drivers.c revision ac4898a0f81d3b3c218cb4d17bac1750ef82e456
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 "wrapper.h" 42#include <linux/highmem.h> /* for SuSE brokenness */ 43#include <linux/vmalloc.h> 44#include <linux/cdev.h> 45#include <linux/dma-mapping.h> 46 47#include <linux/io.h> 48#include <asm/system.h> 49 50static int postconfig(struct comedi_device *dev); 51static int insn_rw_emulate_bits(struct comedi_device *dev, 52 struct comedi_subdevice *s, 53 struct comedi_insn *insn, unsigned int *data); 54static void *comedi_recognize(struct comedi_driver *driv, const char *name); 55static void comedi_report_boards(struct comedi_driver *driv); 56static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s); 57int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, 58 unsigned long new_size); 59 60struct comedi_driver *comedi_drivers; 61 62int comedi_modprobe(int minor) 63{ 64 return -EINVAL; 65} 66 67static void cleanup_device(struct comedi_device *dev) 68{ 69 int i; 70 struct comedi_subdevice *s; 71 72 if (dev->subdevices) { 73 for (i = 0; i < dev->n_subdevices; i++) { 74 s = dev->subdevices + i; 75 comedi_free_subdevice_minor(s); 76 if (s->async) { 77 comedi_buf_alloc(dev, s, 0); 78 kfree(s->async); 79 } 80 } 81 kfree(dev->subdevices); 82 dev->subdevices = NULL; 83 dev->n_subdevices = 0; 84 } 85 kfree(dev->private); 86 dev->private = NULL; 87 dev->driver = 0; 88 dev->board_name = NULL; 89 dev->board_ptr = NULL; 90 dev->iobase = 0; 91 dev->irq = 0; 92 dev->read_subdev = NULL; 93 dev->write_subdev = NULL; 94 dev->open = NULL; 95 dev->close = NULL; 96 comedi_set_hw_dev(dev, NULL); 97} 98 99static void __comedi_device_detach(struct comedi_device *dev) 100{ 101 dev->attached = 0; 102 if (dev->driver) 103 dev->driver->detach(dev); 104 else 105 printk(KERN_WARNING "BUG: dev->driver=NULL in comedi_device_detach()\n"); 106 cleanup_device(dev); 107} 108 109void comedi_device_detach(struct comedi_device *dev) 110{ 111 if (!dev->attached) 112 return; 113 __comedi_device_detach(dev); 114} 115 116int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it) 117{ 118 struct comedi_driver *driv; 119 int ret; 120 121 if (dev->attached) 122 return -EBUSY; 123 124 for (driv = comedi_drivers; driv; driv = driv->next) { 125 if (!try_module_get(driv->module)) { 126 printk 127 (KERN_INFO "comedi: failed to increment module count, skipping\n"); 128 continue; 129 } 130 if (driv->num_names) { 131 dev->board_ptr = comedi_recognize(driv, it->board_name); 132 if (dev->board_ptr == NULL) { 133 module_put(driv->module); 134 continue; 135 } 136 } else { 137 if (strcmp(driv->driver_name, it->board_name)) { 138 module_put(driv->module); 139 continue; 140 } 141 } 142 /* initialize dev->driver here so 143 * comedi_error() can be called from attach */ 144 dev->driver = driv; 145 ret = driv->attach(dev, it); 146 if (ret < 0) { 147 module_put(dev->driver->module); 148 __comedi_device_detach(dev); 149 return ret; 150 } 151 goto attached; 152 } 153 154 /* recognize has failed if we get here */ 155 /* report valid board names before returning error */ 156 for (driv = comedi_drivers; driv; driv = driv->next) { 157 if (!try_module_get(driv->module)) { 158 printk(KERN_INFO "comedi: failed to increment module count\n"); 159 continue; 160 } 161 comedi_report_boards(driv); 162 module_put(driv->module); 