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 };
  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         int rc = 0;
 294
 295         name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
 296         if (name == NULL)
 297                 return -ENOMEM;
 298
 299         port = parport_find_number(minor);
 300         if (!port) {
 301                 pr_warn("%s: no associated port!\n", name);
 302                 rc = -ENXIO;
 303                 goto err;
 304         }
 305
 306         memset(&ppdev_cb, 0, sizeof(ppdev_cb));
 307         ppdev_cb.irq_func = pp_irq;
 308         ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 309         ppdev_cb.private = pp;
 310         pdev = parport_register_dev_model(port, name, &ppdev_cb, minor);
 311         parport_put_port(port);
 312
 313         if (!pdev) {
 314                 pr_warn("%s: failed to register device!\n", name);
 315                 rc = -ENXIO;
 316                 goto err;
 317         }
 318
 319         pp->pdev = pdev;
 320         dev_dbg(&pdev->dev, "registered pardevice\n");
 321 err:
 322         kfree(name);
 323         return rc;
 324 }
 325
 326 static enum ieee1284_phase init_phase(int mode)
 327 {
 328         switch (mode & ~(IEEE1284_DEVICEID
 329                          | IEEE1284_ADDR)) {
 330         case IEEE1284_MODE_NIBBLE:
 331         case IEEE1284_MODE_BYTE:
 332                 return IEEE1284_PH_REV_IDLE;
 333         }
 334         return IEEE1284_PH_FWD_IDLE;
 335 }
 336
 337 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
 338 {
 339         long to_jiffies;
 340
 341         if ((tv_sec < 0) || (tv_usec < 0))
 342                 return -EINVAL;
 343
 344         to_jiffies = usecs_to_jiffies(tv_usec);
 345         to_jiffies += tv_sec * HZ;
 346         if (to_jiffies <= 0)
 347                 return -EINVAL;
 348
 349         pdev->timeout = to_jiffies;
 350         return 0;
 351 }
 352
 353 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 354 {
 355         unsigned int minor = iminor(file_inode(file));
 356         struct pp_struct *pp = file->private_data;
 357         struct parport *port;
 358         void __user *argp = (void __user *)arg;
 359
 360         /* First handle the cases that don't take arguments. */
 361         switch (cmd) {
 362         case PPCLAIM:
 363             {
 364                 struct ieee1284_info *info;
 365                 int ret;
 366
 367                 if (pp->flags & PP_CLAIMED) {
 368                         dev_dbg(&pp->pdev->dev, "you've already got it!\n");
 369                         return -EINVAL;
 370                 }
 371
 372                 /* Deferred device registration. */
 373                 if (!pp->pdev) {
 374                         int err = register_device(minor, pp);
 375
 376                         if (err)
 377                                 return err;
 378                 }
 379
 380                 ret = parport_claim_or_block(pp->pdev);
 381                 if (ret < 0)
 382                         return ret;
 383
 384                 pp->flags |= PP_CLAIMED;
 385
 386                 /* For interrupt-reporting to work, we need to be
 387                  * informed of each interrupt. */
 388                 pp_enable_irq(pp);
 389
 390                 /* We may need to fix up the state machine. */
 391                 info = &pp->pdev->port->ieee1284;
 392                 pp->saved_state.mode = info->mode;
 393                 pp->saved_state.phase = info->phase;
 394                 info->mode = pp->state.mode;
 395                 info->phase = pp->state.phase;
 396                 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
 397                 parport_set_timeout(pp->pdev, pp->default_inactivity);
 398
 399                 return 0;
 400             }
 401         case PPEXCL:
 402                 if (pp->pdev) {
 403                         dev_dbg(&pp->pdev->dev,
 404                                 "too late for PPEXCL; already registered\n");
 405                         if (pp->flags & PP_EXCL)
 406                                 /* But it's not really an error. */
 407                                 return 0;
 408                         /* There's no chance of making the driver happy. */
 409                         return -EINVAL;
 410                 }
 411
 412                 /* Just remember to register the device exclusively
 413                  * when we finally do the registration. */
 414                 pp->flags |= PP_EXCL;
 415                 return 0;
 416         case PPSETMODE:
 417             {
 418                 int mode;
 419
 420                 if (copy_from_user(&mode, argp, sizeof(mode)))
 421                         return -EFAULT;
 422                 /* FIXME: validate mode */
 423                 pp->state.mode = mode;
 424                 pp->state.phase = init_phase(mode);
 425
 426                 if (pp->flags & PP_CLAIMED) {
 427                         pp->pdev->port->ieee1284.mode = mode;
