1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * linux/drivers/char/ppdev.c
5 * This is the code behind /dev/parport* -- it allows a user-space
6 * application to use the parport subsystem.
8 * Copyright (C) 1998-2000, 2002 Tim Waugh <tim@cyberelk.net>
10 * A /dev/parportx device node represents an arbitrary device
11 * on port 'x'. The following operations are possible:
13 * open do nothing, set up default IEEE 1284 protocol to be COMPAT
14 * close release port and unregister device (if necessary)
16 * EXCL register device exclusively (may fail)
17 * CLAIM (register device first time) parport_claim_or_block
18 * RELEASE parport_release
19 * SETMODE set the IEEE 1284 protocol to use for read/write
20 * SETPHASE set the IEEE 1284 phase of a particular mode. Not to be
21 * confused with ioctl(fd, SETPHASER, &stun). ;-)
22 * DATADIR data_forward / data_reverse
25 * WCONTROL write_control
26 * RCONTROL read_control
27 * FCONTROL frob_control
29 * NEGOT parport_negotiate
30 * YIELD parport_yield_blocking
31 * WCTLONIRQ on interrupt, set control lines
32 * CLRIRQ clear (and return) interrupt count
33 * SETTIME sets device timeout (struct timeval)
34 * GETTIME gets device timeout (struct timeval)
35 * GETMODES gets hardware supported modes (unsigned int)
36 * GETMODE gets the current IEEE1284 mode
37 * GETPHASE gets the current IEEE1284 phase
38 * GETFLAGS gets current (user-visible) flags
39 * SETFLAGS sets current (user-visible) flags
40 * read/write read or write in current IEEE 1284 protocol
41 * select wait for interrupt (in readfds)
44 * Added SETTIME/GETTIME ioctl, Fred Barnes, 1999.
46 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25
47 * - On error, copy_from_user and copy_to_user do not return -EFAULT,
48 * They return the positive number of bytes *not* copied due to address
51 * Added GETMODES/GETMODE/GETPHASE ioctls, Fred Barnes <frmb2@ukc.ac.uk>, 03/01/2001.
52 * Added GETFLAGS/SETFLAGS ioctls, Fred Barnes, 04/2001
55 #include <linux/module.h>
56 #include <linux/init.h>
57 #include <linux/sched/signal.h>
58 #include <linux/device.h>
59 #include <linux/ioctl.h>
60 #include <linux/parport.h>
61 #include <linux/ctype.h>
62 #include <linux/poll.h>
63 #include <linux/slab.h>
64 #include <linux/major.h>
65 #include <linux/ppdev.h>
66 #include <linux/mutex.h>
67 #include <linux/uaccess.h>
68 #include <linux/compat.h>
70 #define PP_VERSION "ppdev: user-space parallel port driver"
71 #define CHRDEV "ppdev"
74 struct pardevice
*pdev
;
75 wait_queue_head_t irq_wait
;
80 struct ieee1284_info state
;
81 struct ieee1284_info saved_state
;
82 long default_inactivity
;
86 /* should we use PARDEVICE_MAX here? */
87 static struct device
*devices
[PARPORT_MAX
];
89 static DEFINE_IDA(ida_index
);
91 /* pp_struct.flags bitfields */
92 #define PP_CLAIMED (1<<0)
93 #define PP_EXCL (1<<1)
96 #define PP_INTERRUPT_TIMEOUT (10 * HZ) /* 10s */
97 #define PP_BUFFER_SIZE 1024
98 #define PARDEVICE_MAX 8
100 static DEFINE_MUTEX(pp_do_mutex
);
102 /* define fixed sized ioctl cmd for y2038 migration */
103 #define PPGETTIME32 _IOR(PP_IOCTL, 0x95, s32[2])
104 #define PPSETTIME32 _IOW(PP_IOCTL, 0x96, s32[2])
105 #define PPGETTIME64 _IOR(PP_IOCTL, 0x95, s64[2])
106 #define PPSETTIME64 _IOW(PP_IOCTL, 0x96, s64[2])
108 static inline void pp_enable_irq(struct pp_struct
*pp
)
110 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
);
138 pport
= pp
->pdev
->port
;
139 mode
= pport
->ieee1284
.mode
& ~(IEEE1284_DEVICEID
| IEEE1284_ADDR
);
141 parport_set_timeout(pp
->pdev
,
142 (file
->f_flags
& O_NONBLOCK
) ?
