comedi/drivers.c

   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 <linux/device.h>
  28 #include <linux/module.h>
  29 #include <linux/pci.h>
  30 #include <linux/usb.h>
  31 #include <linux/errno.h>
  32 #include <linux/kernel.h>
  33 #include <linux/sched.h>
  34 #include <linux/fcntl.h>
  35 #include <linux/delay.h>
  36 #include <linux/ioport.h>
  37 #include <linux/mm.h>
  38 #include <linux/slab.h>
  39 #include <linux/comedidev.h>
  40 #include <linux/wrapper.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 <asm/io.h>
  47 #include <asm/system.h>
  48
  49 #include "comedi_fops.h"
  50
  51 static int postconfig(comedi_device * dev);
  52 static int insn_rw_emulate_bits(comedi_device * dev, comedi_subdevice * s,
  53         comedi_insn * insn, lsampl_t * data);
  54 static void *comedi_recognize(comedi_driver * driv, const char *name);
  55 static void comedi_report_boards(comedi_driver * driv);
  56 static int poll_invalid(comedi_device * dev, comedi_subdevice * s);
  57 int comedi_buf_alloc(comedi_device * dev, comedi_subdevice * s,
  58         unsigned long new_size);
  59
  60 comedi_driver *comedi_drivers;
  61
  62 int comedi_modprobe(int minor)
  63 {
  64         return -EINVAL;
  65 }
  66
  67 static void cleanup_device(comedi_device * dev)
  68 {
  69         int i;
  70         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         if (dev->private) {
  86                 kfree(dev->private);
  87                 dev->private = NULL;
  88         }
  89         dev->driver = 0;
  90         dev->board_name = NULL;
  91         dev->board_ptr = NULL;
  92         dev->iobase = 0;
  93         dev->irq = 0;
  94         dev->read_subdev = NULL;
  95         dev->write_subdev = NULL;
  96         dev->open = NULL;
  97         dev->close = NULL;
  98         comedi_set_hw_dev(dev, NULL);
  99 }
 100
 101 static void __comedi_device_detach(comedi_device * dev)
 102 {
 103         dev->attached = 0;
 104         if (dev->driver) {
 105                 dev->driver->detach(dev);
 106         } else {
 107                 printk("BUG: dev->driver=NULL in comedi_device_detach()\n");
 108         }
 109         cleanup_device(dev);
 110 }
 111
 112 void comedi_device_detach(comedi_device * dev)
 113 {
 114         if (!dev->attached)
 115                 return;
 116         __comedi_device_detach(dev);
 117 }
 118
 119 int comedi_device_attach(comedi_device * dev, comedi_devconfig * it)
 120 {
 121         comedi_driver *driv;
 122         int ret;
 123
 124         if (dev->attached)
 125                 return -EBUSY;
 126
 127         for (driv = comedi_drivers; driv; driv = driv->next) {
 128                 if (!try_module_get(driv->module)) {
 129                         printk("comedi: failed to increment module count, skipping\n");
 130                         continue;
 131                 }
 132                 if (driv->num_names) {
 133                         dev->board_ptr = comedi_recognize(driv, it->board_name);
 134                         if (dev->board_ptr == NULL) {
 135                                 module_put(driv->module);
 136                                 continue;
 137                         }
 138                 } else {
 139                         if (strcmp(driv->driver_name, it->board_name)) {
 140                                 module_put(driv->module);
 141                                 continue;
 142                         }
 143                 }
 144                 //initialize dev->driver here so comedi_error() can be called from attach
 145                 dev->driver = driv;
 146                 ret = driv->attach(dev, it);
 147                 if (ret < 0) {
 148                         module_put(dev->driver->module);
 149                         __comedi_device_detach(dev);
 150                         return ret;
 151                 }
 152                 goto attached;
 153         }
 154
 155         // recognize has failed if we get here
 156         // report valid board names before returning error
 157         for (driv = comedi_drivers; driv; driv = driv->next) {
 158                 if (!try_module_get(driv->module)) {
 159                         printk("comedi: failed to increment module count\n");
 160                         continue;
 161                 }
 162                 comedi_report_boards(driv);
 163                 module_put(driv->module);
 164         }
 165         return -EIO;
 166
 167 attached:
 168         /* do a little post-config cleanup */
 169         ret = postconfig(dev);
