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/device.h>
  63 #include <linux/ioctl.h>
  64 #include <linux/parport.h>
  65 #include <linux/ctype.h>
  66 #include <linux/poll.h>
  67 #include <linux/slab.h>
  68 #include <linux/major.h>
  69 #include <linux/ppdev.h>
  70 #include <linux/mutex.h>
  71 #include <linux/uaccess.h>
  72
  73 #define PP_VERSION "ppdev: user-space parallel port driver"
  74 #define CHRDEV "ppdev"
  75
  76 struct pp_struct {
  77         struct pardevice * pdev;
  78         wait_queue_head_t irq_wait;
  79         atomic_t irqc;
  80         unsigned int flags;
  81         int irqresponse;
  82         unsigned char irqctl;
  83         struct ieee1284_info state;
  84         struct ieee1284_info saved_state;
  85         long default_inactivity;
  86 };
  87
  88 /* pp_struct.flags bitfields */
  89 #define PP_CLAIMED    (1<<0)
  90 #define PP_EXCL       (1<<1)
  91
  92 /* Other constants */
  93 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
  94 #define PP_BUFFER_SIZE 1024
  95 #define PARDEVICE_MAX 8
  96
  97 /* ROUND_UP macro from fs/select.c */
  98 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
  99
 100 static DEFINE_MUTEX(pp_do_mutex);
 101 static inline void pp_enable_irq (struct pp_struct *pp)
 102 {
 103         struct parport *port = pp->pdev->port;
 104         port->ops->enable_irq (port);
 105 }
 106
 107 static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
 108                         loff_t * ppos)
 109 {
 110         unsigned int minor = iminor(file_inode(file));
 111         struct pp_struct *pp = file->private_data;
 112         char * kbuffer;
 113         ssize_t bytes_read = 0;
 114         struct parport *pport;
 115         int mode;
 116
 117         if (!(pp->flags & PP_CLAIMED)) {
 118                 /* Don't have the port claimed */
 119                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 120                 return -EINVAL;
 121         }
 122
 123         /* Trivial case. */
 124         if (count == 0)
 125                 return 0;
 126
 127         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 128         if (!kbuffer) {
 129                 return -ENOMEM;
 130         }
 131         pport = pp->pdev->port;
 132         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 133
 134         parport_set_timeout (pp->pdev,
 135                              (file->f_flags & O_NONBLOCK) ?
 136                              PARPORT_INACTIVITY_O_NONBLOCK :
 137                              pp->default_inactivity);
 138
 139         while (bytes_read == 0) {
 140                 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
 141
 142                 if (mode == IEEE1284_MODE_EPP) {
 143                         /* various specials for EPP mode */
 144                         int flags = 0;
 145                         size_t (*fn)(struct parport *, void *, size_t, int);
 146
 147                         if (pp->flags & PP_W91284PIC) {
 148                                 flags |= PARPORT_W91284PIC;
 149                         }
 150                         if (pp->flags & PP_FASTREAD) {
 151                                 flags |= PARPORT_EPP_FAST;
 152                         }
 153                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 154                                 fn = pport->ops->epp_read_addr;
 155                         } else {
 156                                 fn = pport->ops->epp_read_data;
 157                         }
 158                         bytes_read = (*fn)(pport, kbuffer, need, flags);
 159                 } else {
 160                         bytes_read = parport_read (pport, kbuffer, need);
 161                 }
 162
 163                 if (bytes_read != 0)
 164                         break;
 165
 166                 if (file->f_flags & O_NONBLOCK) {
 167                         bytes_read = -EAGAIN;
 168                         break;
 169                 }
 170
 171                 if (signal_pending (current)) {
 172                         bytes_read = -ERESTARTSYS;
 173                         break;
 174                 }
 175
 176                 cond_resched();
 177         }
 178
 179         parport_set_timeout (pp->pdev, pp->default_inactivity);
 180
 181         if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
 182                 bytes_read = -EFAULT;
 183
 184         kfree (kbuffer);
 185         pp_enable_irq (pp);
 186         return bytes_read;
 187 }
 188
 189 static ssize_t pp_write (struct file * file, const char __user * buf,
 190                          size_t count, loff_t * ppos)
 191 {
 192         unsigned int minor = iminor(file_inode(file));
 193         struct pp_struct *pp = file->private_data;
 194         char * kbuffer;
 195         ssize_t bytes_written = 0;
 196         ssize_t wrote;
 197         int mode;
 198         struct parport *pport;
 199
 200         if (!(pp->flags & PP_CLAIMED)) {
 201                 /* Don't have the port claimed */
 202                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 203                 return -EINVAL;
 204         }
 205
 206         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 207         if (!kbuffer) {
 208                 return -ENOMEM;
 209         }
 210         pport = pp->pdev->port;
 211         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 212
 213         parport_set_timeout (pp->pdev,
 214                              (file->f_flags & O_NONBLOCK) ?
