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
73 struct 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? */
87 static struct device *devices[PARPORT_MAX];
88
89 static 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
100 static 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
pp_enable_irq(struct pp_struct * pp)108 static 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
pp_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)115 static 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
pp_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)193 static 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
pp_irq(void * private)270 static void pp_irq(void *private)
271 {
272 struct pp_struct *pp = private;
273
274 if (pp->irqresponse) {
275 parport_write_control(pp->pdev->port, pp->irqctl);
276 pp->irqresponse = 0;
277 }
278
279 atomic_inc(&pp->irqc);
280 wake_up_interruptible(&pp->irq_wait);
281 }
282
register_device(int minor,struct pp_struct * pp)283 static int register_device(int minor, struct pp_struct *pp)
284 {
285 struct parport *port;
286 struct pardevice *pdev = NULL;
287 char *name;
288 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");
320 err:
321 kfree(name);
322 return rc;
323 }
324
init_phase(int mode)325 static 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
pp_set_timeout(struct pardevice * pdev,long tv_sec,int tv_usec)336 static 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
pp_do_ioctl(struct file * file,unsigned int cmd,unsigned long arg)352 static 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
359 /* First handle the cases that don't take arguments. */
360 switch (cmd) {
361 case PPCLAIM:
362 {
363 struct ieee1284_info *info;
364 int ret;
365
366 if (pp->flags & PP_CLAIMED) {
367 dev_dbg(&pp->pdev->dev, "you've already got it!\n");
368 return -EINVAL;
369 }
370
371 /* Deferred device registration. */
372 if (!pp->pdev) {
373 int err = register_device(minor, pp);
374
375 if (err)
376 return err;
377 }
378
379 ret = parport_claim_or_block(pp->pdev);
380 if (ret < 0)
381 return ret;
382
383 pp->flags |= PP_CLAIMED;
384
385 /* For interrupt-reporting to work, we need to be
386 * informed of each interrupt. */
387 pp_enable_irq(pp);
388
389 /* We may need to fix up the state machine. */
390 info = &pp->pdev->port->ieee1284;
391 pp->saved_state.mode = info->mode;
392 pp->saved_state.phase = info->phase;
393 info->mode = pp->state.mode;
394 info->phase = pp->state.phase;
395 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
396 parport_set_timeout(pp->pdev, pp->default_inactivity);
397
398 return 0;
399 }
400 case PPEXCL:
401 if (pp->pdev) {
402 dev_dbg(&pp->pdev->dev,
403 "too late for PPEXCL; already registered\n");
404 if (pp->flags & PP_EXCL)
405 /* But it's not really an error. */
406 return 0;
407 /* There's no chance of making the driver happy. */
408 return -EINVAL;
409 }
410
411 /* Just remember to register the device exclusively
412 * when we finally do the registration. */
413 pp->flags |= PP_EXCL;
414 return 0;
415 case PPSETMODE:
416 {
417 int mode;
418
419 if (copy_from_user(&mode, argp, sizeof(mode)))
420 return -EFAULT;
421 /* FIXME: validate mode */
422 pp->state.mode = mode;
423 pp->state.phase = init_phase(mode);
424
425 if (pp->flags & PP_CLAIMED) {
426 pp->pdev->port->ieee1284.mode = mode;
427 pp->pdev->port->ieee1284.phase = pp->state.phase;
428 }
429
