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/signal.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         int index;
  88 };
  89
  90 /* should we use PARDEVICE_MAX here? */
  91 static struct device *devices[PARPORT_MAX];
  92
  93 static DEFINE_IDA(ida_index);
  94
  95 /* pp_struct.flags bitfields */
  96 #define PP_CLAIMED    (1<<0)
  97 #define PP_EXCL       (1<<1)
  98
  99 /* Other constants */
 100 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
 101 #define PP_BUFFER_SIZE 1024
 102 #define PARDEVICE_MAX 8
 103
 104 /* ROUND_UP macro from fs/select.c */
 105 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
 106
 107 static DEFINE_MUTEX(pp_do_mutex);
 108
 109 /* define fixed sized ioctl cmd for y2038 migration */
 110 #define PPGETTIME32     _IOR(PP_IOCTL, 0x95, s32[2])
 111 #define PPSETTIME32     _IOW(PP_IOCTL, 0x96, s32[2])
 112 #define PPGETTIME64     _IOR(PP_IOCTL, 0x95, s64[2])
 113 #define PPSETTIME64     _IOW(PP_IOCTL, 0x96, s64[2])
 114
 115 static inline void pp_enable_irq(struct pp_struct *pp)
 116 {
 117         struct parport *port = pp->pdev->port;
 118
 119         port->ops->enable_irq(port);
 120 }
 121
 122 static ssize_t pp_read(struct file *file, char __user *buf, size_t count,
 123                        loff_t *ppos)
 124 {
 125         unsigned int minor = iminor(file_inode(file));
 126         struct pp_struct *pp = file->private_data;
 127         char *kbuffer;
 128         ssize_t bytes_read = 0;
 129         struct parport *pport;
 130         int mode;
 131
 132         if (!(pp->flags & PP_CLAIMED)) {
 133                 /* Don't have the port claimed */
 134                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 135                 return -EINVAL;
 136         }
 137
 138         /* Trivial case. */
 139         if (count == 0)
 140                 return 0;
 141
 142         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 143         if (!kbuffer)
 144                 return -ENOMEM;
 145         pport = pp->pdev->port;
 146         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 147
 148         parport_set_timeout(pp->pdev,
 149                             (file->f_flags & O_NONBLOCK) ?
 150                             PARPORT_INACTIVITY_O_NONBLOCK :
 151                             pp->default_inactivity);
 152
 153         while (bytes_read == 0) {
 154                 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
 155
 156                 if (mode == IEEE1284_MODE_EPP) {
 157                         /* various specials for EPP mode */
 158                         int flags = 0;
 159                         size_t (*fn)(struct parport *, void *, size_t, int);
 160
 161                         if (pp->flags & PP_W91284PIC)
 162                                 flags |= PARPORT_W91284PIC;
 163                         if (pp->flags & PP_FASTREAD)
 164                                 flags |= PARPORT_EPP_FAST;
 165                         if (pport->ieee1284.mode & IEEE1284_ADDR)
 166                                 fn = pport->ops->epp_read_addr;
 167                         else
 168                                 fn = pport->ops->epp_read_data;
 169                         bytes_read = (*fn)(pport, kbuffer, need, flags);
 170                 } else {
 171                         bytes_read = parport_read(pport, kbuffer, need);
 172                 }
 173
 174                 if (bytes_read != 0)
 175                         break;
 176
 177                 if (file->f_flags & O_NONBLOCK) {
 178                         bytes_read = -EAGAIN;
 179                         break;
 180                 }
 181
 182                 if (signal_pending(current)) {
 183                         bytes_read = -ERESTARTSYS;
 184                         break;
 185                 }
 186
 187                 cond_resched();
 188         }
 189
 190         parport_set_timeout(pp->pdev, pp->default_inactivity);
 191
 192         if (bytes_read > 0 && copy_to_user(buf, kbuffer, bytes_read))
 193                 bytes_read = -EFAULT;
 194
 195         kfree(kbuffer);
 196         pp_enable_irq(pp);
 197         return bytes_read;
 198 }
 199
 200 static ssize_t pp_write(struct file *file, const char __user *buf,
 201                         size_t count, loff_t *ppos)
 202 {
 203         unsigned int minor = iminor(file_inode(file));
 204         struct pp_struct *pp = file->private_data;
 205         char *kbuffer;
 206         ssize_t bytes_written = 0;
 207         ssize_t wrote;
 208         int mode;
 209         struct parport *pport;
 210
 211         if (!(pp->flags & PP_CLAIMED)) {
 212                 /* Don't have the port claimed */
 213                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 214                 return -EINVAL;
 215         }
 216
 217         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 218         if (!kbuffer)
 219                 return -ENOMEM;
 220
 221         pport = pp->pdev->port;
 222         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 223
 224         parport_set_timeout(pp->pdev,
 225                             (file->f_flags & O_NONBLOCK) ?
