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misc: mic: silence an overflow warning
[linux-block.git] / drivers / char / ppdev.c
CommitLineData
1da177e4
LT		 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>
1da177e4
LT		 63#include <linux/ioctl.h>
64#include <linux/parport.h>
65#include <linux/ctype.h>
66#include <linux/poll.h>
5a0e3ad6 67#include <linux/slab.h>
e6a67846 68#include <linux/major.h>
1da177e4 69#include <linux/ppdev.h>
613655fa 70#include <linux/mutex.h>
6d535d3e 71#include <linux/uaccess.h>
17a3596f 72#include <linux/compat.h>
1da177e4
LT		 73
74#define PP_VERSION "ppdev: user-space parallel port driver"
75#define CHRDEV "ppdev"
76
77struct 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};
88
89/* pp_struct.flags bitfields */
90#define PP_CLAIMED (1<<0)
91#define PP_EXCL (1<<1)
92
93/* Other constants */
94#define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
95#define PP_BUFFER_SIZE 1024
96#define PARDEVICE_MAX 8
97
98/* ROUND_UP macro from fs/select.c */
99#define ROUND_UP(x,y) (((x)+(y)-1)/(y))
100
613655fa 101static DEFINE_MUTEX(pp_do_mutex);
3b9ab374
BJZ		 102
103/* define fixed sized ioctl cmd for y2038 migration */
104#define PPGETTIME32 _IOR(PP_IOCTL, 0x95, s32[2])
105#define PPSETTIME32 _IOW(PP_IOCTL, 0x96, s32[2])
106#define PPGETTIME64 _IOR(PP_IOCTL, 0x95, s64[2])
107#define PPSETTIME64 _IOW(PP_IOCTL, 0x96, s64[2])
108
1da177e4
LT		 109static inline void pp_enable_irq (struct pp_struct *pp)
110{
111 struct parport *port = pp->pdev->port;
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{
496ad9aa 118 unsigned int minor = iminor(file_inode(file));
1da177e4
LT		 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 */
81fc401e 127 pr_debug(CHRDEV "%x: claim the port first\n", minor);
1da177e4
LT		 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 }
139 pport = pp->pdev->port;
140 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
141
142 parport_set_timeout (pp->pdev,
143 (file->f_flags & O_NONBLOCK) ?
144 PARPORT_INACTIVITY_O_NONBLOCK :
145 pp->default_inactivity);
146
147 while (bytes_read == 0) {
148 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
149
150 if (mode == IEEE1284_MODE_EPP) {
151 /* various specials for EPP mode */
152 int flags = 0;
153 size_t (*fn)(struct parport *, void *, size_t, int);
154
155 if (pp->flags & PP_W91284PIC) {
156 flags |= PARPORT_W91284PIC;
157 }
158 if (pp->flags & PP_FASTREAD) {
159 flags |= PARPORT_EPP_FAST;
160 }
161 if (pport->ieee1284.mode & IEEE1284_ADDR) {
162 fn = pport->ops->epp_read_addr;
163 } else {
164 fn = pport->ops->epp_read_data;
165 }
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
197static ssize_t pp_write (struct file * file, const char __user * buf,
198 size_t count, loff_t * ppos)
199{
496ad9aa 200 unsigned int minor = iminor(file_inode(file));
1da177e4
LT		 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 */
81fc401e 210 pr_debug(CHRDEV "%x: claim the port first\n", minor);
1da177e4
LT		 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 }
251 break;
252 }
253
254 bytes_written += wrote;
255
256 if (file->f_flags & O_NONBLOCK) {
257 if (!bytes_written)
258 bytes_written = -EAGAIN;
259 break;
260 }
261
5d0c3d4f 262 if (signal_pending (current))
1da177e4 263 break;
1da177e4
LT		 264
265 cond_resched();
266 }
267
268 parport_set_timeout (pp->pdev, pp->default_inactivity);
269
270 kfree (kbuffer);
271 pp_enable_irq (pp);
272 return bytes_written;
273}
274
5712cb3d 275static void pp_irq (void *private)
1da177e4 276{
5712cb3d 277 struct pp_struct *pp = private;
1da177e4
