xref: /openbmc/linux/drivers/char/ppdev.c (revision 87c2ce3b)
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/devfs_fs_kernel.h>
64 #include <linux/ioctl.h>
65 #include <linux/parport.h>
66 #include <linux/ctype.h>
67 #include <linux/poll.h>
68 #include <asm/uaccess.h>
69 #include <linux/ppdev.h>
70 #include <linux/smp_lock.h>
71 #include <linux/device.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_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 		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
119 			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_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 		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
203 			minor);
204 		return -EINVAL;
205 	}
206 
207 	kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
208 	if (!kbuffer) {
209 		return -ENOMEM;
210 	}
211 	pport = pp->pdev->port;
212 	mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
213 
214 	parport_set_timeout (pp->pdev,
215 			     (file->f_flags & O_NONBLOCK) ?
216 			     PARPORT_INACTIVITY_O_NONBLOCK :
217 			     pp->default_inactivity);
218 
219 	while (bytes_written < count) {
220 		ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
221 
222 		if (copy_from_user (kbuffer, buf + bytes_written, n)) {
223 			bytes_written = -EFAULT;
224 			break;
225 		}
226 
227 		if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
228 			/* do a fast EPP write */
229 			if (pport->ieee1284.mode & IEEE1284_ADDR) {
230 				wrote = pport->ops->epp_write_addr (pport,
231 					kbuffer, n, PARPORT_EPP_FAST);
232 			} else {
233 				wrote = pport->ops->epp_write_data (pport,
234 					kbuffer, n, PARPORT_EPP_FAST);
235 			}
236 		} else {
237 			wrote = parport_write (pp->pdev->port, kbuffer, n);
238 		}
239 
240 		if (wrote <= 0) {
241 			if (!bytes_written) {
242 				bytes_written = wrote;
243 			}
244 			break;
245 		}
246 
247 		bytes_written += wrote;
248 
249 		if (file->f_flags & O_NONBLOCK) {
250 			if (!bytes_written)
251 				bytes_written = -EAGAIN;
252 			break;
253 		}
254 
255 		if (signal_pending (current)) {
256 			if (!bytes_written) {
257 				bytes_written = -EINTR;
258 			}
259 			break;
260 		}
261 
262 		cond_resched();
263 	}
264 
265 	parport_set_timeout (pp->pdev, pp->default_inactivity);
266 
267 	kfree (kbuffer);
268 	pp_enable_irq (pp);
269 	return bytes_written;
270 }
271 
272 static void pp_irq (int irq, void * private, struct pt_regs * unused)
273 {
274 	struct pp_struct * pp = (struct pp_struct *) private;
275 
276 	if (pp->irqresponse) {
277 		parport_write_control (pp->pdev->port, pp->irqctl);
278 		pp->irqresponse = 0;
279 	}
280 
281 	atomic_inc (&pp->irqc);
282 	wake_up_interruptible (&pp->irq_wait);
283 }
284 
285 static int register_device (int minor, struct pp_struct *pp)
286 {
287 	struct parport *port;
288 	struct pardevice * pdev = NULL;
289 	char *name;
290 	int fl;
291 
292 	name = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
293 	if (name == NULL)
294 		return -ENOMEM;
295 
296 	sprintf (name, CHRDEV "%x", minor);
297 
298 	port = parport_find_number (minor);
299 	if (!port) {
300 		printk (KERN_WARNING "%s: no associated port!\n", name);
301 		kfree (name);
302 		return -ENXIO;
303 	}
304 
305 	fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
306 	pdev = parport_register_device (port, name, NULL,
307 					NULL, pp_irq, fl, pp);
308 	parport_put_port (port);
309 
310 	if (!pdev) {
311 		printk (KERN_WARNING "%s: failed to register device!\n", name);
312 		kfree (name);
313 		return -ENXIO;
314 	}
315 
316 	pp->pdev = pdev;
317 	printk (KERN_DEBUG "%s: registered pardevice\n", name);
318 	return 0;
319 }
320 
321 static enum ieee1284_phase init_phase (int mode)
322 {
323 	switch (mode & ~(IEEE1284_DEVICEID
324 			 | IEEE1284_ADDR)) {
325 	case IEEE1284_MODE_NIBBLE:
326 	case IEEE1284_MODE_BYTE:
327 		return IEEE1284_PH_REV_IDLE;
328 	}
329 	return IEEE1284_PH_FWD_IDLE;
330 }
331 
332 static int pp_ioctl(struct inode *inode, struct file *file,
333 		    unsigned int cmd, unsigned long arg)
334 {
335 	unsigned int minor = iminor(inode);
336 	struct pp_struct *pp = file->private_data;
337 	struct parport * port;
338 	void __user *argp = (void __user *)arg;
