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ppdev.c
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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 <[email protected]>
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 <[email protected]> 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 <[email protected]>, 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 
73 #define PP_VERSION "ppdev: user-space parallel port driver"
74 #define CHRDEV "ppdev"
75 
76 struct pp_struct {
77  struct pardevice * pdev;
80  unsigned int flags;
82  unsigned char irqctl;
86 };
87 
88 /* pp_struct.flags bitfields */
89 #define PP_CLAIMED (1<<0)
90 #define PP_EXCL (1<<1)
91 
92 /* Other constants */
93 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
94 #define PP_BUFFER_SIZE 1024
95 #define PARDEVICE_MAX 8
96 
97 /* ROUND_UP macro from fs/select.c */
98 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
99 
100 static DEFINE_MUTEX(pp_do_mutex);
101 static inline void pp_enable_irq (struct pp_struct *pp)
102 {
103  struct parport *port = pp->pdev->port;
104  port->ops->enable_irq (port);
105 }
106 
107 static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
108  loff_t * ppos)
109 {
110  unsigned int minor = iminor(file->f_path.dentry->d_inode);
111  struct pp_struct *pp = file->private_data;
112  char * kbuffer;
113  ssize_t bytes_read = 0;
114  struct parport *pport;
115  int mode;
116 
117  if (!(pp->flags & PP_CLAIMED)) {
118  /* Don't have the port claimed */
119  pr_debug(CHRDEV "%x: claim the port first\n", minor);
120  return -EINVAL;
121  }
122 
123  /* Trivial case. */
124  if (count == 0)
125  return 0;
126 
127  kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
128  if (!kbuffer) {
129  return -ENOMEM;
130  }
131  pport = pp->pdev->port;
132  mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
133 
135  (file->f_flags & O_NONBLOCK) ?
137  pp->default_inactivity);
138 
139  while (bytes_read == 0) {
140  ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
141 
142  if (mode == IEEE1284_MODE_EPP) {
143  /* various specials for EPP mode */
144  int flags = 0;
145  size_t (*fn)(struct parport *, void *, size_t, int);
146 
147  if (pp->flags & PP_W91284PIC) {
148  flags |= PARPORT_W91284PIC;
149  }
150  if (pp->flags & PP_FASTREAD) {
151  flags |= PARPORT_EPP_FAST;
152  }
153  if (pport->ieee1284.mode & IEEE1284_ADDR) {
154  fn = pport->ops->epp_read_addr;
155  } else {
156  fn = pport->ops->epp_read_data;
157  }
158  bytes_read = (*fn)(pport, kbuffer, need, flags);
159  } else {
160  bytes_read = parport_read (pport, kbuffer, need);
161  }
162 
163  if (bytes_read != 0)
164  break;
165 
166  if (file->f_flags & O_NONBLOCK) {
167  bytes_read = -EAGAIN;
168  break;
169  }
170 
171  if (signal_pending (current)) {
172  bytes_read = -ERESTARTSYS;
173  break;
174  }
175 
176  cond_resched();
177  }
178 
180 
181  if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
182  bytes_read = -EFAULT;
183 
184  kfree (kbuffer);
185  pp_enable_irq (pp);
186  return bytes_read;
187 }
188 
189 static ssize_t pp_write (struct file * file, const char __user * buf,
190  size_t count, loff_t * ppos)
191 {
192  unsigned int minor = iminor(file->f_path.dentry->d_inode);
193  struct pp_struct *pp = file->private_data;
194  char * kbuffer;
195  ssize_t bytes_written = 0;
196  ssize_t wrote;
197  int mode;
198  struct parport *pport;
199 
200  if (!(pp->flags & PP_CLAIMED)) {
201  /* Don't have the port claimed */
202  pr_debug(CHRDEV "%x: claim the port first\n", minor);
203  return -EINVAL;
204  }
205 
206  kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
207  if (!kbuffer) {
208  return -ENOMEM;
209  }
210  pport = pp->pdev->port;
211  mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
212 
214  (file->f_flags & O_NONBLOCK) ?
