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>
72 #include <linux/compat.h>
74 #define PP_VERSION "ppdev: user-space parallel port driver"
75 #define CHRDEV "ppdev"
78 struct pardevice * pdev;
79 wait_queue_head_t irq_wait;
84 struct ieee1284_info state;
85 struct ieee1284_info saved_state;
86 long default_inactivity;
89 /* pp_struct.flags bitfields */
90 #define PP_CLAIMED (1<<0)
91 #define PP_EXCL (1<<1)
94 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
95 #define PP_BUFFER_SIZE 1024
96 #define PARDEVICE_MAX 8
98 /* ROUND_UP macro from fs/select.c */
99 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
101 static DEFINE_MUTEX(pp_do_mutex);
103 /* define fixed sized ioctl cmd for y2038 migration */
104 #define PPGETTIME32 _IOR(PP_IOCTL, 0x95, s32[2])
105 #define PPSETTIME32 _IOW(PP_IOCTL, 0x96, s32[2])
106 #define PPGETTIME64 _IOR(PP_IOCTL, 0x95, s64[2])
107 #define PPSETTIME64 _IOW(PP_IOCTL, 0x96, s64[2])
109 static inline void pp_enable_irq (struct pp_struct *pp)
111 struct parport *port = pp->pdev->port;
112 port->ops->enable_irq (port);
115 static ssize_t pp_read (struct file * file, char __user * buf, size_t count,
118 unsigned int minor = iminor(file_inode(file));
119 struct pp_struct *pp = file->private_data;
121 ssize_t bytes_read = 0;
122 struct parport *pport;
125 if (!(pp->flags & PP_CLAIMED)) {
126 /* Don't have the port claimed */
127 pr_debug(CHRDEV "%x: claim the port first\n", minor);
135 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
139 pport = pp->pdev->port;
140 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
142 parport_set_timeout (pp->pdev,
143 (file->f_flags & O_NONBLOCK) ?
144 PARPORT_INACTIVITY_O_NONBLOCK :
145 pp->default_inactivity);
147 while (bytes_read == 0) {
148 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
150 if (mode == IEEE1284_MODE_EPP) {
151 /* various specials for EPP mode */
153 size_t (*fn)(struct parport *, void *, size_t, int);
155 if (pp->flags & PP_W91284PIC) {
156 flags |= PARPORT_W91284PIC;
158 if (pp->flags & PP_FASTREAD) {
159 flags |= PARPORT_EPP_FAST;
161 if (pport->ieee1284.mode & IEEE1284_ADDR) {
162 fn = pport->ops->epp_read_addr;
164 fn = pport->ops->epp_read_data;
166 bytes_read = (*fn)(pport, kbuffer, need, flags);
168 bytes_read = parport_read (pport, kbuffer, need);
174 if (file->f_flags & O_NONBLOCK) {
175 bytes_read = -EAGAIN;
179 if (signal_pending (current)) {
180 bytes_read = -ERESTARTSYS;
187 parport_set_timeout (pp->pdev, pp->default_inactivity);
189 if (bytes_read > 0 && copy_to_user (buf, kbuffer, bytes_read))
190 bytes_read = -EFAULT;
197 static ssize_t pp_write (struct file * file, const char __user * buf,
198 size_t count, loff_t * ppos)
200 unsigned int minor = iminor(file_inode(file));
201 struct pp_struct *pp = file->private_data;
203 ssize_t bytes_written = 0;
206 struct parport *pport;
208 if (!(pp->flags & PP_CLAIMED)) {
209 /* Don't have the port claimed */
210 pr_debug(CHRDEV "%x: claim the port first\n", minor);
214 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
218 pport = pp->pdev->port;
219 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
221 parport_set_timeout (pp->pdev,
222 (file->f_flags & O_NONBLOCK) ?
