aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/ppdev.c
blob: 7af7a7e6b9c2e570ff53eff4152e5f61d6cf7738 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
/*
 * linux/drivers/char/ppdev.c
 *
 * This is the code behind /dev/parport* -- it allows a user-space
 * application to use the parport subsystem.
 *
 * Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * A /dev/parportx device node represents an arbitrary device
 * on port 'x'.  The following operations are possible:
 *
 * open		do nothing, set up default IEEE 1284 protocol to be COMPAT
 * close	release port and unregister device (if necessary)
 * ioctl
 *   EXCL	register device exclusively (may fail)
 *   CLAIM	(register device first time) parport_claim_or_block
 *   RELEASE	parport_release
 *   SETMODE	set the IEEE 1284 protocol to use for read/write
 *   SETPHASE	set the IEEE 1284 phase of a particular mode.  Not to be
 *              confused with ioctl(fd, SETPHASER, &stun). ;-)
 *   DATADIR	data_forward / data_reverse
 *   WDATA	write_data
 *   RDATA	read_data
 *   WCONTROL	write_control
 *   RCONTROL	read_control
 *   FCONTROL	frob_control
 *   RSTATUS	read_status
 *   NEGOT	parport_negotiate
 *   YIELD	parport_yield_blocking
 *   WCTLONIRQ	on interrupt, set control lines
 *   CLRIRQ	clear (and return) interrupt count
 *   SETTIME	sets device timeout (struct timeval)
 *   GETTIME	gets device timeout (struct timeval)
 *   GETMODES	gets hardware supported modes (unsigned int)
 *   GETMODE	gets the current IEEE1284 mode
 *   GETPHASE   gets the current IEEE1284 phase
 *   GETFLAGS   gets current (user-visible) flags
 *   SETFLAGS   sets current (user-visible) flags
 * read/write	read or write in current IEEE 1284 protocol
 * select	wait for interrupt (in readfds)
 *
 * Changes:
 * Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
 *
 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
 * - On error, copy_from_user and copy_to_user do not return -EFAULT,
 *   They return the positive number of bytes *not* copied due to address
 *   space errors.
 *
 * Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
 * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/ioctl.h>
#include <linux/parport.h>
#include <linux/ctype.h>
#include <linux/poll.h>
#include <linux/major.h>
#include <linux/ppdev.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>

#define PP_VERSION "ppdev: user-space parallel port driver"
#define CHRDEV "ppdev"

struct pp_struct {
	struct pardevice * pdev;
	wait_queue_head_t irq_wait;
	atomic_t irqc;
	unsigned int flags;
	int irqresponse;
	unsigned char irqctl;
	struct ieee1284_info state;
	struct ieee1284_info saved_state;
	long default_inactivity;
};

/* pp_struct.flags bitfields */
#define PP_CLAIMED    (1<<0)
#define PP_EXCL       (1<<1)

/* Other constants */
#define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
#define PP_BUFFER_SIZE 1024
#define PARDEVICE_MAX 8

/* ROUND_UP macro from fs/select.c */
#define ROUND_UP(x,y) (((x)+(y)-1)/(y))

static inline void pp_enable_irq (struct pp_struct *pp)
{
	struct parport *port = pp->pdev->port;
	port->ops->enable_irq (port);
}

static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
			loff_t * ppos)
{
	unsigned int minor = iminor(file->f_path.dentry->d_inode);
	struct pp_struct *pp = file->private_data;
	char * kbuffer;
	ssize_t bytes_read = 0;
	struct parport *pport;
	int mode;

	if (!(pp->flags & PP_CLAIMED)) {
		/* Don't have the port claimed */
		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
			minor);
		return -EINVAL;
	}

	/* Trivial case. */
	if (count == 0)
		return 0;

