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->f_path.dentry->d_inode);
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->f_path.dentry->d_inode);
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)) {
255
if (!bytes_written) {
256
bytes_written = -EINTR;
264
parport_set_timeout (pp->pdev, pp->default_inactivity);
268
return bytes_written;
271
static void pp_irq (void *private)
273
struct pp_struct *pp = private;
275
if (pp->irqresponse) {
276
parport_write_control (pp->pdev->port, pp->irqctl);
280
atomic_inc (&pp->irqc);
281
wake_up_interruptible (&pp->irq_wait);
284
static int register_device (int minor, struct pp_struct *pp)
286
struct parport *port;
287
struct pardevice * pdev = NULL;
291
name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
295
port = parport_find_number (minor);
297
printk (KERN_WARNING "%s: no associated port!\n", name);
302
fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
303
pdev = parport_register_device (port, name, NULL,
304
NULL, pp_irq, fl, pp);
305
parport_put_port (port);
308
printk (KERN_WARNING "%s: failed to register device!\n", name);
314
pr_debug("%s: registered pardevice\n", name);
318
static enum ieee1284_phase init_phase (int mode)
320
switch (mode & ~(IEEE1284_DEVICEID
322
case IEEE1284_MODE_NIBBLE:
323
case IEEE1284_MODE_BYTE:
324
return IEEE1284_PH_REV_IDLE;
326
return IEEE1284_PH_FWD_IDLE;
329
static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
331
unsigned int minor = iminor(file->f_path.dentry->d_inode);
332
struct pp_struct *pp = file->private_data;
333
struct parport * port;
334
void __user *argp = (void __user *)arg;
336
/* First handle the cases that don't take arguments. */
340
struct ieee1284_info *info;
343
if (pp->flags & PP_CLAIMED) {
344
pr_debug(CHRDEV "%x: you've already got it!\n", minor);
348
/* Deferred device registration. */
350
int err = register_device (minor, pp);
356
ret = parport_claim_or_block (pp->pdev);
360
pp->flags |= PP_CLAIMED;
362
/* For interrupt-reporting to work, we need to be
363
* informed of each interrupt. */
366
/* We may need to fix up the state machine. */
367
info = &pp->pdev->port->ieee1284;
368
pp->saved_state.mode = info->mode;
369
pp->saved_state.phase = info->phase;
370
info->mode = pp->state.mode;
371
info->phase = pp->state.phase;
372
pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
373
parport_set_timeout (pp->pdev, pp->default_inactivity);
379
pr_debug(CHRDEV "%x: too late for PPEXCL; "
380
"already registered\n", minor);
381
if (pp->flags & PP_EXCL)
382
/* But it's not really an error. */
384
/* There's no chance of making the driver happy. */
388
/* Just remember to register the device exclusively
389
* when we finally do the registration. */
390
pp->flags |= PP_EXCL;
395
if (copy_from_user (&mode, argp, sizeof (mode)))
397
/* FIXME: validate mode */
398
pp->state.mode = mode;
399
pp->state.phase = init_phase (mode);
401
if (pp->flags & PP_CLAIMED) {
402
pp->pdev->port->ieee1284.mode = mode;
403
pp->pdev->port->ieee1284.phase = pp->state.phase;
412
if (pp->flags & PP_CLAIMED) {
413
mode = pp->pdev->port->ieee1284.mode;
415
mode = pp->state.mode;
417
if (copy_to_user (argp, &mode, sizeof (mode))) {
425
if (copy_from_user (&phase, argp, sizeof (phase))) {
428
/* FIXME: validate phase */
429
pp->state.phase = phase;
431
if (pp->flags & PP_CLAIMED) {
432
pp->pdev->port->ieee1284.phase = phase;
441
if (pp->flags & PP_CLAIMED) {
442
phase = pp->pdev->port->ieee1284.phase;
444
phase = pp->state.phase;
446
if (copy_to_user (argp, &phase, sizeof (phase))) {
455
port = parport_find_number (minor);
460
parport_put_port(port);
461
if (copy_to_user (argp, &modes, sizeof (modes))) {
470
if (copy_from_user (&uflags, argp, sizeof (uflags))) {
473
pp->flags &= ~PP_FLAGMASK;
474
pp->flags |= (uflags & PP_FLAGMASK);
481
uflags = pp->flags & PP_FLAGMASK;
482
if (copy_to_user (argp, &uflags, sizeof (uflags))) {
489
/* Everything else requires the port to be claimed, so check
491
if ((pp->flags & PP_CLAIMED) == 0) {
492
pr_debug(CHRDEV "%x: claim the port first\n", minor);
496
port = pp->pdev->port;
498
struct ieee1284_info *info;
503
struct timeval par_timeout;
507
reg = parport_read_status (port);
508
if (copy_to_user (argp, ®, sizeof (reg)))
512
reg = parport_read_data (port);
513
if (copy_to_user (argp, ®, sizeof (reg)))
517
reg = parport_read_control (port);
518
if (copy_to_user (argp, ®, sizeof (reg)))
522
parport_yield_blocking (pp->pdev);
526
/* Save the state machine's state. */
527
info = &pp->pdev->port->ieee1284;
528
pp->state.mode = info->mode;
529
pp->state.phase = info->phase;
530
info->mode = pp->saved_state.mode;
531
info->phase = pp->saved_state.phase;
532
parport_release (pp->pdev);
533
pp->flags &= ~PP_CLAIMED;
537
if (copy_from_user (®, argp, sizeof (reg)))
539
parport_write_control (port, reg);
543
if (copy_from_user (®, argp, sizeof (reg)))
545
parport_write_data (port, reg);
549
if (copy_from_user (&mask, argp,
552
if (copy_from_user (®, 1 + (unsigned char __user *) arg,
555
parport_frob_control (port, mask, reg);
559
if (copy_from_user (&mode, argp, sizeof (mode)))