216  pp->default_inactivity);
217 
218  while (bytes_written < count) {
219  ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
220 
221  if (copy_from_user (kbuffer, buf + bytes_written, n)) {
222  bytes_written = -EFAULT;
223  break;
224  }
225 
226  if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
227  /* do a fast EPP write */
228  if (pport->ieee1284.mode & IEEE1284_ADDR) {
229  wrote = pport->ops->epp_write_addr (pport,
230  kbuffer, n, PARPORT_EPP_FAST);
231  } else {
232  wrote = pport->ops->epp_write_data (pport,
233  kbuffer, n, PARPORT_EPP_FAST);
234  }
235  } else {
236  wrote = parport_write (pp->pdev->port, kbuffer, n);
237  }
238 
239  if (wrote <= 0) {
240  if (!bytes_written) {
241  bytes_written = wrote;
242  }
243  break;
244  }
245 
246  bytes_written += wrote;
247 
248  if (file->f_flags & O_NONBLOCK) {
249  if (!bytes_written)
250  bytes_written = -EAGAIN;
251  break;
252  }
253 
254  if (signal_pending (current)) {
255  if (!bytes_written) {
256  bytes_written = -EINTR;
257  }
258  break;
259  }
260 
261  cond_resched();
262  }
263 
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);
282 }
283 
284 static int register_device (int minor, struct pp_struct *pp)
285 {
286  struct parport *port;
287  struct pardevice * pdev = NULL;
288  char *name;
289  int fl;
290 
291  name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
292  if (name == NULL)
293  return -ENOMEM;
294 
295  port = parport_find_number (minor);
296  if (!port) {
297  printk (KERN_WARNING "%s: no associated port!\n", name);
298  kfree (name);
299  return -ENXIO;
300  }
301 
302  fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
303  pdev = parport_register_device (port, name, NULL,
304  NULL, pp_irq, fl, pp);
305  parport_put_port (port);
306 
307  if (!pdev) {
308  printk (KERN_WARNING "%s: failed to register device!\n", name);
309  kfree (name);
310  return -ENXIO;
311  }
312 
313  pp->pdev = pdev;
314  pr_debug("%s: registered pardevice\n", name);
315  return 0;
316 }
317 
318 static enum ieee1284_phase init_phase (int mode)
319 {
320  switch (mode & ~(IEEE1284_DEVICEID
321  | IEEE1284_ADDR)) {
323  case IEEE1284_MODE_BYTE:
324  return IEEE1284_PH_REV_IDLE;
325  }
326  return IEEE1284_PH_FWD_IDLE;
327 }
328 
329 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
330 {
331  unsigned int minor = iminor(file->f_path.dentry->d_inode);
332  struct pp_struct *pp = file->private_data;
333  struct parport * port;
334  void __user *argp = (void __user *)arg;
335 
336  /* First handle the cases that don't take arguments. */
337  switch (cmd) {
338  case PPCLAIM:
339  {
340  struct ieee1284_info *info;
341  int ret;
342 
343  if (pp->flags & PP_CLAIMED) {
344  pr_debug(CHRDEV "%x: you've already got it!\n", minor);
345  return -EINVAL;
346  }
347 
348  /* Deferred device registration. */
349  if (!pp->pdev) {
350  int err = register_device (minor, pp);
351  if (err) {
352  return err;
353  }
354  }
355 
356  ret = parport_claim_or_block (pp->pdev);
357  if (ret < 0)
358  return ret;
359 
360  pp->flags |= PP_CLAIMED;
361 
362  /* For interrupt-reporting to work, we need to be
363  * informed of each interrupt. */
364  pp_enable_irq (pp);
365 
366  /* We may need to fix up the state machine. */
367  info = &pp->pdev->port->ieee1284;
368  pp->saved_state.mode = info->mode;
369  pp->saved_state.phase = info->phase;
370  info->mode = pp->state.mode;
371  info->phase = pp->state.phase;
374 
375  return 0;
376  }
377  case PPEXCL:
378  if (pp->pdev) {
379  pr_debug(CHRDEV "%x: too late for PPEXCL; "
