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 */
199 /* Step 3: check if arguments are trivially valid */
201 err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
202 err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
203 err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
204 err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
205 err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
210 /* step 4: ignored */
218 static int parport_intr_cmd(struct comedi_device *dev,
219 struct comedi_subdevice *s)
221 struct parport_private *devpriv = dev->private;
223 devpriv->c_data |= 0x10;
224 outb(devpriv->c_data, dev->iobase + PARPORT_C);
226 devpriv->enable_irq = 1;
231 static int parport_intr_cancel(struct comedi_device *dev,
232 struct comedi_subdevice *s)
234 struct parport_private *devpriv = dev->private;
236 devpriv->c_data &= ~0x10;
237 outb(devpriv->c_data, dev->iobase + PARPORT_C);
239 devpriv->enable_irq = 0;
244 static irqreturn_t parport_interrupt(int irq, void *d)
246 struct comedi_device *dev = d;
247 struct parport_private *devpriv = dev->private;
248 struct comedi_subdevice *s = &dev->subdevices[3];
250 if (!devpriv->enable_irq)
253 comedi_buf_put(s->async, 0);
254 s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
256 comedi_event(dev, s);
260 static int parport_attach(struct comedi_device *dev,
261 struct comedi_devconfig *it)
263 struct parport_private *devpriv;
264 struct comedi_subdevice *s;
268 ret = comedi_request_region(dev, it->options[0], PARPORT_SIZE);
272 irq = it->options[1];
274 ret = request_irq(irq, parport_interrupt, 0, dev->board_name,
277 dev_err(dev->class_dev, "irq not available\n");
283 ret = comedi_alloc_subdevices(dev, 4);
287 devpriv = kzalloc(sizeof(*devpriv), GFP_KERNEL);
290 dev->private = devpriv;
292 s = &dev->subdevices[0];
293 s->type = COMEDI_SUBD_DIO;
294 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
297 s->range_table = &range_digital;
298 s->insn_bits = parport_insn_a;
299 s->insn_config = parport_insn_config_a;
301 s = &dev->subdevices[1];
302 s->type = COMEDI_SUBD_DI;
303 s->subdev_flags = SDF_READABLE;
306 s->range_table = &range_digital;
307 s->insn_bits = parport_insn_b;
309 s = &dev->subdevices[2];
310 s->type = COMEDI_SUBD_DO;
311 s->subdev_flags = SDF_WRITABLE;
314 s->range_table = &range_digital;
315 s->insn_bits = parport_insn_c;
317 s = &dev->subdevices[3];
319 dev->read_subdev = s;
320 s->type = COMEDI_SUBD_DI;
321 s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
324 s->range_table = &range_digital;
325 s->insn_bits = parport_intr_insn;
326 s->do_cmdtest = parport_intr_cmdtest;
327 s->do_cmd = parport_intr_cmd;
328 s->cancel = parport_intr_cancel;
330 s->type = COMEDI_SUBD_UNUSED;
334 outb(devpriv->a_data, dev->iobase + PARPORT_A);
336 outb(devpriv->c_data, dev->iobase + PARPORT_C);
341 static struct comedi_driver parport_driver = {
342 .driver_name = "comedi_parport",
343 .module = THIS_MODULE,
344 .attach = parport_attach,
345 .detach = comedi_legacy_detach,
347 module_comedi_driver(parport_driver);
349 MODULE_AUTHOR("Comedi http://www.comedi.org");
350 MODULE_DESCRIPTION("Comedi low-level driver");
351 MODULE_LICENSE("GPL");