_recognize(struct comedi_driver *driv, const char *name)
307 {
308 unsigned i;
309 const char *const *name_ptr = driv->board_name;
310 for (i = 0; i < driv->num_names; i++) {
311 if (strcmp(*name_ptr, name) == 0)
312 return (void *)name_ptr;
313 name_ptr =
314 (const char *const *)((const char *)name_ptr +
315 driv->offset);
316 }
317
318 return NULL;
319 }
320
comedi_report_boards(struct comedi_driver * driv)321 static void comedi_report_boards(struct comedi_driver *driv)
322 {
323 unsigned int i;
324 const char *const *name_ptr;
325
326 printk(KERN_INFO "comedi: valid board names for %s driver are:\n",
327 driv->driver_name);
328
329 name_ptr = driv->board_name;
330 for (i = 0; i < driv->num_names; i++) {
331 printk(KERN_INFO " %s\n", *name_ptr);
332 name_ptr = (const char **)((char *)name_ptr + driv->offset);
333 }
334
335 if (driv->num_names == 0)
336 printk(KERN_INFO " %s\n", driv->driver_name);
337 }
338
poll_invalid(struct comedi_device * dev,struct comedi_subdevice * s)339 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
340 {
341 return -EINVAL;
342 }
343
insn_inval(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)344 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
345 struct comedi_insn *insn, unsigned int *data)
346 {
347 return -EINVAL;
348 }
349
insn_rw_emulate_bits(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)350 static int insn_rw_emulate_bits(struct comedi_device *dev,
351 struct comedi_subdevice *s,
352 struct comedi_insn *insn, unsigned int *data)
353 {
354 struct comedi_insn new_insn;
355 int ret;
356 static const unsigned channels_per_bitfield = 32;
357
358 unsigned chan = CR_CHAN(insn->chanspec);
359 const unsigned base_bitfield_channel =
360 (chan < channels_per_bitfield) ? 0 : chan;
361 unsigned int new_data[2];
362 memset(new_data, 0, sizeof(new_data));
363 memset(&new_insn, 0, sizeof(new_insn));
364 new_insn.insn = INSN_BITS;
365 new_insn.chanspec = base_bitfield_channel;
366 new_insn.n = 2;
367 new_insn.data = new_data;
368 new_insn.subdev = insn->subdev;
369
370 if (insn->insn == INSN_WRITE) {
371 if (!(s->subdev_flags & SDF_WRITABLE))
372 return -EINVAL;
373 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
374 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
375 : 0; /* bits */
376 }
377
378 ret = s->insn_bits(dev, s, &new_insn, new_data);
379 if (ret < 0)
380 return ret;
381
382 if (insn->insn == INSN_READ)
383 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
384
385 return 1;
386 }
387
uvirt_to_kva(pgd_t * pgd,unsigned long adr)388 static inline unsigned long uvirt_to_kva(pgd_t *pgd, unsigned long adr)
389 {
390 unsigned long ret = 0UL;
391 pmd_t *pmd;
392 pte_t *ptep, pte;
393 pud_t *pud;
394
395 if (!pgd_none(*pgd)) {
396 pud = pud_offset(pgd, adr);
397 pmd = pmd_offset(pud, adr);
398 if (!pmd_none(*pmd)) {
399 ptep = pte_offset_kernel(pmd, adr);
400 pte = *ptep;
401 if (pte_present(pte)) {
402 ret = (unsigned long)
403 page_address(pte_page(pte));
404 ret |= (adr & (PAGE_SIZE - 1));
405 }
406 }
407 }
408 return ret;
409 }
410
kvirt_to_kva(unsigned long adr)411 static inline unsigned long kvirt_to_kva(unsigned long adr)
412 {
413 unsigned long va, kva;
414
415 va = adr;
416 kva = uvirt_to_kva(pgd_offset_k(va), va);
417
418 return kva;
419 }
420
comedi_buf_alloc(struct comedi_device * dev,struct comedi_subdevice * s,unsigned long new_size)421 int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
422 unsigned long new_size)
423 {
424 struct comedi_async *async = s->async;
425
426 /* Round up new_size to multiple of PAGE_SIZE */
427 new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
428
429 /* if no change is required, do nothing */
430 if (async->prealloc_buf && async->prealloc_bufsz == new_size)
431 return 0;
432
433 /* deallocate old buffer */
434 if (async->prealloc_buf) {
435 vunmap(async->prealloc_buf);
436 async->prealloc_buf = NULL;
437 async->prealloc_bufsz = 0;
438 }
439 if (async->buf_page_list) {
440 unsigned i;
441 for (i = 0; i < async->n_buf_pages; ++i) {
442 if (async->buf_page_list[i].virt_addr) {
443 clear_bit(PG_reserved,
444 &(virt_to_page(async->buf_page_list[i].
