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 <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/kconfig.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 "comedi_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 int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
  60 {
  61         struct comedi_subdevice *s;
  62         int i;
  63
  64         if (num_subdevices < 1)
  65                 return -EINVAL;
  66
  67         s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL);
  68         if (!s)
  69                 return -ENOMEM;
  70         dev->subdevices = s;
  71         dev->n_subdevices = num_subdevices;
  72
  73         for (i = 0; i < num_subdevices; ++i) {
  74                 s = dev->subdevices + i;
  75                 s->device = dev;
  76                 s->async_dma_dir = DMA_NONE;
  77                 spin_lock_init(&s->spin_lock);
  78                 s->minor = -1;
  79         }
  80         return 0;
  81 }
  82 EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
  83
  84 static void cleanup_device(struct comedi_device *dev)
  85 {
  86         int i;
  87         struct comedi_subdevice *s;
  88
  89         if (dev->subdevices) {
  90                 for (i = 0; i < dev->n_subdevices; i++) {
  91                         s = dev->subdevices + i;
  92                         comedi_free_subdevice_minor(s);
  93                         if (s->async) {
  94                                 comedi_buf_alloc(dev, s, 0);
  95                                 kfree(s->async);
  96                         }
  97                 }
  98                 kfree(dev->subdevices);
  99                 dev->subdevices = NULL;
 100                 dev->n_subdevices = 0;
 101         }
 102         kfree(dev->private);
 103         dev->private = NULL;
 104         dev->driver = NULL;
 105         dev->board_name = NULL;
 106         dev->board_ptr = NULL;
 107         dev->iobase = 0;
 108         dev->irq = 0;
 109         dev->read_subdev = NULL;
 110         dev->write_subdev = NULL;
 111         dev->open = NULL;
 112         dev->close = NULL;
 113         comedi_set_hw_dev(dev, NULL);
 114 }
 115
 116 static void __comedi_device_detach(struct comedi_device *dev)
 117 {
 118         dev->attached = 0;
 119         if (dev->driver)
 120                 dev->driver->detach(dev);
 121         else
 122                 printk(KERN_WARNING
 123                        "BUG: dev->driver=NULL in comedi_device_detach()\n");
 124         cleanup_device(dev);
 125 }
 126
 127 void comedi_device_detach(struct comedi_device *dev)
 128 {
 129         if (!dev->attached)
 130                 return;
 131         __comedi_device_detach(dev);
 132 }
 133
 134 /* do a little post-config cleanup */
 135 /* called with module refcount incremented, decrements it */
 136 static int comedi_device_postconfig(struct comedi_device *dev)
 137 {
 138         int ret = postconfig(dev);
 139         module_put(dev->driver->module);
 140         if (ret < 0) {
 141                 __comedi_device_detach(dev);
 142                 return ret;
 143         }
 144         if (!dev->board_name) {
 145                 printk(KERN_WARNING "BUG: dev->board_name=<%p>\n",
 146                        dev->board_name);
 147                 dev->board_name = "BUG";
 148         }
 149         smp_wmb();
 150         dev->attached = 1;
 151         return 0;
 152 }
 153
 154 int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 155 {
 156         struct comedi_driver *driv;
 157         int ret;
 158
 159         if (dev->attached)
 160                 return -EBUSY;
 161
 162         for (driv = comedi_drivers; driv; driv = driv->next) {
 163                 if (!try_module_get(driv->module)) {
 164                         printk(KERN_INFO "comedi: failed to increment module count, skipping\n");
 165                         continue;
 166                 }
 167                 if (driv->num_names) {
 168                         dev->board_ptr = comedi_recognize(driv, it->board_name);
 169                         if (dev->board_ptr)
 170                                 break;
 171                 } else if (strcmp(driv->driver_name, it->board_name))
 172                         break;
 173                 module_put(driv->module);
 174         }
 175         if (driv == NULL) {
 176                 /*  recognize has failed if we get here */
 177                 /*  report valid board names before returning error */
 178                 for (driv = comedi_drivers; driv; driv = driv->next) {
 179                         if (!try_module_get(driv->module)) {
 180                                 printk(KERN_INFO
 181                                        "comedi: failed to increment module count\n");
 182                                 continue;
 183                         }
 184                         comedi_report_boards(driv);
 185                         module_put(driv->module);
 186                 }
 187                 return -EIO;
 188         }
 189         /* initialize dev->driver here so
 190          * comedi_error() can be called from attach */
 191         dev->driver = driv;
 192         ret = driv->attach(dev, it);
 193         if (ret < 0) {
 194                 module_put(dev->driver->module);
 195                 __comedi_device_detach(dev);
 196                 return ret;
 197         }
 198         return comedi_device_postconfig(dev);
 199 }
 200
 201 int comedi_driver_register(struct comedi_driver *driver)
 202 {
