drivers/char/ppdev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * linux/drivers/char/ppdev.c
   4  *
   5  * This is the code behind /dev/parport* -- it allows a user-space
   6  * application to use the parport subsystem.
   7  *
   8  * Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
   9  *
  10  * A /dev/parportx device node represents an arbitrary device
  11  * on port 'x'.  The following operations are possible:
  12  *
  13  * open         do nothing, set up default IEEE 1284 protocol to be COMPAT
  14  * close        release port and unregister device (if necessary)
  15  * ioctl
  16  *   EXCL       register device exclusively (may fail)
  17  *   CLAIM      (register device first time) parport_claim_or_block
  18  *   RELEASE    parport_release
  19  *   SETMODE    set the IEEE 1284 protocol to use for read/write
  20  *   SETPHASE   set the IEEE 1284 phase of a particular mode.  Not to be
  21  *              confused with ioctl(fd, SETPHASER, &stun). ;-)
  22  *   DATADIR    data_forward / data_reverse
  23  *   WDATA      write_data
  24  *   RDATA      read_data
  25  *   WCONTROL   write_control
  26  *   RCONTROL   read_control
  27  *   FCONTROL   frob_control
  28  *   RSTATUS    read_status
  29  *   NEGOT      parport_negotiate
  30  *   YIELD      parport_yield_blocking
  31  *   WCTLONIRQ  on interrupt, set control lines
  32  *   CLRIRQ     clear (and return) interrupt count
  33  *   SETTIME    sets device timeout (struct timeval)
  34  *   GETTIME    gets device timeout (struct timeval)
  35  *   GETMODES   gets hardware supported modes (unsigned int)
  36  *   GETMODE    gets the current IEEE1284 mode
  37  *   GETPHASE   gets the current IEEE1284 phase
  38  *   GETFLAGS   gets current (user-visible) flags
  39  *   SETFLAGS   sets current (user-visible) flags
  40  * read/write   read or write in current IEEE 1284 protocol
  41  * select       wait for interrupt (in readfds)
  42  *
  43  * Changes:
  44  * Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
  45  *
  46  * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
  47  * - On error, copy_from_user and copy_to_user do not return -EFAULT,
  48  *   They return the positive number of bytes *not* copied due to address
  49  *   space errors.
  50  *
  51  * Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
  52  * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
  53  */
  54
  55 #include <linux/module.h>
  56 #include <linux/init.h>
  57 #include <linux/sched/signal.h>
  58 #include <linux/device.h>
  59 #include <linux/ioctl.h>
  60 #include <linux/parport.h>
  61 #include <linux/ctype.h>
  62 #include <linux/poll.h>
  63 #include <linux/slab.h>
  64 #include <linux/major.h>
  65 #include <linux/ppdev.h>
  66 #include <linux/mutex.h>
  67 #include <linux/uaccess.h>
  68 #include <linux/compat.h>
  69
  70 #define PP_VERSION "ppdev: user-space parallel port driver"
  71 #define CHRDEV "ppdev"
  72
  73 struct pp_struct {
  74         struct pardevice *pdev;
  75         wait_queue_head_t irq_wait;
  76         atomic_t irqc;
  77         unsigned int flags;
  78         int irqresponse;
  79         unsigned char irqctl;
  80         struct ieee1284_info state;
  81         struct ieee1284_info saved_state;
  82         long default_inactivity;
  83         int index;
  84 };
  85
  86 /* should we use PARDEVICE_MAX here? */
  87 static struct device *devices[PARPORT_MAX];
  88
  89 static DEFINE_IDA(ida_index);
  90
  91 /* pp_struct.flags bitfields */
  92 #define PP_CLAIMED    (1<<0)
  93 #define PP_EXCL       (1<<1)
  94
  95 /* Other constants */
  96 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
  97 #define PP_BUFFER_SIZE 1024
  98 #define PARDEVICE_MAX 8
  99
 100 static DEFINE_MUTEX(pp_do_mutex);
 101
 102 /* define fixed sized ioctl cmd for y2038 migration */
 103 #define PPGETTIME32     _IOR(PP_IOCTL, 0x95, s32[2])
 104 #define PPSETTIME32     _IOW(PP_IOCTL, 0x96, s32[2])
 105 #define PPGETTIME64     _IOR(PP_IOCTL, 0x95, s64[2])
 106 #define PPSETTIME64     _IOW(PP_IOCTL, 0x96, s64[2])
 107
 108 static inline void pp_enable_irq(struct pp_struct *pp)