223 PARPORT_INACTIVITY_O_NONBLOCK :
224 pp->default_inactivity);
226 while (bytes_written < count) {
227 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
229 if (copy_from_user (kbuffer, buf + bytes_written, n)) {
230 bytes_written = -EFAULT;
234 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
235 /* do a fast EPP write */
236 if (pport->ieee1284.mode & IEEE1284_ADDR) {
237 wrote = pport->ops->epp_write_addr (pport,
238 kbuffer, n, PARPORT_EPP_FAST);
240 wrote = pport->ops->epp_write_data (pport,
241 kbuffer, n, PARPORT_EPP_FAST);
244 wrote = parport_write (pp->pdev->port, kbuffer, n);
248 if (!bytes_written) {
249 bytes_written = wrote;
254 bytes_written += wrote;
256 if (file->f_flags & O_NONBLOCK) {
258 bytes_written = -EAGAIN;
262 if (signal_pending (current))
268 parport_set_timeout (pp->pdev, pp->default_inactivity);
272 return bytes_written;
275 static void pp_irq (void *private)
277 struct pp_struct *pp = private;
279 if (pp->irqresponse) {
280 parport_write_control (pp->pdev->port, pp->irqctl);
284 atomic_inc (&pp->irqc);
285 wake_up_interruptible (&pp->irq_wait);
288 static int register_device (int minor, struct pp_struct *pp)
290 struct parport *port;
291 struct pardevice * pdev = NULL;
295 name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
299 port = parport_find_number (minor);
301 printk (KERN_WARNING "%s: no associated port!\n", name);
306 fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
307 pdev = parport_register_device (port, name, NULL,
308 NULL, pp_irq, fl, pp);
309 parport_put_port (port);
312 printk (KERN_WARNING "%s: failed to register device!\n", name);
318 pr_debug("%s: registered pardevice\n", name);
322 static enum ieee1284_phase init_phase (int mode)
324 switch (mode & ~(IEEE1284_DEVICEID
326 case IEEE1284_MODE_NIBBLE:
327 case IEEE1284_MODE_BYTE:
328 return IEEE1284_PH_REV_IDLE;
330 return IEEE1284_PH_FWD_IDLE;
333 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
337 if ((tv_sec < 0) || (tv_usec < 0))
340 to_jiffies = usecs_to_jiffies(tv_usec);
341 to_jiffies += tv_sec * HZ;
345 pdev->timeout = to_jiffies;
349 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
351 unsigned int minor = iminor(file_inode(file));
352 struct pp_struct *pp = file->private_data;
353 struct parport * port;
354 void __user *argp = (void __user *)arg;
356 /* First handle the cases that don't take arguments. */
360 struct ieee1284_info *info;
363 if (pp->flags & PP_CLAIMED) {
364 pr_debug(CHRDEV "%x: you've already got it!\n", minor);
368 /* Deferred device registration. */
370 int err = register_device (minor, pp);
376 ret = parport_claim_or_block (pp->pdev);
380 pp->flags |= PP_CLAIMED;
382 /* For interrupt-reporting to work, we need to be
383 * informed of each interrupt. */
386 /* We may need to fix up the state machine. */
387 info = &pp->pdev->port->ieee1284;
388 pp->saved_state.mode = info->mode;
389 pp->saved_state.phase = info->phase;
390 info->mode = pp->state.mode;
391 info->phase = pp->state.phase;
392 pp->default_inactivity = parport_set_timeout (pp->pdev, 0);
393 parport_set_timeout (pp->pdev, pp->default_inactivity);
399 pr_debug(CHRDEV "%x: too late for PPEXCL; "
400 "already registered\n", minor);
401 if (pp->flags & PP_EXCL)
402 /* But it's not really an error. */
404 /* There's no chance of making the driver happy. */
408 /* Just remember to register the device exclusively
409 * when we finally do the registration. */
410 pp->flags |= PP_EXCL;
415 if (copy_from_user (&mode, argp, sizeof (mode)))
417 /* FIXME: validate mode */
418 pp->state.mode = mode;
419 pp->state.phase = init_phase (mode);
421 if (pp->flags & PP_CLAIMED) {
422 pp->pdev->port->ieee1284.mode = mode;
423 pp->pdev->port->ieee1284.phase = pp->state.phase;
432 if (pp->flags & PP_CLAIMED) {
433 mode = pp->pdev->port->ieee1284.mode;
435 mode = pp->state.mode;
437 if (copy_to_user (argp, &mode, sizeof (mode))) {
445 if (copy_from_user (&phase, argp, sizeof (phase))) {