143 PARPORT_INACTIVITY_O_NONBLOCK
:
144 pp
->default_inactivity
);
146 while (bytes_read
== 0) {
147 ssize_t need
= min_t(unsigned long, count
, PP_BUFFER_SIZE
);
149 if (mode
== IEEE1284_MODE_EPP
) {
150 /* various specials for EPP mode */
152 size_t (*fn
)(struct parport
*, void *, size_t, int);
154 if (pp
->flags
& PP_W91284PIC
)
155 flags
|= PARPORT_W91284PIC
;
156 if (pp
->flags
& PP_FASTREAD
)
157 flags
|= PARPORT_EPP_FAST
;
158 if (pport
->ieee1284
.mode
& IEEE1284_ADDR
)
159 fn
= pport
->ops
->epp_read_addr
;
161 fn
= pport
->ops
->epp_read_data
;
162 bytes_read
= (*fn
)(pport
, kbuffer
, need
, flags
);
164 bytes_read
= parport_read(pport
, kbuffer
, need
);
170 if (file
->f_flags
& O_NONBLOCK
) {
171 bytes_read
= -EAGAIN
;
175 if (signal_pending(current
)) {
176 bytes_read
= -ERESTARTSYS
;
183 parport_set_timeout(pp
->pdev
, pp
->default_inactivity
);
185 if (bytes_read
> 0 && copy_to_user(buf
, kbuffer
, bytes_read
))
186 bytes_read
= -EFAULT
;
193 static ssize_t
pp_write(struct file
*file
, const char __user
*buf
,
194 size_t count
, loff_t
*ppos
)
196 unsigned int minor
= iminor(file_inode(file
));
197 struct pp_struct
*pp
= file
->private_data
;
199 ssize_t bytes_written
= 0;
202 struct parport
*pport
;
204 if (!(pp
->flags
& PP_CLAIMED
)) {
205 /* Don't have the port claimed */
206 pr_debug(CHRDEV
"%x: claim the port first\n", minor
);
210 kbuffer
= kmalloc(min_t(size_t, count
, PP_BUFFER_SIZE
), GFP_KERNEL
);
214 pport
= pp
->pdev
->port
;
215 mode
= pport
->ieee1284
.mode
& ~(IEEE1284_DEVICEID
| IEEE1284_ADDR
);
217 parport_set_timeout(pp
->pdev
,
218 (file
->f_flags
& O_NONBLOCK
) ?
