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 struct parport_private {
99 #define devpriv ((struct parport_private *)(dev->private))
101 static int parport_insn_a(struct comedi_device *dev, struct comedi_subdevice *s,
102 struct comedi_insn *insn, unsigned int *data)
105 devpriv->a_data &= ~data[0];
106 devpriv->a_data |= (data[0] & data[1]);
108 outb(devpriv->a_data, dev->iobase + PARPORT_A);
111 data[1] = inb(dev->iobase + PARPORT_A);
116 static int parport_insn_config_a(struct comedi_device *dev,
117 struct comedi_subdevice *s,
118 struct comedi_insn *insn, unsigned int *data)
122 devpriv->c_data &= ~(1 << 5);
125 devpriv->c_data |= (1 << 5);
127 outb(devpriv->c_data, dev->iobase + PARPORT_C);
132 static int parport_insn_b(struct comedi_device *dev, struct comedi_subdevice *s,
133 struct comedi_insn *insn, unsigned int *data)
136 /* should writes be ignored? */
140 data[1] = (inb(dev->iobase + PARPORT_B) >> 3);
145 static int parport_insn_c(struct comedi_device *dev, struct comedi_subdevice *s,
146 struct comedi_insn *insn, unsigned int *data)
150 devpriv->c_data &= ~data[0];
151 devpriv->c_data |= (data[0] & data[1]);
153 outb(devpriv->c_data, dev->iobase + PARPORT_C);
156 data[1] = devpriv->c_data & 0xf;
161 static int parport_intr_insn(struct comedi_device *dev,
162 struct comedi_subdevice *s,
163 struct comedi_insn *insn, unsigned int *data)
169 static int parport_intr_cmdtest(struct comedi_device *dev,
170 struct comedi_subdevice *s,
171 struct comedi_cmd *cmd)
178 tmp = cmd->start_src;
179 cmd->start_src &= TRIG_NOW;
180 if (!cmd->start_src || tmp != cmd->start_src)
183 tmp = cmd->scan_begin_src;
184 cmd->scan_begin_src &= TRIG_EXT;
185 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
188 tmp = cmd->convert_src;
189 cmd->convert_src &= TRIG_FOLLOW;
190 if (!cmd->convert_src || tmp != cmd->convert_src)
193 tmp = cmd->scan_end_src;
194 cmd->scan_end_src &= TRIG_COUNT;
195 if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
199 cmd->stop_src &= TRIG_NONE;
200 if (!cmd->stop_src || tmp != cmd->stop_src)
206 /* step 2: ignored */
213 if (cmd->start_arg != 0) {
217 if (cmd->scan_begin_arg != 0) {
218 cmd->scan_begin_arg = 0;
221 if (cmd->convert_arg != 0) {
222 cmd->convert_arg = 0;
225 if (cmd->scan_end_arg != 1) {
226 cmd->scan_end_arg = 1;
229 if (cmd->stop_arg != 0) {
237 /* step 4: ignored */
245 static int parport_intr_cmd(struct comedi_device *dev,
246 struct comedi_subdevice *s)
248 devpriv->c_data |= 0x10;
249 outb(devpriv->c_data, dev->iobase + PARPORT_C);
251 devpriv->enable_irq = 1;
256 static int parport_intr_cancel(struct comedi_device *dev,
257 struct comedi_subdevice *s)
259 printk(KERN_DEBUG "parport_intr_cancel()\n");
261 devpriv->c_data &= ~0x10;
262 outb(devpriv->c_data, dev->iobase + PARPORT_C);
264 devpriv->enable_irq = 0;
269 static irqreturn_t parport_interrupt(int irq, void *d)
271 struct comedi_device *dev = d;
272 struct comedi_subdevice *s = dev->subdevices + 3;
274 if (!devpriv->enable_irq) {
275 printk(KERN_ERR "comedi_parport: bogus irq, ignored\n");
279 comedi_buf_put(s->async, 0);
280 s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
282 comedi_event(dev, s);
286 static int parport_attach(struct comedi_device *dev,
287 struct comedi_devconfig *it)
291 unsigned long iobase;
292 struct comedi_subdevice *s;
294 iobase = it->options[0];
295 printk(KERN_INFO "comedi%d: parport: 0x%04lx ", dev->minor, iobase);
296 if (!request_region(iobase, PARPORT_SIZE, "parport (comedi)")) {
297 printk(KERN_ERR "I/O port conflict\n");
300 dev->iobase = iobase;
302 irq = it->options[1];
304 printk(KERN_INFO " irq=%u", irq);
305 ret = request_irq(irq, parport_interrupt, 0, "comedi_parport",
308 printk(KERN_ERR " irq not available\n");
313 dev->board_name = "parport";
315 ret = comedi_alloc_subdevices(dev, 4);
319 ret = alloc_private(dev, sizeof(struct parport_private));
323 s = dev->subdevices + 0;
324 s->type = COMEDI_SUBD_DIO;
325 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
328 s->range_table = &range_digital;
329 s->insn_bits = parport_insn_a;
330 s->insn_config = parport_insn_config_a;
332 s = dev->subdevices + 1;
333 s->type = COMEDI_SUBD_DI;
334 s->subdev_flags = SDF_READABLE;
337 s->range_table = &range_digital;
338 s->insn_bits = parport_insn_b;
340 s = dev->subdevices + 2;
341 s->type = COMEDI_SUBD_DO;
342 s->subdev_flags = SDF_WRITABLE;
345 s->range_table = &range_digital;
346 s->insn_bits = parport_insn_c;
348 s = dev->subdevices + 3;
350 dev->read_subdev = s;
351 s->type = COMEDI_SUBD_DI;
352 s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
355 s->range_table = &range_digital;
356 s->insn_bits = parport_intr_insn;
357 s->do_cmdtest = parport_intr_cmdtest;
358 s->do_cmd = parport_intr_cmd;
359 s->cancel = parport_intr_cancel;
361 s->type = COMEDI_SUBD_UNUSED;
365 outb(devpriv->a_data, dev->iobase + PARPORT_A);
367 outb(devpriv->c_data, dev->iobase + PARPORT_C);
369 printk(KERN_INFO "\n");
373 static void parport_detach(struct comedi_device *dev)
376 release_region(dev->iobase, PARPORT_SIZE);
378 free_irq(dev->irq, dev);
381 static struct comedi_driver parport_driver = {
382 .driver_name = "comedi_parport",
383 .module = THIS_MODULE,
384 .attach = parport_attach,
385 .detach = parport_detach,
387 module_comedi_driver(parport_driver);
389 MODULE_AUTHOR("Comedi http://www.comedi.org");
390 MODULE_DESCRIPTION("Comedi low-level driver");
391 MODULE_LICENSE("GPL");