drivers/char/ppdev.c

   1 /*
   2  * linux/drivers/char/ppdev.c
   3  *
   4  * This is the code behind /dev/parport* -- it allows a user-space
   5  * application to use the parport subsystem.
   6  *
   7  * Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; either version
  12  * 2 of the License, or (at your option) any later version.
  13  *
  14  * A /dev/parportx device node represents an arbitrary device
  15  * on port 'x'.  The following operations are possible:
  16  *
  17  * open         do nothing, set up default IEEE 1284 protocol to be COMPAT
  18  * close        release port and unregister device (if necessary)
  19  * ioctl
  20  *   EXCL       register device exclusively (may fail)
  21  *   CLAIM      (register device first time) parport_claim_or_block
  22  *   RELEASE    parport_release
  23  *   SETMODE    set the IEEE 1284 protocol to use for read/write
  24  *   SETPHASE   set the IEEE 1284 phase of a particular mode.  Not to be
  25  *              confused with ioctl(fd, SETPHASER, &stun). ;-)
  26  *   DATADIR    data_forward / data_reverse
  27  *   WDATA      write_data
  28  *   RDATA      read_data
  29  *   WCONTROL   write_control
  30  *   RCONTROL   read_control
  31  *   FCONTROL   frob_control
  32  *   RSTATUS    read_status
  33  *   NEGOT      parport_negotiate
  34  *   YIELD      parport_yield_blocking
  35  *   WCTLONIRQ  on interrupt, set control lines
  36  *   CLRIRQ     clear (and return) interrupt count
  37  *   SETTIME    sets device timeout (struct timeval)
  38  *   GETTIME    gets device timeout (struct timeval)
  39  *   GETMODES   gets hardware supported modes (unsigned int)
  40  *   GETMODE    gets the current IEEE1284 mode
  41  *   GETPHASE   gets the current IEEE1284 phase
  42  *   GETFLAGS   gets current (user-visible) flags
  43  *   SETFLAGS   sets current (user-visible) flags
  44  * read/write   read or write in current IEEE 1284 protocol
  45  * select       wait for interrupt (in readfds)
  46  *
  47  * Changes:
  48  * Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
  49  *
  50  * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
  51  * - On error, copy_from_user and copy_to_user do not return -EFAULT,
  52  *   They return the positive number of bytes *not* copied due to address
  53  *   space errors.
  54  *
  55  * Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
  56  * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
  57  */
  58
  59 #include <linux/module.h>
  60 #include <linux/init.h>
  61 #include <linux/sched.h>
  62 #include <linux/device.h>
  63 #include <linux/ioctl.h>
  64 #include <linux/parport.h>
  65 #include <linux/ctype.h>
  66 #include <linux/poll.h>
  67 #include <linux/slab.h>
  68 #include <linux/major.h>
  69 #include <linux/ppdev.h>
  70 #include <linux/mutex.h>
  71 #include <linux/uaccess.h>
  72 #include <linux/compat.h>
  73
  74 #define PP_VERSION "ppdev: user-space parallel port driver"
  75 #define CHRDEV "ppdev"
  76
  77 struct pp_struct {
  78         struct pardevice *pdev;
  79         wait_queue_head_t irq_wait;
  80         atomic_t irqc;
  81         unsigned int flags;
  82         int irqresponse;
  83         unsigned char irqctl;
  84         struct ieee1284_info state;
  85         struct ieee1284_info saved_state;
  86         long default_inactivity;
  87 };
  88
  89 /* pp_struct.flags bitfields */
  90 #define PP_CLAIMED    (1<<0)
  91 #define PP_EXCL       (1<<1)
  92
  93 /* Other constants */
  94 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
  95 #define PP_BUFFER_SIZE 1024
  96 #define PARDEVICE_MAX 8
  97
  98 /* ROUND_UP macro from fs/select.c */
  99 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
 100
 101 static DEFINE_MUTEX(pp_do_mutex);
 102
 103 /* define fixed sized ioctl cmd for y2038 migration */
 104 #define PPGETTIME32     _IOR(PP_IOCTL, 0x95, s32[2])
 105 #define PPSETTIME32     _IOW(PP_IOCTL, 0x96, s32[2])
 106 #define PPGETTIME64     _IOR(PP_IOCTL, 0x95, s64[2])
 107 #define PPSETTIME64     _IOW(PP_IOCTL, 0x96, s64[2])
 108
 109 static inline void pp_enable_irq(struct pp_struct *pp)
 110 {
 111         struct parport *port = pp->pdev->port;
 112
 113         port->ops->enable_irq(port);
 114 }
 115
 116 static ssize_t pp_read(struct file *file, char __user *buf, size_t count,
 117                        loff_t *ppos)
 118 {
 119         unsigned int minor = iminor(file_inode(file));
 120         struct pp_struct *pp = file->private_data;
 121         char *kbuffer;
 122         ssize_t bytes_read = 0;
 123         struct parport *pport;
 124         int mode;
 125
 126         if (!(pp->flags & PP_CLAIMED)) {
 127                 /* Don't have the port claimed */
 128                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 129                 return -EINVAL;
 130         }
 131
 132         /* Trivial case. */
 133         if (count == 0)
 134                 return 0;
 135
 136         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 137         if (!kbuffer)
 138                 return -ENOMEM;
 139         pport = pp->pdev->port;
 140         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 141
 142         parport_set_timeout(pp->pdev,
 143                             (file->f_flags & O_NONBLOCK) ?
