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 <[email protected]>
   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 <[email protected]> 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 <[email protected]>, 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_free_name;
 300         }
 301
 302         index = ida_alloc(&ida_index, GFP_KERNEL);
 303         if (index < 0) {
 304                 pr_warn("%s: failed to get index!\n", name);
 305                 rc = index;
 306                 goto err_put_port;
 307         }
 308
 309         memset(&ppdev_cb, 0, sizeof(ppdev_cb));
 310         ppdev_cb.irq_func = pp_irq;
 311         ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 312         ppdev_cb.private = pp;
 313         pdev = parport_register_dev_model(port, name, &ppdev_cb, index);
 314
 315         if (!pdev) {
 316                 pr_warn("%s: failed to register device!\n", name);
 317                 rc = -ENXIO;
 318                 ida_free(&ida_index, index);
 319                 goto err_put_port;
 320         }
 321
 322         pp->pdev = pdev;
 323         pp->index = index;
 324         dev_dbg(&pdev->dev, "registered pardevice\n");
 325 err_put_port:
 326         parport_put_port(port);
 327 err_free_name:
 328         kfree(name);
 329         return rc;
 330 }
 331
 332 static enum ieee1284_phase init_phase(int mode)
 333 {
 334         switch (mode & ~(IEEE1284_DEVICEID
 335                          | IEEE1284_ADDR)) {
 336         case IEEE1284_MODE_NIBBLE:
 337         case IEEE1284_MODE_BYTE:
 338                 return IEEE1284_PH_REV_IDLE;
 339         }
 340         return IEEE1284_PH_FWD_IDLE;
 341 }
 342
 343 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
 344 {
 345         long to_jiffies;
 346
 347         if ((tv_sec < 0) || (tv_usec < 0))
 348                 return -EINVAL;
 349
 350         to_jiffies = usecs_to_jiffies(tv_usec);
 351         to_jiffies += tv_sec * HZ;
 352         if (to_jiffies <= 0)
 353                 return -EINVAL;
 354
 355         pdev->timeout = to_jiffies;
 356         return 0;
 357 }
 358
 359 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 360 {
 361         unsigned int minor = iminor(file_inode(file));
 362         struct pp_struct *pp = file->private_data;
 363         struct parport *port;
 364         void __user *argp = (void __user *)arg;
 365         struct ieee1284_info *info;
 366         unsigned char reg;
 367         unsigned char mask;
 368         int mode;
 369         s32 time32[2];
 370         s64 time64[2];
 371         struct timespec64 ts;
 372         int ret;
 373
 374         /* First handle the cases that don't take arguments. */
 375         switch (cmd) {
 376         case PPCLAIM:
 377             {
 378                 if (pp->flags & PP_CLAIMED) {
 379                         dev_dbg(&pp->pdev->dev, "you've already got it!\n");
 380                         return -EINVAL;
 381                 }
 382
 383                 /* Deferred device registration. */
 384                 if (!pp->pdev) {
 385                         int err = register_device(minor, pp);
 386
 387                         if (err)
 388                                 return err;
 389                 }
 390
 391                 ret = parport_claim_or_block(pp->pdev);
 392                 if (ret < 0)
 393                         return ret;
 394
 395                 pp->flags |= PP_CLAIMED;
 396
 397                 /* For interrupt-reporting to work, we need to be
 398                  * informed of each interrupt. */
 399                 pp_enable_irq(pp);
 400
 401                 /* We may need to fix up the state machine. */
 402                 info = &pp->pdev->port->ieee1284;
 403                 pp->saved_state.mode = info->mode;
 404                 pp->saved_state.phase = info->phase;
 405                 info->mode = pp->state.mode;
 406                 info->phase = pp->state.phase;
 407                 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
 408                 parport_set_timeout(pp->pdev, pp->default_inactivity);
 409
 410                 return 0;
 411             }
 412         case PPEXCL:
 413                 if (pp->pdev) {
 414                         dev_dbg(&pp->pdev->dev,
 415                                 "too late for PPEXCL; already registered\n");
 416                         if (pp->flags & PP_EXCL)
 417                                 /* But it's not really an error. */
 418                                 return 0;
 419                         /* There's no chance of making the driver happy. */
 420                         return -EINVAL;
 421                 }
 422
 423                 /* Just remember to register the device exclusively
 424                  * when we finally do the registration. */
 425                 pp->flags |= PP_EXCL;
 426                 return 0;
 427         case PPSETMODE:
 428             {
 429                 int mode;
 430
 431                 if (copy_from_user(&mode, argp, sizeof(mode)))
 432                         return -EFAULT;
