comedi_parport.c revision 5f74ea14c07fee91d3bdbaad88bff6264c6200e6 
1/*
2    comedi/drivers/comedi_parport.c
3    hardware driver for standard parallel port
4
5    COMEDI - Linux Control and Measurement Device Interface
6    Copyright (C) 1998,2001 David A. Schleef <ds@schleef.org>
7
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.
12
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.
17
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.
21
22*/
23/*
24Driver: comedi_parport
25Description: Standard PC parallel port
26Author: ds
27Status: works in immediate mode
28Devices: [standard] parallel port (comedi_parport)
29Updated: Tue, 30 Apr 2002 21:11:45 -0700
30
31A cheap and easy way to get a few more digital I/O lines.  Steal
32additional parallel ports from old computers or your neighbors'
33computers.
34
35Option list:
36 0: I/O port base for the parallel port.
37 1: IRQ
38
39Parallel Port Lines:
40
41pin     subdev  chan    aka
42---     ------  ----    ---
431       2       0       strobe
442       0       0       data 0
453       0       1       data 1
464       0       2       data 2
475       0       3       data 3
486       0       4       data 4
497       0       5       data 5
508       0       6       data 6
519       0       7       data 7
5210      1       3       acknowledge
5311      1       4       busy
5412      1       2       output
5513      1       1       printer selected
5614      2       1       auto LF
5715      1       0       error
5816      2       2       init
5917      2       3       select printer
6018-25   ground
61
62Notes:
63
64Subdevices 0 is digital I/O, subdevice 1 is digital input, and
65subdevice 2 is digital output.  Unlike other Comedi devices,
66subdevice 0 defaults to output.
67
68Pins 13 and 14 are inverted once by Comedi and once by the
69hardware, thus cancelling the effect.
70
71Pin 1 is a strobe, thus acts like one.  There's no way in software
72to change this, at least on a standard parallel port.
73
74Subdevice 3 pretends to be a digital input subdevice, but it always
75returns 0 when read.  However, if you run a command with
76scan_begin_src=TRIG_EXT, it uses pin 10 as a external triggering
77pin, which can be used to wake up tasks.
78*/
79/*
80   see http://www.beyondlogic.org/ for information.
81   or http://www.linux-magazin.de/ausgabe/1999/10/IO/io.html
82 */
83
84#include "../comedidev.h"
85#include <linux/interrupt.h>
86#include <linux/ioport.h>
87
88#define PARPORT_SIZE 3
89
90#define PARPORT_A 0
91#define PARPORT_B 1
92#define PARPORT_C 2
93
94static int parport_attach(struct comedi_device *dev, struct comedi_devconfig *it);
95static int parport_detach(struct comedi_device *dev);
96static struct comedi_driver driver_parport = {
97      .driver_name =	"comedi_parport",
98      .module =		THIS_MODULE,
99      .attach =		parport_attach,
100      .detach =		parport_detach,
101};
102
103COMEDI_INITCLEANUP(driver_parport);
104
105struct parport_private {
106	unsigned int a_data;
107	unsigned int c_data;
108	int enable_irq;
109};
110#define devpriv ((struct parport_private *)(dev->private))
111
112static int parport_insn_a(struct comedi_device *dev, struct comedi_subdevice *s,
113			  struct comedi_insn *insn, unsigned int *data)
