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, callback_function, arg)
65 device and subdevice are pointers to the device and subdevice
66 structures. callback_function will be called to provide the
67 low-level input/output to the device, i.e., actual register
68 access. callback_function will be called with the value of arg
69 as the last parameter. If the 8255 device is mapped as 4
70 consecutive I/O ports, you can use NULL for callback_function
71 and the I/O port base for arg, 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_struct {
101 unsigned long cb_arg;
102 int (*cb_func) (int, int, int, unsigned long);
106 #define CALLBACK_ARG (((struct subdev_8255_struct *)s->private)->cb_arg)
107 #define CALLBACK_FUNC (((struct subdev_8255_struct *)s->private)->cb_func)
108 #define subdevpriv ((struct subdev_8255_struct *)s->private)
110 static int dev_8255_attach(struct comedi_device *dev,
111 struct comedi_devconfig *it);
112 static int dev_8255_detach(struct comedi_device *dev);
113 static struct comedi_driver driver_8255 = {
114 .driver_name = "8255",
115 .module = THIS_MODULE,
116 .attach = dev_8255_attach,
117 .detach = dev_8255_detach,
120 COMEDI_INITCLEANUP(driver_8255);
122 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s);
124 void subdev_8255_interrupt(struct comedi_device *dev,
125 struct comedi_subdevice *s)
129 d = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
130 d |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
132 comedi_buf_put(s->async, d);
133 s->async->events |= COMEDI_CB_EOS;
135 comedi_event(dev, s);
137 EXPORT_SYMBOL(subdev_8255_interrupt);
139 static int subdev_8255_cb(int dir, int port, int data, unsigned long arg)
141 unsigned long iobase = arg;
144 outb(data, iobase + port);
147 return inb(iobase + port);
151 static int subdev_8255_insn(struct comedi_device *dev,
152 struct comedi_subdevice *s,
153 struct comedi_insn *insn, unsigned int *data)
156 s->state &= ~data[0];
157 s->state |= (data[0] & data[1]);
160 CALLBACK_FUNC(1, _8255_DATA, s->state & 0xff,
162 if (data[0] & 0xff00)
163 CALLBACK_FUNC(1, _8255_DATA + 1, (s->state >> 8) & 0xff,
165 if (data[0] & 0xff0000)
166 CALLBACK_FUNC(1, _8255_DATA + 2,
167 (s->state >> 16) & 0xff, CALLBACK_ARG);
170 data[1] = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
171 data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
172 data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 2, 0, CALLBACK_ARG) << 16);
177 static int subdev_8255_insn_config(struct comedi_device *dev,
178 struct comedi_subdevice *s,
179 struct comedi_insn *insn, unsigned int *data)
184 mask = 1 << CR_CHAN(insn->chanspec);
187 else if (mask & 0x00ff00)
189 else if (mask & 0x0f0000)
195 case INSN_CONFIG_DIO_INPUT:
198 case INSN_CONFIG_DIO_OUTPUT:
201 case INSN_CONFIG_DIO_QUERY:
202 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;
214 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s)
219 /* 1 in io_bits indicates output, 1 in config indicates input */
220 if (!(s->io_bits & 0x0000ff))
222 if (!(s->io_bits & 0x00ff00))
224 if (!(s->io_bits & 0x0f0000))
225 config |= CR_C_LO_IO;
226 if (!(s->io_bits & 0xf00000))
227 config |= CR_C_HI_IO;
228 CALLBACK_FUNC(1, _8255_CR, config, CALLBACK_ARG);
231 static int subdev_8255_cmdtest(struct comedi_device *dev,
232 struct comedi_subdevice *s,
233 struct comedi_cmd *cmd)
240 tmp = cmd->start_src;
241 cmd->start_src &= TRIG_NOW;
242 if (!cmd->start_src || tmp != cmd->start_src)
245 tmp = cmd->scan_begin_src;
246 cmd->scan_begin_src &= TRIG_EXT;
247 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
250 tmp = cmd->convert_src;
251 cmd->convert_src &= TRIG_FOLLOW;
252 if (!cmd->convert_src || tmp != cmd->convert_src)
255 tmp = cmd->scan_end_src;
256 cmd->scan_end_src &= TRIG_COUNT;
257 if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
261 cmd->stop_src &= TRIG_NONE;
262 if (!cmd->stop_src || tmp != cmd->stop_src)
275 if (cmd->start_arg != 0) {
279 if (cmd->scan_begin_arg != 0) {
280 cmd->scan_begin_arg = 0;
283 if (cmd->convert_arg != 0) {
284 cmd->convert_arg = 0;
287 if (cmd->scan_end_arg != 1) {
288 cmd->scan_end_arg = 1;
291 if (cmd->stop_arg != 0) {
307 static int subdev_8255_cmd(struct comedi_device *dev,
308 struct comedi_subdevice *s)
315 static int subdev_8255_cancel(struct comedi_device *dev,
316 struct comedi_subdevice *s)
323 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
324 int (*cb) (int, int, int, unsigned long),
327 s->type = COMEDI_SUBD_DIO;
328 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
330 s->range_table = &range_digital;
333 s->private = kmalloc(sizeof(struct subdev_8255_struct), GFP_KERNEL);
339 CALLBACK_FUNC = subdev_8255_cb;
342 s->insn_bits = subdev_8255_insn;
343 s->insn_config = subdev_8255_insn_config;
351 EXPORT_SYMBOL(subdev_8255_init);
353 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
354 int (*cb) (int, int, int, unsigned long),
359 ret = subdev_8255_init(dev, s, cb, arg);
363 s->do_cmdtest = subdev_8255_cmdtest;
364 s->do_cmd = subdev_8255_cmd;
365 s->cancel = subdev_8255_cancel;
367 subdevpriv->have_irq = 1;
371 EXPORT_SYMBOL(subdev_8255_init_irq);
373 void subdev_8255_cleanup(struct comedi_device *dev, struct comedi_subdevice *s)
376 /* this test does nothing, so comment it out
377 * if (subdevpriv->have_irq) {
384 EXPORT_SYMBOL(subdev_8255_cleanup);
388 Start of the 8255 standalone device
392 static int dev_8255_attach(struct comedi_device *dev,
393 struct comedi_devconfig *it)
396 unsigned long iobase;
399 dev->board_name = "8255";
401 for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
402 iobase = it->options[i];
408 "comedi%d: 8255: no devices specified\n", dev->minor);
412 ret = alloc_subdevices(dev, i);
414 /* FIXME this printk call should give a proper message, the
415 * below line just maintains previous functionality */
416 printk("comedi%d: 8255:", dev->minor);
420 printk(KERN_INFO "comedi%d: 8255:", dev->minor);
422 for (i = 0; i < dev->n_subdevices; i++) {
423 iobase = it->options[i];
425 printk(" 0x%04lx", iobase);
426 if (!request_region(iobase, _8255_SIZE, "8255")) {
427 printk(" (I/O port conflict)");
429 dev->subdevices[i].type = COMEDI_SUBD_UNUSED;
431 subdev_8255_init(dev, dev->subdevices + i, NULL,
441 static int dev_8255_detach(struct comedi_device *dev)
444 unsigned long iobase;
445 struct comedi_subdevice *s;
447 printk(KERN_INFO "comedi%d: 8255: remove\n", dev->minor);
449 for (i = 0; i < dev->n_subdevices; i++) {
450 s = dev->subdevices + i;
451 if (s->type != COMEDI_SUBD_UNUSED) {
452 iobase = CALLBACK_ARG;
453 release_region(iobase, _8255_SIZE);
455 subdev_8255_cleanup(dev, s);