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.
20 Description: generic 8255 support
21 Devices: [standard] 8255 (8255)
24 Updated: Fri, 7 Jun 2002 12:56:45 -0700
26 The classic in digital I/O. The 8255 appears in Comedi as a single
27 digital I/O subdevice with 24 channels. The channel 0 corresponds
28 to the 8255's port A, bit 0; channel 23 corresponds to port C, bit
29 7. Direction configuration is done in blocks, with channels 0-7,
30 8-15, 16-19, and 20-23 making up the 4 blocks. The only 8255 mode
33 You should enable compilation this driver if you plan to use a board
34 that has an 8255 chip. For multifunction boards, the main driver will
35 configure the 8255 subdevice automatically.
37 This driver also works independently with ISA and PCI cards that
38 directly map the 8255 registers to I/O ports, including cards with
39 multiple 8255 chips. To configure the driver for such a card, the
40 option list should be a list of the I/O port bases for each of the
41 8255 chips. For example,
43 comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c
45 Note that most PCI 8255 boards do NOT work with this driver, and
46 need a separate driver as a wrapper. For those that do work, the
47 I/O port base address can be found in the output of 'lspci -v'.
52 This file contains an exported subdevice for driving an 8255.
54 To use this subdevice as part of another driver, you need to
55 set up the subdevice in the attach function of the driver by
58 subdev_8255_init(device, subdevice, io_function, iobase)
60 device and subdevice are pointers to the device and subdevice
61 structures. io_function will be called to provide the
62 low-level input/output to the device, i.e., actual register
63 access. io_function will be called with the value of iobase
64 as the last parameter. If the 8255 device is mapped as 4
65 consecutive I/O ports, you can use NULL for io_function
66 and the I/O port base for iobase, and an internal function will
67 handle the register access.
69 In addition, if the main driver handles interrupts, you can
70 enable commands on the subdevice by calling subdev_8255_init_irq()
71 instead. Then, when you get an interrupt that is likely to be
72 from the 8255, you should call subdev_8255_interrupt(), which
73 will copy the latched value to a Comedi buffer.
76 #include <linux/module.h>
77 #include "../comedidev.h"
79 #include <linux/ioport.h>
81 #include "comedi_fc.h"
89 #define CR_C_LO_IO 0x01
91 #define CR_B_MODE 0x04
92 #define CR_C_HI_IO 0x08
94 #define CR_A_MODE(a) ((a)<<5)
97 struct subdev_8255_private {
99 int (*io) (int, int, int, unsigned long);
102 static int subdev_8255_io(int dir, int port, int data, unsigned long iobase)
105 outb(data, iobase + port);
108 return inb(iobase + port);
112 void subdev_8255_interrupt(struct comedi_device *dev,
113 struct comedi_subdevice *s)
115 struct subdev_8255_private *spriv = s->private;
116 unsigned long iobase = spriv->iobase;
119 d = spriv->io(0, _8255_DATA, 0, iobase);
120 d |= (spriv->io(0, _8255_DATA + 1, 0, iobase) << 8);
122 comedi_buf_put(s->async, d);
123 s->async->events |= COMEDI_CB_EOS;
125 comedi_event(dev, s);
127 EXPORT_SYMBOL_GPL(subdev_8255_interrupt);
129 static int subdev_8255_insn(struct comedi_device *dev,
130 struct comedi_subdevice *s,
131 struct comedi_insn *insn, unsigned int *data)
133 struct subdev_8255_private *spriv = s->private;
134 unsigned long iobase = spriv->iobase;
148 spriv->io(1, _8255_DATA, v & 0xff, iobase);
150 spriv->io(1, _8255_DATA + 1, (v >> 8) & 0xff, iobase);
152 spriv->io(1, _8255_DATA + 2, (v >> 16) & 0xff, iobase);
157 v = spriv->io(0, _8255_DATA, 0, iobase);
158 v |= (spriv->io(0, _8255_DATA + 1, 0, iobase) << 8);
159 v |= (spriv->io(0, _8255_DATA + 2, 0, iobase) << 16);
166 static void subdev_8255_do_config(struct comedi_device *dev,
167 struct comedi_subdevice *s)
169 struct subdev_8255_private *spriv = s->private;
170 unsigned long iobase = spriv->iobase;
174 /* 1 in io_bits indicates output, 1 in config indicates input */