562
port->ops->data_reverse (port);
564
port->ops->data_forward (port);
568
if (copy_from_user (&mode, argp, sizeof (mode)))
570
switch ((ret = parport_negotiate (port, mode))) {
572
case -1: /* handshake failed, peripheral not IEEE 1284 */
575
case 1: /* handshake succeeded, peripheral rejected mode */
583
if (copy_from_user (®, argp, sizeof (reg)))
586
/* Remember what to set the control lines to, for next
587
* time we get an interrupt. */
593
ret = atomic_read (&pp->irqc);
594
if (copy_to_user (argp, &ret, sizeof (ret)))
596
atomic_sub (ret, &pp->irqc);
600
if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
603
/* Convert to jiffies, place in pp->pdev->timeout */
604
if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
607
to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
608
to_jiffies += par_timeout.tv_sec * (long)HZ;
609
if (to_jiffies <= 0) {
612
pp->pdev->timeout = to_jiffies;
616
to_jiffies = pp->pdev->timeout;
617
memset(&par_timeout, 0, sizeof(par_timeout));
618
par_timeout.tv_sec = to_jiffies / HZ;
619
par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
620
if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
625
pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
629
/* Keep the compiler happy */
633
static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
636
mutex_lock(&pp_do_mutex);
637
ret = pp_do_ioctl(file, cmd, arg);
638
mutex_unlock(&pp_do_mutex);
642
static int pp_open (struct inode * inode, struct file * file)
644
unsigned int minor = iminor(inode);
645
struct pp_struct *pp;
647
if (minor >= PARPORT_MAX)
650
pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
654
pp->state.mode = IEEE1284_MODE_COMPAT;
655
pp->state.phase = init_phase (pp->state.mode);
658
atomic_set (&pp->irqc, 0);
659
init_waitqueue_head (&pp->irq_wait);
661
/* Defer the actual device registration until the first claim.
662
* That way, we know whether or not the driver wants to have
663
* exclusive access to the port (PPEXCL).
666
file->private_data = pp;
671
static int pp_release (struct inode * inode, struct file * file)
673
unsigned int minor = iminor(inode);
674
struct pp_struct *pp = file->private_data;
678
if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
679
(pp->state.mode != IEEE1284_MODE_COMPAT)) {
680
struct ieee1284_info *info;
682
/* parport released, but not in compatibility mode */
683
parport_claim_or_block (pp->pdev);
684
pp->flags |= PP_CLAIMED;
685
info = &pp->pdev->port->ieee1284;
686
pp->saved_state.mode = info->mode;
687
pp->saved_state.phase = info->phase;
688
info->mode = pp->state.mode;
689
info->phase = pp->state.phase;
691
} else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
692
(pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
696
parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
697
pr_debug(CHRDEV "%x: negotiated back to compatibility "
698
"mode because user-space forgot\n", minor);
701
if (pp->flags & PP_CLAIMED) {
702
struct ieee1284_info *info;
704
info = &pp->pdev->port->ieee1284;
705
pp->state.mode = info->mode;
706
pp->state.phase = info->phase;
707
info->mode = pp->saved_state.mode;
708
info->phase = pp->saved_state.phase;
709
parport_release (pp->pdev);
710
if (compat_negot != 1) {
711
pr_debug(CHRDEV "%x: released pardevice "
712
"because user-space forgot\n", minor);
717
const char *name = pp->pdev->name;
718
parport_unregister_device (pp->pdev);
721
pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
729
/* No kernel lock held - fine */
730
static unsigned int pp_poll (struct file * file, poll_table * wait)
732
struct pp_struct *pp = file->private_data;
733
unsigned int mask = 0;
735
poll_wait (file, &pp->irq_wait, wait);
736
if (atomic_read (&pp->irqc))
737
mask |= POLLIN | POLLRDNORM;
742
static struct class *ppdev_class;
744
static const struct file_operations pp_fops = {
745
.owner = THIS_MODULE,
750
.unlocked_ioctl = pp_ioctl,
752
.release = pp_release,
755
static void pp_attach(struct parport *port)
757
device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
758
NULL, "parport%d", port->number);
761
static void pp_detach(struct parport *port)
763
device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
766
static struct parport_driver pp_driver = {
772
static int __init ppdev_init (void)
776
if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
777
printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
781
ppdev_class = class_create(THIS_MODULE, CHRDEV);
782
if (IS_ERR(ppdev_class)) {
783
err = PTR_ERR(ppdev_class);
786
if (parport_register_driver(&pp_driver)) {
787
printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
791
printk (KERN_INFO PP_VERSION "\n");
795
class_destroy(ppdev_class);
797
unregister_chrdev(PP_MAJOR, CHRDEV);
802
static void __exit ppdev_cleanup (void)
804
/* Clean up all parport stuff */
805
parport_unregister_driver(&pp_driver);
806
class_destroy(ppdev_class);
807
unregister_chrdev (PP_MAJOR, CHRDEV);
810
module_init(ppdev_init);
811
module_exit(ppdev_cleanup);
813
MODULE_LICENSE("GPL");
814
MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);