	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
	if (!kbuffer) {
		return -ENOMEM;
	}
	pport = pp->pdev->port;
	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);

	parport_set_timeout (pp->pdev,
			     (file->f_flags & O_NONBLOCK) ?
			     PARPORT_INACTIVITY_O_NONBLOCK :
			     pp->default_inactivity);

	while (bytes_read == 0) {
		ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);

		if (mode == IEEE1284_MODE_EPP) {
			/* various specials for EPP mode */
			int flags = 0;
			size_t (*fn)(struct parport *, void *, size_t, int);

			if (pp->flags & PP_W91284PIC) {
				flags |= PARPORT_W91284PIC;
			}
			if (pp->flags & PP_FASTREAD) {
				flags |= PARPORT_EPP_FAST;
			}
			if (pport->ieee1284.mode & IEEE1284_ADDR) {
				fn = pport->ops->epp_read_addr;
			} else {
				fn = pport->ops->epp_read_data;
			}
			bytes_read = (*fn)(pport, kbuffer, need, flags);
		} else {
			bytes_read = parport_read (pport, kbuffer, need);
		}

		if (bytes_read != 0)
			break;

		if (file->f_flags & O_NONBLOCK) {
			bytes_read = -EAGAIN;
			break;
		}

		if (signal_pending (current)) {
			bytes_read = -ERESTARTSYS;
			break;
		}

		cond_resched();
	}

	parport_set_timeout (pp->pdev, pp->default_inactivity);

	if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
		bytes_read = -EFAULT;

	kfree (kbuffer);
	pp_enable_irq (pp);
	return bytes_read;
}

static ssize_t pp_write (struct file * file, const char __user * buf,
			 size_t count, loff_t * ppos)
{
	unsigned int minor = iminor(file->f_path.dentry->d_inode);
	struct pp_struct *pp = file->private_data;
	char * kbuffer;
	ssize_t bytes_written = 0;
	ssize_t wrote;
	int mode;
	struct parport *pport;

	if (!(pp->flags & PP_CLAIMED)) {
		/* Don't have the port claimed */
		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
			minor);
		return -EINVAL;
	}

	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
	if (!kbuffer) {
		return -ENOMEM;
	}
	pport = pp->pdev->port;
	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);

	parport_set_timeout (pp->pdev,
			     (file->f_flags & O_NONBLOCK) ?
			     PARPORT_INACTIVITY_O_NONBLOCK :
			     pp->default_inactivity);

	while (bytes_written < count) {
		ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);

		if (copy_from_user (kbuffer, buf + bytes_written, n)) {
			bytes_written = -EFAULT;
			break;
		}

		if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
			/* do a fast EPP write */
			if (pport->ieee1284.mode & IEEE1284_ADDR) {
				wrote = pport->ops->epp_write_addr (pport,
					kbuffer, n, PARPORT_EPP_FAST);
			} else {
				wrote = pport->ops->epp_write_data (pport,
					kbuffer, n, PARPORT_EPP_FAST);
			}
		} else {
			wrote = parport_write (pp->pdev->port, kbuffer, n);
		}

		if (wrote <= 0) {
			if (!bytes_written) {
				bytes_written = wrote;
			}
			break;
		}

		bytes_written += wrote;

		if (file->f_flags & O_NONBLOCK) {
			if (!bytes_written)
				bytes_written = -EAGAIN;
			break;
		}

		if (signal_pending (current)) {
			if (!bytes_written) {
				bytes_written = -EINTR;
			}
			break;
		}

		cond_resched();
	}

	parport_set_timeout (pp->pdev, pp->default_inactivity);

	kfree (kbuffer);
	pp_enable_irq (pp);
	return bytes_written;
}

static void pp_irq (void *private)
{
	struct pp_struct *pp = private;

	if (pp->irqresponse) {
		parport_write_control (pp->pdev->port, pp->irqctl);
		pp->irqresponse = 0;
	}

	atomic_inc (&pp->irqc);
	wake_up_interruptible (&pp->irq_wait);
}

static int register_device (int minor, struct pp_struct *pp)
{
	struct parport *port;
	struct pardevice * pdev = NULL;
	char *name;
	int fl;

	name = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
	if (name == NULL)
		return -ENOMEM;

	sprintf (name, CHRDEV "%x", minor);

	port = parport_find_number (minor);
	if (!port) {
		printk (KERN_WARNING "%s: no associated port!\n", name);
		kfree (name);
		return -ENXIO;
	}

	fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
	pdev = parport_register_device (port, name, NULL,
					NULL, pp_irq, fl, pp);
	parport_put_port (port);

	if (!pdev) {
		printk (KERN_WARNING "%s: failed to register device!\n", name);
		kfree (name);
		return -ENXIO;
	}

	pp->pdev = pdev;
	printk (KERN_DEBUG "%s: registered pardevice\n", name);
	return 0;
}

static enum ieee1284_phase init_phase (int mode)
{
	switch (mode & ~(IEEE1284_DEVICEID
			 | IEEE1284_ADDR)) {
	case IEEE1284_MODE_NIBBLE:
	case IEEE1284_MODE_BYTE:
		return IEEE1284_PH_REV_IDLE;
	}
	return IEEE1284_PH_FWD_IDLE;
}

static int pp_ioctl(struct inode *inode, struct file *file,
		    unsigned int cmd, unsigned long arg)
{
	unsigned int minor = iminor(inode);
	struct pp_struct *pp = file->private_data;
	struct parport * port;
	void __user *argp = (void __user *)arg;