 433                 /* FIXME: validate mode */
 434                 pp->state.mode = mode;
 435                 pp->state.phase = init_phase(mode);
 436
 437                 if (pp->flags & PP_CLAIMED) {
 438                         pp->pdev->port->ieee1284.mode = mode;
 439                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 440                 }
 441
 442                 return 0;
 443             }
 444         case PPGETMODE:
 445             {
 446                 int mode;
 447
 448                 if (pp->flags & PP_CLAIMED)
 449                         mode = pp->pdev->port->ieee1284.mode;
 450                 else
 451                         mode = pp->state.mode;
 452
 453                 if (copy_to_user(argp, &mode, sizeof(mode)))
 454                         return -EFAULT;
 455                 return 0;
 456             }
 457         case PPSETPHASE:
 458             {
 459                 int phase;
 460
 461                 if (copy_from_user(&phase, argp, sizeof(phase)))
 462                         return -EFAULT;
 463
 464                 /* FIXME: validate phase */
 465                 pp->state.phase = phase;
 466
 467                 if (pp->flags & PP_CLAIMED)
 468                         pp->pdev->port->ieee1284.phase = phase;
 469
 470                 return 0;
 471             }
 472         case PPGETPHASE:
 473             {
 474                 int phase;
 475
 476                 if (pp->flags & PP_CLAIMED)
 477                         phase = pp->pdev->port->ieee1284.phase;
 478                 else
 479                         phase = pp->state.phase;
 480                 if (copy_to_user(argp, &phase, sizeof(phase)))
 481                         return -EFAULT;
 482                 return 0;
 483             }
 484         case PPGETMODES:
 485             {
 486                 unsigned int modes;
 487
 488                 port = parport_find_number(minor);
 489                 if (!port)
 490                         return -ENODEV;
 491
 492                 modes = port->modes;
 493                 parport_put_port(port);
 494                 if (copy_to_user(argp, &modes, sizeof(modes)))
 495                         return -EFAULT;
 496                 return 0;
 497             }
 498         case PPSETFLAGS:
 499             {
 500                 int uflags;
 501
 502                 if (copy_from_user(&uflags, argp, sizeof(uflags)))
 503                         return -EFAULT;
 504                 pp->flags &= ~PP_FLAGMASK;
 505                 pp->flags |= (uflags & PP_FLAGMASK);
 506                 return 0;
 507             }
 508         case PPGETFLAGS:
 509             {
 510                 int uflags;
 511
 512                 uflags = pp->flags & PP_FLAGMASK;
 513                 if (copy_to_user(argp, &uflags, sizeof(uflags)))
 514                         return -EFAULT;
 515                 return 0;
 516             }
 517         }       /* end switch() */
 518
 519         /* Everything else requires the port to be claimed, so check
 520          * that now. */
 521         if ((pp->flags & PP_CLAIMED) == 0) {
 522                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 523                 return -EINVAL;
 524         }
 525
 526         port = pp->pdev->port;
 527         switch (cmd) {
 528         case PPRSTATUS:
 529                 reg = parport_read_status(port);
 530                 if (copy_to_user(argp, &reg, sizeof(reg)))
 531                         return -EFAULT;
 532                 return 0;
 533         case PPRDATA:
 534                 reg = parport_read_data(port);
 535                 if (copy_to_user(argp, &reg, sizeof(reg)))
 536                         return -EFAULT;
 537                 return 0;
 538         case PPRCONTROL:
 539                 reg = parport_read_control(port);
 540                 if (copy_to_user(argp, &reg, sizeof(reg)))
 541                         return -EFAULT;
 542                 return 0;
 543         case PPYIELD:
 544                 parport_yield_blocking(pp->pdev);
 545                 return 0;
 546
 547         case PPRELEASE:
 548                 /* Save the state machine's state. */
 549                 info = &pp->pdev->port->ieee1284;
 550                 pp->state.mode = info->mode;
 551                 pp->state.phase = info->phase;
 552                 info->mode = pp->saved_state.mode;
 553                 info->phase = pp->saved_state.phase;
 554                 parport_release(pp->pdev);
 555                 pp->flags &= ~PP_CLAIMED;
 556                 return 0;
 557
 558         case PPWCONTROL:
 559                 if (copy_from_user(&reg, argp, sizeof(reg)))
 560                         return -EFAULT;
 561                 parport_write_control(port, reg);
 562                 return 0;
 563
 564         case PPWDATA:
 565                 if (copy_from_user(&reg, argp, sizeof(reg)))
 566                         return -EFAULT;
 567                 parport_write_data(port, reg);
 568                 return 0;
 569
 570         case PPFCONTROL:
