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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
76struct 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
100static DEFINE_MUTEX(pp_do_mutex);
101static 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
107static 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
189static 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
271static 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
284static 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
318static 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
329static 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 parport_put_port(port);
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, ®, sizeof (reg)))
509 return -EFAULT;
510 return 0;
511 case PPRDATA:
512 reg = parport_read_data (port);
513 if (copy_to_user (argp, ®, sizeof (reg)))
514 return -EFAULT;
515 return 0;
516 case PPRCONTROL:
517 reg = parport_read_control (port);
518 if (copy_to_user (argp, ®, 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 (®, argp, sizeof (reg)))
538 return -EFAULT;
539 parport_write_control (port, reg);
540 return 0;
541
542 case PPWDATA:
543 if (copy_from_user (®, 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 (®, 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 (®, 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 memset(&par_timeout, 0, sizeof(par_timeout));
618 par_timeout.tv_sec = to_jiffies / HZ;
619 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
620 if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
621 return -EFAULT;
622 return 0;
623
624 default:
625 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
626 return -EINVAL;
627 }
628
629 /* Keep the compiler happy */
630 return 0;
631}
632
633static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
634{
635 long ret;
636 mutex_lock(&pp_do_mutex);
637 ret = pp_do_ioctl(file, cmd, arg);
638 mutex_unlock(&pp_do_mutex);
639 return ret;
640}
641
642static int pp_open (struct inode * inode, struct file * file)
643{
644 unsigned int minor = iminor(inode);
645 struct pp_struct *pp;
646
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
671static 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 */
730static 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
742static struct class *ppdev_class;
743
744static 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
755static 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
761static void pp_detach(struct parport *port)
762{
763 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
764}
765
766static struct parport_driver pp_driver = {
767 .name = CHRDEV,
768 .attach = pp_attach,
769 .detach = pp_detach,
770};
771
772static 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
794out_class:
795 class_destroy(ppdev_class);
796out_chrdev:
797 unregister_chrdev(PP_MAJOR, CHRDEV);
798out:
799 return err;
800}
801
802static 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
810module_init(ppdev_init);
811module_exit(ppdev_cleanup);
812
813MODULE_LICENSE("GPL");
814MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * linux/drivers/char/ppdev.c
4 *
5 * This is the code behind /dev/parport* -- it allows a user-space
6 * application to use the parport subsystem.
7 *
8 * Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
9 *
10 * A /dev/parportx device node represents an arbitrary device
11 * on port 'x'. The following operations are possible:
12 *
13 * open do nothing, set up default IEEE 1284 protocol to be COMPAT
14 * close release port and unregister device (if necessary)
15 * ioctl
16 * EXCL register device exclusively (may fail)
17 * CLAIM (register device first time) parport_claim_or_block
18 * RELEASE parport_release
19 * SETMODE set the IEEE 1284 protocol to use for read/write
20 * SETPHASE set the IEEE 1284 phase of a particular mode. Not to be
21 * confused with ioctl(fd, SETPHASER, &stun). ;-)
22 * DATADIR data_forward / data_reverse
23 * WDATA write_data
24 * RDATA read_data
25 * WCONTROL write_control
26 * RCONTROL read_control
27 * FCONTROL frob_control
28 * RSTATUS read_status
29 * NEGOT parport_negotiate
30 * YIELD parport_yield_blocking
31 * WCTLONIRQ on interrupt, set control lines
32 * CLRIRQ clear (and return) interrupt count
33 * SETTIME sets device timeout (struct timeval)
34 * GETTIME gets device timeout (struct timeval)
35 * GETMODES gets hardware supported modes (unsigned int)
36 * GETMODE gets the current IEEE1284 mode
37 * GETPHASE gets the current IEEE1284 phase
38 * GETFLAGS gets current (user-visible) flags
39 * SETFLAGS sets current (user-visible) flags
40 * read/write read or write in current IEEE 1284 protocol
41 * select wait for interrupt (in readfds)
42 *
43 * Changes:
44 * Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
45 *
46 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
47 * - On error, copy_from_user and copy_to_user do not return -EFAULT,
48 * They return the positive number of bytes *not* copied due to address
49 * space errors.
