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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_simple_get(&ida_index, 0, 0, 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_simple_remove(&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_simple_remove(&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 struct class *ppdev_class;
777
778static const struct file_operations pp_fops = {
779 .owner = THIS_MODULE,
780 .llseek = no_llseek,
781 .read = pp_read,
782 .write = pp_write,
783 .poll = pp_poll,
784 .unlocked_ioctl = pp_ioctl,
785 .compat_ioctl = compat_ptr_ioctl,
786 .open = pp_open,
787 .release = pp_release,
788};
789
790static void pp_attach(struct parport *port)
791{
792 struct device *ret;
793
794 if (devices[port->number])
795 return;
796
797 ret = device_create(ppdev_class, port->dev,
798 MKDEV(PP_MAJOR, port->number), NULL,
799 "parport%d", port->number);
800 if (IS_ERR(ret)) {
801 pr_err("Failed to create device parport%d\n",
802 port->number);
803 return;
804 }
805 devices[port->number] = ret;
806}
807
808static void pp_detach(struct parport *port)
809{
810 if (!devices[port->number])
811 return;
812
813 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
814 devices[port->number] = NULL;
815}
816
817static int pp_probe(struct pardevice *par_dev)
818{
819 struct device_driver *drv = par_dev->dev.driver;
820 int len = strlen(drv->name);
821
822 if (strncmp(par_dev->name, drv->name, len))
823 return -ENODEV;
824
825 return 0;
826}
827
828static struct parport_driver pp_driver = {
829 .name = CHRDEV,
830 .probe = pp_probe,
831 .match_port = pp_attach,
832 .detach = pp_detach,
833 .devmodel = true,
834};
835
836static int __init ppdev_init(void)
837{
838 int err = 0;
839
840 if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
841 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
842 return -EIO;
843 }
844 ppdev_class = class_create(THIS_MODULE, CHRDEV);
845 if (IS_ERR(ppdev_class)) {
846 err = PTR_ERR(ppdev_class);
847 goto out_chrdev;
848 }
849 err = parport_register_driver(&pp_driver);
850 if (err < 0) {
851 pr_warn(CHRDEV ": unable to register with parport\n");
852 goto out_class;
853 }
854
855 pr_info(PP_VERSION "\n");
856 goto out;
857
858out_class:
859 class_destroy(ppdev_class);
860out_chrdev:
861 unregister_chrdev(PP_MAJOR, CHRDEV);
862out:
863 return err;
864}
865
866static void __exit ppdev_cleanup(void)
867{
868 /* Clean up all parport stuff */
869 parport_unregister_driver(&pp_driver);
870 class_destroy(ppdev_class);
871 unregister_chrdev(PP_MAJOR, CHRDEV);
872}
873
874module_init(ppdev_init);
875module_exit(ppdev_cleanup);
876
877MODULE_LICENSE("GPL");
878MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
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_inode(file));
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_inode(file));
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 break;
256
257 cond_resched();
258 }
259
260 parport_set_timeout (pp->pdev, pp->default_inactivity);
261
262 kfree (kbuffer);
263 pp_enable_irq (pp);
264 return bytes_written;
265}
266
267static void pp_irq (void *private)
268{
269 struct pp_struct *pp = private;
270
271 if (pp->irqresponse) {
272 parport_write_control (pp->pdev->port, pp->irqctl);
273 pp->irqresponse = 0;
274 }
275
276 atomic_inc (&pp->irqc);
277 wake_up_interruptible (&pp->irq_wait);
278}
279
280static int register_device (int minor, struct pp_struct *pp)
281{
282 struct parport *port;
283 struct pardevice * pdev = NULL;
284 char *name;
285 int fl;
286
287 name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
288 if (name == NULL)
