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/signal.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 #include <linux/compat.h>
73
74 #define PP_VERSION "ppdev: user-space parallel port driver"
75 #define CHRDEV "ppdev"
76
77 struct pp_struct {
78 struct pardevice *pdev;
79 wait_queue_head_t irq_wait;
80 atomic_t irqc;
81 unsigned int flags;
82 int irqresponse;
83 unsigned char irqctl;
84 struct ieee1284_info state;
85 struct ieee1284_info saved_state;
86 long default_inactivity;
87 int index;
88 };
89
90 /* should we use PARDEVICE_MAX here? */
91 static struct device *devices[PARPORT_MAX];
92
93 static DEFINE_IDA(ida_index);
94
95 /* pp_struct.flags bitfields */
96 #define PP_CLAIMED (1<<0)
97 #define PP_EXCL (1<<1)
98
99 /* Other constants */
100 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
101 #define PP_BUFFER_SIZE 1024
102 #define PARDEVICE_MAX 8
103
104 static DEFINE_MUTEX(pp_do_mutex);
105
106 /* define fixed sized ioctl cmd for y2038 migration */
107 #define PPGETTIME32 _IOR(PP_IOCTL, 0x95, s32[2])
108 #define PPSETTIME32 _IOW(PP_IOCTL, 0x96, s32[2])
109 #define PPGETTIME64 _IOR(PP_IOCTL, 0x95, s64[2])
110 #define PPSETTIME64 _IOW(PP_IOCTL, 0x96, s64[2])
111
pp_enable_irq(struct pp_struct * pp)112 static inline void pp_enable_irq(struct pp_struct *pp)
113 {
114 struct parport *port = pp->pdev->port;
115
116 port->ops->enable_irq(port);
117 }
118
pp_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)119 static ssize_t pp_read(struct file *file, char __user *buf, size_t count,
120 loff_t *ppos)
121 {
122 unsigned int minor = iminor(file_inode(file));
123 struct pp_struct *pp = file->private_data;
124 char *kbuffer;
125 ssize_t bytes_read = 0;
126 struct parport *pport;
127 int mode;
128
129 if (!(pp->flags & PP_CLAIMED)) {
130 /* Don't have the port claimed */
131 pr_debug(CHRDEV "%x: claim the port first\n", minor);
132 return -EINVAL;
133 }
134
135 /* Trivial case. */
136 if (count == 0)
137 return 0;
138
139 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
140 if (!kbuffer)
141 return -ENOMEM;
142 pport = pp->pdev->port;
143 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
144
145 parport_set_timeout(pp->pdev,
146 (file->f_flags & O_NONBLOCK) ?
147 PARPORT_INACTIVITY_O_NONBLOCK :
148 pp->default_inactivity);
149
150 while (bytes_read == 0) {
151 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
152
153 if (mode == IEEE1284_MODE_EPP) {
154 /* various specials for EPP mode */
155 int flags = 0;
156 size_t (*fn)(struct parport *, void *, size_t, int);
157
158 if (pp->flags & PP_W91284PIC)
159 flags |= PARPORT_W91284PIC;
160 if (pp->flags & PP_FASTREAD)
161 flags |= PARPORT_EPP_FAST;
162 if (pport->ieee1284.mode & IEEE1284_ADDR)
163 fn = pport->ops->epp_read_addr;
164 else
165 fn = pport->ops->epp_read_data;
166 bytes_read = (*fn)(pport, kbuffer, need, flags);
167 } else {
168 bytes_read = parport_read(pport, kbuffer, need);
169 }
170
171 if (bytes_read != 0)
172 break;
173
174 if (file->f_flags & O_NONBLOCK) {
175 bytes_read = -EAGAIN;
176 break;
177 }
178
179 if (signal_pending(current)) {
180 bytes_read = -ERESTARTSYS;
181 break;
182 }
183
184 cond_resched();
185 }
186
187 parport_set_timeout(pp->pdev, pp->default_inactivity);
188
189 if (bytes_read > 0 && copy_to_user(buf, kbuffer, bytes_read))
190 bytes_read = -EFAULT;
191
192 kfree(kbuffer);
193 pp_enable_irq(pp);
194 return bytes_read;
195 }
196
pp_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)197 static ssize_t pp_write(struct file *file, const char __user *buf,
198 size_t count, loff_t *ppos)
199 {
200 unsigned int minor = iminor(file_inode(file));
201 struct pp_struct *pp = file->private_data;
202 char *kbuffer;
203 ssize_t bytes_written = 0;
204 ssize_t wrote;
205 int mode;
206 struct parport *pport;
207
208 if (!(pp->flags & PP_CLAIMED)) {
209 /* Don't have the port claimed */
210 pr_debug(CHRDEV "%x: claim the port first\n", minor);
211 return -EINVAL;
212 }
213
214 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
215 if (!kbuffer)
216 return -ENOMEM;
217
218 pport = pp->pdev->port;
219 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
220
221 parport_set_timeout(pp->pdev,
222 (file->f_flags & O_NONBLOCK) ?