50 *
51 * Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
52 * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
53 */
54
55#include <linux/module.h>
56#include <linux/init.h>
57#include <linux/sched/signal.h>
58#include <linux/device.h>
59#include <linux/ioctl.h>
60#include <linux/parport.h>
61#include <linux/ctype.h>
62#include <linux/poll.h>
63#include <linux/slab.h>
64#include <linux/major.h>
65#include <linux/ppdev.h>
66#include <linux/mutex.h>
67#include <linux/uaccess.h>
68#include <linux/compat.h>
69
70#define PP_VERSION "ppdev: user-space parallel port driver"
71#define CHRDEV "ppdev"
72
73struct pp_struct {
74 struct pardevice *pdev;
75 wait_queue_head_t irq_wait;
76 atomic_t irqc;
77 unsigned int flags;
78 int irqresponse;
79 unsigned char irqctl;
80 struct ieee1284_info state;
81 struct ieee1284_info saved_state;
82 long default_inactivity;
83 int index;
84};
85
86/* should we use PARDEVICE_MAX here? */
87static struct device *devices[PARPORT_MAX];
88
89static DEFINE_IDA(ida_index);
90
91/* pp_struct.flags bitfields */
92#define PP_CLAIMED (1<<0)
93#define PP_EXCL (1<<1)
94
95/* Other constants */
96#define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
97#define PP_BUFFER_SIZE 1024
98#define PARDEVICE_MAX 8
99
100static DEFINE_MUTEX(pp_do_mutex);
101
102/* define fixed sized ioctl cmd for y2038 migration */
103#define PPGETTIME32 _IOR(PP_IOCTL, 0x95, s32[2])
104#define PPSETTIME32 _IOW(PP_IOCTL, 0x96, s32[2])
105#define PPGETTIME64 _IOR(PP_IOCTL, 0x95, s64[2])
106#define PPSETTIME64 _IOW(PP_IOCTL, 0x96, s64[2])
107
108static inline void pp_enable_irq(struct pp_struct *pp)
109{
110 struct parport *port = pp->pdev->port;
111
112 port->ops->enable_irq(port);
113}
114
115static ssize_t pp_read(struct file *file, char __user *buf, size_t count,
116 loff_t *ppos)
117{
118 unsigned int minor = iminor(file_inode(file));
119 struct pp_struct *pp = file->private_data;
120 char *kbuffer;
121 ssize_t bytes_read = 0;
122 struct parport *pport;
123 int mode;
124
125 if (!(pp->flags & PP_CLAIMED)) {
126 /* Don't have the port claimed */
127 pr_debug(CHRDEV "%x: claim the port first\n", minor);
128 return -EINVAL;
129 }
130
131 /* Trivial case. */
132 if (count == 0)
133 return 0;
134
135 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
136 if (!kbuffer)
137 return -ENOMEM;
138 pport = pp->pdev->port;
139 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
140
141 parport_set_timeout(pp->pdev,
142 (file->f_flags & O_NONBLOCK) ?
