linux/drivers/staging/comedi/drivers.c
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   1/*
   2    module/drivers.c
   3    functions for manipulating drivers
   4
   5    COMEDI - Linux Control and Measurement Device Interface
   6    Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21
  22*/
  23
  24#define _GNU_SOURCE
  25
  26#define __NO_VERSION__
  27#include "comedi_fops.h"
  28#include <linux/device.h>
  29#include <linux/module.h>
  30#include <linux/pci.h>
  31#include <linux/usb.h>
  32#include <linux/errno.h>
  33#include <linux/kernel.h>
  34#include <linux/sched.h>
  35#include <linux/fcntl.h>
  36#include <linux/delay.h>
  37#include <linux/ioport.h>
  38#include <linux/mm.h>
  39#include <linux/slab.h>
  40#include "comedidev.h"
  41#include "wrapper.h"
  42#include <linux/highmem.h>      /* for SuSE brokenness */
  43#include <linux/vmalloc.h>
  44#include <linux/cdev.h>
  45#include <linux/dma-mapping.h>
  46
  47#include <asm/io.h>
  48#include <asm/system.h>
  49
  50static int postconfig(struct comedi_device *dev);
  51static int insn_rw_emulate_bits(struct comedi_device *dev,
  52                                struct comedi_subdevice *s,
  53                                struct comedi_insn *insn, unsigned int *data);
  54static void *comedi_recognize(struct comedi_driver *driv, const char *name);
  55static void comedi_report_boards(struct comedi_driver *driv);
  56static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s);
  57int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
  58                     unsigned long new_size);
  59
  60struct comedi_driver *comedi_drivers;
  61
  62int comedi_modprobe(int minor)
  63{
  64        return -EINVAL;
  65}
  66
  67static void cleanup_device(struct comedi_device *dev)
  68{
  69        int i;
  70        struct comedi_subdevice *s;
  71
  72        if (dev->subdevices) {
  73                for (i = 0; i < dev->n_subdevices; i++) {
  74                        s = dev->subdevices + i;
  75                        comedi_free_subdevice_minor(s);
  76                        if (s->async) {
  77                                comedi_buf_alloc(dev, s, 0);
  78                                kfree(s->async);
  79                        }
  80                }
  81                kfree(dev->subdevices);
  82                dev->subdevices = NULL;
  83                dev->n_subdevices = 0;
  84        }
  85        kfree(dev->private);
  86        dev->private = NULL;
  87        dev->driver = 0;
  88        dev->board_name = NULL;
  89        dev->board_ptr = NULL;
  90        dev->iobase = 0;
  91        dev->irq = 0;
  92        dev->read_subdev = NULL;
  93        dev->write_subdev = NULL;
  94        dev->open = NULL;
  95        dev->close = NULL;
  96        comedi_set_hw_dev(dev, NULL);
  97}
  98
  99static void __comedi_device_detach(struct comedi_device *dev)
 100{
 101        dev->attached = 0;
 102        if (dev->driver) {
 103                dev->driver->detach(dev);
 104        } else {
 105                printk("BUG: dev->driver=NULL in comedi_device_detach()\n");
 106        }
 107        cleanup_device(dev);
 108}
 109
 110void comedi_device_detach(struct comedi_device *dev)
 111{
 112        if (!dev->attached)
 113                return;
 114        __comedi_device_detach(dev);
 115}
 116
 117int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 118{
 119        struct comedi_driver *driv;
 120        int ret;
 121
 122        if (dev->attached)
 123                return -EBUSY;
 124
 125        for (driv = comedi_drivers; driv; driv = driv->next) {
 126                if (!try_module_get(driv->module)) {
 127                        printk
 128                            ("comedi: failed to increment module count, skipping\n");
 129                        continue;
 130                }
 131                if (driv->num_names) {
 132                        dev->board_ptr = comedi_recognize(driv, it->board_name);
 133                        if (dev->board_ptr == NULL) {
 134                                module_put(driv->module);
 135                                continue;
 136                        }
 137                } else {
 138                        if (strcmp(driv->driver_name, it->board_name)) {
 139                                module_put(driv->module);
 140                                continue;
 141                        }
 142                }
 143                /* initialize dev->driver here so comedi_error() can be called from attach */
 144                dev->driver = driv;
 145                ret = driv->attach(dev, it);
 146                if (ret < 0) {
 147                        module_put(dev->driver->module);
 148                        __comedi_device_detach(dev);