223 PARPORT_INACTIVITY_O_NONBLOCK :
224 pp->default_inactivity);
225
226 while (bytes_written < count) {
227 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
228
229 if (copy_from_user(kbuffer, buf + bytes_written, n)) {
230 bytes_written = -EFAULT;
231 break;
232 }
233
234 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
235 /* do a fast EPP write */
236 if (pport->ieee1284.mode & IEEE1284_ADDR) {
237 wrote = pport->ops->epp_write_addr(pport,
238 kbuffer, n, PARPORT_EPP_FAST);
239 } else {
240 wrote = pport->ops->epp_write_data(pport,
241 kbuffer, n, PARPORT_EPP_FAST);
242 }
243 } else {
244 wrote = parport_write(pp->pdev->port, kbuffer, n);
245 }
246
247 if (wrote <= 0) {
248 if (!bytes_written)
249 bytes_written = wrote;
250 break;
251 }
252
253 bytes_written += wrote;
254
255 if (file->f_flags & O_NONBLOCK) {
256 if (!bytes_written)
257 bytes_written = -EAGAIN;
258 break;
259 }
260
261 if (signal_pending(current))
262 break;
263
264 cond_resched();
265 }
266
267 parport_set_timeout(pp->pdev, pp->default_inactivity);
268
269 kfree(kbuffer);
270 pp_enable_irq(pp);
271 return bytes_written;
272 }
273
pp_irq(void * private)274 static void pp_irq(void *private)
275 {
276 struct pp_struct *pp = private;
277
278 if (pp->irqresponse) {
279 parport_write_control(pp->pdev->port, pp->irqctl);
280 pp->irqresponse = 0;
281 }
282
283 atomic_inc(&pp->irqc);
284 wake_up_interruptible(&pp->irq_wait);
285 }
286
register_device(int minor,struct pp_struct * pp)287 static int register_device(int minor, struct pp_struct *pp)
288 {
289 struct parport *port;
290 struct pardevice *pdev = NULL;
291 char *name;
292 struct pardev_cb ppdev_cb;
293 int rc = 0, index;
294
295 name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
296 if (name == NULL)
297 return -ENOMEM;
298
299 port = parport_find_number(minor);
300 if (!port) {
301 pr_warn("%s: no associated port!\n", name);
302 rc = -ENXIO;
303 goto err;
304 }
305
306 index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
307 memset(&ppdev_cb, 0, sizeof(ppdev_cb));
308 ppdev_cb.irq_func = pp_irq;
309 ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
310 ppdev_cb.private = pp;
311 pdev = parport_register_dev_model(port, name, &ppdev_cb, index);
312 parport_put_port(port);
313
314 if (!pdev) {
315 pr_warn("%s: failed to register device!\n", name);
316 rc = -ENXIO;
317 ida_simple_remove(&ida_index, index);
318 goto err;
319 }
320
321 pp->pdev = pdev;
322 pp->index = index;
323 dev_dbg(&pdev->dev, "registered pardevice\n");
324 err:
325 kfree(name);
326 return rc;
327 }
328
init_phase(int mode)329 static enum ieee1284_phase init_phase(int mode)
330 {
331 switch (mode & ~(IEEE1284_DEVICEID
332 | IEEE1284_ADDR)) {
333 case IEEE1284_MODE_NIBBLE:
334 case IEEE1284_MODE_BYTE:
335 return IEEE1284_PH_REV_IDLE;
336 }
337 return IEEE1284_PH_FWD_IDLE;
338 }
339
pp_set_timeout(struct pardevice * pdev,long tv_sec,int tv_usec)340 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
341 {
342 long to_jiffies;
343
344 if ((tv_sec < 0) || (tv_usec < 0))
345 return -EINVAL;