143 PARPORT_INACTIVITY_O_NONBLOCK :
144 pp->default_inactivity);
145
146 while (bytes_read == 0) {
147 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
148
149 if (mode == IEEE1284_MODE_EPP) {
150 /* various specials for EPP mode */
151 int flags = 0;
152 size_t (*fn)(struct parport *, void *, size_t, int);
153
154 if (pp->flags & PP_W91284PIC)
155 flags |= PARPORT_W91284PIC;
156 if (pp->flags & PP_FASTREAD)
157 flags |= PARPORT_EPP_FAST;
158 if (pport->ieee1284.mode & IEEE1284_ADDR)
159 fn = pport->ops->epp_read_addr;
160 else
161 fn = pport->ops->epp_read_data;
162 bytes_read = (*fn)(pport, kbuffer, need, flags);
163 } else {
164 bytes_read = parport_read(pport, kbuffer, need);
165 }
166
167 if (bytes_read != 0)
168 break;
169
170 if (file->f_flags & O_NONBLOCK) {
171 bytes_read = -EAGAIN;
172 break;
173 }
174
175 if (signal_pending(current)) {
176 bytes_read = -ERESTARTSYS;
177 break;
178 }
179
180 cond_resched();
181 }
182
183 parport_set_timeout(pp->pdev, pp->default_inactivity);
184
185 if (bytes_read > 0 && copy_to_user(buf, kbuffer, bytes_read))
186 bytes_read = -EFAULT;
187
188 kfree(kbuffer);
189 pp_enable_irq(pp);
190 return bytes_read;
191}
192
193static ssize_t pp_write(struct file *file, const char __user *buf,
194 size_t count, loff_t *ppos)
195{
196 unsigned int minor = iminor(file_inode(file));
197 struct pp_struct *pp = file->private_data;
198 char *kbuffer;
199 ssize_t bytes_written = 0;
200 ssize_t wrote;
201 int mode;
202 struct parport *pport;
203
204 if (!(pp->flags & PP_CLAIMED)) {
205 /* Don't have the port claimed */
206 pr_debug(CHRDEV "%x: claim the port first\n", minor);
207 return -EINVAL;
208 }
209
210 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
211 if (!kbuffer)
212 return -ENOMEM;
213
214 pport = pp->pdev->port;
215 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
216
217 parport_set_timeout(pp->pdev,
218 (file->f_flags & O_NONBLOCK) ?
219 PARPORT_INACTIVITY_O_NONBLOCK :
220 pp->default_inactivity);
221
222 while (bytes_written < count) {
223 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
224
225 if (copy_from_user(kbuffer, buf + bytes_written, n)) {
226 bytes_written = -EFAULT;
227 break;
228 }
229
230 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
231 /* do a fast EPP write */
232 if (pport->ieee1284.mode & IEEE1284_ADDR) {
233 wrote = pport->ops->epp_write_addr(pport,
234 kbuffer, n, PARPORT_EPP_FAST);
235 } else {
236 wrote = pport->ops->epp_write_data(pport,
237 kbuffer, n, PARPORT_EPP_FAST);
238 }
239 } else {
240 wrote = parport_write(pp->pdev->port, kbuffer, n);
241 }
242
243 if (wrote <= 0) {
244 if (!bytes_written)
245 bytes_written = wrote;
246 break;
247 }
248
249 bytes_written += wrote;
250
251 if (file->f_flags & O_NONBLOCK) {
252 if (!bytes_written)
253 bytes_written = -EAGAIN;
254 break;
255 }
256
257 if (signal_pending(current))
258 break;
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
270static 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
283static int register_device(int minor, struct pp_struct *pp)
284{
285 struct parport *port;
286 struct pardevice *pdev = NULL;
287 char *name;
288 struct pardev_cb ppdev_cb;
289 int rc = 0, index;
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 pr_warn("%s: no associated port!\n", name);