445 virt_addr)->flags));
446 if (s->async_dma_dir != DMA_NONE) {
447 dma_free_coherent(dev->hw_dev,
448 PAGE_SIZE,
449 async->
450 buf_page_list
451 [i].virt_addr,
452 async->
453 buf_page_list
454 [i].dma_addr);
455 } else {
456 free_page((unsigned long)
457 async->buf_page_list[i].
458 virt_addr);
459 }
460 }
461 }
462 vfree(async->buf_page_list);
463 async->buf_page_list = NULL;
464 async->n_buf_pages = 0;
465 }
466 /* allocate new buffer */
467 if (new_size) {
468 unsigned i = 0;
469 unsigned n_pages = new_size >> PAGE_SHIFT;
470 struct page **pages = NULL;
471
472 async->buf_page_list =
473 vzalloc(sizeof(struct comedi_buf_page) * n_pages);
474 if (async->buf_page_list)
475 pages = vmalloc(sizeof(struct page *) * n_pages);
476
477 if (pages) {
478 for (i = 0; i < n_pages; i++) {
479 if (s->async_dma_dir != DMA_NONE) {
480 async->buf_page_list[i].virt_addr =
481 dma_alloc_coherent(dev->hw_dev,
482 PAGE_SIZE,
483 &async->
484 buf_page_list
485 [i].dma_addr,
486 GFP_KERNEL |
487 __GFP_COMP);
488 } else {
489 async->buf_page_list[i].virt_addr =
490 (void *)
491 get_zeroed_page(GFP_KERNEL);
492 }
493 if (async->buf_page_list[i].virt_addr == NULL)
494 break;
495
496 set_bit(PG_reserved,
497 &(virt_to_page(async->buf_page_list[i].
498 virt_addr)->flags));
499 pages[i] = virt_to_page(async->buf_page_list[i].
500 virt_addr);
501 }
502 }
503 if (i == n_pages) {
504 async->prealloc_buf =
505 #ifdef PAGE_KERNEL_NOCACHE
506 vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
507 #else
508 vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
509 #endif
510 }
511 vfree(pages);
512
513 if (async->prealloc_buf == NULL) {
514 /* Some allocation failed above. */
515 if (async->buf_page_list) {
516 for (i = 0; i < n_pages; i++) {
517 if (async->buf_page_list[i].virt_addr ==
518 NULL) {
519 break;
520 }
521 clear_bit(PG_reserved,
522 &(virt_to_page(async->
523 buf_page_list[i].
524 virt_addr)->flags));
525 if (s->async_dma_dir != DMA_NONE) {
526 dma_free_coherent(dev->hw_dev,
527 PAGE_SIZE,
528 async->
529 buf_page_list
530 [i].virt_addr,
531 async->
532 buf_page_list
533 [i].dma_addr);
534 } else {
535 free_page((unsigned long)
536 async->buf_page_list
537 [i].virt_addr);
538 }
539 }
540 vfree(async->buf_page_list);
541 async->buf_page_list = NULL;
542 }
543 return -ENOMEM;
544 }
545 async->n_buf_pages = n_pages;
546 }
547 async->prealloc_bufsz = new_size;
548
549 return 0;
550 }
551
552 /* munging is applied to data by core as it passes between user
553 * and kernel space */
comedi_buf_munge(struct comedi_async * async,unsigned int num_bytes)554 static unsigned int comedi_buf_munge(struct comedi_async *async,
555 unsigned int num_bytes)
556 {
557 struct comedi_subdevice *s = async->subdevice;
558 unsigned int count = 0;
559 const unsigned num_sample_bytes = bytes_per_sample(s);
560
561 if (s->munge == NULL || (async->cmd.flags & CMDF_RAWDATA)) {
562 async->munge_count += num_bytes;
563 BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
564 return num_bytes;
565 }
566 /* don't munge partial samples */
567 num_bytes -= num_bytes % num_sample_bytes;
568 while (count < num_bytes) {
569 int block_size;
570
571 block_size = num_bytes - count;
572 if (block_size < 0) {
573 printk(KERN_WARNING
574 "%s: %s: bug! block_size is negative\n",
575 __FILE__, __func__);
576 break;
577 }
578 if ((int)(async->munge_ptr + block_size -
