2 * linux/drivers/char/ppdev.c
4 * This is the code behind /dev/parport* -- it allows a user-space
5 * application to use the parport subsystem.
7 * Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
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.
14 * A /dev/parportx device node represents an arbitrary device
15 * on port 'x'. The following operations are possible:
17 * open do nothing, set up default IEEE 1284 protocol to be COMPAT
18 * close release port and unregister device (if necessary)
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
29 * WCONTROL write_control
30 * RCONTROL read_control
31 * FCONTROL frob_control
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)
48 * Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
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
55 * Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
56 * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
59 #include <linux/module.h>
60 #include <linux/init.h>
61 #include <linux/sched.h>
62 #include <linux/device.h>
63 #include <linux/ioctl.h>
64 #include <linux/parport.h>
65 #include <linux/ctype.h>
66 #include <linux/poll.h>
67 #include <linux/slab.h>
68 #include <linux/major.h>
69 #include <linux/ppdev.h>
70 #include <linux/mutex.h>
71 #include <linux/uaccess.h>
73 #define PP_VERSION "ppdev: user-space parallel port driver"
74 #define CHRDEV "ppdev"
77 struct pardevice
* pdev
;
78 wait_queue_head_t irq_wait
;
83 struct ieee1284_info state
;
84 struct ieee1284_info saved_state
;
85 long default_inactivity
;
88 /* pp_struct.flags bitfields */
89 #define PP_CLAIMED (1<<0)
90 #define PP_EXCL (1<<1)
93 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
94 #define PP_BUFFER_SIZE 1024
95 #define PARDEVICE_MAX 8
97 /* ROUND_UP macro from fs/select.c */
98 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
100 static DEFINE_MUTEX(pp_do_mutex
);
101 static inline void pp_enable_irq (struct pp_struct
*pp
)
103 struct parport
*port
= pp
->pdev
->port
;
104 port
->ops
->enable_irq (port
);
107 static ssize_t
pp_read (struct file
* file
, char __user
* buf
, size_t count
,
110 unsigned int minor
= iminor(file_inode(file
));
111 struct pp_struct
*pp
= file
->private_data
;
113 ssize_t bytes_read
= 0;
114 struct parport
*pport
;
117 if (!(pp
->flags
& PP_CLAIMED
)) {
118 /* Don't have the port claimed */
119 pr_debug(CHRDEV
"%x: claim the port first\n", minor
);
127 kbuffer
= kmalloc(min_t(size_t, count
, PP_BUFFER_SIZE
), GFP_KERNEL
);
131 pport
= pp
->pdev
->port
;
132 mode
= pport
->ieee1284
.mode
& ~(IEEE1284_DEVICEID
| IEEE1284_ADDR
);
134 parport_set_timeout (pp
->pdev
,
135 (file
->f_flags
& O_NONBLOCK
) ?
136 PARPORT_INACTIVITY_O_NONBLOCK
:
137 pp
->default_inactivity
);
139 while (bytes_read
== 0) {
140 ssize_t need
= min_t(unsigned long, count
, PP_BUFFER_SIZE
);
142 if (mode
== IEEE1284_MODE_EPP
) {
143 /* various specials for EPP mode */
145 size_t (*fn
)(struct parport
*, void *, size_t, int);
147 if (pp
->flags
& PP_W91284PIC
) {
148 flags
|= PARPORT_W91284PIC
;
150 if (pp
->flags
& PP_FASTREAD
) {
151 flags
|= PARPORT_EPP_FAST
;
153 if (pport
->ieee1284
.mode
& IEEE1284_ADDR
) {
154 fn
= pport
->ops
->epp_read_addr
;
156 fn
= pport
->ops
->epp_read_data
;
158 bytes_read
= (*fn
)(pport
, kbuffer
, need
, flags
);
160 bytes_read
= parport_read (pport
, kbuffer
, need
);
166 if (file
->f_flags
& O_NONBLOCK
) {
167 bytes_read
= -EAGAIN
;
171 if (signal_pending (current
)) {
172 bytes_read
= -ERESTARTSYS
;
179 parport_set_timeout (pp
->pdev
, pp
->default_inactivity
);
181 if (bytes_read
> 0 && copy_to_user (buf
, kbuffer
, bytes_read
))
182 bytes_read
= -EFAULT
;
189 static ssize_t
pp_write (struct file
* file
, const char __user
* buf
,
190 size_t count
, loff_t
* ppos
)
192 unsigned int minor
= iminor(file_inode(file
));
193 struct pp_struct
*pp
= file
->private_data
;
195 ssize_t bytes_written
= 0;
198 struct parport
*pport
;
200 if (!(pp
->flags
& PP_CLAIMED
)) {
201 /* Don't have the port claimed */
202 pr_debug(CHRDEV
"%x: claim the port first\n", minor
);
206 kbuffer
= kmalloc(min_t(size_t, count
, PP_BUFFER_SIZE
), GFP_KERNEL
);
210 pport
= pp
->pdev
->port
;
211 mode
= pport
->ieee1284
.mode
& ~(IEEE1284_DEVICEID
| IEEE1284_ADDR
);
213 parport_set_timeout (pp
->pdev
,
214 (file
->f_flags
& O_NONBLOCK
) ?
