drivers/char/ppdev.c

   1 /*
   2  * linux/drivers/char/ppdev.c
   3  *
   4  * This is the code behind /dev/parport* -- it allows a user-space
   5  * application to use the parport subsystem.
   6  *
   7  * Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version
  12  * 2 of the License, or (at your option) any later version.
  13  *
  14  * A /dev/parportx device node represents an arbitrary device
  15  * on port 'x'.  The following operations are possible:
  16  *
  17  * open         do nothing, set up default IEEE 1284 protocol to be COMPAT
  18  * close        release port and unregister device (if necessary)
  19  * ioctl
  20  *   EXCL       register device exclusively (may fail)
  21  *   CLAIM      (register device first time) parport_claim_or_block
  22  *   RELEASE    parport_release
  23  *   SETMODE    set the IEEE 1284 protocol to use for read/write
  24  *   SETPHASE   set the IEEE 1284 phase of a particular mode.  Not to be
  25  *              confused with ioctl(fd, SETPHASER, &stun). ;-)
  26  *   DATADIR    data_forward / data_reverse
  27  *   WDATA      write_data
  28  *   RDATA      read_data
  29  *   WCONTROL   write_control
  30  *   RCONTROL   read_control
  31  *   FCONTROL   frob_control
  32  *   RSTATUS    read_status
  33  *   NEGOT      parport_negotiate
  34  *   YIELD      parport_yield_blocking
  35  *   WCTLONIRQ  on interrupt, set control lines
  36  *   CLRIRQ     clear (and return) interrupt count
  37  *   SETTIME    sets device timeout (struct timeval)
  38  *   GETTIME    gets device timeout (struct timeval)
  39  *   GETMODES   gets hardware supported modes (unsigned int)
  40  *   GETMODE    gets the current IEEE1284 mode
  41  *   GETPHASE   gets the current IEEE1284 phase
  42  *   GETFLAGS   gets current (user-visible) flags
  43  *   SETFLAGS   sets current (user-visible) flags
  44  * read/write   read or write in current IEEE 1284 protocol
  45  * select       wait for interrupt (in readfds)
  46  *
  47  * Changes:
  48  * Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
  49  *
  50  * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
  51  * - On error, copy_from_user and copy_to_user do not return -EFAULT,
  52  *   They return the positive number of bytes *not* copied due to address
  53  *   space errors.
  54  *
  55  * Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
  56  * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
  57  */
  58
  59 #include <linux/module.h>
  60 #include <linux/init.h>
  61 #include <linux/sched.h>
  62 #include <linux/devfs_fs_kernel.h>
  63 #include <linux/ioctl.h>
  64 #include <linux/parport.h>
  65 #include <linux/ctype.h>
  66 #include <linux/poll.h>
  67 #include <asm/uaccess.h>
  68 #include <linux/ppdev.h>
  69 #include <linux/smp_lock.h>
  70
  71 #define PP_VERSION "ppdev: user-space parallel port driver"
  72 #define CHRDEV "ppdev"
  73
  74 struct pp_struct {
  75         struct pardevice * pdev;
  76         wait_queue_head_t irq_wait;
  77         atomic_t irqc;
  78         unsigned int flags;
  79         int irqresponse;
  80         unsigned char irqctl;
  81         struct ieee1284_info state;
  82         struct ieee1284_info saved_state;
  83         long default_inactivity;
  84 };
  85
  86 /* pp_struct.flags bitfields */
  87 #define PP_CLAIMED    (1<<0)
  88 #define PP_EXCL       (1<<1)
  89
  90 /* Other constants */
  91 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
  92 #define PP_BUFFER_SIZE 1024
  93 #define PARDEVICE_MAX 8
  94
  95 /* ROUND_UP macro from fs/select.c */
  96 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
  97
  98 static inline void pp_enable_irq (struct pp_struct *pp)
  99 {
 100         struct parport *port = pp->pdev->port;
 101         port->ops->enable_irq (port);
 102 }
 103
 104 static ssize_t pp_read (struct file * file, char * buf, size_t count,
 105                         loff_t * ppos)
 106 {
 107         unsigned int minor = minor (file->f_dentry->d_inode->i_rdev);
 108         struct pp_struct *pp = file->private_data;
 109         char * kbuffer;
 110         ssize_t bytes_read = 0;
 111         struct parport *pport;
 112         int mode;
 113
 114         if (!(pp->flags & PP_CLAIMED)) {
 115                 /* Don't have the port claimed */
 116                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 117                         minor);
 118                 return -EINVAL;
 119         }
 120
 121         /* Trivial case. */
 122         if (count == 0)
 123                 return 0;
 124
 125         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 126         if (!kbuffer) {
 127                 return -ENOMEM;
 128         }
 129         pport = pp->pdev->port;
 130         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 131
 132         parport_set_timeout (pp->pdev,
 133                              (file->f_flags & O_NONBLOCK) ?