 109 {
 110         struct parport *port = pp->pdev->port;
 111
 112         port->ops->enable_irq(port);
 113 }
 114
 115 static ssize_t pp_read(struct file *file, char __user *buf, size_t count,
 116                        loff_t *ppos)
 117 {
 118         unsigned int minor = iminor(file_inode(file));
 119         struct pp_struct *pp = file->private_data;
 120         char *kbuffer;
 121         ssize_t bytes_read = 0;
 122         struct parport *pport;
 123         int mode;
 124
 125         if (!(pp->flags & PP_CLAIMED)) {
 126                 /* Don't have the port claimed */
 127                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 128                 return -EINVAL;
 129         }
 130
 131         /* Trivial case. */
 132         if (count == 0)
 133                 return 0;
 134
 135         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 136         if (!kbuffer)
 137                 return -ENOMEM;
 138         pport = pp->pdev->port;
 139         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 140
 141         parport_set_timeout(pp->pdev,
 142                             (file->f_flags & O_NONBLOCK) ?
 143                             PARPORT_INACTIVITY_O_NONBLOCK :
 144                             pp->default_inactivity);
 145
 146         while (bytes_read == 0) {
 147                 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
 148
 149                 if (mode == IEEE1284_MODE_EPP) {
 150                         /* various specials for EPP mode */
 151                         int flags = 0;
 152                         size_t (*fn)(struct parport *, void *, size_t, int);
 153
 154                         if (pp->flags & PP_W91284PIC)
 155                                 flags |= PARPORT_W91284PIC;
 156                         if (pp->flags & PP_FASTREAD)
 157                                 flags |= PARPORT_EPP_FAST;
 158                         if (pport->ieee1284.mode & IEEE1284_ADDR)
 159                                 fn = pport->ops->epp_read_addr;
 160                         else
 161                                 fn = pport->ops->epp_read_data;
 162                         bytes_read = (*fn)(pport, kbuffer, need, flags);
 163                 } else {
 164                         bytes_read = parport_read(pport, kbuffer, need);
 165                 }
 166
 167                 if (bytes_read != 0)
 168                         break;
 169
 170                 if (file->f_flags & O_NONBLOCK) {
 171                         bytes_read = -EAGAIN;
 172                         break;
 173                 }
 174
 175                 if (signal_pending(current)) {
 176                         bytes_read = -ERESTARTSYS;
 177                         break;
 178                 }
 179
 180                 cond_resched();
 181         }
 182
 183         parport_set_timeout(pp->pdev, pp->default_inactivity);
 184
 185         if (bytes_read > 0 && copy_to_user(buf, kbuffer, bytes_read))
 186                 bytes_read = -EFAULT;
 187
 188         kfree(kbuffer);
 189         pp_enable_irq(pp);
 190         return bytes_read;
 191 }
 192
 193 static ssize_t pp_write(struct file *file, const char __user *buf,
 194                         size_t count, loff_t *ppos)
 195 {
 196         unsigned int minor = iminor(file_inode(file));
 197         struct pp_struct *pp = file->private_data;
 198         char *kbuffer;
 199         ssize_t bytes_written = 0;
 200         ssize_t wrote;
 201         int mode;
 202         struct parport *pport;
 203
 204         if (!(pp->flags & PP_CLAIMED)) {
 205                 /* Don't have the port claimed */
 206                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 207                 return -EINVAL;
 208         }
 209
 210         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 211         if (!kbuffer)
 212                 return -ENOMEM;
 213
 214         pport = pp->pdev->port;
 215         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 216
 217         parport_set_timeout(pp->pdev,
 218                             (file->f_flags & O_NONBLOCK) ?