430 return 0;
431 }
432 case PPGETMODE:
433 {
434 int mode;
435
436 if (pp->flags & PP_CLAIMED)
437 mode = pp->pdev->port->ieee1284.mode;
438 else
439 mode = pp->state.mode;
440
441 if (copy_to_user(argp, &mode, sizeof(mode)))
442 return -EFAULT;
443 return 0;
444 }
445 case PPSETPHASE:
446 {
447 int phase;
448
449 if (copy_from_user(&phase, argp, sizeof(phase)))
450 return -EFAULT;
451
452 /* FIXME: validate phase */
453 pp->state.phase = phase;
454
455 if (pp->flags & PP_CLAIMED)
456 pp->pdev->port->ieee1284.phase = phase;
457
458 return 0;
459 }
460 case PPGETPHASE:
461 {
462 int phase;
463
464 if (pp->flags & PP_CLAIMED)
465 phase = pp->pdev->port->ieee1284.phase;
466 else
467 phase = pp->state.phase;
468 if (copy_to_user(argp, &phase, sizeof(phase)))
469 return -EFAULT;
470 return 0;
471 }
472 case PPGETMODES:
473 {
474 unsigned int modes;
475
476 port = parport_find_number(minor);
477 if (!port)
478 return -ENODEV;
479
480 modes = port->modes;
481 parport_put_port(port);
482 if (copy_to_user(argp, &modes, sizeof(modes)))
483 return -EFAULT;
484 return 0;
485 }
486 case PPSETFLAGS:
487 {
488 int uflags;
489
490 if (copy_from_user(&uflags, argp, sizeof(uflags)))
491 return -EFAULT;
492 pp->flags &= ~PP_FLAGMASK;
493 pp->flags |= (uflags & PP_FLAGMASK);
494 return 0;
495 }
496 case PPGETFLAGS:
497 {
498 int uflags;
499
500 uflags = pp->flags & PP_FLAGMASK;
501 if (copy_to_user(argp, &uflags, sizeof(uflags)))
502 return -EFAULT;
503 return 0;
504 }
505 } /* end switch() */
506
507 /* Everything else requires the port to be claimed, so check
508 * that now. */
509 if ((pp->flags & PP_CLAIMED) == 0) {
510 pr_debug(CHRDEV "%x: claim the port first\n", minor);
511 return -EINVAL;
512 }
513
514 port = pp->pdev->port;
515 switch (cmd) {
516 struct ieee1284_info *info;
517 unsigned char reg;
518 unsigned char mask;
519 int mode;
520 s32 time32[2];
521 s64 time64[2];
522 struct timespec64 ts;
523 int ret;
524
525 case PPRSTATUS:
526 reg = parport_read_status(port);
527 if (copy_to_user(argp, ®, sizeof(reg)))
528 return -EFAULT;
529 return 0;
530 case PPRDATA:
531 reg = parport_read_data(port);
532 if (copy_to_user(argp, ®, sizeof(reg)))
533 return -EFAULT;
534 return 0;
535 case PPRCONTROL:
536 reg = parport_read_control(port);
537 if (copy_to_user(argp, ®, sizeof(reg)))
538 return -EFAULT;
539 return 0;
540 case PPYIELD:
541 parport_yield_blocking(pp->pdev);
542 return 0;
543
544 case PPRELEASE:
545 /* Save the state machine's state. */
546 info = &pp->pdev->port->ieee1284;
547 pp->state.mode = info->mode;
548 pp->state.phase = info->phase;
549 info->mode = pp->saved_state.mode;
550 info->phase = pp->saved_state.phase;
551 parport_release(pp->pdev);
552 pp->flags &= ~PP_CLAIMED;
553 return 0;
554
555 case PPWCONTROL:
556 if (copy_from_user(®, argp, sizeof(reg)))
557 return -EFAULT;
558 parport_write_control(port, reg);
559 return 0;
560
561 case PPWDATA:
562 if (copy_from_user(®, argp, sizeof(reg)))
563 return -EFAULT;
564 parport_write_data(port, reg);
565 return 0;
566
567 case PPFCONTROL:
568 if (copy_from_user(&mask, argp,
569 sizeof(mask)))
570 return -EFAULT;
571 if (copy_from_user(®, 1 + (unsigned char __user *) arg,
572 sizeof(reg)))
573 return -EFAULT;
574 parport_frob_control(port, mask, reg);
575 return 0;
576
577 case PPDATADIR:
578 if (copy_from_user(&mode, argp, sizeof(mode)))
579 return -EFAULT;
580 if (mode)
581 port->ops->data_reverse(port);
582 else
