drivers.c revision be29eac8ed3fd21d86f79d2e84dff49b8a13cd2c
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 "comedidev.h" 41#include <linux/highmem.h> /* for SuSE brokenness */ 42#include <linux/vmalloc.h> 43#include <linux/cdev.h> 44#include <linux/dma-mapping.h> 45 46#include <linux/io.h> 47#include <asm/system.h> 48 49static int postconfig(struct comedi_device *dev); 50static int insn_rw_emulate_bits(struct comedi_device *dev, 51 struct comedi_subdevice *s, 52 struct comedi_insn *insn, unsigned int *data); 53static void *comedi_recognize(struct comedi_driver *driv, const char *name); 54static void comedi_report_boards(struct comedi_driver *driv); 55static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s); 56int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, 57 unsigned long new_size); 58 59struct comedi_driver *comedi_drivers; 60 61int comedi_modprobe(int minor) 62{ 63 return -EINVAL; 64} 65 66static void cleanup_device(struct comedi_device *dev) 67{ 68 int i; 69 struct comedi_subdevice *s; 70 71 if (dev->subdevices) { 72 for (i = 0; i < dev->n_subdevices; i++) { 73 s = dev->subdevices + i; 74 comedi_free_subdevice_minor(s); 75 if (s->async) { 76 comedi_buf_alloc(dev, s, 0); 77 kfree(s->async); 78 } 79 } 80 kfree(dev->subdevices); 81 dev->subdevices = NULL; 82 dev->n_subdevices = 0; 83 } 84 kfree(dev->private); 85 dev->private = NULL; 86 dev->driver = 0; 87 dev->board_name = NULL; 88 dev->board_ptr = NULL; 89 dev->iobase = 0; 90 dev->irq = 0; 91 dev->read_subdev = NULL; 92 dev->write_subdev = NULL; 93 dev->open = NULL; 94 dev->close = NULL; 95 comedi_set_hw_dev(dev, NULL); 96} 97 98static void __comedi_device_detach(struct comedi_device *dev) 99{ 100 dev->attached = 0; 101 if (dev->driver) 102 dev->driver->detach(dev); 103 else 104 printk(KERN_WARNING "BUG: dev->driver=NULL in comedi_device_detach()\n"); 105 cleanup_device(dev); 106} 107 108void comedi_device_detach(struct comedi_device *dev) 109{ 110 if (!dev->attached) 111 return; 112 __comedi_device_detach(dev); 113} 114 115int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) 116{ 117 struct comedi_driver *driv; 118 int ret; 119 120 if (dev->attached) 121 return -EBUSY; 122 123 for (driv = comedi_drivers; driv; driv = driv->next) { 124 if (!try_module_get(driv->module)) { 125 printk 126 (KERN_INFO "comedi: failed to increment module count, skipping\n"); 127 continue; 128 } 129 if (driv->num_names) { 130 dev->board_ptr = comedi_recognize(driv, it->board_name); 131 if (dev->board_ptr == NULL) { 132 module_put(driv->module); 133 continue; 134 } 135 } else { 136 if (strcmp(driv->driver_name, it->board_name)) { 137 module_put(driv->module); 138 continue; 139 } 140 } 141 /* initialize dev->driver here so 142 * comedi_error() can be called from attach */ 143 dev->driver = driv; 144 ret = driv->attach(dev, it); 145 if (ret < 0) { 146 module_put(dev->driver->module); 147 __comedi_device_detach(dev); 148 return ret; 149 } 150 goto attached; 151 } 152 153 /* recognize has failed if we get here */ 154 /* report valid board names before returning error */ 155 for (driv = comedi_drivers; driv; driv = driv->next) { 156 if (!try_module_get(driv->module)) { 157 printk(KERN_INFO "comedi: failed to increment module