114{
115	if (data[0]) {
116		devpriv->a_data &= ~data[0];
117		devpriv->a_data |= (data[0] & data[1]);
118
119		outb(devpriv->a_data, dev->iobase + PARPORT_A);
120	}
121
122	data[1] = inb(dev->iobase + PARPORT_A);
123
124	return 2;
125}
126
127static int parport_insn_config_a(struct comedi_device *dev, struct comedi_subdevice *s,
128				 struct comedi_insn *insn, unsigned int *data)
129{
130	if (data[0]) {
131		s->io_bits = 0xff;
132		devpriv->c_data &= ~(1 << 5);
133	} else {
134		s->io_bits = 0;
135		devpriv->c_data |= (1 << 5);
136	}
137	outb(devpriv->c_data, dev->iobase + PARPORT_C);
138
139	return 1;
140}
141
142static int parport_insn_b(struct comedi_device *dev, struct comedi_subdevice *s,
143			  struct comedi_insn *insn, unsigned int *data)
144{
145	if (data[0]) {
146		/* should writes be ignored? */
147		/* anyone??? */
148	}
149
150	data[1] = (inb(dev->iobase + PARPORT_B) >> 3);
151
152	return 2;
153}
154
155static int parport_insn_c(struct comedi_device *dev, struct comedi_subdevice *s,
156			  struct comedi_insn *insn, unsigned int *data)
157{
158	data[0] &= 0x0f;
159	if (data[0]) {
160		devpriv->c_data &= ~data[0];
161		devpriv->c_data |= (data[0] & data[1]);
162
163		outb(devpriv->c_data, dev->iobase + PARPORT_C);
164	}
165
166	data[1] = devpriv->c_data & 0xf;
167
168	return 2;
169}
170
171static int parport_intr_insn(struct comedi_device *dev, struct comedi_subdevice *s,
172			     struct comedi_insn *insn, unsigned int *data)
173{
174	if (insn->n < 1)
175		return -EINVAL;
176
177	data[1] = 0;
178	return 2;
179}
180
181static int parport_intr_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
182				struct comedi_cmd *cmd)
183{
184	int err = 0;
185	int tmp;
186
187	/* step 1 */
188
189	tmp = cmd->start_src;
190	cmd->start_src &= TRIG_NOW;
191	if (!cmd->start_src || tmp != cmd->start_src)
192		err++;
193
194	tmp = cmd->scan_begin_src;
195	cmd->scan_begin_src &= TRIG_EXT;
196	if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
197		err++;
198
199	tmp = cmd->convert_src;
200	cmd->convert_src &= TRIG_FOLLOW;
201	if (!cmd->convert_src || tmp != cmd->convert_src)
202		err++;
203
204	tmp = cmd->scan_end_src;
205	cmd->scan_end_src &= TRIG_COUNT;
206	if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
207		err++;
208
209	tmp = cmd->stop_src;
210	cmd->stop_src &= TRIG_NONE;
211	if (!cmd->stop_src || tmp != cmd->stop_src)
212		err++;
213
214	if (err)
215		return 1;
216
217	/* step 2: ignored */
218
219	if (err)
220		return 2;
221
222	/* step 3: */
223
224	if (cmd->start_arg != 0) {
225		cmd->start_arg = 0;
226		err++;
227	}
228	if (cmd->scan_begin_arg != 0) {
229		cmd->scan_begin_arg = 0;
230		err++;
231	}
232	if (cmd->convert_arg != 0) {
233		cmd->convert_arg = 0;
234		err++;
235	}
236	if (cmd->scan_end_arg != 1) {
237		cmd->scan_end_arg = 1;
238		err++;
239	}
240	if (cmd->stop_arg != 0) {
241		cmd->stop_arg = 0;
242		err++;
243	}
244
245	if (err)
246		return 3;
247
248	/* step 4: ignored */
249
250	if (err)
251		return 4;
252
253	return 0;
254}
255
256static int parport_intr_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
257{
258	devpriv->c_data |= 0x10;
259	outb(devpriv->c_data, dev->iobase + PARPORT_C);
260
261	devpriv->enable_irq = 1;
262
263	return 0;
264}
265