 219                             PARPORT_INACTIVITY_O_NONBLOCK :
 220                             pp->default_inactivity);
 221
 222         while (bytes_written < count) {
 223                 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
 224
 225                 if (copy_from_user(kbuffer, buf + bytes_written, n)) {
 226                         bytes_written = -EFAULT;
 227                         break;
 228                 }
 229
 230                 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
 231                         /* do a fast EPP write */
 232                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 233                                 wrote = pport->ops->epp_write_addr(pport,
 234                                         kbuffer, n, PARPORT_EPP_FAST);
 235                         } else {
 236                                 wrote = pport->ops->epp_write_data(pport,
 237                                         kbuffer, n, PARPORT_EPP_FAST);
 238                         }
 239                 } else {
 240                         wrote = parport_write(pp->pdev->port, kbuffer, n);
 241                 }
 242
 243                 if (wrote <= 0) {
 244                         if (!bytes_written)
 245                                 bytes_written = wrote;
 246                         break;
 247                 }
 248
 249                 bytes_written += wrote;
 250
 251                 if (file->f_flags & O_NONBLOCK) {
 252                         if (!bytes_written)
 253                                 bytes_written = -EAGAIN;
 254                         break;
 255                 }
 256
 257                 if (signal_pending(current))
 258                         break;
 259
 260                 cond_resched();
 261         }
 262
 263         parport_set_timeout(pp->pdev, pp->default_inactivity);
 264
 265         kfree(kbuffer);
 266         pp_enable_irq(pp);
 267         return bytes_written;
 268 }
 269
 270 static void pp_irq(void *private)
 271 {
 272         struct pp_struct *pp = private;
 273
 274         if (pp->irqresponse) {
 275                 parport_write_control(pp->pdev->port, pp->irqctl);
 276                 pp->irqresponse = 0;
 277         }
 278
 279         atomic_inc(&pp->irqc);
 280         wake_up_interruptible(&pp->irq_wait);
 281 }
 282
 283 static int register_device(int minor, struct pp_struct *pp)
 284 {
 285         struct parport *port;
 286         struct pardevice *pdev = NULL;
 287         char *name;
 288         struct pardev_cb ppdev_cb;
 289         int rc = 0, index;
 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                 pr_warn("%s: no associated port!\n", name);
 298                 rc = -ENXIO;
 299                 goto err;
 300         }
 301
 302         index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
 303         memset(&ppdev_cb, 0, sizeof(ppdev_cb));
 304         ppdev_cb.irq_func = pp_irq;
 305         ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 306         ppdev_cb.private = pp;
 307         pdev = parport_register_dev_model(port, name, &ppdev_cb, index);
 308         parport_put_port(port);
 309
 310         if (!pdev) {
 311                 pr_warn("%s: failed to register device!\n", name);
 312                 rc = -ENXIO;
 313                 ida_simple_remove(&ida_index, index);
 314                 goto err;
 315         }
 316
 317         pp->pdev = pdev;
 318         pp->index = index;
 319         dev_dbg(&pdev->dev, "registered pardevice\n");
 320 err:
 321         kfree(name);
 322         return rc;
 323 }
 324
 325 static enum ieee1284_phase init_phase(int mode)
 326 {
 327         switch (mode & ~(IEEE1284_DEVICEID
 328                          | IEEE1284_ADDR)) {
 329         case IEEE1284_MODE_NIBBLE:
 330         case IEEE1284_MODE_BYTE:
 331                 return IEEE1284_PH_REV_IDLE;
 332         }
 333         return IEEE1284_PH_FWD_IDLE;
 334 }
 335
 336 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
 337 {
 338         long to_jiffies;
 339
 340         if ((tv_sec < 0) || (tv_usec < 0))
 341                 return -EINVAL;
 342
 343         to_jiffies = usecs_to_jiffies(tv_usec);
 344         to_jiffies += tv_sec * HZ;
 345         if (to_jiffies <= 0)
 346                 return -EINVAL;
 347
 348         pdev->timeout = to_jiffies;
 349         return 0;
 350 }
 351
 352 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 353 {
 354         unsigned int minor = iminor(file_inode(file));
 355         struct pp_struct *pp = file->private_data;
 356         struct parport *port;
 357         void __user *argp = (void __user *)arg;
 358         struct ieee1284_info *info;
 359         unsigned char reg;