298 rc = -ENXIO;
299 goto err;
300 }
301
302 index = ida_alloc(&ida_index, GFP_KERNEL);
303 memset(&ppdev_cb, 0, sizeof(ppdev_cb));
304 ppdev_cb.irq_func = pp_irq;
305 ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
306 ppdev_cb.private = pp;
307 pdev = parport_register_dev_model(port, name, &ppdev_cb, index);
308 parport_put_port(port);
309
310 if (!pdev) {
311 pr_warn("%s: failed to register device!\n", name);
312 rc = -ENXIO;
313 ida_free(&ida_index, index);
314 goto err;
315 }
316
317 pp->pdev = pdev;
318 pp->index = index;
319 dev_dbg(&pdev->dev, "registered pardevice\n");
320err:
321 kfree(name);
322 return rc;
323}
324
325static enum ieee1284_phase init_phase(int mode)
326{
327 switch (mode & ~(IEEE1284_DEVICEID
328 | IEEE1284_ADDR)) {
329 case IEEE1284_MODE_NIBBLE:
330 case IEEE1284_MODE_BYTE:
331 return IEEE1284_PH_REV_IDLE;
332 }
333 return IEEE1284_PH_FWD_IDLE;
334}
335
336static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
337{
338 long to_jiffies;
339
340 if ((tv_sec < 0) || (tv_usec < 0))
341 return -EINVAL;
342
343 to_jiffies = usecs_to_jiffies(tv_usec);
344 to_jiffies += tv_sec * HZ;
345 if (to_jiffies <= 0)
346 return -EINVAL;
347
348 pdev->timeout = to_jiffies;
349 return 0;
350}
351
352static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
353{
354 unsigned int minor = iminor(file_inode(file));
355 struct pp_struct *pp = file->private_data;
356 struct parport *port;
357 void __user *argp = (void __user *)arg;
358 struct ieee1284_info *info;
359 unsigned char reg;
360 unsigned char mask;
361 int mode;
362 s32 time32[2];
363 s64 time64[2];
364 struct timespec64 ts;
365 int ret;
366
367 /* First handle the cases that don't take arguments. */
368 switch (cmd) {
369 case PPCLAIM:
370 {
371 if (pp->flags & PP_CLAIMED) {
372 dev_dbg(&pp->pdev->dev, "you've already got it!\n");
373 return -EINVAL;
374 }
375
376 /* Deferred device registration. */
377 if (!pp->pdev) {
378 int err = register_device(minor, pp);
379
380 if (err)
381 return err;
382 }
383
384 ret = parport_claim_or_block(pp->pdev);
385 if (ret < 0)
386 return ret;
387
388 pp->flags |= PP_CLAIMED;
389
390 /* For interrupt-reporting to work, we need to be
391 * informed of each interrupt. */
392 pp_enable_irq(pp);
393
394 /* We may need to fix up the state machine. */
395 info = &pp->pdev->port->ieee1284;
396 pp->saved_state.mode = info->mode;
397 pp->saved_state.phase = info->phase;
398 info->mode = pp->state.mode;
399 info->phase = pp->state.phase;
400 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
401 parport_set_timeout(pp->pdev, pp->default_inactivity);
402
403 return 0;
404 }
405 case PPEXCL:
406 if (pp->pdev) {
407 dev_dbg(&pp->pdev->dev,
408 "too late for PPEXCL; already registered\n");
409 if (pp->flags & PP_EXCL)
410 /* But it's not really an error. */
411 return 0;
412 /* There's no chance of making the driver happy. */
413 return -EINVAL;
414 }
415
416 /* Just remember to register the device exclusively
417 * when we finally do the registration. */
418 pp->flags |= PP_EXCL;
419 return 0;
420 case PPSETMODE:
421 {
422 int mode;
423
424 if (copy_from_user(&mode, argp, sizeof(mode)))
425 return -EFAULT;
426 /* FIXME: validate mode */