	/* First handle the cases that don't take arguments. */
	switch (cmd) {
	case PPCLAIM:
	    {
		struct ieee1284_info *info;
		int ret;

		if (pp->flags & PP_CLAIMED) {
			printk (KERN_DEBUG CHRDEV
				"%x: you've already got it!\n", minor);
			return -EINVAL;
		}

		/* Deferred device registration. */
		if (!pp->pdev) {
			int err = register_device (minor, pp);
			if (err) {
				return err;
			}
		}

		ret = parport_claim_or_block (pp->pdev);
		if (ret < 0)
			return ret;

		pp->flags |= PP_CLAIMED;

		/* For interrupt-reporting to work, we need to be
		 * informed of each interrupt. */
		pp_enable_irq (pp);

		/* We may need to fix up the state machine. */
		info = &pp->pdev->port->ieee1284;
		pp->saved_state.mode = info->mode;
		pp->saved_state.phase = info->phase;
		info->mode = pp->state.mode;
		info->phase = pp->state.phase;
		pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
		parport_set_timeout (pp->pdev, pp->default_inactivity);

		return 0;
	    }
	case PPEXCL:
		if (pp->pdev) {
			printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
				"already registered\n", minor);
			if (pp->flags & PP_EXCL)
				/* But it's not really an error. */
				return 0;
			/* There's no chance of making the driver happy. */
			return -EINVAL;
		}

		/* Just remember to register the device exclusively
		 * when we finally do the registration. */
		pp->flags |= PP_EXCL;
		return 0;
	case PPSETMODE:
	    {
		int mode;
		if (copy_from_user (&mode, argp, sizeof (mode)))
			return -EFAULT;
		/* FIXME: validate mode */
		pp->state.mode = mode;
		pp->state.phase = init_phase (mode);

		if (pp->flags & PP_CLAIMED) {
			pp->pdev->port->ieee1284.mode = mode;
			pp->pdev->port->ieee1284.phase = pp->state.phase;
		}

		return 0;
	    }
	case PPGETMODE:
	    {
		int mode;

		if (pp->flags & PP_CLAIMED) {
			mode = pp->pdev->port->ieee1284.mode;
		} else {
			mode = pp->state.mode;
		}
		if (copy_to_user (argp, &mode, sizeof (mode))) {
			return -EFAULT;
		}
		return 0;
	    }
	case PPSETPHASE:
	    {
		int phase;
		if (copy_from_user (&phase, argp, sizeof (phase))) {
			return -EFAULT;
		}
		/* FIXME: validate phase */
		pp->state.phase = phase;

		if (pp->flags & PP_CLAIMED) {
			pp->pdev->port->ieee1284.phase = phase;
		}

		return 0;
	    }
	case PPGETPHASE:
	    {
		int phase;

		if (pp->flags & PP_CLAIMED) {
			phase = pp->pdev->port->ieee1284.phase;
		} else {
			phase = pp->state.phase;
		}
		if (copy_to_user (argp, &phase, sizeof (phase))) {
			return -EFAULT;
		}
		return 0;
	    }
	case PPGETMODES:
	    {
		unsigned int modes;

		port = parport_find_number (minor);
		if (!port)
			return -ENODEV;

		modes = port->modes;
		if (copy_to_user (argp, &modes, sizeof (modes))) {
			return -EFAULT;
		}
		return 0;
	    }
	case PPSETFLAGS:
	    {
		int uflags;

		if (copy_from_user (&uflags, argp, sizeof (uflags))) {
			return -EFAULT;
		}
		pp->flags &= ~PP_FLAGMASK;
		pp->flags |= (uflags & PP_FLAGMASK);
		return 0;
	    }
	case PPGETFLAGS:
	    {
		int uflags;

		uflags = pp->flags & PP_FLAGMASK;
		if (copy_to_user (argp, &uflags, sizeof (uflags))) {
			return -EFAULT;
		}
		return 0;
	    }
	}	/* end switch() */