LT		 278
279 if (pp->irqresponse) {
280 parport_write_control (pp->pdev->port, pp->irqctl);
281 pp->irqresponse = 0;
282 }
283
284 atomic_inc (&pp->irqc);
285 wake_up_interruptible (&pp->irq_wait);
286}
287
288static int register_device (int minor, struct pp_struct *pp)
289{
290 struct parport *port;
291 struct pardevice * pdev = NULL;
292 char *name;
293 int fl;
294
87575437 295 name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
1da177e4
LT		 296 if (name == NULL)
297 return -ENOMEM;
298
1da177e4
LT		 299 port = parport_find_number (minor);
300 if (!port) {
301 printk (KERN_WARNING "%s: no associated port!\n", name);
302 kfree (name);
303 return -ENXIO;
304 }
305
306 fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
307 pdev = parport_register_device (port, name, NULL,
308 NULL, pp_irq, fl, pp);
309 parport_put_port (port);
310
311 if (!pdev) {
312 printk (KERN_WARNING "%s: failed to register device!\n", name);
313 kfree (name);
314 return -ENXIO;
315 }
316
317 pp->pdev = pdev;
81fc401e 318 pr_debug("%s: registered pardevice\n", name);
1da177e4
LT		 319 return 0;
320}
321
322static enum ieee1284_phase init_phase (int mode)
323{
324 switch (mode & ~(IEEE1284_DEVICEID
325 | IEEE1284_ADDR)) {
326 case IEEE1284_MODE_NIBBLE:
327 case IEEE1284_MODE_BYTE:
328 return IEEE1284_PH_REV_IDLE;
329 }
330 return IEEE1284_PH_FWD_IDLE;
331}
332
3b9ab374
BJZ		 333static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
334{
335 long to_jiffies;
336
337 if ((tv_sec < 0) || (tv_usec < 0))
338 return -EINVAL;
339
340 to_jiffies = usecs_to_jiffies(tv_usec);
341 to_jiffies += tv_sec * HZ;
342 if (to_jiffies <= 0)
343 return -EINVAL;
344
345 pdev->timeout = to_jiffies;
346 return 0;
347}
348
6d535d3e 349static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 350{
496ad9aa 351 unsigned int minor = iminor(file_inode(file));
1da177e4
LT		 352 struct pp_struct *pp = file->private_data;
353 struct parport * port;
354 void __user *argp = (void __user *)arg;
355
356 /* First handle the cases that don't take arguments. */
357 switch (cmd) {
358 case PPCLAIM:
359 {
360 struct ieee1284_info *info;
361 int ret;
362
363 if (pp->flags & PP_CLAIMED) {
81fc401e 364 pr_debug(CHRDEV "%x: you've already got it!\n", minor);
1da177e4
LT		 365 return -EINVAL;
366 }
367
368 /* Deferred device registration. */
369 if (!pp->pdev) {
370 int err = register_device (minor, pp);
371 if (err) {
372 return err;
373 }
374 }
375
376 ret = parport_claim_or_block (pp->pdev);
377 if (ret < 0)
378 return ret;
379
380 pp->flags |= PP_CLAIMED;
381
382 /* For interrupt-reporting to work, we need to be
383 * informed of each interrupt. */
384 pp_enable_irq (pp);
385
386 /* We may need to fix up the state machine. */
387 info = &pp->pdev->port->ieee1284;
388 pp->saved_state.mode = info->mode;
389 pp->saved_state.phase = info->phase;
390 info->mode = pp->state.mode;
391 info->phase = pp->state.phase;
392 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
393 parport_set_timeout (pp->pdev, pp->default_inactivity);
394
395 return 0;
396 }
397 case PPEXCL:
398 if (pp->pdev) {
81fc401e 399 pr_debug(CHRDEV "%x: too late for PPEXCL; "
1da177e4
LT		 400 "already registered\n", minor);
401 if (pp->flags & PP_EXCL)
402 /* But it's not really an error. */
403 return 0;
404 /* There's no chance of making the driver happy. */
405 return -EINVAL;
406 }
407
408 /* Just remember to register the device exclusively
409 * when we finally do the registration. */
410 pp->flags |= PP_EXCL;
411 return 0;
412 case PPSETMODE:
413 {
414 int mode;
415 if (copy_from_user (&mode, argp, sizeof (mode)))