219 PARPORT_INACTIVITY_O_NONBLOCK
:
220 pp
->default_inactivity
);
222 while (bytes_written
< count
) {
223 ssize_t n
= min_t(unsigned long, count
- bytes_written
, PP_BUFFER_SIZE
);
225 if (copy_from_user(kbuffer
, buf
+ bytes_written
, n
)) {
226 bytes_written
= -EFAULT
;
230 if ((pp
->flags
& PP_FASTWRITE
) && (mode
== IEEE1284_MODE_EPP
)) {
231 /* do a fast EPP write */
232 if (pport
->ieee1284
.mode
& IEEE1284_ADDR
) {
233 wrote
= pport
->ops
->epp_write_addr(pport
,
234 kbuffer
, n
, PARPORT_EPP_FAST
);
236 wrote
= pport
->ops
->epp_write_data(pport
,
237 kbuffer
, n
, PARPORT_EPP_FAST
);
240 wrote
= parport_write(pp
->pdev
->port
, kbuffer
, n
);
245 bytes_written
= wrote
;
249 bytes_written
+= wrote
;
251 if (file
->f_flags
& O_NONBLOCK
) {
253 bytes_written
= -EAGAIN
;
257 if (signal_pending(current
))
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
;
288 struct pardev_cb ppdev_cb
;
291 name
= kasprintf(GFP_KERNEL
, CHRDEV
"%x", minor
);
295 port
= parport_find_number(minor
);
297 pr_warn("%s: no associated port!\n", name
);
302 index
= ida_simple_get(&ida_index
, 0, 0, GFP_KERNEL
);
303 memset(&ppdev_cb
, 0, sizeof(ppdev_cb
));
304 ppdev_cb
.irq_func
= pp_irq
;
305 ppdev_cb
.flags
= (pp
->flags
& PP_EXCL
) ? PARPORT_FLAG_EXCL
: 0;
306 ppdev_cb
.private = pp
;
307 pdev
= parport_register_dev_model(port
, name
, &ppdev_cb
, index
);
308 parport_put_port(port
);
311 pr_warn("%s: failed to register device!\n", name
);
313 ida_simple_remove(&ida_index
, index
);
319 dev_dbg(&pdev
->dev
, "registered pardevice\n");
325 static enum ieee1284_phase
init_phase(int mode
)
327 switch (mode
& ~(IEEE1284_DEVICEID
329 case IEEE1284_MODE_NIBBLE
:
330 case IEEE1284_MODE_BYTE
:
331 return IEEE1284_PH_REV_IDLE
;
333 return IEEE1284_PH_FWD_IDLE
;
336 static int pp_set_timeout(struct pardevice
*pdev
, long tv_sec
, int tv_usec
)
340 if ((tv_sec
< 0) || (tv_usec
< 0))
343 to_jiffies
= usecs_to_jiffies(tv_usec
);
344 to_jiffies
+= tv_sec
* HZ
;
348 pdev
->timeout
= to_jiffies
;
352 static int pp_do_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
354 unsigned int minor
= iminor(file_inode(file
));
355 struct pp_struct
*pp
= file
->private_data
;
356 struct parport
*port
;
357 void __user
*argp
= (void __user
*)arg
;
358 struct ieee1284_info
*info
;
364 struct timespec64 ts
;
367 /* First handle the cases that don't take arguments. */
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
;
522 reg
= parport_read_status(port
);
523 if (copy_to_user(argp
, ®
, sizeof(reg
)))
527 reg
= parport_read_data(port
);
528 if (copy_to_user(argp
, ®
, sizeof(reg
)))
532 reg
= parport_read_control(port
);
533 if (copy_to_user(argp
, ®
, sizeof(reg
)))
537 parport_yield_blocking(pp
->pdev
);
541 /* Save the state machine's state. */
542 info
= &pp
->pdev
->port
->ieee1284
;
543 pp
->state
.mode
= info