 149                        return ret;
 150                }
 151                goto attached;
 152        }
 153
 154        /*  recognize has failed if we get here */
 155        /*  report valid board names before returning error */
 156        for (driv = comedi_drivers; driv; driv = driv->next) {
 157                if (!try_module_get(driv->module)) {
 158                        printk("comedi: failed to increment module count\n");
 159                        continue;
 160                }
 161                comedi_report_boards(driv);
 162                module_put(driv->module);
 163        }
 164        return -EIO;
 165
 166attached:
 167        /* do a little post-config cleanup */
 168        ret = postconfig(dev);
 169        module_put(dev->driver->module);
 170        if (ret < 0) {
 171                __comedi_device_detach(dev);
 172                return ret;
 173        }
 174
 175        if (!dev->board_name) {
 176                printk("BUG: dev->board_name=<%p>\n", dev->board_name);
 177                dev->board_name = "BUG";
 178        }
 179        smp_wmb();
 180        dev->attached = 1;
 181
 182        return 0;
 183}
 184
 185int comedi_driver_register(struct comedi_driver *driver)
 186{
 187        driver->next = comedi_drivers;
 188        comedi_drivers = driver;
 189
 190        return 0;
 191}
 192
 193int comedi_driver_unregister(struct comedi_driver *driver)
 194{
 195        struct comedi_driver *prev;
 196        int i;
 197
 198        /* check for devices using this driver */
 199        for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
 200                struct comedi_device_file_info *dev_file_info =
 201                    comedi_get_device_file_info(i);
 202                struct comedi_device *dev;
 203
 204                if (dev_file_info == NULL)
 205                        continue;
 206                dev = dev_file_info->device;
 207
 208                mutex_lock(&dev->mutex);
 209                if (dev->attached && dev->driver == driver) {
 210                        if (dev->use_count)
 211                                printk
 212                                    ("BUG! detaching device with use_count=%d\n",
 213                                     dev->use_count);
 214                        comedi_device_detach(dev);
 215                }
 216                mutex_unlock(&dev->mutex);
 217        }
 218
 219        if (comedi_drivers == driver) {
 220                comedi_drivers = driver->next;
 221                return 0;
 222        }
 223
 224        for (prev = comedi_drivers; prev->next; prev = prev->next) {
 225                if (prev->next == driver) {
 226                        prev->next = driver->next;
 227                        return 0;
 228                }
 229        }
 230        return -EINVAL;
 231}
 232
 233static int postconfig(struct comedi_device *dev)
 234{
 235        int i;
 236        struct comedi_subdevice *s;
 237        struct comedi_async *async = NULL;
 238        int ret;
 239
 240        for (i = 0; i < dev->n_subdevices; i++) {
 241                s = dev->subdevices + i;
 242
 243                if (s->type == COMEDI_SUBD_UNUSED)
 244                        continue;
 245
 246                if (s->len_chanlist == 0)
 247                        s->len_chanlist = 1;
 248
 249                if (s->do_cmd) {
 250                        BUG_ON((s->subdev_flags & (SDF_CMD_READ |
 251                                                   SDF_CMD_WRITE)) == 0);
 252                        BUG_ON(!s->do_cmdtest);
 253
 254                        async =
 255                            kzalloc(sizeof(struct comedi_async), GFP_KERNEL);
 256                        if (async == NULL) {
 257                                printk("failed to allocate async struct\n");
 258                                return -ENOMEM;
 259                        }
 260                        init_waitqueue_head(&async->wait_head);
 261                        async->subdevice = s;
 262                        s->async = async;
 263
 264#define DEFAULT_BUF_MAXSIZE (64*1024)
 265#define DEFAULT_BUF_SIZE (64*1024)
 266
 267                        async->max_bufsize = DEFAULT_BUF_MAXSIZE;
 268
 269                        async->prealloc_buf = NULL;
 270                        async->prealloc_bufsz = 0;
 271                        if (comedi_buf_alloc(dev, s, DEFAULT_BUF_SIZE) < 0) {
 272                                printk("Buffer allocation failed\n");
 273                                return -ENOMEM;
 274                        }
 275                        if (s->buf_change) {
 276                                ret = s->buf_change(dev, s, DEFAULT_BUF_SIZE);