 144                             PARPORT_INACTIVITY_O_NONBLOCK :
 145                             pp->default_inactivity);
 146
 147         while (bytes_read == 0) {
 148                 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
 149
 150                 if (mode == IEEE1284_MODE_EPP) {
 151                         /* various specials for EPP mode */
 152                         int flags = 0;
 153                         size_t (*fn)(struct parport *, void *, size_t, int);
 154
 155                         if (pp->flags & PP_W91284PIC)
 156                                 flags |= PARPORT_W91284PIC;
 157                         if (pp->flags & PP_FASTREAD)
 158                                 flags |= PARPORT_EPP_FAST;
 159                         if (pport->ieee1284.mode & IEEE1284_ADDR)
 160                                 fn = pport->ops->epp_read_addr;
 161                         else
 162                                 fn = pport->ops->epp_read_data;
 163                         bytes_read = (*fn)(pport, kbuffer, need, flags);
 164                 } else {
 165                         bytes_read = parport_read(pport, kbuffer, need);
 166                 }
 167
 168                 if (bytes_read != 0)
 169                         break;
 170
 171                 if (file->f_flags & O_NONBLOCK) {
 172                         bytes_read = -EAGAIN;
 173                         break;
 174                 }
 175
 176                 if (signal_pending(current)) {
 177                         bytes_read = -ERESTARTSYS;
 178                         break;
 179                 }
 180
 181                 cond_resched();
 182         }
 183
 184         parport_set_timeout(pp->pdev, pp->default_inactivity);
 185
 186         if (bytes_read > 0 && copy_to_user(buf, kbuffer, bytes_read))
 187                 bytes_read = -EFAULT;
 188
 189         kfree(kbuffer);
 190         pp_enable_irq(pp);
 191         return bytes_read;
 192 }
 193
 194 static ssize_t pp_write(struct file *file, const char __user *buf,
 195                         size_t count, loff_t *ppos)
 196 {
 197         unsigned int minor = iminor(file_inode(file));
 198         struct pp_struct *pp = file->private_data;
 199         char *kbuffer;
 200         ssize_t bytes_written = 0;
 201         ssize_t wrote;
 202         int mode;
 203         struct parport *pport;
 204
 205         if (!(pp->flags & PP_CLAIMED)) {
 206                 /* Don't have the port claimed */
 207                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 208                 return -EINVAL;
 209         }
 210
 211         kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
 212         if (!kbuffer)
 213                 return -ENOMEM;
 214
 215         pport = pp->pdev->port;
 216         mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
 217
 218         parport_set_timeout(pp->pdev,
 219                             (file->f_flags & O_NONBLOCK) ?