427 pp->state.mode = mode;
428 pp->state.phase = init_phase(mode);
429
430 if (pp->flags & PP_CLAIMED) {
431 pp->pdev->port->ieee1284.mode = mode;
432 pp->pdev->port->ieee1284.phase = pp->state.phase;
433 }
434
435 return 0;
436 }
437 case PPGETMODE:
438 {
439 int mode;
440
441 if (pp->flags & PP_CLAIMED)
442 mode = pp->pdev->port->ieee1284.mode;
443 else
444 mode = pp->state.mode;
445
446 if (copy_to_user(argp, &mode, sizeof(mode)))
447 return -EFAULT;
448 return 0;
449 }
450 case PPSETPHASE:
451 {
452 int phase;
453
454 if (copy_from_user(&phase, argp, sizeof(phase)))
455 return -EFAULT;
456
457 /* FIXME: validate phase */
458 pp->state.phase = phase;
459
460 if (pp->flags & PP_CLAIMED)
461 pp->pdev->port->ieee1284.phase = phase;
462
463 return 0;
464 }
465 case PPGETPHASE:
466 {
467 int phase;
468
469 if (pp->flags & PP_CLAIMED)
470 phase = pp->pdev->port->ieee1284.phase;
471 else
472 phase = pp->state.phase;
473 if (copy_to_user(argp, &phase, sizeof(phase)))
474 return -EFAULT;
475 return 0;
476 }
477 case PPGETMODES:
478 {
479 unsigned int modes;
480
481 port = parport_find_number(minor);
482 if (!port)
483 return -ENODEV;
484
485 modes = port->modes;
486 parport_put_port(port);
487 if (copy_to_user(argp, &modes, sizeof(modes)))
488 return -EFAULT;
489 return 0;
490 }
491 case PPSETFLAGS:
492 {
493 int uflags;
494
495 if (copy_from_user(&uflags, argp, sizeof(uflags)))
496 return -EFAULT;
497 pp->flags &= ~PP_FLAGMASK;
498 pp->flags |= (uflags & PP_FLAGMASK);
499 return 0;
500 }
501 case PPGETFLAGS:
502 {
503 int uflags;
504
505 uflags = pp->flags & PP_FLAGMASK;
506 if (copy_to_user(argp, &uflags, sizeof(uflags)))
507 return -EFAULT;
508 return 0;
509 }
510 } /* end switch() */
511
512 /* Everything else requires the port to be claimed, so check
513 * that now. */
514 if ((pp->flags & PP_CLAIMED) == 0) {
515 pr_debug(CHRDEV "%x: claim the port first\n", minor);
516 return -EINVAL;
517 }
518
519 port = pp->pdev->port;
520 switch (cmd) {
521 case PPRSTATUS:
522 reg = parport_read_status(port);
523 if (copy_to_user(argp, ®, sizeof(reg)))
524 return -EFAULT;
525 return 0;
526 case PPRDATA:
527 reg = parport_read_data(port);
528 if (copy_to_user(argp, ®, sizeof(reg)))
529 return -EFAULT;
530 return 0;
531 case PPRCONTROL:
532 reg = parport_read_control(port);
533 if (copy_to_user(argp, ®, sizeof(reg)))
534 return -EFAULT;
535 return 0;
536 case PPYIELD:
537 parport_yield_blocking(pp->pdev);
538 return 0;
539
540 case PPRELEASE:
541 /* Save the state machine's state. */
542 info = &pp->pdev->port->ieee1284;
543 pp->state.mode = info->mode;
544 pp->state.phase = info->phase;
545 info->mode = pp->saved_state.mode;
546 info->phase = pp->saved_state.phase;
547 parport_release(pp->pdev);
548 pp->flags &= ~PP_CLAIMED;
549 return 0;
550
551 case PPWCONTROL:
552 if (copy_from_user(®, argp, sizeof(reg)))
553 return -EFAULT;
554 parport_write_control(port, reg);
555 return 0;
556
557 case PPWDATA:
558 if (copy_from_user(®, argp, sizeof(reg)))
559 return -EFAULT;
560 parport_write_data(port, reg);
561 return 0;
562
563 case PPFCONTROL:
564 if (copy_from_user(&mask, argp,
565 sizeof(mask)))
566 return -EFAULT;
567 if (copy_from_user(®, 1 + (unsigned char __user *) arg,
568 sizeof(reg)))
569 return -EFAULT;