	/* Everything else requires the port to be claimed, so check
	 * that now. */
	if ((pp->flags & PP_CLAIMED) == 0) {
		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
			minor);
		return -EINVAL;
	}

	port = pp->pdev->port;
	switch (cmd) {
		struct ieee1284_info *info;
		unsigned char reg;
		unsigned char mask;
		int mode;
		int ret;
		struct timeval par_timeout;
		long to_jiffies;

	case PPRSTATUS:
		reg = parport_read_status (port);
		if (copy_to_user (argp, &reg, sizeof (reg)))
			return -EFAULT;
		return 0;
	case PPRDATA:
		reg = parport_read_data (port);
		if (copy_to_user (argp, &reg, sizeof (reg)))
			return -EFAULT;
		return 0;
	case PPRCONTROL:
		reg = parport_read_control (port);
		if (copy_to_user (argp, &reg, sizeof (reg)))
			return -EFAULT;
		return 0;
	case PPYIELD:
		parport_yield_blocking (pp->pdev);
		return 0;

	case PPRELEASE:
		/* Save the state machine's state. */
		info = &pp->pdev->port->ieee1284;
		pp->state.mode = info->mode;
		pp->state.phase = info->phase;
		info->mode = pp->saved_state.mode;
		info->phase = pp->saved_state.phase;
		parport_release (pp->pdev);
		pp->flags &= ~PP_CLAIMED;
		return 0;

	case PPWCONTROL:
		if (copy_from_user (&reg, argp, sizeof (reg)))
			return -EFAULT;
		parport_write_control (port, reg);
		return 0;

	case PPWDATA:
		if (copy_from_user (&reg, argp, sizeof (reg)))
			return -EFAULT;
		parport_write_data (port, reg);
		return 0;

	case PPFCONTROL:
		if (copy_from_user (&mask, argp,
				    sizeof (mask)))
			return -EFAULT;
		if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
				    sizeof (reg)))
			return -EFAULT;
		parport_frob_control (port, mask, reg);
		return 0;

	case PPDATADIR:
		if (copy_from_user (&mode, argp, sizeof (mode)))
			return -EFAULT;
		if (mode)
			port->ops->data_reverse (port);
		else
			port->ops->data_forward (port);
		return 0;

	case PPNEGOT:
		if (copy_from_user (&mode, argp, sizeof (mode)))
			return -EFAULT;
		switch ((ret = parport_negotiate (port, mode))) {
		case 0: break;
		case -1: /* handshake failed, peripheral not IEEE 1284 */
			ret = -EIO;
			break;
		case 1:  /* handshake succeeded, peripheral rejected mode */
			ret = -ENXIO;
			break;
		}
		pp_enable_irq (pp);
		return ret;

	case PPWCTLONIRQ:
		if (copy_from_user (&reg, argp, sizeof (reg)))
			return -EFAULT;

		/* Remember what to set the control lines to, for next
		 * time we get an interrupt. */
		pp->irqctl = reg;
		pp->irqresponse = 1;
		return 0;

	case PPCLRIRQ:
		ret = atomic_read (&pp->irqc);
		if (copy_to_user (argp, &ret, sizeof (ret)))
			return -EFAULT;
		atomic_sub (ret, &pp->irqc);
		return 0;

	case PPSETTIME:
		if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
			return -EFAULT;
		}
		/* Convert to jiffies, place in pp->pdev->timeout */
		if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
			return -EINVAL;
		}
		to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
		to_jiffies += par_timeout.tv_sec * (long)HZ;
		if (to_jiffies <= 0) {
			return -EINVAL;
		}
		pp->pdev->timeout = to_jiffies;
		return 0;

	case PPGETTIME:
		to_jiffies = pp->pdev->timeout;
		par_timeout.tv_sec = to_jiffies / HZ;
		par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
		if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
			return -EFAULT;
		return 0;

	default:
		printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
			cmd);
		return -EINVAL;
	}

