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 static int __init driver_8255_init_module(void)
122 return comedi_driver_register(&driver_8255);
125 static void __exit driver_8255_cleanup_module(void)
127 comedi_driver_unregister(&driver_8255);
130 module_init(driver_8255_init_module);
131 module_exit(driver_8255_cleanup_module);
133 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s);
135 void subdev_8255_interrupt(struct comedi_device *dev,
136 struct comedi_subdevice *s)
140 d = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
141 d |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
143 comedi_buf_put(s->async, d);
144 s->async->events |= COMEDI_CB_EOS;
146 comedi_event(dev, s);
148 EXPORT_SYMBOL(subdev_8255_interrupt);
150 static int subdev_8255_cb(int dir, int port, int data, unsigned long arg)
152 unsigned long iobase = arg;
155 outb(data, iobase + port);
158 return inb(iobase + port);
162 static int subdev_8255_insn(struct comedi_device *dev,
163 struct comedi_subdevice *s,
164 struct comedi_insn *insn, unsigned int *data)
167 s->state &= ~data[0];
168 s->state |= (data[0] & data[1]);
171 CALLBACK_FUNC(1, _8255_DATA, s->state & 0xff,
173 if (data[0] & 0xff00)
174 CALLBACK_FUNC(1, _8255_DATA + 1, (s->state >> 8) & 0xff,
176 if (data[0] & 0xff0000)
177 CALLBACK_FUNC(1, _8255_DATA + 2,
178 (s->state >> 16) & 0xff, CALLBACK_ARG);
181 data[1] = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
182 data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
183 data[1] |= (CALLBACK_FUNC(0, _8255_DATA + 2, 0, CALLBACK_ARG) << 16);
188 static int subdev_8255_insn_config(struct comedi_device *dev,
189 struct comedi_subdevice *s,
190 struct comedi_insn *insn, unsigned int *data)
195 mask = 1 << CR_CHAN(insn->chanspec);
198 else if (mask & 0x00ff00)
200 else if (mask & 0x0f0000)
206 case INSN_CONFIG_DIO_INPUT:
209 case INSN_CONFIG_DIO_OUTPUT:
212 case INSN_CONFIG_DIO_QUERY:
213 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;
225 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s)
230 /* 1 in io_bits indicates output, 1 in config indicates input */
231 if (!(s->io_bits & 0x0000ff))
233 if (!(s->io_bits & 0x00ff00))
235 if (!(s->io_bits & 0x0f0000))
236 config |= CR_C_LO_IO;
237 if (!(s->io_bits & 0xf00000))
238 config |= CR_C_HI_IO;
239 CALLBACK_FUNC(1, _8255_CR, config, CALLBACK_ARG);
242 static int subdev_8255_cmdtest(struct comedi_device *dev,
243 struct comedi_subdevice *s,
244 struct comedi_cmd *cmd)
251 tmp = cmd->start_src;
252 cmd->start_src &= TRIG_NOW;
253 if (!cmd->start_src || tmp != cmd->start_src)
256 tmp = cmd->scan_begin_src;
257 cmd->scan_begin_src &= TRIG_EXT;
258 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
261 tmp = cmd->convert_src;
262 cmd->convert_src &= TRIG_FOLLOW;
263 if (!cmd->convert_src || tmp != cmd->convert_src)
266 tmp = cmd->scan_end_src;
267 cmd->scan_end_src &= TRIG_COUNT;
268 if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
272 cmd->stop_src &= TRIG_NONE;
273 if (!cmd->stop_src || tmp != cmd->stop_src)
286 if (cmd->start_arg != 0) {
290 if (cmd->scan_begin_arg != 0) {
291 cmd->scan_begin_arg = 0;
294 if (cmd->convert_arg != 0) {
295 cmd->convert_arg = 0;
298 if (cmd->scan_end_arg != 1) {
299 cmd->scan_end_arg = 1;
302 if (cmd->stop_arg != 0) {
318 static int subdev_8255_cmd(struct comedi_device *dev,
319 struct comedi_subdevice *s)
326 static int subdev_8255_cancel(struct comedi_device *dev,
327 struct comedi_subdevice *s)
334 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
335 int (*cb) (int, int, int, unsigned long),
338 s->type = COMEDI_SUBD_DIO;
339 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
341 s->range_table = &range_digital;
344 s->private = kmalloc(sizeof(struct subdev_8255_struct), GFP_KERNEL);
350 CALLBACK_FUNC = subdev_8255_cb;
353 s->insn_bits = subdev_8255_insn;
354 s->insn_config = subdev_8255_insn_config;
362 EXPORT_SYMBOL(subdev_8255_init);
364 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
365 int (*cb) (int, int, int, unsigned long),
370 ret = subdev_8255_init(dev, s, cb, arg);
374 s->do_cmdtest = subdev_8255_cmdtest;
375 s->do_cmd = subdev_8255_cmd;
376 s->cancel = subdev_8255_cancel;
378 subdevpriv->have_irq = 1;
382 EXPORT_SYMBOL(subdev_8255_init_irq);
384 void subdev_8255_cleanup(struct comedi_device *dev, struct comedi_subdevice *s)
387 /* this test does nothing, so comment it out
388 * if (subdevpriv->have_irq) {
395 EXPORT_SYMBOL(subdev_8255_cleanup);
399 Start of the 8255 standalone device
403 static int dev_8255_attach(struct comedi_device *dev,
404 struct comedi_devconfig *it)
407 unsigned long iobase;
410 dev->board_name = "8255";
412 for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
413 iobase = it->options[i];
419 "comedi%d: 8255: no devices specified\n", dev->minor);
423 ret = alloc_subdevices(dev, i);
425 /* FIXME this printk call should give a proper message, the
426 * below line just maintains previous functionality */
427 printk("comedi%d: 8255:", dev->minor);
431 printk(KERN_INFO "comedi%d: 8255:", dev->minor);
433 for (i = 0; i < dev->n_subdevices; i++) {
434 iobase = it->options[i];
436 printk(" 0x%04lx", iobase);
437 if (!request_region(iobase, _8255_SIZE, "8255")) {
438 printk(" (I/O port conflict)");
440 dev->subdevices[i].type = COMEDI_SUBD_UNUSED;
442 subdev_8255_init(dev, dev->subdevices + i, NULL,
452 static int dev_8255_detach(struct comedi_device *dev)
455 unsigned long iobase;
456 struct comedi_subdevice *s;
458 printk(KERN_INFO "comedi%d: 8255: remove\n", dev->minor);
460 for (i = 0; i < dev->n_subdevices; i++) {
461 s = dev->subdevices + i;
462 if (s->type != COMEDI_SUBD_UNUSED) {
463 iobase = CALLBACK_ARG;
464 release_region(iobase, _8255_SIZE);
466 subdev_8255_cleanup(dev, s);
472 MODULE_AUTHOR("Comedi http://www.comedi.org");
473 MODULE_DESCRIPTION("Comedi low-level driver");
474 MODULE_LICENSE("GPL");