 226                             PARPORT_INACTIVITY_O_NONBLOCK :
 227                             pp->default_inactivity);
 228
 229         while (bytes_written < count) {
 230                 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
 231
 232                 if (copy_from_user(kbuffer, buf + bytes_written, n)) {
 233                         bytes_written = -EFAULT;
 234                         break;
 235                 }
 236
 237                 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
 238                         /* do a fast EPP write */
 239                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 240                                 wrote = pport->ops->epp_write_addr(pport,
 241                                         kbuffer, n, PARPORT_EPP_FAST);
 242                         } else {
 243                                 wrote = pport->ops->epp_write_data(pport,
 244                                         kbuffer, n, PARPORT_EPP_FAST);
 245                         }
 246                 } else {
 247                         wrote = parport_write(pp->pdev->port, kbuffer, n);
 248                 }
 249
 250                 if (wrote <= 0) {
 251                         if (!bytes_written)
 252                                 bytes_written = wrote;
 253                         break;
 254                 }
 255
 256                 bytes_written += wrote;
 257
 258                 if (file->f_flags & O_NONBLOCK) {
 259                         if (!bytes_written)
 260                                 bytes_written = -EAGAIN;
 261                         break;
 262                 }
 263
 264                 if (signal_pending(current))
 265                         break;
 266
 267                 cond_resched();
 268         }
 269
 270         parport_set_timeout(pp->pdev, pp->default_inactivity);
 271
 272         kfree(kbuffer);
 273         pp_enable_irq(pp);
 274         return bytes_written;
 275 }
 276
 277 static void pp_irq(void *private)
 278 {
 279         struct pp_struct *pp = private;
 280
 281         if (pp->irqresponse) {
 282                 parport_write_control(pp->pdev->port, pp->irqctl);
 283                 pp->irqresponse = 0;
 284         }
 285
 286         atomic_inc(&pp->irqc);
 287         wake_up_interruptible(&pp->irq_wait);
 288 }
 289
 290 static int register_device(int minor, struct pp_struct *pp)
 291 {
 292         struct parport *port;
 293         struct pardevice *pdev = NULL;
 294         char *name;
 295         struct pardev_cb ppdev_cb;
 296         int rc = 0, index;
 297
 298         name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
 299         if (name == NULL)
 300                 return -ENOMEM;
 301
 302         port = parport_find_number(minor);
 303         if (!port) {
 304                 pr_warn("%s: no associated port!\n", name);
 305                 rc = -ENXIO;
 306                 goto err;
 307         }
 308
 309         index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
 310         memset(&ppdev_cb, 0, sizeof(ppdev_cb));
 311         ppdev_cb.irq_func = pp_irq;
 312         ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 313         ppdev_cb.private = pp;
 314         pdev = parport_register_dev_model(port, name, &ppdev_cb, index);
 315         parport_put_port(port);
 316
 317         if (!pdev) {
 318                 pr_warn("%s: failed to register device!\n", name);
 319                 rc = -ENXIO;
 320                 ida_simple_remove(&ida_index, index);
 321                 goto err;
 322         }
 323
 324         pp->pdev = pdev;
 325         pp->index = index;
 326         dev_dbg(&pdev->dev, "registered pardevice\n");
 327 err:
 328         kfree(name);
 329         return rc;
 330 }
 331
 332 static enum ieee1284_phase init_phase(int mode)
 333 {
 334         switch (mode & ~(IEEE1284_DEVICEID
 335                          | IEEE1284_ADDR)) {
 336         case IEEE1284_MODE_NIBBLE:
 337         case IEEE1284_MODE_BYTE:
 338                 return IEEE1284_PH_REV_IDLE;
 339         }
 340         return IEEE1284_PH_FWD_IDLE;
 341 }
 342
 343 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
 344 {
 345         long to_jiffies;
 346
 347         if ((tv_sec < 0) || (tv_usec < 0))
 348                 return -EINVAL;
 349
 350         to_jiffies = usecs_to_jiffies(tv_usec);
 351         to_jiffies += tv_sec * HZ;
 352         if (to_jiffies <= 0)
 353                 return -EINVAL;
 354
 355         pdev->timeout = to_jiffies;
 356         return 0;
 357 }
 358
 359 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 360 {
 361         unsigned int minor = iminor(file_inode(file));
 362         struct pp_struct *pp = file->private_data;
 363         struct parport *port;