 360         unsigned char mask;
 361         int mode;
 362         s32 time32[2];
 363         s64 time64[2];
 364         struct timespec64 ts;
 365         int ret;
 366
 367         /* First handle the cases that don't take arguments. */
 368         switch (cmd) {
 369         case PPCLAIM:
 370             {
 371                 if (pp->flags & PP_CLAIMED) {
 372                         dev_dbg(&pp->pdev->dev, "you've already got it!\n");
 373                         return -EINVAL;
 374                 }
 375
 376                 /* Deferred device registration. */
 377                 if (!pp->pdev) {
 378                         int err = register_device(minor, pp);
 379
 380                         if (err)
 381                                 return err;
 382                 }
 383
 384                 ret = parport_claim_or_block(pp->pdev);
 385                 if (ret < 0)
 386                         return ret;
 387
 388                 pp->flags |= PP_CLAIMED;
 389
 390                 /* For interrupt-reporting to work, we need to be
 391                  * informed of each interrupt. */
 392                 pp_enable_irq(pp);
 393
 394                 /* We may need to fix up the state machine. */
 395                 info = &pp->pdev->port->ieee1284;
 396                 pp->saved_state.mode = info->mode;
 397                 pp->saved_state.phase = info->phase;
 398                 info->mode = pp->state.mode;
 399                 info->phase = pp->state.phase;
 400                 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
 401                 parport_set_timeout(pp->pdev, pp->default_inactivity);
 402
 403                 return 0;
 404             }
 405         case PPEXCL:
 406                 if (pp->pdev) {
 407                         dev_dbg(&pp->pdev->dev,
 408                                 "too late for PPEXCL; already registered\n");
 409                         if (pp->flags & PP_EXCL)
 410                                 /* But it's not really an error. */
 411                                 return 0;
 412                         /* There's no chance of making the driver happy. */
 413                         return -EINVAL;
 414                 }
 415
 416                 /* Just remember to register the device exclusively
 417                  * when we finally do the registration. */
 418                 pp->flags |= PP_EXCL;
 419                 return 0;
 420         case PPSETMODE:
 421             {
 422                 int mode;
 423
 424                 if (copy_from_user(&mode, argp, sizeof(mode)))
 425                         return -EFAULT;
 426                 /* FIXME: validate mode */
 427                 pp->state.mode = mode;
 428                 pp->state.phase = init_phase(mode);
 429
 430                 if (pp->flags & PP_CLAIMED) {
 431                         pp->pdev->port->ieee1284.mode = mode;
 432                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 433                 }
 434
 435                 return 0;
 436             }
 437         case PPGETMODE:
 438             {
 439                 int mode;
 440
 441                 if (pp->flags & PP_CLAIMED)
 442                         mode = pp->pdev->port->ieee1284.mode;
 443                 else
 444                         mode = pp->state.mode;
 445
 446                 if (copy_to_user(argp, &mode, sizeof(mode)))
 447                         return -EFAULT;
 448                 return 0;
 449             }
 450         case PPSETPHASE:
 451             {
 452                 int phase;
 453
 454                 if (copy_from_user(&phase, argp, sizeof(phase)))
 455                         return -EFAULT;
 456
 457                 /* FIXME: validate phase */
 458                 pp->state.phase = phase;
 459
 460                 if (pp->flags & PP_CLAIMED)
 461                         pp->pdev->port->ieee1284.phase = phase;
 462
 463                 return 0;
 464             }
 465         case PPGETPHASE:
 466             {
 467                 int phase;
 468
 469                 if (pp->flags & PP_CLAIMED)
 470                         phase = pp->pdev->port->ieee1284.phase;
 471                 else
 472                         phase = pp->state.phase;
 473                 if (copy_to_user(argp, &phase, sizeof(phase)))
 474                         return -EFAULT;
 475                 return 0;
 476             }
 477         case PPGETMODES:
 478             {
 479                 unsigned int modes;
 480
 481                 port = parport_find_number(minor);
 482                 if (!port)
 483                         return -ENODEV;
 484
 485                 modes = port->modes;
 486                 parport_put_port(port);
