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