 277                                if (ret < 0)
 278                                        return ret;
 279                        }
 280                        comedi_alloc_subdevice_minor(dev, s);
 281                }
 282
 283                if (!s->range_table && !s->range_table_list)
 284                        s->range_table = &range_unknown;
 285
 286                if (!s->insn_read && s->insn_bits)
 287                        s->insn_read = insn_rw_emulate_bits;
 288                if (!s->insn_write && s->insn_bits)
 289                        s->insn_write = insn_rw_emulate_bits;
 290
 291                if (!s->insn_read)
 292                        s->insn_read = insn_inval;
 293                if (!s->insn_write)
 294                        s->insn_write = insn_inval;
 295                if (!s->insn_bits)
 296                        s->insn_bits = insn_inval;
 297                if (!s->insn_config)
 298                        s->insn_config = insn_inval;
 299
 300                if (!s->poll)
 301                        s->poll = poll_invalid;
 302        }
 303
 304        return 0;
 305}
 306
 307/*  generic recognize function for drivers that register their supported board names */
 308void *comedi_recognize(struct comedi_driver *driv, const char *name)
 309{
 310        unsigned i;
 311        const char *const *name_ptr = driv->board_name;
 312        for (i = 0; i < driv->num_names; i++) {
 313                if (strcmp(*name_ptr, name) == 0)
 314                        return (void *)name_ptr;
 315                name_ptr =
 316                    (const char *const *)((const char *)name_ptr +
 317                                          driv->offset);
 318        }
 319
 320        return NULL;
 321}
 322
 323void comedi_report_boards(struct comedi_driver *driv)
 324{
 325        unsigned int i;
 326        const char *const *name_ptr;
 327
 328        printk("comedi: valid board names for %s driver are:\n",
 329               driv->driver_name);
 330
 331        name_ptr = driv->board_name;
 332        for (i = 0; i < driv->num_names; i++) {
 333                printk(" %s\n", *name_ptr);
 334                name_ptr = (const char **)((char *)name_ptr + driv->offset);
 335        }
 336
 337        if (driv->num_names == 0)
 338                printk(" %s\n", driv->driver_name);
 339}
 340
 341static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
 342{
 343        return -EINVAL;
 344}
 345
 346int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
 347               struct comedi_insn *insn, unsigned int *data)
 348{
 349        return -EINVAL;
 350}
 351
 352static int insn_rw_emulate_bits(struct comedi_device *dev,
 353                                struct comedi_subdevice *s,
 354                                struct comedi_insn *insn, unsigned int *data)
 355{
 356        struct comedi_insn new_insn;
 357        int ret;
 358        static const unsigned channels_per_bitfield = 32;
 359
 360        unsigned chan = CR_CHAN(insn->chanspec);
 361        const unsigned base_bitfield_channel =
 362            (chan < channels_per_bitfield) ? 0 : chan;
 363        unsigned int new_data[2];
 364        memset(new_data, 0, sizeof(new_data));
 365        memset(&new_insn, 0, sizeof(new_insn));
 366        new_insn.insn = INSN_BITS;
 367        new_insn.chanspec = base_bitfield_channel;
 368        new_insn.n = 2;
 369        new_insn.data = new_data;
 370        new_insn.subdev = insn->subdev;
 371
 372        if (insn->insn == INSN_WRITE) {
 373                if (!(s->subdev_flags & SDF_WRITABLE))
 374                        return -EINVAL;
 375                new_data[0] = 1 << (chan - base_bitfield_channel);      /* mask */
 376                new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel)) : 0;      /* bits */
 377        }
 378
 379        ret = s->insn_bits(dev, s, &new_insn, new_data);
 380        if (ret < 0)
 381                return ret;
 382
 383        if (insn->insn == INSN_READ) {
 384                data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
 385        }
 386
 387        return 1;
 388}
 389
 390static inline unsigned long uvirt_to_kva(pgd_t * pgd, unsigned long adr)
 391{
 392        unsigned long ret = 0UL;
 393        pmd_t *pmd;
 394        pte_t *ptep, pte;
 395        pud_t *pud;
 396
 397        if (!pgd_none(*pgd)) {
 398                pud = pud_offset(pgd, adr);
 399                pmd = pmd_offset(pud, adr);
 400                if (!pmd_none(*pmd)) {
 401                        ptep = pte_offset_kernel(pmd, adr);
 402                        pte = *ptep;
 403                        if (pte_present(pte)) {
 404                                ret = (unsigned long)
 405                                    page_address(pte_page(pte));
