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;
113 port->ops->enable_irq(port);
116 static ssize_t pp_read(struct file *file, char __user *buf, size_t count,
119 unsigned int minor = iminor(file_inode(file));
120 struct pp_struct *pp = file->private_data;
122 ssize_t bytes_read = 0;
123 struct parport *pport;
126 if (!(pp->flags & PP_CLAIMED)) {
127 /* Don't have the port claimed */
128 pr_debug(CHRDEV "%x: claim the port first\n", minor);
136 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
140 pport = pp->pdev->port;
141 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
143 parport_set_timeout(pp->pdev,
144 (file->f_flags & O_NONBLOCK) ?
145 PARPORT_INACTIVITY_O_NONBLOCK :
146 pp->default_inactivity);
148 while (bytes_read == 0) {
149 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
151 if (mode == IEEE1284_MODE_EPP) {
152 /* various specials for EPP mode */
154 size_t (*fn)(struct parport *, void *, size_t, int);
156 if (pp->flags & PP_W91284PIC) {
157 flags |= PARPORT_W91284PIC;
159 if (pp->flags & PP_FASTREAD) {
160 flags |= PARPORT_EPP_FAST;
162 if (pport->ieee1284.mode & IEEE1284_ADDR) {
163 fn = pport->ops->epp_read_addr;
165 fn = pport->ops->epp_read_data;
167 bytes_read = (*fn)(pport, kbuffer, need, flags);
169 bytes_read = parport_read(pport, kbuffer, need);
175 if (file->f_flags & O_NONBLOCK) {
176 bytes_read = -EAGAIN;
180 if (signal_pending(current)) {
181 bytes_read = -ERESTARTSYS;
188 parport_set_timeout(pp->pdev, pp->default_inactivity);
190 if (bytes_read > 0 && copy_to_user(buf, kbuffer, bytes_read))
191 bytes_read = -EFAULT;
198 static ssize_t pp_write(struct file *file, const char __user *buf,
199 size_t count, loff_t *ppos)
201 unsigned int minor = iminor(file_inode(file));
202 struct pp_struct *pp = file->private_data;
204 ssize_t bytes_written = 0;
207 struct parport *pport;
209 if (!(pp->flags & PP_CLAIMED)) {
210 /* Don't have the port claimed */
211 pr_debug(CHRDEV "%x: claim the port first\n", minor);
215 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
219 pport = pp->pdev->port;
220 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
222 parport_set_timeout(pp->pdev,
223 (file->f_flags & O_NONBLOCK) ?
224 PARPORT_INACTIVITY_O_NONBLOCK :
225 pp->default_inactivity);
227 while (bytes_written < count) {
228 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
230 if (copy_from_user(kbuffer, buf + bytes_written, n)) {
231 bytes_written = -EFAULT;
235 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
236 /* do a fast EPP write */
237 if (pport->ieee1284.mode & IEEE1284_ADDR) {
238 wrote = pport->ops->epp_write_addr(pport,
239 kbuffer, n, PARPORT_EPP_FAST);
241 wrote = pport->ops->epp_write_data(pport,
242 kbuffer, n, PARPORT_EPP_FAST);
245 wrote = parport_write(pp->pdev->port, kbuffer, n);
249 if (!bytes_written) {
250 bytes_written = wrote;
255 bytes_written += wrote;
257 if (file->f_flags & O_NONBLOCK) {
259 bytes_written = -EAGAIN;
263 if (signal_pending(current))
269 parport_set_timeout(pp->pdev, pp->default_inactivity);
273 return bytes_written;
276 static void pp_irq(void *private)
278 struct pp_struct *pp = private;
280 if (pp->irqresponse) {
281 parport_write_control(pp->pdev->port, pp->irqctl);
285 atomic_inc(&pp->irqc);
286 wake_up_interruptible(&pp->irq_wait);
289 static int register_device(int minor, struct pp_struct *pp)
291 struct parport *port;
292 struct pardevice *pdev = NULL;
296 name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
300 port = parport_find_number(minor);
302 printk(KERN_WARNING "%s: no associated port!\n", name);
307 fl = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
308 pdev = parport_register_device(port, name, NULL,
309 NULL, pp_irq, fl, pp);
310 parport_put_port(port);
313 printk(KERN_WARNING "%s: failed to register device!\n", name);
319 pr_debug("%s: registered pardevice\n", name);
323 static enum ieee1284_phase init_phase(int mode)
325 switch (mode & ~(IEEE1284_DEVICEID
327 case IEEE1284_MODE_NIBBLE:
328 case IEEE1284_MODE_BYTE:
329 return IEEE1284_PH_REV_IDLE;
331 return IEEE1284_PH_FWD_IDLE;
334 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
338 if ((tv_sec < 0) || (tv_usec < 0))
341 to_jiffies = usecs_to_jiffies(tv_usec);
342 to_jiffies += tv_sec * HZ;
346 pdev->timeout = to_jiffies;
350 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
352 unsigned int minor = iminor(file_inode(file));