 203         driver->next = comedi_drivers;
 204         comedi_drivers = driver;
 205
 206         return 0;
 207 }
 208 EXPORT_SYMBOL(comedi_driver_register);
 209
 210 int comedi_driver_unregister(struct comedi_driver *driver)
 211 {
 212         struct comedi_driver *prev;
 213         int i;
 214
 215         /* check for devices using this driver */
 216         for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
 217                 struct comedi_device_file_info *dev_file_info =
 218                     comedi_get_device_file_info(i);
 219                 struct comedi_device *dev;
 220
 221                 if (dev_file_info == NULL)
 222                         continue;
 223                 dev = dev_file_info->device;
 224
 225                 mutex_lock(&dev->mutex);
 226                 if (dev->attached && dev->driver == driver) {
 227                         if (dev->use_count)
 228                                 printk(KERN_WARNING "BUG! detaching device with use_count=%d\n",
 229                                                 dev->use_count);
 230                         comedi_device_detach(dev);
 231                 }
 232                 mutex_unlock(&dev->mutex);
 233         }
 234
 235         if (comedi_drivers == driver) {
 236                 comedi_drivers = driver->next;
 237                 return 0;
 238         }
 239
 240         for (prev = comedi_drivers; prev->next; prev = prev->next) {
 241                 if (prev->next == driver) {
 242                         prev->next = driver->next;
 243                         return 0;
 244                 }
 245         }
 246         return -EINVAL;
 247 }
 248 EXPORT_SYMBOL(comedi_driver_unregister);
 249
 250 static int postconfig(struct comedi_device *dev)
 251 {
 252         int i;
 253         struct comedi_subdevice *s;
 254         struct comedi_async *async = NULL;
 255         int ret;
 256
 257         for (i = 0; i < dev->n_subdevices; i++) {
 258                 s = dev->subdevices + i;
 259
 260                 if (s->type == COMEDI_SUBD_UNUSED)
 261                         continue;
 262
 263                 if (s->len_chanlist == 0)
 264                         s->len_chanlist = 1;
 265
 266                 if (s->do_cmd) {
 267                         unsigned int buf_size;
 268
 269                         BUG_ON((s->subdev_flags & (SDF_CMD_READ |
 270                                                    SDF_CMD_WRITE)) == 0);
 271                         BUG_ON(!s->do_cmdtest);
 272
 273                         async =
 274                             kzalloc(sizeof(struct comedi_async), GFP_KERNEL);
 275                         if (async == NULL) {
 276                                 printk(KERN_INFO
 277                                        "failed to allocate async struct\n");
 278                                 return -ENOMEM;
 279                         }
 280                         init_waitqueue_head(&async->wait_head);
 281                         async->subdevice = s;
 282                         s->async = async;
 283
 284                         async->max_bufsize =
 285                                 comedi_default_buf_maxsize_kb * 1024;
 286                         buf_size = comedi_default_buf_size_kb * 1024;
 287                         if (buf_size > async->max_bufsize)
 288                                 buf_size = async->max_bufsize;
 289
 290                         async->prealloc_buf = NULL;
 291                         async->prealloc_bufsz = 0;
 292                         if (comedi_buf_alloc(dev, s, buf_size) < 0) {
 293                                 printk(KERN_INFO "Buffer allocation failed\n");
 294                                 return -ENOMEM;
 295                         }
 296                         if (s->buf_change) {
 297                                 ret = s->buf_change(dev, s, buf_size);
 298                                 if (ret < 0)
 299                                         return ret;
 300                         }
 301                         comedi_alloc_subdevice_minor(dev, s);
 302                 }
 303
 304                 if (!s->range_table && !s->range_table_list)
 305                         s->range_table = &range_unknown;
 306
 307                 if (!s->insn_read && s->insn_bits)
 308                         s->insn_read = insn_rw_emulate_bits;
 309                 if (!s->insn_write && s->insn_bits)
 310                         s->insn_write = insn_rw_emulate_bits;
 311
 312                 if (!s->insn_read)
 313                         s->insn_read = insn_inval;
 314                 if (!s->insn_write)
 315                         s->insn_write = insn_inval;
 316                 if (!s->insn_bits)
 317                         s->insn_bits = insn_inval;
 318                 if (!s->insn_config)
 319                         s->insn_config = insn_inval;
 320
 321                 if (!s->poll)
 322                         s->poll = poll_invalid;
 323         }
 324
 325         return 0;
 326 }
 327
 328 /*
 329  * Generic recognize function for drivers that register their supported
 330  * board names.
 331  *
 332  * 'driv->board_name' points to a 'const char *' member within the
 333  * zeroth element of an array of some private board information
 334  * structure, say 'struct foo_board' containing a member 'const char
 335  * *board_name' that is initialized to point to a board name string that
 336  * is one of the candidates matched against this function's 'name'
 337  * parameter.