count\n"); 158 continue; 159 } 160 comedi_report_boards(driv); 161 module_put(driv->module); 162 } 163 return -EIO; 164 165attached: 166 /* do a little post-config cleanup */ 167 ret = postconfig(dev); 168 module_put(dev->driver->module); 169 if (ret < 0) { 170 __comedi_device_detach(dev); 171 return ret; 172 } 173 174 if (!dev->board_name) { 175 printk(KERN_WARNING "BUG: dev->board_name=<%p>\n", dev->board_name); 176 dev->board_name = "BUG"; 177 } 178 smp_wmb(); 179 dev->attached = 1; 180 181 return 0; 182} 183 184int comedi_driver_register(struct comedi_driver *driver) 185{ 186 driver->next = comedi_drivers; 187 comedi_drivers = driver; 188 189 return 0; 190} 191 192int comedi_driver_unregister(struct comedi_driver *driver) 193{ 194 struct comedi_driver *prev; 195 int i; 196 197 /* check for devices using this driver */ 198 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { 199 struct comedi_device_file_info *dev_file_info = 200 comedi_get_device_file_info(i); 201 struct comedi_device *dev; 202 203 if (dev_file_info == NULL) 204 continue; 205 dev = dev_file_info->device; 206 207 mutex_lock(&dev->mutex); 208 if (dev->attached && dev->driver == driver) { 209 if (dev->use_count) 210 printk 211 (KERN_WARNING "BUG! detaching device with use_count=%d\n", 212 dev->use_count); 213 comedi_device_detach(dev); 214 } 215 mutex_unlock(&dev->mutex); 216 } 217 218 if (comedi_drivers == driver) { 219 comedi_drivers = driver->next; 220 return 0; 221 } 222 223 for (prev = comedi_drivers; prev->next; prev = prev->next) { 224 if (prev->next == driver) { 225 prev->next = driver->next; 226 return 0; 227 } 228 } 229 return -EINVAL; 230} 231 232static int postconfig(struct comedi_device *dev) 233{ 234 int i; 235 struct comedi_subdevice *s; 236 struct comedi_async *async = NULL; 237 int ret; 238 239 for (i = 0; i < dev->n_subdevices; i++) { 240 s = dev->subdevices + i; 241 242 if (s->type == COMEDI_SUBD_UNUSED) 243 continue; 244 245 if (s->len_chanlist == 0) 246 s->len_chanlist = 1; 247 248 if (s->do_cmd) { 249 BUG_ON((s->subdev_flags & (SDF_CMD_READ | 250 SDF_CMD_WRITE)) == 0); 251 BUG_ON(!s->do_cmdtest); 252 253 async = 254 kzalloc(sizeof(struct comedi_async), GFP_KERNEL); 255 if (async == NULL) { 256 printk(KERN_INFO "failed to allocate async struct\n"); 257 return -ENOMEM; 258 } 259 init_waitqueue_head(&async->wait_head); 260 async->subdevice = s; 261 s->async = async; 262 263#define DEFAULT_BUF_MAXSIZE (64*1024) 264#define DEFAULT_BUF_SIZE (64*1024) 265 266 async->max_bufsize = DEFAULT_BUF_MAXSIZE; 267 268 async->prealloc_buf = NULL; 269 async->prealloc_bufsz = 0; 270 if (comedi_buf_alloc(dev, s, DEFAULT_BUF_SIZE) < 0) { 271 printk(KERN_INFO "Buffer allocation failed\n"); 272 return -ENOMEM; 273 } 274 if (s->buf_change) { 275 ret = s->buf_change(dev, s, DEFAULT_BUF_SIZE); 276 if (ret < 0) 277 return ret; 278 } 279 comedi_alloc_subdevice_minor(dev, s); 280 } 281 282 if (!s->range_table && !s->range_table_list) 283 s->range_table = &range_unknown; 284 285 if (!s->insn_read && s->insn_bits) 286 s->insn_read = insn_rw_emulate_bits; 287 if (!s->insn_write && s->insn_bits) 288 s->insn_write = insn_rw_emulate_bits; 289 290 if (!s->insn_read) 291 s->insn_read = insn_inval; 292 if (!s->insn_write) 293 