 487                 if (copy_to_user(argp, &modes, sizeof(modes)))
 488                         return -EFAULT;
 489                 return 0;
 490             }
 491         case PPSETFLAGS:
 492             {
 493                 int uflags;
 494
 495                 if (copy_from_user(&uflags, argp, sizeof(uflags)))
 496                         return -EFAULT;
 497                 pp->flags &= ~PP_FLAGMASK;
 498                 pp->flags |= (uflags & PP_FLAGMASK);
 499                 return 0;
 500             }
 501         case PPGETFLAGS:
 502             {
 503                 int uflags;
 504
 505                 uflags = pp->flags & PP_FLAGMASK;
 506                 if (copy_to_user(argp, &uflags, sizeof(uflags)))
 507                         return -EFAULT;
 508                 return 0;
 509             }
 510         }       /* end switch() */
 511
 512         /* Everything else requires the port to be claimed, so check
 513          * that now. */
 514         if ((pp->flags & PP_CLAIMED) == 0) {
 515                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 516                 return -EINVAL;
 517         }
 518
 519         port = pp->pdev->port;
 520         switch (cmd) {
 521         case PPRSTATUS:
 522                 reg = parport_read_status(port);
 523                 if (copy_to_user(argp, &reg, sizeof(reg)))
 524                         return -EFAULT;
 525                 return 0;
 526         case PPRDATA:
 527                 reg = parport_read_data(port);
 528                 if (copy_to_user(argp, &reg, sizeof(reg)))
 529                         return -EFAULT;
 530                 return 0;
 531         case PPRCONTROL:
 532                 reg = parport_read_control(port);
 533                 if (copy_to_user(argp, &reg, sizeof(reg)))
 534                         return -EFAULT;
 535                 return 0;
 536         case PPYIELD:
 537                 parport_yield_blocking(pp->pdev);
 538                 return 0;
 539
 540         case PPRELEASE:
 541                 /* Save the state machine's state. */
 542                 info = &pp->pdev->port->ieee1284;
 543                 pp->state.mode = info->mode;
 544                 pp->state.phase = info->phase;
 545                 info->mode = pp->saved_state.mode;
 546                 info->phase = pp->saved_state.phase;
 547                 parport_release(pp->pdev);
 548                 pp->flags &= ~PP_CLAIMED;
 549                 return 0;
 550
 551         case PPWCONTROL:
 552                 if (copy_from_user(&reg, argp, sizeof(reg)))
 553                         return -EFAULT;
 554                 parport_write_control(port, reg);
 555                 return 0;
 556
 557         case PPWDATA:
 558                 if (copy_from_user(&reg, argp, sizeof(reg)))
 559                         return -EFAULT;
 560                 parport_write_data(port, reg);
 561                 return 0;
 562
 563         case PPFCONTROL:
 564                 if (copy_from_user(&mask, argp,
 565                                    sizeof(mask)))
 566                         return -EFAULT;
 567                 if (copy_from_user(&reg, 1 + (unsigned char __user *) arg,
 568                                    sizeof(reg)))
 569                         return -EFAULT;
 570                 parport_frob_control(port, mask, reg);
 571                 return 0;
 572
 573         case PPDATADIR:
 574                 if (copy_from_user(&mode, argp, sizeof(mode)))
 575                         return -EFAULT;
 576                 if (mode)
 577                         port->ops->data_reverse(port);
 578                 else
 579                         port->ops->data_forward(port);
 580                 return 0;
 581
 582         case PPNEGOT:
 583                 if (copy_from_user(&mode, argp, sizeof(mode)))
 584                         return -EFAULT;
 585                 switch ((ret = parport_negotiate(port, mode))) {
 586                 case 0: break;
 587                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 588                         ret = -EIO;
 589                         break;
 590                 case 1:  /* handshake succeeded, peripheral rejected mode */
 591                         ret = -ENXIO;
 592                         break;
 593                 }
 594                 pp_enable_irq(pp);
 595                 return ret;
 596
 597         case PPWCTLONIRQ:
 598                 if (copy_from_user(&reg, argp, sizeof(reg)))
 599                         return -EFAULT;
 600
 601                 /* Remember what to set the control lines to, for next
 602                  * time we get an interrupt. */
 603                 pp->irqctl = reg;
 604                 pp->irqresponse = 1;