 338  *
 339  * 'driv->offset' is the size of the private board information
 340  * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is
 341  * the length of the array of private board information structures.
 342  *
 343  * If one of the board names in the array of private board information
 344  * structures matches the name supplied to this function, the function
 345  * returns a pointer to the pointer to the board name, otherwise it
 346  * returns NULL.  The return value ends up in the 'board_ptr' member of
 347  * a 'struct comedi_device' that the low-level comedi driver's
 348  * 'attach()' hook can convert to a point to a particular element of its
 349  * array of private board information structures by subtracting the
 350  * offset of the member that points to the board name.  (No subtraction
 351  * is required if the board name pointer is the first member of the
 352  * private board information structure, which is generally the case.)
 353  */
 354 static void *comedi_recognize(struct comedi_driver *driv, const char *name)
 355 {
 356         char **name_ptr = (char **)driv->board_name;
 357         int i;
 358
 359         for (i = 0; i < driv->num_names; i++) {
 360                 if (strcmp(*name_ptr, name) == 0)
 361                         return name_ptr;
 362                 name_ptr = (void *)name_ptr + driv->offset;
 363         }
 364
 365         return NULL;
 366 }
 367
 368 static void comedi_report_boards(struct comedi_driver *driv)
 369 {
 370         unsigned int i;
 371         const char *const *name_ptr;
 372
 373         printk(KERN_INFO "comedi: valid board names for %s driver are:\n",
 374                driv->driver_name);
 375
 376         name_ptr = driv->board_name;
 377         for (i = 0; i < driv->num_names; i++) {
 378                 printk(KERN_INFO " %s\n", *name_ptr);
 379                 name_ptr = (const char **)((char *)name_ptr + driv->offset);
 380         }
 381
 382         if (driv->num_names == 0)
 383                 printk(KERN_INFO " %s\n", driv->driver_name);
 384 }
 385
 386 static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
 387 {
 388         return -EINVAL;
 389 }
 390
 391 int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
 392                struct comedi_insn *insn, unsigned int *data)
 393 {
 394         return -EINVAL;
 395 }
 396
 397 static int insn_rw_emulate_bits(struct comedi_device *dev,
 398                                 struct comedi_subdevice *s,
 399                                 struct comedi_insn *insn, unsigned int *data)
 400 {
 401         struct comedi_insn new_insn;
 402         int ret;
 403         static const unsigned channels_per_bitfield = 32;
 404
 405         unsigned chan = CR_CHAN(insn->chanspec);
 406         const unsigned base_bitfield_channel =
 407             (chan < channels_per_bitfield) ? 0 : chan;
 408         unsigned int new_data[2];
 409         memset(new_data, 0, sizeof(new_data));
 410         memset(&new_insn, 0, sizeof(new_insn));
 411         new_insn.insn = INSN_BITS;
 412         new_insn.chanspec = base_bitfield_channel;
 413         new_insn.n = 2;
 414         new_insn.data = new_data;
 415         new_insn.subdev = insn->subdev;
 416
 417         if (insn->insn == INSN_WRITE) {
 418                 if (!(s->subdev_flags & SDF_WRITABLE))
 419                         return -EINVAL;
 420                 new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
 421                 new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
 422                               : 0; /* bits */
 423         }
 424
 425         ret = s->insn_bits(dev, s, &new_insn, new_data);
 426         if (ret < 0)
 427                 return ret;
 428
 429         if (insn->insn == INSN_READ)
 430                 data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
 431
 432         return 1;
 433 }
 434
 435 int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
 436                      unsigned long new_size)
 437 {
 438         struct comedi_async *async = s->async;
 439
 440         /* Round up new_size to multiple of PAGE_SIZE */
 441         new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
 442
 443         /* if no change is required, do nothing */
 444         if (async->prealloc_buf && async->prealloc_bufsz == new_size)
 445                 return 0;
 446
 447         /*  deallocate old buffer */
 448         if (async->prealloc_buf) {
 449                 vunmap(async->prealloc_buf);
 450                 async->prealloc_buf = NULL;
 451                 async->prealloc_bufsz = 0;
 452         }
 453         if (async->buf_page_list) {
 454                 unsigned i;
 455                 for (i = 0; i < async->n_buf_pages; ++i) {
 456                         if (async->buf_page_list[i].virt_addr) {
 457                                 clear_bit(PG_reserved,
 458                                         &(virt_to_page(async->buf_page_list[i].