570 parport_frob_control(port, mask, reg);
571 return 0;
572
573 case PPDATADIR:
574 if (copy_from_user(&mode, argp, sizeof(mode)))
575 return -EFAULT;
576 if (mode)
577 port->ops->data_reverse(port);
578 else
579 port->ops->data_forward(port);
580 return 0;
581
582 case PPNEGOT:
583 if (copy_from_user(&mode, argp, sizeof(mode)))
584 return -EFAULT;
585 switch ((ret = parport_negotiate(port, mode))) {
586 case 0: break;
587 case -1: /* handshake failed, peripheral not IEEE 1284 */
588 ret = -EIO;
589 break;
590 case 1: /* handshake succeeded, peripheral rejected mode */
591 ret = -ENXIO;
592 break;
593 }
594 pp_enable_irq(pp);
595 return ret;
596
597 case PPWCTLONIRQ:
598 if (copy_from_user(®, argp, sizeof(reg)))
599 return -EFAULT;
600
601 /* Remember what to set the control lines to, for next
602 * time we get an interrupt. */
603 pp->irqctl = reg;
604 pp->irqresponse = 1;
605 return 0;
606
607 case PPCLRIRQ:
608 ret = atomic_read(&pp->irqc);
609 if (copy_to_user(argp, &ret, sizeof(ret)))
610 return -EFAULT;
611 atomic_sub(ret, &pp->irqc);
612 return 0;
613
614 case PPSETTIME32:
615 if (copy_from_user(time32, argp, sizeof(time32)))
616 return -EFAULT;
617
618 if ((time32[0] < 0) || (time32[1] < 0))
619 return -EINVAL;
620
621 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
622
623 case PPSETTIME64:
624 if (copy_from_user(time64, argp, sizeof(time64)))
625 return -EFAULT;
626
627 if ((time64[0] < 0) || (time64[1] < 0))
628 return -EINVAL;
629
630 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
631 time64[1] >>= 32;
632
633 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
634
635 case PPGETTIME32:
636 jiffies_to_timespec64(pp->pdev->timeout, &ts);
637 time32[0] = ts.tv_sec;
638 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
639
640 if (copy_to_user(argp, time32, sizeof(time32)))
641 return -EFAULT;
642
643 return 0;
644
645 case PPGETTIME64:
646 jiffies_to_timespec64(pp->pdev->timeout, &ts);
647 time64[0] = ts.tv_sec;
648 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
649
650 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
651 time64[1] <<= 32;
652
653 if (copy_to_user(argp, time64, sizeof(time64)))
654 return -EFAULT;
655
656 return 0;
657
658 default:
659 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
660 return -EINVAL;
661 }
662
663 /* Keep the compiler happy */
664 return 0;
665}
666
667static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
668{
669 long ret;
670
671 mutex_lock(&pp_do_mutex);
672 ret = pp_do_ioctl(file, cmd, arg);
673 mutex_unlock(&pp_do_mutex);
674 return ret;
675}
676
677static int pp_open(struct inode *inode, struct file *file)
678{
679 unsigned int minor = iminor(inode);
680 struct pp_struct *pp;
681
682 if (minor >= PARPORT_MAX)
683 return -ENXIO;
684
685 pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
686 if (!pp)
687 return -ENOMEM;
688
689 pp->state.mode = IEEE1284_MODE_COMPAT;
690 pp->state.phase = init_phase(pp->state.mode);
691 pp->flags = 0;
692 pp->irqresponse = 0;
693 atomic_set(&pp->irqc, 0);
694 init_waitqueue_head(&pp->irq_wait);
695
696 /* Defer the actual device registration until the first claim.
697 * That way, we know whether or not the driver wants to have
698 * exclusive access to the port (PPEXCL).
