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/device.h>
  70 #include <asm/uaccess.h>
  71
  72 #define PP_VERSION "ppdev: user-space parallel port driver"
  73 #define CHRDEV "ppdev"
  74
  75 struct pp_struct {
  76         struct pardevice * pdev;
  77         wait_queue_head_t irq_wait;
  78         atomic_t irqc;
  79         unsigned int flags;
  80         int irqresponse;
  81         unsigned char irqctl;
  82         struct ieee1284_info state;
  83         struct ieee1284_info saved_state;
  84         long default_inactivity;
  85 };
  86
  87 /* pp_struct.flags bitfields */
  88 #define PP_CLAIMED    (1<<0)
  89 #define PP_EXCL       (1<<1)
  90
  91 /* Other constants */
  92 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
  93 #define PP_BUFFER_SIZE 1024
  94 #define PARDEVICE_MAX 8
  95
  96 /* ROUND_UP macro from fs/select.c */
  97 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
  98
  99 static inline void pp_enable_irq (struct pp_struct *pp)
 100 {
 101         struct parport *port = pp->pdev->port;
 102         port->ops->enable_irq (port);
 103 }
 104
 105 static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
 106                         loff_t * ppos)
 107 {
 108         unsigned int minor = iminor(file->f_path.dentry->d_inode);
 109         struct pp_struct *pp = file->private_data;
 110         char * kbuffer;
 111         ssize_t bytes_read = 0;
 112         struct parport *pport;
 113         int mode;
 114
 115         if (!(pp->flags & PP_CLAIMED)) {
 116                 /* Don't have the port claimed */
 117                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 118                         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                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 202                         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 (int irq, void * private)
 272 {
 273         struct pp_struct * pp = (struct pp_struct *) 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 = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
 292         if (name == NULL)
 293                 return -ENOMEM;
 294
 295         sprintf (name, CHRDEV "%x", minor);
 296
 297         port = parport_find_number (minor);
 298         if (!port) {
 299                 printk (KERN_WARNING "%s: no associated port!\n", name);
 300                 kfree (name);
 301                 return -ENXIO;
 302         }
 303
 304         fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 305         pdev = parport_register_device (port, name, NULL,
 306                                         NULL, pp_irq, fl, pp);
 307         parport_put_port (port);
 308
 309         if (!pdev) {
 310                 printk (KERN_WARNING "%s: failed to register device!\n", name);
 311                 kfree (name);
 312                 return -ENXIO;
 313         }
 314
 315         pp->pdev = pdev;
 316         printk (KERN_DEBUG "%s: registered pardevice\n", name);
 317         return 0;
 318 }
 319
 320 static enum ieee1284_phase init_phase (int mode)
 321 {
 322         switch (mode & ~(IEEE1284_DEVICEID
 323                          | IEEE1284_ADDR)) {
 324         case IEEE1284_MODE_NIBBLE:
 325         case IEEE1284_MODE_BYTE:
 326                 return IEEE1284_PH_REV_IDLE;
 327         }
 328         return IEEE1284_PH_FWD_IDLE;
 329 }
 330
 331 static int pp_ioctl(struct inode *inode, struct file *file,
 332                     unsigned int cmd, unsigned long arg)
 333 {
 334         unsigned int minor = iminor(inode);
 335         struct pp_struct *pp = file->private_data;
 336         struct parport * port;
 337         void __user *argp = (void __user *)arg;
 338
 339         /* First handle the cases that don't take arguments. */
 340         switch (cmd) {
 341         case PPCLAIM:
 342             {
 343                 struct ieee1284_info *info;
 344                 int ret;
 345
 346                 if (pp->flags & PP_CLAIMED) {
 347                         printk (KERN_DEBUG CHRDEV
 348                                 "%x: you've already got it!\n", minor);
 349                         return -EINVAL;
 350                 }
 351
 352                 /* Deferred device registration. */
 353                 if (!pp->pdev) {
 354                         int err = register_device (minor, pp);
 355                         if (err) {
 356                                 return err;
 357                         }
 358                 }
 359
 360                 ret = parport_claim_or_block (pp->pdev);
 361                 if (ret < 0)
 362                         return ret;
 363
 364                 pp->flags |= PP_CLAIMED;
 365
 366                 /* For interrupt-reporting to work, we need to be
 367                  * informed of each interrupt. */
 368                 pp_enable_irq (pp);
 369
 370                 /* We may need to fix up the state machine. */
 371                 info = &pp->pdev->port->ieee1284;
 372                 pp->saved_state.mode = info->mode;
 373                 pp->saved_state.phase = info->phase;
 374                 info->mode = pp->state.mode;
 375                 info->phase = pp->state.phase;
 376                 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
 377                 parport_set_timeout (pp->pdev, pp->default_inactivity);
 378
 379                 return 0;
 380             }
 381         case PPEXCL:
