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/major.h>
  68 #include <linux/ppdev.h>
  69 #include <linux/smp_lock.h>
  70 #include <linux/device.h>
  71 #include <asm/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_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                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 119                         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->f_dentry->d_inode);
 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                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 203                         minor);
 204                 return -EINVAL;
 205         }
 206
 207         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 208         if (!kbuffer) {
 209                 return -ENOMEM;
 210         }
 211         pport = pp->pdev->port;
 212         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 213
 214         parport_set_timeout (pp->pdev,
 215                              (file->f_flags & O_NONBLOCK) ?
 216                              PARPORT_INACTIVITY_O_NONBLOCK :
 217                              pp->default_inactivity);
 218
 219         while (bytes_written < count) {
 220                 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
 221
 222                 if (copy_from_user (kbuffer, buf + bytes_written, n)) {
 223                         bytes_written = -EFAULT;
 224                         break;
 225                 }
 226
 227                 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
 228                         /* do a fast EPP write */
 229                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 230                                 wrote = pport->ops->epp_write_addr (pport,
 231                                         kbuffer, n, PARPORT_EPP_FAST);
 232                         } else {
 233                                 wrote = pport->ops->epp_write_data (pport,
 234                                         kbuffer, n, PARPORT_EPP_FAST);
 235                         }
 236                 } else {
 237                         wrote = parport_write (pp->pdev->port, kbuffer, n);
 238                 }
 239
 240                 if (wrote <= 0) {
 241                         if (!bytes_written) {
 242                                 bytes_written = wrote;
 243                         }
 244                         break;
 245                 }
 246
 247                 bytes_written += wrote;
 248
 249                 if (file->f_flags & O_NONBLOCK) {
 250                         if (!bytes_written)
 251                                 bytes_written = -EAGAIN;
 252                         break;
 253                 }
 254
 255                 if (signal_pending (current)) {
 256                         if (!bytes_written) {
 257                                 bytes_written = -EINTR;
 258                         }
 259                         break;
 260                 }
 261
 262                 cond_resched();
 263         }
 264
 265         parport_set_timeout (pp->pdev, pp->default_inactivity);
 266
 267         kfree (kbuffer);
 268         pp_enable_irq (pp);
 269         return bytes_written;
 270 }
 271
 272 static void pp_irq (int irq, void * private)
 273 {
 274         struct pp_struct * pp = (struct pp_struct *) private;
 275
 276         if (pp->irqresponse) {
 277                 parport_write_control (pp->pdev->port, pp->irqctl);
 278                 pp->irqresponse = 0;
 279         }
 280
 281         atomic_inc (&pp->irqc);
 282         wake_up_interruptible (&pp->irq_wait);
 283 }
 284
 285 static int register_device (int minor, struct pp_struct *pp)
 286 {
 287         struct parport *port;
 288         struct pardevice * pdev = NULL;
 289         char *name;
 290         int fl;
 291
 292         name = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
 293         if (name == NULL)
 294                 return -ENOMEM;
 295
 296         sprintf (name, CHRDEV "%x", minor);
 297
 298         port = parport_find_number (minor);
 299         if (!port) {
 300                 printk (KERN_WARNING "%s: no associated port!\n", name);
 301                 kfree (name);
 302                 return -ENXIO;
 303         }
 304
 305         fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 306         pdev = parport_register_device (port, name, NULL,
 307                                         NULL, pp_irq, fl, pp);
 308         parport_put_port (port);
 309
 310         if (!pdev) {
 311                 printk (KERN_WARNING "%s: failed to register device!\n", name);
 312                 kfree (name);
 313                 return -ENXIO;
 314         }
 315
 316         pp->pdev = pdev;
