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/devfs_fs_kernel.h>
64 #include <linux/ioctl.h>
65 #include <linux/parport.h>
66 #include <linux/ctype.h>
67 #include <linux/poll.h>
68 #include <asm/uaccess.h>
69 #include <linux/ppdev.h>
70 #include <linux/smp_lock.h>
71 #include <linux/device.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 inline void pp_enable_irq (struct pp_struct *pp)
102 struct parport *port = pp->pdev->port;
103 port->ops->enable_irq (port);
106 static ssize_t pp_read (struct file * file, char * buf, size_t count,
109 unsigned int minor = iminor(file->f_dentry->d_inode);
110 struct pp_struct *pp = file->private_data;
112 ssize_t bytes_read = 0;
113 struct parport *pport;
116 if (!(pp->flags & PP_CLAIMED)) {
117 /* Don't have the port claimed */
118 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
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 * buf, size_t count,
192 unsigned int minor = iminor(file->f_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 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
207 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
211 pport = pp->pdev->port;
212 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
214 parport_set_timeout (pp->pdev,
215 (file->f_flags & O_NONBLOCK) ?
216 PARPORT_INACTIVITY_O_NONBLOCK :
217 pp->default_inactivity);
219 while (bytes_written < count) {
220 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
222 if (copy_from_user (kbuffer, buf + bytes_written, n)) {
223 bytes_written = -EFAULT;
227 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
228 /* do a fast EPP write */
229 if (pport->ieee1284.mode & IEEE1284_ADDR) {
230 wrote = pport->ops->epp_write_addr (pport,
231 kbuffer, n, PARPORT_EPP_FAST);
233 wrote = pport->ops->epp_write_data (pport,
234 kbuffer, n, PARPORT_EPP_FAST);
237 wrote = parport_write (pp->pdev->port, kbuffer, n);
241 if (!bytes_written) {
242 bytes_written = wrote;
247 bytes_written += wrote;
249 if (file->f_flags & O_NONBLOCK) {
251 bytes_written = -EAGAIN;
255 if (signal_pending (current)) {
256 if (!bytes_written) {
257 bytes_written = -EINTR;
265 parport_set_timeout (pp->pdev, pp->default_inactivity);
269 return bytes_written;
272 static void pp_irq (int irq, void * private, struct pt_regs * unused)
274 struct pp_struct * pp = (struct pp_struct *) private;
276 if (pp->irqresponse) {
277 parport_write_control (pp->pdev->port, pp->irqctl);
281 atomic_inc (&pp->irqc);
282 wake_up_interruptible (&pp->irq_wait);
285 static int register_device (int minor, struct pp_struct *pp)
287 struct parport *port;
288 struct pardevice * pdev = NULL;
292 name = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
296 sprintf (name, CHRDEV "%x", minor);
298 port = parport_find_number (minor);
300 printk (KERN_WARNING "%s: no associated port!\n", name);
305 fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
306 pdev = parport_register_device (port, name, NULL,
307 NULL, pp_irq, fl, pp);
308 parport_put_port (port);
311 printk (KERN_WARNING "%s: failed to register device!\n", name);
317 printk (KERN_DEBUG "%s: registered pardevice\n", name);
321 static enum ieee1284_phase init_phase (int mode)
323 switch (mode & ~(IEEE1284_DEVICEID
325 case IEEE1284_MODE_NIBBLE:
326 case IEEE1284_MODE_BYTE:
327 return IEEE1284_PH_REV_IDLE;
329 return IEEE1284_PH_FWD_IDLE;
332 static int pp_ioctl(struct inode *inode, struct file *file,
333 unsigned int cmd, unsigned long arg)
335 unsigned int minor = iminor(inode);
336 struct pp_struct *pp = file->private_data;
337 struct parport * port;
339 /* First handle the cases that don't take arguments. */
343 struct ieee1284_info *info;
346 if (pp->flags & PP_CLAIMED) {
347 printk (KERN_DEBUG CHRDEV
348 "%x: you've already got it!\n", minor);
352 /* Deferred device registration. */
354 int err = register_device (minor, pp);
360 ret = parport_claim_or_block (pp->pdev);
364 pp->flags |= PP_CLAIMED;
366 /* For interrupt-reporting to work, we need to be
367 * informed of each interrupt. */
370 /* We may need to fix up the state machine. */
371 info = &pp->pdev->port->ieee1284;
372 pp->saved_state.mode = info->mode;
373 pp->saved_state.phase = info->phase;
374 info->mode = pp->state.mode;
375 info->phase = pp->state.phase;
376 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
377 parport_set_timeout (pp->pdev, pp->default_inactivity);
383 printk (KERN_DEBUG CHRDEV "%x: too late for PPEXCL; "
384 "already registered\n", minor);