 571                 if (copy_from_user(&mask, argp,
 572                                    sizeof(mask)))
 573                         return -EFAULT;
 574                 if (copy_from_user(&reg, 1 + (unsigned char __user *) arg,
 575                                    sizeof(reg)))
 576                         return -EFAULT;
 577                 parport_frob_control(port, mask, reg);
 578                 return 0;
 579
 580         case PPDATADIR:
 581                 if (copy_from_user(&mode, argp, sizeof(mode)))
 582                         return -EFAULT;
 583                 if (mode)
 584                         port->ops->data_reverse(port);
 585                 else
 586                         port->ops->data_forward(port);
 587                 return 0;
 588
 589         case PPNEGOT:
 590                 if (copy_from_user(&mode, argp, sizeof(mode)))
 591                         return -EFAULT;
 592                 switch ((ret = parport_negotiate(port, mode))) {
 593                 case 0: break;
 594                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 595                         ret = -EIO;
 596                         break;
 597                 case 1:  /* handshake succeeded, peripheral rejected mode */
 598                         ret = -ENXIO;
 599                         break;
 600                 }
 601                 pp_enable_irq(pp);
 602                 return ret;
 603
 604         case PPWCTLONIRQ:
 605                 if (copy_from_user(&reg, argp, sizeof(reg)))
 606                         return -EFAULT;
 607
 608                 /* Remember what to set the control lines to, for next
 609                  * time we get an interrupt. */
 610                 pp->irqctl = reg;
 611                 pp->irqresponse = 1;
 612                 return 0;
 613
 614         case PPCLRIRQ:
 615                 ret = atomic_read(&pp->irqc);
 616                 if (copy_to_user(argp, &ret, sizeof(ret)))
 617                         return -EFAULT;
 618                 atomic_sub(ret, &pp->irqc);
 619                 return 0;
 620
 621         case PPSETTIME32:
 622                 if (copy_from_user(time32, argp, sizeof(time32)))
 623                         return -EFAULT;
 624
 625                 if ((time32[0] < 0) || (time32[1] < 0))
 626                         return -EINVAL;
 627
 628                 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
 629
 630         case PPSETTIME64:
 631                 if (copy_from_user(time64, argp, sizeof(time64)))
 632                         return -EFAULT;
 633
 634                 if ((time64[0] < 0) || (time64[1] < 0))
 635                         return -EINVAL;
 636
 637                 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
 638                         time64[1] >>= 32;
 639
 640                 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
 641
 642         case PPGETTIME32:
 643                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 644                 time32[0] = ts.tv_sec;
 645                 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
 646
 647                 if (copy_to_user(argp, time32, sizeof(time32)))
 648                         return -EFAULT;
 649
 650                 return 0;
 651
 652         case PPGETTIME64:
 653                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 654                 time64[0] = ts.tv_sec;
 655                 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
 656
 657                 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
 658                         time64[1] <<= 32;
 659
 660                 if (copy_to_user(argp, time64, sizeof(time64)))
 661                         return -EFAULT;
 662
 663                 return 0;
 664
 665         default:
 666                 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
 667                 return -EINVAL;
 668         }
 669
 670         /* Keep the compiler happy */
 671         return 0;
 672 }
 673
 674 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 675 {
 676         long ret;
 677
 678         mutex_lock(&pp_do_mutex);
 679         ret = pp_do_ioctl(file, cmd, arg);
 680         mutex_unlock(&pp_do_mutex);
 681         return ret;
 682 }
 683
 684 static int pp_open(struct inode *inode, struct file *file)
 685 {
 686         unsigned int minor = iminor(inode);
 687         struct pp_struct *pp;
 688
 689         if (minor >= PARPORT_MAX)
 690                 return -ENXIO;
 691
 692         pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
 693         if (!pp)
 694                 return -ENOMEM;
 695
 696         pp->state.mode = IEEE1284_MODE_COMPAT;
 697         pp->state.phase = init_phase(pp->state.mode);
 698         pp->flags = 0;
 699         pp->irqresponse = 0;
 700         atomic_set(&pp->irqc, 0);
 701         init_waitqueue_head(&pp->irq_wait);
 702
 703         /* Defer the actual device registration until the first claim.
 704          * That way, we know whether or not the driver wants to have
 705          * exclusive access to the port (PPEXCL).