346
347 to_jiffies = usecs_to_jiffies(tv_usec);
348 to_jiffies += tv_sec * HZ;
349 if (to_jiffies <= 0)
350 return -EINVAL;
351
352 pdev->timeout = to_jiffies;
353 return 0;
354 }
355
pp_do_ioctl(struct file * file,unsigned int cmd,unsigned long arg)356 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
357 {
358 unsigned int minor = iminor(file_inode(file));
359 struct pp_struct *pp = file->private_data;
360 struct parport *port;
361 void __user *argp = (void __user *)arg;
362
363 /* First handle the cases that don't take arguments. */
364 switch (cmd) {
365 case PPCLAIM:
366 {
367 struct ieee1284_info *info;
368 int ret;
369
370 if (pp->flags & PP_CLAIMED) {
371 dev_dbg(&pp->pdev->dev, "you've already got it!\n");
372 return -EINVAL;
373 }
374
375 /* Deferred device registration. */
376 if (!pp->pdev) {
377 int err = register_device(minor, pp);
378
379 if (err)
380 return err;
381 }
382
383 ret = parport_claim_or_block(pp->pdev);
384 if (ret < 0)
385 return ret;
386
387 pp->flags |= PP_CLAIMED;
388
389 /* For interrupt-reporting to work, we need to be
390 * informed of each interrupt. */
391 pp_enable_irq(pp);
392
393 /* We may need to fix up the state machine. */
394 info = &pp->pdev->port->ieee1284;
395 pp->saved_state.mode = info->mode;
396 pp->saved_state.phase = info->phase;
397 info->mode = pp->state.mode;
398 info->phase = pp->state.phase;
399 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
400 parport_set_timeout(pp->pdev, pp->default_inactivity);
401
402 return 0;
403 }
404 case PPEXCL:
405 if (pp->pdev) {
406 dev_dbg(&pp->pdev->dev,
407 "too late for PPEXCL; already registered\n");
408 if (pp->flags & PP_EXCL)
409 /* But it's not really an error. */
410 return 0;
411 /* There's no chance of making the driver happy. */
412 return -EINVAL;
413 }
414
415 /* Just remember to register the device exclusively
416 * when we finally do the registration. */
417 pp->flags |= PP_EXCL;
418 return 0;
419 case PPSETMODE:
420 {
421 int mode;
422
423 if (copy_from_user(&mode, argp, sizeof(mode)))
424 return -EFAULT;
425 /* FIXME: validate mode */
426 pp->state.mode = mode;
427 pp->state.phase = init_phase(mode);
428
429 if (pp->flags & PP_CLAIMED) {
430 pp->pdev->port->ieee1284.mode = mode;
431 pp->pdev->port->ieee1284.phase = pp->state.phase;
432 }
433
434 return 0;
435 }
436 case PPGETMODE:
437 {
438 int mode;
439
440 if (pp->flags & PP_CLAIMED)
441 mode = pp->pdev->port->ieee1284.mode;
442 else
443 mode = pp->state.mode;
444
445 if (copy_to_user(argp, &mode, sizeof(mode)))
446 return -EFAULT;
447 return 0;
448 }
449 case PPSETPHASE:
450 {
451 int phase;
452
453 if (copy_from_user(&phase, argp, sizeof(phase)))
454 return -EFAULT;
455
456 /* FIXME: validate phase */
457 pp->state.phase = phase;
458
459 if (pp->flags & PP_CLAIMED)
460 pp->pdev->port->ieee1284.phase = phase;
461
462 return 0;
463 }
464 case PPGETPHASE:
465 {
466 int phase;
467
468 if (pp->flags & PP_CLAIMED)
469 phase = pp->pdev->port->ieee1284.phase;
470 else
471 phase = pp->state.phase;
472 if (copy_to_user(argp, &phase, sizeof(phase)))