 215                              PARPORT_INACTIVITY_O_NONBLOCK :
 216                              pp->default_inactivity);
 217
 218         while (bytes_written < count) {
 219                 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
 220
 221                 if (copy_from_user (kbuffer, buf + bytes_written, n)) {
 222                         bytes_written = -EFAULT;
 223                         break;
 224                 }
 225
 226                 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
 227                         /* do a fast EPP write */
 228                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 229                                 wrote = pport->ops->epp_write_addr (pport,
 230                                         kbuffer, n, PARPORT_EPP_FAST);
 231                         } else {
 232                                 wrote = pport->ops->epp_write_data (pport,
 233                                         kbuffer, n, PARPORT_EPP_FAST);
 234                         }
 235                 } else {
 236                         wrote = parport_write (pp->pdev->port, kbuffer, n);
 237                 }
 238
 239                 if (wrote <= 0) {
 240                         if (!bytes_written) {
 241                                 bytes_written = wrote;
 242                         }
 243                         break;
 244                 }
 245
 246                 bytes_written += wrote;
 247
 248                 if (file->f_flags & O_NONBLOCK) {
 249                         if (!bytes_written)
 250                                 bytes_written = -EAGAIN;
 251                         break;
 252                 }
 253
 254                 if (signal_pending (current))
 255                         break;
 256
 257                 cond_resched();
 258         }
 259
 260         parport_set_timeout (pp->pdev, pp->default_inactivity);
 261
 262         kfree (kbuffer);
 263         pp_enable_irq (pp);
 264         return bytes_written;
 265 }
 266
 267 static void pp_irq (void *private)
 268 {
 269         struct pp_struct *pp = private;
 270
 271         if (pp->irqresponse) {
 272                 parport_write_control (pp->pdev->port, pp->irqctl);
 273                 pp->irqresponse = 0;
 274         }
 275
 276         atomic_inc (&pp->irqc);
 277         wake_up_interruptible (&pp->irq_wait);
 278 }
 279
 280 static int register_device (int minor, struct pp_struct *pp)
 281 {
 282         struct parport *port;
 283         struct pardevice * pdev = NULL;
 284         char *name;
 285         int fl;
 286
 287         name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
 288         if (name == NULL)
 289                 return -ENOMEM;
 290
 291         port = parport_find_number (minor);
 292         if (!port) {
 293                 printk (KERN_WARNING "%s: no associated port!\n", name);
 294                 kfree (name);
 295                 return -ENXIO;
 296         }
 297
 298         fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 299         pdev = parport_register_device (port, name, NULL,
 300                                         NULL, pp_irq, fl, pp);
 301         parport_put_port (port);
 302
 303         if (!pdev) {
 304                 printk (KERN_WARNING "%s: failed to register device!\n", name);
 305                 kfree (name);
 306                 return -ENXIO;
 307         }
 308
 309         pp->pdev = pdev;
 310         pr_debug("%s: registered pardevice\n", name);
 311         return 0;
 312 }
 313
 314 static enum ieee1284_phase init_phase (int mode)
 315 {
 316         switch (mode & ~(IEEE1284_DEVICEID
 317                          | IEEE1284_ADDR)) {
 318         case IEEE1284_MODE_NIBBLE:
 319         case IEEE1284_MODE_BYTE:
 320                 return IEEE1284_PH_REV_IDLE;
 321         }
 322         return IEEE1284_PH_FWD_IDLE;
 323 }
 324
 325 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 326 {
 327         unsigned int minor = iminor(file_inode(file));
 328         struct pp_struct *pp = file->private_data;
 329         struct parport * port;
 330         void __user *argp = (void __user *)arg;
 331
 332         /* First handle the cases that don't take arguments. */
