xref: /openbmc/linux/drivers/char/ppdev.c (revision a1e58bbd)
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/major.h>
68 #include <linux/ppdev.h>
69 #include <asm/uaccess.h>
70 
71 #define PP_VERSION "ppdev: user-space parallel port driver"
72 #define CHRDEV "ppdev"
73 
74 struct pp_struct {
75 	struct pardevice * pdev;
76 	wait_queue_head_t irq_wait;
77 	atomic_t irqc;
78 	unsigned int flags;
79 	int irqresponse;
80 	unsigned char irqctl;
81 	struct ieee1284_info state;
82 	struct ieee1284_info saved_state;
83 	long default_inactivity;
84 };
85 
86 /* pp_struct.flags bitfields */
87 #define PP_CLAIMED    (1<<0)
88 #define PP_EXCL       (1<<1)
89 
90 /* Other constants */
91 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
92 #define PP_BUFFER_SIZE 1024
93 #define PARDEVICE_MAX 8
94 
95 /* ROUND_UP macro from fs/select.c */
96 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
97 
98 static inline void pp_enable_irq (struct pp_struct *pp)
99 {
100 	struct parport *port = pp->pdev->port;
101 	port->ops->enable_irq (port);
102 }
103 
104 static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
105 			loff_t * ppos)
106 {
107 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
108 	struct pp_struct *pp = file->private_data;
109 	char * kbuffer;
110 	ssize_t bytes_read = 0;
111 	struct parport *pport;
112 	int mode;
113 
114 	if (!(pp->flags & PP_CLAIMED)) {
115 		/* Don't have the port claimed */
116 		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
117 			minor);
118 		return -EINVAL;
119 	}
120 
121 	/* Trivial case. */
122 	if (count == 0)
123 		return 0;
124 
125 	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
126 	if (!kbuffer) {
127 		return -ENOMEM;
128 	}
129 	pport = pp->pdev->port;
130 	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
131 
132 	parport_set_timeout (pp->pdev,
133 			     (file->f_flags & O_NONBLOCK) ?
134 			     PARPORT_INACTIVITY_O_NONBLOCK :
135 			     pp->default_inactivity);
136 
137 	while (bytes_read == 0) {
138 		ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
139 
140 		if (mode == IEEE1284_MODE_EPP) {
141 			/* various specials for EPP mode */
142 			int flags = 0;
143 			size_t (*fn)(struct parport *, void *, size_t, int);
144 
145 			if (pp->flags & PP_W91284PIC) {
146 				flags |= PARPORT_W91284PIC;
147 			}
148 			if (pp->flags & PP_FASTREAD) {
149 				flags |= PARPORT_EPP_FAST;
150 			}
151 			if (pport->ieee1284.mode & IEEE1284_ADDR) {
152 				fn = pport->ops->epp_read_addr;
153 			} else {
154 				fn = pport->ops->epp_read_data;
155 			}
156 			bytes_read = (*fn)(pport, kbuffer, need, flags);
157 		} else {
158 			bytes_read = parport_read (pport, kbuffer, need);
159 		}
160 
161 		if (bytes_read != 0)
162 			break;
163 
164 		if (file->f_flags & O_NONBLOCK) {
165 			bytes_read = -EAGAIN;
166 			break;
167 		}
168 
169 		if (signal_pending (current)) {
170 			bytes_read = -ERESTARTSYS;
171 			break;
172 		}
173 
174 		cond_resched();
175 	}
176 
177 	parport_set_timeout (pp->pdev, pp->default_inactivity);
178 
179 	if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
180 		bytes_read = -EFAULT;
181 