 134                              PARPORT_INACTIVITY_O_NONBLOCK :
 135                              pp->default_inactivity);
 136
 137         while (bytes_read == 0) {
 138                 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
 139
 140                 if (mode == IEEE1284_MODE_EPP) {
 141                         /* various specials for EPP mode */
 142                         int flags = 0;
 143                         size_t (*fn)(struct parport *, void *, size_t, int);
 144
 145                         if (pp->flags & PP_W91284PIC) {
 146                                 flags |= PARPORT_W91284PIC;
 147                         }
 148                         if (pp->flags & PP_FASTREAD) {
 149                                 flags |= PARPORT_EPP_FAST;
 150                         }
 151                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 152                                 fn = pport->ops->epp_read_addr;
 153                         } else {
 154                                 fn = pport->ops->epp_read_data;
 155                         }
 156                         bytes_read = (*fn)(pport, kbuffer, need, flags);
 157                 } else {
 158                         bytes_read = parport_read (pport, kbuffer, need);
 159                 }
 160
 161                 if (bytes_read != 0)
 162                         break;
 163
 164                 if (file->f_flags & O_NONBLOCK) {
 165                         bytes_read = -EAGAIN;
 166                         break;
 167                 }
 168
 169                 if (signal_pending (current)) {
 170                         bytes_read = -ERESTARTSYS;
 171                         break;
 172                 }
 173
 174                 cond_resched();
 175         }
 176
 177         parport_set_timeout (pp->pdev, pp->default_inactivity);
 178
 179         if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
 180                 bytes_read = -EFAULT;
 181
 182         kfree (kbuffer);
 183         pp_enable_irq (pp);
 184         return bytes_read;
 185 }
 186
 187 static ssize_t pp_write (struct file * file, const char * buf, size_t count,
 188                          loff_t * ppos)
 189 {
 190         unsigned int minor = minor (file->f_dentry->d_inode->i_rdev);
 191         struct pp_struct *pp = file->private_data;
 192         char * kbuffer;
 193         ssize_t bytes_written = 0;
 194         ssize_t wrote;
 195         int mode;
 196         struct parport *pport;
 197
 198         if (!(pp->flags & PP_CLAIMED)) {
 199                 /* Don't have the port claimed */
 200                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 201                         minor);
 202                 return -EINVAL;
 203         }
 204
 205         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 206         if (!kbuffer) {
 207                 return -ENOMEM;
 208         }
 209         pport = pp->pdev->port;
 210         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 211
 212         parport_set_timeout (pp->pdev,
 213                              (file->f_flags & O_NONBLOCK) ?
 214                              PARPORT_INACTIVITY_O_NONBLOCK :
 215                              pp->default_inactivity);
 216
 217         while (bytes_written < count) {
 218                 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
 219
 220                 if (copy_from_user (kbuffer, buf + bytes_written, n)) {
 221                         bytes_written = -EFAULT;
 222                         break;
 223                 }
 224
 225                 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
 226                         /* do a fast EPP write */
 227                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 228                                 wrote = pport->ops->epp_write_addr (pport,
 229                                         kbuffer, n, PARPORT_EPP_FAST);
 230                         } else {
 231                                 wrote = pport->ops->epp_write_data (pport,
 232                                         kbuffer, n, PARPORT_EPP_FAST);
 233                         }
 234                 } else {
 235                         wrote = parport_write (pp->pdev->port, kbuffer, n);
 236                 }
 237
 238                 if (wrote <= 0) {
 239                         if (!bytes_written) {
 240                                 bytes_written = wrote;
 241                         }
 242                         break;
 243                 }
 244
 245                 bytes_written += wrote;
 246
 247                 if (file->f_flags & O_NONBLOCK) {
 248                         if (!bytes_written)
 249                                 bytes_written = -EAGAIN;
 250                         break;
 251                 }
 252
 253                 if (signal_pending (current)) {
 254                         if (!bytes_written) {
 255                                 bytes_written = -EINTR;
 256                         }
 257                         break;
 258                 }
 259
 260                 cond_resched();
