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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [char/] [ppdev.c] - Blame information for rev 65

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1 62 marcus.erl 
/*
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/major.h>
68 
#include <linux/ppdev.h>
69 
#include <asm/uaccess.h>
70 
 
71 
#define PP_VERSION "ppdev: user-space parallel port driver"
72 
#define CHRDEV "ppdev"
73 
 
74 
struct pp_struct {
75 
        struct pardevice * pdev;
76 
        wait_queue_head_t irq_wait;
77 
        atomic_t irqc;
78 
        unsigned int flags;
79 
        int irqresponse;
80 
        unsigned char irqctl;
81 
        struct ieee1284_info state;
82 
        struct ieee1284_info saved_state;
83 
        long default_inactivity;
84 
};
85 
 
86 
/* pp_struct.flags bitfields */
87 
#define PP_CLAIMED    (1<<0)
88 
#define PP_EXCL       (1<<1)
89 
 
90 
/* Other constants */
91 
#define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
92 
#define PP_BUFFER_SIZE 1024
93 
#define PARDEVICE_MAX 8
94 
 
95 
/* ROUND_UP macro from fs/select.c */
96 
#define ROUND_UP(x,y) (((x)+(y)-1)/(y))
97 
 
98 
static inline void pp_enable_irq (struct pp_struct *pp)
99 
{
100 
        struct parport *port = pp->pdev->port;
101 
        port->ops->enable_irq (port);
102 
}
103 
 
104 
static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
105 
                        loff_t * ppos)
106 
{
107 
        unsigned int minor = iminor(file->f_path.dentry->d_inode);
108 
        struct pp_struct *pp = file->private_data;
109 
        char * kbuffer;
110 
        ssize_t bytes_read = 0;
111 
        struct parport *pport;
112 
        int mode;
113 
 
114 
        if (!(pp->flags & PP_CLAIMED)) {
115 
                /* Don't have the port claimed */
116 
                printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
117 
                        minor);
118 
                return -EINVAL;
119 
        }
120 
 
121 
        /* Trivial case. */
122 
        if (count == 0)
123 
                return 0;
124 
 
125 
        kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
126 
        if (!kbuffer) {
127 
                return -ENOMEM;
128 
        }
129 
        pport = pp->pdev->port;
130 
        mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
131 
 
132 
        parport_set_timeout (pp->pdev,
133 
                             (file->f_flags & O_NONBLOCK) ?
134 
                             PARPORT_INACTIVITY_O_NONBLOCK :
135 
                             pp->default_inactivity);
136 
 
137 
        while (bytes_read == 0) {
138 
                ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
139 
 
140 
                if (mode == IEEE1284_MODE_EPP) {
141 
                        /* various specials for EPP mode */
142 
                        int flags = 0;
143 
                        size_t (*fn)(struct parport *, void *, size_t, int);
144 
 
145 
                        if (pp->flags & PP_W91284PIC) {
146 
                                flags |= PARPORT_W91284PIC;
147 
                        }
148 
                        if (pp->flags & PP_FASTREAD) {
149 
                                flags |= PARPORT_EPP_FAST;
150 
                        }
151 
                        if (pport->ieee1284.mode & IEEE1284_ADDR) {
152 
                                fn = pport->ops->epp_read_addr;
153 
                        } else {
154 
                                fn = pport->ops->epp_read_data;
155 
                        }
156 
                        bytes_read = (*fn)(pport, kbuffer, need, flags);
157 
                } else {
158 
                        bytes_read = parport_read (pport, kbuffer, need);
159 
                }
160 
 
161 
                if (bytes_read != 0)
162 
                        break;
163 
 
164 
                if (file->f_flags & O_NONBLOCK) {
165 
                        bytes_read = -EAGAIN;
166 
                        break;
167 
                }
168 
 
169 
                if (signal_pending (current)) {
170 
                        bytes_read = -ERESTARTSYS;
171 
                        break;
172 
                }
173 
 