 364         void __user *argp = (void __user *)arg;
 365
 366         /* First handle the cases that don't take arguments. */
 367         switch (cmd) {
 368         case PPCLAIM:
 369             {
 370                 struct ieee1284_info *info;
 371                 int ret;
 372
 373                 if (pp->flags & PP_CLAIMED) {
 374                         dev_dbg(&pp->pdev->dev, "you've already got it!\n");
 375                         return -EINVAL;
 376                 }
 377
 378                 /* Deferred device registration. */
 379                 if (!pp->pdev) {
 380                         int err = register_device(minor, pp);
 381
 382                         if (err)
 383                                 return err;
 384                 }
 385
 386                 ret = parport_claim_or_block(pp->pdev);
 387                 if (ret < 0)
 388                         return ret;
 389
 390                 pp->flags |= PP_CLAIMED;
 391
 392                 /* For interrupt-reporting to work, we need to be
 393                  * informed of each interrupt. */
 394                 pp_enable_irq(pp);
 395
 396                 /* We may need to fix up the state machine. */
 397                 info = &pp->pdev->port->ieee1284;
 398                 pp->saved_state.mode = info->mode;
 399                 pp->saved_state.phase = info->phase;
 400                 info->mode = pp->state.mode;
 401                 info->phase = pp->state.phase;
 402                 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
 403                 parport_set_timeout(pp->pdev, pp->default_inactivity);
 404
 405                 return 0;
 406             }
 407         case PPEXCL:
 408                 if (pp->pdev) {
 409                         dev_dbg(&pp->pdev->dev,
 410                                 "too late for PPEXCL; already registered\n");
 411                         if (pp->flags & PP_EXCL)
 412                                 /* But it's not really an error. */
 413                                 return 0;
 414                         /* There's no chance of making the driver happy. */
 415                         return -EINVAL;
 416                 }
 417
 418                 /* Just remember to register the device exclusively
 419                  * when we finally do the registration. */
 420                 pp->flags |= PP_EXCL;
 421                 return 0;
 422         case PPSETMODE:
 423             {
 424                 int mode;
 425
 426                 if (copy_from_user(&mode, argp, sizeof(mode)))
 427                         return -EFAULT;
 428                 /* FIXME: validate mode */
 429                 pp->state.mode = mode;
 430                 pp->state.phase = init_phase(mode);
 431
 432                 if (pp->flags & PP_CLAIMED) {
 433                         pp->pdev->port->ieee1284.mode = mode;
 434                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 435                 }
 436
 437                 return 0;
 438             }
 439         case PPGETMODE:
 440             {
 441                 int mode;
 442
 443                 if (pp->flags & PP_CLAIMED)
 444                         mode = pp->pdev->port->ieee1284.mode;
 445                 else
 446                         mode = pp->state.mode;
 447
 448                 if (copy_to_user(argp, &mode, sizeof(mode)))
 449                         return -EFAULT;
 450                 return 0;
 451             }
 452         case PPSETPHASE:
 453             {
 454                 int phase;
 455
 456                 if (copy_from_user(&phase, argp, sizeof(phase)))
 457                         return -EFAULT;
 458
 459                 /* FIXME: validate phase */
 460                 pp->state.phase = phase;
 461
 462                 if (pp->flags & PP_CLAIMED)
 463                         pp->pdev->port->ieee1284.phase = phase;
 464
 465                 return 0;
 466             }
 467         case PPGETPHASE:
 468             {
 469                 int phase;
 470
 471                 if (pp->flags & PP_CLAIMED)
 472                         phase = pp->pdev->port->ieee1284.phase;
 473                 else
 474                         phase = pp->state.phase;
 475                 if (copy_to_user(argp, &phase, sizeof(phase)))
 476                         return -EFAULT;
 477                 return 0;
 478             }
 479         case PPGETMODES:
 480             {
 481                 unsigned int modes;
 482
 483                 port = parport_find_number(minor);
 484                 if (!port)
 485                         return -ENODEV;
 486
 487                 modes = port->modes;
 488                 parport_put_port(port);
 489                 if (copy_to_user(argp, &modes, sizeof(modes)))
 490                         return -EFAULT;