 261         }
 262
 263         parport_set_timeout (pp->pdev, pp->default_inactivity);
 264
 265         kfree (kbuffer);
 266         pp_enable_irq (pp);
 267         return bytes_written;
 268 }
 269
 270 static void pp_irq (int irq, void * private, struct pt_regs * unused)
 271 {
 272         struct pp_struct * pp = (struct pp_struct *) private;
 273
 274         if (pp->irqresponse) {
 275                 parport_write_control (pp->pdev->port, pp->irqctl);
 276                 pp->irqresponse = 0;
 277         }
 278
 279         atomic_inc (&pp->irqc);
 280         wake_up_interruptible (&pp->irq_wait);
 281 }
 282
 283 static int register_device (int minor, struct pp_struct *pp)
 284 {
 285         struct parport *port;
 286         struct pardevice * pdev = NULL;
 287         char *name;
 288         int fl;
 289
 290         name = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
 291         if (name == NULL)
 292                 return -ENOMEM;
 293
 294         sprintf (name, CHRDEV "%x", minor);
 295
 296         port = parport_find_number (minor);
 297         if (!port) {
 298                 printk (KERN_WARNING "%s: no associated port!\n", name);
 299                 kfree (name);
 300                 return -ENXIO;
 301         }
 302
 303         fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 304         pdev = parport_register_device (port, name, NULL,
 305                                         NULL, pp_irq, fl, pp);
 306         parport_put_port (port);
 307
 308         if (!pdev) {
 309                 printk (KERN_WARNING "%s: failed to register device!\n", name);
 310                 kfree (name);
 311                 return -ENXIO;
 312         }
 313
 314         pp->pdev = pdev;
 315         printk (KERN_DEBUG "%s: registered pardevice\n", name);
 316         return 0;
 317 }
 318
 319 static enum ieee1284_phase init_phase (int mode)
 320 {
 321         switch (mode & ~(IEEE1284_DEVICEID
 322                          | IEEE1284_ADDR)) {
 323         case IEEE1284_MODE_NIBBLE:
 324         case IEEE1284_MODE_BYTE:
 325                 return IEEE1284_PH_REV_IDLE;
 326         }
 327         return IEEE1284_PH_FWD_IDLE;
 328 }
 329
 330 static int pp_ioctl(struct inode *inode, struct file *file,
 331                     unsigned int cmd, unsigned long arg)
 332 {
 333         unsigned int minor = minor(inode->i_rdev);
 334         struct pp_struct *pp = file->private_data;
 335         struct parport * port;
 336
 337         /* First handle the cases that don't take arguments. */
 338         switch (cmd) {
 339         case PPCLAIM:
 340             {
 341                 struct ieee1284_info *info;
 342                 int ret;
 343
 344                 if (pp->flags & PP_CLAIMED) {
 345                         printk (KERN_DEBUG CHRDEV
 346                                 "%x: you've already got it!\n", minor);
 347                         return -EINVAL;
 348                 }
 349
 350                 /* Deferred device registration. */
 351                 if (!pp->pdev) {
 352                         int err = register_device (minor, pp);
 353                         if (err) {
 354                                 return err;
 355                         }
 356                 }
 357
 358                 ret = parport_claim_or_block (pp->pdev);
 359                 if (ret < 0)
 360                         return ret;
 361
 362                 pp->flags |= PP_CLAIMED;
 363
 364                 /* For interrupt-reporting to work, we need to be
 365                  * informed of each interrupt. */
 366                 pp_enable_irq (pp);
 367
 368                 /* We may need to fix up the state machine. */
 369                 info = &pp->pdev->port->ieee1284;
 370                 pp->saved_state.mode = info->mode;
 371                 pp->saved_state.phase = info->phase;
 372                 info->mode = pp->state.mode;
 373                 info->phase = pp->state.phase;
 374                 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
 375                 parport_set_timeout (pp->pdev, pp->default_inactivity);
 376
 377                 return 0;
 378             }
 379         case PPEXCL:
 380                 if (pp->pdev) {
 381                         printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
 382                                 "already registered\n", minor);
 383                         if (pp->flags & PP_EXCL)
 384                                 /* But it's not really an error. */
 385                                 return 0;
 386                         /* There's no chance of making the driver happy. */
 387                         return -EINVAL;
 388                 }
 389
 390                 /* Just remember to register the device exclusively
 391                  * when we finally do the registration. */
 392                 pp->flags |= PP_EXCL;
 393                 return 0;
 394         case PPSETMODE:
 395             {
 396                 int mode;
 397                 if (copy_from_user (&mode, (int *) arg, sizeof (mode)))