163 } 164 return -EIO; 165 166attached: 167 /* do a little post-config cleanup */ 168 ret = postconfig(dev); 169 module_put(dev->driver->module); 170 if (ret < 0) { 171 __comedi_device_detach(dev); 172 return ret; 173 } 174 175 if (!dev->board_name) { 176 printk(KERN_WARNING "BUG: dev->board_name=<%p>\n", dev->board_name); 177 dev->board_name = "BUG"; 178 } 179 smp_wmb(); 180 dev->attached = 1; 181 182 return 0; 183} 184 185int comedi_driver_register(struct comedi_driver *driver) 186{ 187 driver->next = comedi_drivers; 188 comedi_drivers = driver; 189 190 return 0; 191} 192 193int comedi_driver_unregister(struct comedi_driver *driver) 194{ 195 struct comedi_driver *prev; 196 int i; 197 198 /* check for devices using this driver */ 199 for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) { 200 struct comedi_device_file_info *dev_file_info = 201 comedi_get_device_file_info(i); 202 struct comedi_device *dev; 203 204 if (dev_file_info == NULL) 205 continue; 206 dev = dev_file_info->device; 207 208 mutex_lock(&dev->mutex); 209 if (dev->attached && dev->driver == driver) { 210 if (dev->use_count) 211 printk 212 (KERN_WARNING "BUG! detaching device with use_count=%d\n", 213 dev->use_count); 214 comedi_device_detach(dev); 215 } 216 mutex_unlock(&dev->mutex); 217 } 218 219 if (comedi_drivers == driver) { 220 comedi_drivers = driver->next; 221 return 0; 222 } 223 224 for (prev = comedi_drivers; prev->next; prev = prev->next) { 225 if (prev->next == driver) { 226 prev->next = driver->next; 227 return 0; 228 } 229 } 230 return -EINVAL; 231} 232 233static int postconfig(struct comedi_device *dev) 234{ 235 int i; 236 struct comedi_subdevice *s; 237 struct comedi_async *async = NULL; 238 int ret; 239 240 for (i = 0; i < dev->n_subdevices; i++) { 241 s = dev->subdevices + i; 242 243 if (s->type == COMEDI_SUBD_UNUSED) 244 continue; 245 246 if (s->len_chanlist == 0) 247 s->len_chanlist = 1; 248 249 if (s->do_cmd) { 250 BUG_ON((s->subdev_flags & (SDF_CMD_READ | 251 SDF_CMD_WRITE)) == 0); 252 BUG_ON(!s->do_cmdtest); 253 254 async = 255 kzalloc(sizeof(struct comedi_async), GFP_KERNEL); 256 if (async == NULL) { 257 printk(KERN_INFO "failed to allocate async struct\n"); 258 return -ENOMEM; 259 } 260 init_waitqueue_head(&async->wait_head); 261 async->subdevice = s; 262 s->async = async; 263 264#define DEFAULT_BUF_MAXSIZE (64*1024) 265#define DEFAULT_BUF_SIZE (64*1024) 266 267 async->max_bufsize = DEFAULT_BUF_MAXSIZE; 268 269 async->prealloc_buf = NULL; 270 async->prealloc_bufsz = 0; 271 if (comedi_buf_alloc(dev, s, DEFAULT_BUF_SIZE) < 0) { 272 printk(KERN_INFO "Buffer allocation failed\n"); 273 return -ENOMEM; 274 } 275 if (s->buf_change) { 276 ret = s->buf_change(dev, s, DEFAULT_BUF_SIZE); 277 if (ret < 0) 278 return ret; 279 } 280 comedi_alloc_subdevice_minor(dev, s); 281 } 282 283 if (!s->range_table && !s->range_table_list) 284 s->range_table = &range_unknown; 285 286 if (!s->insn_read && s->insn_bits) 287 s->insn_read = insn_rw_emulate_bits; 288 if (!s->insn_write && s->insn_bits) 289 s->insn_write = insn_rw_emulate_bits; 290 291 if (!s->insn_read) 292 s->insn_read = insn_inval; 293 if (!s->insn_write) 294 s->insn_write = insn_inval; 295 if (!s->insn_bits) 296 s->insn_bits = insn_inval; 297 if (!s->insn_config) 298 s->insn_config = insn_inval; 299 300 if (!s->poll) 301 s->poll = poll_invalid; 302 } 303 304 return 0; 305} 306 307/* generic recognize function for drivers 308 * that register their supported board names */ 309void *comedi_recognize(struct comedi_driver *driv, const char *name) 310{ 311 unsigned i; 312 const char *const *name_ptr = driv->board_name; 313 for (i = 0; i < driv->num_names; i++) { 314 if (strcmp(*name_ptr, name) == 0) 315 return (void *)name_ptr; 316 name_ptr = 317 (const char *const *)((const char *)name_ptr + 318 driv->offset); 319 } 320 321 return NULL; 322} 323 324void comedi_report_boards(struct comedi_driver *driv) 325{ 326 unsigned int i; 327 const char *const *name_ptr; 328 329 printk(KERN_INFO "comedi: valid board names for %s driver are:\n", 330 driv->driver_name); 331 332 name_ptr = driv->board_name; 333 for (i = 0; i < driv->num_names; i++) { 334 printk(KERN_INFO " %s\n", *name_ptr); 335 name_ptr = (const char **)((char *)name_ptr + driv->offset); 336 } 337 338 if (driv->num_names == 0) 339 printk(KERN_INFO " %s\n", driv->driver_name); 340} 341 342static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s) 343{ 344 return -EINVAL; 345} 346 347int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s, 348 struct comedi_insn *insn, unsigned int *data) 349{ 350 return -EINVAL; 351} 352 353static int insn_rw_emulate_bits(struct comedi_device *dev, 354 struct comedi_subdevice *s, 355 struct comedi_insn *insn, unsigned int *data) 356{ 357 struct comedi_insn new_insn; 358 int ret; 359 static const unsigned channels_per_bitfield = 32; 360 361 unsigned chan = CR_CHAN(insn->chanspec); 362 const unsigned base_bitfield_channel = 363 (chan < channels_per_bitfield) ? 0 : chan; 364 unsigned int new_data[2]; 365 memset(new_data, 0, sizeof(new_data)); 366 memset(&new_insn, 0, sizeof(new_insn)); 367 new_insn.insn = INSN_BITS; 368 new_insn.chanspec = base_bitfield_channel; 369 new_insn.n = 2; 370 new_insn.data = new_data; 371 new_insn.subdev = insn->subdev; 372 373 if (insn->insn == INSN_WRITE) { 374 if (!(s->subdev_flags & SDF_WRITABLE)) 375 return -EINVAL; 376 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */ 377 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel)) : 0; /* bits */ 378 } 379 380 ret = s->insn_bits(dev, s, &new_insn, new_data); 381 if (ret < 0) 382 return ret; 383 384 if (insn->insn == INSN_READ) 385 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1; 386 387 return 1; 388} 389 390static inline unsigned long uvirt_to_kva(pgd_t *pgd, unsigned long adr) 391{ 392 unsigned long ret = 0UL; 393 pmd_t *pmd; 394 pte_t *ptep, pte; 395 pud_t *pud; 396 397 if (!pgd_none(*pgd)) { 398 pud = pud_offset(pgd, adr); 399 pmd = pmd_offset(pud, adr); 400 if (!pmd_none(*pmd)) { 401 ptep = pte_offset_kernel(pmd, adr); 402 pte = *ptep; 403 if (pte_present(pte)) { 404 ret = (unsigned long) 405 page_address(pte_page(pte)); 406 ret |= (adr & (PAGE_SIZE - 1)); 407 } 408 } 409 } 410 return ret; 411} 412 413static inline unsigned long kvirt_to_kva(unsigned long adr) 414{ 415 unsigned long va, kva; 416 417 va = adr; 418 kva = uvirt_to_kva(pgd_offset_k(va), va); 419 420 return kva; 421} 422 423int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s, 424 unsigned long new_size) 425{ 426 struct comedi_async *async = s->async; 427 428 /* Round up new_size to multiple of PAGE_SIZE */ 429 new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK; 