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>
90 #define CR_C_LO_IO 0x01
92 #define CR_B_MODE 0x04
93 #define CR_C_HI_IO 0x08
95 #define CR_A_MODE(a) ((a)<<5)
98 struct subdev_8255_struct {
100 int (*cb_func) (int, int, int, unsigned long);
104 #define CALLBACK_ARG (((struct subdev_8255_struct *)s->private)->cb_arg)
105 #define CALLBACK_FUNC (((struct subdev_8255_struct *)s->private)->cb_func)
106 #define subdevpriv ((struct subdev_8255_struct *)s->private)
108 static int dev_8255_attach(struct comedi_device *dev,
109 struct comedi_devconfig *it);
110 static int dev_8255_detach(struct comedi_device *dev);
111 static struct comedi_driver driver_8255 = {
112 .driver_name = "8255",
113 .module = THIS_MODULE,
114 .attach = dev_8255_attach,
115 .detach = dev_8255_detach,
118 COMEDI_INITCLEANUP(driver_8255);
120 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s);
122 void subdev_8255_interrupt(struct comedi_device *dev,
123 struct comedi_subdevice *s)
127 d = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
128 d |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
130 comedi_buf_put(s->async, d);
131 s->async->events |= COMEDI_CB_EOS;
133 comedi_event(dev, s);
136 static int subdev_8255_cb(int dir, int port, int data, unsigned long arg)
138 unsigned long iobase = arg;
141 outb(data, iobase + port);
144 return inb(iobase + port);
148 static int subdev_8255_insn(struct comedi_device *dev,
149 struct comedi_subdevice *s,
150 struct comedi_insn *insn, unsigned int *data)
153 s->state &= ~data[0];
154 s->state |= (data[0] & data[1]);
157 CALLBACK_FUNC(1, _8255_DATA, s->state & 0xff,
159 if (data[0] & 0xff00)
160 CALLBACK_FUNC(1, _8255_DATA + 1, (s->state >> 8) & 0xff,
162 if (data[0] & 0xff0000)
163 CALLBACK_FUNC(1, _8255_DATA + 2,
164 (s->state >> 16) & 0xff, CALLBACK_ARG);
167 data[1] = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
168 data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
169 data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 2, 0, CALLBACK_ARG) << 16);
174 static int subdev_8255_insn_config(struct comedi_device *dev,
175 struct comedi_subdevice *s,
176 struct comedi_insn *insn, unsigned int *data)
181 mask = 1 << CR_CHAN(insn->chanspec);
182 if (mask & 0x0000ff) {
184 } else if (mask & 0x00ff00) {
186 } else if (mask & 0x0f0000) {
193 case INSN_CONFIG_DIO_INPUT:
196 case INSN_CONFIG_DIO_OUTPUT:
199 case INSN_CONFIG_DIO_QUERY:
200 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;
212 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s)
217 /* 1 in io_bits indicates output, 1 in config indicates input */
218 if (!(s->io_bits & 0x0000ff))
220 if (!(s->io_bits & 0x00ff00))
222 if (!(s->io_bits & 0x0f0000))
223 config |= CR_C_LO_IO;
224 if (!(s->io_bits & 0xf00000))
225 config |= CR_C_HI_IO;
226 CALLBACK_FUNC(1, _8255_CR, config, CALLBACK_ARG);
229 static int subdev_8255_cmdtest(struct comedi_device *dev,
230 struct comedi_subdevice *s,
231 struct comedi_cmd *cmd)
238 tmp = cmd->start_src;
239 cmd->start_src &= TRIG_NOW;
240 if (!cmd->start_src || tmp != cmd->start_src)
243 tmp = cmd->scan_begin_src;
244 cmd->scan_begin_src &= TRIG_EXT;
245 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
248 tmp = cmd->convert_src;
249 cmd->convert_src &= TRIG_FOLLOW;
250 if (!cmd->convert_src || tmp != cmd->convert_src)
253 tmp = cmd->scan_end_src;
254 cmd->scan_end_src &= TRIG_COUNT;
255 if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
259 cmd->stop_src &= TRIG_NONE;
260 if (!cmd->stop_src || tmp != cmd->stop_src)
273 if (cmd->start_arg != 0) {
277 if (cmd->scan_begin_arg != 0) {
278 cmd->scan_begin_arg = 0;
281 if (cmd->convert_arg != 0) {
282 cmd->convert_arg = 0;
285 if (cmd->scan_end_arg != 1) {
286 cmd->scan_end_arg = 1;
289 if (cmd->stop_arg != 0) {
305 static int subdev_8255_cmd(struct comedi_device *dev,
306 struct comedi_subdevice *s)
313 static int subdev_8255_cancel(struct comedi_device *dev,
314 struct comedi_subdevice *s)
321 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
322 int (*cb) (int, int, int, unsigned long),
325 s->type = COMEDI_SUBD_DIO;
326 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
328 s->range_table = &range_digital;
331 s->private = kmalloc(sizeof(struct subdev_8255_struct), GFP_KERNEL);
337 CALLBACK_FUNC = subdev_8255_cb;
341 s->insn_bits = subdev_8255_insn;
342 s->insn_config = subdev_8255_insn_config;
351 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
352 int (*cb) (int, int, int, unsigned long),
357 ret = subdev_8255_init(dev, s, cb, arg);
361 s->do_cmdtest = subdev_8255_cmdtest;
362 s->do_cmd = subdev_8255_cmd;
363 s->cancel = subdev_8255_cancel;
365 subdevpriv->have_irq = 1;
370 void subdev_8255_cleanup(struct comedi_device *dev, struct comedi_subdevice *s)
373 /* this test does nothing, so comment it out
374 * if (subdevpriv->have_irq) {
384 Start of the 8255 standalone device
388 static int dev_8255_attach(struct comedi_device *dev,
389 struct comedi_devconfig *it)
392 unsigned long iobase;
395 printk("comedi%d: 8255:", dev->minor);
397 dev->board_name = "8255";
399 for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
400 iobase = it->options[i];
405 printk(" no devices specified\n");
409 ret = alloc_subdevices(dev, i);
413 for (i = 0; i < dev->n_subdevices; i++) {
414 iobase = it->options[i];
416 printk(" 0x%04lx", iobase);
417 if (!request_region(iobase, _8255_SIZE, "8255")) {
418 printk(" (I/O port conflict)");
420 dev->subdevices[i].type = COMEDI_SUBD_UNUSED;
422 subdev_8255_init(dev, dev->subdevices + i, NULL,
432 static int dev_8255_detach(struct comedi_device *dev)
435 unsigned long iobase;
436 struct comedi_subdevice *s;
438 printk("comedi%d: 8255: remove\n", dev->minor);
440 for (i = 0; i < dev->n_subdevices; i++) {
441 s = dev->subdevices + i;
442 if (s->type != COMEDI_SUBD_UNUSED) {
443 iobase = CALLBACK_ARG;
444 release_region(iobase, _8255_SIZE);
446 subdev_8255_cleanup(dev, s);
452 EXPORT_SYMBOL(subdev_8255_init);
453 EXPORT_SYMBOL(subdev_8255_init_irq);
454 EXPORT_SYMBOL(subdev_8255_cleanup);
455 EXPORT_SYMBOL(subdev_8255_interrupt);