s->insn_write = insn_inval; 294 if (!s->insn_bits) 295 s->insn_bits = insn_inval; 296 if (!s->insn_config) 297 s->insn_config = insn_inval; 298 299 if (!s->poll) 300 s->poll = poll_invalid; 301 } 302 303 return 0; 304} 305 306/* generic recognize function for drivers 307 * that register their supported board names */ 308void *comedi_recognize(struct comedi_driver *driv, const char *name) 309{ 310 unsigned i; 311 const char *const *name_ptr = driv->board_name; 312 for (i = 0; i < driv->num_names; i++) { 313 if (strcmp(*name_ptr, name) == 0) 314 return (void *)name_ptr; 315 name_ptr = 316 (const char *const *)((const char *)name_ptr + 317 driv->offset); 318 } 319 320 return NULL; 321} 322 323void comedi_report_boards(struct comedi_driver *driv) 324{ 325 unsigned int i; 326 const char *const *name_ptr; 327 328 printk(KERN_INFO "comedi: valid board names for %s driver are:\n", 329 driv->driver_name); 330 331 name_ptr = driv->board_name; 332 for (i = 0; i < driv->num_names; i++) { 333 printk(KERN_INFO " %s\n", *name_ptr); 334 name_ptr = (const char **)((char *)name_ptr + driv->offset); 335 } 336 337 if (driv->num_names == 0) 338 printk(KERN_INFO " %s\n", driv->driver_name); 339} 340 341static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) 342{ 343 return -EINVAL; 344} 345 346int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, 347 struct comedi_insn *insn, unsigned int *data) 348{ 349 return -EINVAL; 350} 351 352static int insn_rw_emulate_bits(struct comedi_device *dev, 353 struct comedi_subdevice *s, 354 struct comedi_insn *insn, unsigned int *data) 355{ 356 struct comedi_insn new_insn; 357 int ret; 358 static const unsigned channels_per_bitfield = 32; 359 360 unsigned chan = CR_CHAN(insn->chanspec); 361 const unsigned base_bitfield_channel = 362 (chan < channels_per_bitfield) ? 0 : chan; 363 unsigned int new_data[2]; 364 memset(new_data, 0, sizeof(new_data)); 365 memset(&new_insn, 0, sizeof(new_insn)); 366 new_insn.insn = INSN_BITS; 367 new_insn.chanspec = base_bitfield_channel; 368 new_insn.n = 2; 369 new_insn.data = new_data; 370 new_insn.subdev = insn->subdev; 371 372 if (insn->insn == INSN_WRITE) { 373 if (!(s->subdev_flags & SDF_WRITABLE)) 374 return -EINVAL; 375 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */ 376 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel)) : 0; /* bits */ 377 } 378 379 ret = s->insn_bits(dev, s, &new_insn, new_data); 380 if (ret < 0) 381 return ret; 382 383 if (insn->insn == INSN_READ) 384 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1; 385 386 return 1; 387} 388 389static inline unsigned long uvirt_to_kva(pgd_t *pgd, unsigned long adr) 390{ 391 unsigned long ret = 0UL; 392 pmd_t *pmd; 393 pte_t *ptep, pte; 394 pud_t *pud; 395 396 if (!pgd_none(*pgd)) { 397 pud = pud_offset(pgd, adr); 398 pmd = pmd_offset(pud, adr); 399 if (!pmd_none(*pmd)) { 400 ptep = pte_offset_kernel(pmd, adr); 401 pte = *ptep; 402 if (pte_present(pte)) { 403 ret = (unsigned long) 404 page_address(pte_page(pte)); 405 ret |= (adr & (PAGE_SIZE - 1)); 406 } 407 } 408 } 409 return ret; 410} 411 412static inline unsigned long kvirt_to_kva(unsigned long adr) 413{ 414 unsigned long va, kva; 415 416 va = adr; 417 kva = uvirt_to_kva(pgd_offset_k(va), va); 418 419 