 491                 return 0;
 492             }
 493         case PPSETFLAGS:
 494             {
 495                 int uflags;
 496
 497                 if (copy_from_user(&uflags, argp, sizeof(uflags)))
 498                         return -EFAULT;
 499                 pp->flags &= ~PP_FLAGMASK;
 500                 pp->flags |= (uflags & PP_FLAGMASK);
 501                 return 0;
 502             }
 503         case PPGETFLAGS:
 504             {
 505                 int uflags;
 506
 507                 uflags = pp->flags & PP_FLAGMASK;
 508                 if (copy_to_user(argp, &uflags, sizeof(uflags)))
 509                         return -EFAULT;
 510                 return 0;
 511             }
 512         }       /* end switch() */
 513
 514         /* Everything else requires the port to be claimed, so check
 515          * that now. */
 516         if ((pp->flags & PP_CLAIMED) == 0) {
 517                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 518                 return -EINVAL;
 519         }
 520
 521         port = pp->pdev->port;
 522         switch (cmd) {
 523                 struct ieee1284_info *info;
 524                 unsigned char reg;
 525                 unsigned char mask;
 526                 int mode;
 527                 s32 time32[2];
 528                 s64 time64[2];
 529                 struct timespec64 ts;
 530                 int ret;
 531
 532         case PPRSTATUS:
 533                 reg = parport_read_status(port);
 534                 if (copy_to_user(argp, &reg, sizeof(reg)))
 535                         return -EFAULT;
 536                 return 0;
 537         case PPRDATA:
 538                 reg = parport_read_data(port);
 539                 if (copy_to_user(argp, &reg, sizeof(reg)))
 540                         return -EFAULT;
 541                 return 0;
 542         case PPRCONTROL:
 543                 reg = parport_read_control(port);
 544                 if (copy_to_user(argp, &reg, sizeof(reg)))
 545                         return -EFAULT;
 546                 return 0;
 547         case PPYIELD:
 548                 parport_yield_blocking(pp->pdev);
 549                 return 0;
 550
 551         case PPRELEASE:
 552                 /* Save the state machine's state. */
 553                 info = &pp->pdev->port->ieee1284;
 554                 pp->state.mode = info->mode;
 555                 pp->state.phase = info->phase;
 556                 info->mode = pp->saved_state.mode;
 557                 info->phase = pp->saved_state.phase;
 558                 parport_release(pp->pdev);
 559                 pp->flags &= ~PP_CLAIMED;
 560                 return 0;
 561
 562         case PPWCONTROL:
 563                 if (copy_from_user(&reg, argp, sizeof(reg)))
 564                         return -EFAULT;
 565                 parport_write_control(port, reg);
 566                 return 0;
 567
 568         case PPWDATA:
 569                 if (copy_from_user(&reg, argp, sizeof(reg)))
 570                         return -EFAULT;
 571                 parport_write_data(port, reg);
 572                 return 0;
 573
 574         case PPFCONTROL:
 575                 if (copy_from_user(&mask, argp,
 576                                    sizeof(mask)))
 577                         return -EFAULT;
 578                 if (copy_from_user(&reg, 1 + (unsigned char __user *) arg,
 579                                    sizeof(reg)))
 580                         return -EFAULT;
 581                 parport_frob_control(port, mask, reg);
 582                 return 0;
 583
 584         case PPDATADIR:
 585                 if (copy_from_user(&mode, argp, sizeof(mode)))
 586                         return -EFAULT;
 587                 if (mode)
 588                         port->ops->data_reverse(port);
 589                 else
 590                         port->ops->data_forward(port);
 591                 return 0;
 592
 593         case PPNEGOT:
 594                 if (copy_from_user(&mode, argp, sizeof(mode)))
 595                         return -EFAULT;
 596                 switch ((ret = parport_negotiate(port, mode))) {
 597                 case 0: break;
 598                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 599                         ret = -EIO;
 600                         break;
 601                 case 1:  /* handshake succeeded, peripheral rejected mode */
 602                         ret = -ENXIO;
 603                         break;
 604                 }
 605                 pp_enable_irq(pp);
 606                 return ret;
 607
 608         case PPWCTLONIRQ:
 609                 if (copy_from_user(&reg, argp, sizeof(reg)))
 610                         return -EFAULT;
 611
 612                 /* Remember what to set the control lines to, for next