 605                 return 0;
 606
 607         case PPCLRIRQ:
 608                 ret = atomic_read(&pp->irqc);
 609                 if (copy_to_user(argp, &ret, sizeof(ret)))
 610                         return -EFAULT;
 611                 atomic_sub(ret, &pp->irqc);
 612                 return 0;
 613
 614         case PPSETTIME32:
 615                 if (copy_from_user(time32, argp, sizeof(time32)))
 616                         return -EFAULT;
 617
 618                 if ((time32[0] < 0) || (time32[1] < 0))
 619                         return -EINVAL;
 620
 621                 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
 622
 623         case PPSETTIME64:
 624                 if (copy_from_user(time64, argp, sizeof(time64)))
 625                         return -EFAULT;
 626
 627                 if ((time64[0] < 0) || (time64[1] < 0))
 628                         return -EINVAL;
 629
 630                 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
 631                         time64[1] >>= 32;
 632
 633                 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
 634
 635         case PPGETTIME32:
 636                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 637                 time32[0] = ts.tv_sec;
 638                 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
 639
 640                 if (copy_to_user(argp, time32, sizeof(time32)))
 641                         return -EFAULT;
 642
 643                 return 0;
 644
 645         case PPGETTIME64:
 646                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 647                 time64[0] = ts.tv_sec;
 648                 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
 649
 650                 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
 651                         time64[1] <<= 32;
 652
 653                 if (copy_to_user(argp, time64, sizeof(time64)))
 654                         return -EFAULT;
 655
 656                 return 0;
 657
 658         default:
 659                 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
 660                 return -EINVAL;
 661         }
 662
 663         /* Keep the compiler happy */
 664         return 0;
 665 }
 666
 667 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 668 {
 669         long ret;
 670
 671         mutex_lock(&pp_do_mutex);
 672         ret = pp_do_ioctl(file, cmd, arg);
 673         mutex_unlock(&pp_do_mutex);
 674         return ret;
 675 }
 676
 677 static int pp_open(struct inode *inode, struct file *file)
 678 {
 679         unsigned int minor = iminor(inode);
 680         struct pp_struct *pp;
 681
 682         if (minor >= PARPORT_MAX)
 683                 return -ENXIO;
 684
 685         pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
 686         if (!pp)
 687                 return -ENOMEM;
 688
 689         pp->state.mode = IEEE1284_MODE_COMPAT;
 690         pp->state.phase = init_phase(pp->state.mode);
 691         pp->flags = 0;
 692         pp->irqresponse = 0;
 693         atomic_set(&pp->irqc, 0);
 694         init_waitqueue_head(&pp->irq_wait);
 695
 696         /* Defer the actual device registration until the first claim.
 697          * That way, we know whether or not the driver wants to have
 698          * exclusive access to the port (PPEXCL).
 699          */
 700         pp->pdev = NULL;
 701         file->private_data = pp;
 702
 703         return 0;
 704 }
 705
 706 static int pp_release(struct inode *inode, struct file *file)
 707 {
 708         unsigned int minor = iminor(inode);
 709         struct pp_struct *pp = file->private_data;
 710         int compat_negot;
 711
 712         compat_negot = 0;
 713         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 714             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 715                 struct ieee1284_info *info;
 716
 717                 /* parport released, but not in compatibility mode */
 718                 parport_claim_or_block(pp->pdev);
 719                 pp->flags |= PP_CLAIMED;
 720                 info = &pp->pdev->port->ieee1284;
 721                 pp->saved_state.mode = info->mode;
 722                 pp->saved_state.phase = info->phase;
 723                 info->mode = pp->state.mode;
 724                 info->phase = pp->state.phase;
 725                 compat_negot = 1;
 726         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 727             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 728                 compat_negot = 2;
 729         }
 730         if (compat_negot) {
 731                 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
 732                 dev_dbg(&pp->pdev->dev,
