xref: /linux/drivers/char/ppdev.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
291 	if (name == NULL)
292 		return -ENOMEM;
293 
294 	port = parport_find_number (minor);
295 	if (!port) {
296 		printk (KERN_WARNING "%s: no associated port!\n", name);
297 		kfree (name);
298 		return -ENXIO;
299 	}
300 
301 	fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
302 	pdev = parport_register_device (port, name, NULL,
303 					NULL, pp_irq, fl, pp);
304 	parport_put_port (port);
305 
306 	if (!pdev) {
307 		printk (KERN_WARNING "%s: failed to register device!\n", name);
308 		kfree (name);
309 		return -ENXIO;
310 	}
311 
312 	pp->pdev = pdev;
313 	pr_debug("%s: registered pardevice\n", name);
314 	return 0;
315 }
316 
317 static enum ieee1284_phase init_phase (int mode)
318 {
319 	switch (mode & ~(IEEE1284_DEVICEID
320 			 | IEEE1284_ADDR)) {
321 	case IEEE1284_MODE_NIBBLE:
322 	case IEEE1284_MODE_BYTE:
323 		return IEEE1284_PH_REV_IDLE;
324 	}
325 	return IEEE1284_PH_FWD_IDLE;
326 }
327 
328 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
329 {
330 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
331 	struct pp_struct *pp = file->private_data;
332 	struct parport * port;
333 	void __user *argp = (void __user *)arg;
334 
335 	/* First handle the cases that don't take arguments. */
336 	switch (cmd) {
337 	case PPCLAIM:
338 	    {
339 		struct ieee1284_info *info;
340 		int ret;
341 
342 		if (pp->flags & PP_CLAIMED) {
343 			pr_debug(CHRDEV "%x: you've already got it!\n", minor);
344 			return -EINVAL;
345 		}
346 
347 		/* Deferred device registration. */
348 		if (!pp->pdev) {
349 			int err = register_device (minor, pp);
350 			if (err) {
351 				return err;
352 			}
353 		}
354 
355 		ret = parport_claim_or_block (pp->pdev);
356 		if (ret < 0)
357 			return ret;
358 
359 		pp->flags |= PP_CLAIMED;
360 
361 		/* For interrupt-reporting to work, we need to be
362 		 * informed of each interrupt. */
363 		pp_enable_irq (pp);
364 
365 		/* We may need to fix up the state machine. */
366 		info = &pp->pdev->port->ieee1284;
367 		pp->saved_state.mode = info->mode;
368 		pp->saved_state.phase = info->phase;
369 		info->mode = pp->state.mode;
370 		info->phase = pp->state.phase;
371 		pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
372 		parport_set_timeout (pp->pdev, pp->default_inactivity);
373 
374 		return 0;
375 	    }
376 	case PPEXCL:
377 		if (pp->pdev) {
378 			pr_debug(CHRDEV "%x: too late for PPEXCL; "
379 				"already registered\n", minor);
380 			if (pp->flags & PP_EXCL)
381 				/* But it's not really an error. */
382 				return 0;
383 			/* There's no chance of making the driver happy. */
384 			return -EINVAL;
385 		}
386 
387 		/* Just remember to register the device exclusively
388 		 * when we finally do the registration. */
389 		pp->flags |= PP_EXCL;
390 		return 0;
391 	case PPSETMODE:
392 	    {
393 		int mode;
394 		if (copy_from_user (&mode, argp, sizeof (mode)))
395 			return -EFAULT;
396 		/* FIXME: validate mode */
397 		pp->state.mode = mode;
398 		pp->state.phase = init_phase (mode);
399 
400 		if (pp->flags & PP_CLAIMED) {
401 			pp->pdev->port->ieee1284.mode = mode;
402 			pp->pdev->port->ieee1284.phase = pp->state.phase;
403 		}
404 
405 		return 0;
406 	    }
407 	case PPGETMODE:
408 	    {