 613                  * time we get an interrupt. */
 614                 pp->irqctl = reg;
 615                 pp->irqresponse = 1;
 616                 return 0;
 617
 618         case PPCLRIRQ:
 619                 ret = atomic_read(&pp->irqc);
 620                 if (copy_to_user(argp, &ret, sizeof(ret)))
 621                         return -EFAULT;
 622                 atomic_sub(ret, &pp->irqc);
 623                 return 0;
 624
 625         case PPSETTIME32:
 626                 if (copy_from_user(time32, argp, sizeof(time32)))
 627                         return -EFAULT;
 628
 629                 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
 630
 631         case PPSETTIME64:
 632                 if (copy_from_user(time64, argp, sizeof(time64)))
 633                         return -EFAULT;
 634
 635                 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
 636
 637         case PPGETTIME32:
 638                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 639                 time32[0] = ts.tv_sec;
 640                 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
 641                 if ((time32[0] < 0) || (time32[1] < 0))
 642                         return -EINVAL;
 643
 644                 if (copy_to_user(argp, time32, sizeof(time32)))
 645                         return -EFAULT;
 646
 647                 return 0;
 648
 649         case PPGETTIME64:
 650                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 651                 time64[0] = ts.tv_sec;
 652                 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
 653                 if ((time64[0] < 0) || (time64[1] < 0))
 654                         return -EINVAL;
 655
 656                 if (copy_to_user(argp, time64, sizeof(time64)))
 657                         return -EFAULT;
 658
 659                 return 0;
 660
 661         default:
 662                 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
 663                 return -EINVAL;
 664         }
 665
 666         /* Keep the compiler happy */
 667         return 0;
 668 }
 669
 670 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 671 {
 672         long ret;
 673
 674         mutex_lock(&pp_do_mutex);
 675         ret = pp_do_ioctl(file, cmd, arg);
 676         mutex_unlock(&pp_do_mutex);
 677         return ret;
 678 }
 679
 680 #ifdef CONFIG_COMPAT
 681 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
 682                             unsigned long arg)
 683 {
 684         return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 685 }
 686 #endif
 687
 688 static int pp_open(struct inode *inode, struct file *file)
 689 {
 690         unsigned int minor = iminor(inode);
 691         struct pp_struct *pp;
 692
 693         if (minor >= PARPORT_MAX)
 694                 return -ENXIO;
 695
 696         pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
 697         if (!pp)
 698                 return -ENOMEM;
 699
 700         pp->state.mode = IEEE1284_MODE_COMPAT;
 701         pp->state.phase = init_phase(pp->state.mode);
 702         pp->flags = 0;
 703         pp->irqresponse = 0;
 704         atomic_set(&pp->irqc, 0);
 705         init_waitqueue_head(&pp->irq_wait);
 706
 707         /* Defer the actual device registration until the first claim.
 708          * That way, we know whether or not the driver wants to have
 709          * exclusive access to the port (PPEXCL).
 710          */
 711         pp->pdev = NULL;
 712         file->private_data = pp;
 713
 714         return 0;
 715 }
 716
 717 static int pp_release(struct inode *inode, struct file *file)
 718 {
 719         unsigned int minor = iminor(inode);
 720         struct pp_struct *pp = file->private_data;
 721         int compat_negot;
 722
 723         compat_negot = 0;
 724         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 725             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 726                 struct ieee1284_info *info;
 727
 728                 /* parport released, but not in compatibility mode */
 729                 parport_claim_or_block(pp->pdev);
 730                 pp->flags |= PP_CLAIMED;
 731                 info = &pp->pdev->port->ieee1284;
 732                 pp->saved_state.mode = info->mode;
 733                 pp->saved_state.phase = info->phase;
 734                 info->mode = pp->state.mode;
 735                 info->phase = pp->state.phase;
 736                 compat_negot = 1;
 737         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 738             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 739                 compat_negot = 2;
 740         }
 741         if (compat_negot) {
 742                 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