 317         printk (KERN_DEBUG "%s: registered pardevice\n", name);
 318         return 0;
 319 }
 320
 321 static enum ieee1284_phase init_phase (int mode)
 322 {
 323         switch (mode & ~(IEEE1284_DEVICEID
 324                          | IEEE1284_ADDR)) {
 325         case IEEE1284_MODE_NIBBLE:
 326         case IEEE1284_MODE_BYTE:
 327                 return IEEE1284_PH_REV_IDLE;
 328         }
 329         return IEEE1284_PH_FWD_IDLE;
 330 }
 331
 332 static int pp_ioctl(struct inode *inode, struct file *file,
 333                     unsigned int cmd, unsigned long arg)
 334 {
 335         unsigned int minor = iminor(inode);
 336         struct pp_struct *pp = file->private_data;
 337         struct parport * port;
 338         void __user *argp = (void __user *)arg;
 339
 340         /* First handle the cases that don't take arguments. */
 341         switch (cmd) {
 342         case PPCLAIM:
 343             {
 344                 struct ieee1284_info *info;
 345                 int ret;
 346
 347                 if (pp->flags & PP_CLAIMED) {
 348                         printk (KERN_DEBUG CHRDEV
 349                                 "%x: you've already got it!\n", minor);
 350                         return -EINVAL;
 351                 }
 352
 353                 /* Deferred device registration. */
 354                 if (!pp->pdev) {
 355                         int err = register_device (minor, pp);
 356                         if (err) {
 357                                 return err;
 358                         }
 359                 }
 360
 361                 ret = parport_claim_or_block (pp->pdev);
 362                 if (ret < 0)
 363                         return ret;
 364
 365                 pp->flags |= PP_CLAIMED;
 366
 367                 /* For interrupt-reporting to work, we need to be
 368                  * informed of each interrupt. */
 369                 pp_enable_irq (pp);
 370
 371                 /* We may need to fix up the state machine. */
 372                 info = &pp->pdev->port->ieee1284;
 373                 pp->saved_state.mode = info->mode;
 374                 pp->saved_state.phase = info->phase;
 375                 info->mode = pp->state.mode;
 376                 info->phase = pp->state.phase;
 377                 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
 378                 parport_set_timeout (pp->pdev, pp->default_inactivity);
 379
 380                 return 0;
 381             }
 382         case PPEXCL:
 383                 if (pp->pdev) {
 384                         printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
 385                                 "already registered\n", minor);
 386                         if (pp->flags & PP_EXCL)
 387                                 /* But it's not really an error. */
 388                                 return 0;
 389                         /* There's no chance of making the driver happy. */
 390                         return -EINVAL;
 391                 }
 392
 393                 /* Just remember to register the device exclusively
 394                  * when we finally do the registration. */
 395                 pp->flags |= PP_EXCL;
 396                 return 0;
 397         case PPSETMODE:
 398             {
 399                 int mode;
 400                 if (copy_from_user (&mode, argp, sizeof (mode)))
 401                         return -EFAULT;
 402                 /* FIXME: validate mode */
 403                 pp->state.mode = mode;
 404                 pp->state.phase = init_phase (mode);
 405
 406                 if (pp->flags & PP_CLAIMED) {
 407                         pp->pdev->port->ieee1284.mode = mode;
 408                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 409                 }
 410
 411                 return 0;
 412             }
 413         case PPGETMODE:
 414             {
 415                 int mode;
 416
 417                 if (pp->flags & PP_CLAIMED) {
 418                         mode = pp->pdev->port->ieee1284.mode;
 419                 } else {
 420                         mode = pp->state.mode;
 421                 }
 422                 if (copy_to_user (argp, &mode, sizeof (mode))) {
 423                         return -EFAULT;
 424                 }
 425                 return 0;
 426             }
 427         case PPSETPHASE:
 428             {
 429                 int phase;
 430                 if (copy_from_user (&phase, argp, sizeof (phase))) {
 431                         return -EFAULT;
 432                 }
 433                 /* FIXME: validate phase */
 434                 pp->state.phase = phase;
 435
 436                 if (pp->flags & PP_CLAIMED) {
 437                         pp->pdev->port->ieee1284.phase = phase;
