2 comedi/drivers/comedi_parport.c
3 hardware driver for standard parallel port
5 COMEDI - Linux Control and Measurement Device Interface
6 Copyright (C) 1998,2001 David A. Schleef <ds@schleef.org>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 Driver: comedi_parport
25 Description: Standard PC parallel port
27 Status: works in immediate mode
28 Devices: [standard] parallel port (comedi_parport)
29 Updated: Tue, 30 Apr 2002 21:11:45 -0700
31 A cheap and easy way to get a few more digital I/O lines. Steal
32 additional parallel ports from old computers or your neighbors'
36 0: I/O port base for the parallel port.
55 13 1 1 printer selected
64 Subdevices 0 is digital I/O, subdevice 1 is digital input, and
65 subdevice 2 is digital output. Unlike other Comedi devices,
66 subdevice 0 defaults to output.
68 Pins 13 and 14 are inverted once by Comedi and once by the
69 hardware, thus cancelling the effect.
71 Pin 1 is a strobe, thus acts like one. There's no way in software
72 to change this, at least on a standard parallel port.
74 Subdevice 3 pretends to be a digital input subdevice, but it always
75 returns 0 when read. However, if you run a command with
76 scan_begin_src=TRIG_EXT, it uses pin 10 as a external triggering
77 pin, which can be used to wake up tasks.
80 see http://www.beyondlogic.org/ for information.
81 or http://www.linux-magazin.de/ausgabe/1999/10/IO/io.html
84 #include "../comedidev.h"
85 #include <linux/interrupt.h>
86 #include <linux/ioport.h>
88 #define PARPORT_SIZE 3
94 static int parport_attach(struct comedi_device
*dev
,
95 struct comedi_devconfig
*it
);
96 static int parport_detach(struct comedi_device
*dev
);
97 static struct comedi_driver driver_parport
= {
98 .driver_name
= "comedi_parport",
99 .module
= THIS_MODULE
,
100 .attach
= parport_attach
,
101 .detach
= parport_detach
,
104 static int __init
driver_parport_init_module(void)
106 return comedi_driver_register(&driver_parport
);
109 static void __exit
driver_parport_cleanup_module(void)
111 comedi_driver_unregister(&driver_parport
);
114 module_init(driver_parport_init_module
);
115 module_exit(driver_parport_cleanup_module
);
117 struct parport_private
{
122 #define devpriv ((struct parport_private *)(dev->private))
124 static int parport_insn_a(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
125 struct comedi_insn
*insn
, unsigned int *data
)
128 devpriv
->a_data
&= ~data
[0];
129 devpriv
->a_data
|= (data
[0] & data
[1]);
131 outb(devpriv
->a_data
, dev
->iobase
+ PARPORT_A
);
134 data
[1] = inb(dev
->iobase
+ PARPORT_A
);
139 static int parport_insn_config_a(struct comedi_device
*dev
,
140 struct comedi_subdevice
*s
,
141 struct comedi_insn
*insn
, unsigned int *data
)
145 devpriv
->c_data
&= ~(1 << 5);
148 devpriv
->c_data
|= (1 << 5);
150 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
155 static int parport_insn_b(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
156 struct comedi_insn
*insn
, unsigned int *data
)
159 /* should writes be ignored? */
163 data
[1] = (inb(dev
->iobase
+ PARPORT_B
) >> 3);
168 static int parport_insn_c(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
169 struct comedi_insn
*insn
, unsigned int *data
)
173 devpriv
->c_data
&= ~data
[0];
174 devpriv
->c_data
|= (data
[0] & data
[1]);
176 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
179 data
[1] = devpriv
->c_data
& 0xf;
184 static int parport_intr_insn(struct comedi_device
*dev
,
185 struct comedi_subdevice
*s
,
186 struct comedi_insn
*insn
, unsigned int *data
)
195 static int parport_intr_cmdtest(struct comedi_device
*dev
,
196 struct comedi_subdevice
*s
,
197 struct comedi_cmd
*cmd
)
204 tmp
= cmd
->start_src
;
205 cmd
->start_src
&= TRIG_NOW
;
206 if (!cmd
->start_src
|| tmp
!= cmd
->start_src
)
209 tmp