 406                                ret |= (adr & (PAGE_SIZE - 1));
 407                        }
 408                }
 409        }
 410        return ret;
 411}
 412
 413static inline unsigned long kvirt_to_kva(unsigned long adr)
 414{
 415        unsigned long va, kva;
 416
 417        va = adr;
 418        kva = uvirt_to_kva(pgd_offset_k(va), va);
 419
 420        return kva;
 421}
 422
 423int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
 424                     unsigned long new_size)
 425{
 426        struct comedi_async *async = s->async;
 427
 428        /* Round up new_size to multiple of PAGE_SIZE */
 429        new_size = (new_size + PAGE_SIZE - 1) & PAGE_MASK;
 430
 431        /* if no change is required, do nothing */
 432        if (async->prealloc_buf && async->prealloc_bufsz == new_size) {
 433                return 0;
 434        }
 435        /*  deallocate old buffer */
 436        if (async->prealloc_buf) {
 437                vunmap(async->prealloc_buf);
 438                async->prealloc_buf = NULL;
 439                async->prealloc_bufsz = 0;
 440        }
 441        if (async->buf_page_list) {
 442                unsigned i;
 443                for (i = 0; i < async->n_buf_pages; ++i) {
 444                        if (async->buf_page_list[i].virt_addr) {
 445                                mem_map_unreserve(virt_to_page
 446                                                  (async->buf_page_list[i].
 447                                                   virt_addr));
 448                                if (s->async_dma_dir != DMA_NONE) {
 449                                        dma_free_coherent(dev->hw_dev,
 450                                                          PAGE_SIZE,
 451                                                          async->
 452                                                          buf_page_list
 453                                                          [i].virt_addr,
 454                                                          async->
 455                                                          buf_page_list
 456                                                          [i].dma_addr);
 457                                } else {
 458                                        free_page((unsigned long)
 459                                                  async->buf_page_list[i].
 460                                                  virt_addr);
 461                                }
 462                        }
 463                }
 464                vfree(async->buf_page_list);
 465                async->buf_page_list = NULL;
 466                async->n_buf_pages = 0;
 467        }
 468        /*  allocate new buffer */
 469        if (new_size) {
 470                unsigned i = 0;
 471                unsigned n_pages = new_size >> PAGE_SHIFT;
 472                struct page **pages = NULL;
 473
 474                async->buf_page_list =
 475                    vmalloc(sizeof(struct comedi_buf_page) * n_pages);
 476                if (async->buf_page_list) {
 477                        memset(async->buf_page_list, 0,
 478                               sizeof(struct comedi_buf_page) * n_pages);
 479                        pages = vmalloc(sizeof(struct page *) * n_pages);
 480                }
 481                if (pages) {
 482                        for (i = 0; i < n_pages; i++) {
 483                                if (s->async_dma_dir != DMA_NONE) {
 484                                        async->buf_page_list[i].virt_addr =
 485                                            dma_alloc_coherent(dev->hw_dev,
 486                                                               PAGE_SIZE,
 487                                                               &async->
 488                                                               buf_page_list
 489                                                               [i].dma_addr,
 490                                                               GFP_KERNEL |
 491                                                               __GFP_COMP);
 492                                } else {
 493                                        async->buf_page_list[i].virt_addr =
 494                                            (void *)
 495                                            get_zeroed_page(GFP_KERNEL);
 496                                }
 497                                if (async->buf_page_list[i].virt_addr == NULL) {
 498                                        break;
 499                                }
 500                                mem_map_reserve(virt_to_page
 501                                                (async->buf_page_list[i].