 428                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 429                 }
 430
 431                 return 0;
 432             }
 433         case PPGETMODE:
 434             {
 435                 int mode;
 436
 437                 if (pp->flags & PP_CLAIMED)
 438                         mode = pp->pdev->port->ieee1284.mode;
 439                 else
 440                         mode = pp->state.mode;
 441
 442                 if (copy_to_user(argp, &mode, sizeof(mode)))
 443                         return -EFAULT;
 444                 return 0;
 445             }
 446         case PPSETPHASE:
 447             {
 448                 int phase;
 449
 450                 if (copy_from_user(&phase, argp, sizeof(phase)))
 451                         return -EFAULT;
 452
 453                 /* FIXME: validate phase */
 454                 pp->state.phase = phase;
 455
 456                 if (pp->flags & PP_CLAIMED)
 457                         pp->pdev->port->ieee1284.phase = phase;
 458
 459                 return 0;
 460             }
 461         case PPGETPHASE:
 462             {
 463                 int phase;
 464
 465                 if (pp->flags & PP_CLAIMED)
 466                         phase = pp->pdev->port->ieee1284.phase;
 467                 else
 468                         phase = pp->state.phase;
 469                 if (copy_to_user(argp, &phase, sizeof(phase)))
 470                         return -EFAULT;
 471                 return 0;
 472             }
 473         case PPGETMODES:
 474             {
 475                 unsigned int modes;
 476
 477                 port = parport_find_number(minor);
 478                 if (!port)
 479                         return -ENODEV;
 480
 481                 modes = port->modes;
 482                 parport_put_port(port);
 483                 if (copy_to_user(argp, &modes, sizeof(modes)))
 484                         return -EFAULT;
 485                 return 0;
 486             }
 487         case PPSETFLAGS:
 488             {
 489                 int uflags;
 490
 491                 if (copy_from_user(&uflags, argp, sizeof(uflags)))
 492                         return -EFAULT;
 493                 pp->flags &= ~PP_FLAGMASK;
 494                 pp->flags |= (uflags & PP_FLAGMASK);
 495                 return 0;
 496             }
 497         case PPGETFLAGS:
 498             {
 499                 int uflags;
 500
 501                 uflags = pp->flags & PP_FLAGMASK;
 502                 if (copy_to_user(argp, &uflags, sizeof(uflags)))
 503                         return -EFAULT;
 504                 return 0;
 505             }
 506         }       /* end switch() */
 507
 508         /* Everything else requires the port to be claimed, so check
 509          * that now. */
 510         if ((pp->flags & PP_CLAIMED) == 0) {
 511                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 512                 return -EINVAL;
 513         }
 514
 515         port = pp->pdev->port;
 516         switch (cmd) {
 517                 struct ieee1284_info *info;
 518                 unsigned char reg;
 519                 unsigned char mask;
 520                 int mode;
 521                 s32 time32[2];
 522                 s64 time64[2];
 523                 struct timespec64 ts;
 524                 int ret;
 525
 526         case PPRSTATUS:
 527                 reg = parport_read_status(port);
 528                 if (copy_to_user(argp, &reg, sizeof(reg)))
 529                         return -EFAULT;
 530                 return 0;
 531         case PPRDATA:
 532                 reg = parport_read_data(port);
 533                 if (copy_to_user(argp, &reg, sizeof(reg)))
 534                         return -EFAULT;
 535                 return 0;
 536         case PPRCONTROL:
 537                 reg = parport_read_control(port);
 538                 if (copy_to_user(argp, &reg, sizeof(reg)))
 539                         return -EFAULT;
 540                 return 0;
 541         case PPYIELD:
 542                 parport_yield_blocking(pp->pdev);
 543                 return 0;
 544
 545         case PPRELEASE:
 546                 /* Save the state machine's state. */
 547                 info = &pp->pdev->port->ieee1284;
 548                 pp->state.mode = info->mode;
 549                 pp->state.phase = info->phase;
 550                 info->mode = pp->saved_state.mode;
 551                 info->phase = pp->saved_state.phase;
 552                 parport_release(pp->pdev);
 553                 pp->flags &= ~PP_CLAIMED;
 554                 return 0;
 555
 556         case PPWCONTROL:
 557                 if (copy_from_user(&reg, argp, sizeof(reg)))
 558                         return -EFAULT;
 559                 parport_write_control(port, reg);
 560                 return 0;
 561
 562         case PPWDATA:
 563                 if (copy_from_user(&reg, argp, sizeof(reg)))
 564                         return -EFAULT;
 565                 parport_write_data(port, reg);
 566                 return 0;
 567
 568         case PPFCONTROL:
