xref: /openbmc/linux/drivers/char/ppdev.c (revision 4800cd83)
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 
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 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 
134 	parport_set_timeout (pp->pdev,
135 			     (file->f_flags & O_NONBLOCK) ?
136 			     PARPORT_INACTIVITY_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 
179 	parport_set_timeout (pp->pdev, pp->default_inactivity);
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 
213 	parport_set_timeout (pp->pdev,
214 			     (file->f_flags & O_NONBLOCK) ?
215 			     PARPORT_INACTIVITY_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 
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 	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)) {
322 	case IEEE1284_MODE_NIBBLE:
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;
372 		pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
373 		parport_set_timeout (pp->pdev, pp->default_inactivity);
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 		if (copy_to_user (argp, &modes, sizeof (modes))) {
461 			return -EFAULT;
462 		}
463 		return 0;
464 	    }
465 	case PPSETFLAGS:
466 	    {
467 		int uflags;
468 
469 		if (copy_from_user (&uflags, argp, sizeof (uflags))) {
470 			return -EFAULT;
471 		}
472 		pp->flags &= ~PP_FLAGMASK;
473 		pp->flags |= (uflags & PP_FLAGMASK);
474 		return 0;
475 	    }
476 	case PPGETFLAGS:
477 	    {
478 		int uflags;
479 
480 		uflags = pp->flags & PP_FLAGMASK;
481 		if (copy_to_user (argp, &uflags, sizeof (uflags))) {
482 			return -EFAULT;
483 		}
484 		return 0;
485 	    }
486 	}	/* end switch() */
487 
488 	/* Everything else requires the port to be claimed, so check
489 	 * that now. */
490 	if ((pp->flags & PP_CLAIMED) == 0) {
491 		pr_debug(CHRDEV "%x: claim the port first\n", minor);
492 		return -EINVAL;
493 	}
494 
495 	port = pp->pdev->port;
496 	switch (cmd) {
497 		struct ieee1284_info *info;
498 		unsigned char reg;
499 		unsigned char mask;
500 		int mode;
501 		int ret;
502 		struct timeval par_timeout;
503 		long to_jiffies;
504 
505 	case PPRSTATUS:
506 		reg = parport_read_status (port);
507 		if (copy_to_user (argp, &reg, sizeof (reg)))
508 			return -EFAULT;
509 		return 0;
510 	case PPRDATA:
511 		reg = parport_read_data (port);
512 		if (copy_to_user (argp, &reg, sizeof (reg)))
513 			return -EFAULT;
514 		return 0;
515 	case PPRCONTROL:
516 		reg = parport_read_control (port);
517 		if (copy_to_user (argp, &reg, sizeof (reg)))
518 			return -EFAULT;
519 		return 0;
520 	case PPYIELD:
521 		parport_yield_blocking (pp->pdev);
522 		return 0;
523 
524 	case PPRELEASE:
525 		/* Save the state machine's state. */
526 		info = &pp->pdev->port->ieee1284;
527 		pp->state.mode = info->mode;
528 		pp->state.phase = info->phase;
529 		info->mode = pp->saved_state.mode;
530 		info->phase = pp->saved_state.phase;
531 		parport_release (pp->pdev);
532 		pp->flags &= ~PP_CLAIMED;
533 		return 0;
534 
535 	case PPWCONTROL:
536 		if (copy_from_user (&reg, argp, sizeof (reg)))
537 			return -EFAULT;
538 		parport_write_control (port, reg);
539 		return 0;
540 
541 	case PPWDATA:
542 		if (copy_from_user (&reg, argp, sizeof (reg)))
543 			return -EFAULT;
544 		parport_write_data (port, reg);
545 		return 0;
546 
547 	case PPFCONTROL:
548 		if (copy_from_user (&mask, argp,
549 				    sizeof (mask)))
550 			return -EFAULT;
551 		if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
552 				    sizeof (reg)))
553 			return -EFAULT;
554 		parport_frob_control (port, mask, reg);
555 		return 0;
556 
557 	case PPDATADIR:
558 		if (copy_from_user (&mode, argp, sizeof (mode)))
559 			return -EFAULT;
560 		if (mode)
561 			port->ops->data_reverse (port);
562 		else
563 			port->ops->data_forward (port);
564 		return 0;
565 
566 	case PPNEGOT:
567 		if (copy_from_user (&mode, argp, sizeof (mode)))
568 			return -EFAULT;
569 		switch ((ret = parport_negotiate (port, mode))) {
570 		case 0: break;
571 		case -1: /* handshake failed, peripheral not IEEE 1284 */
572 			ret = -EIO;
573 			break;
574 		case 1:  /* handshake succeeded, peripheral rejected mode */
575 			ret = -ENXIO;
576 			break;
577 		}
578 		pp_enable_irq (pp);
579 		return ret;
580 
581 	case PPWCTLONIRQ:
582 		if (copy_from_user (&reg, argp, sizeof (reg)))
583 			return -EFAULT;
584 
585 		/* Remember what to set the control lines to, for next
586 		 * time we get an interrupt. */
587 		pp->irqctl = reg;
588 		pp->irqresponse = 1;
589 		return 0;
590 
591 	case PPCLRIRQ:
592 		ret = atomic_read (&pp->irqc);
593 		if (copy_to_user (argp, &ret, sizeof (ret)))
594 			return -EFAULT;
595 		atomic_sub (ret, &pp->irqc);
596 		return 0;
597 
598 	case PPSETTIME:
599 		if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
600 			return -EFAULT;
601 		}
602 		/* Convert to jiffies, place in pp->pdev->timeout */
603 		if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
604 			return -EINVAL;
605 		}
606 		to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
607 		to_jiffies += par_timeout.tv_sec * (long)HZ;
608 		if (to_jiffies <= 0) {
609 			return -EINVAL;
610 		}
611 		pp->pdev->timeout = to_jiffies;
612 		return 0;
613 
614 	case PPGETTIME:
615 		to_jiffies = pp->pdev->timeout;
616 		memset(&par_timeout, 0, sizeof(par_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 	mutex_lock(&pp_do_mutex);
636 	ret = pp_do_ioctl(file, cmd, arg);
637 	mutex_unlock(&pp_do_mutex);
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 	if (minor >= PARPORT_MAX)
647 		return -ENXIO;
648 
649 	pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
650 	if (!pp)
651 		return -ENOMEM;
652 
653 	pp->state.mode = IEEE1284_MODE_COMPAT;
654 	pp->state.phase = init_phase (pp->state.mode);
655 	pp->flags = 0;
656 	pp->irqresponse = 0;
657 	atomic_set (&pp->irqc, 0);
658 	init_waitqueue_head (&pp->irq_wait);
659 
660 	/* Defer the actual device registration until the first claim.