473 return -EFAULT;
474 return 0;
475 }
476 case PPGETMODES:
477 {
478 unsigned int modes;
479
480 port = parport_find_number(minor);
481 if (!port)
482 return -ENODEV;
483
484 modes = port->modes;
485 parport_put_port(port);
486 if (copy_to_user(argp, &modes, sizeof(modes)))
487 return -EFAULT;
488 return 0;
489 }
490 case PPSETFLAGS:
491 {
492 int uflags;
493
494 if (copy_from_user(&uflags, argp, sizeof(uflags)))
495 return -EFAULT;
496 pp->flags &= ~PP_FLAGMASK;
497 pp->flags |= (uflags & PP_FLAGMASK);
498 return 0;
499 }
500 case PPGETFLAGS:
501 {
502 int uflags;
503
504 uflags = pp->flags & PP_FLAGMASK;
505 if (copy_to_user(argp, &uflags, sizeof(uflags)))
506 return -EFAULT;
507 return 0;
508 }
509 } /* end switch() */
510
511 /* Everything else requires the port to be claimed, so check
512 * that now. */
513 if ((pp->flags & PP_CLAIMED) == 0) {
514 pr_debug(CHRDEV "%x: claim the port first\n", minor);
515 return -EINVAL;
516 }
517
518 port = pp->pdev->port;
519 switch (cmd) {
520 struct ieee1284_info *info;
521 unsigned char reg;
522 unsigned char mask;
523 int mode;
524 s32 time32[2];
525 s64 time64[2];
526 struct timespec64 ts;
527 int ret;
528
529 case PPRSTATUS:
530 reg = parport_read_status(port);
531 if (copy_to_user(argp, ®, sizeof(reg)))
532 return -EFAULT;
533 return 0;
534 case PPRDATA:
535 reg = parport_read_data(port);
536 if (copy_to_user(argp, ®, sizeof(reg)))
537 return -EFAULT;
538 return 0;
539 case PPRCONTROL:
540 reg = parport_read_control(port);
541 if (copy_to_user(argp, ®, sizeof(reg)))
542 return -EFAULT;
543 return 0;
544 case PPYIELD:
545 parport_yield_blocking(pp->pdev);
546 return 0;
547
548 case PPRELEASE:
549 /* Save the state machine's state. */
550 info = &pp->pdev->port->ieee1284;
551 pp->state.mode = info->mode;
552 pp->state.phase = info->phase;
553 info->mode = pp->saved_state.mode;
554 info->phase = pp->saved_state.phase;
555 parport_release(pp->pdev);
556 pp->flags &= ~PP_CLAIMED;
557 return 0;
558
559 case PPWCONTROL:
560 if (copy_from_user(®, argp, sizeof(reg)))
561 return -EFAULT;
562 parport_write_control(port, reg);
563 return 0;
564
565 case PPWDATA:
566 if (copy_from_user(®, argp, sizeof(reg)))
567 return -EFAULT;
568 parport_write_data(port, reg);
569 return 0;
570
571 case PPFCONTROL:
572 if (copy_from_user(&mask, argp,
573 sizeof(mask)))
574 return -EFAULT;
575 if (copy_from_user(®, 1 + (unsigned char __user *) arg,
576 sizeof(reg)))
577 return -EFAULT;
578 parport_frob_control(port, mask, reg);
579 return 0;
580
581 case PPDATADIR:
582 if (copy_from_user(&mode, argp, sizeof(mode)))
583 return -EFAULT;
584 if (mode)
585 port->ops->data_reverse(port);
586 else
587 port->ops->data_forward(port);
588 return 0;
589
590 case PPNEGOT:
591 if (copy_from_user(&mode, argp, sizeof(mode)))
592 return -EFAULT;
593 switch ((ret = parport_negotiate(port, mode))) {
594 case 0: break;
595 case -1: /* handshake failed, peripheral not IEEE 1284 */
596 ret = -EIO;
597 break;
598 case 1: /* handshake succeeded, peripheral rejected mode */