 502                                                 virt_addr));
 503                                pages[i] =
 504                                    virt_to_page(async->
 505                                                 buf_page_list[i].virt_addr);
 506                        }
 507                }
 508                if (i == n_pages) {
 509                        async->prealloc_buf =
 510                            vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
 511                }
 512                vfree(pages);
 513
 514                if (async->prealloc_buf == NULL) {
 515                        /* Some allocation failed above. */
 516                        if (async->buf_page_list) {
 517                                for (i = 0; i < n_pages; i++) {
 518                                        if (async->buf_page_list[i].virt_addr ==
 519                                            NULL) {
 520                                                break;
 521                                        }
 522                                        mem_map_unreserve(virt_to_page
 523                                                          (async->buf_page_list
 524                                                           [i].virt_addr));
 525                                        if (s->async_dma_dir != DMA_NONE) {
 526                                                dma_free_coherent(dev->hw_dev,
 527                                                                  PAGE_SIZE,
 528                                                                  async->
 529                                                                  buf_page_list
 530                                                                  [i].virt_addr,
 531                                                                  async->
 532                                                                  buf_page_list
 533                                                                  [i].dma_addr);
 534                                        } else {
 535                                                free_page((unsigned long)
 536                                                          async->buf_page_list
 537                                                          [i].virt_addr);
 538                                        }
 539                                }
 540                                vfree(async->buf_page_list);
 541                                async->buf_page_list = NULL;
 542                        }
 543                        return -ENOMEM;
 544                }
 545                async->n_buf_pages = n_pages;
 546        }
 547        async->prealloc_bufsz = new_size;
 548
 549        return 0;
 550}
 551
 552/* munging is applied to data by core as it passes between user
 553 * and kernel space */
 554unsigned int comedi_buf_munge(struct comedi_async *async,
 555                              unsigned int num_bytes)
 556{
 557        struct comedi_subdevice *s = async->subdevice;
 558        unsigned int count = 0;
 559        const unsigned num_sample_bytes = bytes_per_sample(s);
 560
 561        if (s->munge == NULL || (async->cmd.flags & CMDF_RAWDATA)) {
 562                async->munge_count += num_bytes;
 563                BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
 564                return num_bytes;
 565        }
 566        /* don't munge partial samples */
 567        num_bytes -= num_bytes % num_sample_bytes;
 568        while (count < num_bytes) {
 569                int block_size;
 570
 571                block_size = num_bytes - count;
 572                if (block_size < 0) {
 573                        printk("%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 before munge_count is incremented */
 585
 586                async->munge_chan += block_size / num_sample_bytes;
 587                async->munge_chan %= async->cmd.chanlist_len;
 588                async->munge_count += block_size;
 589                async->munge_ptr += block_size;
 590                async->munge_ptr %= async->prealloc_bufsz;
 591                count += block_size;
 592        }
 593        BUG_ON((int)(async->munge_count - async->buf_write_count) > 0);
 594        return count;
 595}
 596
 597unsigned int comedi_buf_write_n_available(struct comedi_async *async)
 598{
 599        unsigned int free_end;
 600        unsigned int nbytes;
 601
 602        if (async == NULL)
 603                return 0;
 604
 605        free_end = async->buf_read_count + async->prealloc_bufsz;
 606        nbytes = free_end - async->buf_write_alloc_count;
 607        nbytes -= nbytes % bytes_per_sample(async->subdevice);
 608        /* barrier insures the read of buf_read_count in this
 609           query occurs before any following writes to the buffer which
 610           might be based on the return value from this query.