266static int parport_intr_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
267{
268	printk(KERN_DEBUG "parport_intr_cancel()\n");
269
270	devpriv->c_data &= ~0x10;
271	outb(devpriv->c_data, dev->iobase + PARPORT_C);
272
273	devpriv->enable_irq = 0;
274
275	return 0;
276}
277
278static irqreturn_t parport_interrupt(int irq, void *d)
279{
280	struct comedi_device *dev = d;
281	struct comedi_subdevice *s = dev->subdevices + 3;
282
283	if (!devpriv->enable_irq) {
284		printk(KERN_ERR "comedi_parport: bogus irq, ignored\n");
285		return IRQ_NONE;
286	}
287
288	comedi_buf_put(s->async, 0);
289	s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
290
291	comedi_event(dev, s);
292	return IRQ_HANDLED;
293}
294
295static int parport_attach(struct comedi_device *dev, struct comedi_devconfig *it)
296{
297	int ret;
298	unsigned int irq;
299	unsigned long iobase;
300	struct comedi_subdevice *s;
301
302	iobase = it->options[0];
303	printk(KERN_INFO "comedi%d: parport: 0x%04lx ", dev->minor, iobase);
304	if (!request_region(iobase, PARPORT_SIZE, "parport (comedi)")) {
305		printk("I/O port conflict\n");
306		return -EIO;
307	}
308	dev->iobase = iobase;
309
310	irq = it->options[1];
311	if (irq) {
312		printk(" irq=%u", irq);
313		ret = request_irq(irq, parport_interrupt, 0, "comedi_parport",
314				  dev);
315		if (ret < 0) {
316			printk(" irq not available\n");
317			return -EINVAL;
318		}
319		dev->irq = irq;
320	}
321	dev->board_name = "parport";
322
323	ret = alloc_subdevices(dev, 4);
324	if (ret < 0)
325		return ret;
326	ret = alloc_private(dev, sizeof(struct parport_private));
327	if (ret < 0)
328		return ret;
329
330	s = dev->subdevices + 0;
331	s->type = COMEDI_SUBD_DIO;
332	s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
333	s->n_chan = 8;
334	s->maxdata = 1;
335	s->range_table = &range_digital;
336	s->insn_bits = parport_insn_a;
337	s->insn_config = parport_insn_config_a;
338
339	s = dev->subdevices + 1;
340	s->type = COMEDI_SUBD_DI;
341	s->subdev_flags = SDF_READABLE;
342	s->n_chan = 5;
343	s->maxdata = 1;
344	s->range_table = &range_digital;
345	s->insn_bits = parport_insn_b;
346
347	s = dev->subdevices + 2;
348	s->type = COMEDI_SUBD_DO;
349	s->subdev_flags = SDF_WRITABLE;
350	s->n_chan = 4;
351	s->maxdata = 1;
352	s->range_table = &range_digital;
353	s->insn_bits = parport_insn_c;
354
355	s = dev->subdevices + 3;
356	if (irq) {
357		dev->read_subdev = s;
358		s->type = COMEDI_SUBD_DI;
359		s->subdev_flags = SDF_READABLE | SDF_CMD_READ;
360		s->n_chan = 1;
361		s->maxdata = 1;
362		s->range_table = &range_digital;
363		s->insn_bits = parport_intr_insn;
364		s->do_cmdtest = parport_intr_cmdtest;
365		s->do_cmd = parport_intr_cmd;
366		s->cancel = parport_intr_cancel;
367	} else {
368		s->type = COMEDI_SUBD_UNUSED;
369	}
370
371	devpriv->a_data = 0;
372	outb(devpriv->a_data, dev->iobase + PARPORT_A);
373	devpriv->c_data = 0;
374	outb(devpriv->c_data, dev->iobase + PARPORT_C);
375
376	printk("\n");
377	return 1;
378}
379
380static int parport_detach(struct comedi_device *dev)
381{
382	printk("comedi%d: parport: remove\n", dev->minor);
383
384	if (dev->iobase)
385		release_region(dev->iobase, PARPORT_SIZE);
386
387	if (dev->irq)
388		free_irq(dev->irq, dev);
389
390	return 0;
391}
392