215 PARPORT_INACTIVITY_O_NONBLOCK
:
216 pp
->default_inactivity
);
218 while (bytes_written
< count
) {
219 ssize_t n
= min_t(unsigned long, count
- bytes_written
, PP_BUFFER_SIZE
);
221 if (copy_from_user (kbuffer
, buf
+ bytes_written
, n
)) {
222 bytes_written
= -EFAULT
;
226 if ((pp
->flags
& PP_FASTWRITE
) && (mode
== IEEE1284_MODE_EPP
)) {
227 /* do a fast EPP write */
228 if (pport
->ieee1284
.mode
& IEEE1284_ADDR
) {
229 wrote
= pport
->ops
->epp_write_addr (pport
,
230 kbuffer
, n
, PARPORT_EPP_FAST
);
232 wrote
= pport
->ops
->epp_write_data (pport
,
233 kbuffer
, n
, PARPORT_EPP_FAST
);
236 wrote
= parport_write (pp
->pdev
->port
, kbuffer
, n
);
240 if (!bytes_written
) {
241 bytes_written
= wrote
;
246 bytes_written
+= wrote
;
248 if (file
->f_flags
& O_NONBLOCK
) {
250 bytes_written
= -EAGAIN
;
254 if (signal_pending (current
))
260 parport_set_timeout (pp
->pdev
, pp
->default_inactivity
);
264 return bytes_written
;
267 static void pp_irq (void *private)
269 struct pp_struct
*pp
= private;
271 if (pp
->irqresponse
) {
272 parport_write_control (pp
->pdev
->port
, pp
->irqctl
);
276 atomic_inc (&pp
->irqc
);
277 wake_up_interruptible (&pp
->irq_wait
);
280 static int register_device (int minor
, struct pp_struct
*pp
)
282 struct parport
*port
;
283 struct pardevice
* pdev
= NULL
;
287 name
= kasprintf(GFP_KERNEL
, CHRDEV
"%x", minor
);
291 port
= parport_find_number (minor
);
293 printk (KERN_WARNING
"%s: no associated port!\n", name
);
298 fl
= (pp
->flags
& PP_EXCL
) ? PARPORT_FLAG_EXCL
: 0;
299 pdev
= parport_register_device (port
, name
, NULL
,
300 NULL
, pp_irq
, fl
, pp
);
301 parport_put_port (port
);
304 printk (KERN_WARNING
"%s: failed to register device!\n", name
);
310 pr_debug("%s: registered pardevice\n", name
);
314 static enum ieee1284_phase
init_phase (int mode
)
316 switch (mode
& ~(IEEE1284_DEVICEID
318 case IEEE1284_MODE_NIBBLE
:
319 case IEEE1284_MODE_BYTE
:
320 return IEEE1284_PH_REV_IDLE
;
322 return IEEE1284_PH_FWD_IDLE
;
325 static int pp_do_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
327 unsigned int minor
= iminor(file_inode(file
));
328 struct pp_struct
*pp
= file
->private_data
;
329 struct parport
* port
;
330 void __user
*argp
= (void __user
*)arg
;
332 /* First handle the cases that don't take arguments. */
336 struct ieee1284_info
*info
;
339 if (pp
->flags
& PP_CLAIMED
) {
340 pr_debug(CHRDEV
"%x: you've already got it!\n", minor
);
344 /* Deferred device registration. */
346 int err
= register_device (minor
, pp
);
352 ret
= parport_claim_or_block (pp
->pdev
);
356 pp
->flags
|= PP_CLAIMED
;
358 /* For interrupt-reporting to work, we need to be
