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 #include <linux/compat.h>
  73
  74 #define PP_VERSION "ppdev: user-space parallel port driver"
  75 #define CHRDEV "ppdev"
  76
  77 struct pp_struct {
  78         struct pardevice *pdev;
  79         wait_queue_head_t irq_wait;
  80         atomic_t irqc;
  81         unsigned int flags;
  82         int irqresponse;
  83         unsigned char irqctl;
  84         struct ieee1284_info state;
  85         struct ieee1284_info saved_state;
  86         long default_inactivity;
  87 };
  88
  89 /* should we use PARDEVICE_MAX here? */
  90 static struct device *devices[PARPORT_MAX];
  91
  92 /* pp_struct.flags bitfields */
  93 #define PP_CLAIMED    (1<<0)
  94 #define PP_EXCL       (1<<1)
  95
  96 /* Other constants */
  97 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
  98 #define PP_BUFFER_SIZE 1024
  99 #define PARDEVICE_MAX 8
 100
 101 /* ROUND_UP macro from fs/select.c */
 102 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
 103
 104 static DEFINE_MUTEX(pp_do_mutex);
 105
 106 /* define fixed sized ioctl cmd for y2038 migration */
 107 #define PPGETTIME32     _IOR(PP_IOCTL, 0x95, s32[2])
 108 #define PPSETTIME32     _IOW(PP_IOCTL, 0x96, s32[2])
 109 #define PPGETTIME64     _IOR(PP_IOCTL, 0x95, s64[2])
 110 #define PPSETTIME64     _IOW(PP_IOCTL, 0x96, s64[2])
 111
 112 static inline void pp_enable_irq(struct pp_struct *pp)
 113 {
 114         struct parport *port = pp->pdev->port;
 115
 116         port->ops->enable_irq(port);
 117 }
 118
 119 static ssize_t pp_read(struct file *file, char __user *buf, size_t count,
 120                        loff_t *ppos)
 121 {
 122         unsigned int minor = iminor(file_inode(file));
 123         struct pp_struct *pp = file->private_data;
 124         char *kbuffer;
 125         ssize_t bytes_read = 0;
 126         struct parport *pport;
 127         int mode;
 128
 129         if (!(pp->flags & PP_CLAIMED)) {
 130                 /* Don't have the port claimed */
 131                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 132                 return -EINVAL;
 133         }
 134
 135         /* Trivial case. */
 136         if (count == 0)
 137                 return 0;
 138
 139         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 140         if (!kbuffer)
 141                 return -ENOMEM;
 142         pport = pp->pdev->port;
 143         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 144
 145         parport_set_timeout(pp->pdev,
 146                             (file->f_flags & O_NONBLOCK) ?
 147                             PARPORT_INACTIVITY_O_NONBLOCK :
 148                             pp->default_inactivity);
 149
 150         while (bytes_read == 0) {
 151                 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
 152
 153                 if (mode == IEEE1284_MODE_EPP) {
 154                         /* various specials for EPP mode */
 155                         int flags = 0;
 156                         size_t (*fn)(struct parport *, void *, size_t, int);
 157
 158                         if (pp->flags & PP_W91284PIC)
 159                                 flags |= PARPORT_W91284PIC;
 160                         if (pp->flags & PP_FASTREAD)
 161                                 flags |= PARPORT_EPP_FAST;
 162                         if (pport->ieee1284.mode & IEEE1284_ADDR)
 163                                 fn = pport->ops->epp_read_addr;
 164                         else
 165                                 fn = pport->ops->epp_read_data;
 166                         bytes_read = (*fn)(pport, kbuffer, need, flags);
 167                 } else {
 168                         bytes_read = parport_read(pport, kbuffer, need);
 169                 }
 170
 171                 if (bytes_read != 0)
 172                         break;
 173
 174                 if (file->f_flags & O_NONBLOCK) {
 175                         bytes_read = -EAGAIN;
 176                         break;
 177                 }
 178
 179                 if (signal_pending(current)) {
 180                         bytes_read = -ERESTARTSYS;
 181                         break;
 182                 }
 183
 184                 cond_resched();
 185         }
 186
 187         parport_set_timeout(pp->pdev, pp->default_inactivity);
 188
 189         if (bytes_read > 0 && copy_to_user(buf, kbuffer, bytes_read))
 190                 bytes_read = -EFAULT;
 191
 192         kfree(kbuffer);
 193         pp_enable_irq(pp);
 194         return bytes_read;
 195 }
 196
 197 static ssize_t pp_write(struct file *file, const char __user *buf,
 198                         size_t count, loff_t *ppos)
 199 {
 200         unsigned int minor = iminor(file_inode(file));
 201         struct pp_struct *pp = file->private_data;
 202         char *kbuffer;
 203         ssize_t bytes_written = 0;
 204         ssize_t wrote;
 205         int mode;
 206         struct parport *pport;
 207
 208         if (!(pp->flags & PP_CLAIMED)) {
 209                 /* Don't have the port claimed */
 210                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 211                 return -EINVAL;
 212         }
 213
 214         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 215         if (!kbuffer)
 216                 return -ENOMEM;
 217
 218         pport = pp->pdev->port;
 219         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 220
 221         parport_set_timeout(pp->pdev,
 222                             (file->f_flags & O_NONBLOCK) ?