289 return -ENOMEM;
290
291 port = parport_find_number (minor);
292 if (!port) {
293 printk (KERN_WARNING "%s: no associated port!\n", name);
294 kfree (name);
295 return -ENXIO;
296 }
297
298 fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
299 pdev = parport_register_device (port, name, NULL,
300 NULL, pp_irq, fl, pp);
301 parport_put_port (port);
302
303 if (!pdev) {
304 printk (KERN_WARNING "%s: failed to register device!\n", name);
305 kfree (name);
306 return -ENXIO;
307 }
308
309 pp->pdev = pdev;
310 pr_debug("%s: registered pardevice\n", name);
311 return 0;
312}
313
314static enum ieee1284_phase init_phase (int mode)
315{
316 switch (mode & ~(IEEE1284_DEVICEID
317 | IEEE1284_ADDR)) {
318 case IEEE1284_MODE_NIBBLE:
319 case IEEE1284_MODE_BYTE:
320 return IEEE1284_PH_REV_IDLE;
321 }
322 return IEEE1284_PH_FWD_IDLE;
323}
324
325static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
326{
327 unsigned int minor = iminor(file_inode(file));
328 struct pp_struct *pp = file->private_data;
329 struct parport * port;
330 void __user *argp = (void __user *)arg;
331
332 /* First handle the cases that don't take arguments. */
333 switch (cmd) {
334 case PPCLAIM:
335 {
336 struct ieee1284_info *info;
337 int ret;
338
339 if (pp->flags & PP_CLAIMED) {
340 pr_debug(CHRDEV "%x: you've already got it!\n", minor);
341 return -EINVAL;
342 }
343
344 /* Deferred device registration. */
345 if (!pp->pdev) {
346 int err = register_device (minor, pp);
347 if (err) {
348 return err;
349 }
350 }
351
352 ret = parport_claim_or_block (pp->pdev);
353 if (ret < 0)
354 return ret;
355
356 pp->flags |= PP_CLAIMED;
357
358 /* For interrupt-reporting to work, we need to be
359 * informed of each interrupt. */
360 pp_enable_irq (pp);
361
362 /* We may need to fix up the state machine. */
363 info = &pp->pdev->port->ieee1284;
364 pp->saved_state.mode = info->mode;
365 pp->saved_state.phase = info->phase;
366 info->mode = pp->state.mode;
367 info->phase = pp->state.phase;
368 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
369 parport_set_timeout (pp->pdev, pp->default_inactivity);
370
371 return 0;
372 }
373 case PPEXCL:
374 if (pp->pdev) {
375 pr_debug(CHRDEV "%x: too late for PPEXCL; "
376 "already registered\n", minor);
377 if (pp->flags & PP_EXCL)
378 /* But it's not really an error. */
379 return 0;
380 /* There's no chance of making the driver happy. */
381 return -EINVAL;
382 }
383
384 /* Just remember to register the device exclusively
385 * when we finally do the registration. */
386 pp->flags |= PP_EXCL;
387 return 0;
388 case PPSETMODE:
389 {
390 int mode;
391 if (copy_from_user (&mode, argp, sizeof (mode)))
392 return -EFAULT;
393 /* FIXME: validate mode */
394 pp->state.mode = mode;
395 pp->state.phase = init_phase (mode);
396
397 if (pp->flags & PP_CLAIMED) {
398 pp->pdev->port->ieee1284.mode = mode;
399 pp->pdev->port->ieee1284.phase = pp->state.phase;
400 }
401
402 return 0;
403 }
404 case PPGETMODE:
405 {
406 int mode;
407
408 if (pp->flags & PP_CLAIMED) {
409 mode = pp->pdev->port->ieee1284.mode;
410 } else {
411 mode = pp->state.mode;
412 }
413 if (copy_to_user (argp, &mode, sizeof (mode))) {
414 return -EFAULT;
415 }
416 return 0;
417 }
418 case PPSETPHASE:
419 {
420 int phase;
421 if (copy_from_user (&phase, argp, sizeof (phase))) {
422 return -EFAULT;
423 }
424 /* FIXME: validate phase */
425 pp->state.phase = phase;
426
427 if (pp->flags & PP_CLAIMED) {
428 pp->pdev->port->ieee1284.phase = phase;
429 }
430
431 return 0;
432 }
433 case PPGETPHASE:
434 {
435 int phase;
436
437 if (pp->flags & PP_CLAIMED) {
438 phase = pp->pdev->port->ieee1284.phase;