661 	 * That way, we know whether or not the driver wants to have
662 	 * exclusive access to the port (PPEXCL).
663 	 */
664 	pp->pdev = NULL;
665 	file->private_data = pp;
666 
667 	return 0;
668 }
669 
670 static int pp_release (struct inode * inode, struct file * file)
671 {
672 	unsigned int minor = iminor(inode);
673 	struct pp_struct *pp = file->private_data;
674 	int compat_negot;
675 
676 	compat_negot = 0;
677 	if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
678 	    (pp->state.mode != IEEE1284_MODE_COMPAT)) {
679 	    	struct ieee1284_info *info;
680 
681 		/* parport released, but not in compatibility mode */
682 		parport_claim_or_block (pp->pdev);
683 		pp->flags |= PP_CLAIMED;
684 		info = &pp->pdev->port->ieee1284;
685 		pp->saved_state.mode = info->mode;
686 		pp->saved_state.phase = info->phase;
687 		info->mode = pp->state.mode;
688 		info->phase = pp->state.phase;
689 		compat_negot = 1;
690 	} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
691 	    (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
692 		compat_negot = 2;
693 	}
694 	if (compat_negot) {
695 		parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
696 		pr_debug(CHRDEV "%x: negotiated back to compatibility "
697 			"mode because user-space forgot\n", minor);
698 	}
699 
700 	if (pp->flags & PP_CLAIMED) {
701 		struct ieee1284_info *info;
702 
703 		info = &pp->pdev->port->ieee1284;
704 		pp->state.mode = info->mode;
705 		pp->state.phase = info->phase;
706 		info->mode = pp->saved_state.mode;
707 		info->phase = pp->saved_state.phase;
708 		parport_release (pp->pdev);
709 		if (compat_negot != 1) {
710 			pr_debug(CHRDEV "%x: released pardevice "
711 				"because user-space forgot\n", minor);
712 		}
713 	}
714 
715 	if (pp->pdev) {
716 		const char *name = pp->pdev->name;
717 		parport_unregister_device (pp->pdev);
718 		kfree (name);
719 		pp->pdev = NULL;
720 		pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
721 	}
722 
723 	kfree (pp);
724 
725 	return 0;
726 }
727 
728 /* No kernel lock held - fine */
729 static unsigned int pp_poll (struct file * file, poll_table * wait)
730 {
731 	struct pp_struct *pp = file->private_data;
732 	unsigned int mask = 0;
733 
734 	poll_wait (file, &pp->irq_wait, wait);
735 	if (atomic_read (&pp->irqc))
736 		mask |= POLLIN | POLLRDNORM;
737 
738 	return mask;
739 }
740 
741 static struct class *ppdev_class;
742 
743 static const struct file_operations pp_fops = {
744 	.owner		= THIS_MODULE,
745 	.llseek		= no_llseek,
746 	.read		= pp_read,
747 	.write		= pp_write,
748 	.poll		= pp_poll,
749 	.unlocked_ioctl	= pp_ioctl,
750 	.open		= pp_open,
751 	.release	= pp_release,
752 };
753 
754 static void pp_attach(struct parport *port)
755 {
756 	device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
757 		      NULL, "parport%d", port->number);
758 }
759 
760 static void pp_detach(struct parport *port)
761 {
762 	device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
763 }
764 
765 static struct parport_driver pp_driver = {
766 	.name		= CHRDEV,
767 	.attach		= pp_attach,
768 	.detach		= pp_detach,
769 };
770 
771 static int __init ppdev_init (void)
772 {
773 	int err = 0;
774 
775 	if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
776 		printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
777 			PP_MAJOR);
778 		return -EIO;
779 	}
780 	ppdev_class = class_create(THIS_MODULE, CHRDEV);
781 	if (IS_ERR(ppdev_class)) {
782 		err = PTR_ERR(ppdev_class);
783 		goto out_chrdev;
784 	}
785 	if (parport_register_driver(&pp_driver)) {
786 		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
787 		goto out_class;
788 	}
789 
790 	printk (KERN_INFO PP_VERSION "\n");
791 	goto out;
792 
793 out_class:
794 	class_destroy(ppdev_class);
795 out_chrdev:
796 	unregister_chrdev(PP_MAJOR, CHRDEV);
797 out:
798 	return err;
799 }
800 
801 static void __exit ppdev_cleanup (void)
802 {
803 	/* Clean up all parport stuff */
804 	parport_unregister_driver(&pp_driver);
805 	class_destroy(ppdev_class);
806 	unregister_chrdev (PP_MAJOR, CHRDEV);
807 }
808 
809 module_init(ppdev_init);
810 module_exit(ppdev_cleanup);
811 
812 MODULE_LICENSE("GPL");
813 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
814