430 431 /* if no change is required, do nothing */ 432 if (async->prealloc_buf && async->prealloc_bufsz == new_size) 433 return 0; 434 435 /* deallocate old buffer */ 436 if (async->prealloc_buf) { 437 vunmap(async->prealloc_buf); 438 async->prealloc_buf = NULL; 439 async->prealloc_bufsz = 0; 440 } 441 if (async->buf_page_list) { 442 unsigned i; 443 for (i = 0; i < async->n_buf_pages; ++i) { 444 if (async->buf_page_list[i].virt_addr) { 445 mem_map_unreserve(virt_to_page 446 (async->buf_page_list[i]. 447 virt_addr)); 448 if (s->async_dma_dir != DMA_NONE) { 449 dma_free_coherent(dev->hw_dev, 450 PAGE_SIZE, 451 async-> 452 buf_page_list 453 [i].virt_addr, 454 async-> 455 buf_page_list 456 [i].dma_addr); 457 } else { 458 free_page((unsigned long) 459 async->buf_page_list[i]. 460 virt_addr); 461 } 462 } 463 } 464 vfree(async->buf_page_list); 465 async->buf_page_list = NULL; 466 async->n_buf_pages = 0; 467 } 468 /* allocate new buffer */ 469 if (new_size) { 470 unsigned i = 0; 471 unsigned n_pages = new_size >> PAGE_SHIFT; 472 struct page **pages = NULL; 473 474 async->buf_page_list = 475 vmalloc(sizeof(struct comedi_buf_page) * n_pages); 476 if (async->buf_page_list) { 477 memset(async->buf_page_list, 0, 478 sizeof(struct comedi_buf_page) * n_pages); 479 pages = vmalloc(sizeof(struct page *) * n_pages); 480 } 481 if (pages) { 482 for (i = 0; i < n_pages; i++) { 483 if (s->async_dma_dir != DMA_NONE) { 484 async->buf_page_list[i].virt_addr = 485 dma_alloc_coherent(dev->hw_dev, 486 PAGE_SIZE, 487 &async-> 488 buf_page_list 489 [i].dma_addr, 490 GFP_KERNEL | 491 __GFP_COMP); 492 } else { 493 async->buf_page_list[i].virt_addr = 494 (void *) 495 get_zeroed_page(GFP_KERNEL); 496 } 497 if (async->buf_page_list[i].virt_addr == NULL) 498 break; 499 500 mem_map_reserve(virt_to_page 501 (async->buf_page_list[i]. 502 virt_addr)); 503 pages[i] = 504 virt_to_page(async-> 505 buf_page_list[i].virt_addr); 506 } 507 } 508 if (i == n_pages) { 509 async->prealloc_buf = 510 vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE); 511 } 512 vfree(pages); 513 514 if (async->prealloc_buf == NULL) { 515 /* Some allocation failed above. */ 516 if (async->buf_page_list) { 517 for (i = 0; i < n_pages; i++) { 518 if (async->buf_page_list[i].virt_addr == 519 NULL) { 520 break; 521 } 522 mem_map_unreserve(virt_to_page 523 (async->buf_page_list 524 [i].virt_addr)); 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 */ 554unsigned 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 "%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 598unsigned 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 */ 618unsigned 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} 632 633/* allocates nothing unless it can completely fulfill the request */ 634unsigned int comedi_buf_write_alloc_strict(struct comedi_async *async, 635 unsigned int nbytes) 636{ 637 unsigned int free_end = async->buf_read_count + async->prealloc_bufsz; 638 639 if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0) 640 nbytes = 0; 641 642 async->buf_write_alloc_count += nbytes; 643 /* barrier insures the read of buf_read_count above occurs before 644 we write data to the write-alloc'ed buffer space */ 645 smp_mb(); 646 return nbytes; 647} 648 649/* transfers a chunk from writer to filled buffer space */ 