 333         switch (cmd) {
 334         case PPCLAIM:
 335             {
 336                 struct ieee1284_info *info;
 337                 int ret;
 338
 339                 if (pp->flags & PP_CLAIMED) {
 340                         pr_debug(CHRDEV "%x: you've already got it!\n", minor);
 341                         return -EINVAL;
 342                 }
 343
 344                 /* Deferred device registration. */
 345                 if (!pp->pdev) {
 346                         int err = register_device (minor, pp);
 347                         if (err) {
 348                                 return err;
 349                         }
 350                 }
 351
 352                 ret = parport_claim_or_block (pp->pdev);
 353                 if (ret < 0)
 354                         return ret;
 355
 356                 pp->flags |= PP_CLAIMED;
 357
 358                 /* For interrupt-reporting to work, we need to be
 359                  * informed of each interrupt. */
 360                 pp_enable_irq (pp);
 361
 362                 /* We may need to fix up the state machine. */
 363                 info = &pp->pdev->port->ieee1284;
 364                 pp->saved_state.mode = info->mode;
 365                 pp->saved_state.phase = info->phase;
 366                 info->mode = pp->state.mode;
 367                 info->phase = pp->state.phase;
 368                 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
 369                 parport_set_timeout (pp->pdev, pp->default_inactivity);
 370
 371                 return 0;
 372             }
 373         case PPEXCL:
 374                 if (pp->pdev) {
 375                         pr_debug(CHRDEV "%x: too late for PPEXCL; "
 376                                 "already registered\n", minor);
 377                         if (pp->flags & PP_EXCL)
 378                                 /* But it's not really an error. */
 379                                 return 0;
 380                         /* There's no chance of making the driver happy. */
 381                         return -EINVAL;
 382                 }
 383
 384                 /* Just remember to register the device exclusively
 385                  * when we finally do the registration. */
 386                 pp->flags |= PP_EXCL;
 387                 return 0;
 388         case PPSETMODE:
 389             {
 390                 int mode;
 391                 if (copy_from_user (&mode, argp, sizeof (mode)))
 392                         return -EFAULT;
 393                 /* FIXME: validate mode */
 394                 pp->state.mode = mode;
 395                 pp->state.phase = init_phase (mode);
 396
 397                 if (pp->flags & PP_CLAIMED) {
 398                         pp->pdev->port->ieee1284.mode = mode;
 399                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 400                 }
 401
 402                 return 0;
 403             }
 404         case PPGETMODE:
 405             {
 406                 int mode;
 407
 408                 if (pp->flags & PP_CLAIMED) {
 409                         mode = pp->pdev->port->ieee1284.mode;
 410                 } else {
 411                         mode = pp->state.mode;
 412                 }
 413                 if (copy_to_user (argp, &mode, sizeof (mode))) {
 414                         return -EFAULT;
 415                 }
 416                 return 0;
 417             }
 418         case PPSETPHASE:
 419             {
 420                 int phase;
 421                 if (copy_from_user (&phase, argp, sizeof (phase))) {
 422                         return -EFAULT;
 423                 }
 424                 /* FIXME: validate phase */
 425                 pp->state.phase = phase;
 426
 427                 if (pp->flags & PP_CLAIMED) {
 428                         pp->pdev->port->ieee1284.phase = phase;
 429                 }
 430
 431                 return 0;
 432             }
 433         case PPGETPHASE:
 434             {
 435                 int phase;
 436
 437                 if (pp->flags & PP_CLAIMED) {
 438                         phase = pp->pdev->port->ieee1284.phase;
 439                 } else {
 440                         phase = pp->state.phase;
