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->f_path.dentry->d_inode);
 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->f_path.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                 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                         if (!bytes_written) {
 256                                 bytes_written = -EINTR;
 257                         }
 258                         break;
 259                 }
 260
 261                 cond_resched();
 262         }
 263
 264         parport_set_timeout (pp->pdev, pp->default_inactivity);
 265
 266         kfree (kbuffer);
 267         pp_enable_irq (pp);
 268         return bytes_written;
 269 }
 270
 271 static void pp_irq (void *private)
 272 {
 273         struct pp_struct *pp = private;
 274
 275         if (pp->irqresponse) {
 276                 parport_write_control (pp->pdev->port, pp->irqctl);
 277                 pp->irqresponse = 0;
 278         }
 279
 280         atomic_inc (&pp->irqc);
 281         wake_up_interruptible (&pp->irq_wait);
 282 }
 283
 284 static int register_device (int minor, struct pp_struct *pp)
 285 {
 286         struct parport *port;
 287         struct pardevice * pdev = NULL;
 288         char *name;
 289         int fl;
 290
 291         name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
 292         if (name == NULL)
 293                 return -ENOMEM;
 294
 295         port = parport_find_number (minor);
 296         if (!port) {
 297                 printk (KERN_WARNING "%s: no associated port!\n", name);
 298                 kfree (name);
 299                 return -ENXIO;
 300         }
 301
 302         fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 303         pdev = parport_register_device (port, name, NULL,
 304                                         NULL, pp_irq, fl, pp);
 305         parport_put_port (port);
 306
 307         if (!pdev) {
 308                 printk (KERN_WARNING "%s: failed to register device!\n", name);
 309                 kfree (name);
 310                 return -ENXIO;
 311         }
 312
 313         pp->pdev = pdev;
 314         pr_debug("%s: registered pardevice\n", name);
 315         return 0;
 316 }
 317
 318 static enum ieee1284_phase init_phase (int mode)
 319 {
 320         switch (mode & ~(IEEE1284_DEVICEID
 321                          | IEEE1284_ADDR)) {
 322         case IEEE1284_MODE_NIBBLE:
 323         case IEEE1284_MODE_BYTE:
 324                 return IEEE1284_PH_REV_IDLE;
 325         }
 326         return IEEE1284_PH_FWD_IDLE;
 327 }
 328
 329 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 330 {
 331         unsigned int minor = iminor(file->f_path.dentry->d_inode);
 332         struct pp_struct *pp = file->private_data;
 333         struct parport * port;
 334         void __user *argp = (void __user *)arg;
 335
 336         /* First handle the cases that don't take arguments. */
 337         switch (cmd) {
 338         case PPCLAIM:
 339             {
 340                 struct ieee1284_info *info;
 341                 int ret;
 342
 343                 if (pp->flags & PP_CLAIMED) {
 344                         pr_debug(CHRDEV "%x: you've already got it!\n", minor);
 345                         return -EINVAL;
 346                 }
 347
 348                 /* Deferred device registration. */
 349                 if (!pp->pdev) {
 350                         int err = register_device (minor, pp);
 351                         if (err) {
 352                                 return err;
 353                         }
 354                 }
 355
 356                 ret = parport_claim_or_block (pp->pdev);
 357                 if (ret < 0)
 358                         return ret;
 359
 360                 pp->flags |= PP_CLAIMED;
 361
 362                 /* For interrupt-reporting to work, we need to be
 363                  * informed of each interrupt. */
 364                 pp_enable_irq (pp);
 365
 366                 /* We may need to fix up the state machine. */
 367                 info = &pp->pdev->port->ieee1284;
 368                 pp->saved_state.mode = info->mode;
 369                 pp->saved_state.phase = info->phase;
 370                 info->mode = pp->state.mode;
 371                 info->phase = pp->state.phase;
 372                 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
 373                 parport_set_timeout (pp->pdev, pp->default_inactivity);
 374
 375                 return 0;
 376             }
 377         case PPEXCL:
 378                 if (pp->pdev) {
 379                         pr_debug(CHRDEV "%x: too late for PPEXCL; "
 380                                 "already registered\n", minor);
 381                         if (pp->flags & PP_EXCL)
 382                                 /* But it's not really an error. */
 383                                 return 0;
 384                         /* There's no chance of making the driver happy. */
 385                         return -EINVAL;
 386                 }
 387
 388                 /* Just remember to register the device exclusively
 389                  * when we finally do the registration. */
 390                 pp->flags |= PP_EXCL;