 706          */
 707         pp->pdev = NULL;
 708         file->private_data = pp;
 709
 710         return 0;
 711 }
 712
 713 static int pp_release(struct inode *inode, struct file *file)
 714 {
 715         unsigned int minor = iminor(inode);
 716         struct pp_struct *pp = file->private_data;
 717         int compat_negot;
 718
 719         compat_negot = 0;
 720         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 721             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 722                 struct ieee1284_info *info;
 723
 724                 /* parport released, but not in compatibility mode */
 725                 parport_claim_or_block(pp->pdev);
 726                 pp->flags |= PP_CLAIMED;
 727                 info = &pp->pdev->port->ieee1284;
 728                 pp->saved_state.mode = info->mode;
 729                 pp->saved_state.phase = info->phase;
 730                 info->mode = pp->state.mode;
 731                 info->phase = pp->state.phase;
 732                 compat_negot = 1;
 733         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 734             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 735                 compat_negot = 2;
 736         }
 737         if (compat_negot) {
 738                 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
 739                 dev_dbg(&pp->pdev->dev,
 740                         "negotiated back to compatibility mode because user-space forgot\n");
 741         }
 742
 743         if ((pp->flags & PP_CLAIMED) && pp->pdev) {
 744                 struct ieee1284_info *info;
 745
 746                 info = &pp->pdev->port->ieee1284;
 747                 pp->state.mode = info->mode;
 748                 pp->state.phase = info->phase;
 749                 info->mode = pp->saved_state.mode;
 750                 info->phase = pp->saved_state.phase;
 751                 parport_release(pp->pdev);
 752                 if (compat_negot != 1) {
 753                         pr_debug(CHRDEV "%x: released pardevice "
 754                                 "because user-space forgot\n", minor);
 755                 }
 756         }
 757
 758         if (pp->pdev) {
 759                 parport_unregister_device(pp->pdev);
 760                 ida_free(&ida_index, pp->index);
 761                 pp->pdev = NULL;
 762                 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 763         }
 764
 765         kfree(pp);
 766
 767         return 0;
 768 }
 769
 770 /* No kernel lock held - fine */
 771 static __poll_t pp_poll(struct file *file, poll_table *wait)
 772 {
 773         struct pp_struct *pp = file->private_data;
 774         __poll_t mask = 0;
 775
 776         poll_wait(file, &pp->irq_wait, wait);
 777         if (atomic_read(&pp->irqc))
 778                 mask |= EPOLLIN | EPOLLRDNORM;
 779
 780         return mask;
 781 }
 782
 783 static const struct class ppdev_class = {
 784         .name = CHRDEV,
 785 };
 786
 787 static const struct file_operations pp_fops = {
 788         .owner          = THIS_MODULE,
 789         .read           = pp_read,
 790         .write          = pp_write,
 791         .poll           = pp_poll,
 792         .unlocked_ioctl = pp_ioctl,
 793         .compat_ioctl   = compat_ptr_ioctl,
 794         .open           = pp_open,
 795         .release        = pp_release,
 796 };
 797
 798 static void pp_attach(struct parport *port)
 799 {
 800         struct device *ret;
 801
 802         if (devices[port->number])
 803                 return;
 804
 805         ret = device_create(&ppdev_class, port->dev,
 806                             MKDEV(PP_MAJOR, port->number), NULL,
 807                             "parport%d", port->number);
 808         if (IS_ERR(ret)) {
 809                 pr_err("Failed to create device parport%d\n",
 810                        port->number);
 811                 return;
 812         }
 813         devices[port->number] = ret;
 814 }
 815
 816 static void pp_detach(struct parport *port)
 817 {
 818         if (!devices[port->number])
 819                 return;
 820
 821         device_destroy(&ppdev_class, MKDEV(PP_MAJOR, port->number));
 822         devices[port->number] = NULL;
 823 }
 824
 825 static int pp_probe(struct pardevice *par_dev)
 826 {
 827         struct device_driver *drv = par_dev->dev.driver;
 828         int len = strlen(drv->name);
 829
 830         if (strncmp(par_dev->name, drv->name, len))
 831                 return -ENODEV;
 832
 833         return 0;
 834 }
 835
 836 static struct parport_driver pp_driver = {
 837         .name           = CHRDEV,
 838         .probe          = pp_probe,
 839         .match_port     = pp_attach,
 840         .detach         = pp_detach,
 841 };
 842
 843 static int __init ppdev_init(void)
 844 {
 845         int err = 0;
 846
 847         if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
 848                 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
 849                 return -EIO;
 850         }
 851         err = class_register(&ppdev_class);
 852         if (err)
 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_unregister(&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_unregister(&ppdev_class);
 877         unregister_chrdev(PP_MAJOR, CHRDEV);
 878 }
 879
 880 module_init(ppdev_init);
 881 module_exit(ppdev_cleanup);
 882
 883 MODULE_DESCRIPTION("Support for user-space parallel port device drivers");
 884 MODULE_LICENSE("GPL");
 885 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);