xref: /linux/drivers/char/ppdev.c (revision a5c4300389bb33ade2515c082709217f0614cf15)
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/smp_lock.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;
78 	wait_queue_head_t irq_wait;
79 	atomic_t irqc;
80 	unsigned int flags;
81 	int irqresponse;
82 	unsigned char irqctl;
83 	struct ieee1284_info state;
84 	struct ieee1284_info saved_state;
85 	long default_inactivity;
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 inline void pp_enable_irq (struct pp_struct *pp)
101 {
102 	struct parport *port = pp->pdev->port;
103 	port->ops->enable_irq (port);
104 }
105 
106 static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
107 			loff_t * ppos)
108 {
109 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
110 	struct pp_struct *pp = file->private_data;
111 	char * kbuffer;
112 	ssize_t bytes_read = 0;
113 	struct parport *pport;
114 	int mode;
115 
116 	if (!(pp->flags & PP_CLAIMED)) {
117 		/* Don't have the port claimed */
118 		pr_debug(CHRDEV "%x: claim the port first\n", minor);
119 		return -EINVAL;
120 	}
121 
122 	/* Trivial case. */
123 	if (count == 0)
124 		return 0;
125 
126 	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
127 	if (!kbuffer) {
128 		return -ENOMEM;
129 	}
130 	pport = pp->pdev->port;
131 	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
132 
133 	parport_set_timeout (pp->pdev,
134 			     (file->f_flags & O_NONBLOCK) ?
135 			     PARPORT_INACTIVITY_O_NONBLOCK :
136 			     pp->default_inactivity);
137 
138 	while (bytes_read == 0) {
139 		ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
140 
141 		if (mode == IEEE1284_MODE_EPP) {
142 			/* various specials for EPP mode */
143 			int flags = 0;
144 			size_t (*fn)(struct parport *, void *, size_t, int);
145 
146 			if (pp->flags & PP_W91284PIC) {
147 				flags |= PARPORT_W91284PIC;
148 			}
149 			if (pp->flags & PP_FASTREAD) {
150 				flags |= PARPORT_EPP_FAST;
151 			}
152 			if (pport->ieee1284.mode & IEEE1284_ADDR) {
153 				fn = pport->ops->epp_read_addr;
154 			} else {
155 				fn = pport->ops->epp_read_data;
156 			}
157 			bytes_read = (*fn)(pport, kbuffer, need, flags);
158 		} else {
159 			bytes_read = parport_read (pport, kbuffer, need);
160 		}
161 
162 		if (bytes_read != 0)
163 			break;
164 
165 		if (file->f_flags & O_NONBLOCK) {
166 			bytes_read = -EAGAIN;
167 			break;
168 		}
169 
170 		if (signal_pending (current)) {
171 			bytes_read = -ERESTARTSYS;
172 			break;
173 		}
174 
175 		cond_resched();
176 	}
177 
178 	parport_set_timeout (pp->pdev, pp->default_inactivity);
179 
180 	if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
181 		bytes_read = -EFAULT;
182 
183 	kfree (kbuffer);
184 	pp_enable_irq (pp);
185 	return bytes_read;
186 }
187 
188 static ssize_t pp_write (struct file * file, const char __user * buf,
189 			 size_t count, loff_t * ppos)
190 {
191 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
192 	struct pp_struct *pp = file->private_data;
193 	char * kbuffer;
194 	ssize_t bytes_written = 0;
195 	ssize_t wrote;
196 	int mode;
197 	struct parport *pport;
198 
199 	if (!(pp->flags & PP_CLAIMED)) {
200 		/* Don't have the port claimed */
201 		pr_debug(CHRDEV "%x: claim the port first\n", minor);
202 		return -EINVAL;
203 	}
204 
205 	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
206 	if (!kbuffer) {
207 		return -ENOMEM;
208 	}
209 	pport = pp->pdev->port;
210 	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
211 
212 	parport_set_timeout (pp->pdev,
213 			     (file->f_flags & O_NONBLOCK) ?