 382                 if (pp->pdev) {
 383                         printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
 384                                 "already registered\n", minor);
 385                         if (pp->flags & PP_EXCL)
 386                                 /* But it's not really an error. */
 387                                 return 0;
 388                         /* There's no chance of making the driver happy. */
 389                         return -EINVAL;
 390                 }
 391
 392                 /* Just remember to register the device exclusively
 393                  * when we finally do the registration. */
 394                 pp->flags |= PP_EXCL;
 395                 return 0;
 396         case PPSETMODE:
 397             {
 398                 int mode;
 399                 if (copy_from_user (&mode, argp, sizeof (mode)))
 400                         return -EFAULT;
 401                 /* FIXME: validate mode */
 402                 pp->state.mode = mode;
 403                 pp->state.phase = init_phase (mode);
 404
 405                 if (pp->flags & PP_CLAIMED) {
 406                         pp->pdev->port->ieee1284.mode = mode;
 407                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 408                 }
 409
 410                 return 0;
 411             }
 412         case PPGETMODE:
 413             {
 414                 int mode;
 415
 416                 if (pp->flags & PP_CLAIMED) {
 417                         mode = pp->pdev->port->ieee1284.mode;
 418                 } else {
 419                         mode = pp->state.mode;
 420                 }
 421                 if (copy_to_user (argp, &mode, sizeof (mode))) {
 422                         return -EFAULT;
 423                 }
 424                 return 0;
 425             }
 426         case PPSETPHASE:
 427             {
 428                 int phase;
 429                 if (copy_from_user (&phase, argp, sizeof (phase))) {
 430                         return -EFAULT;
 431                 }
 432                 /* FIXME: validate phase */
 433                 pp->state.phase = phase;
 434
 435                 if (pp->flags & PP_CLAIMED) {
 436                         pp->pdev->port->ieee1284.phase = phase;
 437                 }
 438
 439                 return 0;
 440             }
 441         case PPGETPHASE:
 442             {
 443                 int phase;
 444
 445                 if (pp->flags & PP_CLAIMED) {
 446                         phase = pp->pdev->port->ieee1284.phase;
 447                 } else {
 448                         phase = pp->state.phase;
 449                 }
 450                 if (copy_to_user (argp, &phase, sizeof (phase))) {
 451                         return -EFAULT;
 452                 }
 453                 return 0;
 454             }
 455         case PPGETMODES:
 456             {
 457                 unsigned int modes;
 458
 459                 port = parport_find_number (minor);
 460                 if (!port)
 461                         return -ENODEV;
 462
 463                 modes = port->modes;
 464                 if (copy_to_user (argp, &modes, sizeof (modes))) {
 465                         return -EFAULT;
 466                 }
 467                 return 0;
 468             }
 469         case PPSETFLAGS:
 470             {
 471                 int uflags;
 472
 473                 if (copy_from_user (&uflags, argp, sizeof (uflags))) {
 474                         return -EFAULT;
 475                 }
 476                 pp->flags &= ~PP_FLAGMASK;
 477                 pp->flags |= (uflags & PP_FLAGMASK);
 478                 return 0;
 479             }
 480         case PPGETFLAGS:
 481             {
 482                 int uflags;
 483
 484                 uflags = pp->flags & PP_FLAGMASK;
 485                 if (copy_to_user (argp, &uflags, sizeof (uflags))) {
 486                         return -EFAULT;
 487                 }
 488                 return 0;
 489             }
 490         }       /* end switch() */
 491
 492         /* Everything else requires the port to be claimed, so check
 493          * that now. */
 494         if ((pp->flags & PP_CLAIMED) == 0) {
 495                 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
 496                         minor);
 497                 return -EINVAL;
 498         }
 499
 500         port = pp->pdev->port;
 501         switch (cmd) {
 502                 struct ieee1284_info *info;
 503                 unsigned char reg;
 504                 unsigned char mask;
 505                 int mode;
 506                 int ret;
 507                 struct timeval par_timeout;
 508                 long to_jiffies;
 509
 510         case PPRSTATUS:
 511                 reg = parport_read_status (port);
 512                 if (copy_to_user (argp, &reg, sizeof (reg)))
 513                         return -EFAULT;
 514                 return 0;
 515         case PPRDATA:
 516                 reg = parport_read_data (port);
 517                 if (copy_to_user (argp, &reg, sizeof (reg)))
 518                         return -EFAULT;
 519                 return 0;
 520         case PPRCONTROL:
 521                 reg = parport_read_control (port);
 522                 if (copy_to_user (argp, &reg, sizeof (reg)))
 523                         return -EFAULT;
 524                 return 0;
