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