579 async->prealloc_bufsz) > 0)
580 block_size = async->prealloc_bufsz - async->munge_ptr;
581
582 s->munge(s->device, s, async->prealloc_buf + async->munge_ptr,
583 block_size, async->munge_chan);
584
585 smp_wmb(); /* barrier insures data is munged in buffer
586 * before munge_count is incremented */
587
588 async->munge_chan += block_size / num_sample_bytes;
589 async->munge_chan %= async->cmd.chanlist_len;
590 async->munge_count += block_size;
591 async->munge_ptr += block_size;
592 async->munge_ptr %= async->prealloc_bufsz;
593 count += block_size;
594 }
595 BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
596 return count;
597 }
598
comedi_buf_write_n_available(struct comedi_async * async)599 unsigned int comedi_buf_write_n_available(struct comedi_async *async)
600 {
601 unsigned int free_end;
602 unsigned int nbytes;
603
604 if (async == NULL)
605 return 0;
606
607 free_end = async->buf_read_count + async->prealloc_bufsz;
608 nbytes = free_end - async->buf_write_alloc_count;
609 nbytes -= nbytes % bytes_per_sample(async->subdevice);
610 /* barrier insures the read of buf_read_count in this
611 query occurs before any following writes to the buffer which
612 might be based on the return value from this query.
613 */
614 smp_mb();
615 return nbytes;
616 }
617
618 /* allocates chunk for the writer from free buffer space */
comedi_buf_write_alloc(struct comedi_async * async,unsigned int nbytes)619 unsigned int comedi_buf_write_alloc(struct comedi_async *async,
620 unsigned int nbytes)
621 {
622 unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
623
624 if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
625 nbytes = free_end - async->buf_write_alloc_count;
626
627 async->buf_write_alloc_count += nbytes;
628 /* barrier insures the read of buf_read_count above occurs before
629 we write data to the write-alloc'ed buffer space */
630 smp_mb();
631 return nbytes;
632 }
633 EXPORT_SYMBOL(comedi_buf_write_alloc);
634
635 /* allocates nothing unless it can completely fulfill the request */
comedi_buf_write_alloc_strict(struct comedi_async * async,unsigned int nbytes)636 unsigned int comedi_buf_write_alloc_strict(struct comedi_async *async,
637 unsigned int nbytes)
638 {
639 unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
640
641 if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
642 nbytes = 0;
643
644 async->buf_write_alloc_count += nbytes;
645 /* barrier insures the read of buf_read_count above occurs before
646 we write data to the write-alloc'ed buffer space */
647 smp_mb();
648 return nbytes;
649 }
650
651 /* transfers a chunk from writer to filled buffer space */
comedi_buf_write_free(struct comedi_async * async,unsigned int nbytes)652 unsigned comedi_buf_write_free(struct comedi_async *async, unsigned int nbytes)
653 {
654 if ((int)(async->buf_write_count + nbytes -
655 async->buf_write_alloc_count) > 0) {
656 printk(KERN_INFO "comedi: attempted to write-free more bytes than have been write-allocated.\n");
657 nbytes = async->buf_write_alloc_count - async->buf_write_count;
658 }
659 async->buf_write_count += nbytes;
660 async->buf_write_ptr += nbytes;
661 comedi_buf_munge(async, async->buf_write_count - async->munge_count);
662 if (async->buf_write_ptr >= async->prealloc_bufsz)
663 async->buf_write_ptr %= async->prealloc_bufsz;
664
665 return nbytes;
666 }
667 EXPORT_SYMBOL(comedi_buf_write_free);
668