359 * informed of each interrupt. */
362 /* We may need to fix up the state machine. */
363 info
= &pp
->pdev
->port
->ieee1284
;
364 pp
->saved_state
.mode
= info
->mode
;
365 pp
->saved_state
.phase
= info
->phase
;
366 info
->mode
= pp
->state
.mode
;
367 info
->phase
= pp
->state
.phase
;
368 pp
->default_inactivity
= parport_set_timeout (pp
->pdev
, 0);
369 parport_set_timeout (pp
->pdev
, pp
->default_inactivity
);
375 pr_debug(CHRDEV
"%x: too late for PPEXCL; "
376 "already registered\n", minor
);
377 if (pp
->flags
& PP_EXCL
)
378 /* But it's not really an error. */
380 /* There's no chance of making the driver happy. */
384 /* Just remember to register the device exclusively
385 * when we finally do the registration. */
386 pp
->flags
|= PP_EXCL
;
391 if (copy_from_user (&mode
, argp
, sizeof (mode
)))
393 /* FIXME: validate mode */
394 pp
->state
.mode
= mode
;
395 pp
->state
.phase
= init_phase (mode
);
397 if (pp
->flags
& PP_CLAIMED
) {
398 pp
->pdev
->port
->ieee1284
.mode
= mode
;
399 pp
->pdev
->port
->ieee1284
.phase
= pp
->state
.phase
;
408 if (pp
->flags
& PP_CLAIMED
) {
409 mode
= pp
->pdev
->port
->ieee1284
.mode
;
411 mode
= pp
->state
.mode
;
413 if (copy_to_user (argp
, &mode
, sizeof (mode
))) {
421 if (copy_from_user (&phase
, argp
, sizeof (phase
))) {
424 /* FIXME: validate phase */
425 pp
->state
.phase
= phase
;
427 if (pp
->flags
& PP_CLAIMED
) {
428 pp
->pdev
->port
->ieee1284
.phase
= phase
;
437 if (pp
->flags
& PP_CLAIMED
) {
438 phase
= pp
->pdev
->port
->ieee1284
.phase
;
440 phase
= pp
->state
.phase
;
442 if (copy_to_user (argp
, &phase
, sizeof (phase
))) {
451 port
= parport_find_number (minor
);
456 parport_put_port(port
);
457 if (copy_to_user (argp
, &modes
, sizeof (modes
))) {
466 if (copy_from_user (&uflags
, argp
, sizeof (uflags
))) {
469 pp
->flags
&= ~PP_FLAGMASK
;
470 pp
->flags
|= (uflags
& PP_FLAGMASK
);
477 uflags
= pp
->flags
& PP_FLAGMASK
;
478 if (copy_to_user (argp
, &uflags
, sizeof (uflags
))) {
485 /* Everything else requires the port to be claimed, so check
487 if ((pp
->flags
& PP_CLAIMED
) == 0) {
488 pr_debug(CHRDEV
"%x: claim the port first\n", minor
);
492 port
= pp
->pdev
->port
;
494 struct ieee1284_info
*info
;
499 struct timeval par_timeout
;
503 reg
= parport_read_status (port
);
504 if (copy_to_user (argp
, ®
, sizeof (reg
)))
508 reg
= parport_read_data (port
);
509 if (copy_to_user (argp
, ®
, sizeof (reg
)))
513 reg
= parport_read_control (port
);
514 if (copy_to_user (argp
, ®
, sizeof (reg
)))
518 parport_yield_blocking (pp
->pdev
);
522 /* Save the state machine's state. */
523 info
= &pp
->pdev
->port
->ieee1284
;
524 pp
->state
.mode
= info
->mode
;
525 pp