353 struct pp_struct *pp = file->private_data;
354 struct parport *port;
355 void __user *argp = (void __user *)arg;
357 /* First handle the cases that don't take arguments. */
361 struct ieee1284_info *info;
364 if (pp->flags & PP_CLAIMED) {
365 pr_debug(CHRDEV "%x: you've already got it!\n", minor);
369 /* Deferred device registration. */
371 int err = register_device(minor, pp);
378 ret = parport_claim_or_block(pp->pdev);
382 pp->flags |= PP_CLAIMED;
384 /* For interrupt-reporting to work, we need to be
385 * informed of each interrupt. */
388 /* We may need to fix up the state machine. */
389 info = &pp->pdev->port->ieee1284;
390 pp->saved_state.mode = info->mode;
391 pp->saved_state.phase = info->phase;
392 info->mode = pp->state.mode;
393 info->phase = pp->state.phase;
394 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
395 parport_set_timeout(pp->pdev, pp->default_inactivity);
401 pr_debug(CHRDEV "%x: too late for PPEXCL; "
402 "already registered\n", minor);
403 if (pp->flags & PP_EXCL)
404 /* But it's not really an error. */
406 /* There's no chance of making the driver happy. */
410 /* Just remember to register the device exclusively
411 * when we finally do the registration. */
412 pp->flags |= PP_EXCL;
418 if (copy_from_user(&mode, argp, sizeof(mode)))
420 /* FIXME: validate mode */
421 pp->state.mode = mode;
422 pp->state.phase = init_phase(mode);
424 if (pp->flags & PP_CLAIMED) {
425 pp->pdev->port->ieee1284.mode = mode;
426 pp->pdev->port->ieee1284.phase = pp->state.phase;
435 if (pp->flags & PP_CLAIMED) {
436 mode = pp->pdev->port->ieee1284.mode;
438 mode = pp->state.mode;
440 if (copy_to_user(argp, &mode, sizeof(mode))) {
449 if (copy_from_user(&phase, argp, sizeof(phase))) {
452 /* FIXME: validate phase */
453 pp->state.phase = phase;
455 if (pp->flags & PP_CLAIMED) {
456 pp->pdev->port->ieee1284.phase = phase;
465 if (pp->flags & PP_CLAIMED) {
466 phase = pp->pdev->port->ieee1284.phase;
468 phase = pp->state.phase;
470 if (copy_to_user(argp, &phase, sizeof(phase))) {
479 port = parport_find_number(minor);
484 parport_put_port(port);
485 if (copy_to_user(argp, &modes, sizeof(modes))) {
494 if (copy_from_user(&uflags, argp, sizeof(uflags))) {
497 pp->flags &= ~PP_FLAGMASK;
498 pp->flags |= (uflags & PP_FLAGMASK);
505 uflags = pp->flags & PP_FLAGMASK;
506 if (copy_to_user(argp, &uflags, sizeof(uflags))) {
513 /* Everything else requires the port to be claimed, so check
515 if ((pp->flags & PP_CLAIMED) == 0) {
516 pr_debug(CHRDEV "%x: claim the port first\n", minor);
520 port = pp->pdev->port;
522 struct ieee1284_info *info;
528 struct timespec64 ts;
532 reg = parport_read_status(port);
533 if (copy_to_user(argp, ®, sizeof(reg)))
537 reg = parport_read_data(port);
538 if (copy_to_user(argp, ®, sizeof(reg)))
542 reg = parport_read_control(port);
543 if (copy_to_user(argp, ®, sizeof(reg)))
547 parport_yield_blocking(pp->pdev);
551 /* Save the state machine's state. */
552 info = &pp->pdev->port->ieee1284;
553 pp->state.mode = info->mode;
554 pp->state.phase = info->phase;
555 info->mode = pp->saved_state.mode;
556 info->phase = pp->saved_state.phase;
557 parport_release(pp->pdev);
558 pp->flags &= ~PP_CLAIMED;
562 if (copy_from_user(®, argp, sizeof(reg)))
564 parport_write_control(port, reg);
568 if (copy_from_user(®, argp, sizeof(reg)))
570 parport_write_data(port, reg);
574 if (copy_from_user(&mask, argp,
577 if (copy_from_user(®, 1 + (unsigned char __user *) arg,
580 parport_frob_control(port, mask, reg);
584 if (copy_from_user(&mode, argp, sizeof(mode)))
587 port->ops->data_reverse(port);
589 port->ops->data_forward(port);
593 if (copy_from_user(&mode, argp, sizeof(mode)))
595 switch ((ret = parport_negotiate(port, mode))) {
597 case -1: /* handshake failed, peripheral not IEEE 1284 */
600 case 1: /* handshake succeeded, peripheral rejected mode */
608 if (copy_from_user(®, argp, sizeof(reg)))
611 /* Remember what to set the control lines to, for next
612 * time we get an interrupt. */
618 ret = atomic_read(&pp->irqc);
619 if (copy_to_user(argp, &ret, sizeof(ret)))
621 atomic_sub(ret, &pp->irqc);
625 if (copy_from_user(time32, argp, sizeof(time32)))
628 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
631 if (copy_from_user(time64, argp, sizeof(time64)))
634 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
637 jiffies_to_timespec64(pp->pdev->timeout, &ts);
638 time32[0] = ts.tv_sec;
639 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