669 /* allocates a chunk for the reader from filled (and munged) buffer space */
comedi_buf_read_alloc(struct comedi_async * async,unsigned nbytes)670 unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes)
671 {
672 if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) >
673 0) {
674 nbytes = async->munge_count - async->buf_read_alloc_count;
675 }
676 async->buf_read_alloc_count += nbytes;
677 /* barrier insures read of munge_count occurs before we actually read
678 data out of buffer */
679 smp_rmb();
680 return nbytes;
681 }
682 EXPORT_SYMBOL(comedi_buf_read_alloc);
683
684 /* transfers control of a chunk from reader to free buffer space */
comedi_buf_read_free(struct comedi_async * async,unsigned int nbytes)685 unsigned comedi_buf_read_free(struct comedi_async *async, unsigned int nbytes)
686 {
687 /* barrier insures data has been read out of
688 * buffer before read count is incremented */
689 smp_mb();
690 if ((int)(async->buf_read_count + nbytes -
691 async->buf_read_alloc_count) > 0) {
692 printk(KERN_INFO
693 "comedi: attempted to read-free more bytes than have been read-allocated.\n");
694 nbytes = async->buf_read_alloc_count - async->buf_read_count;
695 }
696 async->buf_read_count += nbytes;
697 async->buf_read_ptr += nbytes;
698 async->buf_read_ptr %= async->prealloc_bufsz;
699 return nbytes;
700 }
701 EXPORT_SYMBOL(comedi_buf_read_free);
702
comedi_buf_memcpy_to(struct comedi_async * async,unsigned int offset,const void * data,unsigned int num_bytes)703 void comedi_buf_memcpy_to(struct comedi_async *async, unsigned int offset,
704 const void *data, unsigned int num_bytes)
705 {
706 unsigned int write_ptr = async->buf_write_ptr + offset;
707
708 if (write_ptr >= async->prealloc_bufsz)
709 write_ptr %= async->prealloc_bufsz;
710
711 while (num_bytes) {
712 unsigned int block_size;
713
714 if (write_ptr + num_bytes > async->prealloc_bufsz)
715 block_size = async->prealloc_bufsz - write_ptr;
716 else
717 block_size = num_bytes;
718
719 memcpy(async->prealloc_buf + write_ptr, data, block_size);
720
721 data += block_size;
722 num_bytes -= block_size;
723
724 write_ptr = 0;
725 }
726 }
727 EXPORT_SYMBOL(comedi_buf_memcpy_to);
728
comedi_buf_memcpy_from(struct comedi_async * async,unsigned int offset,void * dest,unsigned int nbytes)729 void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset,
730 void *dest, unsigned int nbytes)
731 {
732 void *src;
733 unsigned int read_ptr = async->buf_read_ptr + offset;
734
735 if (read_ptr >= async->prealloc_bufsz)
736 read_ptr %= async->prealloc_bufsz;
737
738 while (nbytes) {
739 unsigned int block_size;
740
741 src = async->prealloc_buf + read_ptr;
742
743 if (nbytes >= async->prealloc_bufsz - read_ptr)
744 block_size = async->prealloc_bufsz - read_ptr;
745 else
746 block_size = nbytes;
747
748 memcpy(dest, src, block_size);
749 nbytes -= block_size;
750 dest += block_size;
751 read_ptr = 0;
752 }
753 }
754 EXPORT_SYMBOL(comedi_buf_memcpy_from);
755
comedi_buf_read_n_available(struct comedi_async * async)756 unsigned int comedi_buf_read_n_available(struct comedi_async *async)
757 {
758 unsigned num_bytes;
759
760 if (async == NULL)
761 return 0;
762 num_bytes = async->munge_count - async->buf_read_count;
763 /* barrier insures the read of munge_count in this
764 query occurs before any following reads of the buffer which
765 might be based on the return value from this query.