 569                 if (copy_from_user(&mask, argp,
 570                                    sizeof(mask)))
 571                         return -EFAULT;
 572                 if (copy_from_user(&reg, 1 + (unsigned char __user *) arg,
 573                                    sizeof(reg)))
 574                         return -EFAULT;
 575                 parport_frob_control(port, mask, reg);
 576                 return 0;
 577
 578         case PPDATADIR:
 579                 if (copy_from_user(&mode, argp, sizeof(mode)))
 580                         return -EFAULT;
 581                 if (mode)
 582                         port->ops->data_reverse(port);
 583                 else
 584                         port->ops->data_forward(port);
 585                 return 0;
 586
 587         case PPNEGOT:
 588                 if (copy_from_user(&mode, argp, sizeof(mode)))
 589                         return -EFAULT;
 590                 switch ((ret = parport_negotiate(port, mode))) {
 591                 case 0: break;
 592                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 593                         ret = -EIO;
 594                         break;
 595                 case 1:  /* handshake succeeded, peripheral rejected mode */
 596                         ret = -ENXIO;
 597                         break;
 598                 }
 599                 pp_enable_irq(pp);
 600                 return ret;
 601
 602         case PPWCTLONIRQ:
 603                 if (copy_from_user(&reg, argp, sizeof(reg)))
 604                         return -EFAULT;
 605
 606                 /* Remember what to set the control lines to, for next
 607                  * time we get an interrupt. */
 608                 pp->irqctl = reg;
 609                 pp->irqresponse = 1;
 610                 return 0;
 611
 612         case PPCLRIRQ:
 613                 ret = atomic_read(&pp->irqc);
 614                 if (copy_to_user(argp, &ret, sizeof(ret)))
 615                         return -EFAULT;
 616                 atomic_sub(ret, &pp->irqc);
 617                 return 0;
 618
 619         case PPSETTIME32:
 620                 if (copy_from_user(time32, argp, sizeof(time32)))
 621                         return -EFAULT;
 622
 623                 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
 624
 625         case PPSETTIME64:
 626                 if (copy_from_user(time64, argp, sizeof(time64)))
 627                         return -EFAULT;
 628
 629                 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
 630
 631         case PPGETTIME32:
 632                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 633                 time32[0] = ts.tv_sec;
 634                 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
 635                 if ((time32[0] < 0) || (time32[1] < 0))
 636                         return -EINVAL;
 637
 638                 if (copy_to_user(argp, time32, sizeof(time32)))
 639                         return -EFAULT;
 640
 641                 return 0;
 642
 643         case PPGETTIME64:
 644                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 645                 time64[0] = ts.tv_sec;
 646                 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
 647                 if ((time64[0] < 0) || (time64[1] < 0))
 648                         return -EINVAL;
 649
 650                 if (copy_to_user(argp, time64, sizeof(time64)))
 651                         return -EFAULT;
 652
 653                 return 0;
 654
 655         default:
 656                 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
 657                 return -EINVAL;
 658         }
 659
 660         /* Keep the compiler happy */
 661         return 0;
 662 }
 663
 664 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 665 {
 666         long ret;
 667
 668         mutex_lock(&pp_do_mutex);
 669         ret = pp_do_ioctl(file, cmd, arg);
 670         mutex_unlock(&pp_do_mutex);
 671         return ret;
 672 }
 673
 674 #ifdef CONFIG_COMPAT
 675 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
 676                             unsigned long arg)
 677 {
 678         return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 679 }
 680 #endif
 681
 682 static int pp_open(struct inode *inode, struct file *file)
 683 {
 684         unsigned int minor = iminor(inode);
 685         struct pp_struct *pp;
 686
 687         if (minor >= PARPORT_MAX)
 688                 return -ENXIO;
 689
 690         pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
 691         if (!pp)
 692                 return -ENOMEM;
 693
 694         pp->state.mode = IEEE1284_MODE_COMPAT;
 695         pp->state.phase = init_phase(pp->state.mode);
 696         pp->flags = 0;
 697         pp->irqresponse = 0;
 698         atomic_set(&pp->irqc, 0);
 699         init_waitqueue_head(&pp->irq_wait);
 700
 701         /* Defer the actual device registration until the first claim.
 702          * That way, we know whether or not the driver wants to have
 703          * exclusive access to the port (PPEXCL).