439 } else {
440 phase = pp->state.phase;
441 }
442 if (copy_to_user (argp, &phase, sizeof (phase))) {
443 return -EFAULT;
444 }
445 return 0;
446 }
447 case PPGETMODES:
448 {
449 unsigned int modes;
450
451 port = parport_find_number (minor);
452 if (!port)
453 return -ENODEV;
454
455 modes = port->modes;
456 parport_put_port(port);
457 if (copy_to_user (argp, &modes, sizeof (modes))) {
458 return -EFAULT;
459 }
460 return 0;
461 }
462 case PPSETFLAGS:
463 {
464 int uflags;
465
466 if (copy_from_user (&uflags, argp, sizeof (uflags))) {
467 return -EFAULT;
468 }
469 pp->flags &= ~PP_FLAGMASK;
470 pp->flags |= (uflags & PP_FLAGMASK);
471 return 0;
472 }
473 case PPGETFLAGS:
474 {
475 int uflags;
476
477 uflags = pp->flags & PP_FLAGMASK;
478 if (copy_to_user (argp, &uflags, sizeof (uflags))) {
479 return -EFAULT;
480 }
481 return 0;
482 }
483 } /* end switch() */
484
485 /* Everything else requires the port to be claimed, so check
486 * that now. */
487 if ((pp->flags & PP_CLAIMED) == 0) {
488 pr_debug(CHRDEV "%x: claim the port first\n", minor);
489 return -EINVAL;
490 }
491
492 port = pp->pdev->port;
493 switch (cmd) {
494 struct ieee1284_info *info;
495 unsigned char reg;
496 unsigned char mask;
497 int mode;
498 int ret;
499 struct timeval par_timeout;
500 long to_jiffies;
501
502 case PPRSTATUS:
503 reg = parport_read_status (port);
504 if (copy_to_user (argp, ®, sizeof (reg)))
505 return -EFAULT;
506 return 0;
507 case PPRDATA:
508 reg = parport_read_data (port);
509 if (copy_to_user (argp, ®, sizeof (reg)))
510 return -EFAULT;
511 return 0;
512 case PPRCONTROL:
513 reg = parport_read_control (port);
514 if (copy_to_user (argp, ®, sizeof (reg)))
515 return -EFAULT;
516 return 0;
517 case PPYIELD:
518 parport_yield_blocking (pp->pdev);
519 return 0;
520
521 case PPRELEASE:
522 /* Save the state machine's state. */
523 info = &pp->pdev->port->ieee1284;
524 pp->state.mode = info->mode;
525 pp->state.phase = info->phase;
526 info->mode = pp->saved_state.mode;
527 info->phase = pp->saved_state.phase;
528 parport_release (pp->pdev);
529 pp->flags &= ~PP_CLAIMED;
530 return 0;
531
532 case PPWCONTROL:
533 if (copy_from_user (®, argp, sizeof (reg)))
534 return -EFAULT;
535 parport_write_control (port, reg);
536 return 0;
537
538 case PPWDATA:
539 if (copy_from_user (®, argp, sizeof (reg)))
540 return -EFAULT;
541 parport_write_data (port, reg);
542 return 0;
543
544 case PPFCONTROL:
545 if (copy_from_user (&mask, argp,
546 sizeof (mask)))
547 return -EFAULT;
548 if (copy_from_user (®, 1 + (unsigned char __user *) arg,
549 sizeof (reg)))
550 return -EFAULT;
551 parport_frob_control (port, mask, reg);
552 return 0;
553
554 case PPDATADIR:
555 if (copy_from_user (&mode, argp, sizeof (mode)))
556 return -EFAULT;
557 if (mode)
558 port->ops->data_reverse (port);
559 else
560 port->ops->data_forward (port);
561 return 0;
562
563 case PPNEGOT:
564 if (copy_from_user (&mode, argp, sizeof (mode)))
565 return -EFAULT;
566 switch ((ret = parport_negotiate (port, mode))) {
567 case 0: break;
568 case -1: /* handshake failed, peripheral not IEEE 1284 */
569 ret = -EIO;
570 break;
571 case 1: /* handshake succeeded, peripheral rejected mode */
572 ret = -ENXIO;
573 break;
574 }
575 pp_enable_irq (pp);
576 return ret;
577
578 case PPWCTLONIRQ:
579 if (copy_from_user (®, argp, sizeof (reg)))
580 return -EFAULT;
581
582 /* Remember what to set the control lines to, for next
583 * time we get an interrupt. */
584 pp->irqctl = reg;
585 pp->irqresponse = 1;
586 return 0;
587
588 case PPCLRIRQ:
589 ret = atomic_read (&pp->irqc);
590 if (copy_to_user (argp, &ret, sizeof (ret)))
