1 /*
2 comedi/drivers/8255.c
3 Driver for 8255
4
5 COMEDI - Linux Control and Measurement Device Interface
6 Copyright (C) 1998 David A. Schleef <ds@schleef.org>
7
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.
12
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.
17
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.
21
22 */
23 /*
24 Driver: 8255
25 Description: generic 8255 support
26 Devices: [standard] 8255 (8255)
27 Author: ds
28 Status: works
29 Updated: Fri, 7 Jun 2002 12:56:45 -0700
30
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
36 supported is mode 0.
37
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.
41
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,
47
48 comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c
49
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'.
53
54 */
55
56 /*
57 This file contains an exported subdevice for driving an 8255.
58
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
61 calling:
62
63 subdev_8255_init(device, subdevice, callback_function, arg)
64
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.
73
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.
79 */
80
81 #include "../comedidev.h"
82
83 #include <linux/ioport.h>
84 #include <linux/slab.h>
85 #include "8255.h"
86
87 #define _8255_SIZE 4
88
89 #define _8255_DATA 0
90 #define _8255_CR 3
91
92 #define CR_C_LO_IO 0x01
93 #define CR_B_IO 0x02
94 #define CR_B_MODE 0x04
95 #define CR_C_HI_IO 0x08
96 #define CR_A_IO 0x10
97 #define CR_A_MODE(a) ((a)<<5)
98 #define CR_CW 0x80
99
100 struct subdev_8255_struct {
101 unsigned long cb_arg;
102 int (*cb_func) (int, int, int, unsigned long);
103 int have_irq;
104 };
105
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)
109
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,
118 };
119
driver_8255_init_module(void)120 static int __init driver_8255_init_module(void)
121 {
122 return comedi_driver_register(&driver_8255);
123 }
124
driver_8255_cleanup_module(void)125 static void __exit driver_8255_cleanup_module(void)
126 {
127 comedi_driver_unregister(&driver_8255);
128 }
129
130 module_init(driver_8255_init_module);
131 module_exit(driver_8255_cleanup_module);
132
133 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s);
134
subdev_8255_interrupt(struct comedi_device * dev,struct comedi_subdevice * s)135 void subdev_8255_interrupt(struct comedi_device *dev,
136 struct comedi_subdevice *s)
137 {
138 short d;
139
140 d = CALLBACK_FUNC(0, _8255_DATA, 0, CALLBACK_ARG);
141 d |= (CALLBACK_FUNC(0, _8255_DATA + 1, 0, CALLBACK_ARG) << 8);
142
143 comedi_buf_put(s->async, d);
144 s->async->events |= COMEDI_CB_EOS;
145
146 comedi_event(dev, s);
147 }
148 EXPORT_SYMBOL(subdev_8255_interrupt);
149
subdev_8255_cb(int dir,int port,int data,unsigned long arg)150 static int subdev_8255_cb(int dir, int port, int data, unsigned long arg)
151 {
152 unsigned long iobase = arg;
153
154 if (dir) {
155 outb(data, iobase + port);
156 return 0;
157 } else {
158 return inb(iobase + port);
159 }
160 }
161
subdev_8255_insn(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)162 static int subdev_8255_insn(struct comedi_device *dev,
163 struct comedi_subdevice *s,
164 struct comedi_insn *insn, unsigned int *data)
165 {
166 if (data[0]) {
167 s->state &= ~data[0];
168 s->state |= (data[0] & data[1]);
169
170 if (data[0] & 0xff)