380  "already registered\n", minor);
381  if (pp->flags & PP_EXCL)
382  /* But it's not really an error. */
383  return 0;
384  /* There's no chance of making the driver happy. */
385  return -EINVAL;
386  }
387 
388  /* Just remember to register the device exclusively
389  * when we finally do the registration. */
390  pp->flags |= PP_EXCL;
391  return 0;
392  case PPSETMODE:
393  {
394  int mode;
395  if (copy_from_user (&mode, argp, sizeof (mode)))
396  return -EFAULT;
397  /* FIXME: validate mode */
398  pp->state.mode = mode;
399  pp->state.phase = init_phase (mode);
400 
401  if (pp->flags & PP_CLAIMED) {
402  pp->pdev->port->ieee1284.mode = mode;
403  pp->pdev->port->ieee1284.phase = pp->state.phase;
404  }
405 
406  return 0;
407  }
408  case PPGETMODE:
409  {
410  int mode;
411 
412  if (pp->flags & PP_CLAIMED) {
413  mode = pp->pdev->port->ieee1284.mode;
414  } else {
415  mode = pp->state.mode;
416  }
417  if (copy_to_user (argp, &mode, sizeof (mode))) {
418  return -EFAULT;
419  }
420  return 0;
421  }
422  case PPSETPHASE:
423  {
424  int phase;
425  if (copy_from_user (&phase, argp, sizeof (phase))) {
426  return -EFAULT;
427  }
428  /* FIXME: validate phase */
429  pp->state.phase = phase;
430 
431  if (pp->flags & PP_CLAIMED) {
432  pp->pdev->port->ieee1284.phase = phase;
433  }
434 
435  return 0;
436  }
437  case PPGETPHASE:
438  {
439  int phase;
440 
441  if (pp->flags & PP_CLAIMED) {
442  phase = pp->pdev->port->ieee1284.phase;
443  } else {
444  phase = pp->state.phase;
445  }
446  if (copy_to_user (argp, &phase, sizeof (phase))) {
447  return -EFAULT;
448  }
449  return 0;
450  }
451  case PPGETMODES:
452  {
453  unsigned int modes;
454 
455  port = parport_find_number (minor);
456  if (!port)
457  return -ENODEV;
458 
459  modes = port->modes;
460  parport_put_port(port);
461  if (copy_to_user (argp, &modes, sizeof (modes))) {
462  return -EFAULT;
463  }
464  return 0;
465  }
466  case PPSETFLAGS:
467  {
468  int uflags;
469 
470  if (copy_from_user (&uflags, argp, sizeof (uflags))) {
471  return -EFAULT;
472  }
473  pp->flags &= ~PP_FLAGMASK;
474  pp->flags |= (uflags & PP_FLAGMASK);
475  return 0;
476  }
477  case PPGETFLAGS:
478  {
479  int uflags;
480 
481  uflags = pp->flags & PP_FLAGMASK;
482  if (copy_to_user (argp, &uflags, sizeof (uflags))) {
483  return -EFAULT;
484  }
485  return 0;
486  }
487  } /* end switch() */
488 
489  /* Everything else requires the port to be claimed, so check
490  * that now. */
491  if ((pp->flags & PP_CLAIMED) == 0) {
492  pr_debug(CHRDEV "%x: claim the port first\n", minor);
493  return -EINVAL;
494  }
495 
496  port = pp->pdev->port;
497  switch (cmd) {
498  struct ieee1284_info *info;
499  unsigned char reg;
500  unsigned char mask;
501  int mode;
502  int ret;
503  struct timeval par_timeout;
504  long to_jiffies;
505 
506  case PPRSTATUS:
507  reg = parport_read_status (port);
508  if (copy_to_user (argp, &reg, sizeof (reg)))
509  return -EFAULT;
510  return 0;
511  case PPRDATA:
512  reg = parport_read_data (port);
513  if (copy_to_user (argp, &reg, sizeof (reg)))
514  return -EFAULT;
515  return 0;
516  case PPRCONTROL:
517  reg = parport_read_control (port);
518  if (copy_to_user (argp, &reg, sizeof (reg)))
519  return -EFAULT;
520  return 0;
521  case PPYIELD:
522  parport_yield_blocking (pp->pdev);
523  return 0;
524 
525  case PPRELEASE:
526  /* Save the state machine's state. */
527  info = &pp->pdev->port->ieee1284;
528  pp->state.mode = info->mode;
529  pp->state.phase = info->phase;
530  info->mode = pp->saved_state.mode;
531  info->phase = pp->saved_state.phase;