640 if ((time32[0] < 0) || (time32[1] < 0))
643 if (copy_to_user(argp, time32, sizeof(time32)))
649 jiffies_to_timespec64(pp->pdev->timeout, &ts);
650 time64[0] = ts.tv_sec;
651 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
652 if ((time64[0] < 0) || (time64[1] < 0))
655 if (copy_to_user(argp, time64, sizeof(time64)))
661 pr_debug(CHRDEV "%x: What? (cmd=0x%x)\n", minor, cmd);
665 /* Keep the compiler happy */
669 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
673 mutex_lock(&pp_do_mutex);
674 ret = pp_do_ioctl(file, cmd, arg);
675 mutex_unlock(&pp_do_mutex);
680 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
683 return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
687 static int pp_open(struct inode *inode, struct file *file)
689 unsigned int minor = iminor(inode);
690 struct pp_struct *pp;
692 if (minor >= PARPORT_MAX)
695 pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
699 pp->state.mode = IEEE1284_MODE_COMPAT;
700 pp->state.phase = init_phase(pp->state.mode);
703 atomic_set(&pp->irqc, 0);
704 init_waitqueue_head(&pp->irq_wait);
706 /* Defer the actual device registration until the first claim.
707 * That way, we know whether or not the driver wants to have
708 * exclusive access to the port (PPEXCL).
711 file->private_data = pp;
716 static int pp_release(struct inode *inode, struct file *file)
718 unsigned int minor = iminor(inode);
719 struct pp_struct *pp = file->private_data;
723 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
724 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
725 struct ieee1284_info *info;
727 /* parport released, but not in compatibility mode */
728 parport_claim_or_block(pp->pdev);
729 pp->flags |= PP_CLAIMED;
730 info = &pp->pdev->port->ieee1284;
731 pp->saved_state.mode = info->mode;
732 pp->saved_state.phase = info->phase;
733 info->mode = pp->state.mode;
734 info->phase = pp->state.phase;
736 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
737 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
741 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
742 pr_debug(CHRDEV "%x: negotiated back to compatibility "
743 "mode because user-space forgot\n", minor);
746 if (pp->flags & PP_CLAIMED) {
747 struct ieee1284_info *info;
749 info = &pp->pdev->port->ieee1284;
750 pp->state.mode = info->mode;
751 pp->state.phase = info->phase;
752 info->mode = pp->saved_state.mode;
753 info->phase = pp->saved_state.phase;
754 parport_release(pp->pdev);
755 if (compat_negot != 1) {
756 pr_debug(CHRDEV "%x: released pardevice "
757 "because user-space forgot\n", minor);
762 const char *name = pp->pdev->name;
764 parport_unregister_device(pp->pdev);
767 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
775 /* No kernel lock held - fine */
776 static unsigned int pp_poll(struct file *file, poll_table *wait)
778 struct pp_struct *pp = file->private_data;
779 unsigned int mask = 0;
781 poll_wait(file, &pp->irq_wait, wait);
782 if (atomic_read(&pp->irqc))
783 mask |= POLLIN | POLLRDNORM;
788 static struct class *ppdev_class;
790 static const struct file_operations pp_fops = {
791 .owner = THIS_MODULE,
796 .unlocked_ioctl = pp_ioctl,
798 .compat_ioctl = pp_compat_ioctl,
801 .release = pp_release,
804 static void pp_attach(struct parport *port)
806 device_create(ppdev_class, port->dev, MKDEV(PP_MAJOR, port->number),
807 NULL, "parport%d", port->number);
810 static void pp_detach(struct parport *port)
812 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
815 static struct parport_driver pp_driver = {
821 static int __init ppdev_init(void)
825 if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
826 printk(KERN_WARNING CHRDEV ": unable to get major %d\n",
830 ppdev_class = class_create(THIS_MODULE, CHRDEV);
831 if (IS_ERR(ppdev_class)) {
832 err = PTR_ERR(ppdev_class);
835 err = parport_register_driver(&pp_driver);
837 printk(KERN_WARNING CHRDEV ": unable to register with parport\n");
841 printk(KERN_INFO PP_VERSION "\n");
845 class_destroy(ppdev_class);
847 unregister_chrdev(PP_MAJOR, CHRDEV);
852 static void __exit ppdev_cleanup(void)
854 /* Clean up all parport stuff */
855 parport_unregister_driver(&pp_driver);
856 class_destroy(ppdev_class);
857 unregister_chrdev(PP_MAJOR, CHRDEV);
860 module_init(ppdev_init);
861 module_exit(ppdev_cleanup);
863 MODULE_LICENSE("GPL");
864 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);