 391                 return 0;
 392         case PPSETMODE:
 393             {
 394                 int mode;
 395                 if (copy_from_user (&mode, argp, sizeof (mode)))
 396                         return -EFAULT;
 397                 /* FIXME: validate mode */
 398                 pp->state.mode = mode;
 399                 pp->state.phase = init_phase (mode);
 400
 401                 if (pp->flags & PP_CLAIMED) {
 402                         pp->pdev->port->ieee1284.mode = mode;
 403                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 404                 }
 405
 406                 return 0;
 407             }
 408         case PPGETMODE:
 409             {
 410                 int mode;
 411
 412                 if (pp->flags & PP_CLAIMED) {
 413                         mode = pp->pdev->port->ieee1284.mode;
 414                 } else {
 415                         mode = pp->state.mode;
 416                 }
 417                 if (copy_to_user (argp, &mode, sizeof (mode))) {
 418                         return -EFAULT;
 419                 }
 420                 return 0;
 421             }
 422         case PPSETPHASE:
 423             {
 424                 int phase;
 425                 if (copy_from_user (&phase, argp, sizeof (phase))) {
 426                         return -EFAULT;
 427                 }
 428                 /* FIXME: validate phase */
 429                 pp->state.phase = phase;
 430
 431                 if (pp->flags & PP_CLAIMED) {
 432                         pp->pdev->port->ieee1284.phase = phase;
 433                 }
 434
 435                 return 0;
 436             }
 437         case PPGETPHASE:
 438             {
 439                 int phase;
 440
 441                 if (pp->flags & PP_CLAIMED) {
 442                         phase = pp->pdev->port->ieee1284.phase;
 443                 } else {
 444                         phase = pp->state.phase;
 445                 }
 446                 if (copy_to_user (argp, &phase, sizeof (phase))) {
 447                         return -EFAULT;
 448                 }
 449                 return 0;
 450             }
 451         case PPGETMODES:
 452             {
 453                 unsigned int modes;
 454
 455                 port = parport_find_number (minor);
 456                 if (!port)
 457                         return -ENODEV;
 458
 459                 modes = port->modes;
 460                 if (copy_to_user (argp, &modes, sizeof (modes))) {
 461                         return -EFAULT;
 462                 }
 463                 return 0;
 464             }
 465         case PPSETFLAGS:
 466             {
 467                 int uflags;
 468
 469                 if (copy_from_user (&uflags, argp, sizeof (uflags))) {
 470                         return -EFAULT;
 471                 }
 472                 pp->flags &= ~PP_FLAGMASK;
 473                 pp->flags |= (uflags & PP_FLAGMASK);
 474                 return 0;
 475             }
 476         case PPGETFLAGS:
 477             {
 478                 int uflags;
 479
 480                 uflags = pp->flags & PP_FLAGMASK;
 481                 if (copy_to_user (argp, &uflags, sizeof (uflags))) {
 482                         return -EFAULT;
 483                 }
 484                 return 0;
 485             }
 486         }       /* end switch() */
 487
 488         /* Everything else requires the port to be claimed, so check
 489          * that now. */
 490         if ((pp->flags & PP_CLAIMED) == 0) {
 491                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 492                 return -EINVAL;
 493         }
 494
 495         port = pp->pdev->port;
 496         switch (cmd) {
 497                 struct ieee1284_info *info;
 498                 unsigned char reg;
 499                 unsigned char mask;
 500                 int mode;
 501                 int ret;
 502                 struct timeval par_timeout;
 503                 long to_jiffies;
 504
 505         case PPRSTATUS:
 506                 reg = parport_read_status (port);
 507                 if (copy_to_user (argp, &reg, sizeof (reg)))
 508                         return -EFAULT;
 509                 return 0;
 510         case PPRDATA:
 511                 reg = parport_read_data (port);
 512                 if (copy_to_user (argp, &reg, sizeof (reg)))
 513                         return -EFAULT;
 514                 return 0;
 515         case PPRCONTROL:
 516                 reg = parport_read_control (port);
 517                 if (copy_to_user (argp, &reg, sizeof (reg)))
 518                         return -EFAULT;
 519                 return 0;
 520         case PPYIELD:
 521                 parport_yield_blocking (pp->pdev);
 522                 return 0;
 523
 524         case PPRELEASE:
 525                 /* Save the state machine's state. */
 526                 info = &pp->pdev->port->ieee1284;
 527                 pp->state.mode = info->mode;
 528                 pp->state.phase = info->phase;
 529                 info->mode = pp->saved_state.mode;
 530                 info->phase = pp->saved_state.phase;
 531                 parport_release (pp->pdev);