766 */
767 smp_rmb();
768 return num_bytes;
769 }
770 EXPORT_SYMBOL(comedi_buf_read_n_available);
771
comedi_buf_get(struct comedi_async * async,short * x)772 int comedi_buf_get(struct comedi_async *async, short *x)
773 {
774 unsigned int n = comedi_buf_read_n_available(async);
775
776 if (n < sizeof(short))
777 return 0;
778 comedi_buf_read_alloc(async, sizeof(short));
779 *x = *(short *)(async->prealloc_buf + async->buf_read_ptr);
780 comedi_buf_read_free(async, sizeof(short));
781 return 1;
782 }
783 EXPORT_SYMBOL(comedi_buf_get);
784
comedi_buf_put(struct comedi_async * async,short x)785 int comedi_buf_put(struct comedi_async *async, short x)
786 {
787 unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(short));
788
789 if (n < sizeof(short)) {
790 async->events |= COMEDI_CB_ERROR;
791 return 0;
792 }
793 *(short *)(async->prealloc_buf + async->buf_write_ptr) = x;
794 comedi_buf_write_free(async, sizeof(short));
795 return 1;
796 }
797 EXPORT_SYMBOL(comedi_buf_put);
798
comedi_reset_async_buf(struct comedi_async * async)799 void comedi_reset_async_buf(struct comedi_async *async)
800 {
801 async->buf_write_alloc_count = 0;
802 async->buf_write_count = 0;
803 async->buf_read_alloc_count = 0;
804 async->buf_read_count = 0;
805
806 async->buf_write_ptr = 0;
807 async->buf_read_ptr = 0;
808
809 async->cur_chan = 0;
810 async->scan_progress = 0;
811 async->munge_chan = 0;
812 async->munge_count = 0;
813 async->munge_ptr = 0;
814
815 async->events = 0;
816 }
817
comedi_auto_config(struct device * hardware_device,const char * board_name,const int * options,unsigned num_options)818 static int comedi_auto_config(struct device *hardware_device,
819 const char *board_name, const int *options,
820 unsigned num_options)
821 {
822 struct comedi_devconfig it;
823 int minor;
824 struct comedi_device_file_info *dev_file_info;
825 int retval;
826 unsigned *private_data = NULL;
827
828 if (!comedi_autoconfig) {
829 dev_set_drvdata(hardware_device, NULL);
830 return 0;
831 }
832
833 minor = comedi_alloc_board_minor(hardware_device);
834 if (minor < 0)
835 return minor;
836
837 private_data = kmalloc(sizeof(unsigned), GFP_KERNEL);
838 if (private_data == NULL) {
839 retval = -ENOMEM;
840 goto cleanup;
841 }
842 *private_data = minor;
843 dev_set_drvdata(hardware_device, private_data);
844
845 dev_file_info = comedi_get_device_file_info(minor);
846
847 memset(&it, 0, sizeof(it));
848 strncpy(it.board_name, board_name, COMEDI_NAMELEN);
849 it.board_name[COMEDI_NAMELEN - 1] = '\0';
850 BUG_ON(num_options > COMEDI_NDEVCONFOPTS);
851 memcpy(it.options, options, num_options * sizeof(int));
852
853 mutex_lock(&dev_file_info->device->mutex);
854 retval = comedi_device_attach(dev_file_info->device, &it);
855 mutex_unlock(&dev_file_info->device->mutex);
856
857 cleanup:
858 if (retval < 0) {
859 kfree(private_data);
860 comedi_free_board_minor(minor);
861 }
862 return retval;
863 }
864
comedi_auto_unconfig(struct device * hardware_device)865 static void comedi_auto_unconfig(struct device *hardware_device)
866 {
867 unsigned *minor = (unsigned *)dev_get_drvdata(hardware_device);
868 if (minor == NULL)
869 return;
870
871 BUG_ON(*minor >= COMEDI_NUM_BOARD_MINORS);
872
873 comedi_free_board_minor(*minor);
874 dev_set_drvdata(hardware_device, NULL);
875 kfree(minor);
876 }
877
comedi_pci_auto_config(struct pci_dev * pcidev,const char * board_name)878 int comedi_pci_auto_config(struct pci_dev *pcidev, const char *board_name)
879 {
880 int options[2];
881
882 /* pci bus */
883 options[0] = pcidev->bus->number;
884 /* pci slot */
885 options[1] = PCI_SLOT(pcidev->devfn);
886
887 return comedi_auto_config(&pcidev->dev, board_name,
888 options, ARRAY_SIZE(options));
889 }
890 EXPORT_SYMBOL_GPL(comedi_pci_auto_config);
891
comedi_pci_auto_unconfig(struct pci_dev * pcidev)892 void comedi_pci_auto_unconfig(struct pci_dev *pcidev)
893 {
894 comedi_auto_unconfig(&pcidev->dev);
895 }
896 EXPORT_SYMBOL_GPL(comedi_pci_auto_unconfig);
897
comedi_usb_auto_config(struct usb_device * usbdev,const char * board_name)898 int comedi_usb_auto_config(struct usb_device *usbdev, const char *board_name)
899 {
900 BUG_ON(usbdev == NULL);
901 return comedi_auto_config(&usbdev->dev, board_name, NULL, 0);
902 }
903 EXPORT_SYMBOL_GPL(comedi_usb_auto_config);
904
comedi_usb_auto_unconfig(struct usb_device * usbdev)905 void comedi_usb_auto_unconfig(struct usb_device *usbdev)
906 {
907 BUG_ON(usbdev == NULL);
908 comedi_auto_unconfig(&usbdev->dev);
909 }
910 EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig);
911