182 	kfree (kbuffer);
183 	pp_enable_irq (pp);
184 	return bytes_read;
185 }
186 
187 static ssize_t pp_write (struct file * file, const char __user * buf,
188 			 size_t count, loff_t * ppos)
189 {
190 	unsigned int minor = iminor(file->f_path.dentry->d_inode);
191 	struct pp_struct *pp = file->private_data;
192 	char * kbuffer;
193 	ssize_t bytes_written = 0;
194 	ssize_t wrote;
195 	int mode;
196 	struct parport *pport;
197 
198 	if (!(pp->flags & PP_CLAIMED)) {
199 		/* Don't have the port claimed */
200 		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
201 			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 	printk (KERN_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_ioctl(struct inode *inode, struct file *file,
331 		    unsigned int cmd, unsigned long arg)
332 {
333 	unsigned int minor = iminor(inode);
334 	struct pp_struct *pp = file->private_data;
335 	struct parport * port;
336 	void __user *argp = (void __user *)arg;
337 
338 	/* First handle the cases that don't take arguments. */
339 	switch (cmd) {
340 	case PPCLAIM:
341 	    {
342 		struct ieee1284_info *info;
343 		int ret;
344 
345 		if (pp->flags & PP_CLAIMED) {
346 			printk (KERN_DEBUG CHRDEV
347 				"%x: you've already got it!\n", minor);
348 			return -EINVAL;
349 		}
350 
351 		/* Deferred device registration. */
352 		if (!pp->pdev) {
353 			int err = register_device (minor, pp);
354 			if (err) {
355 				return err;
356 			}
357 		}
358 
359 		ret = parport_claim_or_block (pp->pdev);
360 		if (ret < 0)
361 			return ret;
362 
363 		pp->flags |= PP_CLAIMED;
364 
365 		/* For interrupt-reporting to work, we need to be
366 		 * informed of each interrupt. */
367 		pp_enable_irq (pp);
368 
369 		/* We may need to fix up the state machine. */
370 		info = &pp->pdev->port->ieee1284;
371 		pp->saved_state.mode = info->mode;
372 		pp->saved_state.phase = info->phase;
373 		info->mode = pp->state.mode;
374 		info->phase = pp->state.phase;
375 		pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
376 		parport_set_timeout (pp->pdev, pp->default_inactivity);
377 
378 		return 0;
379 	    }
380 	case PPEXCL:
381 		if (pp->pdev) {
382 			printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
383 				"already registered\n", minor);
384 			if (pp->flags & PP_EXCL)
385 				/* But it's not really an error. */
386 				return 0;
387 			/* There's no chance of making the driver happy. */
388 			return -EINVAL;
389 		}
390 
391 		/* Just remember to register the device exclusively
392 		 * when we finally do the registration. */
393 		pp->flags |= PP_EXCL;
394 		return 0;
395 	case PPSETMODE:
396 	    {
397 		int mode;
398 		if (copy_from_user (&mode, argp, sizeof (mode)))
399 			return -EFAULT;
400 		/* FIXME: validate mode */
401 		pp->state.mode = mode;
402 		pp->state.phase = init_phase (mode);
403 
404 		if (pp->flags & PP_CLAIMED) {
405 			pp->pdev->port->ieee1284.mode = mode;
406 			pp->pdev->port->ieee1284.phase = pp->state.phase;
407 		}
408 
409 		return 0;
410 	    }
411 	case PPGETMODE:
412 	    {
413 		int mode;
414 
415 		if (pp->flags & PP_CLAIMED) {
416 			mode = pp->pdev->port->ieee1284.mode;
417 		} else {