 441                 }
 442                 if (copy_to_user (argp, &phase, sizeof (phase))) {
 443                         return -EFAULT;
 444                 }
 445                 return 0;
 446             }
 447         case PPGETMODES:
 448             {
 449                 unsigned int modes;
 450
 451                 port = parport_find_number (minor);
 452                 if (!port)
 453                         return -ENODEV;
 454
 455                 modes = port->modes;
 456                 parport_put_port(port);
 457                 if (copy_to_user (argp, &modes, sizeof (modes))) {
 458                         return -EFAULT;
 459                 }
 460                 return 0;
 461             }
 462         case PPSETFLAGS:
 463             {
 464                 int uflags;
 465
 466                 if (copy_from_user (&uflags, argp, sizeof (uflags))) {
 467                         return -EFAULT;
 468                 }
 469                 pp->flags &= ~PP_FLAGMASK;
 470                 pp->flags |= (uflags & PP_FLAGMASK);
 471                 return 0;
 472             }
 473         case PPGETFLAGS:
 474             {
 475                 int uflags;
 476
 477                 uflags = pp->flags & PP_FLAGMASK;
 478                 if (copy_to_user (argp, &uflags, sizeof (uflags))) {
 479                         return -EFAULT;
 480                 }
 481                 return 0;
 482             }
 483         }       /* end switch() */
 484
 485         /* Everything else requires the port to be claimed, so check
 486          * that now. */
 487         if ((pp->flags & PP_CLAIMED) == 0) {
 488                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 489                 return -EINVAL;
 490         }
 491
 492         port = pp->pdev->port;
 493         switch (cmd) {
 494                 struct ieee1284_info *info;
 495                 unsigned char reg;
 496                 unsigned char mask;
 497                 int mode;
 498                 int ret;
 499                 struct timeval par_timeout;
 500                 long to_jiffies;
 501
 502         case PPRSTATUS:
 503                 reg = parport_read_status (port);
 504                 if (copy_to_user (argp, &reg, sizeof (reg)))
 505                         return -EFAULT;
 506                 return 0;
 507         case PPRDATA:
 508                 reg = parport_read_data (port);
 509                 if (copy_to_user (argp, &reg, sizeof (reg)))
 510                         return -EFAULT;
 511                 return 0;
 512         case PPRCONTROL:
 513                 reg = parport_read_control (port);
 514                 if (copy_to_user (argp, &reg, sizeof (reg)))
 515                         return -EFAULT;
 516                 return 0;
 517         case PPYIELD:
 518                 parport_yield_blocking (pp->pdev);
 519                 return 0;
 520
 521         case PPRELEASE:
 522                 /* Save the state machine's state. */
 523                 info = &pp->pdev->port->ieee1284;
 524                 pp->state.mode = info->mode;
 525                 pp->state.phase = info->phase;
 526                 info->mode = pp->saved_state.mode;
 527                 info->phase = pp->saved_state.phase;
 528                 parport_release (pp->pdev);
 529                 pp->flags &= ~PP_CLAIMED;
 530                 return 0;
 531
 532         case PPWCONTROL:
 533                 if (copy_from_user (&reg, argp, sizeof (reg)))
 534                         return -EFAULT;
 535                 parport_write_control (port, reg);
 536                 return 0;
 537
 538         case PPWDATA:
 539                 if (copy_from_user (&reg, argp, sizeof (reg)))
 540                         return -EFAULT;
 541                 parport_write_data (port, reg);
 542                 return 0;
 543
 544         case PPFCONTROL:
 545                 if (copy_from_user (&mask, argp,
 546                                     sizeof (mask)))
 547                         return -EFAULT;
 548                 if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
 549                                     sizeof (reg)))
 550                         return -EFAULT;
 551                 parport_frob_control (port, mask, reg);