339 
340 	/* First handle the cases that don't take arguments. */
341 	switch (cmd) {
342 	case PPCLAIM:
343 	    {
344 		struct ieee1284_info *info;
345 		int ret;
346 
347 		if (pp->flags & PP_CLAIMED) {
348 			printk (KERN_DEBUG CHRDEV
349 				"%x: you've already got it!\n", minor);
350 			return -EINVAL;
351 		}
352 
353 		/* Deferred device registration. */
354 		if (!pp->pdev) {
355 			int err = register_device (minor, pp);
356 			if (err) {
357 				return err;
358 			}
359 		}
360 
361 		ret = parport_claim_or_block (pp->pdev);
362 		if (ret < 0)
363 			return ret;
364 
365 		pp->flags |= PP_CLAIMED;
366 
367 		/* For interrupt-reporting to work, we need to be
368 		 * informed of each interrupt. */
369 		pp_enable_irq (pp);
370 
371 		/* We may need to fix up the state machine. */
372 		info = &pp->pdev->port->ieee1284;
373 		pp->saved_state.mode = info->mode;
374 		pp->saved_state.phase = info->phase;
375 		info->mode = pp->state.mode;
376 		info->phase = pp->state.phase;
377 		pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
378 		parport_set_timeout (pp->pdev, pp->default_inactivity);
379 
380 		return 0;
381 	    }
382 	case PPEXCL:
383 		if (pp->pdev) {
384 			printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
385 				"already registered\n", minor);
386 			if (pp->flags & PP_EXCL)
387 				/* But it's not really an error. */
388 				return 0;
389 			/* There's no chance of making the driver happy. */
390 			return -EINVAL;
391 		}
392 
393 		/* Just remember to register the device exclusively
394 		 * when we finally do the registration. */
395 		pp->flags |= PP_EXCL;
396 		return 0;
397 	case PPSETMODE:
398 	    {
399 		int mode;
400 		if (copy_from_user (&mode, argp, sizeof (mode)))
401 			return -EFAULT;
402 		/* FIXME: validate mode */
403 		pp->state.mode = mode;
404 		pp->state.phase = init_phase (mode);
405 
406 		if (pp->flags & PP_CLAIMED) {
407 			pp->pdev->port->ieee1284.mode = mode;
408 			pp->pdev->port->ieee1284.phase = pp->state.phase;
409 		}
410 
411 		return 0;
412 	    }
413 	case PPGETMODE:
414 	    {
415 		int mode;
416 
417 		if (pp->flags & PP_CLAIMED) {
418 			mode = pp->pdev->port->ieee1284.mode;
419 		} else {
420 			mode = pp->state.mode;
421 		}
422 		if (copy_to_user (argp, &mode, sizeof (mode))) {
423 			return -EFAULT;
424 		}
425 		return 0;
426 	    }
427 	case PPSETPHASE:
428 	    {
429 		int phase;
430 		if (copy_from_user (&phase, argp, sizeof (phase))) {
431 			return -EFAULT;
432 		}
433 		/* FIXME: validate phase */
434 		pp->state.phase = phase;
435 
436 		if (pp->flags & PP_CLAIMED) {
437 			pp->pdev->port->ieee1284.phase = phase;
438 		}
439 
440 		return 0;
441 	    }
442 	case PPGETPHASE:
443 	    {
444 		int phase;
445 
446 		if (pp->flags & PP_CLAIMED) {
447 			phase = pp->pdev->port->ieee1284.phase;
448 		} else {
449 			phase = pp->state.phase;
450 		}
451 		if (copy_to_user (argp, &phase, sizeof (phase))) {
452 			return -EFAULT;
453 		}
454 		return 0;
455 	    }
456 	case PPGETMODES:
457 	    {
458 		unsigned int modes;
459 
460 		port = parport_find_number (minor);
461 		if (!port)
462 			return -ENODEV;
463 
464 		modes = port->modes;
465 		if (copy_to_user (argp, &modes, sizeof (modes))) {
466 			return -EFAULT;
467 		}
468 		return 0;
469 	    }
470 	case PPSETFLAGS:
471 	    {
472 		int uflags;
473 
474 		if (copy_from_user (&uflags, argp, sizeof (uflags))) {
475 			return -EFAULT;
476 		}
477 		pp->flags &= ~PP_FLAGMASK;
478 		pp->flags |= (uflags & PP_FLAGMASK);
479 		return 0;
480 	    }
481 	case PPGETFLAGS:
482 	    {
483 		int uflags;
484 
485 		uflags = pp->flags & PP_FLAGMASK;
486 		if (copy_to_user (argp, &uflags, sizeof (uflags))) {
487 			return -EFAULT;
488 		}
489 		return 0;
490 	    }
491 	}	/* end switch() */
492 
493 	/* Everything else requires the port to be claimed, so check
494 	 * that now. */
495 	if ((pp->flags & PP_CLAIMED) == 0) {
496 		printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
497 			minor);
498 		return -EINVAL;
499 	}
500 
501 	port = pp->pdev->port;
502 	switch (cmd) {
503 		struct ieee1284_info *info;
504 		unsigned char reg;
505 		unsigned char mask;
506 		int mode;
507 		int ret;