 398                         return -EFAULT;
 399                 /* FIXME: validate mode */
 400                 pp->state.mode = mode;
 401                 pp->state.phase = init_phase (mode);
 402
 403                 if (pp->flags & PP_CLAIMED) {
 404                         pp->pdev->port->ieee1284.mode = mode;
 405                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 406                 }
 407
 408                 return 0;
 409             }
 410         case PPGETMODE:
 411             {
 412                 int mode;
 413
 414                 if (pp->flags & PP_CLAIMED) {
 415                         mode = pp->pdev->port->ieee1284.mode;
 416                 } else {
 417                         mode = pp->state.mode;
 418                 }
 419                 if (copy_to_user ((int *)arg, &mode, sizeof (mode))) {
 420                         return -EFAULT;
 421                 }
 422                 return 0;
 423             }
 424         case PPSETPHASE:
 425             {
 426                 int phase;
 427                 if (copy_from_user (&phase, (int *) arg, sizeof (phase))) {
 428                         return -EFAULT;
 429                 }
 430                 /* FIXME: validate phase */
 431                 pp->state.phase = phase;
 432
 433                 if (pp->flags & PP_CLAIMED) {
 434                         pp->pdev->port->ieee1284.phase = phase;
 435                 }
 436
 437                 return 0;
 438             }
 439         case PPGETPHASE:
 440             {
 441                 int phase;
 442
 443                 if (pp->flags & PP_CLAIMED) {
 444                         phase = pp->pdev->port->ieee1284.phase;
 445                 } else {
 446                         phase = pp->state.phase;
 447                 }
 448                 if (copy_to_user ((int *)arg, &phase, sizeof (phase))) {
 449                         return -EFAULT;
 450                 }
 451                 return 0;
 452             }
 453         case PPGETMODES:
 454             {
 455                 unsigned int modes;
 456
 457                 port = parport_find_number (minor);
 458                 if (!port)
 459                         return -ENODEV;
 460
 461                 modes = port->modes;
 462                 if (copy_to_user ((unsigned int *)arg, &modes, sizeof (modes))) {
 463                         return -EFAULT;
 464                 }
 465                 return 0;
 466             }
 467         case PPSETFLAGS:
 468             {
 469                 int uflags;
 470
 471                 if (copy_from_user (&uflags, (int *)arg, sizeof (uflags))) {
 472                         return -EFAULT;
 473                 }
 474                 pp->flags &= ~PP_FLAGMASK;
 475                 pp->flags |= (uflags & PP_FLAGMASK);
 476                 return 0;
 477             }
 478         case PPGETFLAGS:
 479             {
 480                 int uflags;
 481
 482                 uflags = pp->flags & PP_FLAGMASK;
 483                 if (copy_to_user ((int *)arg, &uflags, sizeof (uflags))) {
 484                         return -EFAULT;
 485                 }
 486                 return 0;
 487             }
 488         }       /* end switch() */
 489
 490         /* Everything else requires the port to be claimed, so check
 491          * that now. */
 492         if ((pp->flags & PP_CLAIMED) == 0) {
 493                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 494                         minor);
 495                 return -EINVAL;
 496         }
 497
 498         port = pp->pdev->port;
 499         switch (cmd) {
 500                 struct ieee1284_info *info;
 501                 unsigned char reg;
 502                 unsigned char mask;
 503                 int mode;
 504                 int ret;
 505                 struct timeval par_timeout;
 506                 long to_jiffies;
 507
 508         case PPRSTATUS:
 509                 reg = parport_read_status (port);
 510                 if (copy_to_user ((unsigned char *) arg, &reg, sizeof (reg)))
 511                         return -EFAULT;
 512                 return 0;
 513         case PPRDATA:
 514                 reg = parport_read_data (port);
 515                 if (copy_to_user ((unsigned char *) arg, &reg, sizeof (reg)))
 516                         return -EFAULT;
 517                 return 0;
 518         case PPRCONTROL:
 519                 reg = parport_read_control (port);
 520                 if (copy_to_user ((unsigned char *) arg, &reg, sizeof (reg)))
 521                         return -EFAULT;
 522                 return 0;
 523         case PPYIELD:
 524                 parport_yield_blocking (pp->pdev);
 525                 return 0;
 526
 527         case PPRELEASE:
 528                 /* Save the state machine's state. */
 529                 info = &pp->pdev->port->ieee1284;
 530                 pp->state.mode = info->mode;
 531                 pp->state.phase = info->phase;
 532                 info->mode = pp->saved_state.mode;
 533                 info->phase = pp->saved_state.phase;