 743                 dev_dbg(&pp->pdev->dev,
 744                         "negotiated back to compatibility mode because user-space forgot\n");
 745         }
 746
 747         if (pp->flags & PP_CLAIMED) {
 748                 struct ieee1284_info *info;
 749
 750                 info = &pp->pdev->port->ieee1284;
 751                 pp->state.mode = info->mode;
 752                 pp->state.phase = info->phase;
 753                 info->mode = pp->saved_state.mode;
 754                 info->phase = pp->saved_state.phase;
 755                 parport_release(pp->pdev);
 756                 if (compat_negot != 1) {
 757                         pr_debug(CHRDEV "%x: released pardevice "
 758                                 "because user-space forgot\n", minor);
 759                 }
 760         }
 761
 762         if (pp->pdev) {
 763                 parport_unregister_device(pp->pdev);
 764                 ida_simple_remove(&ida_index, pp->index);
 765                 pp->pdev = NULL;
 766                 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 767         }
 768
 769         kfree(pp);
 770
 771         return 0;
 772 }
 773
 774 /* No kernel lock held - fine */
 775 static unsigned int pp_poll(struct file *file, poll_table *wait)
 776 {
 777         struct pp_struct *pp = file->private_data;
 778         unsigned int mask = 0;
 779
 780         poll_wait(file, &pp->irq_wait, wait);
 781         if (atomic_read(&pp->irqc))
 782                 mask |= POLLIN | POLLRDNORM;
 783
 784         return mask;
 785 }
 786
 787 static struct class *ppdev_class;
 788
 789 static const struct file_operations pp_fops = {
 790         .owner          = THIS_MODULE,
 791         .llseek         = no_llseek,
 792         .read           = pp_read,
 793         .write          = pp_write,
 794         .poll           = pp_poll,
 795         .unlocked_ioctl = pp_ioctl,
 796 #ifdef CONFIG_COMPAT
 797         .compat_ioctl   = pp_compat_ioctl,
 798 #endif
 799         .open           = pp_open,
 800         .release        = pp_release,
 801 };
 802
 803 static void pp_attach(struct parport *port)
 804 {
 805         struct device *ret;
 806
 807         if (devices[port->number])
 808                 return;
 809
 810         ret = device_create(ppdev_class, port->dev,
 811                             MKDEV(PP_MAJOR, port->number), NULL,
 812                             "parport%d", port->number);
 813         if (IS_ERR(ret)) {
 814                 pr_err("Failed to create device parport%d\n",
 815                        port->number);
 816                 return;
 817         }
 818         devices[port->number] = ret;
 819 }
 820
 821 static void pp_detach(struct parport *port)
 822 {
 823         if (!devices[port->number])
 824                 return;
 825
 826         device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 827         devices[port->number] = NULL;
 828 }
 829
 830 static int pp_probe(struct pardevice *par_dev)
 831 {
 832         struct device_driver *drv = par_dev->dev.driver;
 833         int len = strlen(drv->name);
 834
 835         if (strncmp(par_dev->name, drv->name, len))
 836                 return -ENODEV;
 837
 838         return 0;
 839 }
 840
 841 static struct parport_driver pp_driver = {
 842         .name           = CHRDEV,
 843         .probe          = pp_probe,
 844         .match_port     = pp_attach,
 845         .detach         = pp_detach,
 846         .devmodel       = true,
 847 };
 848
 849 static int __init ppdev_init(void)
 850 {
 851         int err = 0;
 852
 853         if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
 854                 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
 855                 return -EIO;
 856         }
 857         ppdev_class = class_create(THIS_MODULE, CHRDEV);
 858         if (IS_ERR(ppdev_class)) {
 859                 err = PTR_ERR(ppdev_class);
 860                 goto out_chrdev;
 861         }
 862         err = parport_register_driver(&pp_driver);
 863         if (err < 0) {
 864                 pr_warn(CHRDEV ": unable to register with parport\n");
 865                 goto out_class;
 866         }
 867
 868         pr_info(PP_VERSION "\n");
 869         goto out;
 870
 871 out_class:
 872         class_destroy(ppdev_class);
 873 out_chrdev:
 874         unregister_chrdev(PP_MAJOR, CHRDEV);
 875 out:
 876         return err;
 877 }
 878
 879 static void __exit ppdev_cleanup(void)
 880 {
 881         /* Clean up all parport stuff */
 882         parport_unregister_driver(&pp_driver);
 883         class_destroy(ppdev_class);
 884         unregister_chrdev(PP_MAJOR, CHRDEV);
 885 }
 886
 887 module_init(ppdev_init);
 888 module_exit(ppdev_cleanup);
 889
 890 MODULE_LICENSE("GPL");
 891 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);