->state
.phase
= info
->phase
;
526 info
->mode
= pp
->saved_state
.mode
;
527 info
->phase
= pp
->saved_state
.phase
;
528 parport_release (pp
->pdev
);
529 pp
->flags
&= ~PP_CLAIMED
;
533 if (copy_from_user (®
, argp
, sizeof (reg
)))
535 parport_write_control (port
, reg
);
539 if (copy_from_user (®
, argp
, sizeof (reg
)))
541 parport_write_data (port
, reg
);
545 if (copy_from_user (&mask
, argp
,
548 if (copy_from_user (®
, 1 + (unsigned char __user
*) arg
,
551 parport_frob_control (port
, mask
, reg
);
555 if (copy_from_user (&mode
, argp
, sizeof (mode
)))
558 port
->ops
->data_reverse (port
);
560 port
->ops
->data_forward (port
);
564 if (copy_from_user (&mode
, argp
, sizeof (mode
)))
566 switch ((ret
= parport_negotiate (port
, mode
))) {
568 case -1: /* handshake failed, peripheral not IEEE 1284 */
571 case 1: /* handshake succeeded, peripheral rejected mode */
579 if (copy_from_user (®
, argp
, sizeof (reg
)))
582 /* Remember what to set the control lines to, for next
583 * time we get an interrupt. */
589 ret
= atomic_read (&pp
->irqc
);
590 if (copy_to_user (argp
, &ret
, sizeof (ret
)))
592 atomic_sub (ret
, &pp
->irqc
);
596 if (copy_from_user (&par_timeout
, argp
, sizeof(struct timeval
))) {
599 /* Convert to jiffies, place in pp->pdev->timeout */
600 if ((par_timeout
.tv_sec
< 0) || (par_timeout
.tv_usec
< 0)) {
603 to_jiffies
= ROUND_UP(par_timeout
.tv_usec
, 1000000/HZ
);
604 to_jiffies
+= par_timeout
.tv_sec
* (long)HZ
;
605 if (to_jiffies
<= 0) {
608 pp
->pdev
->timeout
= to_jiffies
;
612 to_jiffies
= pp
->pdev
->timeout
;
613 memset(&par_timeout
, 0, sizeof(par_timeout
));
614 par_timeout
.tv_sec
= to_jiffies
/ HZ
;
615 par_timeout
.tv_usec
= (to_jiffies
% (long)HZ
) * (1000000/HZ
);
616 if (copy_to_user (argp
, &par_timeout
, sizeof(struct timeval
)))
621 pr_debug(CHRDEV
"%x: What? (cmd=0x%x)\n", minor
, cmd
);
625 /* Keep the compiler happy */
629 static long pp_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
632 mutex_lock(&pp_do_mutex
);
633 ret
= pp_do_ioctl(file
, cmd
, arg
);
634 mutex_unlock(&pp_do_mutex
);
638 static int pp_open (struct inode
* inode
, struct file
* file
)
640 unsigned int minor
= iminor(inode
);
641 struct pp_struct
*pp
;
643 if (minor
>= PARPORT_MAX
)
646 pp
= kmalloc (sizeof (struct pp_struct
), GFP_KERNEL
);
650 pp
->state
.mode
= IEEE1284_MODE_COMPAT
;
651 pp
->state
.phase
= init_phase (pp
->state
.mode
);
654 atomic_set (&pp
->irqc
, 0);
655 init_waitqueue_head (&pp
->irq_wait
);
657 /* Defer the actual device registration until the first claim.
658 * That way, we know whether or not the driver wants to have
659 * exclusive access to the port (PPEXCL).