 223                             PARPORT_INACTIVITY_O_NONBLOCK :
 224                             pp->default_inactivity);
 225
 226         while (bytes_written < count) {
 227                 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
 228
 229                 if (copy_from_user(kbuffer, buf + bytes_written, n)) {
 230                         bytes_written = -EFAULT;
 231                         break;
 232                 }
 233
 234                 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
 235                         /* do a fast EPP write */
 236                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 237                                 wrote = pport->ops->epp_write_addr(pport,
 238                                         kbuffer, n, PARPORT_EPP_FAST);
 239                         } else {
 240                                 wrote = pport->ops->epp_write_data(pport,
 241                                         kbuffer, n, PARPORT_EPP_FAST);
 242                         }
 243                 } else {
 244                         wrote = parport_write(pp->pdev->port, kbuffer, n);
 245                 }
 246
 247                 if (wrote <= 0) {
 248                         if (!bytes_written)
 249                                 bytes_written = wrote;
 250                         break;
 251                 }
 252
 253                 bytes_written += wrote;
 254
 255                 if (file->f_flags & O_NONBLOCK) {
 256                         if (!bytes_written)
 257                                 bytes_written = -EAGAIN;
 258                         break;
 259                 }
 260
 261                 if (signal_pending(current))
 262                         break;
 263
 264                 cond_resched();
 265         }
 266
 267         parport_set_timeout(pp->pdev, pp->default_inactivity);
 268
 269         kfree(kbuffer);
 270         pp_enable_irq(pp);
 271         return bytes_written;
 272 }
 273
 274 static void pp_irq(void *private)
 275 {
 276         struct pp_struct *pp = private;
 277
 278         if (pp->irqresponse) {
 279                 parport_write_control(pp->pdev->port, pp->irqctl);
 280                 pp->irqresponse = 0;
 281         }
 282
 283         atomic_inc(&pp->irqc);
 284         wake_up_interruptible(&pp->irq_wait);
 285 }
 286
 287 static int register_device(int minor, struct pp_struct *pp)
 288 {
 289         struct parport *port;
 290         struct pardevice *pdev = NULL;
 291         char *name;
 292         struct pardev_cb ppdev_cb;
 293
 294         name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
 295         if (name == NULL)
 296                 return -ENOMEM;
 297
 298         port = parport_find_number(minor);
 299         if (!port) {
 300                 pr_warn("%s: no associated port!\n", name);
 301                 kfree(name);
 302                 return -ENXIO;
 303         }
 304
 305         memset(&ppdev_cb, 0, sizeof(ppdev_cb));
 306         ppdev_cb.irq_func = pp_irq;
 307         ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 308         ppdev_cb.private = pp;
 309         pdev = parport_register_dev_model(port, name, &ppdev_cb, minor);
 310         parport_put_port(port);
 311         kfree(name);
 312
 313         if (!pdev) {
 314                 pr_warn("%s: failed to register device!\n", name);
 315                 return -ENXIO;
 316         }
 317
 318         pp->pdev = pdev;
 319         dev_dbg(&pdev->dev, "registered pardevice\n");
 320         return 0;
 321 }
 322
 323 static enum ieee1284_phase init_phase(int mode)
 324 {
 325         switch (mode & ~(IEEE1284_DEVICEID
 326                          | IEEE1284_ADDR)) {
 327         case IEEE1284_MODE_NIBBLE:
 328         case IEEE1284_MODE_BYTE:
 329                 return IEEE1284_PH_REV_IDLE;
 330         }
 331         return IEEE1284_PH_FWD_IDLE;
 332 }
 333
 334 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
 335 {
 336         long to_jiffies;
 337
 338         if ((tv_sec < 0) || (tv_usec < 0))
 339                 return -EINVAL;
 340
 341         to_jiffies = usecs_to_jiffies(tv_usec);
 342         to_jiffies += tv_sec * HZ;
 343         if (to_jiffies <= 0)
 344                 return -EINVAL;
 345
 346         pdev->timeout = to_jiffies;
 347         return 0;
 348 }
 349
 350 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 351 {