 532                 pp->flags &= ~PP_CLAIMED;
 533                 return 0;
 534
 535         case PPWCONTROL:
 536                 if (copy_from_user (&reg, argp, sizeof (reg)))
 537                         return -EFAULT;
 538                 parport_write_control (port, reg);
 539                 return 0;
 540
 541         case PPWDATA:
 542                 if (copy_from_user (&reg, argp, sizeof (reg)))
 543                         return -EFAULT;
 544                 parport_write_data (port, reg);
 545                 return 0;
 546
 547         case PPFCONTROL:
 548                 if (copy_from_user (&mask, argp,
 549                                     sizeof (mask)))
 550                         return -EFAULT;
 551                 if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
 552                                     sizeof (reg)))
 553                         return -EFAULT;
 554                 parport_frob_control (port, mask, reg);
 555                 return 0;
 556
 557         case PPDATADIR:
 558                 if (copy_from_user (&mode, argp, sizeof (mode)))
 559                         return -EFAULT;
 560                 if (mode)
 561                         port->ops->data_reverse (port);
 562                 else
 563                         port->ops->data_forward (port);
 564                 return 0;
 565
 566         case PPNEGOT:
 567                 if (copy_from_user (&mode, argp, sizeof (mode)))
 568                         return -EFAULT;
 569                 switch ((ret = parport_negotiate (port, mode))) {
 570                 case 0: break;
 571                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 572                         ret = -EIO;
 573                         break;
 574                 case 1:  /* handshake succeeded, peripheral rejected mode */
 575                         ret = -ENXIO;
 576                         break;
 577                 }
 578                 pp_enable_irq (pp);
 579                 return ret;
 580
 581         case PPWCTLONIRQ:
 582                 if (copy_from_user (&reg, argp, sizeof (reg)))
 583                         return -EFAULT;
 584
 585                 /* Remember what to set the control lines to, for next
 586                  * time we get an interrupt. */
 587                 pp->irqctl = reg;
 588                 pp->irqresponse = 1;
 589                 return 0;
 590
 591         case PPCLRIRQ:
 592                 ret = atomic_read (&pp->irqc);
 593                 if (copy_to_user (argp, &ret, sizeof (ret)))
 594                         return -EFAULT;
 595                 atomic_sub (ret, &pp->irqc);
 596                 return 0;
 597
 598         case PPSETTIME:
 599                 if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
 600                         return -EFAULT;
 601                 }
 602                 /* Convert to jiffies, place in pp->pdev->timeout */
 603                 if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
 604                         return -EINVAL;
 605                 }
 606                 to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
 607                 to_jiffies += par_timeout.tv_sec * (long)HZ;
 608                 if (to_jiffies <= 0) {
 609                         return -EINVAL;
 610                 }
 611                 pp->pdev->timeout = to_jiffies;
 612                 return 0;
 613
 614         case PPGETTIME:
 615                 to_jiffies = pp->pdev->timeout;
 616                 memset(&par_timeout, 0, sizeof(par_timeout));
 617                 par_timeout.tv_sec = to_jiffies / HZ;
 618                 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
 619                 if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
 620                         return -EFAULT;
 621                 return 0;
 622
 623         default:
 624                 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
 625                 return -EINVAL;
 626         }
 627
 628         /* Keep the compiler happy */
 629         return 0;
 630 }
 631
 632 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 633 {
 634         long ret;
 635         mutex_lock(&pp_do_mutex);
 636         ret = pp_do_ioctl(file, cmd, arg);
 637         mutex_unlock(&pp_do_mutex);
 638         return ret;
 639 }
 640
 641 static int pp_open (struct inode * inode, struct file * file)
 642 {
 643         unsigned int minor = iminor(inode);
 644         struct pp_struct *pp;
 645
 646         if (minor >= PARPORT_MAX)
 647                 return -ENXIO;
 648
 649         pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
 650         if (!pp)
 651                 return -ENOMEM;
 652
 653         pp->state.mode = IEEE1284_MODE_COMPAT;
 654         pp->state.phase = init_phase (pp->state.mode);
 655         pp->flags = 0;
 656         pp->irqresponse = 0;
 657         atomic_set (&pp->irqc, 0);
 658         init_waitqueue_head (&pp->irq_wait);
 659
 660         /* Defer the actual device registration until the first claim.
 661          * That way, we know whether or not the driver wants to have
 662          * exclusive access to the port (PPEXCL).