416 return -EFAULT;
417 /* FIXME: validate mode */
418 pp->state.mode = mode;
419 pp->state.phase = init_phase (mode);
420
421 if (pp->flags & PP_CLAIMED) {
422 pp->pdev->port->ieee1284.mode = mode;
423 pp->pdev->port->ieee1284.phase = pp->state.phase;
424 }
425
426 return 0;
427 }
428 case PPGETMODE:
429 {
430 int mode;
431
432 if (pp->flags & PP_CLAIMED) {
433 mode = pp->pdev->port->ieee1284.mode;
434 } else {
435 mode = pp->state.mode;
436 }
437 if (copy_to_user (argp, &mode, sizeof (mode))) {
438 return -EFAULT;
439 }
440 return 0;
441 }
442 case PPSETPHASE:
443 {
444 int phase;
445 if (copy_from_user (&phase, argp, sizeof (phase))) {
446 return -EFAULT;
447 }
448 /* FIXME: validate phase */
449 pp->state.phase = phase;
450
451 if (pp->flags & PP_CLAIMED) {
452 pp->pdev->port->ieee1284.phase = phase;
453 }
454
455 return 0;
456 }
457 case PPGETPHASE:
458 {
459 int phase;
460
461 if (pp->flags & PP_CLAIMED) {
462 phase = pp->pdev->port->ieee1284.phase;
463 } else {
464 phase = pp->state.phase;
465 }
466 if (copy_to_user (argp, &phase, sizeof (phase))) {
467 return -EFAULT;
468 }
469 return 0;
470 }
471 case PPGETMODES:
472 {
473 unsigned int modes;
474
475 port = parport_find_number (minor);
476 if (!port)
477 return -ENODEV;
478
479 modes = port->modes;
d98808a2 480 parport_put_port(port);
1da177e4
LT		 481 if (copy_to_user (argp, &modes, sizeof (modes))) {
482 return -EFAULT;
483 }
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 }
493 pp->flags &= ~PP_FLAGMASK;
494 pp->flags |= (uflags & PP_FLAGMASK);
495 return 0;
496 }
497 case PPGETFLAGS:
498 {
499 int uflags;
500
501 uflags = pp->flags & PP_FLAGMASK;
502 if (copy_to_user (argp, &uflags, sizeof (uflags))) {
503 return -EFAULT;
504 }
505 return 0;
506 }
507 } /* end switch() */
508
509 /* Everything else requires the port to be claimed, so check
510 * that now. */
511 if ((pp->flags & PP_CLAIMED) == 0) {
81fc401e 512 pr_debug(CHRDEV "%x: claim the port first\n", minor);
1da177e4
LT		 513 return -EINVAL;
514 }
515
516 port = pp->pdev->port;
517 switch (cmd) {
518 struct ieee1284_info *info;
519 unsigned char reg;
520 unsigned char mask;
521 int mode;
3b9ab374
BJZ		 522 s32 time32[2];
523 s64 time64[2];
524 struct timespec64 ts;
1da177e4 525 int ret;
1da177e4
LT		 526
527 case PPRSTATUS:
528 reg = parport_read_status (port);
529 if (copy_to_user (argp, &reg, sizeof (reg)))
530 return -EFAULT;
531 return 0;
532 case PPRDATA:
533 reg = parport_read_data (port);
534 if (copy_to_user (argp, &reg, sizeof (reg)))
535 return -EFAULT;
536 return 0;
537 case PPRCONTROL:
538 reg = parport_read_control (port);
539 if (copy_to_user (argp, &reg, sizeof (reg)))
540 return -EFAULT;
541 return 0;
542 case PPYIELD:
543 parport_yield_blocking (pp->pdev);
544 return 0;
545
546 case PPRELEASE:
547 /* Save the state machine's state. */
548 info = &pp->pdev->port->ieee1284;
549 pp->state.mode = info->mode;
550 pp->state.phase = info->phase;
551 info->mode = pp->saved_state.mode;
552 info->phase = pp->saved_state.phase;
553 parport_release (pp->pdev);
554 pp->flags &= ~PP_CLAIMED;
555 return 0;
556
557 case PPWCONTROL:
558 if (copy_from_user (&reg, argp, sizeof (reg)))
559 return -EFAULT;
560 parport_write_control (port, reg);
561 return 0;
562
563 case PPWDATA:
564 if (copy_from_user (&reg, argp, sizeof (reg)))
565 return -EFAULT;
566 parport_write_data (port, reg);
567 return 0;
568
569 case PPFCONTROL:
570 if (copy_from_user (&mask, argp,
571 sizeof (mask)))
572 return -EFAULT;
573 if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