409 		int mode;
410 
411 		if (pp->flags & PP_CLAIMED) {
412 			mode = pp->pdev->port->ieee1284.mode;
413 		} else {
414 			mode = pp->state.mode;
415 		}
416 		if (copy_to_user (argp, &mode, sizeof (mode))) {
417 			return -EFAULT;
418 		}
419 		return 0;
420 	    }
421 	case PPSETPHASE:
422 	    {
423 		int phase;
424 		if (copy_from_user (&phase, argp, sizeof (phase))) {
425 			return -EFAULT;
426 		}
427 		/* FIXME: validate phase */
428 		pp->state.phase = phase;
429 
430 		if (pp->flags & PP_CLAIMED) {
431 			pp->pdev->port->ieee1284.phase = phase;
432 		}
433 
434 		return 0;
435 	    }
436 	case PPGETPHASE:
437 	    {
438 		int phase;
439 
440 		if (pp->flags & PP_CLAIMED) {
441 			phase = pp->pdev->port->ieee1284.phase;
442 		} else {
443 			phase = pp->state.phase;
444 		}
445 		if (copy_to_user (argp, &phase, sizeof (phase))) {
446 			return -EFAULT;
447 		}
448 		return 0;
449 	    }
450 	case PPGETMODES:
451 	    {
452 		unsigned int modes;
453 
454 		port = parport_find_number (minor);
455 		if (!port)
456 			return -ENODEV;
457 
458 		modes = port->modes;
459 		if (copy_to_user (argp, &modes, sizeof (modes))) {
460 			return -EFAULT;
461 		}
462 		return 0;
463 	    }
464 	case PPSETFLAGS:
465 	    {
466 		int uflags;
467 
468 		if (copy_from_user (&uflags, argp, sizeof (uflags))) {
469 			return -EFAULT;
470 		}
471 		pp->flags &= ~PP_FLAGMASK;
472 		pp->flags |= (uflags & PP_FLAGMASK);
473 		return 0;
474 	    }
475 	case PPGETFLAGS:
476 	    {
477 		int uflags;
478 
479 		uflags = pp->flags & PP_FLAGMASK;
480 		if (copy_to_user (argp, &uflags, sizeof (uflags))) {
481 			return -EFAULT;
482 		}
483 		return 0;
484 	    }
485 	}	/* end switch() */
486 
487 	/* Everything else requires the port to be claimed, so check
488 	 * that now. */
489 	if ((pp->flags & PP_CLAIMED) == 0) {
490 		pr_debug(CHRDEV "%x: claim the port first\n", minor);
491 		return -EINVAL;
492 	}
493 
494 	port = pp->pdev->port;
495 	switch (cmd) {
496 		struct ieee1284_info *info;
497 		unsigned char reg;
498 		unsigned char mask;
499 		int mode;
500 		int ret;
501 		struct timeval par_timeout;
502 		long to_jiffies;
503 
504 	case PPRSTATUS:
505 		reg = parport_read_status (port);
506 		if (copy_to_user (argp, &reg, sizeof (reg)))
507 			return -EFAULT;
508 		return 0;
509 	case PPRDATA:
510 		reg = parport_read_data (port);
511 		if (copy_to_user (argp, &reg, sizeof (reg)))
512 			return -EFAULT;
513 		return 0;
514 	case PPRCONTROL:
515 		reg = parport_read_control (port);
516 		if (copy_to_user (argp, &reg, sizeof (reg)))
517 			return -EFAULT;
518 		return 0;
519 	case PPYIELD:
520 		parport_yield_blocking (pp->pdev);
521 		return 0;
522 
523 	case PPRELEASE:
524 		/* Save the state machine's state. */
525 		info = &pp->pdev->port->ieee1284;
526 		pp->state.mode = info->mode;
527 		pp->state.phase = info->phase;
528 		info->mode = pp->saved_state.mode;
529 		info->phase = pp->saved_state.phase;
530 		parport_release (pp->pdev);
531 		pp->flags &= ~PP_CLAIMED;
532 		return 0;
533 
534 	case PPWCONTROL:
535 		if (copy_from_user (&reg, argp, sizeof (reg)))
536 			return -EFAULT;
537 		parport_write_control (port, reg);
538 		return 0;
539 
540 	case PPWDATA:
541 		if (copy_from_user (&reg, argp, sizeof (reg)))
542 			return -EFAULT;
543 		parport_write_data (port, reg);