= cmd
->scan_begin_src
;
210 cmd
->scan_begin_src
&= TRIG_EXT
;
211 if (!cmd
->scan_begin_src
|| tmp
!= cmd
->scan_begin_src
)
214 tmp
= cmd
->convert_src
;
215 cmd
->convert_src
&= TRIG_FOLLOW
;
216 if (!cmd
->convert_src
|| tmp
!= cmd
->convert_src
)
219 tmp
= cmd
->scan_end_src
;
220 cmd
->scan_end_src
&= TRIG_COUNT
;
221 if (!cmd
->scan_end_src
|| tmp
!= cmd
->scan_end_src
)
225 cmd
->stop_src
&= TRIG_NONE
;
226 if (!cmd
->stop_src
|| tmp
!= cmd
->stop_src
)
232 /* step 2: ignored */
239 if (cmd
->start_arg
!= 0) {
243 if (cmd
->scan_begin_arg
!= 0) {
244 cmd
->scan_begin_arg
= 0;
247 if (cmd
->convert_arg
!= 0) {
248 cmd
->convert_arg
= 0;
251 if (cmd
->scan_end_arg
!= 1) {
252 cmd
->scan_end_arg
= 1;
255 if (cmd
->stop_arg
!= 0) {
263 /* step 4: ignored */
271 static int parport_intr_cmd(struct comedi_device
*dev
,
272 struct comedi_subdevice
*s
)
274 devpriv
->c_data
|= 0x10;
275 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
277 devpriv
->enable_irq
= 1;
282 static int parport_intr_cancel(struct comedi_device
*dev
,
283 struct comedi_subdevice
*s
)
285 printk(KERN_DEBUG
"parport_intr_cancel()\n");
287 devpriv
->c_data
&= ~0x10;
288 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
290 devpriv
->enable_irq
= 0;
295 static irqreturn_t
parport_interrupt(int irq
, void *d
)
297 struct comedi_device
*dev
= d
;
298 struct comedi_subdevice
*s
= dev
->subdevices
+ 3;
300 if (!devpriv
->enable_irq
) {
301 printk(KERN_ERR
"comedi_parport: bogus irq, ignored\n");
305 comedi_buf_put(s
->async
, 0);
306 s
->async
->events
|= COMEDI_CB_BLOCK
| COMEDI_CB_EOS
;
308 comedi_event(dev
, s
);
312 static int parport_attach(struct comedi_device
*dev
,
313 struct comedi_devconfig
*it
)
317 unsigned long iobase
;
318 struct comedi_subdevice
*s
;
320 iobase
= it
->options
[0];
321 printk(KERN_INFO
"comedi%d: parport: 0x%04lx ", dev
->minor
, iobase
);
322 if (!request_region(iobase
, PARPORT_SIZE
, "parport (comedi)")) {
323 printk(KERN_ERR
"I/O port conflict\n");
326 dev
->iobase
= iobase
;
328 irq
= it
->options
[1];
330 printk(KERN_INFO
" irq=%u", irq
);
331 ret
= request_irq(irq
, parport_interrupt
, 0, "comedi_parport",
334 printk(KERN_ERR
" irq not available\n");
339 dev
->board_name
= "parport";
341 ret
= alloc_subdevices(dev
, 4);
344 ret
= alloc_private(dev
, sizeof(struct parport_private
));
348 s
= dev
->subdevices
+ 0;
349 s
->type
= COMEDI_SUBD_DIO
;
350 s
->subdev_flags
= SDF_READABLE
| SDF_WRITABLE
;
353 s
->range_table
= &range_digital
;
354 s
->insn_bits
= parport_insn_a
;
355 s
->insn_config
= parport_insn_config_a
;
357 s
= dev
->subdevices
+ 1;
358 s
->type
= COMEDI_SUBD_DI
;
359 s
->subdev_flags
= SDF_READABLE
;
362 s
->range_table
= &range_digital
;
363 s
->insn_bits
= parport_insn_b
;
365 s
= dev
->subdevices
+ 2;
366 s
->type
= COMEDI_SUBD_DO
;
367 s
->subdev_flags
= SDF_WRITABLE
;
370 s
->range_table
= &range_digital
;
371 s
->insn_bits
= parport_insn_c
;
373 s
= dev
->subdevices
+ 3;
375 dev
->read_subdev
= s
;
376 s
->type
= COMEDI_SUBD_DI
;
377 s
->subdev_flags
= SDF_READABLE
| SDF_CMD_READ
;
380 s
->range_table
= &range_digital
;
381 s
->insn_bits
= parport_intr_insn
;
382 s
->do_cmdtest
= parport_intr_cmdtest
;
383 s
->do_cmd
= parport_intr_cmd
;
384 s
->cancel
= parport_intr_cancel
;
386 s
->type
= COMEDI_SUBD_UNUSED
;
390 outb(devpriv
->a_data
, dev
->iobase
+ PARPORT_A
);
392 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
394 printk(KERN_INFO
"\n");
398 static int parport_detach(struct comedi_device
*dev
)
400 printk(KERN_INFO
"comedi%d: parport: remove\n", dev
->minor
);
403 release_region(dev
->iobase
, PARPORT_SIZE
);
406 free_irq(dev
->irq
, dev
);
411 MODULE_AUTHOR("Comedi http://www.comedi.org");
412 MODULE_DESCRIPTION("Comedi low-level driver");
413 MODULE_LICENSE("GPL");