return kva; 420} 421 422int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, 423 unsigned long new_size) 424{ 425 struct comedi_async *async = s->async; 426 427 /* Round up new_size to multiple of PAGE_SIZE */ 428 new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK; 429 430 /* if no change is required, do nothing */ 431 if (async->prealloc_buf && async->prealloc_bufsz == new_size) 432 return 0; 433 434 /* deallocate old buffer */ 435 if (async->prealloc_buf) { 436 vunmap(async->prealloc_buf); 437 async->prealloc_buf = NULL; 438 async->prealloc_bufsz = 0; 439 } 440 if (async->buf_page_list) { 441 unsigned i; 442 for (i = 0; i < async->n_buf_pages; ++i) { 443 if (async->buf_page_list[i].virt_addr) { 444 clear_bit(PG_reserved, &(virt_to_page(async->buf_page_list[i].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 vmalloc(sizeof(struct comedi_buf_page) * n_pages); 473 if (async->buf_page_list) { 474 memset(async->buf_page_list, 0, 475 sizeof(struct comedi_buf_page) * n_pages); 476 pages = vmalloc(sizeof(struct page *) * n_pages); 477 } 478 if (pages) { 479 for (i = 0; i < n_pages; i++) { 480 if (s->async_dma_dir != DMA_NONE) { 481 async->buf_page_list[i].virt_addr = 482 dma_alloc_coherent(dev->hw_dev, 483 PAGE_SIZE, 484 &async-> 485 buf_page_list 486 [i].dma_addr, 487 GFP_KERNEL | 488 __GFP_COMP); 489 } else { 490 async->buf_page_list[i].virt_addr = 491 (void *) 492 get_zeroed_page(GFP_KERNEL); 493 } 494 if (async->buf_page_list[i].virt_addr == NULL) 495 break; 496 497 set_bit(PG_reserved, 498 &(virt_to_page(async->buf_page_list[i].virt_addr)->flags)); 499 pages[i] = virt_to_page(async->buf_page_list[i].virt_addr); 500 } 501 } 502 if (i == n_pages) { 503 async->prealloc_buf = 504 vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE); 505 } 506 vfree(pages); 507 508 if (async->prealloc_buf == NULL) { 509 /* Some allocation failed above. */ 510 if (async->buf_page_list) { 511 for (i = 0; i < n_pages; i++) { 512 if (async->buf_page_list[i].virt_addr == 513 NULL) { 514 break; 515 } 516 clear_bit(PG_reserved, &(virt_to_page(async->buf_page_list[i].virt_addr)->flags)); 517 if (s->async_dma_dir != DMA_NONE) { 518 dma_free_coherent(dev->hw_dev, 519 PAGE_SIZE, 520 async-> 521 buf_page_list 522 [i].virt_addr, 523 async-> 524 buf_page_list 525 [i].dma_addr); 526 } else { 527 free_page((unsigned long) 528 async->buf_page_list 529 [i].virt_addr); 530 } 531 } 532 vfree(async->buf_page_list); 533 async->buf_page_list = NULL; 534 } 535 return -ENOMEM; 536 } 537 async->n_buf_pages = n_pages; 538 } 539 async->prealloc_bufsz = new_size; 540 541 return 0; 542} 543 544/* munging is applied to data by core as it passes between user 545 * and kernel space */ 546unsigned int comedi_buf_munge(struct comedi_async *async, 547 unsigned int num_bytes) 548{ 549 struct comedi_subdevice *s = async->subdevice; 550 unsigned int count = 0; 551 const unsigned num_sample_bytes = bytes_per_sample(s); 552 553 if (s->munge == NULL || (async->cmd.flags & CMDF_RAWDATA)) { 554 async->munge_count += num_bytes; 555 BUG_ON((int)(async->munge_count - async->buf_write_count) > 0); 556 return num_bytes; 557 } 558 /* don't munge partial samples */ 559 num_bytes -= num_bytes % num_sample_bytes; 560 while (count < num_bytes) { 561 int block_size; 562 563 block_size = num_bytes - count; 564 if (block_size < 0) { 565 printk(KERN_WARNING "%s: %s: bug! block_size is negative\n", 566 __FILE__, __func__); 567 break; 568 } 569 if ((int)(async->munge_ptr + block_size - 570 async->prealloc_bufsz) > 0) 571 block_size = async->prealloc_bufsz - async->munge_ptr; 572 573 s->munge(s->device, s, async->prealloc_buf + async->munge_ptr, 574 block_size, async->munge_chan); 575 576 smp_wmb(); /* barrier insures data is munged in buffer 577 * before munge_count is incremented */ 578 579 async->munge_chan += block_size / num_sample_bytes; 580 async->munge_chan %= async->cmd.chanlist_len; 581 async->munge_count += block_size; 582 async->munge_ptr += block_size; 583 async->munge_ptr %= async->prealloc_bufsz; 584 count += block_size; 585 } 586 BUG_ON((int)(async->munge_count - async->buf_write_count) > 0); 587 return count; 588} 589 590unsigned int comedi_buf_write_n_available(struct comedi_async *async) 591{ 592 unsigned int free_end; 593 unsigned int nbytes; 594 595 if (async == NULL) 596 return 0; 597 598 free_end = async->buf_read_count + async->prealloc_bufsz; 599 nbytes = free_end - async->buf_write_alloc_count; 600 nbytes -= nbytes % bytes_per_sample(async->subdevice); 601 /* barrier insures the read of buf_read_count in this 602 query occurs before any following writes to the buffer which 603 might be based on the return value from this query. 604 */ 605 smp_mb(); 606 return nbytes; 607} 608 609/* allocates chunk for the writer from free buffer space */ 610unsigned int comedi_buf_write_alloc(struct comedi_async *async, 611 unsigned int nbytes) 612{ 613 unsigned int free_end = async->buf_read_count + async->prealloc_bufsz; 614 615 if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0) 616 nbytes = free_end - async->buf_write_alloc_count; 617 618 async->buf_write_alloc_count += nbytes; 619 /* barrier insures the read of buf_read_count above occurs before 620 we write data to the write-alloc'ed buffer space */ 621 smp_mb(); 622 return nbytes; 623} 624 625/* allocates nothing unless it can completely fulfill the request */ 626unsigned int comedi_buf_write_alloc_strict(struct comedi_async *async, 627 unsigned int nbytes) 628{ 629 unsigned int free_end = async->buf_read_count + async->prealloc_bufsz; 630 631 if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0) 632 nbytes = 0; 633 634 async->buf_write_alloc_count += nbytes; 635 /* barrier insures the read of buf_read_count above occurs before 636 we write data to the write-alloc'ed buffer space */ 637 smp_mb(); 638 return nbytes; 639} 640 641/* transfers a chunk from writer to filled buffer space */ 642unsigned comedi_buf_write_free(struct comedi_async *async, unsigned int nbytes) 643{ 644 if ((int)(async->buf_write_count + nbytes - 645 async->buf_write_alloc_count) > 0) { 646 printk 647 (KERN_INFO "comedi: attempted to write-free more bytes than have been write-allocated.