418 			mode = pp->state.mode;
419 		}
420 		if (copy_to_user (argp, &mode, sizeof (mode))) {
421 			return -EFAULT;
422 		}
423 		return 0;
424 	    }
425 	case PPSETPHASE:
426 	    {
427 		int phase;
428 		if (copy_from_user (&phase, argp, sizeof (phase))) {
429 			return -EFAULT;
430 		}
431 		/* FIXME: validate phase */
432 		pp->state.phase = phase;
433 
434 		if (pp->flags & PP_CLAIMED) {
435 			pp->pdev->port->ieee1284.phase = phase;
436 		}
437 
438 		return 0;
439 	    }
440 	case PPGETPHASE:
441 	    {
442 		int phase;
443 
444 		if (pp->flags & PP_CLAIMED) {
445 			phase = pp->pdev->port->ieee1284.phase;
446 		} else {
447 			phase = pp->state.phase;
448 		}
449 		if (copy_to_user (argp, &phase, sizeof (phase))) {
450 			return -EFAULT;
451 		}
452 		return 0;
453 	    }
454 	case PPGETMODES:
455 	    {
456 		unsigned int modes;
457 
458 		port = parport_find_number (minor);
459 		if (!port)
460 			return -ENODEV;
461 
462 		modes = port->modes;
463 		if (copy_to_user (argp, &modes, sizeof (modes))) {
464 			return -EFAULT;
465 		}
466 		return 0;
467 	    }
468 	case PPSETFLAGS:
469 	    {
470 		int uflags;
471 
472 		if (copy_from_user (&uflags, argp, sizeof (uflags))) {
473 			return -EFAULT;
474 		}
475 		pp->flags &= ~PP_FLAGMASK;
476 		pp->flags |= (uflags & PP_FLAGMASK);
477 		return 0;
478 	    }
479 	case PPGETFLAGS:
480 	    {
481 		int uflags;
482 
483 		uflags = pp->flags & PP_FLAGMASK;
484 		if (copy_to_user (argp, &uflags, sizeof (uflags))) {
485 			return -EFAULT;
486 		}
487 		return 0;
488 	    }
489 	}	/* end switch() */
490 
491 	/* Everything else requires the port to be claimed, so check
492 	 * that now. */
493 	if ((pp->flags & PP_CLAIMED) == 0) {
494 		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
495 			minor);
496 		return -EINVAL;
497 	}
498 
499 	port = pp->pdev->port;
500 	switch (cmd) {
501 		struct ieee1284_info *info;
502 		unsigned char reg;
503 		unsigned char mask;
504 		int mode;
505 		int ret;
506 		struct timeval par_timeout;
507 		long to_jiffies;
508 
509 	case PPRSTATUS:
510 		reg = parport_read_status (port);
511 		if (copy_to_user (argp, &reg, sizeof (reg)))
512 			return -EFAULT;
513 		return 0;
514 	case PPRDATA:
515 		reg = parport_read_data (port);
516 		if (copy_to_user (argp, &reg, sizeof (reg)))
517 			return -EFAULT;
518 		return 0;
519 	case PPRCONTROL:
520 		reg = parport_read_control (port);
521 		if (copy_to_user (argp, &reg, sizeof (reg)))
522 			return -EFAULT;
523 		return 0;
524 	case PPYIELD:
525 		parport_yield_blocking (pp->pdev);
526 		return 0;
527 
528 	case PPRELEASE:
529 		/* Save the state machine's state. */
530 		info = &pp->pdev->port->ieee1284;
531 		pp->state.mode = info->mode;
532 		pp->state.phase = info->phase;
533 		info->mode = pp->saved_state.mode;
534 		info->phase = pp->saved_state.phase;
535 		parport_release (pp->pdev);
536 		pp->flags &= ~PP_CLAIMED;
537 		return 0;
538 
539 	case PPWCONTROL:
540 		if (copy_from_user (&reg, argp, sizeof (reg)))
541 			return -EFAULT;
542 		parport_write_control (port, reg);
543 		return 0;
544 
545 	case PPWDATA:
546 		if (copy_from_user (&reg, argp, sizeof (reg)))
