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 #include "comedi_fc.h"
90 #define PARPORT_SIZE 3
96 struct parport_private
{
102 static int parport_insn_a(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
103 struct comedi_insn
*insn
, unsigned int *data
)
105 struct parport_private
*devpriv
= dev
->private;
108 devpriv
->a_data
&= ~data
[0];
109 devpriv
->a_data
|= (data
[0] & data
[1]);
111 outb(devpriv
->a_data
, dev
->iobase
+ PARPORT_A
);
114 data
[1] = inb(dev
->iobase
+ PARPORT_A
);
119 static int parport_insn_config_a(struct comedi_device
*dev
,
120 struct comedi_subdevice
*s
,
121 struct comedi_insn
*insn
, unsigned int *data
)
123 struct parport_private
*devpriv
= dev
->private;
127 devpriv
->c_data
&= ~(1 << 5);
130 devpriv
->c_data
|= (1 << 5);
132 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
137 static int parport_insn_b(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
138 struct comedi_insn
*insn
, unsigned int *data
)
141 /* should writes be ignored? */
145 data
[1] = (inb(dev
->iobase
+ PARPORT_B
) >> 3);
150 static int parport_insn_c(struct comedi_device
*dev
, struct comedi_subdevice
*s
,
151 struct comedi_insn
*insn
, unsigned int *data
)
153 struct parport_private
*devpriv
= dev
->private;
157 devpriv
->c_data
&= ~data
[0];
158 devpriv
->c_data
|= (data
[0] & data
[1]);
160 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
163 data
[1] = devpriv
->c_data
& 0xf;
168 static int parport_intr_insn(struct comedi_device
*dev
,
169 struct comedi_subdevice
*s
,
170 struct comedi_insn
*insn
, unsigned int *data
)
176 static int parport_intr_cmdtest(struct comedi_device
*dev
,
177 struct comedi_subdevice
*s
,
178 struct comedi_cmd
*cmd
)
182 /* Step 1 : check if triggers are trivially valid */
184 err
|= cfc_check_trigger_src(&cmd
->start_src
, TRIG_NOW
);
185 err
|= cfc_check_trigger_src(&cmd
->scan_begin_src
, TRIG_EXT
);
186 err
|= cfc_check_trigger_src(&cmd
->convert_src
, TRIG_FOLLOW
);
187 err
|= cfc_check_trigger_src(&cmd
->scan_end_src
, TRIG_COUNT
);
188 err
|= cfc_check_trigger_src(&cmd
->stop_src
, TRIG_NONE
);
193 /* Step 2a : make sure trigger sources are unique */
194 /* Step 2b : and mutually compatible */
201 if (cmd
->start_arg
!= 0) {
205 if (cmd
->scan_begin_arg
!= 0) {
206 cmd
->scan_begin_arg
= 0;
209 if (cmd
->convert_arg
!= 0) {
210 cmd
->convert_arg
= 0;
213 if (cmd
->scan_end_arg
!= 1) {
214 cmd
->scan_end_arg
= 1;
217 if (cmd
->stop_arg
!= 0) {
225 /* step 4: ignored */
233 static int parport_intr_cmd(struct comedi_device
*dev
,
234 struct comedi_subdevice
*s
)
236 struct parport_private
*devpriv
= dev
->private;
238 devpriv
->c_data
|= 0x10;
239 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
241 devpriv
->enable_irq
= 1;
246 static int parport_intr_cancel(struct comedi_device
*dev
,
247 struct comedi_subdevice
*s
)
249 struct parport_private
*devpriv
= dev
->private;
251 devpriv
->c_data
&= ~0x10;
252 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
254 devpriv
->enable_irq
= 0;
259 static irqreturn_t
parport_interrupt(int irq
, void *d
)
261 struct comedi_device
*dev
= d
;
262 struct parport_private
*devpriv
= dev
->private;
263 struct comedi_subdevice
*s
= &dev
->subdevices
[3];
265 if (!devpriv
->enable_irq
)
268 comedi_buf_put(s
->async
, 0);
269 s
->async
->events
|= COMEDI_CB_BLOCK
| COMEDI_CB_EOS
;
271 comedi_event(dev
, s
);
275 static int parport_attach(struct comedi_device
*dev
,
276 struct comedi_devconfig
*it
)
278 struct parport_private
*devpriv
;
281 unsigned long iobase
;
282 struct comedi_subdevice
*s
;
284 dev
->board_name
= dev
->driver
->driver_name
;
286 iobase
= it
->options
[0];
287 if (!request_region(iobase
, PARPORT_SIZE
, dev
->board_name
)) {
288 dev_err(dev
->class_dev
, "I/O port conflict\n");
291 dev
->iobase
= iobase
;
293 irq
= it
->options
[1];
295 ret
= request_irq(irq
, parport_interrupt
, 0, dev
->board_name
,
298 dev_err(dev
->class_dev
, "irq not available\n");
304 ret
= comedi_alloc_subdevices(dev
, 4);
308 ret
= alloc_private(dev
, sizeof(*devpriv
));
311 devpriv
= dev
->private;
313 s
= &dev
->subdevices
[0];
314 s
->type
= COMEDI_SUBD_DIO
;
315 s
->subdev_flags
= SDF_READABLE
| SDF_WRITABLE
;
318 s
->range_table
= &range_digital
;
319 s
->insn_bits
= parport_insn_a
;
320 s
->insn_config
= parport_insn_config_a
;
322 s
= &dev
->subdevices
[1];
323 s
->type
= COMEDI_SUBD_DI
;
324 s
->subdev_flags
= SDF_READABLE
;
327 s
->range_table
= &range_digital
;
328 s
->insn_bits
= parport_insn_b
;
330 s
= &dev
->subdevices
[2];
331 s
->type
= COMEDI_SUBD_DO
;
332 s
->subdev_flags
= SDF_WRITABLE
;
335 s
->range_table
= &range_digital
;
336 s
->insn_bits
= parport_insn_c
;
338 s
= &dev
->subdevices
[3];
340 dev
->read_subdev
= s
;
341 s
->type
= COMEDI_SUBD_DI
;
342 s
->subdev_flags
= SDF_READABLE
| SDF_CMD_READ
;
345 s
->range_table
= &range_digital
;
346 s
->insn_bits
= parport_intr_insn
;
347 s
->do_cmdtest
= parport_intr_cmdtest
;
348 s
->do_cmd
= parport_intr_cmd
;
349 s
->cancel
= parport_intr_cancel
;
351 s
->type
= COMEDI_SUBD_UNUSED
;
355 outb(devpriv
->a_data
, dev
->iobase
+ PARPORT_A
);
357 outb(devpriv
->c_data
, dev
->iobase
+ PARPORT_C
);
359 dev_info(dev
->class_dev
, "%s: iobase=0x%04lx, irq %sabled",
360 dev
->board_name
, dev
->iobase
, dev
->irq
? "en" : "dis");
365 static void parport_detach(struct comedi_device
*dev
)
368 release_region(dev
->iobase
, PARPORT_SIZE
);
370 free_irq(dev
->irq
, dev
);
373 static struct comedi_driver parport_driver
= {
374 .driver_name
= "comedi_parport",
375 .module
= THIS_MODULE
,
376 .attach
= parport_attach
,
377 .detach
= parport_detach
,
379 module_comedi_driver(parport_driver
);
381 MODULE_AUTHOR("Comedi http://www.comedi.org");
382 MODULE_DESCRIPTION("Comedi low-level driver");
383 MODULE_LICENSE("GPL");