 459                                                         virt_addr)->flags));
 460                                 if (s->async_dma_dir != DMA_NONE) {
 461                                         dma_free_coherent(dev->hw_dev,
 462                                                           PAGE_SIZE,
 463                                                           async->
 464                                                           buf_page_list
 465                                                           [i].virt_addr,
 466                                                           async->
 467                                                           buf_page_list
 468                                                           [i].dma_addr);
 469                                 } else {
 470                                         free_page((unsigned long)
 471                                                   async->buf_page_list[i].
 472                                                   virt_addr);
 473                                 }
 474                         }
 475                 }
 476                 vfree(async->buf_page_list);
 477                 async->buf_page_list = NULL;
 478                 async->n_buf_pages = 0;
 479         }
 480         /*  allocate new buffer */
 481         if (new_size) {
 482                 unsigned i = 0;
 483                 unsigned n_pages = new_size >> PAGE_SHIFT;
 484                 struct page **pages = NULL;
 485
 486                 async->buf_page_list =
 487                     vzalloc(sizeof(struct comedi_buf_page) * n_pages);
 488                 if (async->buf_page_list)
 489                         pages = vmalloc(sizeof(struct page *) * n_pages);
 490
 491                 if (pages) {
 492                         for (i = 0; i < n_pages; i++) {
 493                                 if (s->async_dma_dir != DMA_NONE) {
 494                                         async->buf_page_list[i].virt_addr =
 495                                             dma_alloc_coherent(dev->hw_dev,
 496                                                                PAGE_SIZE,
 497                                                                &async->
 498                                                                buf_page_list
 499                                                                [i].dma_addr,
 500                                                                GFP_KERNEL |
 501                                                                __GFP_COMP);
 502                                 } else {
 503                                         async->buf_page_list[i].virt_addr =
 504                                             (void *)
 505                                             get_zeroed_page(GFP_KERNEL);
 506                                 }
 507                                 if (async->buf_page_list[i].virt_addr == NULL)
 508                                         break;
 509
 510                                 set_bit(PG_reserved,
 511                                         &(virt_to_page(async->buf_page_list[i].
 512                                                         virt_addr)->flags));
 513                                 pages[i] = virt_to_page(async->buf_page_list[i].
 514                                                                 virt_addr);
 515                         }
 516                 }
 517                 if (i == n_pages) {
 518                         async->prealloc_buf =
 519 #ifdef PAGE_KERNEL_NOCACHE
 520                             vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
 521 #else
 522                             vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
 523 #endif
 524                 }
 525                 vfree(pages);
 526
 527                 if (async->prealloc_buf == NULL) {
 528                         /* Some allocation failed above. */
 529                         if (async->buf_page_list) {
 530                                 for (i = 0; i < n_pages; i++) {
 531                                         if (async->buf_page_list[i].virt_addr ==
 532                                             NULL) {
 533                                                 break;
 534                                         }
 535                                         clear_bit(PG_reserved,
 536                                                 &(virt_to_page(async->
 537                                                         buf_page_list[i].
 538                                                         virt_addr)->flags));
 539                                         if (s->async_dma_dir != DMA_NONE) {
 540                                                 dma_free_coherent(dev->hw_dev,
 541                                                                   PAGE_SIZE,
 542                                                                   async->
 543                                                                   buf_page_list
 544                                                                   [i].virt_addr,
 545                                                                   async->
 546                                                                   buf_page_list
 547                                                                   [i].dma_addr);
 548                                         } else {
 549                                                 free_page((unsigned long)
 550                                                           async->buf_page_list
 551                                                           [i].virt_addr);
 552                                         }
 553                                 }
 554                                 vfree(async->buf_page_list);
 555                                 async->buf_page_list = NULL;
 556                         }
 557                         return -ENOMEM;
 558                 }
 559                 async->n_buf_pages = n_pages;
 560         }
 561         async->prealloc_bufsz = new_size;
 562
 563         return 0;
 564 }
 565
 566 /* munging is applied to data by core as it passes between user
 567  * and kernel space */
 568 static unsigned int comedi_buf_munge(struct comedi_async *async,
 569                                      unsigned int num_bytes)
 570 {
 571         struct comedi_subdevice *s = async->subdevice;
 572         unsigned int count = 0;
 573         const unsigned num_sample_bytes = bytes_per_sample(s);
 574
 575         if (s->munge == NULL || (async->cmd.flags & CMDF_RAWDATA)) {
 576                 async->munge_count += num_bytes;
 577                 BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
 578                 return num_bytes;
 579         }
 580         /* don't munge partial samples */
 581         num_bytes -= num_bytes % num_sample_bytes;
 582         while (count < num_bytes) {
 583                 int block_size;
 584
 585                 block_size = num_bytes - count;
 586                 if (block_size < 0) {
 587                         printk(KERN_WARNING
 588                                "%s: %s: bug! block_size is negative\n",
 589                                __FILE__, __func__);
 590                         break;
 591                 }
 592                 if ((int)(async->munge_ptr + block_size -
 593                           async->prealloc_bufsz) > 0)
 594                         block_size = async->prealloc_bufsz - async->munge_ptr;
 595
 596                 s->munge(s->device, s, async->prealloc_buf + async->munge_ptr,
 597                          block_size, async->munge_chan);
 598
 599                 smp_wmb();      /* barrier insures data is munged in buffer
 600                                  * before munge_count is incremented */
 601
 602                 async->munge_chan += block_size / num_sample_bytes;
 603                 async->munge_chan %= async->cmd.chanlist_len;
 604                 async->munge_count += block_size;
 605                 async->munge_ptr += block_size;
 606                 async->munge_ptr %= async->prealloc_bufsz;
 607                 count += block_size;
 608         }
 609         BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
 610         return count;
 611 }
 612
 613 unsigned int comedi_buf_write_n_available(struct comedi_async *async)
 614 {
 615         unsigned int free_end;
 616         unsigned int nbytes;
 617
 618         if (async == NULL)
 619                 return 0;
 620
 621         free_end = async->buf_read_count + async->prealloc_bufsz;
 622         nbytes = free_end - async->buf_write_alloc_count;
 623         nbytes -= nbytes % bytes_per_sample(async->subdevice);
 624         /* barrier insures the read of buf_read_count in this
 625            query occurs before any following writes to the buffer which
 626            might be based on the return value from this query.