574 sizeof (reg)))
575 return -EFAULT;
576 parport_frob_control (port, mask, reg);
577 return 0;
578
579 case PPDATADIR:
580 if (copy_from_user (&mode, argp, sizeof (mode)))
581 return -EFAULT;
582 if (mode)
583 port->ops->data_reverse (port);
584 else
585 port->ops->data_forward (port);
586 return 0;
587
588 case PPNEGOT:
589 if (copy_from_user (&mode, argp, sizeof (mode)))
590 return -EFAULT;
591 switch ((ret = parport_negotiate (port, mode))) {
592 case 0: break;
593 case -1: /* handshake failed, peripheral not IEEE 1284 */
594 ret = -EIO;
595 break;
596 case 1: /* handshake succeeded, peripheral rejected mode */
597 ret = -ENXIO;
598 break;
599 }
600 pp_enable_irq (pp);
601 return ret;
602
603 case PPWCTLONIRQ:
604 if (copy_from_user (&reg, argp, sizeof (reg)))
605 return -EFAULT;
606
607 /* Remember what to set the control lines to, for next
608 * time we get an interrupt. */
609 pp->irqctl = reg;
610 pp->irqresponse = 1;
611 return 0;
612
613 case PPCLRIRQ:
614 ret = atomic_read (&pp->irqc);
615 if (copy_to_user (argp, &ret, sizeof (ret)))
616 return -EFAULT;
617 atomic_sub (ret, &pp->irqc);
618 return 0;
619
3b9ab374
BJZ		 620 case PPSETTIME32:
621 if (copy_from_user(time32, argp, sizeof(time32)))
1da177e4 622 return -EFAULT;
3b9ab374
BJZ		 623
624 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
625
626 case PPSETTIME64:
627 if (copy_from_user(time64, argp, sizeof(time64)))
628 return -EFAULT;
629
630 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
631
632 case PPGETTIME32:
633 jiffies_to_timespec64(pp->pdev->timeout, &ts);
634 time32[0] = ts.tv_sec;
635 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
636 if ((time32[0] < 0) || (time32[1] < 0))
1da177e4 637 return -EINVAL;
3b9ab374
BJZ		 638
639 if (copy_to_user(argp, time32, sizeof(time32)))
640 return -EFAULT;
641
1da177e4
LT		 642 return 0;
643
3b9ab374
BJZ		 644 case PPGETTIME64:
645 jiffies_to_timespec64(pp->pdev->timeout, &ts);
646 time64[0] = ts.tv_sec;
647 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
648 if ((time64[0] < 0) || (time64[1] < 0))
649 return -EINVAL;
650
651 if (copy_to_user(argp, time64, sizeof(time64)))
1da177e4 652 return -EFAULT;
3b9ab374 653
1da177e4
LT		 654 return 0;
655
656 default:
81fc401e 657 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
1da177e4
LT		 658 return -EINVAL;
659 }
660
661 /* Keep the compiler happy */
662 return 0;
663}
664
6d535d3e
AC		 665static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
666{
667 long ret;
613655fa 668 mutex_lock(&pp_do_mutex);
6d535d3e 669 ret = pp_do_ioctl(file, cmd, arg);
613655fa 670 mutex_unlock(&pp_do_mutex);
6d535d3e
AC		 671 return ret;
672}
673
17a3596f
BJZ		 674#ifdef CONFIG_COMPAT
675static long pp_compat_ioctl(struct file *file, unsigned int cmd,
676 unsigned long arg)
677{
678 return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
679}
680#endif
681
1da177e4
LT		 682static int pp_open (struct inode * inode, struct file * file)
683{
684 unsigned int minor = iminor(inode);
685 struct pp_struct *pp;
686
687 if (minor >= PARPORT_MAX)
688 return -ENXIO;
689
690 pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
691 if (!pp)
692 return -ENOMEM;
693
694 pp->state.mode = IEEE1284_MODE_COMPAT;
695 pp->state.phase = init_phase (pp->state.mode);
696 pp->flags = 0;
697 pp->irqresponse = 0;
698 atomic_set (&pp->irqc, 0);
699 init_waitqueue_head (&pp->irq_wait);
700
701 /* Defer the actual device registration until the first claim.
702 * That way, we know whether or not the driver wants to have
703 * exclusive access to the port (PPEXCL).
704 */
705 pp->pdev = NULL;
706 file->private_data = pp;
707
708 return 0;
709}
710
711static int pp_release (struct inode * inode, struct file * file)
712{
713 unsigned int minor = iminor(inode);
714 struct pp_struct *pp = file->private_data;
715 int compat_negot;
716
717 compat_negot = 0;
718 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
719 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
720 struct ieee1284_info *info;
721
722 /* parport released, but not in compatibility mode */
723 parport_claim_or_block (pp->pdev);
724 pp->flags |= PP_CLAIMED;
725 info = &pp->pdev->port->ieee1284;
726 pp->saved_state.mode = info->mode;
727 pp->saved_state.phase = info->phase;
728 info->mode = pp->state.mode;
729 info->phase = pp->state.phase;
730 compat_negot = 1;
731 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
732 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
733 compat_negot = 2;
734 }
735 if (compat_negot) {
736 parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
81fc401e
MB		 737 pr_debug(CHRDEV "%x: negotiated back to compatibility "
738 "mode because user-space forgot\n", minor);
1da177e4
LT		 739 }
740
741 if (pp->flags & PP_CLAIMED) {
742 struct ieee1284_info *info;
743
744 info = &pp->pdev->port->ieee1284;
745 pp->state.mode = info->mode;
746 pp->state.phase = info->phase;
747 info->mode = pp->saved_state.mode;
748 info->phase = pp->saved_state.phase;
749 parport_release (pp->pdev);
750 if (compat_negot != 1) {
81fc401e 751 pr_debug(CHRDEV "%x: released pardevice "
1da177e4
LT		 752 "because user-space forgot\n", minor);
753 }
754 }
755
756 if (pp->pdev) {
757 const char *name = pp->pdev->name;
758 parport_unregister_device (pp->pdev);
759 kfree (name);
760 pp->pdev = NULL;
81fc401e 761 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
1da177e4
LT		 762 }
763
764 kfree (pp);
765
766 return 0;
767}
768
769/* No kernel lock held - fine */
770static unsigned int pp_poll (struct file * file, poll_table * wait)
771{
772 struct pp_struct *pp = file->private_data;
773 unsigned int mask = 0;
774
775 poll_wait (file, &pp->irq_wait, wait);
776 if (atomic_read (&pp->irqc))
777 mask |= POLLIN | POLLRDNORM;
778
779 return mask;
780}
781
ca8eca68 782static struct class *ppdev_class;
1da177e4 783
62322d25 784static const struct file_operations pp_fops = {
1da177e4
LT		 785 .owner = THIS_MODULE,
786 .llseek = no_llseek,
787 .read = pp_read,
788 .write = pp_write,
789 .poll = pp_poll,
6d535d3e 790 .unlocked_ioctl = pp_ioctl,
17a3596f
BJZ		 791#ifdef CONFIG_COMPAT
792 .compat_ioctl = pp_compat_ioctl,
793#endif
1da177e4
LT		 794 .open = pp_open,
795 .release = pp_release,
796};
797
798static void pp_attach(struct parport *port)
799{
03457cd4
GKH		 800 device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
801 NULL, "parport%d", port->number);
1da177e4
LT		 802}
803
804static void pp_detach(struct parport *port)
805{
04880eda 806 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
1da177e4
LT		 807}
808
809static struct parport_driver pp_driver = {
810 .name = CHRDEV,
811 .attach = pp_attach,
812 .detach = pp_detach,
813};
814
815static int __init ppdev_init (void)
816{
8ab5e4c1 817 int err = 0;
1da177e4
LT		 818
819 if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
820 printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
821 PP_MAJOR);
822 return -EIO;
823 }
ca8eca68 824 ppdev_class = class_create(THIS_MODULE, CHRDEV);
1da177e4
LT		 825 if (IS_ERR(ppdev_class)) {
826 err = PTR_ERR(ppdev_class);
827 goto out_chrdev;
828 }
9a32bb39
AK		 829 err = parport_register_driver(&pp_driver);
830 if (err < 0) {
1da177e4
LT		 831 printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
832 goto out_class;
833 }
834
835 printk (KERN_INFO PP_VERSION "\n");
836 goto out;
837
838out_class:
ca8eca68 839 class_destroy(ppdev_class);
1da177e4
LT		 840out_chrdev:
841 unregister_chrdev(PP_MAJOR, CHRDEV);
842out:
843 return err;
844}
845
846static void __exit ppdev_cleanup (void)
847{
1da177e4 848 /* Clean up all parport stuff */
1da177e4 849 parport_unregister_driver(&pp_driver);
ca8eca68 850 class_destroy(ppdev_class);
1da177e4
LT		 851 unregister_chrdev (PP_MAJOR, CHRDEV);
852}
853
854module_init(ppdev_init);
855module_exit(ppdev_cleanup);
856
857MODULE_LICENSE("GPL");
858MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);
Linux 6.x block layer and io_uring tree(s)