650unsigned comedi_buf_write_free(struct comedi_async *async, unsigned int nbytes) 651{ 652 if ((int)(async->buf_write_count + nbytes - 653 async->buf_write_alloc_count) > 0) { 654 printk 655 (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} 666 667/* allocates a chunk for the reader from filled (and munged) buffer space */ 668unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes) 669{ 670 if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) > 671 0) { 672 nbytes = async->munge_count - async->buf_read_alloc_count; 673 } 674 async->buf_read_alloc_count += nbytes; 675 /* barrier insures read of munge_count occurs before we actually read 676 data out of buffer */ 677 smp_rmb(); 678 return nbytes; 679} 680 681/* transfers control of a chunk from reader to free buffer space */ 682unsigned comedi_buf_read_free(struct comedi_async *async, unsigned int nbytes) 683{ 684 /* barrier insures data has been read out of 685 * buffer before read count is incremented */ 686 smp_mb(); 687 if ((int)(async->buf_read_count + nbytes - 688 async->buf_read_alloc_count) > 0) { 689 printk 690 ("comedi: attempted to read-free more bytes than have been read-allocated.\n"); 691 nbytes = async->buf_read_alloc_count - async->buf_read_count; 692 } 693 async->buf_read_count += nbytes; 694 async->buf_read_ptr += nbytes; 695 async->buf_read_ptr %= async->prealloc_bufsz; 696 return nbytes; 697} 698 699void comedi_buf_memcpy_to(struct comedi_async *async, unsigned int offset, 700 const void *data, unsigned int num_bytes) 701{ 702 unsigned int write_ptr = async->buf_write_ptr + offset; 703 704 if (write_ptr >= async->prealloc_bufsz) 705 write_ptr %= async->prealloc_bufsz; 706 707 while (num_bytes) { 708 unsigned int block_size; 709 710 if (write_ptr + num_bytes > async->prealloc_bufsz) 711 block_size = async->prealloc_bufsz - write_ptr; 712 else 713 block_size = num_bytes; 714 715 memcpy(async->prealloc_buf + write_ptr, data, block_size); 716 717 data += block_size; 718 num_bytes -= block_size; 719 720 write_ptr = 0; 721 } 722} 723 724void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset, 725 void *dest, unsigned int nbytes) 726{ 727 void *src; 728 unsigned int read_ptr = async->buf_read_ptr + offset; 729 730 if (read_ptr >= async->prealloc_bufsz) 731 read_ptr %= async->prealloc_bufsz; 732 733 while (nbytes) { 734 unsigned int block_size; 735 736 src = async->prealloc_buf + read_ptr; 737 738 if (nbytes >= async->prealloc_bufsz - read_ptr) 739 block_size = async->prealloc_bufsz - read_ptr; 740 else 741 block_size = nbytes; 742 743 memcpy(dest, src, block_size); 744 nbytes -= block_size; 745 dest += block_size; 746 read_ptr = 0; 747 } 748} 749 750unsigned int comedi_buf_read_n_available(struct comedi_async *async) 751{ 752 unsigned num_bytes; 753 754 if (async == NULL) 755 return 0; 756 num_bytes = async->munge_count - async->buf_read_count; 757 /* barrier insures the read of munge_count in this 758 query occurs before any following reads of the buffer which 759 might be based on the return value from this query. 