 552                 return 0;
 553
 554         case PPDATADIR:
 555                 if (copy_from_user (&mode, argp, sizeof (mode)))
 556                         return -EFAULT;
 557                 if (mode)
 558                         port->ops->data_reverse (port);
 559                 else
 560                         port->ops->data_forward (port);
 561                 return 0;
 562
 563         case PPNEGOT:
 564                 if (copy_from_user (&mode, argp, sizeof (mode)))
 565                         return -EFAULT;
 566                 switch ((ret = parport_negotiate (port, mode))) {
 567                 case 0: break;
 568                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 569                         ret = -EIO;
 570                         break;
 571                 case 1:  /* handshake succeeded, peripheral rejected mode */
 572                         ret = -ENXIO;
 573                         break;
 574                 }
 575                 pp_enable_irq (pp);
 576                 return ret;
 577
 578         case PPWCTLONIRQ:
 579                 if (copy_from_user (&reg, argp, sizeof (reg)))
 580                         return -EFAULT;
 581
 582                 /* Remember what to set the control lines to, for next
 583                  * time we get an interrupt. */
 584                 pp->irqctl = reg;
 585                 pp->irqresponse = 1;
 586                 return 0;
 587
 588         case PPCLRIRQ:
 589                 ret = atomic_read (&pp->irqc);
 590                 if (copy_to_user (argp, &ret, sizeof (ret)))
 591                         return -EFAULT;
 592                 atomic_sub (ret, &pp->irqc);
 593                 return 0;
 594
 595         case PPSETTIME:
 596                 if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
 597                         return -EFAULT;
 598                 }
 599                 /* Convert to jiffies, place in pp->pdev->timeout */
 600                 if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
 601                         return -EINVAL;
 602                 }
 603                 to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
 604                 to_jiffies += par_timeout.tv_sec * (long)HZ;
 605                 if (to_jiffies <= 0) {
 606                         return -EINVAL;
 607                 }
 608                 pp->pdev->timeout = to_jiffies;
 609                 return 0;
 610
 611         case PPGETTIME:
 612                 to_jiffies = pp->pdev->timeout;
 613                 memset(&par_timeout, 0, sizeof(par_timeout));
 614                 par_timeout.tv_sec = to_jiffies / HZ;
 615                 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
 616                 if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
 617                         return -EFAULT;
 618                 return 0;
 619
 620         default:
 621                 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
 622                 return -EINVAL;
 623         }
 624
 625         /* Keep the compiler happy */
 626         return 0;
 627 }
 628
 629 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 630 {
 631         long ret;
 632         mutex_lock(&pp_do_mutex);
 633         ret = pp_do_ioctl(file, cmd, arg);
 634         mutex_unlock(&pp_do_mutex);
 635         return ret;
 636 }
 637
 638 static int pp_open (struct inode * inode, struct file * file)
 639 {
 640         unsigned int minor = iminor(inode);
 641         struct pp_struct *pp;
 642
 643         if (minor >= PARPORT_MAX)
 644                 return -ENXIO;
 645
 646         pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
 647         if (!pp)
 648                 return -ENOMEM;
 649
 650         pp->state.mode = IEEE1284_MODE_COMPAT;
 651         pp->state.phase = init_phase (pp->state.mode);
 652         pp->flags = 0;
 653         pp->irqresponse = 0;
 654         atomic_set (&pp->irqc, 0);
 655         init_waitqueue_head (&pp->irq_wait);
 656
 657         /* Defer the actual device registration until the first claim.
 658          * That way, we know whether or not the driver wants to have
 659          * exclusive access to the port (PPEXCL).