174 
                cond_resched();
175 
        }
176 
 
177 
        parport_set_timeout (pp->pdev, pp->default_inactivity);
178 
 
179 
        if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
180 
                bytes_read = -EFAULT;
181 
 
182 
        kfree (kbuffer);
183 
        pp_enable_irq (pp);
184 
        return bytes_read;
185 
}
186 
 
187 
static ssize_t pp_write (struct file * file, const char __user * buf,
188 
                         size_t count, loff_t * ppos)
189 
{
190 
        unsigned int minor = iminor(file->f_path.dentry->d_inode);
191 
        struct pp_struct *pp = file->private_data;
192 
        char * kbuffer;
193 
        ssize_t bytes_written = 0;
194 
        ssize_t wrote;
195 
        int mode;
196 
        struct parport *pport;
197 
 
198 
        if (!(pp->flags & PP_CLAIMED)) {
199 
                /* Don't have the port claimed */
200 
                printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
201 
                        minor);
202 
                return -EINVAL;
203 
        }
204 
 
205 
        kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
206 
        if (!kbuffer) {
207 
                return -ENOMEM;
208 
        }
209 
        pport = pp->pdev->port;
210 
        mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
211 
 
212 
        parport_set_timeout (pp->pdev,
213 
                             (file->f_flags & O_NONBLOCK) ?
214 
                             PARPORT_INACTIVITY_O_NONBLOCK :
215 
                             pp->default_inactivity);
216 
 
217 
        while (bytes_written < count) {
218 
                ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
219 
 
220 
                if (copy_from_user (kbuffer, buf + bytes_written, n)) {
221 
                        bytes_written = -EFAULT;
222 
                        break;
223 
                }
224 
 
225 
                if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
226 
                        /* do a fast EPP write */
227 
                        if (pport->ieee1284.mode & IEEE1284_ADDR) {
228 
                                wrote = pport->ops->epp_write_addr (pport,
229 
                                        kbuffer, n, PARPORT_EPP_FAST);
230 
                        } else {
231 
                                wrote = pport->ops->epp_write_data (pport,
232 
                                        kbuffer, n, PARPORT_EPP_FAST);
233 
                        }
234 
                } else {
235 
                        wrote = parport_write (pp->pdev->port, kbuffer, n);
236 
                }
237 
 
238 
                if (wrote <= 0) {
239 
                        if (!bytes_written) {
240 
                                bytes_written = wrote;
241 
                        }
242 
                        break;
243 
                }
244 
 
245 
                bytes_written += wrote;
246 
 
247 
                if (file->f_flags & O_NONBLOCK) {
248 
                        if (!bytes_written)
249 
                                bytes_written = -EAGAIN;
250 
                        break;
251 
                }
252 
 
253 
                if (signal_pending (current)) {
254 
                        if (!bytes_written) {
255 
                                bytes_written = -EINTR;
256 
                        }
257 
                        break;
258 
                }
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 
 
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 
 
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 
        int fl;
289 
 
290 
        name = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
291 
        if (name == NULL)
292 
                return -ENOMEM;
293 
 
294 
        sprintf (name, CHRDEV "%x", minor);
295 
 
296 
        port = parport_find_number (minor);
297 
        if (!port) {
298 
                printk (KERN_WARNING "%s: no associated port!\n", name);
299 
                kfree (name);
300 
                return -ENXIO;
301 
        }
302 
 
303 
        fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
304 
        pdev = parport_register_device (port, name, NULL,
305 
                                        NULL, pp_irq, fl, pp);
306 
        parport_put_port (port);
307 
 
308 
        if (!pdev) {
309 
                printk (KERN_WARNING "%s: failed to register device!\n", name);
310 
                kfree (name);
311 
                return -ENXIO;
312 
        }
313 
 
314 
        pp->pdev = pdev;
315 
        printk (KERN_DEBUG "%s: registered pardevice\n", name);
316 
        return 0;
317 
}
318 
 