547 			return -EFAULT;
548 		parport_write_data (port, reg);
549 		return 0;
550 
551 	case PPFCONTROL:
552 		if (copy_from_user (&mask, argp,
553 				    sizeof (mask)))
554 			return -EFAULT;
555 		if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
556 				    sizeof (reg)))
557 			return -EFAULT;
558 		parport_frob_control (port, mask, reg);
559 		return 0;
560 
561 	case PPDATADIR:
562 		if (copy_from_user (&mode, argp, sizeof (mode)))
563 			return -EFAULT;
564 		if (mode)
565 			port->ops->data_reverse (port);
566 		else
567 			port->ops->data_forward (port);
568 		return 0;
569 
570 	case PPNEGOT:
571 		if (copy_from_user (&mode, argp, sizeof (mode)))
572 			return -EFAULT;
573 		switch ((ret = parport_negotiate (port, mode))) {
574 		case 0: break;
575 		case -1: /* handshake failed, peripheral not IEEE 1284 */
576 			ret = -EIO;
577 			break;
578 		case 1:  /* handshake succeeded, peripheral rejected mode */
579 			ret = -ENXIO;
580 			break;
581 		}
582 		pp_enable_irq (pp);
583 		return ret;
584 
585 	case PPWCTLONIRQ:
586 		if (copy_from_user (&reg, argp, sizeof (reg)))
587 			return -EFAULT;
588 
589 		/* Remember what to set the control lines to, for next
590 		 * time we get an interrupt. */
591 		pp->irqctl = reg;
592 		pp->irqresponse = 1;
593 		return 0;
594 
595 	case PPCLRIRQ:
596 		ret = atomic_read (&pp->irqc);
597 		if (copy_to_user (argp, &ret, sizeof (ret)))
598 			return -EFAULT;
599 		atomic_sub (ret, &pp->irqc);
600 		return 0;
601 
602 	case PPSETTIME:
603 		if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
604 			return -EFAULT;
605 		}
606 		/* Convert to jiffies, place in pp->pdev->timeout */
607 		if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
608 			return -EINVAL;
609 		}
610 		to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
611 		to_jiffies += par_timeout.tv_sec * (long)HZ;
612 		if (to_jiffies <= 0) {
613 			return -EINVAL;
614 		}
615 		pp->pdev->timeout = to_jiffies;
616 		return 0;
617 
618 	case PPGETTIME:
619 		to_jiffies = pp->pdev->timeout;
620 		par_timeout.tv_sec = to_jiffies / HZ;
621 		par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
622 		if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
623 			return -EFAULT;
624 		return 0;
625 
626 	default:
627 		printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
628 			cmd);
629 		return -EINVAL;
630 	}
631 
632 	/* Keep the compiler happy */
633 	return 0;
634 }
635 
636 static int pp_open (struct inode * inode, struct file * file)
637 {
638 	unsigned int minor = iminor(inode);
639 	struct pp_struct *pp;
640 
641 	if (minor >= PARPORT_MAX)
642 		return -ENXIO;
643 
644 	pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
645 	if (!pp)
646 		return -ENOMEM;
647 
648 	pp->state.mode = IEEE1284_MODE_COMPAT;
649 	pp->state.phase = init_phase (pp->state.mode);
650 	pp->flags = 0;
651 	pp->irqresponse = 0;
652 	atomic_set (&pp->irqc, 0);
653 	init_waitqueue_head (&pp->irq_wait);
654 
655 	/* Defer the actual device registration until the first claim.
656 	 * That way, we know whether or not the driver wants to have
657 	 * exclusive access to the port (PPEXCL).