 220                             PARPORT_INACTIVITY_O_NONBLOCK :
 221                             pp->default_inactivity);
 222
 223         while (bytes_written < count) {
 224                 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
 225
 226                 if (copy_from_user(kbuffer, buf + bytes_written, n)) {
 227                         bytes_written = -EFAULT;
 228                         break;
 229                 }
 230
 231                 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
 232                         /* do a fast EPP write */
 233                         if (pport->ieee1284.mode & IEEE1284_ADDR) {
 234                                 wrote = pport->ops->epp_write_addr(pport,
 235                                         kbuffer, n, PARPORT_EPP_FAST);
 236                         } else {
 237                                 wrote = pport->ops->epp_write_data(pport,
 238                                         kbuffer, n, PARPORT_EPP_FAST);
 239                         }
 240                 } else {
 241                         wrote = parport_write(pp->pdev->port, kbuffer, n);
 242                 }
 243
 244                 if (wrote <= 0) {
 245                         if (!bytes_written)
 246                                 bytes_written = wrote;
 247                         break;
 248                 }
 249
 250                 bytes_written += wrote;
 251
 252                 if (file->f_flags & O_NONBLOCK) {
 253                         if (!bytes_written)
 254                                 bytes_written = -EAGAIN;
 255                         break;
 256                 }
 257
 258                 if (signal_pending(current))
 259                         break;
 260
 261                 cond_resched();
 262         }
 263
 264         parport_set_timeout(pp->pdev, pp->default_inactivity);
 265
 266         kfree(kbuffer);
 267         pp_enable_irq(pp);
 268         return bytes_written;
 269 }
 270
 271 static void pp_irq(void *private)
 272 {
 273         struct pp_struct *pp = private;
 274
 275         if (pp->irqresponse) {
 276                 parport_write_control(pp->pdev->port, pp->irqctl);
 277                 pp->irqresponse = 0;
 278         }
 279
 280         atomic_inc(&pp->irqc);
 281         wake_up_interruptible(&pp->irq_wait);
 282 }
 283
 284 static int register_device(int minor, struct pp_struct *pp)
 285 {
 286         struct parport *port;
 287         struct pardevice *pdev = NULL;
 288         char *name;
 289         struct pardev_cb ppdev_cb;
 290
 291         name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
 292         if (name == NULL)
 293                 return -ENOMEM;
 294
 295         port = parport_find_number(minor);
 296         if (!port) {
 297                 printk(KERN_WARNING "%s: no associated port!\n", name);
 298                 kfree(name);
 299                 return -ENXIO;
 300         }
 301
 302         memset(&ppdev_cb, 0, sizeof(ppdev_cb));
 303         ppdev_cb.irq_func = pp_irq;
 304         ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
 305         ppdev_cb.private = pp;
 306         pdev = parport_register_dev_model(port, name, &ppdev_cb, minor);
 307         parport_put_port(port);
 308
 309         if (!pdev) {
 310                 printk(KERN_WARNING "%s: failed to register device!\n", name);
 311                 kfree(name);
 312                 return -ENXIO;
 313         }
 314
 315         pp->pdev = pdev;
 316         dev_dbg(&pdev->dev, "registered pardevice\n");
 317         return 0;
 318 }
 319
 320 static enum ieee1284_phase init_phase(int mode)
 321 {
 322         switch (mode & ~(IEEE1284_DEVICEID
 323                          | IEEE1284_ADDR)) {
 324         case IEEE1284_MODE_NIBBLE:
 325         case IEEE1284_MODE_BYTE:
 326                 return IEEE1284_PH_REV_IDLE;
 327         }
 328         return IEEE1284_PH_FWD_IDLE;
 329 }
 330
 331 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
 332 {
 333         long to_jiffies;
 334
 335         if ((tv_sec < 0) || (tv_usec < 0))
 336                 return -EINVAL;
 337
 338         to_jiffies = usecs_to_jiffies(tv_usec);
 339         to_jiffies += tv_sec * HZ;
 340         if (to_jiffies <= 0)
 341                 return -EINVAL;
 342
 343         pdev->timeout = to_jiffies;
 344         return 0;
 345 }
 346
 347 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 348 {