448 /* FIXME: validate phase */
449 pp->state.phase = phase;
451 if (pp->flags & PP_CLAIMED) {
452 pp->pdev->port->ieee1284.phase = phase;
461 if (pp->flags & PP_CLAIMED) {
462 phase = pp->pdev->port->ieee1284.phase;
464 phase = pp->state.phase;
466 if (copy_to_user (argp, &phase, sizeof (phase))) {
475 port = parport_find_number (minor);
480 parport_put_port(port);
481 if (copy_to_user (argp, &modes, sizeof (modes))) {
490 if (copy_from_user (&uflags, argp, sizeof (uflags))) {
493 pp->flags &= ~PP_FLAGMASK;
494 pp->flags |= (uflags & PP_FLAGMASK);
501 uflags = pp->flags & PP_FLAGMASK;
502 if (copy_to_user (argp, &uflags, sizeof (uflags))) {
509 /* Everything else requires the port to be claimed, so check
511 if ((pp->flags & PP_CLAIMED) == 0) {
512 pr_debug(CHRDEV "%x: claim the port first\n", minor);
516 port = pp->pdev->port;
518 struct ieee1284_info *info;
524 struct timespec64 ts;
528 reg = parport_read_status (port);
529 if (copy_to_user (argp, ®, sizeof (reg)))
533 reg = parport_read_data (port);
534 if (copy_to_user (argp, ®, sizeof (reg)))
538 reg = parport_read_control (port);
539 if (copy_to_user (argp, ®, sizeof (reg)))
543 parport_yield_blocking (pp->pdev);
547 /* Save the state machine's state. */
548 info = &pp->pdev->port->ieee1284;
549 pp->state.mode = info->mode;
550 pp->state.phase = info->phase;
551 info->mode = pp->saved_state.mode;
552 info->phase = pp->saved_state.phase;
553 parport_release (pp->pdev);
554 pp->flags &= ~PP_CLAIMED;
558 if (copy_from_user (®, argp, sizeof (reg)))
560 parport_write_control (port, reg);
564 if (copy_from_user (®, argp, sizeof (reg)))
566 parport_write_data (port, reg);
570 if (copy_from_user (&mask, argp,
573 if (copy_from_user (®, 1 + (unsigned char __user *) arg,
576 parport_frob_control (port, mask, reg);
580 if (copy_from_user (&mode, argp, sizeof (mode)))
583 port->ops->data_reverse (port);
585 port->ops->data_forward (port);
589 if (copy_from_user (&mode, argp, sizeof (mode)))
591 switch ((ret = parport_negotiate (port, mode))) {
593 case -1: /* handshake failed, peripheral not IEEE 1284 */
596 case 1: /* handshake succeeded, peripheral rejected mode */
604 if (copy_from_user (®, argp, sizeof (reg)))
607 /* Remember what to set the control lines to, for next
608 * time we get an interrupt. */
614 ret = atomic_read (&pp->irqc);
615 if (copy_to_user (argp, &ret, sizeof (ret)))
617 atomic_sub (ret, &pp->irqc);
621 if (copy_from_user(time32, argp, sizeof(time32)))
624 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
627 if (copy_from_user(time64, argp, sizeof(time64)))
630 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
633 jiffies_to_timespec64(pp->pdev->timeout, &ts);
634 time32[0] = ts.tv_sec;
635 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
636 if ((time32[0] < 0) || (time32[1] < 0))
639 if (copy_to_user(argp, time32, sizeof(time32)))
645 jiffies_to_timespec64(pp->pdev->timeout, &ts);
646 time64[0] = ts.tv_sec;
647 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
648 if ((time64[0] < 0) || (time64[1] < 0))
651 if (copy_to_user(argp, time64, sizeof(time64)))
657 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
661 /* Keep the compiler happy */
665 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
668 mutex_lock(&pp_do_mutex);
669 ret = pp_do_ioctl(file, cmd, arg);
670 mutex_unlock(&pp_do_mutex);
675 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
678 return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
682 static int pp_open (struct inode * inode, struct file * file)
684 unsigned int minor = iminor(inode);
685 struct pp_struct *pp;
687 if (minor >= PARPORT_MAX)
690 pp = kmalloc (sizeof (struct pp_struct), GFP_KERNEL);
694 pp->state.mode = IEEE1284_MODE_COMPAT;
695 pp->state.phase = init_phase (pp->state.mode);
698 atomic_set (&pp->irqc, 0);
699 init_waitqueue_head (&pp->irq_wait);
701 /* Defer the actual device registration until the first claim.