\n"); 648 nbytes = async->buf_write_alloc_count - async->buf_write_count; 649 } 650 async->buf_write_count += nbytes; 651 async->buf_write_ptr += nbytes; 652 comedi_buf_munge(async, async->buf_write_count - async->munge_count); 653 if (async->buf_write_ptr >= async->prealloc_bufsz) 654 async->buf_write_ptr %= async->prealloc_bufsz; 655 656 return nbytes; 657} 658 659/* allocates a chunk for the reader from filled (and munged) buffer space */ 660unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes) 661{ 662 if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) > 663 0) { 664 nbytes = async->munge_count - async->buf_read_alloc_count; 665 } 666 async->buf_read_alloc_count += nbytes; 667 /* barrier insures read of munge_count occurs before we actually read 668 data out of buffer */ 669 smp_rmb(); 670 return nbytes; 671} 672 673/* transfers control of a chunk from reader to free buffer space */ 674unsigned comedi_buf_read_free(struct comedi_async *async, unsigned int nbytes) 675{ 676 /* barrier insures data has been read out of 677 * buffer before read count is incremented */ 678 smp_mb(); 679 if ((int)(async->buf_read_count + nbytes - 680 async->buf_read_alloc_count) > 0) { 681 printk 682 ("comedi: attempted to read-free more bytes than have been read-allocated.\n"); 683 nbytes = async->buf_read_alloc_count - async->buf_read_count; 684 } 685 async->buf_read_count += nbytes; 686 async->buf_read_ptr += nbytes; 687 async->buf_read_ptr %= async->prealloc_bufsz; 688 return nbytes; 689} 690 691void comedi_buf_memcpy_to(struct comedi_async *async, unsigned int offset, 692 const void *data, unsigned int num_bytes) 693{ 694 unsigned int write_ptr = async->buf_write_ptr + offset; 695 696 if (write_ptr >= async->prealloc_bufsz) 697 write_ptr %= async->prealloc_bufsz; 698 699 while (num_bytes) { 700 unsigned int block_size; 701 702 if (write_ptr + num_bytes > async->prealloc_bufsz) 703 block_size = async->prealloc_bufsz - write_ptr; 704 else 705 block_size = num_bytes; 706 707 memcpy(async->prealloc_buf + write_ptr, data, block_size); 708 709 data += block_size; 710 num_bytes -= block_size; 711 712 write_ptr = 0; 713 } 714} 715 716void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset, 717 void *dest, unsigned int nbytes) 718{ 719 void *src; 720 unsigned int read_ptr = async->buf_read_ptr + offset; 721 722 if (read_ptr >= async->prealloc_bufsz) 723 read_ptr %= async->prealloc_bufsz; 724 725 while (nbytes) { 726 unsigned int block_size; 727 728 src = async->prealloc_buf + read_ptr; 729 730 if (nbytes >= async->prealloc_bufsz - read_ptr) 731 block_size = async->prealloc_bufsz - read_ptr; 732 else 733 block_size = nbytes; 734 735 memcpy(dest, src, block_size); 736 nbytes -= block_size; 737 dest += block_size; 738 read_ptr = 0; 739 } 740} 741 742unsigned int comedi_buf_read_n_available(struct comedi_async *async) 743{ 744 unsigned num_bytes; 745 746 if (async == NULL) 747 return 0; 748 num_bytes = async->munge_count - async->buf_read_count; 749 /* barrier insures the read of munge_count in this 750 query occurs before any following reads of the buffer which 751 might be based on the return value from this query. 