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 = kmalloc (strlen (CHRDEV) + 3, GFP_KERNEL);
294 sprintf (name, CHRDEV "%x", minor);
296 port = parport_find_number (minor);
298 printk (KERN_WARNING "%s: no associated port!\n", name);
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);
309 printk (KERN_WARNING "%s: failed to register device!\n", name);
315 pr_debug("%s: registered pardevice\n", name);
319 static enum ieee1284_phase init_phase (int mode)
321 switch (mode & ~(IEEE1284_DEVICEID
323 case IEEE1284_MODE_NIBBLE:
324 case IEEE1284_MODE_BYTE:
325 return IEEE1284_PH_REV_IDLE;
327 return IEEE1284_PH_FWD_IDLE;
330 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
332 unsigned int minor = iminor(file->f_path.dentry->d_inode);
333 struct pp_struct *pp = file->private_data;
334 struct parport * port;
335 void __user *argp = (void __user *)arg;
337 /* First handle the cases that don't take arguments. */
341 struct ieee1284_info *info;
344 if (pp->flags & PP_CLAIMED) {
345 pr_debug(CHRDEV "%x: you've already got it!\n", minor);
349 /* Deferred device registration. */
351 int err = register_device (minor, pp);
357 ret = parport_claim_or_block (pp->pdev);
361 pp->flags |= PP_CLAIMED;
363 /* For interrupt-reporting to work, we need to be
364 * informed of each interrupt. */
367 /* We may need to fix up the state machine. */
368 info = &pp->pdev->port->ieee1284;
369 pp->saved_state.mode = info->mode;
370 pp->saved_state.phase = info->phase;
371 info->mode = pp->state.mode;
372 info->phase = pp->state.phase;
373 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
374 parport_set_timeout (pp->pdev, pp->default_inactivity);
380 pr_debug(CHRDEV "%x: too late for PPEXCL; "
381 "already registered\n", minor);
382 if (pp->flags & PP_EXCL)
383 /* But it's not really an error. */
385 /* There's no chance of making the driver happy. */
389 /* Just remember to register the device exclusively
390 * when we finally do the registration. */
391 pp->flags |= PP_EXCL;
396 if (copy_from_user (&mode, argp, sizeof (mode)))
398 /* FIXME: validate mode */
399 pp->state.mode = mode;
400 pp->state.phase = init_phase (mode);
402 if (pp->flags & PP_CLAIMED) {
403 pp->pdev->port->ieee1284.mode = mode;
404 pp->pdev->port->ieee1284.phase = pp->state.phase;
413 if (pp->flags & PP_CLAIMED) {
414 mode = pp->pdev->port->ieee1284.mode;
416 mode = pp->state.mode;
418 if (copy_to_user (argp, &mode, sizeof (mode))) {
426 if (copy_from_user (&phase, argp, sizeof (phase))) {
429 /* FIXME: validate phase */
430 pp->state.phase = phase;
432 if (pp->flags & PP_CLAIMED) {
433 pp->pdev->port->ieee1284.phase = phase;
442 if (pp->flags & PP_CLAIMED) {
443 phase = pp->pdev->port->ieee1284.phase;
445 phase = pp->state.phase;
447 if (copy_to_user (argp, &phase, sizeof (phase))) {
456 port = parport_find_number (minor);
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 par_timeout.tv_sec = to_jiffies / HZ;
618 par_timeout.tv_usec = (to_jiffies % (long)HZ) * (1000000/HZ);
619 if (copy_to_user (argp, &par_timeout, sizeof(struct timeval)))
624 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
628 /* Keep the compiler happy */
632 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
636 ret = pp_do_ioctl(file, cmd, arg);
641 static int pp_open (struct inode * inode, struct file * file)
643 unsigned int minor = iminor(inode);
644 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);