->mode
;
544 pp
->state
.phase
= info
->phase
;
545 info
->mode
= pp
->saved_state
.mode
;
546 info
->phase
= pp
->saved_state
.phase
;
547 parport_release(pp
->pdev
);
548 pp
->flags
&= ~PP_CLAIMED
;
552 if (copy_from_user(®
, argp
, sizeof(reg
)))
554 parport_write_control(port
, reg
);
558 if (copy_from_user(®
, argp
, sizeof(reg
)))
560 parport_write_data(port
, reg
);
564 if (copy_from_user(&mask
, argp
,
567 if (copy_from_user(®
, 1 + (unsigned char __user
*) arg
,
570 parport_frob_control(port
, mask
, reg
);
574 if (copy_from_user(&mode
, argp
, sizeof(mode
)))
577 port
->ops
->data_reverse(port
);
579 port
->ops
->data_forward(port
);
583 if (copy_from_user(&mode
, argp
, sizeof(mode
)))
585 switch ((ret
= parport_negotiate(port
, mode
))) {
587 case -1: /* handshake failed, peripheral not IEEE 1284 */
590 case 1: /* handshake succeeded, peripheral rejected mode */
598 if (copy_from_user(®
, argp
, sizeof(reg
)))
601 /* Remember what to set the control lines to, for next
602 * time we get an interrupt. */
608 ret
= atomic_read(&pp
->irqc
);
609 if (copy_to_user(argp
, &ret
, sizeof(ret
)))
611 atomic_sub(ret
, &pp
->irqc
);
615 if (copy_from_user(time32
, argp
, sizeof(time32
)))
618 if ((time32
[0] < 0) || (time32
[1] < 0))
621 return pp_set_timeout(pp
->pdev
, time32
[0], time32
[1]);
624 if (copy_from_user(time64
, argp
, sizeof(time64
)))
627 if ((time64
[0] < 0) || (time64
[1] < 0))
630 if (IS_ENABLED(CONFIG_SPARC64
) && !in_compat_syscall())
633 return pp_set_timeout(pp
->pdev
, time64
[0], time64
[1]);
636 jiffies_to_timespec64(pp
->pdev
->timeout
, &ts
);
637 time32
[0] = ts
.tv_sec
;
638 time32
[1] = ts
.tv_nsec
/ NSEC_PER_USEC
;
640 if (copy_to_user(argp
, time32
, sizeof(time32
)))
646 jiffies_to_timespec64(pp
->pdev
->timeout
, &ts
);
647 time64
[0] = ts
.tv_sec
;
648 time64
[1] = ts
.tv_nsec
/ NSEC_PER_USEC
;
650 if (IS_ENABLED(CONFIG_SPARC64
) && !in_compat_syscall())
653 if (copy_to_user(argp
, time64
, sizeof(time64
)))
659 dev_dbg(&pp
->pdev
->dev
, "What? (cmd=0x%x)\n", cmd
);
663 /* Keep the compiler happy */
667 static long pp_ioctl(struct file
*file
, unsigned int cmd
, unsigned long arg
)
671 mutex_lock(&pp_do_mutex
);
672 ret
= pp_do_ioctl(file
, cmd
, arg
);
673 mutex_unlock(&pp_do_mutex
);
677 static int pp_open(struct inode
*inode
, struct file
*file
)
679 unsigned int minor
= iminor(inode
);
680 struct pp_struct
*pp
;
682 if (minor
>= PARPORT_MAX
)
685 pp
= kmalloc(sizeof(struct pp_struct
), GFP_KERNEL
);
689 pp
->state
.mode
= IEEE1284_MODE_COMPAT
;
690 pp
->state
.phase
= init_phase(pp
->state
.mode
);
693 atomic_set(&pp
->irqc
, 0);
694 init_waitqueue_head(&pp
->irq_wait
);
696 /* Defer the actual device registration until the first claim.
697 * That way, we know whether or not the driver wants to have
698 * exclusive access to the port (PPEXCL).