 170         module_put(dev->driver->module);
 171         if (ret < 0) {
 172                 __comedi_device_detach(dev);
 173                 return ret;
 174         }
 175
 176         if (!dev->board_name) {
 177                 printk("BUG: dev->board_name=<%p>\n", dev->board_name);
 178                 dev->board_name = "BUG";
 179         }
 180         smp_wmb();
 181         dev->attached = 1;
 182
 183         return 0;
 184 }
 185
 186 int comedi_driver_register(comedi_driver * driver)
 187 {
 188         driver->next = comedi_drivers;
 189         comedi_drivers = driver;
 190
 191         return 0;
 192 }
 193
 194 int comedi_driver_unregister(comedi_driver * driver)
 195 {
 196         comedi_driver *prev;
 197         int i;
 198
 199         /* check for devices using this driver */
 200         for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
 201                 struct comedi_device_file_info *dev_file_info = comedi_get_device_file_info(i);
 202                 comedi_device *dev;
 203
 204                 if(dev_file_info == NULL) 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("BUG! detaching device with use_count=%d\n", dev->use_count);
 211                         comedi_device_detach(dev);
 212                 }
 213                 mutex_unlock(&dev->mutex);
 214         }
 215
 216         if (comedi_drivers == driver) {
 217                 comedi_drivers = driver->next;
 218                 return 0;
 219         }
 220
 221         for (prev = comedi_drivers; prev->next; prev = prev->next) {
 222                 if (prev->next == driver) {
 223                         prev->next = driver->next;
 224                         return 0;
 225                 }
 226         }
 227         return -EINVAL;
 228 }
 229
 230 static int postconfig(comedi_device * dev)
 231 {
 232         int i;
 233         comedi_subdevice *s;
 234         comedi_async *async = NULL;
 235         int ret;
 236
 237         for (i = 0; i < dev->n_subdevices; i++) {
 238                 s = dev->subdevices + i;
 239
 240                 if (s->type == COMEDI_SUBD_UNUSED)
 241                         continue;
 242
 243                 if (s->len_chanlist == 0)
 244                         s->len_chanlist = 1;
 245
 246                 if (s->do_cmd) {
 247                         BUG_ON((s->subdev_flags & (SDF_CMD_READ |
 248                                 SDF_CMD_WRITE)) == 0);
 249                         BUG_ON(!s->do_cmdtest);
 250
 251                         async = kzalloc(sizeof(comedi_async), GFP_KERNEL);
 252                         if (async == NULL) {
 253                                 printk("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("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 that register their supported board names
 304 void *comedi_recognize(comedi_driver * driv, const char *name)
 305 {
 306         unsigned i;
 307         const char *const *name_ptr = driv->board_name;
 308         for (i = 0; i < driv->num_names; i++) {
 309                 if (strcmp(*name_ptr, name) == 0)
 310                         return (void *)name_ptr;
 311                 name_ptr =
 312                         (const char *const *)((const char *)name_ptr +
 313                         driv->offset);
 314         }
 315
 316         return NULL;
 317 }
 318
 319 void comedi_report_boards(comedi_driver * driv)
 320 {
 321         unsigned int i;
 322         const char *const *name_ptr;
 323
 324         printk("comedi: valid board names for %s driver are:\n",
 325                 driv->driver_name);
 326
 327         name_ptr = driv->board_name;
 328         for (i = 0; i < driv->num_names; i++) {
 329                 printk(" %s\n", *name_ptr);
 330                 name_ptr = (const char **)((char *)name_ptr + driv->offset);
 331         }
 332
 333         if (driv->num_names == 0)
 334                 printk(" %s\n", driv->driver_name);
 335 }
 336
 337 static int poll_invalid(comedi_device * dev, comedi_subdevice * s)
 338 {
 339         return -EINVAL;
 340 }
 341
 342 int insn_inval(comedi_device * dev, comedi_subdevice * s,
 343         comedi_insn * insn, lsampl_t * data)
 344 {
 345         return -EINVAL;
 346 }
 347
 348 static int insn_rw_emulate_bits(comedi_device * dev, comedi_subdevice * s,
 349         comedi_insn * insn, lsampl_t * data)
 350 {
 351         comedi_insn new_insn;
 352         int ret;
 353         static const unsigned channels_per_bitfield = 32;
 354         unsigned chan = CR_CHAN(insn->chanspec);