 611         */
 612        smp_mb();
 613        return nbytes;
 614}
 615
 616/* allocates chunk for the writer from free buffer space */
 617unsigned int comedi_buf_write_alloc(struct comedi_async *async,
 618                                    unsigned int nbytes)
 619{
 620        unsigned int free_end = async->buf_read_count + async->prealloc_bufsz;
 621
 622        if ((int)(async->buf_write_alloc_count + nbytes - free_end) > 0) {
 623                nbytes = free_end - async->buf_write_alloc_count;
 624        }
 625        async->buf_write_alloc_count += nbytes;
 626        /* barrier insures the read of buf_read_count above occurs before
 627           we write data to the write-alloc'ed buffer space */
 628        smp_mb();
 629        return nbytes;
 630}
 631
 632/* allocates nothing unless it can completely fulfill the request */
 633unsigned int comedi_buf_write_alloc_strict(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 = 0;
 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
 648/* transfers a chunk from writer to filled buffer space */
 649unsigned comedi_buf_write_free(struct comedi_async *async, unsigned int nbytes)
 650{
 651        if ((int)(async->buf_write_count + nbytes -
 652                  async->buf_write_alloc_count) > 0) {
 653                printk
 654                    ("comedi: attempted to write-free more bytes than have been write-allocated.\n");
 655                nbytes = async->buf_write_alloc_count - async->buf_write_count;
 656        }
 657        async->buf_write_count += nbytes;
 658        async->buf_write_ptr += nbytes;
 659        comedi_buf_munge(async, async->buf_write_count - async->munge_count);
 660        if (async->buf_write_ptr >= async->prealloc_bufsz) {
 661                async->buf_write_ptr %= async->prealloc_bufsz;
 662        }
 663        return nbytes;
 664}
 665
 666/* allocates a chunk for the reader from filled (and munged) buffer space */
 667unsigned comedi_buf_read_alloc(struct comedi_async *async, unsigned nbytes)
 668{
 669        if ((int)(async->buf_read_alloc_count + nbytes - async->munge_count) >
 670            0) {
 671                nbytes = async->munge_count - async->buf_read_alloc_count;
 672        }
 673        async->buf_read_alloc_count += nbytes;
 674        /* barrier insures read of munge_count occurs before we actually read
 675           data out of buffer */
 676        smp_rmb();
 677        return nbytes;
 678}
 679
 680/* transfers control of a chunk from reader to free buffer space */
 681unsigned comedi_buf_read_free(struct comedi_async *async, unsigned int nbytes)
 682{
 683        /*  barrier insures data has been read out of buffer before read count is incremented */
 684        smp_mb();
 685        if ((int)(async->buf_read_count + nbytes -
 686                  async->buf_read_alloc_count) > 0) {
 687                printk
 688                    ("comedi: attempted to read-free more bytes than have been read-allocated.\n");
 689                nbytes = async->buf_read_alloc_count - async->buf_read_count;
 690        }
 691        async->buf_read_count += nbytes;
 692        async->buf_read_ptr += nbytes;
 693        async->buf_read_ptr %= async->prealloc_bufsz;
 694        return nbytes;
 695}
 696
 697void comedi_buf_memcpy_to(struct comedi_async *async, unsigned int offset,
 698                          const void *data, unsigned int num_bytes)
 699{
 700        unsigned int write_ptr = async->buf_write_ptr + offset;
 701
 702        if (write_ptr >= async->prealloc_bufsz)
 703                write_ptr %= async->prealloc_bufsz;
 704
 705        while (num_bytes) {
 706                unsigned int block_size;
 707
 708                if (write_ptr + num_bytes > async->prealloc_bufsz)
 709                        block_size = async->prealloc_bufsz - write_ptr;
 710                else
 711                        block_size = num_bytes;
 712
 713                memcpy(async->prealloc_buf + write_ptr, data, block_size);
 714
 715                data += block_size;
 716                num_bytes -= block_size;
 717
 718                write_ptr = 0;
 719        }
 720}
 721
 722void comedi_buf_memcpy_from(struct comedi_async *async, unsigned int offset,
 723                            void *dest, unsigned int nbytes)
 724{
 725        void *src;
 726        unsigned int read_ptr = async->buf_read_ptr + offset;
 727
 728        if (read_ptr >= async->prealloc_bufsz)
 729                read_ptr %= async->prealloc_bufsz;
 730
 731        while (nbytes) {
 732                unsigned int block_size;
 733
 734                src = async->prealloc_buf + read_ptr;
 735
 736                if (nbytes >= async->prealloc_bufsz - read_ptr)
 737                        block_size = async->prealloc_bufsz - read_ptr;
 738                else
 739                        block_size = nbytes;
 740
 741                memcpy(dest, src, block_size);
 742                nbytes -= block_size;
 743                dest += block_size;
 744                read_ptr = 0;
 745        }
 746}
 747
 748unsigned int comedi_buf_read_n_available(struct comedi_async *async)
 749{
 750        unsigned num_bytes;
 751
 752        if (async == NULL)
 753                return 0;
 754        num_bytes = async->munge_count - async->buf_read_count;
 755        /* barrier insures the read of munge_count in this
 756           query occurs before any following reads of the buffer which
 757           might be based on the return value from this query.