591 return -EFAULT;
592 atomic_sub (ret, &pp->irqc);
593 return 0;
594
595 case PPSETTIME:
596 if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
597 return -EFAULT;
598 }
599 /* Convert to jiffies, place in pp->pdev->timeout */
600 if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
601 return -EINVAL;
602 }
603 to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
604 to_jiffies += par_timeout.tv_sec * (long)HZ;
605 if (to_jiffies <= 0) {
606 return -EINVAL;
607 }
608 pp->pdev->timeout = to_jiffies;
609 return 0;
610
611 case PPGETTIME:
612 to_jiffies = pp->pdev->timeout;
613 memset(&par_timeout, 0, sizeof(par_timeout));
614 par_timeout.tv_sec = to_jiffies / HZ;
615 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
616 if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
617 return -EFAULT;
618 return 0;
619
620 default:
621 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
622 return -EINVAL;
623 }
624
625 /* Keep the compiler happy */
626 return 0;
627}
628
629static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
630{
631 long ret;
632 mutex_lock(&pp_do_mutex);
633 ret = pp_do_ioctl(file, cmd, arg);
634 mutex_unlock(&pp_do_mutex);
635 return ret;
636}
637
638static 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
667static 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 pr_debug(CHRDEV "%x: negotiated back to compatibility "
694 "mode because user-space forgot\n", minor);
695 }
696
697 if (pp->flags & PP_CLAIMED) {
698 struct ieee1284_info *info;
699
700 info = &pp->pdev->port->ieee1284;
701 pp->state.mode = info->mode;
702 pp->state.phase = info->phase;
703 info->mode = pp->saved_state.mode;
704 info->phase = pp->saved_state.phase;
705 parport_release (pp->pdev);
706 if (compat_negot != 1) {
707 pr_debug(CHRDEV "%x: released pardevice "
708 "because user-space forgot\n", minor);
709 }
710 }
711
712 if (pp->pdev) {
713 const char *name = pp->pdev->name;
714 parport_unregister_device (pp->pdev);
715 kfree (name);
716 pp->pdev = NULL;
717 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
718 }
719
720 kfree (pp);
721
722 return 0;
723}
724
725/* No kernel lock held - fine */
726static 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
738static struct class *ppdev_class;
739
740static 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 .unlocked_ioctl = pp_ioctl,
747 .open = pp_open,
748 .release = pp_release,
749};
750
751static void pp_attach(struct parport *port)
752{
753 device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
754 NULL, "parport%d", port->number);
755}
756
757static void pp_detach(struct parport *port)
758{
759 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
760}
761
762static struct parport_driver pp_driver = {
763 .name = CHRDEV,
764 .attach = pp_attach,
765 .detach = pp_detach,
766};
767
768static 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 err = parport_register_driver(&pp_driver);
783 if (err < 0) {
784 printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
785 goto out_class;
786 }
787
788 printk (KERN_INFO PP_VERSION "\n");
789 goto out;
790
791out_class:
792 class_destroy(ppdev_class);
793out_chrdev:
794 unregister_chrdev(PP_MAJOR, CHRDEV);
795out:
796 return err;
797}
798
799static void __exit ppdev_cleanup (void)
800{
801 /* Clean up all parport stuff */
802 parport_unregister_driver(&pp_driver);
803 class_destroy(ppdev_class);
804 unregister_chrdev (PP_MAJOR, CHRDEV);
805}
806
807module_init(ppdev_init);
808module_exit(ppdev_cleanup);
809
810MODULE_LICENSE("GPL");
811MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);