 525         case PPYIELD:
 526                 parport_yield_blocking (pp->pdev);
 527                 return 0;
 528
 529         case PPRELEASE:
 530                 /* Save the state machine's state. */
 531                 info = &pp->pdev->port->ieee1284;
 532                 pp->state.mode = info->mode;
 533                 pp->state.phase = info->phase;
 534                 info->mode = pp->saved_state.mode;
 535                 info->phase = pp->saved_state.phase;
 536                 parport_release (pp->pdev);
 537                 pp->flags &= ~PP_CLAIMED;
 538                 return 0;
 539
 540         case PPWCONTROL:
 541                 if (copy_from_user (&reg, argp, sizeof (reg)))
 542                         return -EFAULT;
 543                 parport_write_control (port, reg);
 544                 return 0;
 545
 546         case PPWDATA:
 547                 if (copy_from_user (&reg, argp, sizeof (reg)))
 548                         return -EFAULT;
 549                 parport_write_data (port, reg);
 550                 return 0;
 551
 552         case PPFCONTROL:
 553                 if (copy_from_user (&mask, argp,
 554                                     sizeof (mask)))
 555                         return -EFAULT;
 556                 if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
 557                                     sizeof (reg)))
 558                         return -EFAULT;
 559                 parport_frob_control (port, mask, reg);
 560                 return 0;
 561
 562         case PPDATADIR:
 563                 if (copy_from_user (&mode, argp, sizeof (mode)))
 564                         return -EFAULT;
 565                 if (mode)
 566                         port->ops->data_reverse (port);
 567                 else
 568                         port->ops->data_forward (port);
 569                 return 0;
 570
 571         case PPNEGOT:
 572                 if (copy_from_user (&mode, argp, sizeof (mode)))
 573                         return -EFAULT;
 574                 switch ((ret = parport_negotiate (port, mode))) {
 575                 case 0: break;
 576                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 577                         ret = -EIO;
 578                         break;
 579                 case 1:  /* handshake succeeded, peripheral rejected mode */
 580                         ret = -ENXIO;
 581                         break;
 582                 }
 583                 pp_enable_irq (pp);
 584                 return ret;
 585
 586         case PPWCTLONIRQ:
 587                 if (copy_from_user (&reg, argp, sizeof (reg)))
 588                         return -EFAULT;
 589
 590                 /* Remember what to set the control lines to, for next
 591                  * time we get an interrupt. */
 592                 pp->irqctl = reg;
 593                 pp->irqresponse = 1;
 594                 return 0;
 595
 596         case PPCLRIRQ:
 597                 ret = atomic_read (&pp->irqc);
 598                 if (copy_to_user (argp, &ret, sizeof (ret)))
 599                         return -EFAULT;
 600                 atomic_sub (ret, &pp->irqc);
 601                 return 0;
 602
 603         case PPSETTIME:
 604                 if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
 605                         return -EFAULT;
 606                 }
 607                 /* Convert to jiffies, place in pp->pdev->timeout */
 608                 if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
 609                         return -EINVAL;
 610                 }
 611                 to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
 612                 to_jiffies += par_timeout.tv_sec * (long)HZ;
 613                 if (to_jiffies <= 0) {
 614                         return -EINVAL;
 615                 }
 616                 pp->pdev->timeout = to_jiffies;
 617                 return 0;
 618
 619         case PPGETTIME:
 620                 to_jiffies = pp->pdev->timeout;
 621                 par_timeout.tv_sec = to_jiffies / HZ;
 622                 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
 623                 if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
 624                         return -EFAULT;
 625                 return 0;
 626
 627         default:
 628                 printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
 629                         cmd);
 630                 return -EINVAL;
 631         }
 632
 633         /* Keep the compiler happy */
 634         return 0;
 635 }
 636
 637 static int pp_open (struct inode * inode, struct file * file)
 638 {
 639         unsigned int minor = iminor(inode);
 640         struct pp_struct *pp;
 641
 642         if (minor >= PARPORT_MAX)
 643                 return -ENXIO;
 644
 645         pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
 646         if (!pp)
 647                 return -ENOMEM;
 648
 649         pp->state.mode = IEEE1284_MODE_COMPAT;
 650         pp->state.phase = init_phase (pp->state.mode);
 651         pp->flags = 0;
 652         pp->irqresponse = 0;
 653         atomic_set (&pp->irqc, 0);
 654         init_waitqueue_head (&pp->irq_wait);
 655
 656         /* Defer the actual device registration until the first claim.
 657          * That way, we know whether or not the driver wants to have
 658          * exclusive access to the port (PPEXCL).