532  parport_release (pp->pdev);
533  pp->flags &= ~PP_CLAIMED;
534  return 0;
535 
536  case PPWCONTROL:
537  if (copy_from_user (&reg, argp, sizeof (reg)))
538  return -EFAULT;
539  parport_write_control (port, reg);
540  return 0;
541 
542  case PPWDATA:
543  if (copy_from_user (&reg, argp, sizeof (reg)))
544  return -EFAULT;
545  parport_write_data (port, reg);
546  return 0;
547 
548  case PPFCONTROL:
549  if (copy_from_user (&mask, argp,
550  sizeof (mask)))
551  return -EFAULT;
552  if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
553  sizeof (reg)))
554  return -EFAULT;
555  parport_frob_control (port, mask, reg);
556  return 0;
557 
558  case PPDATADIR:
559  if (copy_from_user (&mode, argp, sizeof (mode)))
560  return -EFAULT;
561  if (mode)
562  port->ops->data_reverse (port);
563  else
564  port->ops->data_forward (port);
565  return 0;
566 
567  case PPNEGOT:
568  if (copy_from_user (&mode, argp, sizeof (mode)))
569  return -EFAULT;
570  switch ((ret = parport_negotiate (port, mode))) {
571  case 0: break;
572  case -1: /* handshake failed, peripheral not IEEE 1284 */
573  ret = -EIO;
574  break;
575  case 1: /* handshake succeeded, peripheral rejected mode */
576  ret = -ENXIO;
577  break;
578  }
579  pp_enable_irq (pp);
580  return ret;
581 
582  case PPWCTLONIRQ:
583  if (copy_from_user (&reg, argp, sizeof (reg)))
584  return -EFAULT;
585 
586  /* Remember what to set the control lines to, for next
587  * time we get an interrupt. */
588  pp->irqctl = reg;
589  pp->irqresponse = 1;
590  return 0;
591 
592  case PPCLRIRQ:
593  ret = atomic_read (&pp->irqc);
594  if (copy_to_user (argp, &ret, sizeof (ret)))
595  return -EFAULT;
596  atomic_sub (ret, &pp->irqc);
597  return 0;
598 
599  case PPSETTIME:
600  if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
601  return -EFAULT;
602  }
603  /* Convert to jiffies, place in pp->pdev->timeout */
604  if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
605  return -EINVAL;
606  }
607  to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
608  to_jiffies += par_timeout.tv_sec * (long)HZ;
609  if (to_jiffies <= 0) {
610  return -EINVAL;
611  }
612  pp->pdev->timeout = to_jiffies;
613  return 0;
614 
615  case PPGETTIME:
616  to_jiffies = pp->pdev->timeout;
617  memset(&par_timeout, 0, sizeof(par_timeout));
618  par_timeout.tv_sec = to_jiffies / HZ;
619  par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
620  if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
621  return -EFAULT;
622  return 0;
623 
624  default:
625  pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
626  return -EINVAL;
627  }
628 
629  /* Keep the compiler happy */
630  return 0;
631 }
632 
633 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
634 {
635  long ret;
636  mutex_lock(&pp_do_mutex);
637  ret = pp_do_ioctl(file, cmd, arg);
638  mutex_unlock(&pp_do_mutex);
639  return ret;
640 }
641 
642 static int pp_open (struct inode * inode, struct file * file)
643 {
644  unsigned int minor = iminor(inode);
645  struct pp_struct *pp;
646 
647  if (minor >= PARPORT_MAX)
648  return -ENXIO;
649 
650  pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
651  if (!pp)
652  return -ENOMEM;
653 
654  pp->state.mode = IEEE1284_MODE_COMPAT;
655  pp->state.phase = init_phase (pp->state.mode);
656  pp->flags = 0;
657  pp->irqresponse = 0;
658  atomic_set (&pp->irqc, 0);
660 
661  /* Defer the actual device registration until the first claim.
662  * That way, we know whether or not the driver wants to have
663  * exclusive access to the port (PPEXCL).