699 */
700 pp->pdev = NULL;
701 file->private_data = pp;
702
703 return 0;
704}
705
706static int pp_release(struct inode *inode, struct file *file)
707{
708 unsigned int minor = iminor(inode);
709 struct pp_struct *pp = file->private_data;
710 int compat_negot;
711
712 compat_negot = 0;
713 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
714 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
715 struct ieee1284_info *info;
716
717 /* parport released, but not in compatibility mode */
718 parport_claim_or_block(pp->pdev);
719 pp->flags |= PP_CLAIMED;
720 info = &pp->pdev->port->ieee1284;
721 pp->saved_state.mode = info->mode;
722 pp->saved_state.phase = info->phase;
723 info->mode = pp->state.mode;
724 info->phase = pp->state.phase;
725 compat_negot = 1;
726 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
727 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
728 compat_negot = 2;
729 }
730 if (compat_negot) {
731 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
732 dev_dbg(&pp->pdev->dev,
733 "negotiated back to compatibility mode because user-space forgot\n");
734 }
735
736 if ((pp->flags & PP_CLAIMED) && pp->pdev) {
737 struct ieee1284_info *info;
738
739 info = &pp->pdev->port->ieee1284;
740 pp->state.mode = info->mode;
741 pp->state.phase = info->phase;
742 info->mode = pp->saved_state.mode;
743 info->phase = pp->saved_state.phase;
744 parport_release(pp->pdev);
745 if (compat_negot != 1) {
746 pr_debug(CHRDEV "%x: released pardevice "
747 "because user-space forgot\n", minor);
748 }
749 }
750
751 if (pp->pdev) {
752 parport_unregister_device(pp->pdev);
753 ida_free(&ida_index, pp->index);
754 pp->pdev = NULL;
755 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
756 }
757
758 kfree(pp);
759
760 return 0;
761}
762
763/* No kernel lock held - fine */
764static __poll_t pp_poll(struct file *file, poll_table *wait)
765{
766 struct pp_struct *pp = file->private_data;
767 __poll_t mask = 0;
768
769 poll_wait(file, &pp->irq_wait, wait);
770 if (atomic_read(&pp->irqc))
771 mask |= EPOLLIN | EPOLLRDNORM;
772
773 return mask;
774}
775
776static const struct class ppdev_class = {
777 .name = CHRDEV,
778};
779
780static const struct file_operations pp_fops = {
781 .owner = THIS_MODULE,
782 .llseek = no_llseek,
783 .read = pp_read,
784 .write = pp_write,
785 .poll = pp_poll,
786 .unlocked_ioctl = pp_ioctl,
787 .compat_ioctl = compat_ptr_ioctl,
788 .open = pp_open,
789 .release = pp_release,
790};
791
792static void pp_attach(struct parport *port)
793{
794 struct device *ret;
795
796 if (devices[port->number])
797 return;
798
799 ret = device_create(&ppdev_class, port->dev,
800 MKDEV(PP_MAJOR, port->number), NULL,
801 "parport%d", port->number);
802 if (IS_ERR(ret)) {
803 pr_err("Failed to create device parport%d\n",
804 port->number);
805 return;
806 }
807 devices[port->number] = ret;
808}
809
810static void pp_detach(struct parport *port)
811{
812 if (!devices[port->number])
813 return;
814
815 device_destroy(&ppdev_class, MKDEV(PP_MAJOR, port->number));
816 devices[port->number] = NULL;
817}
818
819static int pp_probe(struct pardevice *par_dev)
820{
821 struct device_driver *drv = par_dev->dev.driver;
822 int len = strlen(drv->name);
823
824 if (strncmp(par_dev->name, drv->name, len))
825 return -ENODEV;
826
827 return 0;
828}
829
830static struct parport_driver pp_driver = {
831 .name = CHRDEV,
832 .probe = pp_probe,
833 .match_port = pp_attach,
834 .detach = pp_detach,
835 .devmodel = true,
836};
837
838static int __init ppdev_init(void)
839{
840 int err = 0;
841
842 if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
843 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
844 return -EIO;
845 }
846 err = class_register(&ppdev_class);
847 if (err)
848 goto out_chrdev;
849
850 err = parport_register_driver(&pp_driver);
851 if (err < 0) {
852 pr_warn(CHRDEV ": unable to register with parport\n");
853 goto out_class;
854 }
855
856 pr_info(PP_VERSION "\n");
857 goto out;
858
859out_class:
860 class_unregister(&ppdev_class);
861out_chrdev:
862 unregister_chrdev(PP_MAJOR, CHRDEV);
863out:
864 return err;
865}
866
867static void __exit ppdev_cleanup(void)
868{
869 /* Clean up all parport stuff */
870 parport_unregister_driver(&pp_driver);
871 class_unregister(&ppdev_class);
872 unregister_chrdev(PP_MAJOR, CHRDEV);
873}
874
875module_init(ppdev_init);
876module_exit(ppdev_cleanup);
877
878MODULE_LICENSE("GPL");
879MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);