702 * That way, we know whether or not the driver wants to have
703 * exclusive access to the port (PPEXCL).
706 file->private_data = pp;
711 static int pp_release (struct inode * inode, struct file * file)
713 unsigned int minor = iminor(inode);
714 struct pp_struct *pp = file->private_data;
718 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
719 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
720 struct ieee1284_info *info;
722 /* parport released, but not in compatibility mode */
723 parport_claim_or_block (pp->pdev);
724 pp->flags |= PP_CLAIMED;
725 info = &pp->pdev->port->ieee1284;
726 pp->saved_state.mode = info->mode;
727 pp->saved_state.phase = info->phase;
728 info->mode = pp->state.mode;
729 info->phase = pp->state.phase;
731 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
732 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
736 parport_negotiate (pp->pdev->port, IEEE1284_MODE_COMPAT);
737 pr_debug(CHRDEV "%x: negotiated back to compatibility "
738 "mode because user-space forgot\n", minor);
741 if (pp->flags & PP_CLAIMED) {
742 struct ieee1284_info *info;
744 info = &pp->pdev->port->ieee1284;
745 pp->state.mode = info->mode;
746 pp->state.phase = info->phase;
747 info->mode = pp->saved_state.mode;
748 info->phase = pp->saved_state.phase;
749 parport_release (pp->pdev);
750 if (compat_negot != 1) {
751 pr_debug(CHRDEV "%x: released pardevice "
752 "because user-space forgot\n", minor);
757 const char *name = pp->pdev->name;
758 parport_unregister_device (pp->pdev);
761 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
769 /* No kernel lock held - fine */
770 static unsigned int pp_poll (struct file * file, poll_table * wait)
772 struct pp_struct *pp = file->private_data;
773 unsigned int mask = 0;
775 poll_wait (file, &pp->irq_wait, wait);
776 if (atomic_read (&pp->irqc))
777 mask |= POLLIN | POLLRDNORM;
782 static struct class *ppdev_class;
784 static const struct file_operations pp_fops = {
785 .owner = THIS_MODULE,
790 .unlocked_ioctl = pp_ioctl,
792 .compat_ioctl = pp_compat_ioctl,
795 .release = pp_release,
798 static void pp_attach(struct parport *port)
800 device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
801 NULL, "parport%d", port->number);
804 static void pp_detach(struct parport *port)
806 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
809 static struct parport_driver pp_driver = {
815 static int __init ppdev_init (void)
819 if (register_chrdev (PP_MAJOR, CHRDEV, &pp_fops)) {
820 printk (KERN_WARNING CHRDEV ": unable to get major %d\n",
824 ppdev_class = class_create(THIS_MODULE, CHRDEV);
825 if (IS_ERR(ppdev_class)) {
826 err = PTR_ERR(ppdev_class);
829 err = parport_register_driver(&pp_driver);
831 printk (KERN_WARNING CHRDEV ": unable to register with parport\n");
835 printk (KERN_INFO PP_VERSION "\n");
839 class_destroy(ppdev_class);
841 unregister_chrdev(PP_MAJOR, CHRDEV);
846 static void __exit ppdev_cleanup (void)
848 /* Clean up all parport stuff */
849 parport_unregister_driver(&pp_driver);
850 class_destroy(ppdev_class);
851 unregister_chrdev (PP_MAJOR, CHRDEV);
854 module_init(ppdev_init);
855 module_exit(ppdev_cleanup);
857 MODULE_LICENSE("GPL");
858 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);