	/* Keep the compiler happy */
	return 0;
}

static int pp_open (struct inode * inode, struct file * file)
{
	unsigned int minor = iminor(inode);
	struct pp_struct *pp;

	cycle_kernel_lock();
	if (minor >= PARPORT_MAX)
		return -ENXIO;

	pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
	if (!pp)
		return -ENOMEM;

	pp->state.mode = IEEE1284_MODE_COMPAT;
	pp->state.phase = init_phase (pp->state.mode);
	pp->flags = 0;
	pp->irqresponse = 0;
	atomic_set (&pp->irqc, 0);
	init_waitqueue_head (&pp->irq_wait);

	/* Defer the actual device registration until the first claim.
	 * That way, we know whether or not the driver wants to have
	 * exclusive access to the port (PPEXCL).
	 */
	pp->pdev = NULL;
	file->private_data = pp;

	return 0;
}

static int pp_release (struct inode * inode, struct file * file)
{
	unsigned int minor = iminor(inode);
	struct pp_struct *pp = file->private_data;
	int compat_negot;

	compat_negot = 0;
	if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
	    (pp->state.mode != IEEE1284_MODE_COMPAT)) {
	    	struct ieee1284_info *info;

		/* parport released, but not in compatibility mode */
		parport_claim_or_block (pp->pdev);
		pp->flags |= PP_CLAIMED;
		info = &pp->pdev->port->ieee1284;
		pp->saved_state.mode = info->mode;
		pp->saved_state.phase = info->phase;
		info->mode = pp->state.mode;
		info->phase = pp->state.phase;
		compat_negot = 1;
	} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
	    (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
		compat_negot = 2;
	}
	if (compat_negot) {
		parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
		printk (KERN_DEBUG CHRDEV
			"%x: negotiated back to compatibility mode because "
			"user-space forgot\n", minor);
	}

	if (pp->flags & PP_CLAIMED) {
		struct ieee1284_info *info;

		info = &pp->pdev->port->ieee1284;
		pp->state.mode = info->mode;
		pp->state.phase = info->phase;
		info->mode = pp->saved_state.mode;
		info->phase = pp->saved_state.phase;
		parport_release (pp->pdev);
		if (compat_negot != 1) {
			printk (KERN_DEBUG CHRDEV "%x: released pardevice "
				"because user-space forgot\n", minor);
		}
	}

	if (pp->pdev) {
		const char *name = pp->pdev->name;
		parport_unregister_device (pp->pdev);
		kfree (name);
		pp->pdev = NULL;
		printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
			minor);
	}

	kfree (pp);

	return 0;
}

/* No kernel lock held - fine */
static unsigned int pp_poll (struct file * file, poll_table * wait)
{
	struct pp_struct *pp = file->private_data;
	unsigned int mask = 0;

	poll_wait (file, &pp->irq_wait, wait);
	if (atomic_read (&pp->irqc))
		mask |= POLLIN | POLLRDNORM;

	return mask;
}

static struct class *ppdev_class;

static const struct file_operations pp_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= pp_read,
	.write		= pp_write,
	.poll		= pp_poll,
	.ioctl		= pp_ioctl,
	.open		= pp_open,
	.release	= pp_release,
};

static void pp_attach(struct parport *port)
{
	device_create_drvdata(ppdev_class, port->dev,
			      MKDEV(PP_MAJOR, port->number),
			      NULL, "parport%d", port->number);
}

static void pp_detach(struct parport *port)
{
	device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
}

static struct parport_driver pp_driver = {
	.name		= CHRDEV,
	.attach		= pp_attach,
	.detach		= pp_detach,
};

static int __init ppdev_init (void)
{
	int err = 0;

	if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
		printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
			PP_MAJOR);
		return -EIO;
	}
	ppdev_class = class_create(THIS_MODULE, CHRDEV);
	if (IS_ERR(ppdev_class)) {
		err = PTR_ERR(ppdev_class);
		goto out_chrdev;
	}
	if (parport_register_driver(&pp_driver)) {
		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
		goto out_class;
	}

	printk (KERN_INFO PP_VERSION "\n");
	goto out;

out_class:
	class_destroy(ppdev_class);
out_chrdev:
	unregister_chrdev(PP_MAJOR, CHRDEV);
out:
	return err;
}

static void __exit ppdev_cleanup (void)
{
	/* Clean up all parport stuff */
	parport_unregister_driver(&pp_driver);
	class_destroy(ppdev_class);
	unregister_chrdev (PP_MAJOR, CHRDEV);
}

module_init(ppdev_init);
module_exit(ppdev_cleanup);

MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);