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;
90 /* should we use PARDEVICE_MAX here? */
91 static struct device *devices[PARPORT_MAX];
93 static DEFINE_IDA(ida_index);
95 /* pp_struct.flags bitfields */
96 #define PP_CLAIMED (1<<0)
97 #define PP_EXCL (1<<1)
100 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
101 #define PP_BUFFER_SIZE 1024
102 #define PARDEVICE_MAX 8
104 /* ROUND_UP macro from fs/select.c */
105 #define ROUND_UP(x,y) (((x)+(y)-1)/(y))
107 static DEFINE_MUTEX(pp_do_mutex);
109 /* define fixed sized ioctl cmd for y2038 migration */
110 #define PPGETTIME32 _IOR(PP_IOCTL, 0x95, s32[2])
111 #define PPSETTIME32 _IOW(PP_IOCTL, 0x96, s32[2])
112 #define PPGETTIME64 _IOR(PP_IOCTL, 0x95, s64[2])
113 #define PPSETTIME64 _IOW(PP_IOCTL, 0x96, s64[2])
115 static inline void pp_enable_irq(struct pp_struct *pp)
117 struct parport *port = pp->pdev->port;
119 port->ops->enable_irq(port);
122 static ssize_t pp_read(struct file *file, char __user *buf, size_t count,
125 unsigned int minor = iminor(file_inode(file));
126 struct pp_struct *pp = file->private_data;
128 ssize_t bytes_read = 0;
129 struct parport *pport;
132 if (!(pp->flags & PP_CLAIMED)) {
133 /* Don't have the port claimed */
134 pr_debug(CHRDEV "%x: claim the port first\n", minor);
142 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
145 pport = pp->pdev->port;
146 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
148 parport_set_timeout(pp->pdev,
149 (file->f_flags & O_NONBLOCK) ?
150 PARPORT_INACTIVITY_O_NONBLOCK :
151 pp->default_inactivity);
153 while (bytes_read == 0) {
154 ssize_t need = min_t(unsigned long, count, PP_BUFFER_SIZE);
156 if (mode == IEEE1284_MODE_EPP) {
157 /* various specials for EPP mode */
159 size_t (*fn)(struct parport *, void *, size_t, int);
161 if (pp->flags & PP_W91284PIC)
162 flags |= PARPORT_W91284PIC;
163 if (pp->flags & PP_FASTREAD)
164 flags |= PARPORT_EPP_FAST;
165 if (pport->ieee1284.mode & IEEE1284_ADDR)
166 fn = pport->ops->epp_read_addr;
168 fn = pport->ops->epp_read_data;
169 bytes_read = (*fn)(pport, kbuffer, need, flags);
171 bytes_read = parport_read(pport, kbuffer, need);
177 if (file->f_flags & O_NONBLOCK) {
178 bytes_read = -EAGAIN;
182 if (signal_pending(current)) {
183 bytes_read = -ERESTARTSYS;
190 parport_set_timeout(pp->pdev, pp->default_inactivity);
192 if (bytes_read > 0 && copy_to_user(buf, kbuffer, bytes_read))
193 bytes_read = -EFAULT;
200 static ssize_t pp_write(struct file *file, const char __user *buf,
201 size_t count, loff_t *ppos)
203 unsigned int minor = iminor(file_inode(file));
204 struct pp_struct *pp = file->private_data;
206 ssize_t bytes_written = 0;
209 struct parport *pport;
211 if (!(pp->flags & PP_CLAIMED)) {
212 /* Don't have the port claimed */
213 pr_debug(CHRDEV "%x: claim the port first\n", minor);
217 kbuffer = kmalloc(min_t(size_t, count, PP_BUFFER_SIZE), GFP_KERNEL);
221 pport = pp->pdev->port;
222 mode = pport->ieee1284.mode & ~(IEEE1284_DEVICEID | IEEE1284_ADDR);
224 parport_set_timeout(pp->pdev,
225 (file->f_flags & O_NONBLOCK) ?