175 if (!(s->io_bits & 0x0000ff))
177 if (!(s->io_bits & 0x00ff00))
179 if (!(s->io_bits & 0x0f0000))
180 config |= CR_C_LO_IO;
181 if (!(s->io_bits & 0xf00000))
182 config |= CR_C_HI_IO;
184 spriv->io(1, _8255_CR, config, iobase);
187 static int subdev_8255_insn_config(struct comedi_device *dev,
188 struct comedi_subdevice *s,
189 struct comedi_insn *insn, unsigned int *data)
194 mask = 1 << CR_CHAN(insn->chanspec);
197 else if (mask & 0x00ff00)
199 else if (mask & 0x0f0000)
205 case INSN_CONFIG_DIO_INPUT:
208 case INSN_CONFIG_DIO_OUTPUT:
211 case INSN_CONFIG_DIO_QUERY:
212 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;
219 subdev_8255_do_config(dev, s);
224 static int subdev_8255_cmdtest(struct comedi_device *dev,
225 struct comedi_subdevice *s,
226 struct comedi_cmd *cmd)
230 /* Step 1 : check if triggers are trivially valid */
232 err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW);
233 err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
234 err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_FOLLOW);
235 err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
236 err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_NONE);
241 /* Step 2a : make sure trigger sources are unique */
242 /* Step 2b : and mutually compatible */
247 /* Step 3: check if arguments are trivially valid */
249 err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);
250 err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);
251 err |= cfc_check_trigger_arg_is(&cmd->convert_arg, 0);
252 err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, 1);
253 err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
266 static int subdev_8255_cmd(struct comedi_device *dev,
267 struct comedi_subdevice *s)
274 static int subdev_8255_cancel(struct comedi_device *dev,
275 struct comedi_subdevice *s)
282 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
283 int (*io) (int, int, int, unsigned long),
284 unsigned long iobase)
286 struct subdev_8255_private *spriv;
288 spriv = comedi_alloc_spriv(s, sizeof(*spriv));
292 spriv->iobase = iobase;
293 spriv->io = io ? io : subdev_8255_io;
295 s->type = COMEDI_SUBD_DIO;
296 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
298 s->range_table = &range_digital;
300 s->insn_bits = subdev_8255_insn;
301 s->insn_config = subdev_8255_insn_config;
306 subdev_8255_do_config(dev, s);
310 EXPORT_SYMBOL_GPL(subdev_8255_init);
312 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
313 int (*io) (int, int, int, unsigned long),
314 unsigned long iobase)
318 ret = subdev_8255_init(dev, s, io, iobase);
322 s->do_cmdtest = subdev_8255_cmdtest;
323 s->do_cmd = subdev_8255_cmd;
324 s->cancel = subdev_8255_cancel;
328 EXPORT_SYMBOL_GPL(subdev_8255_init_irq);
332 Start of the 8255 standalone device
336 static int dev_8255_attach(struct comedi_device *dev,
337 struct comedi_devconfig *it)
339 struct comedi_subdevice *s;
341 unsigned long iobase;
344 for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
345 iobase = it->options[i];
350 dev_warn(dev->class_dev, "no devices specified\n");
354 ret = comedi_alloc_subdevices(dev, i);
358 for (i = 0; i < dev->n_subdevices; i++) {
359 s = &dev->subdevices[i];
360 iobase = it->options[i];
362 ret = __comedi_request_region(dev, iobase, _8255_SIZE);
364 s->type = COMEDI_SUBD_UNUSED;
366 ret = subdev_8255_init(dev, s, NULL, iobase);
375 static void dev_8255_detach(struct comedi_device *dev)
377 struct comedi_subdevice *s;
378 struct subdev_8255_private *spriv;
381 for (i = 0; i < dev->n_subdevices; i++) {
382 s = &dev->subdevices[i];
383 if (s->type != COMEDI_SUBD_UNUSED) {
385 release_region(spriv->iobase, _8255_SIZE);
390 static struct comedi_driver dev_8255_driver = {
391 .driver_name = "8255",
392 .module = THIS_MODULE,
393 .attach = dev_8255_attach,
394 .detach = dev_8255_detach,
396 module_comedi_driver(dev_8255_driver);
398 MODULE_AUTHOR("Comedi http://www.comedi.org");
399 MODULE_DESCRIPTION("Comedi low-level driver");
400 MODULE_LICENSE("GPL");