 352         unsigned int minor = iminor(file_inode(file));
 353         struct pp_struct *pp = file->private_data;
 354         struct parport *port;
 355         void __user *argp = (void __user *)arg;
 356
 357         /* First handle the cases that don't take arguments. */
 358         switch (cmd) {
 359         case PPCLAIM:
 360             {
 361                 struct ieee1284_info *info;
 362                 int ret;
 363
 364                 if (pp->flags & PP_CLAIMED) {
 365                         dev_dbg(&pp->pdev->dev, "you've already got it!\n");
 366                         return -EINVAL;
 367                 }
 368
 369                 /* Deferred device registration. */
 370                 if (!pp->pdev) {
 371                         int err = register_device(minor, pp);
 372
 373                         if (err)
 374                                 return err;
 375                 }
 376
 377                 ret = parport_claim_or_block(pp->pdev);
 378                 if (ret < 0)
 379                         return ret;
 380
 381                 pp->flags |= PP_CLAIMED;
 382
 383                 /* For interrupt-reporting to work, we need to be
 384                  * informed of each interrupt. */
 385                 pp_enable_irq(pp);
 386
 387                 /* We may need to fix up the state machine. */
 388                 info = &pp->pdev->port->ieee1284;
 389                 pp->saved_state.mode = info->mode;
 390                 pp->saved_state.phase = info->phase;
 391                 info->mode = pp->state.mode;
 392                 info->phase = pp->state.phase;
 393                 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
 394                 parport_set_timeout(pp->pdev, pp->default_inactivity);
 395
 396                 return 0;
 397             }
 398         case PPEXCL:
 399                 if (pp->pdev) {
 400                         dev_dbg(&pp->pdev->dev,
 401                                 "too late for PPEXCL; already registered\n");
 402                         if (pp->flags & PP_EXCL)
 403                                 /* But it's not really an error. */
 404                                 return 0;
 405                         /* There's no chance of making the driver happy. */
 406                         return -EINVAL;
 407                 }
 408
 409                 /* Just remember to register the device exclusively
 410                  * when we finally do the registration. */
 411                 pp->flags |= PP_EXCL;
 412                 return 0;
 413         case PPSETMODE:
 414             {
 415                 int mode;
 416
 417                 if (copy_from_user(&mode, argp, sizeof(mode)))
 418                         return -EFAULT;
 419                 /* FIXME: validate mode */
 420                 pp->state.mode = mode;
 421                 pp->state.phase = init_phase(mode);
 422
 423                 if (pp->flags & PP_CLAIMED) {
 424                         pp->pdev->port->ieee1284.mode = mode;
 425                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 426                 }
 427
 428                 return 0;
 429             }
 430         case PPGETMODE:
 431             {
 432                 int mode;
 433
 434                 if (pp->flags & PP_CLAIMED)
 435                         mode = pp->pdev->port->ieee1284.mode;
 436                 else
 437                         mode = pp->state.mode;
 438
 439                 if (copy_to_user(argp, &mode, sizeof(mode)))
 440                         return -EFAULT;
 441                 return 0;
 442             }
 443         case PPSETPHASE:
 444             {
 445                 int phase;
 446
 447                 if (copy_from_user(&phase, argp, sizeof(phase)))
 448                         return -EFAULT;
 449
 450                 /* FIXME: validate phase */
 451                 pp->state.phase = phase;
 452
 453                 if (pp->flags & PP_CLAIMED)
 454                         pp->pdev->port->ieee1284.phase = phase;
 455
 456                 return 0;
 457             }
 458         case PPGETPHASE:
 459             {
 460                 int phase;
 461
 462                 if (pp->flags & PP_CLAIMED)
 463                         phase = pp->pdev->port->ieee1284.phase;
 464                 else
 465                         phase = pp->state.phase;
 466                 if (copy_to_user(argp, &phase, sizeof(phase)))