 659          */
 660         pp->pdev = NULL;
 661         file->private_data = pp;
 662
 663         return 0;
 664 }
 665
 666 static int pp_release (struct inode * inode, struct file * file)
 667 {
 668         unsigned int minor = iminor(inode);
 669         struct pp_struct *pp = file->private_data;
 670         int compat_negot;
 671
 672         compat_negot = 0;
 673         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 674             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 675                 struct ieee1284_info *info;
 676
 677                 /* parport released, but not in compatibility mode */
 678                 parport_claim_or_block (pp->pdev);
 679                 pp->flags |= PP_CLAIMED;
 680                 info = &pp->pdev->port->ieee1284;
 681                 pp->saved_state.mode = info->mode;
 682                 pp->saved_state.phase = info->phase;
 683                 info->mode = pp->state.mode;
 684                 info->phase = pp->state.phase;
 685                 compat_negot = 1;
 686         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 687             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 688                 compat_negot = 2;
 689         }
 690         if (compat_negot) {
 691                 parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
 692                 printk (KERN_DEBUG CHRDEV
 693                         "%x: negotiated back to compatibility mode because "
 694                         "user-space forgot\n", minor);
 695         }
 696
 697         if (pp->flags & PP_CLAIMED) {
 698                 struct ieee1284_info *info;
 699
 700                 info = &pp->pdev->port->ieee1284;
 701                 pp->state.mode = info->mode;
 702                 pp->state.phase = info->phase;
 703                 info->mode = pp->saved_state.mode;
 704                 info->phase = pp->saved_state.phase;
 705                 parport_release (pp->pdev);
 706                 if (compat_negot != 1) {
 707                         printk (KERN_DEBUG CHRDEV "%x: released pardevice "
 708                                 "because user-space forgot\n", minor);
 709                 }
 710         }
 711
 712         if (pp->pdev) {
 713                 const char *name = pp->pdev->name;
 714                 parport_unregister_device (pp->pdev);
 715                 kfree (name);
 716                 pp->pdev = NULL;
 717                 printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
 718                         minor);
 719         }
 720
 721         kfree (pp);
 722
 723         return 0;
 724 }
 725
 726 /* No kernel lock held - fine */
 727 static unsigned int pp_poll (struct file * file, poll_table * wait)
 728 {
 729         struct pp_struct *pp = file->private_data;
 730         unsigned int mask = 0;
 731
 732         poll_wait (file, &pp->irq_wait, wait);
 733         if (atomic_read (&pp->irqc))
 734                 mask |= POLLIN | POLLRDNORM;
 735
 736         return mask;
 737 }
 738
 739 static struct class *ppdev_class;
 740
 741 static const struct file_operations pp_fops = {
 742         .owner          = THIS_MODULE,
 743         .llseek         = no_llseek,
 744         .read           = pp_read,
 745         .write          = pp_write,
 746         .poll           = pp_poll,
 747         .ioctl          = pp_ioctl,
 748         .open           = pp_open,
 749         .release        = pp_release,
 750 };
 751
 752 static void pp_attach(struct parport *port)
 753 {
 754         device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
 755                         "parport%d", port->number);
 756 }
 757
 758 static void pp_detach(struct parport *port)
 759 {
 760         device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 761 }
 762
 763 static struct parport_driver pp_driver = {
 764         .name           = CHRDEV,
 765         .attach         = pp_attach,
 766         .detach         = pp_detach,
 767 };
 768
 769 static int __init ppdev_init (void)
 770 {
 771         int err = 0;
 772
 773         if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
 774                 printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
 775                         PP_MAJOR);
 776                 return -EIO;
 777         }
 778         ppdev_class = class_create(THIS_MODULE, CHRDEV);
 779         if (IS_ERR(ppdev_class)) {
 780                 err = PTR_ERR(ppdev_class);
 781                 goto out_chrdev;
 782         }
 783         if (parport_register_driver(&pp_driver)) {
 784                 printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
 785                 goto out_class;
 786         }
 787
 788         printk (KERN_INFO PP_VERSION "\n");
 789         goto out;
 790
 791 out_class:
 792         class_destroy(ppdev_class);
 793 out_chrdev:
 794         unregister_chrdev(PP_MAJOR, CHRDEV);
 795 out:
 796         return err;
 797 }
 798
 799 static void __exit ppdev_cleanup (void)
 800 {
 801         /* Clean up all parport stuff */
 802         parport_unregister_driver(&pp_driver);
 803         class_destroy(ppdev_class);
 804         unregister_chrdev (PP_MAJOR, CHRDEV);
 805 }
 806
 807 module_init(ppdev_init);
 808 module_exit(ppdev_cleanup);
 809
 810 MODULE_LICENSE("GPL");
 811 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);