 627          */
 628         smp_mb();
 629         return nbytes;
 630 }
 631
 632 /* allocates chunk for the writer from free buffer space */
 633 unsigned int comedi_buf_write_alloc(struct comedi_async *async,
 634                                     unsigned int nbytes)
 635 {
 636         unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
 637
 638         if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
 639                 nbytes = free_end - async->buf_write_alloc_count;
 640
 641         async->buf_write_alloc_count += nbytes;
 642         /* barrier insures the read of buf_read_count above occurs before
 643            we write data to the write-alloc'ed buffer space */
 644         smp_mb();
 645         return nbytes;
 646 }
 647 EXPORT_SYMBOL(comedi_buf_write_alloc);
 648
 649 /* allocates nothing unless it can completely fulfill the request */
 650 unsigned int comedi_buf_write_alloc_strict(struct comedi_async *async,
 651                                            unsigned int nbytes)
 652 {
 653         unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
 654
 655         if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0)
 656                 nbytes = 0;
 657
 658         async->buf_write_alloc_count += nbytes;
 659         /* barrier insures the read of buf_read_count above occurs before
 660            we write data to the write-alloc'ed buffer space */
 661         smp_mb();
 662         return nbytes;
 663 }
 664
 665 /* transfers a chunk from writer to filled buffer space */
 666 unsigned comedi_buf_write_free(struct comedi_async *async, unsigned int nbytes)
 667 {
 668         if ((int)(async->buf_write_count + nbytes -
 669                   async->buf_write_alloc_count) > 0) {
 670                 printk(KERN_INFO "comedi: attempted to write-free more bytes than have been write-allocated.\n");
 671                 nbytes = async->buf_write_alloc_count - async->buf_write_count;
 672         }
 673         async->buf_write_count += nbytes;
 674         async->buf_write_ptr += nbytes;
 675         comedi_buf_munge(async, async->buf_write_count - async->munge_count);
 676         if (async->buf_write_ptr >= async->prealloc_bufsz)
 677                 async->buf_write_ptr %= async->prealloc_bufsz;
 678
 679         return nbytes;
 680 }
 681 EXPORT_SYMBOL(comedi_buf_write_free);
 682
 683 /* allocates a chunk for the reader from filled (and munged) buffer space */
 684 unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes)
 685 {
 686         if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) >
 687             0) {
 688                 nbytes = async->munge_count - async->buf_read_alloc_count;
 689         }
 690         async->buf_read_alloc_count += nbytes;
 691         /* barrier insures read of munge_count occurs before we actually read
 692            data out of buffer */
 693         smp_rmb();
 694         return nbytes;
 695 }
 696 EXPORT_SYMBOL(comedi_buf_read_alloc);
 697
 698 /* transfers control of a chunk from reader to free buffer space */
 699 unsigned comedi_buf_read_free(struct comedi_async *async, unsigned int nbytes)
 700 {
 701         /* barrier insures data has been read out of
 702          * buffer before read count is incremented */
 703         smp_mb();
 704         if ((int)(async->buf_read_count + nbytes -
 705                   async->buf_read_alloc_count) > 0) {
 706                 printk(KERN_INFO
 707                        "comedi: attempted to read-free more bytes than have been read-allocated.\n");
 708                 nbytes = async->buf_read_alloc_count - async->buf_read_count;
 709         }
 710         async->buf_read_count += nbytes;
 711         async->buf_read_ptr += nbytes;
 712         async->buf_read_ptr %= async->prealloc_bufsz;
 713         return nbytes;
 714 }
 715 EXPORT_SYMBOL(comedi_buf_read_free);
 716
 717 void comedi_buf_memcpy_to(struct comedi_async *async, unsigned int offset,
 718                           const void *data, unsigned int num_bytes)
 719 {
 720         unsigned int write_ptr = async->buf_write_ptr + offset;
 721
 722         if (write_ptr >= async->prealloc_bufsz)