599 ret = -ENXIO;
600 break;
601 }
602 pp_enable_irq(pp);
603 return ret;
604
605 case PPWCTLONIRQ:
606 if (copy_from_user(®, argp, sizeof(reg)))
607 return -EFAULT;
608
609 /* Remember what to set the control lines to, for next
610 * time we get an interrupt. */
611 pp->irqctl = reg;
612 pp->irqresponse = 1;
613 return 0;
614
615 case PPCLRIRQ:
616 ret = atomic_read(&pp->irqc);
617 if (copy_to_user(argp, &ret, sizeof(ret)))
618 return -EFAULT;
619 atomic_sub(ret, &pp->irqc);
620 return 0;
621
622 case PPSETTIME32:
623 if (copy_from_user(time32, argp, sizeof(time32)))
624 return -EFAULT;
625
626 if ((time32[0] < 0) || (time32[1] < 0))
627 return -EINVAL;
628
629 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
630
631 case PPSETTIME64:
632 if (copy_from_user(time64, argp, sizeof(time64)))
633 return -EFAULT;
634
635 if ((time64[0] < 0) || (time64[1] < 0))
636 return -EINVAL;
637
638 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
639 time64[1] >>= 32;
640
641 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
642
643 case PPGETTIME32:
644 jiffies_to_timespec64(pp->pdev->timeout, &ts);
645 time32[0] = ts.tv_sec;
646 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
647
648 if (copy_to_user(argp, time32, sizeof(time32)))
649 return -EFAULT;
650
651 return 0;
652
653 case PPGETTIME64:
654 jiffies_to_timespec64(pp->pdev->timeout, &ts);
655 time64[0] = ts.tv_sec;
656 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
657
658 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
659 time64[1] <<= 32;
660
661 if (copy_to_user(argp, time64, sizeof(time64)))
662 return -EFAULT;
663
664 return 0;
665
666 default:
667 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
668 return -EINVAL;
669 }
670
671 /* Keep the compiler happy */
672 return 0;
673 }
674
pp_ioctl(struct file * file,unsigned int cmd,unsigned long arg)675 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
676 {
677 long ret;
678
679 mutex_lock(&pp_do_mutex);
680 ret = pp_do_ioctl(file, cmd, arg);
681 mutex_unlock(&pp_do_mutex);
682 return ret;
683 }
684
685 #ifdef CONFIG_COMPAT
pp_compat_ioctl(struct file * file,unsigned int cmd,unsigned long arg)686 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
687 unsigned long arg)
688 {
689 return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
690 }
691 #endif
692
pp_open(struct inode * inode,struct file * file)693 static int pp_open(struct inode *inode, struct file *file)
694 {
695 unsigned int minor = iminor(inode);
696 struct pp_struct *pp;
697
698 if (minor >= PARPORT_MAX)
699 return -ENXIO;
700
701 pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
702 if (!pp)
703 return -ENOMEM;
704
705 pp->state.mode = IEEE1284_MODE_COMPAT;
706 pp->state.phase = init_phase(pp->state.mode);
707 pp->flags = 0;
708 pp->irqresponse = 0;
709 atomic_set(&pp->irqc, 0);
710 init_waitqueue_head(&pp->irq_wait);
711
712 /* Defer the actual device registration until the first claim.
713 * That way, we know whether or not the driver wants to have
714 * exclusive access to the port (PPEXCL).