760 */ 761 smp_rmb(); 762 return num_bytes; 763} 764 765int comedi_buf_get(struct comedi_async *async, short *x) 766{ 767 unsigned int n = comedi_buf_read_n_available(async); 768 769 if (n < sizeof(short)) 770 return 0; 771 comedi_buf_read_alloc(async, sizeof(short)); 772 *x = *(short *)(async->prealloc_buf + async->buf_read_ptr); 773 comedi_buf_read_free(async, sizeof(short)); 774 return 1; 775} 776 777int comedi_buf_put(struct comedi_async *async, short x) 778{ 779 unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(short)); 780 781 if (n < sizeof(short)) { 782 async->events |= COMEDI_CB_ERROR; 783 return 0; 784 } 785 *(short *)(async->prealloc_buf + async->buf_write_ptr) = x; 786 comedi_buf_write_free(async, sizeof(short)); 787 return 1; 788} 789 790void comedi_reset_async_buf(struct comedi_async *async) 791{ 792 async->buf_write_alloc_count = 0; 793 async->buf_write_count = 0; 794 async->buf_read_alloc_count = 0; 795 async->buf_read_count = 0; 796 797 async->buf_write_ptr = 0; 798 async->buf_read_ptr = 0; 799 800 async->cur_chan = 0; 801 async->scan_progress = 0; 802 async->munge_chan = 0; 803 async->munge_count = 0; 804 async->munge_ptr = 0; 805 806 async->events = 0; 807} 808 809int comedi_auto_config(struct device *hardware_device, const char *board_name, 810 const int *options, unsigned num_options) 811{ 812 struct comedi_devconfig it; 813 int minor; 814 struct comedi_device_file_info *dev_file_info; 815 int retval; 816 unsigned *private_data = NULL; 817 818 if (!comedi_autoconfig) { 819 dev_set_drvdata(hardware_device, NULL); 820 return 0; 821 } 822 823 minor = comedi_alloc_board_minor(hardware_device); 824 if (minor < 0) 825 return minor; 826 827 private_data = kmalloc(sizeof(unsigned), GFP_KERNEL); 828 if (private_data == NULL) { 829 retval = -ENOMEM; 830 goto cleanup; 831 } 832 *private_data = minor; 833 dev_set_drvdata(hardware_device, private_data); 834 835 dev_file_info = comedi_get_device_file_info(minor); 836 837 memset(&it, 0, sizeof(it)); 838 strncpy(it.board_name, board_name, COMEDI_NAMELEN); 839 it.board_name[COMEDI_NAMELEN - 1] = '\0'; 840 BUG_ON(num_options > COMEDI_NDEVCONFOPTS); 841 memcpy(it.options, options, num_options * sizeof(int)); 842 843 mutex_lock(&dev_file_info->device->mutex); 844 retval = comedi_device_attach(dev_file_info->device, &it); 845 mutex_unlock(&dev_file_info->device->mutex); 846 847cleanup: 848 if (retval < 0) { 849 kfree(private_data); 850 comedi_free_board_minor(minor); 851 } 852 return retval; 853} 854 855void comedi_auto_unconfig(struct device *hardware_device) 856{ 857 unsigned *minor = (unsigned *)dev_get_drvdata(hardware_device); 858 if (minor == NULL) 859 return; 860 861 BUG_ON(*minor >= COMEDI_NUM_BOARD_MINORS); 862 863 comedi_free_board_minor(*minor); 864 dev_set_drvdata(hardware_device, NULL); 865 kfree(minor); 866} 867 868int comedi_pci_auto_config(struct pci_dev *pcidev, const char *board_name) 869{ 870 int options[2]; 871 872 /* pci bus */ 873 options[0] = pcidev->bus->number; 874 /* pci slot */ 875 options[1] = PCI_SLOT(pcidev->devfn); 876 877 return comedi_auto_config(&pcidev->dev, board_name, 878 options, ARRAY_SIZE(options)); 879} 880 881void comedi_pci_auto_unconfig(struct pci_dev *pcidev) 882{ 883 comedi_auto_unconfig(&pcidev->dev); 884} 885 886int comedi_usb_auto_config(struct usb_device *usbdev, const char *board_name) 887{ 888 BUG_ON(usbdev == NULL); 889 return comedi_auto_config(&usbdev->dev, board_name, NULL, 0); 890} 891 892void comedi_usb_auto_unconfig(struct usb_device *usbdev) 893{ 894 BUG_ON(usbdev == NULL); 895 comedi_auto_unconfig(&usbdev->dev); 896} 897