 723                 write_ptr %= async->prealloc_bufsz;
 724
 725         while (num_bytes) {
 726                 unsigned int block_size;
 727
 728                 if (write_ptr + num_bytes > async->prealloc_bufsz)
 729                         block_size = async->prealloc_bufsz - write_ptr;
 730                 else
 731                         block_size = num_bytes;
 732
 733                 memcpy(async->prealloc_buf + write_ptr, data, block_size);
 734
 735                 data += block_size;
 736                 num_bytes -= block_size;
 737
 738                 write_ptr = 0;
 739         }
 740 }
 741 EXPORT_SYMBOL(comedi_buf_memcpy_to);
 742
 743 void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset,
 744                             void *dest, unsigned int nbytes)
 745 {
 746         void *src;
 747         unsigned int read_ptr = async->buf_read_ptr + offset;
 748
 749         if (read_ptr >= async->prealloc_bufsz)
 750                 read_ptr %= async->prealloc_bufsz;
 751
 752         while (nbytes) {
 753                 unsigned int block_size;
 754
 755                 src = async->prealloc_buf + read_ptr;
 756
 757                 if (nbytes >= async->prealloc_bufsz - read_ptr)
 758                         block_size = async->prealloc_bufsz - read_ptr;
 759                 else
 760                         block_size = nbytes;
 761
 762                 memcpy(dest, src, block_size);
 763                 nbytes -= block_size;
 764                 dest += block_size;
 765                 read_ptr = 0;
 766         }
 767 }
 768 EXPORT_SYMBOL(comedi_buf_memcpy_from);
 769
 770 unsigned int comedi_buf_read_n_available(struct comedi_async *async)
 771 {
 772         unsigned num_bytes;
 773
 774         if (async == NULL)
 775                 return 0;
 776         num_bytes = async->munge_count - async->buf_read_count;
 777         /* barrier insures the read of munge_count in this
 778            query occurs before any following reads of the buffer which
 779            might be based on the return value from this query.
 780          */
 781         smp_rmb();
 782         return num_bytes;
 783 }
 784 EXPORT_SYMBOL(comedi_buf_read_n_available);
 785
 786 int comedi_buf_get(struct comedi_async *async, short *x)
 787 {
 788         unsigned int n = comedi_buf_read_n_available(async);
 789
 790         if (n < sizeof(short))
 791                 return 0;
 792         comedi_buf_read_alloc(async, sizeof(short));
 793         *x = *(short *)(async->prealloc_buf + async->buf_read_ptr);
 794         comedi_buf_read_free(async, sizeof(short));
 795         return 1;
 796 }
 797 EXPORT_SYMBOL(comedi_buf_get);
 798
 799 int comedi_buf_put(struct comedi_async *async, short x)
 800 {
 801         unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(short));
 802
 803         if (n < sizeof(short)) {
 804                 async->events |= COMEDI_CB_ERROR;
 805                 return 0;
 806         }
 807         *(short *)(async->prealloc_buf + async->buf_write_ptr) = x;
 808         comedi_buf_write_free(async, sizeof(short));
 809         return 1;
 810 }
 811 EXPORT_SYMBOL(comedi_buf_put);
 812
 813 void comedi_reset_async_buf(struct comedi_async *async)
 814 {
 815         async->buf_write_alloc_count = 0;
 816         async->buf_write_count = 0;
 817         async->buf_read_alloc_count = 0;
 818         async->buf_read_count = 0;
 819
 820         async->buf_write_ptr = 0;
 821         async->buf_read_ptr = 0;
 822
 823         async->cur_chan = 0;
 824         async->scan_progress = 0;
 825         async->munge_chan = 0;
 826         async->munge_count = 0;
 827         async->munge_ptr = 0;
 828
 829         async->events = 0;
 830 }
 831
 832 static int
 833 comedi_auto_config_helper(struct device *hardware_device,
 834                           struct comedi_driver *driver,
 835                           int (*attach_wrapper) (struct comedi_device *,
 836                                                  void *), void *context)
 837 {
 838         int minor;
 839         struct comedi_device_file_info *dev_file_info;
 840         struct comedi_device *comedi_dev;
 841         int ret;
 842
 843         if (!comedi_autoconfig)