319 
static enum ieee1284_phase init_phase (int mode)
320 
{
321 
        switch (mode & ~(IEEE1284_DEVICEID
322 
                         | IEEE1284_ADDR)) {
323 
        case IEEE1284_MODE_NIBBLE:
324 
        case IEEE1284_MODE_BYTE:
325 
                return IEEE1284_PH_REV_IDLE;
326 
        }
327 
        return IEEE1284_PH_FWD_IDLE;
328 
}
329 
 
330 
static int pp_ioctl(struct inode *inode, struct file *file,
331 
                    unsigned int cmd, unsigned long arg)
332 
{
333 
        unsigned int minor = iminor(inode);
334 
        struct pp_struct *pp = file->private_data;
335 
        struct parport * port;
336 
        void __user *argp = (void __user *)arg;
337 
 
338 
        /* First handle the cases that don't take arguments. */
339 
        switch (cmd) {
340 
        case PPCLAIM:
341 
            {
342 
                struct ieee1284_info *info;
343 
                int ret;
344 
 
345 
                if (pp->flags & PP_CLAIMED) {
346 
                        printk (KERN_DEBUG CHRDEV
347 
                                "%x: you've already got it!\n", minor);
348 
                        return -EINVAL;
349 
                }
350 
 
351 
                /* Deferred device registration. */
352 
                if (!pp->pdev) {
353 
                        int err = register_device (minor, pp);
354 
                        if (err) {
355 
                                return err;
356 
                        }
357 
                }
358 
 
359 
                ret = parport_claim_or_block (pp->pdev);
360 
                if (ret < 0)
361 
                        return ret;
362 
 
363 
                pp->flags |= PP_CLAIMED;
364 
 
365 
                /* For interrupt-reporting to work, we need to be
366 
                 * informed of each interrupt. */
367 
                pp_enable_irq (pp);
368 
 
369 
                /* We may need to fix up the state machine. */
370 
                info = &pp->pdev->port->ieee1284;
371 
                pp->saved_state.mode = info->mode;
372 
                pp->saved_state.phase = info->phase;
373 
                info->mode = pp->state.mode;
374 
                info->phase = pp->state.phase;
375 
                pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
376 
                parport_set_timeout (pp->pdev, pp->default_inactivity);
377 
 
378 
                return 0;
379 
            }
380 
        case PPEXCL:
381 
                if (pp->pdev) {
382 
                        printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
383 
                                "already registered\n", minor);
384 
                        if (pp->flags & PP_EXCL)
385 
                                /* But it's not really an error. */
386 
                                return 0;
387 
                        /* There's no chance of making the driver happy. */
388 
                        return -EINVAL;
389 
                }
390 
 
391 
                /* Just remember to register the device exclusively
392 
                 * when we finally do the registration. */
393 
                pp->flags |= PP_EXCL;
394 
                return 0;
395 
        case PPSETMODE:
396 
            {
397 
                int mode;
398 
                if (copy_from_user (&mode, argp, sizeof (mode)))
399 
                        return -EFAULT;
400 
                /* FIXME: validate mode */
401 
                pp->state.mode = mode;
402 
                pp->state.phase = init_phase (mode);
403 
 
404 
                if (pp->flags & PP_CLAIMED) {
405 
                        pp->pdev->port->ieee1284.mode = mode;
406 
                        pp->pdev->port->ieee1284.phase = pp->state.phase;
407 
                }
408 
 
409 
                return 0;
410 
            }
411 
        case PPGETMODE:
412 
            {
413 
                int mode;
414 
 
415 
                if (pp->flags & PP_CLAIMED) {
416 
                        mode = pp->pdev->port->ieee1284.mode;
417 
                } else {
418 
                        mode = pp->state.mode;
419 
                }
420 
                if (copy_to_user (argp, &mode, sizeof (mode))) {
421 
                        return -EFAULT;
422 
                }
423 
                return 0;
424 
            }
425 
        case PPSETPHASE:
426 
            {
427 
                int phase;
428 
                if (copy_from_user (&phase, argp, sizeof (phase))) {
429 
                        return -EFAULT;
430 
                }
431 
                /* FIXME: validate phase */
432 
                pp->state.phase = phase;
433 
 