662 file
->private_data
= pp
;
667 static int pp_release (struct inode
* inode
, struct file
* file
)
669 unsigned int minor
= iminor(inode
);
670 struct pp_struct
*pp
= file
->private_data
;
674 if (!(pp
->flags
& PP_CLAIMED
) && pp
->pdev
&&
675 (pp
->state
.mode
!= IEEE1284_MODE_COMPAT
)) {
676 struct ieee1284_info
*info
;
678 /* parport released, but not in compatibility mode */
679 parport_claim_or_block (pp
->pdev
);
680 pp
->flags
|= PP_CLAIMED
;
681 info
= &pp
->pdev
->port
->ieee1284
;
682 pp
->saved_state
.mode
= info
->mode
;
683 pp
->saved_state
.phase
= info
->phase
;
684 info
->mode
= pp
->state
.mode
;
685 info
->phase
= pp
->state
.phase
;
687 } else if ((pp
->flags
& PP_CLAIMED
) && pp
->pdev
&&
688 (pp
->pdev
->port
->ieee1284
.mode
!= IEEE1284_MODE_COMPAT
)) {
692 parport_negotiate (pp
->pdev
->port
, IEEE1284_MODE_COMPAT
);
693 pr_debug(CHRDEV
"%x: negotiated back to compatibility "
694 "mode because user-space forgot\n", minor
);
697 if (pp
->flags
& PP_CLAIMED
) {
698 struct ieee1284_info
*info
;
700 info
= &pp
->pdev
->port
->ieee1284
;
701 pp
->state
.mode
= info
->mode
;
702 pp
->state
.phase
= info
->phase
;
703 info
->mode
= pp
->saved_state
.mode
;
704 info
->phase
= pp
->saved_state
.phase
;
705 parport_release (pp
->pdev
);
706 if (compat_negot
!= 1) {
707 pr_debug(CHRDEV
"%x: released pardevice "
708 "because user-space forgot\n", minor
);
713 const char *name
= pp
->pdev
->name
;
714 parport_unregister_device (pp
->pdev
);
717 pr_debug(CHRDEV
"%x: unregistered pardevice\n", minor
);
725 /* No kernel lock held - fine */
726 static unsigned int pp_poll (struct file
* file
, poll_table
* wait
)
728 struct pp_struct
*pp
= file
->private_data
;
729 unsigned int mask
= 0;
731 poll_wait (file
, &pp
->irq_wait
, wait
);
732 if (atomic_read (&pp
->irqc
))
733 mask
|= POLLIN
| POLLRDNORM
;
738 static struct class *ppdev_class
;
740 static const struct file_operations pp_fops
= {
741 .owner
= THIS_MODULE
,
746 .unlocked_ioctl
= pp_ioctl
,
748 .release
= pp_release
,
751 static void pp_attach(struct parport
*port
)
753 device_create(ppdev_class
, port
->dev
, MKDEV(PP_MAJOR
, port
->number
),
754 NULL
, "parport%d", port
->number
);
757 static void pp_detach(struct parport
*port
)
759 device_destroy(ppdev_class
, MKDEV(PP_MAJOR
, port
->number
));
762 static struct parport_driver pp_driver
= {
768 static int __init
ppdev_init (void)
772 if (register_chrdev (PP_MAJOR
, CHRDEV
, &pp_fops
)) {
773 printk (KERN_WARNING CHRDEV
": unable to get major %d\n",
777 ppdev_class
= class_create(THIS_MODULE
, CHRDEV
);
778 if (IS_ERR(ppdev_class
)) {
779 err
= PTR_ERR(ppdev_class
);
782 err
= parport_register_driver(&pp_driver
);
784 printk (KERN_WARNING CHRDEV
": unable to register with parport\n");
788 printk (KERN_INFO PP_VERSION
"\n");
792 class_destroy(ppdev_class
);
794 unregister_chrdev(PP_MAJOR
, CHRDEV
);
799 static void __exit
ppdev_cleanup (void)
801 /* Clean up all parport stuff */
802 parport_unregister_driver(&pp_driver
);
803 class_destroy(ppdev_class
);
804 unregister_chrdev (PP_MAJOR
, CHRDEV
);
807 module_init(ppdev_init
);
808 module_exit(ppdev_cleanup
);
810 MODULE_LICENSE("GPL");
811 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR
);