 844                 return 0;
 845
 846         minor = comedi_alloc_board_minor(hardware_device);
 847         if (minor < 0)
 848                 return minor;
 849
 850         dev_file_info = comedi_get_device_file_info(minor);
 851         comedi_dev = dev_file_info->device;
 852
 853         mutex_lock(&comedi_dev->mutex);
 854         if (comedi_dev->attached)
 855                 ret = -EBUSY;
 856         else if (!try_module_get(driver->module)) {
 857                 printk(KERN_INFO "comedi: failed to increment module count\n");
 858                 ret = -EIO;
 859         } else {
 860                 /* set comedi_dev->driver here for attach wrapper */
 861                 comedi_dev->driver = driver;
 862                 ret = (*attach_wrapper)(comedi_dev, context);
 863                 if (ret < 0) {
 864                         module_put(driver->module);
 865                         __comedi_device_detach(comedi_dev);
 866                 } else {
 867                         ret = comedi_device_postconfig(comedi_dev);
 868                 }
 869         }
 870         mutex_unlock(&comedi_dev->mutex);
 871
 872         if (ret < 0)
 873                 comedi_free_board_minor(minor);
 874         return ret;
 875 }
 876
 877 static int comedi_auto_config_wrapper(struct comedi_device *dev, void *context)
 878 {
 879         struct comedi_devconfig *it = context;
 880         struct comedi_driver *driv = dev->driver;
 881
 882         if (driv->num_names) {
 883                 /* look for generic board entry matching driver name, which
 884                  * has already been copied to it->board_name */
 885                 dev->board_ptr = comedi_recognize(driv, it->board_name);
 886                 if (dev->board_ptr == NULL) {
 887                         printk(KERN_WARNING
 888                                "comedi: auto config failed to find board entry"
 889                                " '%s' for driver '%s'\n", it->board_name,
 890                                driv->driver_name);
 891                         comedi_report_boards(driv);
 892                         return -EINVAL;
 893                 }
 894         }
 895         return driv->attach(dev, it);
 896 }
 897
 898 static int comedi_auto_config(struct device *hardware_device,
 899                               struct comedi_driver *driver, const int *options,
 900                               unsigned num_options)
 901 {
 902         struct comedi_devconfig it;
 903
 904         memset(&it, 0, sizeof(it));
 905         strncpy(it.board_name, driver->driver_name, COMEDI_NAMELEN);
 906         it.board_name[COMEDI_NAMELEN - 1] = '\0';
 907         BUG_ON(num_options > COMEDI_NDEVCONFOPTS);
 908         memcpy(it.options, options, num_options * sizeof(int));
 909         return comedi_auto_config_helper(hardware_device, driver,
 910                                          comedi_auto_config_wrapper, &it);
 911 }
 912
 913 static void comedi_auto_unconfig(struct device *hardware_device)
 914 {
 915         int minor;
 916
 917         if (hardware_device == NULL)
 918                 return;
 919         minor = comedi_find_board_minor(hardware_device);
 920         if (minor < 0)
 921                 return;
 922         BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
 923         comedi_free_board_minor(minor);
 924 }
 925
 926 /**
 927  * comedi_pci_enable() - Enable the PCI device and request the regions.
 928  * @pdev: pci_dev struct
 929  * @res_name: name for the requested reqource
 930  */
 931 int comedi_pci_enable(struct pci_dev *pdev, const char *res_name)
 932 {
 933         int rc;
 934
 935         rc = pci_enable_device(pdev);
 936         if (rc < 0)
 937                 return rc;
 938
 939         rc = pci_request_regions(pdev, res_name);
 940         if (rc < 0)
 941                 pci_disable_device(pdev);
 942
 943         return rc;
 944 }
 945 EXPORT_SYMBOL_GPL(comedi_pci_enable);
 946
 947 /**
 948  * comedi_pci_disable() - Release the regions and disable the PCI device.
 949  * @pdev: pci_dev struct
 950  *
 951  * This must be matched with a previous successful call to comedi_pci_enable().