434 
                if (pp->flags & PP_CLAIMED) {
435 
                        pp->pdev->port->ieee1284.phase = phase;
436 
                }
437 
 
438 
                return 0;
439 
            }
440 
        case PPGETPHASE:
441 
            {
442 
                int phase;
443 
 
444 
                if (pp->flags & PP_CLAIMED) {
445 
                        phase = pp->pdev->port->ieee1284.phase;
446 
                } else {
447 
                        phase = pp->state.phase;
448 
                }
449 
                if (copy_to_user (argp, &phase, sizeof (phase))) {
450 
                        return -EFAULT;
451 
                }
452 
                return 0;
453 
            }
454 
        case PPGETMODES:
455 
            {
456 
                unsigned int modes;
457 
 
458 
                port = parport_find_number (minor);
459 
                if (!port)
460 
                        return -ENODEV;
461 
 
462 
                modes = port->modes;
463 
                if (copy_to_user (argp, &modes, sizeof (modes))) {
464 
                        return -EFAULT;
465 
                }
466 
                return 0;
467 
            }
468 
        case PPSETFLAGS:
469 
            {
470 
                int uflags;
471 
 
472 
                if (copy_from_user (&uflags, argp, sizeof (uflags))) {
473 
                        return -EFAULT;
474 
                }
475 
                pp->flags &= ~PP_FLAGMASK;
476 
                pp->flags |= (uflags & PP_FLAGMASK);
477 
                return 0;
478 
            }
479 
        case PPGETFLAGS:
480 
            {
481 
                int uflags;
482 
 
483 
                uflags = pp->flags & PP_FLAGMASK;
484 
                if (copy_to_user (argp, &uflags, sizeof (uflags))) {
485 
                        return -EFAULT;
486 
                }
487 
                return 0;
488 
            }
489 
        }       /* end switch() */
490 
 
491 
        /* Everything else requires the port to be claimed, so check
492 
         * that now. */
493 
        if ((pp->flags & PP_CLAIMED) == 0) {
494 
                printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
495 
                        minor);
496 
                return -EINVAL;
497 
        }
498 
 
499 
        port = pp->pdev->port;
500 
        switch (cmd) {
501 
                struct ieee1284_info *info;
502 
                unsigned char reg;
503 
                unsigned char mask;
504 
                int mode;
505 
                int ret;
506 
                struct timeval par_timeout;
507 
                long to_jiffies;
508 
 
509 
        case PPRSTATUS:
510 
                reg = parport_read_status (port);
511 
                if (copy_to_user (argp, &reg, sizeof (reg)))
512 
                        return -EFAULT;
513 
                return 0;
514 
        case PPRDATA:
515 
                reg = parport_read_data (port);
516 
                if (copy_to_user (argp, &reg, sizeof (reg)))
517 
                        return -EFAULT;
518 
                return 0;
519 
        case PPRCONTROL:
520 
                reg = parport_read_control (port);
521 
                if (copy_to_user (argp, &reg, sizeof (reg)))
522 
                        return -EFAULT;
523 
                return 0;
524 
        case PPYIELD:
525 
                parport_yield_blocking (pp->pdev);
526 
                return 0;
527 
 
528 
        case PPRELEASE:
529 
                /* Save the state machine's state. */
530 
                info = &pp->pdev->port->ieee1284;
531 
                pp->state.mode = info->mode;
532 
                pp->state.phase = info->phase;
533 
                info->mode = pp->saved_state.mode;
534 
                info->phase = pp->saved_state.phase;
535 
                parport_release (pp->pdev);
536 
                pp->flags &= ~PP_CLAIMED;
537 
                return 0;
538 
 
539 
        case PPWCONTROL:
540 
                if (copy_from_user (&reg, argp, sizeof (reg)))
541 
                        return -EFAULT;
542 
                parport_write_control (port, reg);
543 
                return 0;
544 
 
545 
        case PPWDATA:
546 
                if (copy_from_user (&reg, argp, sizeof (reg)))
547 
                        return -EFAULT;
548 
                parport_write_data (port, reg);
549 
                return 0;
550 
 