171 CALLBACK_FUNC(1, _8255_DATA, s->state & 0xff,
172 CALLBACK_ARG);
173 if (data[0] & 0xff00)
174 CALLBACK_FUNC(1, _8255_DATA + 1, (s->state >> 8) & 0xff,
175 CALLBACK_ARG);
176 if (data[0] & 0xff0000)
177 CALLBACK_FUNC(1, _8255_DATA + 2,
178 (s->state >> 16) & 0xff, CALLBACK_ARG);
179 }
180
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);
184
185 return 2;
186 }
187
subdev_8255_insn_config(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)188 static int subdev_8255_insn_config(struct comedi_device *dev,
189 struct comedi_subdevice *s,
190 struct comedi_insn *insn, unsigned int *data)
191 {
192 unsigned int mask;
193 unsigned int bits;
194
195 mask = 1 << CR_CHAN(insn->chanspec);
196 if (mask & 0x0000ff)
197 bits = 0x0000ff;
198 else if (mask & 0x00ff00)
199 bits = 0x00ff00;
200 else if (mask & 0x0f0000)
201 bits = 0x0f0000;
202 else
203 bits = 0xf00000;
204
205 switch (data[0]) {
206 case INSN_CONFIG_DIO_INPUT:
207 s->io_bits &= ~bits;
208 break;
209 case INSN_CONFIG_DIO_OUTPUT:
210 s->io_bits |= bits;
211 break;
212 case INSN_CONFIG_DIO_QUERY:
213 data[1] = (s->io_bits & bits) ? COMEDI_OUTPUT : COMEDI_INPUT;
214 return insn->n;
215 break;
216 default:
217 return -EINVAL;
218 }
219
220 do_config(dev, s);
221
222 return 1;
223 }
224
do_config(struct comedi_device * dev,struct comedi_subdevice * s)225 static void do_config(struct comedi_device *dev, struct comedi_subdevice *s)
226 {
227 int config;
228
229 config = CR_CW;
230 /* 1 in io_bits indicates output, 1 in config indicates input */
231 if (!(s->io_bits & 0x0000ff))
232 config |= CR_A_IO;
233 if (!(s->io_bits & 0x00ff00))
234 config |= CR_B_IO;
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);
240 }
241
subdev_8255_cmdtest(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_cmd * cmd)242 static int subdev_8255_cmdtest(struct comedi_device *dev,
243 struct comedi_subdevice *s,
244 struct comedi_cmd *cmd)
245 {
246 int err = 0;
247 unsigned int tmp;
248
249 /* step 1 */
250
251 tmp = cmd->start_src;
252 cmd->start_src &= TRIG_NOW;
253 if (!cmd->start_src || tmp != cmd->start_src)
254 err++;
255
256 tmp = cmd->scan_begin_src;
257 cmd->scan_begin_src &= TRIG_EXT;
258 if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
259 err++;
260
261 tmp = cmd->convert_src;
262 cmd->convert_src &= TRIG_FOLLOW;
263 if (!cmd->convert_src || tmp != cmd->convert_src)
264 err++;
265
266 tmp = cmd->scan_end_src;
267 cmd->scan_end_src &= TRIG_COUNT;
268 if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
269 err++;
270
271 tmp = cmd->stop_src;
272 cmd->stop_src &= TRIG_NONE;
273 if (!cmd->stop_src || tmp != cmd->stop_src)
274 err++;
275
276 if (err)
277 return 1;
278
279 /* step 2 */
280
281 if (err)
282 return 2;
283
284 /* step 3 */
285
286 if (cmd->start_arg != 0) {
287 cmd->start_arg = 0;
288 err++;
289 }
290 if (cmd->scan_begin_arg != 0) {
291 cmd->scan_begin_arg = 0;
292 err++;
293 }
294 if (cmd->convert_arg != 0) {
295 cmd->convert_arg = 0;
296 err++;
297 }
298 if (cmd->scan_end_arg != 1) {
299 cmd->scan_end_arg = 1;
300 err++;
301 }
302 if (cmd->stop_arg != 0) {
303 cmd->stop_arg = 0;
304 err++;
305 }
306
307 if (err)
308 return 3;
309
310 /* step 4 */
311
312 if (err)
313 return 4;
314
315 return 0;
316 }
317
subdev_8255_cmd(struct comedi_device * dev,struct comedi_subdevice * s)318 static int subdev_8255_cmd(struct comedi_device *dev,
319 struct comedi_subdevice *s)