226 PARPORT_INACTIVITY_O_NONBLOCK :
227 pp->default_inactivity);
229 while (bytes_written < count) {
230 ssize_t n = min_t(unsigned long, count - bytes_written, PP_BUFFER_SIZE);
232 if (copy_from_user(kbuffer, buf + bytes_written, n)) {
233 bytes_written = -EFAULT;
237 if ((pp->flags & PP_FASTWRITE) && (mode == IEEE1284_MODE_EPP)) {
238 /* do a fast EPP write */
239 if (pport->ieee1284.mode & IEEE1284_ADDR) {
240 wrote = pport->ops->epp_write_addr(pport,
241 kbuffer, n, PARPORT_EPP_FAST);
243 wrote = pport->ops->epp_write_data(pport,
244 kbuffer, n, PARPORT_EPP_FAST);
247 wrote = parport_write(pp->pdev->port, kbuffer, n);
252 bytes_written = wrote;
256 bytes_written += wrote;
258 if (file->f_flags & O_NONBLOCK) {
260 bytes_written = -EAGAIN;
264 if (signal_pending(current))
270 parport_set_timeout(pp->pdev, pp->default_inactivity);
274 return bytes_written;
277 static void pp_irq(void *private)
279 struct pp_struct *pp = private;
281 if (pp->irqresponse) {
282 parport_write_control(pp->pdev->port, pp->irqctl);
286 atomic_inc(&pp->irqc);
287 wake_up_interruptible(&pp->irq_wait);
290 static int register_device(int minor, struct pp_struct *pp)
292 struct parport *port;
293 struct pardevice *pdev = NULL;
295 struct pardev_cb ppdev_cb;
298 name = kasprintf(GFP_KERNEL, CHRDEV "%x", minor);
302 port = parport_find_number(minor);
304 printk(KERN_WARNING "%s: no associated port!\n", name);
309 index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL);
310 memset(&ppdev_cb, 0, sizeof(ppdev_cb));
311 ppdev_cb.irq_func = pp_irq;
312 ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0;
313 ppdev_cb.private = pp;
314 pdev = parport_register_dev_model(port, name, &ppdev_cb, index);
315 parport_put_port(port);
318 printk(KERN_WARNING "%s: failed to register device!\n", name);
319 ida_simple_remove(&ida_index, index);
326 dev_dbg(&pdev->dev, "registered pardevice\n");
330 static enum ieee1284_phase init_phase(int mode)
332 switch (mode & ~(IEEE1284_DEVICEID
334 case IEEE1284_MODE_NIBBLE:
335 case IEEE1284_MODE_BYTE:
336 return IEEE1284_PH_REV_IDLE;
338 return IEEE1284_PH_FWD_IDLE;
341 static int pp_set_timeout(struct pardevice *pdev, long tv_sec, int tv_usec)
345 if ((tv_sec < 0) || (tv_usec < 0))
348 to_jiffies = usecs_to_jiffies(tv_usec);
349 to_jiffies += tv_sec * HZ;
353 pdev->timeout = to_jiffies;
357 static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
359 unsigned int minor = iminor(file_inode(file));
360 struct pp_struct *pp = file->private_data;
361 struct parport *port;
362 void __user *argp = (void __user *)arg;
364 /* First handle the cases that don't take arguments. */
368 struct ieee1284_info *info;
371 if (pp->flags & PP_CLAIMED) {
372 dev_dbg(&pp->pdev->dev, "you've already got it!\n");
376 /* Deferred device registration. */
378 int err = register_device(minor, pp);
384 ret = parport_claim_or_block(pp->pdev);
388 pp->flags |= PP_CLAIMED;
390 /* For interrupt-reporting to work, we need to be
391 * informed of each interrupt. */
394 /* We may need to fix up the state machine. */
395 info = &pp->pdev->port->ieee1284;
396 pp->saved_state.mode = info->mode;
397 pp->saved_state.phase = info->phase;
398 info->mode = pp->state.mode;
399 info->phase = pp->state.phase;
400 pp->default_inactivity = parport_set_timeout(pp->pdev, 0);
401 parport_set_timeout(pp->pdev, pp->default_inactivity);
407 dev_dbg(&pp->pdev->dev,
408 "too late for PPEXCL; already registered\n");
409 if (pp->flags & PP_EXCL)
410 /* But it's not really an error. */
412 /* There's no chance of making the driver happy. */
416 /* Just remember to register the device exclusively
417 * when we finally do the registration. */
418 pp->flags |= PP_EXCL;
424 if (copy_from_user(&mode, argp, sizeof(mode)))
426 /* FIXME: validate mode */
427 pp->state.mode = mode;
428 pp->state.phase = init_phase(mode);
430 if (pp->flags & PP_CLAIMED) {
431 pp->pdev->port->ieee1284.mode = mode;
432 pp->pdev->port->ieee1284.phase = pp->state.phase;
441 if (pp->flags & PP_CLAIMED)