 663          */
 664         pp->pdev = NULL;
 665         file->private_data = pp;
 666
 667         return 0;
 668 }
 669
 670 static int pp_release (struct inode * inode, struct file * file)
 671 {
 672         unsigned int minor = iminor(inode);
 673         struct pp_struct *pp = file->private_data;
 674         int compat_negot;
 675
 676         compat_negot = 0;
 677         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 678             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 679                 struct ieee1284_info *info;
 680
 681                 /* parport released, but not in compatibility mode */
 682                 parport_claim_or_block (pp->pdev);
 683                 pp->flags |= PP_CLAIMED;
 684                 info = &pp->pdev->port->ieee1284;
 685                 pp->saved_state.mode = info->mode;
 686                 pp->saved_state.phase = info->phase;
 687                 info->mode = pp->state.mode;
 688                 info->phase = pp->state.phase;
 689                 compat_negot = 1;
 690         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 691             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 692                 compat_negot = 2;
 693         }
 694         if (compat_negot) {
 695                 parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
 696                 pr_debug(CHRDEV "%x: negotiated back to compatibility "
 697                         "mode because user-space forgot\n", minor);
 698         }
 699
 700         if (pp->flags & PP_CLAIMED) {
 701                 struct ieee1284_info *info;
 702
 703                 info = &pp->pdev->port->ieee1284;
 704                 pp->state.mode = info->mode;
 705                 pp->state.phase = info->phase;
 706                 info->mode = pp->saved_state.mode;
 707                 info->phase = pp->saved_state.phase;
 708                 parport_release (pp->pdev);
 709                 if (compat_negot != 1) {
 710                         pr_debug(CHRDEV "%x: released pardevice "
 711                                 "because user-space forgot\n", minor);
 712                 }
 713         }
 714
 715         if (pp->pdev) {
 716                 const char *name = pp->pdev->name;
 717                 parport_unregister_device (pp->pdev);
 718                 kfree (name);
 719                 pp->pdev = NULL;
 720                 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 721         }
 722
 723         kfree (pp);
 724
 725         return 0;
 726 }
 727
 728 /* No kernel lock held - fine */
 729 static unsigned int pp_poll (struct file * file, poll_table * wait)
 730 {
 731         struct pp_struct *pp = file->private_data;
 732         unsigned int mask = 0;
 733
 734         poll_wait (file, &pp->irq_wait, wait);
 735         if (atomic_read (&pp->irqc))
 736                 mask |= POLLIN | POLLRDNORM;
 737
 738         return mask;
 739 }
 740
 741 static struct class *ppdev_class;
 742
 743 static const struct file_operations pp_fops = {
 744         .owner          = THIS_MODULE,
 745         .llseek         = no_llseek,
 746         .read           = pp_read,
 747         .write          = pp_write,
 748         .poll           = pp_poll,
 749         .unlocked_ioctl = pp_ioctl,
 750         .open           = pp_open,
 751         .release        = pp_release,
 752 };
 753
 754 static void pp_attach(struct parport *port)
 755 {
 756         device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
 757                       NULL, "parport%d", port->number);
 758 }
 759
 760 static void pp_detach(struct parport *port)
 761 {
 762         device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 763 }
 764
 765 static struct parport_driver pp_driver = {
 766         .name           = CHRDEV,
 767         .attach         = pp_attach,
 768         .detach         = pp_detach,
 769 };
 770
 771 static int __init ppdev_init (void)
 772 {
 773         int err = 0;
 774
 775         if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
 776                 printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
 777                         PP_MAJOR);
 778                 return -EIO;
 779         }
 780         ppdev_class = class_create(THIS_MODULE, CHRDEV);
 781         if (IS_ERR(ppdev_class)) {
 782                 err = PTR_ERR(ppdev_class);
 783                 goto out_chrdev;
 784         }
 785         if (parport_register_driver(&pp_driver)) {
 786                 printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
 787                 goto out_class;
 788         }
 789
 790         printk (KERN_INFO PP_VERSION "\n");
 791         goto out;
 792
 793 out_class:
 794         class_destroy(ppdev_class);
 795 out_chrdev:
 796         unregister_chrdev(PP_MAJOR, CHRDEV);
 797 out:
 798         return err;
 799 }
 800
 801 static void __exit ppdev_cleanup (void)
 802 {
 803         /* Clean up all parport stuff */
 804         parport_unregister_driver(&pp_driver);
 805         class_destroy(ppdev_class);
 806         unregister_chrdev (PP_MAJOR, CHRDEV);
 807 }
 808
 809 module_init(ppdev_init);
 810 module_exit(ppdev_cleanup);
 811
 812 MODULE_LICENSE("GPL");
 813 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);