 467                         return -EFAULT;
 468                 return 0;
 469             }
 470         case PPGETMODES:
 471             {
 472                 unsigned int modes;
 473
 474                 port = parport_find_number(minor);
 475                 if (!port)
 476                         return -ENODEV;
 477
 478                 modes = port->modes;
 479                 parport_put_port(port);
 480                 if (copy_to_user(argp, &modes, sizeof(modes)))
 481                         return -EFAULT;
 482                 return 0;
 483             }
 484         case PPSETFLAGS:
 485             {
 486                 int uflags;
 487
 488                 if (copy_from_user(&uflags, argp, sizeof(uflags)))
 489                         return -EFAULT;
 490                 pp->flags &= ~PP_FLAGMASK;
 491                 pp->flags |= (uflags & PP_FLAGMASK);
 492                 return 0;
 493             }
 494         case PPGETFLAGS:
 495             {
 496                 int uflags;
 497
 498                 uflags = pp->flags & PP_FLAGMASK;
 499                 if (copy_to_user(argp, &uflags, sizeof(uflags)))
 500                         return -EFAULT;
 501                 return 0;
 502             }
 503         }       /* end switch() */
 504
 505         /* Everything else requires the port to be claimed, so check
 506          * that now. */
 507         if ((pp->flags & PP_CLAIMED) == 0) {
 508                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 509                 return -EINVAL;
 510         }
 511
 512         port = pp->pdev->port;
 513         switch (cmd) {
 514                 struct ieee1284_info *info;
 515                 unsigned char reg;
 516                 unsigned char mask;
 517                 int mode;
 518                 s32 time32[2];
 519                 s64 time64[2];
 520                 struct timespec64 ts;
 521                 int ret;
 522
 523         case PPRSTATUS:
 524                 reg = parport_read_status(port);
 525                 if (copy_to_user(argp, &reg, sizeof(reg)))
 526                         return -EFAULT;
 527                 return 0;
 528         case PPRDATA:
 529                 reg = parport_read_data(port);
 530                 if (copy_to_user(argp, &reg, sizeof(reg)))
 531                         return -EFAULT;
 532                 return 0;
 533         case PPRCONTROL:
 534                 reg = parport_read_control(port);
 535                 if (copy_to_user(argp, &reg, sizeof(reg)))
 536                         return -EFAULT;
 537                 return 0;
 538         case PPYIELD:
 539                 parport_yield_blocking(pp->pdev);
 540                 return 0;
 541
 542         case PPRELEASE:
 543                 /* Save the state machine's state. */
 544                 info = &pp->pdev->port->ieee1284;
 545                 pp->state.mode = info->mode;
 546                 pp->state.phase = info->phase;
 547                 info->mode = pp->saved_state.mode;
 548                 info->phase = pp->saved_state.phase;
 549                 parport_release(pp->pdev);
 550                 pp->flags &= ~PP_CLAIMED;
 551                 return 0;
 552
 553         case PPWCONTROL:
 554                 if (copy_from_user(&reg, argp, sizeof(reg)))
 555                         return -EFAULT;
 556                 parport_write_control(port, reg);
 557                 return 0;
 558
 559         case PPWDATA:
 560                 if (copy_from_user(&reg, argp, sizeof(reg)))
 561                         return -EFAULT;
 562                 parport_write_data(port, reg);
 563                 return 0;
 564
 565         case PPFCONTROL:
 566                 if (copy_from_user(&mask, argp,
 567                                    sizeof(mask)))
 568                         return -EFAULT;
 569                 if (copy_from_user(&reg, 1 + (unsigned char __user *) arg,
 570                                    sizeof(reg)))
 571                         return -EFAULT;
 572                 parport_frob_control(port, mask, reg);
 573                 return 0;
 574
 575         case PPDATADIR:
 576                 if (copy_from_user(&mode, argp, sizeof(mode)))
 577                         return -EFAULT;
 578                 if (mode)
 579                         port->ops->data_reverse(port);
 580                 else