 704          */
 705         pp->pdev = NULL;
 706         file->private_data = pp;
 707
 708         return 0;
 709 }
 710
 711 static int pp_release(struct inode *inode, struct file *file)
 712 {
 713         unsigned int minor = iminor(inode);
 714         struct pp_struct *pp = file->private_data;
 715         int compat_negot;
 716
 717         compat_negot = 0;
 718         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 719             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 720                 struct ieee1284_info *info;
 721
 722                 /* parport released, but not in compatibility mode */
 723                 parport_claim_or_block(pp->pdev);
 724                 pp->flags |= PP_CLAIMED;
 725                 info = &pp->pdev->port->ieee1284;
 726                 pp->saved_state.mode = info->mode;
 727                 pp->saved_state.phase = info->phase;
 728                 info->mode = pp->state.mode;
 729                 info->phase = pp->state.phase;
 730                 compat_negot = 1;
 731         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 732             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 733                 compat_negot = 2;
 734         }
 735         if (compat_negot) {
 736                 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
 737                 dev_dbg(&pp->pdev->dev,
 738                         "negotiated back to compatibility mode because user-space forgot\n");
 739         }
 740
 741         if (pp->flags & PP_CLAIMED) {
 742                 struct ieee1284_info *info;
 743
 744                 info = &pp->pdev->port->ieee1284;
 745                 pp->state.mode = info->mode;
 746                 pp->state.phase = info->phase;
 747                 info->mode = pp->saved_state.mode;
 748                 info->phase = pp->saved_state.phase;
 749                 parport_release(pp->pdev);
 750                 if (compat_negot != 1) {
 751                         pr_debug(CHRDEV "%x: released pardevice "
 752                                 "because user-space forgot\n", minor);
 753                 }
 754         }
 755
 756         if (pp->pdev) {
 757                 parport_unregister_device(pp->pdev);
 758                 pp->pdev = NULL;
 759                 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 760         }
 761
 762         kfree(pp);
 763
 764         return 0;
 765 }
 766
 767 /* No kernel lock held - fine */
 768 static unsigned int pp_poll(struct file *file, poll_table *wait)
 769 {
 770         struct pp_struct *pp = file->private_data;
 771         unsigned int mask = 0;
 772
 773         poll_wait(file, &pp->irq_wait, wait);
 774         if (atomic_read(&pp->irqc))
 775                 mask |= POLLIN | POLLRDNORM;
 776
 777         return mask;
 778 }
 779
 780 static struct class *ppdev_class;
 781
 782 static const struct file_operations pp_fops = {
 783         .owner          = THIS_MODULE,
 784         .llseek         = no_llseek,
 785         .read           = pp_read,
 786         .write          = pp_write,
 787         .poll           = pp_poll,
 788         .unlocked_ioctl = pp_ioctl,
 789 #ifdef CONFIG_COMPAT
 790         .compat_ioctl   = pp_compat_ioctl,
 791 #endif
 792         .open           = pp_open,
 793         .release        = pp_release,
 794 };
 795
 796 static void pp_attach(struct parport *port)
 797 {
 798         struct device *ret;
 799
 800         if (devices[port->number])
 801                 return;
 802
 803         ret = device_create(ppdev_class, port->dev,
 804                             MKDEV(PP_MAJOR, port->number), NULL,
 805                             "parport%d", port->number);
 806         if (IS_ERR(ret)) {
 807                 pr_err("Failed to create device parport%d\n",
 808                        port->number);
 809                 return;
 810         }
 811         devices[port->number] = ret;
 812 }
 813
 814 static void pp_detach(struct parport *port)
 815 {
 816         if (!devices[port->number])
 817                 return;
 818
 819         device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 820         devices[port->number] = NULL;
 821 }
 822
 823 static int pp_probe(struct pardevice *par_dev)
 824 {
 825         struct device_driver *drv = par_dev->dev.driver;
 826         int len = strlen(drv->name);
 827
 828         if (strncmp(par_dev->name, drv->name, len))
 829                 return -ENODEV;
 830
 831         return 0;
 832 }
 833
 834 static struct parport_driver pp_driver = {
 835         .name           = CHRDEV,
 836         .probe          = pp_probe,
 837         .match_port     = pp_attach,
 838         .detach         = pp_detach,
 839         .devmodel       = true,
 840 };
 841
 842 static int __init ppdev_init(void)
 843 {
 844         int err = 0;
 845
 846         if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
 847                 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
 848                 return -EIO;
 849         }
 850         ppdev_class = class_create(THIS_MODULE, CHRDEV);
 851         if (IS_ERR(ppdev_class)) {
 852                 err = PTR_ERR(ppdev_class);
 853                 goto out_chrdev;
 854         }
 855         err = parport_register_driver(&pp_driver);
 856         if (err < 0) {
 857                 pr_warn(CHRDEV ": unable to register with parport\n");
 858                 goto out_class;
 859         }
 860
 861         pr_info(PP_VERSION "\n");
 862         goto out;
 863
 864 out_class:
 865         class_destroy(ppdev_class);
 866 out_chrdev:
 867         unregister_chrdev(PP_MAJOR, CHRDEV);
 868 out:
 869         return err;
 870 }
 871
 872 static void __exit ppdev_cleanup(void)
 873 {
 874         /* Clean up all parport stuff */
 875         parport_unregister_driver(&pp_driver);
 876         class_destroy(ppdev_class);
 877         unregister_chrdev(PP_MAJOR, CHRDEV);
 878 }
 879
 880 module_init(ppdev_init);
 881 module_exit(ppdev_cleanup);
 882
 883 MODULE_LICENSE("GPL");
 884 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);