 349         unsigned int minor = iminor(file_inode(file));
 350         struct pp_struct *pp = file->private_data;
 351         struct parport *port;
 352         void __user *argp = (void __user *)arg;
 353
 354         /* First handle the cases that don't take arguments. */
 355         switch (cmd) {
 356         case PPCLAIM:
 357             {
 358                 struct ieee1284_info *info;
 359                 int ret;
 360
 361                 if (pp->flags & PP_CLAIMED) {
 362                         dev_dbg(&pp->pdev->dev, "you've already got it!\n");
 363                         return -EINVAL;
 364                 }
 365
 366                 /* Deferred device registration. */
 367                 if (!pp->pdev) {
 368                         int err = register_device(minor, pp);
 369
 370                         if (err)
 371                                 return err;
 372                 }
 373
 374                 ret = parport_claim_or_block(pp->pdev);
 375                 if (ret < 0)
 376                         return ret;
 377
 378                 pp->flags |= PP_CLAIMED;
 379
 380                 /* For interrupt-reporting to work, we need to be
 381                  * informed of each interrupt. */
 382                 pp_enable_irq(pp);
 383
 384                 /* We may need to fix up the state machine. */
 385                 info = &pp->pdev->port->ieee1284;
 386                 pp->saved_state.mode = info->mode;
 387                 pp->saved_state.phase = info->phase;
 388                 info->mode = pp->state.mode;
 389                 info->phase = pp->state.phase;
 390                 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
 391                 parport_set_timeout(pp->pdev, pp->default_inactivity);
 392
 393                 return 0;
 394             }
 395         case PPEXCL:
 396                 if (pp->pdev) {
 397                         dev_dbg(&pp->pdev->dev,
 398                                 "too late for PPEXCL; already registered\n");
 399                         if (pp->flags & PP_EXCL)
 400                                 /* But it's not really an error. */
 401                                 return 0;
 402                         /* There's no chance of making the driver happy. */
 403                         return -EINVAL;
 404                 }
 405
 406                 /* Just remember to register the device exclusively
 407                  * when we finally do the registration. */
 408                 pp->flags |= PP_EXCL;
 409                 return 0;
 410         case PPSETMODE:
 411             {
 412                 int mode;
 413
 414                 if (copy_from_user(&mode, argp, sizeof(mode)))
 415                         return -EFAULT;
 416                 /* FIXME: validate mode */
 417                 pp->state.mode = mode;
 418                 pp->state.phase = init_phase(mode);
 419
 420                 if (pp->flags & PP_CLAIMED) {
 421                         pp->pdev->port->ieee1284.mode = mode;
 422                         pp->pdev->port->ieee1284.phase = pp->state.phase;
 423                 }
 424
 425                 return 0;
 426             }
 427         case PPGETMODE:
 428             {
 429                 int mode;
 430
 431                 if (pp->flags & PP_CLAIMED)
 432                         mode = pp->pdev->port->ieee1284.mode;
 433                 else
 434                         mode = pp->state.mode;
 435
 436                 if (copy_to_user(argp, &mode, sizeof(mode)))
 437                         return -EFAULT;
 438                 return 0;
 439             }
 440         case PPSETPHASE:
 441             {
 442                 int phase;
 443
 444                 if (copy_from_user(&phase, argp, sizeof(phase)))
 445                         return -EFAULT;
 446
 447                 /* FIXME: validate phase */
 448                 pp->state.phase = phase;
 449
 450                 if (pp->flags & PP_CLAIMED)
 451                         pp->pdev->port->ieee1284.phase = phase;
 452
 453                 return 0;
 454             }
 455         case PPGETPHASE:
 456             {
 457                 int phase;
 458
 459                 if (pp->flags & PP_CLAIMED)
 460                         phase = pp->pdev->port->ieee1284.phase;
 461                 else
 462                         phase = pp->state.phase;