752 */ 753 smp_rmb(); 754 return num_bytes; 755} 756 757int comedi_buf_get(struct comedi_async *async, short *x) 758{ 759 unsigned int n = comedi_buf_read_n_available(async); 760 761 if (n < sizeof(short)) 762 return 0; 763 comedi_buf_read_alloc(async, sizeof(short)); 764 *x = *(short *)(async->prealloc_buf + async->buf_read_ptr); 765 comedi_buf_read_free(async, sizeof(short)); 766 return 1; 767} 768 769int comedi_buf_put(struct comedi_async *async, short x) 770{ 771 unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(short)); 772 773 if (n < sizeof(short)) { 774 async->events |= COMEDI_CB_ERROR; 775 return 0; 776 } 777 *(short *)(async->prealloc_buf + async->buf_write_ptr) = x; 778 comedi_buf_write_free(async, sizeof(short)); 779 return 1; 780} 781 782void comedi_reset_async_buf(struct comedi_async *async) 783{ 784 async->buf_write_alloc_count = 0; 785 async->buf_write_count = 0; 786 async->buf_read_alloc_count = 0; 787 async->buf_read_count = 0; 788 789 async->buf_write_ptr = 0; 790 async->buf_read_ptr = 0; 791 792 async->cur_chan = 0; 793 async->scan_progress = 0; 794 async->munge_chan = 0; 795 async->munge_count = 0; 796 async->munge_ptr = 0; 797 798 async->events = 0; 799} 800 801int comedi_auto_config(struct device *hardware_device, const char *board_name, 802 const int *options, unsigned num_options) 803{ 804 struct comedi_devconfig it; 805 int minor; 806 struct comedi_device_file_info *dev_file_info; 807 int retval; 808 unsigned *private_data = NULL; 809 810 if (!comedi_autoconfig) { 811 dev_set_drvdata(hardware_device, NULL); 812 return 0; 813 } 814 815 minor = comedi_alloc_board_minor(hardware_device); 816 if (minor < 0) 817 return minor; 818 819 private_data = kmalloc(sizeof(unsigned), GFP_KERNEL); 820 if (private_data == NULL) { 821 retval = -ENOMEM; 822 goto cleanup; 823 } 824 *private_data = minor; 825 dev_set_drvdata(hardware_device, private_data); 826 827 dev_file_info = comedi_get_device_file_info(minor); 828 829 memset(&it, 0, sizeof(it)); 830 strncpy(it.board_name, board_name, COMEDI_NAMELEN); 831 it.board_name[COMEDI_NAMELEN - 1] = '\0'; 832 BUG_ON(num_options > COMEDI_NDEVCONFOPTS); 833 memcpy(it.options, options, num_options * sizeof(int)); 834 835 mutex_lock(&dev_file_info->device->mutex); 836 retval = comedi_device_attach(dev_file_info->device, &it); 837 mutex_unlock(&dev_file_info->device->mutex); 838 839cleanup: 840 if (retval < 0) { 841 kfree(private_data); 842 comedi_free_board_minor(minor); 843 } 844 return retval; 845} 846 847void comedi_auto_unconfig(struct device *hardware_device) 848{ 849 unsigned *minor = (unsigned *)dev_get_drvdata(hardware_device); 850 if (minor == NULL) 851 return; 852 853 BUG_ON(*minor >= COMEDI_NUM_BOARD_MINORS); 854 855 comedi_free_board_minor(*minor); 856 dev_set_drvdata(hardware_device, NULL); 857 kfree(minor); 858} 859 860int comedi_pci_auto_config(struct pci_dev *pcidev, const char *board_name) 861{ 862 int options[2]; 863 864 /* pci bus */ 865 options[0] = pcidev->bus->number; 866 /* pci slot */ 867 options[1] = PCI_SLOT(pcidev->devfn); 868 869 return comedi_auto_config(&pcidev->dev, board_name, 870 options, ARRAY_SIZE(options)); 871} 872 873void comedi_pci_auto_unconfig(struct pci_dev *pcidev) 874{ 875 comedi_auto_unconfig(&pcidev->dev); 876} 877 878int comedi_usb_auto_config(struct usb_device *usbdev, const char *board_name) 879{ 880 BUG_ON(usbdev == NULL); 881 return comedi_auto_config(&usbdev->dev, board_name, NULL, 0); 882} 883 884void comedi_usb_auto_unconfig(struct usb_device *usbdev) 885{ 886 BUG_ON(usbdev == NULL); 887 comedi_auto_unconfig(&usbdev->dev); 888} 889