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