 581                         port->ops->data_forward(port);
 582                 return 0;
 583
 584         case PPNEGOT:
 585                 if (copy_from_user(&mode, argp, sizeof(mode)))
 586                         return -EFAULT;
 587                 switch ((ret = parport_negotiate(port, mode))) {
 588                 case 0: break;
 589                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 590                         ret = -EIO;
 591                         break;
 592                 case 1:  /* handshake succeeded, peripheral rejected mode */
 593                         ret = -ENXIO;
 594                         break;
 595                 }
 596                 pp_enable_irq(pp);
 597                 return ret;
 598
 599         case PPWCTLONIRQ:
 600                 if (copy_from_user(&reg, argp, sizeof(reg)))
 601                         return -EFAULT;
 602
 603                 /* Remember what to set the control lines to, for next
 604                  * time we get an interrupt. */
 605                 pp->irqctl = reg;
 606                 pp->irqresponse = 1;
 607                 return 0;
 608
 609         case PPCLRIRQ:
 610                 ret = atomic_read(&pp->irqc);
 611                 if (copy_to_user(argp, &ret, sizeof(ret)))
 612                         return -EFAULT;
 613                 atomic_sub(ret, &pp->irqc);
 614                 return 0;
 615
 616         case PPSETTIME32:
 617                 if (copy_from_user(time32, argp, sizeof(time32)))
 618                         return -EFAULT;
 619
 620                 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
 621
 622         case PPSETTIME64:
 623                 if (copy_from_user(time64, argp, sizeof(time64)))
 624                         return -EFAULT;
 625
 626                 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
 627
 628         case PPGETTIME32:
 629                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 630                 time32[0] = ts.tv_sec;
 631                 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
 632                 if ((time32[0] < 0) || (time32[1] < 0))
 633                         return -EINVAL;
 634
 635                 if (copy_to_user(argp, time32, sizeof(time32)))
 636                         return -EFAULT;
 637
 638                 return 0;
 639
 640         case PPGETTIME64:
 641                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 642                 time64[0] = ts.tv_sec;
 643                 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
 644                 if ((time64[0] < 0) || (time64[1] < 0))
 645                         return -EINVAL;
 646
 647                 if (copy_to_user(argp, time64, sizeof(time64)))
 648                         return -EFAULT;
 649
 650                 return 0;
 651
 652         default:
 653                 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
 654                 return -EINVAL;
 655         }
 656
 657         /* Keep the compiler happy */
 658         return 0;
 659 }
 660
 661 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 662 {
 663         long ret;
 664
 665         mutex_lock(&pp_do_mutex);
 666         ret = pp_do_ioctl(file, cmd, arg);
 667         mutex_unlock(&pp_do_mutex);
 668         return ret;
 669 }
 670
 671 #ifdef CONFIG_COMPAT
 672 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
 673                             unsigned long arg)
 674 {
 675         return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 676 }
 677 #endif
 678
 679 static int pp_open(struct inode *inode, struct file *file)
 680 {
 681         unsigned int minor = iminor(inode);
 682         struct pp_struct *pp;
 683
 684         if (minor >= PARPORT_MAX)
 685                 return -ENXIO;
 686
 687         pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
 688         if (!pp)
 689                 return -ENOMEM;
 690
 691         pp->state.mode = IEEE1284_MODE_COMPAT;
 692         pp->state.phase = init_phase(pp->state.mode);
 693         pp->flags = 0;
 694         pp->irqresponse = 0;
 695         atomic_set(&pp->irqc, 0);
 696         init_waitqueue_head(&pp->irq_wait);
 697
 698         /* Defer the actual device registration until the first claim.
 699          * That way, we know whether or not the driver wants to have
 700          * exclusive access to the port (PPEXCL).