508 		struct timeval par_timeout;
509 		long to_jiffies;
510 
511 	case PPRSTATUS:
512 		reg = parport_read_status (port);
513 		if (copy_to_user (argp, &reg, sizeof (reg)))
514 			return -EFAULT;
515 		return 0;
516 	case PPRDATA:
517 		reg = parport_read_data (port);
518 		if (copy_to_user (argp, &reg, sizeof (reg)))
519 			return -EFAULT;
520 		return 0;
521 	case PPRCONTROL:
522 		reg = parport_read_control (port);
523 		if (copy_to_user (argp, &reg, sizeof (reg)))
524 			return -EFAULT;
525 		return 0;
526 	case PPYIELD:
527 		parport_yield_blocking (pp->pdev);
528 		return 0;
529 
530 	case PPRELEASE:
531 		/* Save the state machine's state. */
532 		info = &pp->pdev->port->ieee1284;
533 		pp->state.mode = info->mode;
534 		pp->state.phase = info->phase;
535 		info->mode = pp->saved_state.mode;
536 		info->phase = pp->saved_state.phase;
537 		parport_release (pp->pdev);
538 		pp->flags &= ~PP_CLAIMED;
539 		return 0;
540 
541 	case PPWCONTROL:
542 		if (copy_from_user (&reg, argp, sizeof (reg)))
543 			return -EFAULT;
544 		parport_write_control (port, reg);
545 		return 0;
546 
547 	case PPWDATA:
548 		if (copy_from_user (&reg, argp, sizeof (reg)))
549 			return -EFAULT;
550 		parport_write_data (port, reg);
551 		return 0;
552 
553 	case PPFCONTROL:
554 		if (copy_from_user (&mask, argp,
555 				    sizeof (mask)))
556 			return -EFAULT;
557 		if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
558 				    sizeof (reg)))
559 			return -EFAULT;
560 		parport_frob_control (port, mask, reg);
561 		return 0;
562 
563 	case PPDATADIR:
564 		if (copy_from_user (&mode, argp, sizeof (mode)))
565 			return -EFAULT;
566 		if (mode)
567 			port->ops->data_reverse (port);
568 		else
569 			port->ops->data_forward (port);
570 		return 0;
571 
572 	case PPNEGOT:
573 		if (copy_from_user (&mode, argp, sizeof (mode)))
574 			return -EFAULT;
575 		switch ((ret = parport_negotiate (port, mode))) {
576 		case 0: break;
577 		case -1: /* handshake failed, peripheral not IEEE 1284 */
578 			ret = -EIO;
579 			break;
580 		case 1:  /* handshake succeeded, peripheral rejected mode */
581 			ret = -ENXIO;
582 			break;
583 		}
584 		pp_enable_irq (pp);
585 		return ret;
586 
587 	case PPWCTLONIRQ:
588 		if (copy_from_user (&reg, argp, sizeof (reg)))
589 			return -EFAULT;
590 
591 		/* Remember what to set the control lines to, for next
592 		 * time we get an interrupt. */
593 		pp->irqctl = reg;
594 		pp->irqresponse = 1;
595 		return 0;
596 
597 	case PPCLRIRQ:
598 		ret = atomic_read (&pp->irqc);
599 		if (copy_to_user (argp, &ret, sizeof (ret)))
600 			return -EFAULT;
601 		atomic_sub (ret, &pp->irqc);
602 		return 0;
603 
604 	case PPSETTIME:
605 		if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
606 			return -EFAULT;
607 		}
608 		/* Convert to jiffies, place in pp->pdev->timeout */
609 		if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
610 			return -EINVAL;
611 		}
612 		to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
613 		to_jiffies += par_timeout.tv_sec * (long)HZ;
614 		if (to_jiffies <= 0) {
615 			return -EINVAL;
616 		}
617 		pp->pdev->timeout = to_jiffies;
618 		return 0;
619 
620 	case PPGETTIME:
621 		to_jiffies = pp->pdev->timeout;
622 		par_timeout.tv_sec = to_jiffies / HZ;
623 		par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
624 		if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
625 			return -EFAULT;
626 		return 0;
627 
628 	default:
629 		printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
630 			cmd);
631 		return -EINVAL;
632 	}
633 
634 	/* Keep the compiler happy */
635 	return 0;
636 }
637 
638 static int pp_open (struct inode * inode, struct file * file)
639 {
640 	unsigned int minor = iminor(inode);
641 	struct pp_struct *pp;
642 
643 	if (minor >= PARPORT_MAX)
644 		return -ENXIO;
645 
646 	pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
647 	if (!pp)
648 		return -ENOMEM;
649 
650 	pp->state.mode = IEEE1284_MODE_COMPAT;
651 	pp->state.phase = init_phase (pp->state.mode);
652 	pp->flags = 0;
653 	pp->irqresponse = 0;
654 	atomic_set (&pp->irqc, 0);
655 	init_waitqueue_head (&pp->irq_wait);
656 
657 	/* Defer the actual device registration until the first claim.
