5 COMEDI - Linux Control and Measurement Device Interface
6 Copyright (C) 1998 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.
25 Description: generic 8255 support
26 Devices: [standard] 8255 (8255)
29 Updated: Fri, 7 Jun 2002 12:56:45 -0700
31 The classic in digital I/O. The 8255 appears in Comedi as a single
32 digital I/O subdevice with 24 channels. The channel 0 corresponds
33 to the 8255's port A, bit 0; channel 23 corresponds to port C, bit
34 7. Direction configuration is done in blocks, with channels 0-7,
35 8-15, 16-19, and 20-23 making up the 4 blocks. The only 8255 mode
38 You should enable compilation this driver if you plan to use a board
39 that has an 8255 chip. For multifunction boards, the main driver will
40 configure the 8255 subdevice automatically.
42 This driver also works independently with ISA and PCI cards that
43 directly map the 8255 registers to I/O ports, including cards with
44 multiple 8255 chips. To configure the driver for such a card, the
45 option list should be a list of the I/O port bases for each of the
46 8255 chips. For example,
48 comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c
50 Note that most PCI 8255 boards do NOT work with this driver, and
51 need a separate driver as a wrapper. For those that do work, the
52 I/O port base address can be found in the output of 'lspci -v'.
57 This file contains an exported subdevice for driving an 8255.
59 To use this subdevice as part of another driver, you need to
60 set up the subdevice in the attach function of the driver by
63 subdev_8255_init(device, subdevice, io_function, iobase)
65 device and subdevice are pointers to the device and subdevice
66 structures. io_function will be called to provide the
67 low-level input/output to the device, i.e., actual register
68 access. io_function will be called with the value of iobase
69 as the last parameter. If the 8255 device is mapped as 4
70 consecutive I/O ports, you can use NULL for io_function
71 and the I/O port base for iobase, and an internal function will
72 handle the register access.
74 In addition, if the main driver handles interrupts, you can
75 enable commands on the subdevice by calling subdev_8255_init_irq()
76 instead. Then, when you get an interrupt that is likely to be
77 from the 8255, you should call subdev_8255_interrupt(), which
78 will copy the latched value to a Comedi buffer.
81 #include "../comedidev.h"
83 #include <linux/ioport.h>
84 #include <linux/slab.h>
92 #define CR_C_LO_IO 0x01
94 #define CR_B_MODE 0x04
95 #define CR_C_HI_IO 0x08
97 #define CR_A_MODE(a) ((a)<<5)
100 struct subdev_8255_private {
101 unsigned long iobase;
102 int (*io) (int, int, int, unsigned long);
105 static int subdev_8255_io(int dir, int port, int data, unsigned long iobase)
108 outb(data, iobase + port);
111 return inb(iobase + port);
115 void subdev_8255_interrupt(struct comedi_device *dev,
116 struct comedi_subdevice *s)
118 struct subdev_8255_private *spriv = s->private;
119 unsigned long iobase = spriv->iobase;
122 d = spriv->io(0, _8255_DATA, 0, iobase);
123 d |= (spriv->io(0, _8255_DATA + 1, 0, iobase) << 8);
125 comedi_buf_put(s->async, d);
126 s->async->events |= COMEDI_CB_EOS;
128 comedi_event(dev, s);
130 EXPORT_SYMBOL(subdev_8255_interrupt);
132 static int subdev_8255_insn(struct comedi_device *dev,
133 struct comedi_subdevice *s,
134 struct comedi_insn *insn, unsigned int *data)
136 struct subdev_8255_private *spriv = s->private;
137 unsigned long iobase = spriv->iobase;
151 spriv->io(1, _8255_DATA, v & 0xff, iobase);
153 spriv->io(1, _8255_DATA + 1, (v >> 8) & 0xff, iobase);
155 spriv->io(1, _8255_DATA + 2, (v >> 16) & 0xff, iobase);
160 v = spriv->io(0, _8255_DATA, 0, iobase);
161 v |= (spriv->io(0, _8255_DATA + 1, 0, iobase) << 8);
162 v |= (spriv->io(0, _8255_DATA + 2, 0, iobase) << 16);
169 static void subdev_8255_do_config(struct comedi_device *dev,
170 struct comedi_subdevice *s)
172 struct subdev_8255_private *spriv = s->private;
173 unsigned long iobase = spriv->iobase;
177 /* 1 in io_bits indicates output, 1 in config indicates input */
178 if (!(s->io_bits & 0x0000ff))
180 if (!(s->io_bits & 0x00ff00))
182 if (!(s->io_bits & 0x0f0000))