544 		return 0;
545 
546 	case PPFCONTROL:
547 		if (copy_from_user (&mask, argp,
548 				    sizeof (mask)))
549 			return -EFAULT;
550 		if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
551 				    sizeof (reg)))
552 			return -EFAULT;
553 		parport_frob_control (port, mask, reg);
554 		return 0;
555 
556 	case PPDATADIR:
557 		if (copy_from_user (&mode, argp, sizeof (mode)))
558 			return -EFAULT;
559 		if (mode)
560 			port->ops->data_reverse (port);
561 		else
562 			port->ops->data_forward (port);
563 		return 0;
564 
565 	case PPNEGOT:
566 		if (copy_from_user (&mode, argp, sizeof (mode)))
567 			return -EFAULT;
568 		switch ((ret = parport_negotiate (port, mode))) {
569 		case 0: break;
570 		case -1: /* handshake failed, peripheral not IEEE 1284 */
571 			ret = -EIO;
572 			break;
573 		case 1:  /* handshake succeeded, peripheral rejected mode */
574 			ret = -ENXIO;
575 			break;
576 		}
577 		pp_enable_irq (pp);
578 		return ret;
579 
580 	case PPWCTLONIRQ:
581 		if (copy_from_user (&reg, argp, sizeof (reg)))
582 			return -EFAULT;
583 
584 		/* Remember what to set the control lines to, for next
585 		 * time we get an interrupt. */
586 		pp->irqctl = reg;
587 		pp->irqresponse = 1;
588 		return 0;
589 
590 	case PPCLRIRQ:
591 		ret = atomic_read (&pp->irqc);
592 		if (copy_to_user (argp, &ret, sizeof (ret)))
593 			return -EFAULT;
594 		atomic_sub (ret, &pp->irqc);
595 		return 0;
596 
597 	case PPSETTIME:
598 		if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
599 			return -EFAULT;
600 		}
601 		/* Convert to jiffies, place in pp->pdev->timeout */
602 		if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
603 			return -EINVAL;
604 		}
605 		to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
606 		to_jiffies += par_timeout.tv_sec * (long)HZ;
607 		if (to_jiffies <= 0) {
608 			return -EINVAL;
609 		}
610 		pp->pdev->timeout = to_jiffies;
611 		return 0;
612 
613 	case PPGETTIME:
614 		to_jiffies = pp->pdev->timeout;
615 		par_timeout.tv_sec = to_jiffies / HZ;
616 		par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
617 		if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
618 			return -EFAULT;
619 		return 0;
620 
621 	default:
622 		pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
623 		return -EINVAL;
624 	}
625 
626 	/* Keep the compiler happy */
627 	return 0;
628 }
629 
630 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
631 {
632 	long ret;
633 	lock_kernel();
634 	ret = pp_do_ioctl(file, cmd, arg);
635 	unlock_kernel();
636 	return ret;
637 }
638 
639 static int pp_open (struct inode * inode, struct file * file)
640 {
641 	unsigned int minor = iminor(inode);
642 	struct pp_struct *pp;
643 
644 	cycle_kernel_lock();
645 	if (minor >= PARPORT_MAX)
646 		return -ENXIO;
647 
648 	pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
649 	if (!pp)
650 		return -ENOMEM;
651 
652 	pp->state.mode = IEEE1284_MODE_COMPAT;
653 	pp->state.phase = init_phase (pp->state.mode);
654 	pp->flags = 0;
655 	pp->irqresponse = 0;
656 	atomic_set (&pp->irqc, 0);
657 	init_waitqueue_head (&pp->irq_wait);
658 
659 	/* Defer the actual device registration until the first claim.
660 	 * That way, we know whether or not the driver wants to have
661 	 * exclusive access to the port (PPEXCL).