 534                 parport_release (pp->pdev);
 535                 pp->flags &= ~PP_CLAIMED;
 536                 return 0;
 537
 538         case PPWCONTROL:
 539                 if (copy_from_user (&reg, (unsigned char *) arg, sizeof (reg)))
 540                         return -EFAULT;
 541                 parport_write_control (port, reg);
 542                 return 0;
 543
 544         case PPWDATA:
 545                 if (copy_from_user (&reg, (unsigned char *) arg, sizeof (reg)))
 546                         return -EFAULT;
 547                 parport_write_data (port, reg);
 548                 return 0;
 549
 550         case PPFCONTROL:
 551                 if (copy_from_user (&mask, (unsigned char *) arg,
 552                                     sizeof (mask)))
 553                         return -EFAULT;
 554                 if (copy_from_user (&reg, 1 + (unsigned char *) arg,
 555                                     sizeof (reg)))
 556                         return -EFAULT;
 557                 parport_frob_control (port, mask, reg);
 558                 return 0;
 559
 560         case PPDATADIR:
 561                 if (copy_from_user (&mode, (int *) arg, sizeof (mode)))
 562                         return -EFAULT;
 563                 if (mode)
 564                         port->ops->data_reverse (port);
 565                 else
 566                         port->ops->data_forward (port);
 567                 return 0;
 568
 569         case PPNEGOT:
 570                 if (copy_from_user (&mode, (int *) arg, sizeof (mode)))
 571                         return -EFAULT;
 572                 switch ((ret = parport_negotiate (port, mode))) {
 573                 case 0: break;
 574                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 575                         ret = -EIO;
 576                         break;
 577                 case 1:  /* handshake succeeded, peripheral rejected mode */
 578                         ret = -ENXIO;
 579                         break;
 580                 }
 581                 pp_enable_irq (pp);
 582                 return ret;
 583
 584         case PPWCTLONIRQ:
 585                 if (copy_from_user (&reg, (unsigned char *) arg,
 586                                     sizeof (reg)))
 587                         return -EFAULT;
 588
 589                 /* Remember what to set the control lines to, for next
 590                  * time we get an interrupt. */
 591                 pp->irqctl = reg;
 592                 pp->irqresponse = 1;
 593                 return 0;
 594
 595         case PPCLRIRQ:
 596                 ret = atomic_read (&pp->irqc);
 597                 if (copy_to_user ((int *) arg, &ret, sizeof (ret)))
 598                         return -EFAULT;
 599                 atomic_sub (ret, &pp->irqc);
 600                 return 0;
 601
 602         case PPSETTIME:
 603                 if (copy_from_user (&par_timeout, (struct timeval *)arg,
 604                                     sizeof(struct timeval))) {
 605                         return -EFAULT;
 606                 }
 607                 /* Convert to jiffies, place in pp->pdev->timeout */
 608                 if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
 609                         return -EINVAL;
 610                 }
 611                 to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
 612                 to_jiffies += par_timeout.tv_sec * (long)HZ;
 613                 if (to_jiffies <= 0) {
 614                         return -EINVAL;
 615                 }
 616                 pp->pdev->timeout = to_jiffies;
 617                 return 0;
 618
 619         case PPGETTIME:
 620                 to_jiffies = pp->pdev->timeout;
 621                 par_timeout.tv_sec = to_jiffies / HZ;
 622                 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
 623                 if (copy_to_user ((struct timeval *)arg, &par_timeout,
 624                                   sizeof(struct timeval))) {
 625                         return -EFAULT;
 626                 }
 627                 return 0;
 628
 629         default:
 630                 printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
 631                         cmd);
 632                 return -EINVAL;
 633         }
 634
 635         /* Keep the compiler happy */
 636         return 0;
 637 }
 638
 639 static int pp_open (struct inode * inode, struct file * file)
 640 {
 641         unsigned int minor = minor (inode->i_rdev);
 642         struct pp_struct *pp;
 643
 644         if (minor >= PARPORT_MAX)
 645                 return -ENXIO;
 646
 647         pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
 648         if (!pp)
 649                 return -ENOMEM;
 650
 651         pp->state.mode = IEEE1284_MODE_COMPAT;
 652         pp->state.phase = init_phase (pp->state.mode);
 653         pp->flags = 0;
 654         pp->irqresponse = 0;
 655         atomic_set (&pp->irqc, 0);
 656         init_waitqueue_head (&pp->irq_wait);
 657
 658         /* Defer the actual device registration until the first claim.