 355         const unsigned base_bitfield_channel =
 356                 (chan < channels_per_bitfield) ? 0 : chan;
 357         lsampl_t new_data[2];
 358
 359         if ((insn->insn == INSN_WRITE) && !(s->subdev_flags & SDF_WRITABLE))
 360                 return -EINVAL;
 361
 362         if (insn->n == 0)
 363                 return 0;
 364
 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                 new_data[0] = 1 << (chan - base_bitfield_channel);      /* mask */
 375                 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel)) : 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
 386         return 1;
 387 }
 388
 389 static 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
 412 static 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
 422 int comedi_buf_alloc(comedi_device * dev, comedi_subdevice * s,
 423         unsigned long new_size)
 424 {
 425         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                                 mem_map_unreserve(virt_to_page(async->
 445                                                 buf_page_list[i].virt_addr));
 446                                 if (s->async_dma_dir != DMA_NONE) {
 447                                         dma_free_coherent(dev->hw_dev,
 448                                                 PAGE_SIZE,
 449                                                 async->buf_page_list[i].
 450                                                 virt_addr,
 451                                                 async->buf_page_list[i].
 452                                                 dma_addr);
 453                                 } else {
 454                                         free_page((unsigned long)async->
 455                                                 buf_page_list[i].virt_addr);
 456                                 }
 457                         }
 458                 }
 459                 vfree(async->buf_page_list);
 460                 async->buf_page_list = NULL;
 461                 async->n_buf_pages = 0;
 462         }
 463         // allocate new buffer
 464         if (new_size) {
 465                 unsigned i = 0;
 466                 unsigned n_pages = new_size >> PAGE_SHIFT;
 467                 struct page **pages = NULL;
 468
 469                 async->buf_page_list =
 470                         vmalloc(sizeof(struct comedi_buf_page) * n_pages);
 471                 if (async->buf_page_list) {
 472                         memset(async->buf_page_list, 0,
 473                                 sizeof(struct comedi_buf_page) * n_pages);
 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->buf_page_list[i].
 483                                                 dma_addr,
 484                                                 GFP_KERNEL | __GFP_COMP);
 485                                 } else {
 486                                         async->buf_page_list[i].virt_addr =
 487                                                 (void *)
 488                                                 get_zeroed_page(GFP_KERNEL);
 489                                 }
 490                                 if (async->buf_page_list[i].virt_addr == NULL) {
 491                                         break;
 492                                 }
 493                                 mem_map_reserve(virt_to_page(async->
 494                                                 buf_page_list[i].virt_addr));
 495                                 pages[i] =
 496                                         virt_to_page(async->buf_page_list[i].
 497                                         virt_addr);
 498                         }
 499                 }
 500                 if (i == n_pages) {
 501                         async->prealloc_buf =
 502                                 vmap(pages, n_pages, VM_MAP,
 503                                 PAGE_KERNEL_NOCACHE);
 504                 }
 505                 if (pages) {
 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                                         mem_map_unreserve(virt_to_page(async->
 517                                                         buf_page_list[i].
 518                                                         virt_addr));
 519                                         if (s->async_dma_dir != DMA_NONE) {
 520                                                 dma_free_coherent(dev->hw_dev,
 521                                                         PAGE_SIZE,
 522                                                         async->buf_page_list[i].