662 	 */
663 	pp->pdev = NULL;
664 	file->private_data = pp;
665 
666 	return 0;
667 }
668 
669 static int pp_release (struct inode * inode, struct file * file)
670 {
671 	unsigned int minor = iminor(inode);
672 	struct pp_struct *pp = file->private_data;
673 	int compat_negot;
674 
675 	compat_negot = 0;
676 	if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
677 	    (pp->state.mode != IEEE1284_MODE_COMPAT)) {
678 	    	struct ieee1284_info *info;
679 
680 		/* parport released, but not in compatibility mode */
681 		parport_claim_or_block (pp->pdev);
682 		pp->flags |= PP_CLAIMED;
683 		info = &pp->pdev->port->ieee1284;
684 		pp->saved_state.mode = info->mode;
685 		pp->saved_state.phase = info->phase;
686 		info->mode = pp->state.mode;
687 		info->phase = pp->state.phase;
688 		compat_negot = 1;
689 	} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
690 	    (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
691 		compat_negot = 2;
692 	}
693 	if (compat_negot) {
694 		parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
695 		pr_debug(CHRDEV "%x: negotiated back to compatibility "
696 			"mode because user-space forgot\n", minor);
697 	}
698 
699 	if (pp->flags & PP_CLAIMED) {
700 		struct ieee1284_info *info;
701 
702 		info = &pp->pdev->port->ieee1284;
703 		pp->state.mode = info->mode;
704 		pp->state.phase = info->phase;
705 		info->mode = pp->saved_state.mode;
706 		info->phase = pp->saved_state.phase;
707 		parport_release (pp->pdev);
708 		if (compat_negot != 1) {
709 			pr_debug(CHRDEV "%x: released pardevice "
710 				"because user-space forgot\n", minor);
711 		}
712 	}
713 
714 	if (pp->pdev) {
715 		const char *name = pp->pdev->name;
716 		parport_unregister_device (pp->pdev);
717 		kfree (name);
718 		pp->pdev = NULL;
719 		pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
720 	}
721 
722 	kfree (pp);
723 
724 	return 0;
725 }
726 
727 /* No kernel lock held - fine */
728 static unsigned int pp_poll (struct file * file, poll_table * wait)
729 {
730 	struct pp_struct *pp = file->private_data;
731 	unsigned int mask = 0;
732 
733 	poll_wait (file, &pp->irq_wait, wait);
734 	if (atomic_read (&pp->irqc))
735 		mask |= POLLIN | POLLRDNORM;
736 
737 	return mask;
738 }
739 
740 static struct class *ppdev_class;
741 
742 static const struct file_operations pp_fops = {
743 	.owner		= THIS_MODULE,
744 	.llseek		= no_llseek,
745 	.read		= pp_read,
746 	.write		= pp_write,
747 	.poll		= pp_poll,
748 	.unlocked_ioctl	= pp_ioctl,
749 	.open		= pp_open,
750 	.release	= pp_release,
751 };
752 
753 static void pp_attach(struct parport *port)
754 {
755 	device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
756 		      NULL, "parport%d", port->number);
757 }
758 
759 static void pp_detach(struct parport *port)
760 {
761 	device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
762 }
763 
764 static struct parport_driver pp_driver = {
765 	.name		= CHRDEV,
766 	.attach		= pp_attach,
767 	.detach		= pp_detach,
768 };
769 
770 static int __init ppdev_init (void)
771 {
772 	int err = 0;
773 
774 	if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
775 		printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
776 			PP_MAJOR);
777 		return -EIO;
778 	}
779 	ppdev_class = class_create(THIS_MODULE, CHRDEV);
780 	if (IS_ERR(ppdev_class)) {
781 		err = PTR_ERR(ppdev_class);
782 		goto out_chrdev;
783 	}
784 	if (parport_register_driver(&pp_driver)) {
785 		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
786 		goto out_class;
787 	}
788 
789 	printk (KERN_INFO PP_VERSION "\n");
790 	goto out;
791 
792 out_class:
793 	class_destroy(ppdev_class);
794 out_chrdev:
795 	unregister_chrdev(PP_MAJOR, CHRDEV);
796 out:
797 	return err;
798 }
799 
800 static void __exit ppdev_cleanup (void)
801 {
802 	/* Clean up all parport stuff */
803 	parport_unregister_driver(&pp_driver);
804 	class_destroy(ppdev_class);
805 	unregister_chrdev (PP_MAJOR, CHRDEV);
806 }
807 
808 module_init(ppdev_init);
809 module_exit(ppdev_cleanup);
810 
811 MODULE_LICENSE("GPL");
812 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
813