 659          * That way, we know whether or not the driver wants to have
 660          * exclusive access to the port (PPEXCL).
 661          */
 662         pp->pdev = NULL;
 663         file->private_data = pp;
 664
 665         return 0;
 666 }
 667
 668 static int pp_release (struct inode * inode, struct file * file)
 669 {
 670         unsigned int minor = minor (inode->i_rdev);
 671         struct pp_struct *pp = file->private_data;
 672         int compat_negot;
 673
 674         compat_negot = 0;
 675         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 676             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 677                 struct ieee1284_info *info;
 678
 679                 /* parport released, but not in compatibility mode */
 680                 parport_claim_or_block (pp->pdev);
 681                 pp->flags |= PP_CLAIMED;
 682                 info = &pp->pdev->port->ieee1284;
 683                 pp->saved_state.mode = info->mode;
 684                 pp->saved_state.phase = info->phase;
 685                 info->mode = pp->state.mode;
 686                 info->phase = pp->state.phase;
 687                 compat_negot = 1;
 688         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 689             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 690                 compat_negot = 2;
 691         }
 692         if (compat_negot) {
 693                 parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
 694                 printk (KERN_DEBUG CHRDEV
 695                         "%x: negotiated back to compatibility mode because "
 696                         "user-space forgot\n", minor);
 697         }
 698
 699         if (pp->flags & PP_CLAIMED) {
 700                 struct ieee1284_info *info;
 701
 702                 info = &pp->pdev->port->ieee1284;
 703                 pp->state.mode = info->mode;
 704                 pp->state.phase = info->phase;
 705                 info->mode = pp->saved_state.mode;
 706                 info->phase = pp->saved_state.phase;
 707                 parport_release (pp->pdev);
 708                 if (compat_negot != 1) {
 709                         printk (KERN_DEBUG CHRDEV "%x: released pardevice "
 710                                 "because user-space forgot\n", minor);
 711                 }
 712         }
 713
 714         if (pp->pdev) {
 715                 const char *name = pp->pdev->name;
 716                 parport_unregister_device (pp->pdev);
 717                 kfree (name);
 718                 pp->pdev = NULL;
 719                 printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
 720                         minor);
 721         }
 722
 723         kfree (pp);
 724
 725         return 0;
 726 }
 727
 728 /* No kernel lock held - fine */
 729 static unsigned int pp_poll (struct file * file, poll_table * wait)
 730 {
 731         struct pp_struct *pp = file->private_data;
 732         unsigned int mask = 0;
 733
 734         poll_wait (file, &pp->irq_wait, wait);
 735         if (atomic_read (&pp->irqc))
 736                 mask |= POLLIN | POLLRDNORM;
 737
 738         return mask;
 739 }
 740
 741 static struct file_operations pp_fops = {
 742         .owner          = THIS_MODULE,
 743         .llseek         = no_llseek,
 744         .read           = pp_read,
 745         .write          = pp_write,
 746         .poll           = pp_poll,
 747         .ioctl          = pp_ioctl,
 748         .open           = pp_open,
 749         .release        = pp_release,
 750 };
 751
 752 static int __init ppdev_init (void)
 753 {
 754         int i;
 755
 756         if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
 757                 printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
 758                         PP_MAJOR);
 759                 return -EIO;
 760         }
 761         devfs_mk_dir("parports");
 762         for (i = 0; i < PARPORT_MAX; i++) {
 763                 devfs_mk_cdev(MKDEV(PP_MAJOR, i),
 764                                 S_IFCHR | S_IRUGO | S_IWUGO, "parports/%d", i);
 765         }
 766
 767         printk (KERN_INFO PP_VERSION "\n");
 768         return 0;
 769 }
 770
 771 static void __exit ppdev_cleanup (void)
 772 {
 773         int i;
 774         /* Clean up all parport stuff */
 775         for (i = 0; i < PARPORT_MAX; i++)
 776                 devfs_remove("parports/%d", i);
 777         devfs_remove("parports");
 778         unregister_chrdev (PP_MAJOR, CHRDEV);
 779 }
 780
 781 module_init(ppdev_init);
 782 module_exit(ppdev_cleanup);
 783
 784 MODULE_LICENSE("GPL");
 785