701 file
->private_data
= pp
;
706 static int pp_release(struct inode
*inode
, struct file
*file
)
708 unsigned int minor
= iminor(inode
);
709 struct pp_struct
*pp
= file
->private_data
;
713 if (!(pp
->flags
& PP_CLAIMED
) && pp
->pdev
&&
714 (pp
->state
.mode
!= IEEE1284_MODE_COMPAT
)) {
715 struct ieee1284_info
*info
;
717 /* parport released, but not in compatibility mode */
718 parport_claim_or_block(pp
->pdev
);
719 pp
->flags
|= PP_CLAIMED
;
720 info
= &pp
->pdev
->port
->ieee1284
;
721 pp
->saved_state
.mode
= info
->mode
;
722 pp
->saved_state
.phase
= info
->phase
;
723 info
->mode
= pp
->state
.mode
;
724 info
->phase
= pp
->state
.phase
;
726 } else if ((pp
->flags
& PP_CLAIMED
) && pp
->pdev
&&
727 (pp
->pdev
->port
->ieee1284
.mode
!= IEEE1284_MODE_COMPAT
)) {
731 parport_negotiate(pp
->pdev
->port
, IEEE1284_MODE_COMPAT
);
732 dev_dbg(&pp
->pdev
->dev
,
733 "negotiated back to compatibility mode because user-space forgot\n");
736 if ((pp
->flags
& PP_CLAIMED
) && pp
->pdev
) {
737 struct ieee1284_info
*info
;
739 info
= &pp
->pdev
->port
->ieee1284
;
740 pp
->state
.mode
= info
->mode
;
741 pp
->state
.phase
= info
->phase
;
742 info
->mode
= pp
->saved_state
.mode
;
743 info
->phase
= pp
->saved_state
.phase
;
744 parport_release(pp
->pdev
);
745 if (compat_negot
!= 1) {
746 pr_debug(CHRDEV
"%x: released pardevice "
747 "because user-space forgot\n", minor
);
752 parport_unregister_device(pp
->pdev
);
753 ida_simple_remove(&ida_index
, pp
->index
);
755 pr_debug(CHRDEV
"%x: unregistered pardevice\n", minor
);
763 /* No kernel lock held - fine */
764 static __poll_t
pp_poll(struct file
*file
, poll_table
*wait
)
766 struct pp_struct
*pp
= file
->private_data
;
769 poll_wait(file
, &pp
->irq_wait
, wait
);
770 if (atomic_read(&pp
->irqc
))
771 mask
|= EPOLLIN
| EPOLLRDNORM
;
776 static struct class *ppdev_class
;
778 static const struct file_operations pp_fops
= {
779 .owner
= THIS_MODULE
,
784 .unlocked_ioctl
= pp_ioctl
,
785 .compat_ioctl
= compat_ptr_ioctl
,
787 .release
= pp_release
,
790 static void pp_attach(struct parport
*port
)
794 if (devices
[port
->number
])
797 ret
= device_create(ppdev_class
, port
->dev
,
798 MKDEV(PP_MAJOR
, port
->number
), NULL
,
799 "parport%d", port
->number
);
801 pr_err("Failed to create device parport%d\n",
805 devices
[port
->number
] = ret
;
808 static void pp_detach(struct parport
*port
)
810 if (!devices
[port
->number
])
813 device_destroy(ppdev_class
, MKDEV(PP_MAJOR
, port
->number
));
814 devices
[port
->number
] = NULL
;
817 static int pp_probe(struct pardevice
*par_dev
)
819 struct device_driver
*drv
= par_dev
->dev
.driver
;
820 int len
= strlen(drv
->name
);
822 if (strncmp(par_dev
->name
, drv
->name
, len
))
828 static struct parport_driver pp_driver
= {
831 .match_port
= pp_attach
,
836 static int __init
ppdev_init(void)
840 if (register_chrdev(PP_MAJOR
, CHRDEV
, &pp_fops
)) {
841 pr_warn(CHRDEV
": unable to get major %d\n", PP_MAJOR
);
844 ppdev_class
= class_create(THIS_MODULE
, CHRDEV
);
845 if (IS_ERR(ppdev_class
)) {
846 err
= PTR_ERR(ppdev_class
);
849 err
= parport_register_driver(&pp_driver
);
851 pr_warn(CHRDEV
": unable to register with parport\n");
855 pr_info(PP_VERSION
"\n");
859 class_destroy(ppdev_class
);
861 unregister_chrdev(PP_MAJOR
, CHRDEV
);
866 static void __exit
ppdev_cleanup(void)
868 /* Clean up all parport stuff */
869 parport_unregister_driver(&pp_driver
);
870 class_destroy(ppdev_class
);
871 unregister_chrdev(PP_MAJOR
, CHRDEV
);
874 module_init(ppdev_init
);
875 module_exit(ppdev_cleanup
);
877 MODULE_LICENSE("GPL");
878 MODULE_ALIAS_CHARDEV_MAJOR(PP_MAJOR
);