583 port->ops->data_forward(port);
584 return 0;
585
586 case PPNEGOT:
587 if (copy_from_user(&mode, argp, sizeof(mode)))
588 return -EFAULT;
589 switch ((ret = parport_negotiate(port, mode))) {
590 case 0: break;
591 case -1: /* handshake failed, peripheral not IEEE 1284 */
592 ret = -EIO;
593 break;
594 case 1: /* handshake succeeded, peripheral rejected mode */
595 ret = -ENXIO;
596 break;
597 }
598 pp_enable_irq(pp);
599 return ret;
600
601 case PPWCTLONIRQ:
602 if (copy_from_user(®, argp, sizeof(reg)))
603 return -EFAULT;
604
605 /* Remember what to set the control lines to, for next
606 * time we get an interrupt. */
607 pp->irqctl = reg;
608 pp->irqresponse = 1;
609 return 0;
610
611 case PPCLRIRQ:
612 ret = atomic_read(&pp->irqc);
613 if (copy_to_user(argp, &ret, sizeof(ret)))
614 return -EFAULT;
615 atomic_sub(ret, &pp->irqc);
616 return 0;
617
618 case PPSETTIME32:
619 if (copy_from_user(time32, argp, sizeof(time32)))
620 return -EFAULT;
621
622 if ((time32[0] < 0) || (time32[1] < 0))
623 return -EINVAL;
624
625 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
626
627 case PPSETTIME64:
628 if (copy_from_user(time64, argp, sizeof(time64)))
629 return -EFAULT;
630
631 if ((time64[0] < 0) || (time64[1] < 0))
632 return -EINVAL;
633
634 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
635 time64[1] >>= 32;
636
637 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
638
639 case PPGETTIME32:
640 jiffies_to_timespec64(pp->pdev->timeout, &ts);
641 time32[0] = ts.tv_sec;
642 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
643
644 if (copy_to_user(argp, time32, sizeof(time32)))
645 return -EFAULT;
646
647 return 0;
648
649 case PPGETTIME64:
650 jiffies_to_timespec64(pp->pdev->timeout, &ts);
651 time64[0] = ts.tv_sec;
652 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
653
654 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
655 time64[1] <<= 32;
656
657 if (copy_to_user(argp, time64, sizeof(time64)))
658 return -EFAULT;
659
660 return 0;
661
662 default:
663 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
664 return -EINVAL;
665 }
666
667 /* Keep the compiler happy */
668 return 0;
669 }
670
pp_ioctl(struct file * file,unsigned int cmd,unsigned long arg)671 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
672 {
673 long ret;
674
675 mutex_lock(&pp_do_mutex);
676 ret = pp_do_ioctl(file, cmd, arg);
677 mutex_unlock(&pp_do_mutex);
678 return ret;
679 }
680
681 #ifdef CONFIG_COMPAT
pp_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)682 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
683 unsigned long arg)
684 {
685 return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
686 }
687 #endif
688
pp_open(struct inode * inode,struct file * file)689 static int pp_open(struct inode *inode, struct file *file)
690 {
691 unsigned int minor = iminor(inode);
692 struct pp_struct *pp;
693
694 if (minor >= PARPORT_MAX)
695 return -ENXIO;
696
697 pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
698 if (!pp)
699 return -ENOMEM;
700
701 pp->state.mode = IEEE1284_MODE_COMPAT;
702 pp->state.phase = init_phase(pp->state.mode);
703 pp->flags = 0;
704 pp->irqresponse = 0;
705 atomic_set(&pp->irqc, 0);
706 init_waitqueue_head(&pp->irq_wait);
707
708 /* Defer the actual device registration until the first claim.
709 * That way, we know whether or not the driver wants to have
710 * exclusive access to the port (PPEXCL).