 758         */
 759        smp_rmb();
 760        return num_bytes;
 761}
 762
 763int comedi_buf_get(struct comedi_async *async, short *x)
 764{
 765        unsigned int n = comedi_buf_read_n_available(async);
 766
 767        if (n < sizeof(short))
 768                return 0;
 769        comedi_buf_read_alloc(async, sizeof(short));
 770        *x = *(short *)(async->prealloc_buf + async->buf_read_ptr);
 771        comedi_buf_read_free(async, sizeof(short));
 772        return 1;
 773}
 774
 775int comedi_buf_put(struct comedi_async *async, short x)
 776{
 777        unsigned int n = comedi_buf_write_alloc_strict(async, sizeof(short));
 778
 779        if (n < sizeof(short)) {
 780                async->events |= COMEDI_CB_ERROR;
 781                return 0;
 782        }
 783        *(short *)(async->prealloc_buf + async->buf_write_ptr) = x;
 784        comedi_buf_write_free(async, sizeof(short));
 785        return 1;
 786}
 787
 788void comedi_reset_async_buf(struct comedi_async *async)
 789{
 790        async->buf_write_alloc_count = 0;
 791        async->buf_write_count = 0;
 792        async->buf_read_alloc_count = 0;
 793        async->buf_read_count = 0;
 794
 795        async->buf_write_ptr = 0;
 796        async->buf_read_ptr = 0;
 797
 798        async->cur_chan = 0;
 799        async->scan_progress = 0;
 800        async->munge_chan = 0;
 801        async->munge_count = 0;
 802        async->munge_ptr = 0;
 803
 804        async->events = 0;
 805}
 806
 807int comedi_auto_config(struct device *hardware_device, const char *board_name,
 808                       const int *options, unsigned num_options)
 809{
 810        struct comedi_devconfig it;
 811        int minor;
 812        struct comedi_device_file_info *dev_file_info;
 813        int retval;
 814        unsigned *private_data = NULL;
 815
 816        if (!comedi_autoconfig) {
 817                dev_set_drvdata(hardware_device, NULL);
 818                return 0;
 819        }
 820
 821        minor = comedi_alloc_board_minor(hardware_device);
 822        if (minor < 0)
 823                return minor;
 824
 825        private_data = kmalloc(sizeof(unsigned), GFP_KERNEL);
 826        if (private_data == NULL) {
 827                retval = -ENOMEM;
 828                goto cleanup;
 829        }
 830        *private_data = minor;
 831        dev_set_drvdata(hardware_device, private_data);
 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
 845cleanup:
 846        if (retval < 0) {
 847                kfree(private_data);
 848                comedi_free_board_minor(minor);
 849        }
 850        return retval;
 851}
 852
 853void comedi_auto_unconfig(struct device *hardware_device)
 854{
 855        unsigned *minor = (unsigned *)dev_get_drvdata(hardware_device);
 856        if (minor == NULL)
 857                return;
 858
 859        BUG_ON(*minor >= COMEDI_NUM_BOARD_MINORS);
 860
 861        comedi_free_board_minor(*minor);
 862        dev_set_drvdata(hardware_device, NULL);
 863        kfree(minor);
 864}
 865
 866int comedi_pci_auto_config(struct pci_dev *pcidev, const char *board_name)
 867{
 868        int options[2];
 869
 870        /*  pci bus */
 871        options[0] = pcidev->bus->number;
 872        /*  pci slot */
 873        options[1] = PCI_SLOT(pcidev->devfn);
 874
 875        return comedi_auto_config(&pcidev->dev, board_name,
 876                                  options, ARRAY_SIZE(options));
 877}
 878
 879void comedi_pci_auto_unconfig(struct pci_dev *pcidev)
 880{
 881        comedi_auto_unconfig(&pcidev->dev);
 882}
 883
 884int comedi_usb_auto_config(struct usb_device *usbdev, const char *board_name)
 885{
 886        BUG_ON(usbdev == NULL);
 887        return comedi_auto_config(&usbdev->dev, board_name, NULL, 0);
 888}
 889
 890void comedi_usb_auto_unconfig(struct usb_device *usbdev)
 891{
 892        BUG_ON(usbdev == NULL);
 893        comedi_auto_unconfig(&usbdev->dev);
 894}
 895
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