442 mode = pp->pdev->port->ieee1284.mode;
444 mode = pp->state.mode;
446 if (copy_to_user(argp, &mode, sizeof(mode)))
454 if (copy_from_user(&phase, argp, sizeof(phase)))
457 /* FIXME: validate phase */
458 pp->state.phase = phase;
460 if (pp->flags & PP_CLAIMED)
461 pp->pdev->port->ieee1284.phase = phase;
469 if (pp->flags & PP_CLAIMED)
470 phase = pp->pdev->port->ieee1284.phase;
472 phase = pp->state.phase;
473 if (copy_to_user(argp, &phase, sizeof(phase)))
481 port = parport_find_number(minor);
486 parport_put_port(port);
487 if (copy_to_user(argp, &modes, sizeof(modes)))
495 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)))
512 /* Everything else requires the port to be claimed, so check
514 if ((pp->flags & PP_CLAIMED) == 0) {
515 pr_debug(CHRDEV "%x: claim the port first\n", minor);
519 port = pp->pdev->port;
521 struct ieee1284_info *info;
527 struct timespec64 ts;
531 reg = parport_read_status(port);
532 if (copy_to_user(argp, ®, sizeof(reg)))
536 reg = parport_read_data(port);
537 if (copy_to_user(argp, ®, sizeof(reg)))
541 reg = parport_read_control(port);
542 if (copy_to_user(argp, ®, sizeof(reg)))
546 parport_yield_blocking(pp->pdev);
550 /* Save the state machine's state. */
551 info = &pp->pdev->port->ieee1284;
552 pp->state.mode = info->mode;
553 pp->state.phase = info->phase;
554 info->mode = pp->saved_state.mode;
555 info->phase = pp->saved_state.phase;
556 parport_release(pp->pdev);
557 pp->flags &= ~PP_CLAIMED;
561 if (copy_from_user(®, argp, sizeof(reg)))
563 parport_write_control(port, reg);
567 if (copy_from_user(®, argp, sizeof(reg)))
569 parport_write_data(port, reg);
573 if (copy_from_user(&mask, argp,
576 if (copy_from_user(®, 1 + (unsigned char __user *) arg,
579 parport_frob_control(port, mask, reg);
583 if (copy_from_user(&mode, argp, sizeof(mode)))
586 port->ops->data_reverse(port);
588 port->ops->data_forward(port);
592 if (copy_from_user(&mode, argp, sizeof(mode)))
594 switch ((ret = parport_negotiate(port, mode))) {
596 case -1: /* handshake failed, peripheral not IEEE 1284 */
599 case 1: /* handshake succeeded, peripheral rejected mode */
607 if (copy_from_user(®, argp, sizeof(reg)))
610 /* Remember what to set the control lines to, for next
611 * time we get an interrupt. */
617 ret = atomic_read(&pp->irqc);
618 if (copy_to_user(argp, &ret, sizeof(ret)))
620 atomic_sub(ret, &pp->irqc);
624 if (copy_from_user(time32, argp, sizeof(time32)))
627 if ((time32[0] < 0) || (time32[1] < 0))
630 return pp_set_timeout(pp->pdev, time32[0], time32[1]);
633 if (copy_from_user(time64, argp, sizeof(time64)))
636 if ((time64[0] < 0) || (time64[1] < 0))
639 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
642 return pp_set_timeout(pp->pdev, time64[0], time64[1]);
645 jiffies_to_timespec64(pp->pdev->timeout, &ts);
646 time32[0] = ts.tv_sec;
647 time32[1] = ts.tv_nsec / NSEC_PER_USEC;
649 if (copy_to_user(argp, time32, sizeof(time32)))
655 jiffies_to_timespec64(pp->pdev->timeout, &ts);
656 time64[0] = ts.tv_sec;
657 time64[1] = ts.tv_nsec / NSEC_PER_USEC;
659 if (IS_ENABLED(CONFIG_SPARC64) && !in_compat_syscall())
662 if (copy_to_user(argp, time64, sizeof(time64)))
668 dev_dbg(&pp->pdev->dev, "What? (cmd=0x%x)\n", cmd);
672 /* Keep the compiler happy */
676 static long pp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
680 mutex_lock(&pp_do_mutex);
681 ret = pp_do_ioctl(file, cmd, arg);
682 mutex_unlock(&pp_do_mutex);
687 static long pp_compat_ioctl(struct file *file, unsigned int cmd,
690 return pp_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
694 static int pp_open(struct inode *inode, struct file *file)
696 unsigned int minor = iminor(inode);
697 struct pp_struct *pp;
699 if (minor >= PARPORT_MAX)
702 pp = kmalloc(sizeof(struct pp_struct), GFP_KERNEL);
706 pp->state.mode = IEEE1284_MODE_COMPAT;
707 pp->state.phase = init_phase(pp->state.mode);
710 atomic_set(&pp->irqc, 0);
711 init_waitqueue_head(&pp->irq_wait);
713 /* Defer the actual device registration until the first claim.