664  */
665  pp->pdev = NULL;
666  file->private_data = pp;
667 
668  return 0;
669 }
670 
671 static int pp_release (struct inode * inode, struct file * file)
672 {
673  unsigned int minor = iminor(inode);
674  struct pp_struct *pp = file->private_data;
675  int compat_negot;
676 
677  compat_negot = 0;
678  if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
679  (pp->state.mode != IEEE1284_MODE_COMPAT)) {
680  struct ieee1284_info *info;
681 
682  /* parport released, but not in compatibility mode */
684  pp->flags |= PP_CLAIMED;
685  info = &pp->pdev->port->ieee1284;
686  pp->saved_state.mode = info->mode;
687  pp->saved_state.phase = info->phase;
688  info->mode = pp->state.mode;
689  info->phase = pp->state.phase;
690  compat_negot = 1;
691  } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
692  (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
693  compat_negot = 2;
694  }
695  if (compat_negot) {
697  pr_debug(CHRDEV "%x: negotiated back to compatibility "
698  "mode because user-space forgot\n", minor);
699  }
700 
701  if (pp->flags & PP_CLAIMED) {
702  struct ieee1284_info *info;
703 
704  info = &pp->pdev->port->ieee1284;
705  pp->state.mode = info->mode;
706  pp->state.phase = info->phase;
707  info->mode = pp->saved_state.mode;
708  info->phase = pp->saved_state.phase;
709  parport_release (pp->pdev);
710  if (compat_negot != 1) {
711  pr_debug(CHRDEV "%x: released pardevice "
712  "because user-space forgot\n", minor);
713  }
714  }
715 
716  if (pp->pdev) {
717  const char *name = pp->pdev->name;
719  kfree (name);
720  pp->pdev = NULL;
721  pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
722  }
723 
724  kfree (pp);
725 
726  return 0;
727 }
728 
729 /* No kernel lock held - fine */
730 static unsigned int pp_poll (struct file * file, poll_table * wait)
731 {
732  struct pp_struct *pp = file->private_data;
733  unsigned int mask = 0;
734 
735  poll_wait (file, &pp->irq_wait, wait);
736  if (atomic_read (&pp->irqc))
737  mask |= POLLIN | POLLRDNORM;
738 
739  return mask;
740 }
741 
742 static struct class *ppdev_class;
743 
744 static const struct file_operations pp_fops = {
745  .owner = THIS_MODULE,
746  .llseek = no_llseek,
747  .read = pp_read,
748  .write = pp_write,
749  .poll = pp_poll,
750  .unlocked_ioctl = pp_ioctl,
751  .open = pp_open,
752  .release = pp_release,
753 };
754 
755 static void pp_attach(struct parport *port)
756 {
757  device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
758  NULL, "parport%d", port->number);
759 }
760 
761 static void pp_detach(struct parport *port)
762 {
763  device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
764 }
765 
766 static struct parport_driver pp_driver = {
767  .name = CHRDEV,
768  .attach = pp_attach,
769  .detach = pp_detach,
770 };
771 
772 static int __init ppdev_init (void)
773 {
774  int err = 0;
775 
776  if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
777  printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
778  PP_MAJOR);
779  return -EIO;
780  }
781  ppdev_class = class_create(THIS_MODULE, CHRDEV);
782  if (IS_ERR(ppdev_class)) {
783  err = PTR_ERR(ppdev_class);
784  goto out_chrdev;
785  }
786  err = parport_register_driver(&pp_driver);
787  if (err < 0) {
788  printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
789  goto out_class;
790  }
791 
792  printk (KERN_INFO PP_VERSION "\n");
793  goto out;
794 
795 out_class:
796  class_destroy(ppdev_class);
797 out_chrdev:
798  unregister_chrdev(PP_MAJOR, CHRDEV);
799 out:
800  return err;
801 }
802 
803 static void __exit ppdev_cleanup (void)
804 {
805  /* Clean up all parport stuff */
806  parport_unregister_driver(&pp_driver);
807  class_destroy(ppdev_class);
808  unregister_chrdev (PP_MAJOR, CHRDEV);
809 }
810 
811 module_init(ppdev_init);
812 module_exit(ppdev_cleanup);
813 
814 MODULE_LICENSE("GPL");