551 
        case PPFCONTROL:
552 
                if (copy_from_user (&mask, argp,
553 
                                    sizeof (mask)))
554 
                        return -EFAULT;
555 
                if (copy_from_user (&reg, 1 + (unsigned char __user *) arg,
556 
                                    sizeof (reg)))
557 
                        return -EFAULT;
558 
                parport_frob_control (port, mask, reg);
559 
                return 0;
560 
 
561 
        case PPDATADIR:
562 
                if (copy_from_user (&mode, argp, sizeof (mode)))
563 
                        return -EFAULT;
564 
                if (mode)
565 
                        port->ops->data_reverse (port);
566 
                else
567 
                        port->ops->data_forward (port);
568 
                return 0;
569 
 
570 
        case PPNEGOT:
571 
                if (copy_from_user (&mode, argp, sizeof (mode)))
572 
                        return -EFAULT;
573 
                switch ((ret = parport_negotiate (port, mode))) {
574 
                case 0: break;
575 
                case -1: /* handshake failed, peripheral not IEEE 1284 */
576 
                        ret = -EIO;
577 
                        break;
578 
                case 1:  /* handshake succeeded, peripheral rejected mode */
579 
                        ret = -ENXIO;
580 
                        break;
581 
                }
582 
                pp_enable_irq (pp);
583 
                return ret;
584 
 
585 
        case PPWCTLONIRQ:
586 
                if (copy_from_user (&reg, argp, sizeof (reg)))
587 
                        return -EFAULT;
588 
 
589 
                /* Remember what to set the control lines to, for next
590 
                 * time we get an interrupt. */
591 
                pp->irqctl = reg;
592 
                pp->irqresponse = 1;
593 
                return 0;
594 
 
595 
        case PPCLRIRQ:
596 
                ret = atomic_read (&pp->irqc);
597 
                if (copy_to_user (argp, &ret, sizeof (ret)))
598 
                        return -EFAULT;
599 
                atomic_sub (ret, &pp->irqc);
600 
                return 0;
601 
 
602 
        case PPSETTIME:
603 
                if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
604 
                        return -EFAULT;
605 
                }
606 
                /* Convert to jiffies, place in pp->pdev->timeout */
607 
                if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
608 
                        return -EINVAL;
609 
                }
610 
                to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
611 
                to_jiffies += par_timeout.tv_sec * (long)HZ;
612 
                if (to_jiffies <= 0) {
613 
                        return -EINVAL;
614 
                }
615 
                pp->pdev->timeout = to_jiffies;
616 
                return 0;
617 
 
618 
        case PPGETTIME:
619 
                to_jiffies = pp->pdev->timeout;
620 
                par_timeout.tv_sec = to_jiffies / HZ;
621 
                par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
622 
                if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
623 
                        return -EFAULT;
624 
                return 0;
625 
 
626 
        default:
627 
                printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
628 
                        cmd);
629 
                return -EINVAL;
630 
        }
631 
 
632 
        /* Keep the compiler happy */
633 
        return 0;
634 
}
635 
 
636 
static int pp_open (struct inode * inode, struct file * file)
637 
{
638 
        unsigned int minor = iminor(inode);
639 
        struct pp_struct *pp;
640 
 
641 
        if (minor >= PARPORT_MAX)
642 
                return -ENXIO;
643 
 
644 
        pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
645 
        if (!pp)
646 
                return -ENOMEM;
647 
 
648 
        pp->state.mode = IEEE1284_MODE_COMPAT;
649 
        pp->state.phase = init_phase (pp->state.mode);
650 
        pp->flags = 0;
651 
        pp->irqresponse = 0;
652 
        atomic_set (&pp->irqc, 0);
653 
        init_waitqueue_head (&pp->irq_wait);
654 
 
655 
        /* Defer the actual device registration until the first claim.
656 
         * That way, we know whether or not the driver wants to have
657 
         * exclusive access to the port (PPEXCL).
658 
         */
659 
        pp->pdev = NULL;
660 
        file->private_data = pp;
661 
 
662 
        return 0;
663 
}
664 
 
665 
static int pp_release (struct inode * inode, struct file * file)
666 
{
667 
        unsigned int minor = iminor(inode);
668 
        struct pp_struct *pp = file->private_data;
669 
        int compat_negot;
670 
 
671 
        compat_negot = 0;
672 
        if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
673 
            (pp->state.mode != IEEE1284_MODE_COMPAT)) {
674 
                struct ieee1284_info *info;
675 
 
676 
                /* parport released, but not in compatibility mode */
677 
                parport_claim_or_block (pp->pdev);
678 
                pp->flags |= PP_CLAIMED;
679 
                info = &pp->pdev->port->ieee1284;
680 
                pp->saved_state.mode = info->mode;
681 
                pp->saved_state.phase = info->phase;
682 
                info->mode = pp->state.mode;
683 
                info->phase = pp->state.phase;
684 
                compat_negot = 1;
685 
        } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
686 
            (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
687 
                compat_negot = 2;
688 
        }
689 
        if (compat_negot) {
690 
                parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
691 
                printk (KERN_DEBUG CHRDEV
692 
                        "%x: negotiated back to compatibility mode because "
693 
                        "user-space forgot\n", minor);
694 
        }
695 
 
696 
        if (pp->flags & PP_CLAIMED) {
697 
                struct ieee1284_info *info;
698 
 
699 
                info = &pp->pdev->port->ieee1284;
700 
                pp->state.mode = info->mode;
701 
                pp->state.phase = info->phase;
702 
                info->mode = pp->saved_state.mode;
703 
                info->phase = pp->saved_state.phase;
704 
                parport_release (pp->pdev);
705 
                if (compat_negot != 1) {
706 
                        printk (KERN_DEBUG CHRDEV "%x: released pardevice "
707 
                                "because user-space forgot\n", minor);
708 
                }
709 
        }
710 
 
711 
        if (pp->pdev) {
712 
                const char *name = pp->pdev->name;
713 
                parport_unregister_device (pp->pdev);
714 
                kfree (name);
715 
                pp->pdev = NULL;
716 
                printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
717 
                        minor);
718 
        }
719 
 
720 
        kfree (pp);
721 
 
722 
        return 0;
723 
}
724 
 
725 
/* No kernel lock held - fine */
726 
static 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 
 
738 
static struct class *ppdev_class;
739 
 
740 
static 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 
        .ioctl          = pp_ioctl,
747 
        .open           = pp_open,
748 
        .release        = pp_release,
749 
};
750 
 
751 
static void pp_attach(struct parport *port)
752 
{
753 
        device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
754 
                        "parport%d", port->number);
755 
}
756 
 
757 
static void pp_detach(struct parport *port)
758 
{
759 
        device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
760 
}
761 
 
762 
static struct parport_driver pp_driver = {
763 
        .name           = CHRDEV,
764 
        .attach         = pp_attach,
765 
        .detach         = pp_detach,
766 
};
767 
 
768 
static 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 
        if (parport_register_driver(&pp_driver)) {
783 
                printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
784 
                goto out_class;
785 
        }
786 
 
787 
        printk (KERN_INFO PP_VERSION "\n");
788 
        goto out;
789 
 
790 
out_class:
791 
        class_destroy(ppdev_class);
792 
out_chrdev:
793 
        unregister_chrdev(PP_MAJOR, CHRDEV);
794 
out:
795 
        return err;
796 
}
797 
 
798 
static void __exit ppdev_cleanup (void)
799 
{
800 
        /* Clean up all parport stuff */
801 
        parport_unregister_driver(&pp_driver);
802 
        class_destroy(ppdev_class);
803 
        unregister_chrdev (PP_MAJOR, CHRDEV);
804 
}
805 
 
806 
module_init(ppdev_init);
807 
module_exit(ppdev_cleanup);
808 
 
809 
MODULE_LICENSE("GPL");
810 
MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);

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