711 */
712 pp->pdev = NULL;
713 file->private_data = pp;
714
715 return 0;
716 }
717
pp_release(struct inode * inode,struct file * file)718 static int pp_release(struct inode *inode, struct file *file)
719 {
720 unsigned int minor = iminor(inode);
721 struct pp_struct *pp = file->private_data;
722 int compat_negot;
723
724 compat_negot = 0;
725 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
726 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
727 struct ieee1284_info *info;
728
729 /* parport released, but not in compatibility mode */
730 parport_claim_or_block(pp->pdev);
731 pp->flags |= PP_CLAIMED;
732 info = &pp->pdev->port->ieee1284;
733 pp->saved_state.mode = info->mode;
734 pp->saved_state.phase = info->phase;
735 info->mode = pp->state.mode;
736 info->phase = pp->state.phase;
737 compat_negot = 1;
738 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
739 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
740 compat_negot = 2;
741 }
742 if (compat_negot) {
743 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
744 dev_dbg(&pp->pdev->dev,
745 "negotiated back to compatibility mode because user-space forgot\n");
746 }
747
748 if ((pp->flags & PP_CLAIMED) && pp->pdev) {
749 struct ieee1284_info *info;
750
751 info = &pp->pdev->port->ieee1284;
752 pp->state.mode = info->mode;
753 pp->state.phase = info->phase;
754 info->mode = pp->saved_state.mode;
755 info->phase = pp->saved_state.phase;
756 parport_release(pp->pdev);
757 if (compat_negot != 1) {
758 pr_debug(CHRDEV "%x: released pardevice "
759 "because user-space forgot\n", minor);
760 }
761 }
762
763 if (pp->pdev) {
764 parport_unregister_device(pp->pdev);
765 ida_simple_remove(&ida_index, pp->index);
766 pp->pdev = NULL;
767 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
768 }
769
770 kfree(pp);
771
772 return 0;
773 }
774
775 /* No kernel lock held - fine */
pp_poll(struct file * file,poll_table * wait)776 static __poll_t pp_poll(struct file *file, poll_table *wait)
777 {
778 struct pp_struct *pp = file->private_data;
779 __poll_t mask = 0;
780
781 poll_wait(file, &pp->irq_wait, wait);
782 if (atomic_read(&pp->irqc))
783 mask |= EPOLLIN | EPOLLRDNORM;
784
785 return mask;
786 }
787
788 static struct class *ppdev_class;
789
790 static const struct file_operations pp_fops = {
791 .owner = THIS_MODULE,
792 .llseek = no_llseek,
793 .read = pp_read,
794 .write = pp_write,
795 .poll = pp_poll,
796 .unlocked_ioctl = pp_ioctl,
797 #ifdef CONFIG_COMPAT
798 .compat_ioctl = pp_compat_ioctl,
799 #endif
800 .open = pp_open,
801 .release = pp_release,
802 };
803
pp_attach(struct parport * port)804 static void pp_attach(struct parport *port)
805 {
806 struct device *ret;
807
808 if (devices[port->number])
809 return;
810
811 ret = device_create(ppdev_class, port->dev,
812 MKDEV(PP_MAJOR, port->number), NULL,
813 "parport%d", port->number);
814 if (IS_ERR(ret)) {
815 pr_err("Failed to create device parport%d\n",
816 port->number);
817 return;
818 }
819 devices[port->number] = ret;
820 }
821
pp_detach(struct parport * port)822 static void pp_detach(struct parport *port)
823 {
824 if (!devices[port->number])
825 return;
826
827 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
828 devices[port->number] = NULL;
829 }
830
pp_probe(struct pardevice * par_dev)831 static int pp_probe(struct pardevice *par_dev)
832 {
833 struct device_driver *drv = par_dev->dev.driver;
834 int len = strlen(drv->name);
835
836 if (strncmp(par_dev->name, drv->name, len))
837 return -ENODEV;
838
839 return 0;
840 }
841
842 static struct parport_driver pp_driver = {
843 .name = CHRDEV,
844 .probe = pp_probe,
845 .match_port = pp_attach,
846 .detach = pp_detach,
847 .devmodel = true,
848 };
849
ppdev_init(void)850 static int __init ppdev_init(void)
851 {
852 int err = 0;
853
854 if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
855 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
856 return -EIO;
857 }
858 ppdev_class = class_create(THIS_MODULE, CHRDEV);
859 if (IS_ERR(ppdev_class)) {
860 err = PTR_ERR(ppdev_class);
861 goto out_chrdev;
862 }
863 err = parport_register_driver(&pp_driver);
864 if (err < 0) {
865 pr_warn(CHRDEV ": unable to register with parport\n");
866 goto out_class;
867 }
868
869 pr_info(PP_VERSION "\n");
870 goto out;
871
872 out_class:
873 class_destroy(ppdev_class);
874 out_chrdev:
875 unregister_chrdev(PP_MAJOR, CHRDEV);
876 out:
877 return err;
878 }
879
ppdev_cleanup(void)880 static void __exit ppdev_cleanup(void)
881 {
882 /* Clean up all parport stuff */
883 parport_unregister_driver(&pp_driver);
884 class_destroy(ppdev_class);
885 unregister_chrdev(PP_MAJOR, CHRDEV);
886 }
887
888 module_init(ppdev_init);
889 module_exit(ppdev_cleanup);
890
891 MODULE_LICENSE("GPL");
892 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
893