658 	 */
659 	pp->pdev = NULL;
660 	file->private_data = pp;
661 
662 	return 0;
663 }
664 
665 static int pp_release (struct inode * inode, struct file * file)
666 {
667 	unsigned int minor = iminor(inode);
668 	struct pp_struct *pp = file->private_data;
669 	int compat_negot;
670 
671 	compat_negot = 0;
672 	if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
673 	    (pp->state.mode != IEEE1284_MODE_COMPAT)) {
674 	    	struct ieee1284_info *info;
675 
676 		/* parport released, but not in compatibility mode */
677 		parport_claim_or_block (pp->pdev);
678 		pp->flags |= PP_CLAIMED;
679 		info = &pp->pdev->port->ieee1284;
680 		pp->saved_state.mode = info->mode;
681 		pp->saved_state.phase = info->phase;
682 		info->mode = pp->state.mode;
683 		info->phase = pp->state.phase;
684 		compat_negot = 1;
685 	} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
686 	    (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
687 		compat_negot = 2;
688 	}
689 	if (compat_negot) {
690 		parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
691 		printk (KERN_DEBUG CHRDEV
692 			"%x: negotiated back to compatibility mode because "
693 			"user-space forgot\n", minor);
694 	}
695 
696 	if (pp->flags & PP_CLAIMED) {
697 		struct ieee1284_info *info;
698 
699 		info = &pp->pdev->port->ieee1284;
700 		pp->state.mode = info->mode;
701 		pp->state.phase = info->phase;
702 		info->mode = pp->saved_state.mode;
703 		info->phase = pp->saved_state.phase;
704 		parport_release (pp->pdev);
705 		if (compat_negot != 1) {
706 			printk (KERN_DEBUG CHRDEV "%x: released pardevice "
707 				"because user-space forgot\n", minor);
708 		}
709 	}
710 
711 	if (pp->pdev) {
712 		const char *name = pp->pdev->name;
713 		parport_unregister_device (pp->pdev);
714 		kfree (name);
715 		pp->pdev = NULL;
716 		printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
717 			minor);
718 	}
719 
720 	kfree (pp);
721 
722 	return 0;
723 }
724 
725 /* No kernel lock held - fine */
726 static unsigned int pp_poll (struct file * file, poll_table * wait)
727 {
728 	struct pp_struct *pp = file->private_data;
729 	unsigned int mask = 0;
730 
731 	poll_wait (file, &pp->irq_wait, wait);
732 	if (atomic_read (&pp->irqc))
733 		mask |= POLLIN | POLLRDNORM;
734 
735 	return mask;
736 }
737 
738 static struct class *ppdev_class;
739 
740 static const struct file_operations pp_fops = {
741 	.owner		= THIS_MODULE,
742 	.llseek		= no_llseek,
743 	.read		= pp_read,
744 	.write		= pp_write,
745 	.poll		= pp_poll,
746 	.ioctl		= pp_ioctl,
747 	.open		= pp_open,
748 	.release	= pp_release,
749 };
750 
751 static void pp_attach(struct parport *port)
752 {
753 	device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
754 			"parport%d", port->number);
755 }
756 
757 static void pp_detach(struct parport *port)
758 {
759 	device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
760 }
761 
762 static struct parport_driver pp_driver = {
763 	.name		= CHRDEV,
764 	.attach		= pp_attach,
765 	.detach		= pp_detach,
766 };
767 
768 static int __init ppdev_init (void)
769 {
770 	int err = 0;
771 
772 	if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
773 		printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
774 			PP_MAJOR);
775 		return -EIO;
776 	}
777 	ppdev_class = class_create(THIS_MODULE, CHRDEV);
778 	if (IS_ERR(ppdev_class)) {
779 		err = PTR_ERR(ppdev_class);
780 		goto out_chrdev;
781 	}
782 	if (parport_register_driver(&pp_driver)) {
783 		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
784 		goto out_class;
785 	}
786 
787 	printk (KERN_INFO PP_VERSION "\n");
788 	goto out;
789 
790 out_class:
791 	class_destroy(ppdev_class);
792 out_chrdev:
793 	unregister_chrdev(PP_MAJOR, CHRDEV);
794 out:
795 	return err;
796 }
797 
798 static void __exit ppdev_cleanup (void)
799 {
800 	/* Clean up all parport stuff */
801 	parport_unregister_driver(&pp_driver);
802 	class_destroy(ppdev_class);
803 	unregister_chrdev (PP_MAJOR, CHRDEV);
804 }
805 
806 module_init(ppdev_init);
807 module_exit(ppdev_cleanup);
808 
809 MODULE_LICENSE("GPL");
810 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
811