 463                 if (copy_to_user(argp, &phase, sizeof(phase)))
 464                         return -EFAULT;
 465                 return 0;
 466             }
 467         case PPGETMODES:
 468             {
 469                 unsigned int modes;
 470
 471                 port = parport_find_number(minor);
 472                 if (!port)
 473                         return -ENODEV;
 474
 475                 modes = port->modes;
 476                 parport_put_port(port);
 477                 if (copy_to_user(argp, &modes, sizeof(modes)))
 478                         return -EFAULT;
 479                 return 0;
 480             }
 481         case PPSETFLAGS:
 482             {
 483                 int uflags;
 484
 485                 if (copy_from_user(&uflags, argp, sizeof(uflags)))
 486                         return -EFAULT;
 487                 pp->flags &= ~PP_FLAGMASK;
 488                 pp->flags |= (uflags & PP_FLAGMASK);
 489                 return 0;
 490             }
 491         case PPGETFLAGS:
 492             {
 493                 int uflags;
 494
 495                 uflags = pp->flags & PP_FLAGMASK;
 496                 if (copy_to_user(argp, &uflags, sizeof(uflags)))
 497                         return -EFAULT;
 498                 return 0;
 499             }
 500         }       /* end switch() */
 501
 502         /* Everything else requires the port to be claimed, so check
 503          * that now. */
 504         if ((pp->flags & PP_CLAIMED) == 0) {
 505                 pr_debug(CHRDEV "%x: claim the port first\n", minor);
 506                 return -EINVAL;
 507         }
 508
 509         port = pp->pdev->port;
 510         switch (cmd) {
 511                 struct ieee1284_info *info;
 512                 unsigned char reg;
 513                 unsigned char mask;
 514                 int mode;
 515                 s32 time32[2];
 516                 s64 time64[2];
 517                 struct timespec64 ts;
 518                 int ret;
 519
 520         case PPRSTATUS:
 521                 reg = parport_read_status(port);
 522                 if (copy_to_user(argp, &reg, sizeof(reg)))
 523                         return -EFAULT;
 524                 return 0;
 525         case PPRDATA:
 526                 reg = parport_read_data(port);
 527                 if (copy_to_user(argp, &reg, sizeof(reg)))
 528                         return -EFAULT;
 529                 return 0;
 530         case PPRCONTROL:
 531                 reg = parport_read_control(port);
 532                 if (copy_to_user(argp, &reg, sizeof(reg)))
 533                         return -EFAULT;
 534                 return 0;
 535         case PPYIELD:
 536                 parport_yield_blocking(pp->pdev);
 537                 return 0;
 538
 539         case PPRELEASE:
 540                 /* Save the state machine's state. */
 541                 info = &pp->pdev->port->ieee1284;
 542                 pp->state.mode = info->mode;
 543                 pp->state.phase = info->phase;
 544                 info->mode = pp->saved_state.mode;
 545                 info->phase = pp->saved_state.phase;
 546                 parport_release(pp->pdev);
 547                 pp->flags &= ~PP_CLAIMED;
 548                 return 0;
 549
 550         case PPWCONTROL:
 551                 if (copy_from_user(&reg, argp, sizeof(reg)))
 552                         return -EFAULT;
 553                 parport_write_control(port, reg);
 554                 return 0;
 555
 556         case PPWDATA:
 557                 if (copy_from_user(&reg, argp, sizeof(reg)))
 558                         return -EFAULT;
 559                 parport_write_data(port, reg);
 560                 return 0;
 561
 562         case PPFCONTROL:
 563                 if (copy_from_user(&mask, argp,
 564                                    sizeof(mask)))
 565                         return -EFAULT;
 566                 if (copy_from_user(&reg, 1 + (unsigned char __user *) arg,
 567                                    sizeof(reg)))
 568                         return -EFAULT;
 569                 parport_frob_control(port, mask, reg);
 570                 return 0;
 571
 572         case PPDATADIR:
 573                 if (copy_from_user(&mode, argp, sizeof(mode)))
 574                         return -EFAULT;
 575                 if (mode)
 576                         port->ops->data_reverse(port);
 577                 else