658 	 * That way, we know whether or not the driver wants to have
659 	 * exclusive access to the port (PPEXCL).
660 	 */
661 	pp->pdev = NULL;
662 	file->private_data = pp;
663 
664 	return 0;
665 }
666 
667 static int pp_release (struct inode * inode, struct file * file)
668 {
669 	unsigned int minor = iminor(inode);
670 	struct pp_struct *pp = file->private_data;
671 	int compat_negot;
672 
673 	compat_negot = 0;
674 	if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
675 	    (pp->state.mode != IEEE1284_MODE_COMPAT)) {
676 	    	struct ieee1284_info *info;
677 
678 		/* parport released, but not in compatibility mode */
679 		parport_claim_or_block (pp->pdev);
680 		pp->flags |= PP_CLAIMED;
681 		info = &pp->pdev->port->ieee1284;
682 		pp->saved_state.mode = info->mode;
683 		pp->saved_state.phase = info->phase;
684 		info->mode = pp->state.mode;
685 		info->phase = pp->state.phase;
686 		compat_negot = 1;
687 	} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
688 	    (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
689 		compat_negot = 2;
690 	}
691 	if (compat_negot) {
692 		parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
693 		printk (KERN_DEBUG CHRDEV
694 			"%x: negotiated back to compatibility mode because "
695 			"user-space forgot\n", minor);
696 	}
697 
698 	if (pp->flags & PP_CLAIMED) {
699 		struct ieee1284_info *info;
700 
701 		info = &pp->pdev->port->ieee1284;
702 		pp->state.mode = info->mode;
703 		pp->state.phase = info->phase;
704 		info->mode = pp->saved_state.mode;
705 		info->phase = pp->saved_state.phase;
706 		parport_release (pp->pdev);
707 		if (compat_negot != 1) {
708 			printk (KERN_DEBUG CHRDEV "%x: released pardevice "
709 				"because user-space forgot\n", minor);
710 		}
711 	}
712 
713 	if (pp->pdev) {
714 		const char *name = pp->pdev->name;
715 		parport_unregister_device (pp->pdev);
716 		kfree (name);
717 		pp->pdev = NULL;
718 		printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
719 			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 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 	.ioctl		= pp_ioctl,
749 	.open		= pp_open,
750 	.release	= pp_release,
751 };
752 
753 static void pp_attach(struct parport *port)
754 {
755 	class_device_create(ppdev_class, NULL, MKDEV(PP_MAJOR, port->number),
756 			NULL, "parport%d", port->number);
757 }
758 
759 static void pp_detach(struct parport *port)
760 {
761 	class_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 i, 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 	devfs_mk_dir("parports");
785 	for (i = 0; i < PARPORT_MAX; i++) {
786 		devfs_mk_cdev(MKDEV(PP_MAJOR, i),
787 				S_IFCHR | S_IRUGO | S_IWUGO, "parports/%d", i);
788 	}
789 	if (parport_register_driver(&pp_driver)) {
790 		printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
791 		goto out_class;
792 	}
793 
794 	printk (KERN_INFO PP_VERSION "\n");
795 	goto out;
796 
797 out_class:
798 	for (i = 0; i < PARPORT_MAX; i++)
799 		devfs_remove("parports/%d", i);
800 	devfs_remove("parports");
801 	class_destroy(ppdev_class);
802 out_chrdev:
803 	unregister_chrdev(PP_MAJOR, CHRDEV);
804 out:
805 	return err;
806 }
807 
808 static void __exit ppdev_cleanup (void)
809 {
810 	int i;
811 	/* Clean up all parport stuff */
812 	for (i = 0; i < PARPORT_MAX; i++)
813 		devfs_remove("parports/%d", i);
814 	parport_unregister_driver(&pp_driver);
815 	devfs_remove("parports");
816 	class_destroy(ppdev_class);
817 	unregister_chrdev (PP_MAJOR, CHRDEV);
818 }
819 
820 module_init(ppdev_init);
821 module_exit(ppdev_cleanup);
822 
823 MODULE_LICENSE("GPL");
824 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
825