183 config |= CR_C_LO_IO;
184 if (!(s->io_bits & 0xf00000))
185 config |= CR_C_HI_IO;
187 spriv->io(1, _8255_CR, config, iobase);
190 static int subdev_8255_insn_config(struct comedi_device *dev,
191 struct comedi_subdevice *s,
192 struct comedi_insn *insn, unsigned int *data)
197 mask = 1 << CR_CHAN(insn->chanspec);
200 else if (mask & 0x00ff00)
202 else if (mask & 0x0f0000)
208 case INSN_CONFIG_DIO_INPUT:
211 case INSN_CONFIG_DIO_OUTPUT:
214 case INSN_CONFIG_DIO_QUERY:
215 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;
222 subdev_8255_do_config(dev, s);
227 static int subdev_8255_cmdtest(struct comedi_device *dev,
228 struct comedi_subdevice *s,
229 struct comedi_cmd *cmd)
236 tmp = cmd->start_src;
237 cmd->start_src &= TRIG_NOW;
238 if (!cmd->start_src || tmp != cmd->start_src)
241 tmp = cmd->scan_begin_src;
242 cmd->scan_begin_src &= TRIG_EXT;
243 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
246 tmp = cmd->convert_src;
247 cmd->convert_src &= TRIG_FOLLOW;
248 if (!cmd->convert_src || tmp != cmd->convert_src)
251 tmp = cmd->scan_end_src;
252 cmd->scan_end_src &= TRIG_COUNT;
253 if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
257 cmd->stop_src &= TRIG_NONE;
258 if (!cmd->stop_src || tmp != cmd->stop_src)
271 if (cmd->start_arg != 0) {
275 if (cmd->scan_begin_arg != 0) {
276 cmd->scan_begin_arg = 0;
279 if (cmd->convert_arg != 0) {
280 cmd->convert_arg = 0;
283 if (cmd->scan_end_arg != 1) {
284 cmd->scan_end_arg = 1;
287 if (cmd->stop_arg != 0) {
303 static int subdev_8255_cmd(struct comedi_device *dev,
304 struct comedi_subdevice *s)
311 static int subdev_8255_cancel(struct comedi_device *dev,
312 struct comedi_subdevice *s)
319 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
320 int (*io) (int, int, int, unsigned long),
321 unsigned long iobase)
323 struct subdev_8255_private *spriv;
325 spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
329 spriv->iobase = iobase;
330 spriv->io = io ? io : subdev_8255_io;
334 s->type = COMEDI_SUBD_DIO;
335 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
337 s->range_table = &range_digital;
339 s->insn_bits = subdev_8255_insn;
340 s->insn_config = subdev_8255_insn_config;
345 subdev_8255_do_config(dev, s);
349 EXPORT_SYMBOL(subdev_8255_init);
351 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
352 int (*io) (int, int, int, unsigned long),
353 unsigned long iobase)
357 ret = subdev_8255_init(dev, s, io, iobase);
361 s->do_cmdtest = subdev_8255_cmdtest;
362 s->do_cmd = subdev_8255_cmd;
363 s->cancel = subdev_8255_cancel;
367 EXPORT_SYMBOL(subdev_8255_init_irq);
369 void subdev_8255_cleanup(struct comedi_device *dev, struct comedi_subdevice *s)
373 EXPORT_SYMBOL(subdev_8255_cleanup);
377 Start of the 8255 standalone device
381 static int dev_8255_attach(struct comedi_device *dev,
382 struct comedi_devconfig *it)
384 struct comedi_subdevice *s;
386 unsigned long iobase;
389 dev->board_name = "8255";
391 for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
392 iobase = it->options[i];
397 dev_warn(dev->class_dev, "no devices specified\n");
401 ret = comedi_alloc_subdevices(dev, i);
405 for (i = 0; i < dev->n_subdevices; i++) {
406 s = dev->subdevices + i;
407 iobase = it->options[i];
409 if (!request_region(iobase, _8255_SIZE, "8255")) {
410 dev_warn(dev->class_dev,
411 "0x%04lx (I/O port conflict)\n", iobase);
413 s->type = COMEDI_SUBD_UNUSED;
415 ret = subdev_8255_init(dev, s, NULL, iobase);
418 dev_info(dev->class_dev, "0x%04lx\n", iobase);
425 static void dev_8255_detach(struct comedi_device *dev)
427 struct comedi_subdevice *s;
428 struct subdev_8255_private *spriv;
431 for (i = 0; i < dev->n_subdevices; i++) {
432 s = dev->subdevices + i;
433 if (s->type != COMEDI_SUBD_UNUSED) {
435 release_region(spriv->iobase, _8255_SIZE);
437 subdev_8255_cleanup(dev, s);
441 static struct comedi_driver dev_8255_driver = {
442 .driver_name = "8255",
443 .module = THIS_MODULE,
444 .attach = dev_8255_attach,
445 .detach = dev_8255_detach,
447 module_comedi_driver(dev_8255_driver);
449 MODULE_AUTHOR("Comedi http://www.comedi.org");
450 MODULE_DESCRIPTION("Comedi low-level driver");
451 MODULE_LICENSE("GPL");