214 			     PARPORT_INACTIVITY_O_NONBLOCK :
215 			     pp->default_inactivity);
216 
217 	while (bytes_written < count) {
218 		ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
219 
220 		if (copy_from_user (kbuffer, buf + bytes_written, n)) {
221 			bytes_written = -EFAULT;
222 			break;
223 		}
224 
225 		if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
226 			/* do a fast EPP write */
227 			if (pport->ieee1284.mode & IEEE1284_ADDR) {
228 				wrote = pport->ops->epp_write_addr (pport,
229 					kbuffer, n, PARPORT_EPP_FAST);
230 			} else {
231 				wrote = pport->ops->epp_write_data (pport,
232 					kbuffer, n, PARPORT_EPP_FAST);
233 			}
234 		} else {
235 			wrote = parport_write (pp->pdev->port, kbuffer, n);
236 		}
237 
238 		if (wrote <= 0) {
239 			if (!bytes_written) {
240 				bytes_written = wrote;
241 			}
242 			break;
243 		}
244 
245 		bytes_written += wrote;
246 
247 		if (file->f_flags & O_NONBLOCK) {
248 			if (!bytes_written)
249 				bytes_written = -EAGAIN;
250 			break;
251 		}
252 
253 		if (signal_pending (current)) {
254 			if (!bytes_written) {
255 				bytes_written = -EINTR;
256 			}
257 			break;
258 		}
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 	int fl;
289 
290 	name = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
291 	if (name == NULL)
292 		return -ENOMEM;
293 
294 	sprintf (name, CHRDEV "%x", minor);
295 
296 	port = parport_find_number (minor);
297 	if (!port) {
298 		printk (KERN_WARNING "%s: no associated port!\n", name);
299 		kfree (name);
300 		return -ENXIO;
301 	}
302 
303 	fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
304 	pdev = parport_register_device (port, name, NULL,
305 					NULL, pp_irq, fl, pp);
306 	parport_put_port (port);
307 
308 	if (!pdev) {
309 		printk (KERN_WARNING "%s: failed to register device!\n", name);
310 		kfree (name);
311 		return -ENXIO;
312 	}
313 
314 	pp->pdev = pdev;
315 	pr_debug("%s: registered pardevice\n", name);
316 	return 0;
317 }
318 
319 static enum ieee1284_phase init_phase (int mode)
320 {
321 	switch (mode & ~(IEEE1284_DEVICEID
322 			 | IEEE1284_ADDR)) {
323 	case IEEE1284_MODE_NIBBLE:
324 	case IEEE1284_MODE_BYTE:
325 		return IEEE1284_PH_REV_IDLE;
326 	}
327 	return IEEE1284_PH_FWD_IDLE;
328 }
329 
330 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
331 {
332 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
333 	struct pp_struct *pp = file->private_data;
334 	struct parport * port;
335 	void __user *argp = (void __user *)arg;
336 
337 	/* First handle the cases that don't take arguments. */
338 	switch (cmd) {
339 	case PPCLAIM:
340 	    {
341 		struct ieee1284_info *info;
342 		int ret;
343 
344 		if (pp->flags & PP_CLAIMED) {
345 			pr_debug(CHRDEV "%x: you've already got it!\n", minor);
346 			return -EINVAL;
347 		}
348 
349 		/* Deferred device registration. */
350 		if (!pp->pdev) {
351 			int err = register_device (minor, pp);
352 			if (err) {
353 				return err;
354 			}
355 		}
356 
357 		ret = parport_claim_or_block (pp->pdev);
358 		if (ret < 0)
359 			return ret;
360 
361 		pp->flags |= PP_CLAIMED;
362 
363 		/* For interrupt-reporting to work, we need to be
364 		 * informed of each interrupt. */
365 		pp_enable_irq (pp);
366 
367 		/* We may need to fix up the state machine. */
368 		info = &pp->pdev->port->ieee1284;
369 		pp->saved_state.mode = info->mode;
370 		pp->saved_state.phase = info->phase;
371 		info->mode = pp->state.mode;
372 		info->phase = pp->state.phase;
373 		pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
374 		parport_set_timeout (pp->pdev, pp->default_inactivity);
375 
376 		return 0;
377 	    }
378 	case PPEXCL:
379 		if (pp->pdev) {
380 			pr_debug(CHRDEV "%x: too late for PPEXCL; "
381 				"already registered\n", minor);
382 			if (pp->flags & PP_EXCL)