385 if (pp->flags & PP_EXCL)
386 /* But it's not really an error. */
388 /* There's no chance of making the driver happy. */
392 /* Just remember to register the device exclusively
393 * when we finally do the registration. */
394 pp->flags |= PP_EXCL;
399 if (copy_from_user (&mode, (int *) arg, sizeof (mode)))
401 /* FIXME: validate mode */
402 pp->state.mode = mode;
403 pp->state.phase = init_phase (mode);
405 if (pp->flags & PP_CLAIMED) {
406 pp->pdev->port->ieee1284.mode = mode;
407 pp->pdev->port->ieee1284.phase = pp->state.phase;
416 if (pp->flags & PP_CLAIMED) {
417 mode = pp->pdev->port->ieee1284.mode;
419 mode = pp->state.mode;
421 if (copy_to_user ((int *)arg, &mode, sizeof (mode))) {
429 if (copy_from_user (&phase, (int *) arg, sizeof (phase))) {
432 /* FIXME: validate phase */
433 pp->state.phase = phase;
435 if (pp->flags & PP_CLAIMED) {
436 pp->pdev->port->ieee1284.phase = phase;
445 if (pp->flags & PP_CLAIMED) {
446 phase = pp->pdev->port->ieee1284.phase;
448 phase = pp->state.phase;
450 if (copy_to_user ((int *)arg, &phase, sizeof (phase))) {
459 port = parport_find_number (minor);
464 if (copy_to_user ((unsigned int *)arg, &modes, sizeof (modes))) {
473 if (copy_from_user (&uflags, (int *)arg, sizeof (uflags))) {
476 pp->flags &= ~PP_FLAGMASK;
477 pp->flags |= (uflags & PP_FLAGMASK);
484 uflags = pp->flags & PP_FLAGMASK;
485 if (copy_to_user ((int *)arg, &uflags, sizeof (uflags))) {
492 /* Everything else requires the port to be claimed, so check
494 if ((pp->flags & PP_CLAIMED) == 0) {
495 printk (KERN_DEBUG CHRDEV "%x: claim the port first\n",
500 port = pp->pdev->port;
502 struct ieee1284_info *info;
507 struct timeval par_timeout;
511 reg = parport_read_status (port);
512 if (copy_to_user ((unsigned char *) arg, ®, sizeof (reg)))
516 reg = parport_read_data (port);
517 if (copy_to_user ((unsigned char *) arg, ®, sizeof (reg)))
521 reg = parport_read_control (port);
522 if (copy_to_user ((unsigned char *) arg, ®, sizeof (reg)))
526 parport_yield_blocking (pp->pdev);
530 /* Save the state machine's state. */
531 info = &pp->pdev->port->ieee1284;
532 pp->state.mode = info->mode;
533 pp->state.phase = info->phase;
534 info->mode = pp->saved_state.mode;
535 info->phase = pp->saved_state.phase;
536 parport_release (pp->pdev);
537 pp->flags &= ~PP_CLAIMED;
541 if (copy_from_user (®, (unsigned char *) arg, sizeof (reg)))
543 parport_write_control (port, reg);
547 if (copy_from_user (®, (unsigned char *) arg, sizeof (reg)))
549 parport_write_data (port, reg);
553 if (copy_from_user (&mask, (unsigned char *) arg,
556 if (copy_from_user (®, 1 + (unsigned char *) arg,
559 parport_frob_control (port, mask, reg);
563 if (copy_from_user (&mode, (int *) arg, sizeof (mode)))
566 port->ops->data_reverse (port);
568 port->ops->data_forward (port);
572 if (copy_from_user (&mode, (int *) arg, sizeof (mode)))
574 switch ((ret = parport_negotiate (port, mode))) {
576 case -1: /* handshake failed, peripheral not IEEE 1284 */
579 case 1: /* handshake succeeded, peripheral rejected mode */
587 if (copy_from_user (®, (unsigned char *) arg,
591 /* Remember what to set the control lines to, for next
592 * time we get an interrupt. */
598 ret = atomic_read (&pp->irqc);
599 if (copy_to_user ((int *) arg, &ret, sizeof (ret)))
601 atomic_sub (ret, &pp->irqc);
605 if (copy_from_user (&par_timeout, (struct timeval *)arg,
606 sizeof(struct timeval))) {
609 /* Convert to jiffies, place in pp->pdev->timeout */
610 if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
613 to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
614 to_jiffies += par_timeout.tv_sec * (long)HZ;
615 if (to_jiffies <= 0) {
618 pp->pdev->timeout = to_jiffies;
622 to_jiffies = pp->pdev->timeout;
623 par_timeout.tv_sec = to_jiffies / HZ;
624 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
625 if (copy_to_user ((struct timeval *)arg, &par_timeout,
626 sizeof(struct timeval))) {
632 printk (KERN_DEBUG CHRDEV "%x: What? (cmd=0x%x)\n", minor,
637 /* Keep the compiler happy */
641 static int pp_open (struct inode * inode, struct file * file)
643 unsigned int minor = iminor(inode);
644 struct pp_struct *pp;
646 if (minor >= PARPORT_MAX)
649 pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
653 pp->state.mode = IEEE1284_MODE_COMPAT;
654 pp->state.phase = init_phase (pp->state.mode);
657 atomic_set (&pp->irqc, 0);
658 init_waitqueue_head (&pp->irq_wait);
660 /* Defer the actual device registration until the first claim.