714 * That way, we know whether or not the driver wants to have
715 * exclusive access to the port (PPEXCL).
718 file->private_data = pp;
723 static int pp_release(struct inode *inode, struct file *file)
725 unsigned int minor = iminor(inode);
726 struct pp_struct *pp = file->private_data;
730 if (!(pp->flags & PP_CLAIMED) && pp->pdev &&
731 (pp->state.mode != IEEE1284_MODE_COMPAT)) {
732 struct ieee1284_info *info;
734 /* parport released, but not in compatibility mode */
735 parport_claim_or_block(pp->pdev);
736 pp->flags |= PP_CLAIMED;
737 info = &pp->pdev->port->ieee1284;
738 pp->saved_state.mode = info->mode;
739 pp->saved_state.phase = info->phase;
740 info->mode = pp->state.mode;
741 info->phase = pp->state.phase;
743 } else if ((pp->flags & PP_CLAIMED) && pp->pdev &&
744 (pp->pdev->port->ieee1284.mode != IEEE1284_MODE_COMPAT)) {
748 parport_negotiate(pp->pdev->port, IEEE1284_MODE_COMPAT);
749 dev_dbg(&pp->pdev->dev,
750 "negotiated back to compatibility mode because user-space forgot\n");
753 if (pp->flags & PP_CLAIMED) {
754 struct ieee1284_info *info;
756 info = &pp->pdev->port->ieee1284;
757 pp->state.mode = info->mode;
758 pp->state.phase = info->phase;
759 info->mode = pp->saved_state.mode;
760 info->phase = pp->saved_state.phase;
761 parport_release(pp->pdev);
762 if (compat_negot != 1) {
763 pr_debug(CHRDEV "%x: released pardevice "
764 "because user-space forgot\n", minor);
769 parport_unregister_device(pp->pdev);
770 ida_simple_remove(&ida_index, pp->index);
772 pr_debug(CHRDEV "%x: unregistered pardevice\n", minor);
780 /* No kernel lock held - fine */
781 static unsigned int pp_poll(struct file *file, poll_table *wait)
783 struct pp_struct *pp = file->private_data;
784 unsigned int mask = 0;
786 poll_wait(file, &pp->irq_wait, wait);
787 if (atomic_read(&pp->irqc))
788 mask |= POLLIN | POLLRDNORM;
793 static struct class *ppdev_class;
795 static const struct file_operations pp_fops = {
796 .owner = THIS_MODULE,
801 .unlocked_ioctl = pp_ioctl,
803 .compat_ioctl = pp_compat_ioctl,
806 .release = pp_release,
809 static void pp_attach(struct parport *port)
813 if (devices[port->number])
816 ret = device_create(ppdev_class, port->dev,
817 MKDEV(PP_MAJOR, port->number), NULL,
818 "parport%d", port->number);
820 pr_err("Failed to create device parport%d\n",
824 devices[port->number] = ret;
827 static void pp_detach(struct parport *port)
829 if (!devices[port->number])
832 device_destroy(ppdev_class, MKDEV(PP_MAJOR, port->number));
833 devices[port->number] = NULL;
836 static int pp_probe(struct pardevice *par_dev)
838 struct device_driver *drv = par_dev->dev.driver;
839 int len = strlen(drv->name);
841 if (strncmp(par_dev->name, drv->name, len))
847 static struct parport_driver pp_driver = {
850 .match_port = pp_attach,
855 static int __init ppdev_init(void)
859 if (register_chrdev(PP_MAJOR, CHRDEV, &pp_fops)) {
860 printk(KERN_WARNING CHRDEV ": unable to get major %d\n",
864 ppdev_class = class_create(THIS_MODULE, CHRDEV);
865 if (IS_ERR(ppdev_class)) {
866 err = PTR_ERR(ppdev_class);
869 err = parport_register_driver(&pp_driver);
871 printk(KERN_WARNING CHRDEV ": unable to register with parport\n");
875 printk(KERN_INFO PP_VERSION "\n");
879 class_destroy(ppdev_class);
881 unregister_chrdev(PP_MAJOR, CHRDEV);
886 static void __exit ppdev_cleanup(void)
888 /* Clean up all parport stuff */
889 parport_unregister_driver(&pp_driver);
890 class_destroy(ppdev_class);
891 unregister_chrdev(PP_MAJOR, CHRDEV);
894 module_init(ppdev_init);
895 module_exit(ppdev_cleanup);
897 MODULE_LICENSE("GPL");
898 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR);