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/smp_lock.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 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 __user * buf, size_t count,
109 unsigned int minor = iminor(file->f_path.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 pr_debug(CHRDEV "%x: claim the port first\n", minor);
126 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
130 pport = pp->pdev->port;
131 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
133 parport_set_timeout (pp->pdev,
134 (file->f_flags & O_NONBLOCK) ?
135 PARPORT_INACTIVITY_O_NONBLOCK :
136 pp->default_inactivity);
138 while (bytes_read == 0) {
139 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
141 if (mode == IEEE1284_MODE_EPP) {
142 /* various specials for EPP mode */
144 size_t (*fn)(struct parport *, void *, size_t, int);
146 if (pp->flags & PP_W91284PIC) {
147 flags |= PARPORT_W91284PIC;
149 if (pp->flags & PP_FASTREAD) {
150 flags |= PARPORT_EPP_FAST;
152 if (pport->ieee1284.mode & IEEE1284_ADDR) {
153 fn = pport->ops->epp_read_addr;
155 fn = pport->ops->epp_read_data;
157 bytes_read = (*fn)(pport, kbuffer, need, flags);
159 bytes_read = parport_read (pport, kbuffer, need);
165 if (file->f_flags & O_NONBLOCK) {
166 bytes_read = -EAGAIN;
170 if (signal_pending (current)) {
171 bytes_read = -ERESTARTSYS;
178 parport_set_timeout (pp->pdev, pp->default_inactivity);
180 if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
181 bytes_read = -EFAULT;
188 static ssize_t pp_write (struct file * file, const char __user * buf,
189 size_t count, loff_t * ppos)
191 unsigned int minor = iminor(file->f_path.dentry->d_inode);
192 struct pp_struct *pp = file->private_data;
194 ssize_t bytes_written = 0;
197 struct parport *pport;
199 if (!(pp->flags & PP_CLAIMED)) {
200 /* Don't have the port claimed */
201 pr_debug(CHRDEV "%x: claim the port first\n", minor);
205 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
209 pport = pp->pdev->port;
210 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
212 parport_set_timeout (pp->pdev,
213 (file->f_flags & O_NONBLOCK) ?
214 PARPORT_INACTIVITY_O_NONBLOCK :
215 pp->default_inactivity);
217 while (bytes_written < count) {
218 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
220 if (copy_from_user (kbuffer, buf + bytes_written, n)) {
221 bytes_written = -EFAULT;
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);
231 wrote = pport->ops->epp_write_data (pport,
232 kbuffer, n, PARPORT_EPP_FAST);
235 wrote = parport_write (pp->pdev->port, kbuffer, n);
239 if (!bytes_written) {
240 bytes_written = wrote;
245 bytes_written += wrote;
247 if (file->f_flags & O_NONBLOCK) {
249 bytes_written = -EAGAIN;
253 if (signal_pending (current)) {
254 if (!bytes_written) {
255 bytes_written = -EINTR;
263 parport_set_timeout (pp->pdev, pp->default_inactivity);
267 return bytes_written;
270 static void pp_irq (void *private)
272 struct pp_struct *pp = private;
274 if (pp->irqresponse) {
275 parport_write_control (pp->pdev->port, pp->irqctl);
279 atomic_inc (&pp->irqc);
280 wake_up_interruptible (&pp->irq_wait);
283 static int register_device (int minor, struct pp_struct *pp)
285 struct parport *port;
286 struct pardevice * pdev = NULL;
290 name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
294 port = parport_find_number (minor);
296 printk (KERN_WARNING "%s: no associated port!\n", name);
301 fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
302 pdev = parport_register_device (port, name, NULL,
303 NULL, pp_irq, fl, pp);
304 parport_put_port (port);
307 printk (KERN_WARNING "%s: failed to register device!\n", name);
313 pr_debug("%s: registered pardevice\n", name);
317 static enum ieee1284_phase init_phase (int mode)
319 switch (mode & ~(IEEE1284_DEVICEID
321 case IEEE1284_MODE_NIBBLE:
322 case IEEE1284_MODE_BYTE:
323 return IEEE1284_PH_REV_IDLE;
325 return IEEE1284_PH_FWD_IDLE;
328 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
330 unsigned int minor = iminor(file->f_path.dentry->d_inode);
331 struct pp_struct *pp = file->private_data;
332 struct parport * port;
333 void __user *argp = (void __user *)arg;
335 /* First handle the cases that don't take arguments. */
339 struct ieee1284_info *info;
342 if (pp->flags & PP_CLAIMED) {
343 pr_debug(CHRDEV "%x: you've already got it!\n", minor);
347 /* Deferred device registration. */
349 int err = register_device (minor, pp);
355 ret = parport_claim_or_block (pp->pdev);
359 pp->flags |= PP_CLAIMED;
361 /* For interrupt-reporting to work, we need to be
362 * informed of each interrupt. */
365 /* We may need to fix up the state machine. */
366 info = &pp->pdev->port->ieee1284;
367 pp->saved_state.mode = info->mode;
368 pp->saved_state.phase = info->phase;
369 info->mode = pp->state.mode;
370 info->phase = pp->state.phase;
371 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
372 parport_set_timeout (pp->pdev, pp->default_inactivity);
378 pr_debug(CHRDEV "%x: too late for PPEXCL; "
379 "already registered\n", minor);
380 if (pp->flags & PP_EXCL)
381 /* But it's not really an error. */
383 /* There's no chance of making the driver happy. */
387 /* Just remember to register the device exclusively
388 * when we finally do the registration. */
389 pp->flags |= PP_EXCL;
394 if (copy_from_user (&mode, argp, sizeof (mode)))
396 /* FIXME: validate mode */
397 pp->state.mode = mode;
398 pp->state.phase = init_phase (mode);
400 if (pp->flags & PP_CLAIMED) {
401 pp->pdev->port->ieee1284.mode = mode;
402 pp->pdev->port->ieee1284.phase = pp->state.phase;
411 if (pp->flags & PP_CLAIMED) {
412 mode = pp->pdev->port->ieee1284.mode;
414 mode = pp->state.mode;
416 if (copy_to_user (argp, &mode, sizeof (mode))) {
424 if (copy_from_user (&phase, argp, sizeof (phase))) {
427 /* FIXME: validate phase */
428 pp->state.phase = phase;
430 if (pp->flags & PP_CLAIMED) {
431 pp->pdev->port->ieee1284.phase = phase;
440 if (pp->flags & PP_CLAIMED) {
441 phase = pp->pdev->port->ieee1284.phase;
443 phase = pp->state.phase;
445 if (copy_to_user (argp, &phase, sizeof (phase))) {
454 port = parport_find_number (minor);
459 if (copy_to_user (argp, &modes, sizeof (modes))) {
468 if (copy_from_user (&uflags, argp, sizeof (uflags))) {
471 pp->flags &= ~PP_FLAGMASK;
472 pp->flags |= (uflags & PP_FLAGMASK);
479 uflags = pp->flags & PP_FLAGMASK;
480 if (copy_to_user (argp, &uflags, sizeof (uflags))) {
487 /* Everything else requires the port to be claimed, so check
489 if ((pp->flags & PP_CLAIMED) == 0) {
490 pr_debug(CHRDEV "%x: claim the port first\n", minor);
494 port = pp->pdev->port;
496 struct ieee1284_info *info;
501 struct timeval par_timeout;
505 reg = parport_read_status (port);
506 if (copy_to_user (argp, ®, sizeof (reg)))
510 reg = parport_read_data (port);
511 if (copy_to_user (argp, ®, sizeof (reg)))
515 reg = parport_read_control (port);
516 if (copy_to_user (argp, ®, sizeof (reg)))
520 parport_yield_blocking (pp->pdev);
524 /* Save the state machine's state. */
525 info = &pp->pdev->port->ieee1284;
526 pp->state.mode = info->mode;
527 pp->state.phase = info->phase;
528 info->mode = pp->saved_state.mode;
529 info->phase = pp->saved_state.phase;
530 parport_release (pp->pdev);
531 pp->flags &= ~PP_CLAIMED;
535 if (copy_from_user (®, argp, sizeof (reg)))
537 parport_write_control (port, reg);
541 if (copy_from_user (®, argp, sizeof (reg)))
543 parport_write_data (port, reg);
547 if (copy_from_user (&mask, argp,
550 if (copy_from_user (®, 1 + (unsigned char __user *) arg,
553 parport_frob_control (port, mask, reg);
557 if (copy_from_user (&mode, argp, sizeof (mode)))
560 port->ops->data_reverse (port);
562 port->ops->data_forward (port);
566 if (copy_from_user (&mode, argp, sizeof (mode)))
568 switch ((ret = parport_negotiate (port, mode))) {
570 case -1: /* handshake failed, peripheral not IEEE 1284 */
573 case 1: /* handshake succeeded, peripheral rejected mode */
581 if (copy_from_user (®, argp, sizeof (reg)))
584 /* Remember what to set the control lines to, for next
585 * time we get an interrupt. */
591 ret = atomic_read (&pp->irqc);
592 if (copy_to_user (argp, &ret, sizeof (ret)))
594 atomic_sub (ret, &pp->irqc);
598 if (copy_from_user (&par_timeout, argp, sizeof(struct timeval))) {
601 /* Convert to jiffies, place in pp->pdev->timeout */
602 if ((par_timeout.tv_sec < 0) || (par_timeout.tv_usec < 0)) {
605 to_jiffies = ROUND_UP(par_timeout.tv_usec, 1000000/HZ);
606 to_jiffies += par_timeout.tv_sec * (long)HZ;
607 if (to_jiffies <= 0) {
610 pp->pdev->timeout = to_jiffies;
614 to_jiffies = pp->pdev->timeout;
615 par_timeout.tv_sec = to_jiffies / HZ;
616 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
617 if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
622 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
626 /* Keep the compiler happy */
630 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
634 ret = pp_do_ioctl(file, cmd, arg);
639 static int pp_open (struct inode * inode, struct file * file)
641 unsigned int minor = iminor(inode);
642 struct pp_struct *pp;
645 if (minor >= PARPORT_MAX)
648 pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
652 pp->state.mode = IEEE1284_MODE_COMPAT;
653 pp->state.phase = init_phase (pp->state.mode);
656 atomic_set (&pp->irqc, 0);
657 init_waitqueue_head (&pp->irq_wait);
659 /* Defer the actual device registration until the first claim.
660 * That way, we know whether or not the driver wants to have
661 * exclusive access to the port (PPEXCL).
664 file->private_data = pp;
669 static int pp_release (struct inode * inode, struct file * file)
671 unsigned int minor = iminor(inode);
672 struct pp_struct *pp = file->private_data;
676 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
677 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
678 struct ieee1284_info *info;
680 /* parport released, but not in compatibility mode */
681 parport_claim_or_block (pp->pdev);
682 pp->flags |= PP_CLAIMED;
683 info = &pp->pdev->port->ieee1284;
684 pp->saved_state.mode = info->mode;
685 pp->saved_state.phase = info->phase;
686 info->mode = pp->state.mode;
687 info->phase = pp->state.phase;
689 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
690 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
694 parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
695 pr_debug(CHRDEV "%x: negotiated back to compatibility "
696 "mode because user-space forgot\n", minor);
699 if (pp->flags & PP_CLAIMED) {
700 struct ieee1284_info *info;
702 info = &pp->pdev->port->ieee1284;
703 pp->state.mode = info->mode;
704 pp->state.phase = info->phase;
705 info->mode = pp->saved_state.mode;
706 info->phase = pp->saved_state.phase;
707 parport_release (pp->pdev);
708 if (compat_negot != 1) {
709 pr_debug(CHRDEV "%x: released pardevice "
710 "because user-space forgot\n", minor);
715 const char *name = pp->pdev->name;
716 parport_unregister_device (pp->pdev);
719 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
727 /* No kernel lock held - fine */
728 static unsigned int pp_poll (struct file * file, poll_table * wait)
730 struct pp_struct *pp = file->private_data;
731 unsigned int mask = 0;
733 poll_wait (file, &pp->irq_wait, wait);
734 if (atomic_read (&pp->irqc))
735 mask |= POLLIN | POLLRDNORM;
740 static struct class *ppdev_class;
742 static const struct file_operations pp_fops = {
743 .owner = THIS_MODULE,
748 .unlocked_ioctl = pp_ioctl,
750 .release = pp_release,
753 static void pp_attach(struct parport *port)
755 device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
756 NULL, "parport%d", port->number);
759 static void pp_detach(struct parport *port)
761 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
764 static struct parport_driver pp_driver = {
770 static int __init ppdev_init (void)
774 if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
775 printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
779 ppdev_class = class_create(THIS_MODULE, CHRDEV);
780 if (IS_ERR(ppdev_class)) {
781 err = PTR_ERR(ppdev_class);
784 if (parport_register_driver(&pp_driver)) {
785 printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
789 printk (KERN_INFO PP_VERSION "\n");
793 class_destroy(ppdev_class);
795 unregister_chrdev(PP_MAJOR, CHRDEV);
800 static void __exit ppdev_cleanup (void)
802 /* Clean up all parport stuff */
803 parport_unregister_driver(&pp_driver);
804 class_destroy(ppdev_class);
805 unregister_chrdev (PP_MAJOR, CHRDEV);
808 module_init(ppdev_init);
809 module_exit(ppdev_cleanup);
811 MODULE_LICENSE("GPL");
812 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);