 733                         "negotiated back to compatibility mode because user-space forgot\n");
 734         }
 735
 736         if ((pp->flags & PP_CLAIMED) && pp->pdev) {
 737                 struct ieee1284_info *info;
 738
 739                 info = &pp->pdev->port->ieee1284;
 740                 pp->state.mode = info->mode;
 741                 pp->state.phase = info->phase;
 742                 info->mode = pp->saved_state.mode;
 743                 info->phase = pp->saved_state.phase;
 744                 parport_release(pp->pdev);
 745                 if (compat_negot != 1) {
 746                         pr_debug(CHRDEV "%x: released pardevice "
 747                                 "because user-space forgot\n", minor);
 748                 }
 749         }
 750
 751         if (pp->pdev) {
 752                 parport_unregister_device(pp->pdev);
 753                 ida_simple_remove(&ida_index, pp->index);
 754                 pp->pdev = NULL;
 755                 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 756         }
 757
 758         kfree(pp);
 759
 760         return 0;
 761 }
 762
 763 /* No kernel lock held - fine */
 764 static __poll_t pp_poll(struct file *file, poll_table *wait)
 765 {
 766         struct pp_struct *pp = file->private_data;
 767         __poll_t mask = 0;
 768
 769         poll_wait(file, &pp->irq_wait, wait);
 770         if (atomic_read(&pp->irqc))
 771                 mask |= EPOLLIN | EPOLLRDNORM;
 772
 773         return mask;
 774 }
 775
 776 static struct class *ppdev_class;
 777
 778 static const struct file_operations pp_fops = {
 779         .owner          = THIS_MODULE,
 780         .llseek         = no_llseek,
 781         .read           = pp_read,
 782         .write          = pp_write,
 783         .poll           = pp_poll,
 784         .unlocked_ioctl = pp_ioctl,
 785         .compat_ioctl   = compat_ptr_ioctl,
 786         .open           = pp_open,
 787         .release        = pp_release,
 788 };
 789
 790 static void pp_attach(struct parport *port)
 791 {
 792         struct device *ret;
 793
 794         if (devices[port->number])
 795                 return;
 796
 797         ret = device_create(ppdev_class, port->dev,
 798                             MKDEV(PP_MAJOR, port->number), NULL,
 799                             "parport%d", port->number);
 800         if (IS_ERR(ret)) {
 801                 pr_err("Failed to create device parport%d\n",
 802                        port->number);
 803                 return;
 804         }
 805         devices[port->number] = ret;
 806 }
 807
 808 static void pp_detach(struct parport *port)
 809 {
 810         if (!devices[port->number])
 811                 return;
 812
 813         device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 814         devices[port->number] = NULL;
 815 }
 816
 817 static int pp_probe(struct pardevice *par_dev)
 818 {
 819         struct device_driver *drv = par_dev->dev.driver;
 820         int len = strlen(drv->name);
 821
 822         if (strncmp(par_dev->name, drv->name, len))
 823                 return -ENODEV;
 824
 825         return 0;
 826 }
 827
 828 static struct parport_driver pp_driver = {
 829         .name           = CHRDEV,
 830         .probe          = pp_probe,
 831         .match_port     = pp_attach,
 832         .detach         = pp_detach,
 833         .devmodel       = true,
 834 };
 835
 836 static int __init ppdev_init(void)
 837 {
 838         int err = 0;
 839
 840         if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
 841                 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
 842                 return -EIO;
 843         }
 844         ppdev_class = class_create(THIS_MODULE, CHRDEV);
 845         if (IS_ERR(ppdev_class)) {
 846                 err = PTR_ERR(ppdev_class);
 847                 goto out_chrdev;
 848         }
 849         err = parport_register_driver(&pp_driver);
 850         if (err < 0) {
 851                 pr_warn(CHRDEV ": unable to register with parport\n");
 852                 goto out_class;
 853         }
 854
 855         pr_info(PP_VERSION "\n");
 856         goto out;
 857
 858 out_class:
 859         class_destroy(ppdev_class);
 860 out_chrdev:
 861         unregister_chrdev(PP_MAJOR, CHRDEV);
 862 out:
 863         return err;
 864 }
 865
 866 static void __exit ppdev_cleanup(void)
 867 {
 868         /* Clean up all parport stuff */
 869         parport_unregister_driver(&pp_driver);
 870         class_destroy(ppdev_class);
 871         unregister_chrdev(PP_MAJOR, CHRDEV);
 872 }
 873
 874 module_init(ppdev_init);
 875 module_exit(ppdev_cleanup);
 876
 877 MODULE_LICENSE("GPL");
 878 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);