 952  */
 953 void comedi_pci_disable(struct pci_dev *pdev)
 954 {
 955         pci_release_regions(pdev);
 956         pci_disable_device(pdev);
 957 }
 958 EXPORT_SYMBOL_GPL(comedi_pci_disable);
 959
 960 static int comedi_old_pci_auto_config(struct pci_dev *pcidev,
 961                                       struct comedi_driver *driver)
 962 {
 963         int options[2];
 964
 965         /*  pci bus */
 966         options[0] = pcidev->bus->number;
 967         /*  pci slot */
 968         options[1] = PCI_SLOT(pcidev->devfn);
 969
 970         return comedi_auto_config(&pcidev->dev, driver,
 971                                   options, ARRAY_SIZE(options));
 972 }
 973
 974 static int comedi_pci_attach_wrapper(struct comedi_device *dev, void *pcidev)
 975 {
 976         return dev->driver->attach_pci(dev, pcidev);
 977 }
 978
 979 static int comedi_new_pci_auto_config(struct pci_dev *pcidev,
 980                                       struct comedi_driver *driver)
 981 {
 982         return comedi_auto_config_helper(&pcidev->dev, driver,
 983                                          comedi_pci_attach_wrapper, pcidev);
 984 }
 985
 986 int comedi_pci_auto_config(struct pci_dev *pcidev, struct comedi_driver *driver)
 987 {
 988
 989         if (driver->attach_pci)
 990                 return comedi_new_pci_auto_config(pcidev, driver);
 991         else
 992                 return comedi_old_pci_auto_config(pcidev, driver);
 993 }
 994 EXPORT_SYMBOL_GPL(comedi_pci_auto_config);
 995
 996 void comedi_pci_auto_unconfig(struct pci_dev *pcidev)
 997 {
 998         comedi_auto_unconfig(&pcidev->dev);
 999 }
1000 EXPORT_SYMBOL_GPL(comedi_pci_auto_unconfig);
1001
1002 int comedi_pci_driver_register(struct comedi_driver *comedi_driver,
1003                 struct pci_driver *pci_driver)
1004 {
1005         int ret;
1006
1007         ret = comedi_driver_register(comedi_driver);
1008         if (ret < 0)
1009                 return ret;
1010
1011         /* FIXME: Remove this test after auditing all comedi pci drivers */
1012         if (!pci_driver->name)
1013                 pci_driver->name = comedi_driver->driver_name;
1014
1015         ret = pci_register_driver(pci_driver);
1016         if (ret < 0) {
1017                 comedi_driver_unregister(comedi_driver);
1018                 return ret;
1019         }
1020
1021         return 0;
1022 }
1023 EXPORT_SYMBOL_GPL(comedi_pci_driver_register);
1024
1025 void comedi_pci_driver_unregister(struct comedi_driver *comedi_driver,
1026                 struct pci_driver *pci_driver)
1027 {
1028         pci_unregister_driver(pci_driver);
1029         comedi_driver_unregister(comedi_driver);
1030 }
1031 EXPORT_SYMBOL_GPL(comedi_pci_driver_unregister);
1032
1033 #if IS_ENABLED(CONFIG_USB)
1034
1035 static int comedi_old_usb_auto_config(struct usb_interface *intf,
1036                                       struct comedi_driver *driver)
1037 {
1038         return comedi_auto_config(&intf->dev, driver, NULL, 0);
1039 }
1040
1041 static int comedi_usb_attach_wrapper(struct comedi_device *dev, void *intf)
1042 {
1043         return dev->driver->attach_usb(dev, intf);
1044 }
1045
1046 static int comedi_new_usb_auto_config(struct usb_interface *intf,
1047                                       struct comedi_driver *driver)
1048 {
1049         return comedi_auto_config_helper(&intf->dev, driver,
1050                                          comedi_usb_attach_wrapper, intf);
1051 }
1052
1053 int comedi_usb_auto_config(struct usb_interface *intf,
1054                            struct comedi_driver *driver)
1055 {
1056         BUG_ON(intf == NULL);
1057         if (driver->attach_usb)
1058                 return comedi_new_usb_auto_config(intf, driver);
1059         else
1060                 return comedi_old_usb_auto_config(intf, driver);
1061 }
1062 EXPORT_SYMBOL_GPL(comedi_usb_auto_config);
1063
1064 void comedi_usb_auto_unconfig(struct usb_interface *intf)
1065 {
1066         BUG_ON(intf == NULL);
1067         comedi_auto_unconfig(&intf->dev);
1068 }
1069 EXPORT_SYMBOL_GPL(comedi_usb_auto_unconfig);
1070
1071 int comedi_usb_driver_register(struct comedi_driver *comedi_driver,
1072                 struct usb_driver *usb_driver)
1073 {
1074         int ret;
1075
1076         ret = comedi_driver_register(comedi_driver);
1077         if (ret < 0)
1078                 return ret;
1079
1080         ret = usb_register(usb_driver);
1081         if (ret < 0) {
1082                 comedi_driver_unregister(comedi_driver);
1083                 return ret;
1084         }
1085
1086         return 0;
1087 }
1088 EXPORT_SYMBOL_GPL(comedi_usb_driver_register);
1089
1090 void comedi_usb_driver_unregister(struct comedi_driver *comedi_driver,
1091                 struct usb_driver *usb_driver)
1092 {
1093         usb_deregister(usb_driver);
1094         comedi_driver_unregister(comedi_driver);
1095 }
1096 EXPORT_SYMBOL_GPL(comedi_usb_driver_unregister);
1097
1098 #endif