661 * That way, we know whether or not the driver wants to have
662 * exclusive access to the port (PPEXCL).
665 file->private_data = pp;
670 static int pp_release (struct inode * inode, struct file * file)
672 unsigned int minor = iminor(inode);
673 struct pp_struct *pp = file->private_data;
677 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
678 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
679 struct ieee1284_info *info;
681 /* parport released, but not in compatibility mode */
682 parport_claim_or_block (pp->pdev);
683 pp->flags |= PP_CLAIMED;
684 info = &pp->pdev->port->ieee1284;
685 pp->saved_state.mode = info->mode;
686 pp->saved_state.phase = info->phase;
687 info->mode = pp->state.mode;
688 info->phase = pp->state.phase;
690 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
691 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
695 parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
696 printk (KERN_DEBUG CHRDEV
697 "%x: negotiated back to compatibility mode because "
698 "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 printk (KERN_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 printk (KERN_DEBUG CHRDEV "%x: unregistered pardevice\n",
730 /* No kernel lock held - fine */
731 static unsigned int pp_poll (struct file * file, poll_table * wait)
733 struct pp_struct *pp = file->private_data;
734 unsigned int mask = 0;
736 poll_wait (file, &pp->irq_wait, wait);
737 if (atomic_read (&pp->irqc))
738 mask |= POLLIN | POLLRDNORM;
743 static struct class_simple *ppdev_class;
745 static struct file_operations pp_fops = {
746 .owner = THIS_MODULE,
753 .release = pp_release,
756 static void pp_attach(struct parport *port)
758 class_simple_device_add(ppdev_class, MKDEV(PP_MAJOR, port->number),
759 NULL, "parport%d", port->number);
762 static void pp_detach(struct parport *port)
764 class_simple_device_remove(MKDEV(PP_MAJOR, port->number));
767 static struct parport_driver pp_driver = {
773 static int __init ppdev_init (void)
777 if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
778 printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
782 ppdev_class = class_simple_create(THIS_MODULE, CHRDEV);
783 if (IS_ERR(ppdev_class)) {
784 err = PTR_ERR(ppdev_class);
787 devfs_mk_dir("parports");
788 for (i = 0; i < PARPORT_MAX; i++) {
789 devfs_mk_cdev(MKDEV(PP_MAJOR, i),
790 S_IFCHR | S_IRUGO | S_IWUGO, "parports/%d", i);
792 if (parport_register_driver(&pp_driver)) {
793 printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
797 printk (KERN_INFO PP_VERSION "\n");
801 for (i = 0; i < PARPORT_MAX; i++)
802 devfs_remove("parports/%d", i);
803 devfs_remove("parports");
804 class_simple_destroy(ppdev_class);
806 unregister_chrdev(PP_MAJOR, CHRDEV);
811 static void __exit ppdev_cleanup (void)
814 /* Clean up all parport stuff */
815 for (i = 0; i < PARPORT_MAX; i++)
816 devfs_remove("parports/%d", i);
817 parport_unregister_driver(&pp_driver);
818 devfs_remove("parports");
819 class_simple_destroy(ppdev_class);
820 unregister_chrdev (PP_MAJOR, CHRDEV);
823 module_init(ppdev_init);
824 module_exit(ppdev_cleanup);
826 MODULE_LICENSE("GPL");
827 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);