 578                         port->ops->data_forward(port);
 579                 return 0;
 580
 581         case PPNEGOT:
 582                 if (copy_from_user(&mode, argp, sizeof(mode)))
 583                         return -EFAULT;
 584                 switch ((ret = parport_negotiate(port, mode))) {
 585                 case 0: break;
 586                 case -1: /* handshake failed, peripheral not IEEE 1284 */
 587                         ret = -EIO;
 588                         break;
 589                 case 1:  /* handshake succeeded, peripheral rejected mode */
 590                         ret = -ENXIO;
 591                         break;
 592                 }
 593                 pp_enable_irq(pp);
 594                 return ret;
 595
 596         case PPWCTLONIRQ:
 597                 if (copy_from_user(&reg, argp, sizeof(reg)))
 598                         return -EFAULT;
 599
 600                 /* Remember what to set the control lines to, for next
 601                  * time we get an interrupt. */
 602                 pp->irqctl = reg;
 603                 pp->irqresponse = 1;
 604                 return 0;
 605
 606         case PPCLRIRQ:
 607                 ret = atomic_read(&pp->irqc);
 608                 if (copy_to_user(argp, &ret, sizeof(ret)))
 609                         return -EFAULT;
 610                 atomic_sub(ret, &pp->irqc);
 611                 return 0;
 612
 613         case PPSETTIME32:
 614                 if (copy_from_user(time32, argp, sizeof(time32)))
 615                         return -EFAULT;
 616
 617                 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
 618
 619         case PPSETTIME64:
 620                 if (copy_from_user(time64, argp, sizeof(time64)))
 621                         return -EFAULT;
 622
 623                 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
 624
 625         case PPGETTIME32:
 626                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 627                 time32[0] = ts.tv_sec;
 628                 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
 629                 if ((time32[0] < 0) || (time32[1] < 0))
 630                         return -EINVAL;
 631
 632                 if (copy_to_user(argp, time32, sizeof(time32)))
 633                         return -EFAULT;
 634
 635                 return 0;
 636
 637         case PPGETTIME64:
 638                 jiffies_to_timespec64(pp->pdev->timeout, &ts);
 639                 time64[0] = ts.tv_sec;
 640                 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
 641                 if ((time64[0] < 0) || (time64[1] < 0))
 642                         return -EINVAL;
 643
 644                 if (copy_to_user(argp, time64, sizeof(time64)))
 645                         return -EFAULT;
 646
 647                 return 0;
 648
 649         default:
 650                 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
 651                 return -EINVAL;
 652         }
 653
 654         /* Keep the compiler happy */
 655         return 0;
 656 }
 657
 658 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 659 {
 660         long ret;
 661
 662         mutex_lock(&pp_do_mutex);
 663         ret = pp_do_ioctl(file, cmd, arg);
 664         mutex_unlock(&pp_do_mutex);
 665         return ret;
 666 }
 667
 668 #ifdef CONFIG_COMPAT
 669 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
 670                             unsigned long arg)
 671 {
 672         return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 673 }
 674 #endif
 675
 676 static int pp_open(struct inode *inode, struct file *file)
 677 {
 678         unsigned int minor = iminor(inode);
 679         struct pp_struct *pp;
 680
 681         if (minor >= PARPORT_MAX)
 682                 return -ENXIO;
 683
 684         pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
 685         if (!pp)
 686                 return -ENOMEM;
 687
 688         pp->state.mode = IEEE1284_MODE_COMPAT;
 689         pp->state.phase = init_phase(pp->state.mode);
 690         pp->flags = 0;
 691         pp->irqresponse = 0;
 692         atomic_set(&pp->irqc, 0);
 693         init_waitqueue_head(&pp->irq_wait);
 694
 695         /* Defer the actual device registration until the first claim.
 696          * That way, we know whether or not the driver wants to have
 697          * exclusive access to the port (PPEXCL).