 523                                                         virt_addr,
 524                                                         async->buf_page_list[i].
 525                                                         dma_addr);
 526                                         } else {
 527                                                 free_page((unsigned long)async->
 528                                                         buf_page_list[i].
 529                                                         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 */
 546 unsigned int comedi_buf_munge(comedi_async * async, unsigned int num_bytes)
 547 {
 548         comedi_subdevice *s = async->subdevice;
 549         unsigned int count = 0;
 550         const unsigned num_sample_bytes = bytes_per_sample(s);
 551
 552         if (s->munge == NULL || (async->cmd.flags & CMDF_RAWDATA)) {
 553                 async->munge_count += num_bytes;
 554                 if ((int)(async->munge_count - async->buf_write_count) > 0)
 555                         BUG();
 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                         rt_printk("%s: %s: bug! block_size is negative\n",
 566                                 __FILE__, __FUNCTION__);
 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 before munge_count is incremented
 577
 578                 async->munge_chan += block_size / num_sample_bytes;
 579                 async->munge_chan %= async->cmd.chanlist_len;
 580                 async->munge_count += block_size;
 581                 async->munge_ptr += block_size;
 582                 async->munge_ptr %= async->prealloc_bufsz;
 583                 count += block_size;
 584         }
 585         if ((int)(async->munge_count - async->buf_write_count) > 0)
 586                 BUG();
 587         return count;
 588 }
 589
 590 unsigned int comedi_buf_write_n_available(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 */
 610 unsigned int comedi_buf_write_alloc(comedi_async * async, unsigned int nbytes)
 611 {
 612         unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
 613
 614         if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0) {
 615                 nbytes = free_end - async->buf_write_alloc_count;
 616         }
 617         async->buf_write_alloc_count += nbytes;
 618         /* barrier insures the read of buf_read_count above occurs before
 619            we write data to the write-alloc'ed buffer space */
 620         smp_mb();
 621         return nbytes;
 622 }
 623
 624 /* allocates nothing unless it can completely fulfill the request */
 625 unsigned int comedi_buf_write_alloc_strict(comedi_async * async,
 626         unsigned int nbytes)
 627 {
 628         unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
 629
 630         if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0) {
 631                 nbytes = 0;
 632         }
 633         async->buf_write_alloc_count += nbytes;
 634         /* barrier insures the read of buf_read_count above occurs before
 635            we write data to the write-alloc'ed buffer space */
 636         smp_mb();
 637         return nbytes;
 638 }
 639
 640 /* transfers a chunk from writer to filled buffer space */
 641 unsigned comedi_buf_write_free(comedi_async * async, unsigned int nbytes)
 642 {
 643         if ((int)(async->buf_write_count + nbytes -
 644                         async->buf_write_alloc_count) > 0) {
 645                 rt_printk
 646                         ("comedi: attempted to write-free more bytes than have been write-allocated.\n");
 647                 nbytes = async->buf_write_alloc_count - async->buf_write_count;
 648         }
 649         async->buf_write_count += nbytes;
 650         async->buf_write_ptr += nbytes;
 651         comedi_buf_munge(async, async->buf_write_count - async->munge_count);