 438                 }
 439
 440                 return 0;
 441             }
 442         case PPGETPHASE:
 443             {
 444                 int phase;
 445
 446                 if (pp->flags & PP_CLAIMED) {
 447                         phase = pp->pdev->port->ieee1284.phase;
 448                 } else {
 449                         phase = pp->state.phase;
 450                 }
 451                 if (copy_to_user (argp, &phase, sizeof (phase))) {
 452                         return -EFAULT;
 453                 }
 454                 return 0;
 455             }
 456         case PPGETMODES:
 457             {
 458                 unsigned int modes;
 459
 460                 port = parport_find_number (minor);
 461                 if (!port)
 462                         return -ENODEV;
 463
 464                 modes = port->modes;
 465                 if (copy_to_user (argp, &modes, sizeof (modes))) {
 466                         return -EFAULT;
 467                 }
 468                 return 0;
 469             }
 470         case PPSETFLAGS:
 471             {
 472                 int uflags;
 473
 474                 if (copy_from_user (&uflags, argp, sizeof (uflags))) {
 475                         return -EFAULT;
 476                 }
 477                 pp->flags &= ~PP_FLAGMASK;
 478                 pp->flags |= (uflags & PP_FLAGMASK);
 479                 return 0;
 480             }
 481         case PPGETFLAGS:
 482             {
 483                 int uflags;
 484
 485                 uflags = pp->flags & PP_FLAGMASK;
 486                 if (copy_to_user (argp, &uflags, sizeof (uflags))) {
 487                         return -EFAULT;
 488                 }
 489                 return 0;
 490             }
 491         }       /* end switch() */
 492
 493         /* Everything else requires the port to be claimed, so check
 494          * that now. */
 495         if ((pp->flags & PP_CLAIMED) == 0) {
 496                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 497                         minor);
 498                 return -EINVAL;
 499         }
 500
 501         port = pp->pdev->port;
 502         switch (cmd) {
 503                 struct ieee1284_info *info;
 504                 unsigned char reg;
 505                 unsigned char mask;
 506                 int mode;
 507                 int ret;
 508                 struct timeval par_timeout;
 509                 long to_jiffies;
 510
 511         case PPRSTATUS:
 512                 reg = parport_read_status (port);
 513                 if (copy_to_user (argp, &reg, sizeof (reg)))
 514                         return -EFAULT;
 515                 return 0;
 516         case PPRDATA:
 517                 reg = parport_read_data (port);
 518                 if (copy_to_user (argp, &reg, sizeof (reg)))
 519                         return -EFAULT;
 520                 return 0;
 521         case PPRCONTROL:
 522                 reg = parport_read_control (port);
 523                 if (copy_to_user (argp, &reg, sizeof (reg)))
 524                         return -EFAULT;
 525                 return 0;
 526         case PPYIELD:
 527                 parport_yield_blocking (pp->pdev);
 528                 return 0;
 529
 530         case PPRELEASE:
 531                 /* Save the state machine's state. */
 532                 info = &pp->pdev->port->ieee1284;
 533                 pp->state.mode = info->mode;
 534                 pp->state.phase = info->phase;
 535                 info->mode = pp->saved_state.mode;
 536                 info->phase = pp->saved_state.phase;
 537                 parport_release (pp->pdev);
 538                 pp->flags &= ~PP_CLAIMED;
 539                 return 0;
 540
 541         case PPWCONTROL:
 542                 if (copy_from_user (&reg, argp, sizeof (reg)))
 543                         return -EFAULT;
 544                 parport_write_control (port, reg);
 545                 return 0;
 546
 547         case PPWDATA:
 548                 if (copy_from_user (&reg, argp, sizeof (reg)))
 549                         return -EFAULT;
 550                 parport_write_data (port, reg);
 551                 return 0;
 552
 553         case PPFCONTROL:
 554                 if (copy_from_user (&mask, argp,
 555                                     sizeof (mask)))
 556                         return -EFAULT;
 557                 if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
 558                                     sizeof (reg)))
 559                         return -EFAULT;
 560                 parport_frob_control (port, mask, reg);
 561                 return 0;
 562
 563         case PPDATADIR:
 564                 if (copy_from_user (&mode, argp, sizeof (mode)))
 565                         return -EFAULT;
 566                 if (mode)
 567                         port->ops->data_reverse (port);
 568                 else
 569                         port->ops->data_forward (port);
 570                 return 0;
 571
 572         case PPNEGOT:
 573                 if (copy_from_user (&mode, argp, sizeof (mode)))
 574                         return -EFAULT;
 575                 switch ((ret = parport_negotiate (port, mode))) {
 576                 case 0: break;
 577                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 578                         ret = -EIO;
 579                         break;
 580                 case 1:  /* handshake succeeded, peripheral rejected mode */
 581                         ret = -ENXIO;
 582                         break;
 583                 }
 584                 pp_enable_irq (pp);
 585                 return ret;
 586
 587         case PPWCTLONIRQ:
 588                 if (copy_from_user (&reg, argp, sizeof (reg)))
 589                         return -EFAULT;
 590
 591                 /* Remember what to set the control lines to, for next
 592                  * time we get an interrupt. */
 593                 pp->irqctl = reg;
 594                 pp->irqresponse = 1;
 595                 return 0;
 596
 597         case PPCLRIRQ:
 598                 ret = atomic_read (&pp->irqc);
 599                 if (copy_to_user (argp, &ret, sizeof (ret)))
 600                         return -EFAULT;
 601                 atomic_sub (ret, &pp->irqc);
 602                 return 0;
 603
 604         case PPSETTIME:
 605                 if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
 606                         return -EFAULT;
 607                 }
 608                 /* Convert to jiffies, place in pp->pdev->timeout */
 609                 if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
 610                         return -EINVAL;
 611                 }
 612                 to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
 613                 to_jiffies += par_timeout.tv_sec * (long)HZ;
 614                 if (to_jiffies <= 0) {
 615                         return -EINVAL;
 616                 }
 617                 pp->pdev->timeout = to_jiffies;
 618                 return 0;
 619
 620         case PPGETTIME:
 621                 to_jiffies = pp->pdev->timeout;
 622                 par_timeout.tv_sec = to_jiffies / HZ;
 623                 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
 624                 if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
 625                         return -EFAULT;
 626                 return 0;
 627
 628         default:
 629                 printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
 630                         cmd);
 631                 return -EINVAL;
 632         }
 633
 634         /* Keep the compiler happy */
 635         return 0;
 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                 printk (KERN_DEBUG CHRDEV
 694                         "%x: negotiated back to compatibility mode because "
 695                         "user-space forgot\n", minor);
 696         }
 697
 698         if (pp->flags & PP_CLAIMED) {
 699                 struct ieee1284_info *info;
 700
 701                 info = &pp->pdev->port->ieee1284;
 702                 pp->state.mode = info->mode;
 703                 pp->state.phase = info->phase;
 704                 info->mode = pp->saved_state.mode;
 705                 info->phase = pp->saved_state.phase;
 706                 parport_release (pp->pdev);
 707                 if (compat_negot != 1) {
 708                         printk (KERN_DEBUG CHRDEV "%x: released pardevice "
 709                                 "because user-space forgot\n", minor);
 710                 }
 711         }
 712
 713         if (pp->pdev) {
 714                 const char *name = pp->pdev->name;
 715                 parport_unregister_device (pp->pdev);
 716                 kfree (name);
 717                 pp->pdev = NULL;
 718                 printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
 719                         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         .ioctl          = pp_ioctl,
 749         .open           = pp_open,
 750         .release        = pp_release,
 751 };
 752
 753 static void pp_attach(struct parport *port)
 754 {
 755         class_device_create(ppdev_class, NULL, MKDEV(PP_MAJOR, port->number),
 756                         NULL, "parport%d", port->number);
 757 }
 758
 759 static void pp_detach(struct parport *port)
 760 {
 761         class_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);