 660          */
 661         pp->pdev = NULL;
 662         file->private_data = pp;
 663
 664         return 0;
 665 }
 666
 667 static int pp_release (struct inode * inode, struct file * file)
 668 {
 669         unsigned int minor = iminor(inode);
 670         struct pp_struct *pp = file->private_data;
 671         int compat_negot;
 672
 673         compat_negot = 0;
 674         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 675             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 676                 struct ieee1284_info *info;
 677
 678                 /* parport released, but not in compatibility mode */
 679                 parport_claim_or_block (pp->pdev);
 680                 pp->flags |= PP_CLAIMED;
 681                 info = &pp->pdev->port->ieee1284;
 682                 pp->saved_state.mode = info->mode;
 683                 pp->saved_state.phase = info->phase;
 684                 info->mode = pp->state.mode;
 685                 info->phase = pp->state.phase;
 686                 compat_negot = 1;
 687         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 688             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 689                 compat_negot = 2;
 690         }
 691         if (compat_negot) {
 692                 parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
 693                 pr_debug(CHRDEV "%x: negotiated back to compatibility "
 694                         "mode because user-space forgot\n", minor);
 695         }
 696
 697         if (pp->flags & PP_CLAIMED) {
 698                 struct ieee1284_info *info;
 699
 700                 info = &pp->pdev->port->ieee1284;
 701                 pp->state.mode = info->mode;
 702                 pp->state.phase = info->phase;
 703                 info->mode = pp->saved_state.mode;
 704                 info->phase = pp->saved_state.phase;
 705                 parport_release (pp->pdev);
 706                 if (compat_negot != 1) {
 707                         pr_debug(CHRDEV "%x: released pardevice "
 708                                 "because user-space forgot\n", minor);
 709                 }
 710         }
 711
 712         if (pp->pdev) {
 713                 const char *name = pp->pdev->name;
 714                 parport_unregister_device (pp->pdev);
 715                 kfree (name);
 716                 pp->pdev = NULL;
 717                 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 718         }
 719
 720         kfree (pp);
 721
 722         return 0;
 723 }
 724
 725 /* No kernel lock held - fine */
 726 static unsigned int pp_poll (struct file * file, poll_table * wait)
 727 {
 728         struct pp_struct *pp = file->private_data;
 729         unsigned int mask = 0;
 730
 731         poll_wait (file, &pp->irq_wait, wait);
 732         if (atomic_read (&pp->irqc))
 733                 mask |= POLLIN | POLLRDNORM;
 734
 735         return mask;
 736 }
 737
 738 static struct class *ppdev_class;
 739
 740 static const struct file_operations pp_fops = {
 741         .owner          = THIS_MODULE,
 742         .llseek         = no_llseek,
 743         .read           = pp_read,
 744         .write          = pp_write,
 745         .poll           = pp_poll,
 746         .unlocked_ioctl = pp_ioctl,
 747         .open           = pp_open,
 748         .release        = pp_release,
 749 };
 750
 751 static void pp_attach(struct parport *port)
 752 {
 753         device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
 754                       NULL, "parport%d", port->number);
 755 }
 756
 757 static void pp_detach(struct parport *port)
 758 {
 759         device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 760 }
 761
 762 static struct parport_driver pp_driver = {
 763         .name           = CHRDEV,
 764         .attach         = pp_attach,
 765         .detach         = pp_detach,
 766 };
 767
 768 static int __init ppdev_init (void)
 769 {
 770         int err = 0;
 771
 772         if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
 773                 printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
 774                         PP_MAJOR);
 775                 return -EIO;
 776         }
 777         ppdev_class = class_create(THIS_MODULE, CHRDEV);
 778         if (IS_ERR(ppdev_class)) {
 779                 err = PTR_ERR(ppdev_class);
 780                 goto out_chrdev;
 781         }
 782         err = parport_register_driver(&pp_driver);
 783         if (err < 0) {
 784                 printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
 785                 goto out_class;
 786         }
 787
 788         printk (KERN_INFO PP_VERSION "\n");
 789         goto out;
 790
 791 out_class:
 792         class_destroy(ppdev_class);
 793 out_chrdev:
 794         unregister_chrdev(PP_MAJOR, CHRDEV);
 795 out:
 796         return err;
 797 }
 798
 799 static void __exit ppdev_cleanup (void)
 800 {
 801         /* Clean up all parport stuff */
 802         parport_unregister_driver(&pp_driver);
 803         class_destroy(ppdev_class);
 804         unregister_chrdev (PP_MAJOR, CHRDEV);
 805 }
 806
 807 module_init(ppdev_init);
 808 module_exit(ppdev_cleanup);
 809
 810 MODULE_LICENSE("GPL");
 811 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);