 652         if (async->buf_write_ptr >= async->prealloc_bufsz) {
 653                 async->buf_write_ptr %= async->prealloc_bufsz;
 654         }
 655         return nbytes;
 656 }
 657
 658 /* allocates a chunk for the reader from filled (and munged) buffer space */
 659 unsigned comedi_buf_read_alloc(comedi_async * async, unsigned nbytes)
 660 {
 661         if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) >
 662                 0) {
 663                 nbytes = async->munge_count - async->buf_read_alloc_count;
 664         }
 665         async->buf_read_alloc_count += nbytes;
 666         /* barrier insures read of munge_count occurs before we actually read
 667            data out of buffer */
 668         smp_rmb();
 669         return nbytes;
 670 }
 671
 672 /* transfers control of a chunk from reader to free buffer space */
 673 unsigned comedi_buf_read_free(comedi_async * async, unsigned int nbytes)
 674 {
 675         // barrier insures data has been read out of buffer before read count is incremented
 676         smp_mb();
 677         if ((int)(async->buf_read_count + nbytes -
 678                         async->buf_read_alloc_count) > 0) {
 679                 rt_printk
 680                         ("comedi: attempted to read-free more bytes than have been read-allocated.\n");
 681                 nbytes = async->buf_read_alloc_count - async->buf_read_count;
 682         }
 683         async->buf_read_count += nbytes;
 684         async->buf_read_ptr += nbytes;
 685         async->buf_read_ptr %= async->prealloc_bufsz;
 686         return nbytes;
 687 }
 688
 689 void comedi_buf_memcpy_to(comedi_async * async, unsigned int offset,
 690         const void *data, unsigned int num_bytes)
 691 {
 692         unsigned int write_ptr = async->buf_write_ptr + offset;
 693
 694         if (write_ptr >= async->prealloc_bufsz)
 695                 write_ptr %= async->prealloc_bufsz;
 696
 697         while (num_bytes) {
 698                 unsigned int block_size;
 699
 700                 if (write_ptr + num_bytes > async->prealloc_bufsz)
 701                         block_size = async->prealloc_bufsz - write_ptr;
 702                 else
 703                         block_size = num_bytes;
 704
 705                 memcpy(async->prealloc_buf + write_ptr, data, block_size);
 706
 707                 data += block_size;
 708                 num_bytes -= block_size;
 709
 710                 write_ptr = 0;
 711         }
 712 }
 713
 714 void comedi_buf_memcpy_from(comedi_async * async, unsigned int offset,
 715         void *dest, unsigned int nbytes)
 716 {
 717         void *src;
 718         unsigned int read_ptr = async->buf_read_ptr + offset;
 719
 720         if (read_ptr >= async->prealloc_bufsz)
 721                 read_ptr %= async->prealloc_bufsz;
 722
 723         while (nbytes) {
 724                 unsigned int block_size;
 725
 726                 src = async->prealloc_buf + read_ptr;
 727
 728                 if (nbytes >= async->prealloc_bufsz - read_ptr)
 729                         block_size = async->prealloc_bufsz - read_ptr;
 730                 else
 731                         block_size = nbytes;
 732
 733                 memcpy(dest, src, block_size);
 734                 nbytes -= block_size;
 735                 dest += block_size;
 736                 read_ptr = 0;
 737         }
 738 }
 739
 740 unsigned int comedi_buf_read_n_available(comedi_async * async)
 741 {
 742         unsigned num_bytes;
 743
 744         if (async == NULL)
 745                 return 0;
 746         num_bytes = async->munge_count - async->buf_read_count;
 747         /* barrier insures the read of munge_count in this
 748            query occurs before any following reads of the buffer which
 749            might be based on the return value from this query.