383 				/* But it's not really an error. */
384 				return 0;
385 			/* There's no chance of making the driver happy. */
386 			return -EINVAL;
387 		}
388 
389 		/* Just remember to register the device exclusively
390 		 * when we finally do the registration. */
391 		pp->flags |= PP_EXCL;
392 		return 0;
393 	case PPSETMODE:
394 	    {
395 		int mode;
396 		if (copy_from_user (&mode, argp, sizeof (mode)))
397 			return -EFAULT;
398 		/* FIXME: validate mode */
399 		pp->state.mode = mode;
400 		pp->state.phase = init_phase (mode);
401 
402 		if (pp->flags & PP_CLAIMED) {
403 			pp->pdev->port->ieee1284.mode = mode;
404 			pp->pdev->port->ieee1284.phase = pp->state.phase;
405 		}
406 
407 		return 0;
408 	    }
409 	case PPGETMODE:
410 	    {
411 		int mode;
412 
413 		if (pp->flags & PP_CLAIMED) {
414 			mode = pp->pdev->port->ieee1284.mode;
415 		} else {
416 			mode = pp->state.mode;
417 		}
418 		if (copy_to_user (argp, &mode, sizeof (mode))) {
419 			return -EFAULT;
420 		}
421 		return 0;
422 	    }
423 	case PPSETPHASE:
424 	    {
425 		int phase;
426 		if (copy_from_user (&phase, argp, sizeof (phase))) {
427 			return -EFAULT;
428 		}
429 		/* FIXME: validate phase */
430 		pp->state.phase = phase;
431 
432 		if (pp->flags & PP_CLAIMED) {
433 			pp->pdev->port->ieee1284.phase = phase;
434 		}
435 
436 		return 0;
437 	    }
438 	case PPGETPHASE:
439 	    {
440 		int phase;
441 
442 		if (pp->flags & PP_CLAIMED) {
443 			phase = pp->pdev->port->ieee1284.phase;
444 		} else {
445 			phase = pp->state.phase;
446 		}
447 		if (copy_to_user (argp, &phase, sizeof (phase))) {
448 			return -EFAULT;
449 		}
450 		return 0;
451 	    }
452 	case PPGETMODES:
453 	    {
454 		unsigned int modes;
455 
456 		port = parport_find_number (minor);
457 		if (!port)
458 			return -ENODEV;
459 
460 		modes = port->modes;
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 		par_timeout.tv_sec = to_jiffies / HZ;
618 		par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
619 		if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
620 			return -EFAULT;
621 		return 0;
622 
623 	default:
624 		pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
625 		return -EINVAL;
626 	}
627 
628 	/* Keep the compiler happy */
629 	return 0;
630 }
631 
632 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
633 {
634 	long ret;
635 	lock_kernel();
636 	ret = pp_do_ioctl(file, cmd, arg);
637 	unlock_kernel();
638 	return ret;
639 }
640 
641 static int pp_open (struct inode * inode, struct file * file)
642 {
643 	unsigned int minor = iminor(inode);
644 	struct pp_struct *pp;
645 
646 	cycle_kernel_lock();
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);
659 	init_waitqueue_head (&pp->irq_wait);
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 */
683 		parport_claim_or_block (pp->pdev);
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) {
696 		parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
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;
718 		parport_unregister_device (pp->pdev);
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 	if (parport_register_driver(&pp_driver)) {
787 		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
788 		goto out_class;
789 	}
790 
791 	printk (KERN_INFO PP_VERSION "\n");
792 	goto out;
793 
794 out_class:
795 	class_destroy(ppdev_class);
796 out_chrdev:
797 	unregister_chrdev(PP_MAJOR, CHRDEV);
798 out:
799 	return err;
800 }
801 
802 static void __exit ppdev_cleanup (void)
803 {
804 	/* Clean up all parport stuff */
805 	parport_unregister_driver(&pp_driver);
806 	class_destroy(ppdev_class);
807 	unregister_chrdev (PP_MAJOR, CHRDEV);
808 }
809 
810 module_init(ppdev_init);
811 module_exit(ppdev_cleanup);
812 
813 MODULE_LICENSE("GPL");
814 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
815