 701          */
 702         pp->pdev = NULL;
 703         file->private_data = pp;
 704
 705         return 0;
 706 }
 707
 708 static int pp_release(struct inode *inode, struct file *file)
 709 {
 710         unsigned int minor = iminor(inode);
 711         struct pp_struct *pp = file->private_data;
 712         int compat_negot;
 713
 714         compat_negot = 0;
 715         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 716             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 717                 struct ieee1284_info *info;
 718
 719                 /* parport released, but not in compatibility mode */
 720                 parport_claim_or_block(pp->pdev);
 721                 pp->flags |= PP_CLAIMED;
 722                 info = &pp->pdev->port->ieee1284;
 723                 pp->saved_state.mode = info->mode;
 724                 pp->saved_state.phase = info->phase;
 725                 info->mode = pp->state.mode;
 726                 info->phase = pp->state.phase;
 727                 compat_negot = 1;
 728         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 729             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 730                 compat_negot = 2;
 731         }
 732         if (compat_negot) {
 733                 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
 734                 dev_dbg(&pp->pdev->dev,
 735                         "negotiated back to compatibility mode because user-space forgot\n");
 736         }
 737
 738         if (pp->flags & PP_CLAIMED) {
 739                 struct ieee1284_info *info;
 740
 741                 info = &pp->pdev->port->ieee1284;
 742                 pp->state.mode = info->mode;
 743                 pp->state.phase = info->phase;
 744                 info->mode = pp->saved_state.mode;
 745                 info->phase = pp->saved_state.phase;
 746                 parport_release(pp->pdev);
 747                 if (compat_negot != 1) {
 748                         pr_debug(CHRDEV "%x: released pardevice "
 749                                 "because user-space forgot\n", minor);
 750                 }
 751         }
 752
 753         if (pp->pdev) {
 754                 parport_unregister_device(pp->pdev);
 755                 pp->pdev = NULL;
 756                 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 757         }
 758
 759         kfree(pp);
 760
 761         return 0;
 762 }
 763
 764 /* No kernel lock held - fine */
 765 static unsigned int pp_poll(struct file *file, poll_table *wait)
 766 {
 767         struct pp_struct *pp = file->private_data;
 768         unsigned int mask = 0;
 769
 770         poll_wait(file, &pp->irq_wait, wait);
 771         if (atomic_read(&pp->irqc))
 772                 mask |= POLLIN | POLLRDNORM;
 773
 774         return mask;
 775 }
 776
 777 static struct class *ppdev_class;
 778
 779 static const struct file_operations pp_fops = {
 780         .owner          = THIS_MODULE,
 781         .llseek         = no_llseek,
 782         .read           = pp_read,
 783         .write          = pp_write,
 784         .poll           = pp_poll,
 785         .unlocked_ioctl = pp_ioctl,
 786 #ifdef CONFIG_COMPAT
 787         .compat_ioctl   = pp_compat_ioctl,
 788 #endif
 789         .open           = pp_open,
 790         .release        = pp_release,
 791 };
 792
 793 static void pp_attach(struct parport *port)
 794 {
 795         struct device *ret;
 796
 797         if (devices[port->number])
 798                 return;
 799
 800         ret = device_create(ppdev_class, port->dev,
 801                             MKDEV(PP_MAJOR, port->number), NULL,
 802                             "parport%d", port->number);
 803         if (IS_ERR(ret)) {
 804                 pr_err("Failed to create device parport%d\n",
 805                        port->number);
 806                 return;
 807         }
 808         devices[port->number] = ret;
 809 }
 810
 811 static void pp_detach(struct parport *port)
 812 {
 813         if (!devices[port->number])
 814                 return;
 815
 816         device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 817         devices[port->number] = NULL;
 818 }
 819
 820 static int pp_probe(struct pardevice *par_dev)
 821 {
 822         struct device_driver *drv = par_dev->dev.driver;
 823         int len = strlen(drv->name);
 824
 825         if (strncmp(par_dev->name, drv->name, len))
 826                 return -ENODEV;
 827
 828         return 0;
 829 }
 830
 831 static struct parport_driver pp_driver = {
 832         .name           = CHRDEV,
 833         .probe          = pp_probe,
 834         .match_port     = pp_attach,
 835         .detach         = pp_detach,
 836         .devmodel       = true,
 837 };
 838
 839 static int __init ppdev_init(void)
 840 {
 841         int err = 0;
 842
 843         if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
 844                 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
 845                 return -EIO;
 846         }
 847         ppdev_class = class_create(THIS_MODULE, CHRDEV);
 848         if (IS_ERR(ppdev_class)) {
 849                 err = PTR_ERR(ppdev_class);
 850                 goto out_chrdev;
 851         }
 852         err = parport_register_driver(&pp_driver);
 853         if (err < 0) {
 854                 pr_warn(CHRDEV ": unable to register with parport\n");
 855                 goto out_class;
 856         }
 857
 858         pr_info(PP_VERSION "\n");
 859         goto out;
 860
 861 out_class:
 862         class_destroy(ppdev_class);
 863 out_chrdev:
 864         unregister_chrdev(PP_MAJOR, CHRDEV);
 865 out:
 866         return err;
 867 }
 868
 869 static void __exit ppdev_cleanup(void)
 870 {
 871         /* Clean up all parport stuff */
 872         parport_unregister_driver(&pp_driver);
 873         class_destroy(ppdev_class);
 874         unregister_chrdev(PP_MAJOR, CHRDEV);
 875 }
 876
 877 module_init(ppdev_init);
 878 module_exit(ppdev_cleanup);
 879
 880 MODULE_LICENSE("GPL");
 881 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);