 750          */
 751         smp_rmb();
 752         return num_bytes;
 753 }
 754
 755 int comedi_buf_get(comedi_async * async, sampl_t * x)
 756 {
 757         unsigned int n = comedi_buf_read_n_available(async);
 758
 759         if (n < sizeof(sampl_t))
 760                 return 0;
 761         comedi_buf_read_alloc(async, sizeof(sampl_t));
 762         *x = *(sampl_t *) (async->prealloc_buf + async->buf_read_ptr);
 763         comedi_buf_read_free(async, sizeof(sampl_t));
 764         return 1;
 765 }
 766
 767 int comedi_buf_put(comedi_async * async, sampl_t x)
 768 {
 769         unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(sampl_t));
 770
 771         if (n < sizeof(sampl_t)) {
 772                 async->events |= COMEDI_CB_ERROR;
 773                 return 0;
 774         }
 775         *(sampl_t *) (async->prealloc_buf + async->buf_write_ptr) = x;
 776         comedi_buf_write_free(async, sizeof(sampl_t));
 777         return 1;
 778 }
 779
 780 void comedi_reset_async_buf(comedi_async * async)
 781 {
 782         async->buf_write_alloc_count = 0;
 783         async->buf_write_count = 0;
 784         async->buf_read_alloc_count = 0;
 785         async->buf_read_count = 0;
 786
 787         async->buf_write_ptr = 0;
 788         async->buf_read_ptr = 0;
 789
 790         async->cur_chan = 0;
 791         async->scan_progress = 0;
 792         async->munge_chan = 0;
 793         async->munge_count = 0;
 794         async->munge_ptr = 0;
 795
 796         async->events = 0;
 797 }
 798
 799 int comedi_auto_config(struct device *hardware_device, const char *board_name, const int *options, unsigned num_options)
 800 {
 801         comedi_devconfig it;
 802         int minor;
 803         struct comedi_device_file_info *dev_file_info;
 804         int retval;
 805         unsigned *private_data = NULL;
 806
 807         if(!comedi_autoconfig) {
 808                 dev_set_drvdata(hardware_device, NULL);
 809                 return 0;
 810         }
 811
 812         minor = comedi_alloc_board_minor(hardware_device);
 813         if(minor < 0) return minor;
 814
 815         private_data = kmalloc(sizeof(unsigned), GFP_KERNEL);
 816         if(private_data == NULL) {
 817                 retval = -ENOMEM;
 818                 goto cleanup;
 819         }
 820         *private_data = minor;
 821         dev_set_drvdata(hardware_device, private_data);
 822
 823         dev_file_info = comedi_get_device_file_info(minor);
 824
 825         memset(&it, 0, sizeof(it));
 826         strncpy(it.board_name, board_name, COMEDI_NAMELEN);
 827         it.board_name[COMEDI_NAMELEN - 1] = '\0';
 828         BUG_ON(num_options > COMEDI_NDEVCONFOPTS);
 829         memcpy(it.options, options, num_options * sizeof(int));
 830
 831         mutex_lock(&dev_file_info->device->mutex);
 832         retval = comedi_device_attach(dev_file_info->device, &it);
 833         mutex_unlock(&dev_file_info->device->mutex);
 834
 835 cleanup:
 836         if(retval < 0)
 837         {
 838                 kfree(private_data);
 839                 comedi_free_board_minor(minor);
 840         }
 841         return retval;
 842 }
 843
 844 void comedi_auto_unconfig(struct device *hardware_device)
 845 {
 846         unsigned *minor = (unsigned *)dev_get_drvdata(hardware_device);
 847         if(minor == NULL) return;
 848
 849         BUG_ON(*minor >= COMEDI_NUM_BOARD_MINORS);
 850
 851         comedi_free_board_minor(*minor);
 852         dev_set_drvdata(hardware_device, NULL);
 853         kfree(minor);
 854 }
 855
 856 int comedi_pci_auto_config(struct pci_dev *pcidev, const char *board_name)
 857 {
 858         int options[2];
 859
 860         // pci bus
 861         options[0] = pcidev->bus->number;
 862         // pci slot
 863         options[1] = PCI_SLOT(pcidev->devfn);
 864
 865         return comedi_auto_config(&pcidev->dev, board_name, options, sizeof(options) / sizeof(options[0]));
 866 }
 867
 868 void comedi_pci_auto_unconfig(struct pci_dev *pcidev)
 869 {
 870         comedi_auto_unconfig(&pcidev->dev);
 871 }
 872
 873 int comedi_usb_auto_config(struct usb_device *usbdev,
 874         const char *board_name)
 875 {
 876         BUG_ON(usbdev == NULL);
 877         return comedi_auto_config(&usbdev->dev, board_name, NULL, 0);
 878 }
 879
 880 void comedi_usb_auto_unconfig(struct usb_device *usbdev)
 881 {
 882         BUG_ON(usbdev == NULL);
 883         comedi_auto_unconfig(&usbdev->dev);
 884 }