715 */
716 pp->pdev = NULL;
717 file->private_data = pp;
718
719 return 0;
720 }
721
pp_release(struct inode * inode,struct file * file)722 static int pp_release(struct inode *inode, struct file *file)
723 {
724 unsigned int minor = iminor(inode);
725 struct pp_struct *pp = file->private_data;
726 int compat_negot;
727
728 compat_negot = 0;
729 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
730 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
731 struct ieee1284_info *info;
732
733 /* parport released, but not in compatibility mode */
734 parport_claim_or_block(pp->pdev);
735 pp->flags |= PP_CLAIMED;
736 info = &pp->pdev->port->ieee1284;
737 pp->saved_state.mode = info->mode;
738 pp->saved_state.phase = info->phase;
739 info->mode = pp->state.mode;
740 info->phase = pp->state.phase;
741 compat_negot = 1;
742 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
743 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
744 compat_negot = 2;
745 }
746 if (compat_negot) {
747 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
748 dev_dbg(&pp->pdev->dev,
749 "negotiated back to compatibility mode because user-space forgot\n");
750 }
751
752 if (pp->flags & PP_CLAIMED) {
753 struct ieee1284_info *info;
754
755 info = &pp->pdev->port->ieee1284;
756 pp->state.mode = info->mode;
757 pp->state.phase = info->phase;
758 info->mode = pp->saved_state.mode;
759 info->phase = pp->saved_state.phase;
760 parport_release(pp->pdev);
761 if (compat_negot != 1) {
762 pr_debug(CHRDEV "%x: released pardevice "
763 "because user-space forgot\n", minor);
764 }
765 }
766
767 if (pp->pdev) {
768 parport_unregister_device(pp->pdev);
769 ida_simple_remove(&ida_index, pp->index);
770 pp->pdev = NULL;
771 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
772 }
773
774 kfree(pp);
775
776 return 0;
777 }
778
779 /* No kernel lock held - fine */
pp_poll(struct file * file,poll_table * wait)780 static __poll_t pp_poll(struct file *file, poll_table *wait)
781 {
782 struct pp_struct *pp = file->private_data;
783 __poll_t mask = 0;
784
785 poll_wait(file, &pp->irq_wait, wait);
786 if (atomic_read(&pp->irqc))
787 mask |= EPOLLIN | EPOLLRDNORM;
788
789 return mask;
790 }
791
792 static struct class *ppdev_class;
793
794 static const struct file_operations pp_fops = {
795 .owner = THIS_MODULE,
796 .llseek = no_llseek,
797 .read = pp_read,
798 .write = pp_write,
799 .poll = pp_poll,
800 .unlocked_ioctl = pp_ioctl,
801 #ifdef CONFIG_COMPAT
802 .compat_ioctl = pp_compat_ioctl,
803 #endif
804 .open = pp_open,
805 .release = pp_release,
806 };
807
pp_attach(struct parport * port)808 static void pp_attach(struct parport *port)
809 {
810 struct device *ret;
811
812 if (devices[port->number])
813 return;
814
815 ret = device_create(ppdev_class, port->dev,
816 MKDEV(PP_MAJOR, port->number), NULL,
817 "parport%d", port->number);
818 if (IS_ERR(ret)) {
819 pr_err("Failed to create device parport%d\n",
820 port->number);
821 return;
822 }
823 devices[port->number] = ret;
824 }
825
pp_detach(struct parport * port)826 static void pp_detach(struct parport *port)
827 {
828 if (!devices[port->number])
829 return;
830
831 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
832 devices[port->number] = NULL;
833 }
834
pp_probe(struct pardevice * par_dev)835 static int pp_probe(struct pardevice *par_dev)
836 {
837 struct device_driver *drv = par_dev->dev.driver;
838 int len = strlen(drv->name);
839
840 if (strncmp(par_dev->name, drv->name, len))
841 return -ENODEV;
842
843 return 0;
844 }
845
846 static struct parport_driver pp_driver = {
847 .name = CHRDEV,
848 .probe = pp_probe,
849 .match_port = pp_attach,
850 .detach = pp_detach,
851 .devmodel = true,
852 };
853
ppdev_init(void)854 static int __init ppdev_init(void)
855 {
856 int err = 0;
857
858 if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
859 pr_warn(CHRDEV ": unable to get major %d\n", PP_MAJOR);
860 return -EIO;
861 }
862 ppdev_class = class_create(THIS_MODULE, CHRDEV);
863 if (IS_ERR(ppdev_class)) {
864 err = PTR_ERR(ppdev_class);
865 goto out_chrdev;
866 }
867 err = parport_register_driver(&pp_driver);
868 if (err < 0) {
869 pr_warn(CHRDEV ": unable to register with parport\n");
870 goto out_class;
871 }
872
873 pr_info(PP_VERSION "\n");
874 goto out;
875
876 out_class:
877 class_destroy(ppdev_class);
878 out_chrdev:
879 unregister_chrdev(PP_MAJOR, CHRDEV);
880 out:
881 return err;
882 }
883
ppdev_cleanup(void)884 static void __exit ppdev_cleanup(void)
885 {
886 /* Clean up all parport stuff */
887 parport_unregister_driver(&pp_driver);
888 class_destroy(ppdev_class);
889 unregister_chrdev(PP_MAJOR, CHRDEV);
890 }
891
892 module_init(ppdev_init);
893 module_exit(ppdev_cleanup);
894
895 MODULE_LICENSE("GPL");
896 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
897