 698          */
 699         pp->pdev = NULL;
 700         file->private_data = pp;
 701
 702         return 0;
 703 }
 704
 705 static int pp_release(struct inode *inode, struct file *file)
 706 {
 707         unsigned int minor = iminor(inode);
 708         struct pp_struct *pp = file->private_data;
 709         int compat_negot;
 710
 711         compat_negot = 0;
 712         if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
 713             (pp->state.mode != IEEE1284_MODE_COMPAT)) {
 714                 struct ieee1284_info *info;
 715
 716                 /* parport released, but not in compatibility mode */
 717                 parport_claim_or_block(pp->pdev);
 718                 pp->flags |= PP_CLAIMED;
 719                 info = &pp->pdev->port->ieee1284;
 720                 pp->saved_state.mode = info->mode;
 721                 pp->saved_state.phase = info->phase;
 722                 info->mode = pp->state.mode;
 723                 info->phase = pp->state.phase;
 724                 compat_negot = 1;
 725         } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
 726             (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
 727                 compat_negot = 2;
 728         }
 729         if (compat_negot) {
 730                 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
 731                 dev_dbg(&pp->pdev->dev,
 732                         "negotiated back to compatibility mode because user-space forgot\n");
 733         }
 734
 735         if (pp->flags & PP_CLAIMED) {
 736                 struct ieee1284_info *info;
 737
 738                 info = &pp->pdev->port->ieee1284;
 739                 pp->state.mode = info->mode;
 740                 pp->state.phase = info->phase;
 741                 info->mode = pp->saved_state.mode;
 742                 info->phase = pp->saved_state.phase;
 743                 parport_release(pp->pdev);
 744                 if (compat_negot != 1) {
 745                         pr_debug(CHRDEV "%x: released pardevice "
 746                                 "because user-space forgot\n", minor);
 747                 }
 748         }
 749
 750         if (pp->pdev) {
 751                 const char *name = pp->pdev->name;
 752
 753                 parport_unregister_device(pp->pdev);
 754                 kfree(name);
 755                 pp->pdev = NULL;
 756                 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
 757         }
 758
 759         kfree(pp);
 760
 761         return 0;
 762 }
 763
 764 /* No kernel lock held - fine */
 765 static unsigned int pp_poll(struct file *file, poll_table *wait)
 766 {
 767         struct pp_struct *pp = file->private_data;
 768         unsigned int mask = 0;
 769
 770         poll_wait(file, &pp->irq_wait, wait);
 771         if (atomic_read(&pp->irqc))
 772                 mask |= POLLIN | POLLRDNORM;
 773
 774         return mask;
 775 }
 776
 777 static struct class *ppdev_class;
 778
 779 static const struct file_operations pp_fops = {
 780         .owner          = THIS_MODULE,
 781         .llseek         = no_llseek,
 782         .read           = pp_read,
 783         .write          = pp_write,
 784         .poll           = pp_poll,
 785         .unlocked_ioctl = pp_ioctl,
 786 #ifdef CONFIG_COMPAT
 787         .compat_ioctl   = pp_compat_ioctl,
 788 #endif
 789         .open           = pp_open,
 790         .release        = pp_release,
 791 };
 792
 793 static void pp_attach(struct parport *port)
 794 {
 795         device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
 796                       NULL, "parport%d", port->number);
 797 }
 798
 799 static void pp_detach(struct parport *port)
 800 {
 801         device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
 802 }
 803
 804 static int pp_probe(struct pardevice *par_dev)
 805 {
 806         struct device_driver *drv = par_dev->dev.driver;
 807         int len = strlen(drv->name);
 808
 809         if (strncmp(par_dev->name, drv->name, len))
 810                 return -ENODEV;
 811
 812         return 0;
 813 }
 814
 815 static struct parport_driver pp_driver = {
 816         .name           = CHRDEV,
 817         .probe          = pp_probe,
 818         .match_port     = pp_attach,
 819         .detach         = pp_detach,
 820         .devmodel       = true,
 821 };
 822
 823 static int __init ppdev_init(void)
 824 {
 825         int err = 0;
 826
 827         if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
 828                 printk(KERN_WARNING CHRDEV ": unable to get major %d\n",
 829                        PP_MAJOR);
 830                 return -EIO;
 831         }
 832         ppdev_class = class_create(THIS_MODULE, CHRDEV);
 833         if (IS_ERR(ppdev_class)) {
 834                 err = PTR_ERR(ppdev_class);
 835                 goto out_chrdev;
 836         }
 837         err = parport_register_driver(&pp_driver);
 838         if (err < 0) {
 839                 printk(KERN_WARNING CHRDEV ": unable to register with parport\n");
 840                 goto out_class;
 841         }
 842
 843         printk(KERN_INFO PP_VERSION "\n");
 844         goto out;
 845
 846 out_class:
 847         class_destroy(ppdev_class);
 848 out_chrdev:
 849         unregister_chrdev(PP_MAJOR, CHRDEV);
 850 out:
 851         return err;
 852 }
 853
 854 static void __exit ppdev_cleanup(void)
 855 {
 856         /* Clean up all parport stuff */
 857         parport_unregister_driver(&pp_driver);
 858         class_destroy(ppdev_class);
 859         unregister_chrdev(PP_MAJOR, CHRDEV);
 860 }
 861
 862 module_init(ppdev_init);
 863 module_exit(ppdev_cleanup);
 864
 865 MODULE_LICENSE("GPL");
 866 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);