320 {
321 /* FIXME */
322
323 return 0;
324 }
325
subdev_8255_cancel(struct comedi_device * dev,struct comedi_subdevice * s)326 static int subdev_8255_cancel(struct comedi_device *dev,
327 struct comedi_subdevice *s)
328 {
329 /* FIXME */
330
331 return 0;
332 }
333
subdev_8255_init(struct comedi_device * dev,struct comedi_subdevice * s,int (* cb)(int,int,int,unsigned long),unsigned long arg)334 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
335 int (*cb) (int, int, int, unsigned long),
336 unsigned long arg)
337 {
338 s->type = COMEDI_SUBD_DIO;
339 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
340 s->n_chan = 24;
341 s->range_table = &range_digital;
342 s->maxdata = 1;
343
344 s->private = kmalloc(sizeof(struct subdev_8255_struct), GFP_KERNEL);
345 if (!s->private)
346 return -ENOMEM;
347
348 CALLBACK_ARG = arg;
349 if (cb == NULL)
350 CALLBACK_FUNC = subdev_8255_cb;
351 else
352 CALLBACK_FUNC = cb;
353 s->insn_bits = subdev_8255_insn;
354 s->insn_config = subdev_8255_insn_config;
355
356 s->state = 0;
357 s->io_bits = 0;
358 do_config(dev, s);
359
360 return 0;
361 }
362 EXPORT_SYMBOL(subdev_8255_init);
363
subdev_8255_init_irq(struct comedi_device * dev,struct comedi_subdevice * s,int (* cb)(int,int,int,unsigned long),unsigned long arg)364 int subdev_8255_init_irq(struct comedi_device *dev, struct comedi_subdevice *s,
365 int (*cb) (int, int, int, unsigned long),
366 unsigned long arg)
367 {
368 int ret;
369
370 ret = subdev_8255_init(dev, s, cb, arg);
371 if (ret < 0)
372 return ret;
373
374 s->do_cmdtest = subdev_8255_cmdtest;
375 s->do_cmd = subdev_8255_cmd;
376 s->cancel = subdev_8255_cancel;
377
378 subdevpriv->have_irq = 1;
379
380 return 0;
381 }
382 EXPORT_SYMBOL(subdev_8255_init_irq);
383
subdev_8255_cleanup(struct comedi_device * dev,struct comedi_subdevice * s)384 void subdev_8255_cleanup(struct comedi_device *dev, struct comedi_subdevice *s)
385 {
386 kfree(s->private);
387 }
388 EXPORT_SYMBOL(subdev_8255_cleanup);
389
390 /*
391
392 Start of the 8255 standalone device
393
394 */
395
dev_8255_attach(struct comedi_device * dev,struct comedi_devconfig * it)396 static int dev_8255_attach(struct comedi_device *dev,
397 struct comedi_devconfig *it)
398 {
399 int ret;
400 unsigned long iobase;
401 int i;
402
403 dev->board_name = "8255";
404
405 for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
406 iobase = it->options[i];
407 if (!iobase)
408 break;
409 }
410 if (i == 0) {
411 printk(KERN_WARNING
412 "comedi%d: 8255: no devices specified\n", dev->minor);
413 return -EINVAL;
414 }
415
416 ret = alloc_subdevices(dev, i);
417 if (ret < 0) {
418 /* FIXME this printk call should give a proper message, the
419 * below line just maintains previous functionality */
420 printk("comedi%d: 8255:", dev->minor);
421 return ret;
422 }
423
424 printk(KERN_INFO "comedi%d: 8255:", dev->minor);
425
426 for (i = 0; i < dev->n_subdevices; i++) {
427 iobase = it->options[i];
428
429 printk(" 0x%04lx", iobase);
430 if (!request_region(iobase, _8255_SIZE, "8255")) {
431 printk(" (I/O port conflict)");
432
433 dev->subdevices[i].type = COMEDI_SUBD_UNUSED;
434 } else {
435 subdev_8255_init(dev, dev->subdevices + i, NULL,
436 iobase);
437 }
438 }
439
440 printk("\n");
441
442 return 0;
443 }
444
dev_8255_detach(struct comedi_device * dev)445 static int dev_8255_detach(struct comedi_device *dev)
446 {
447 int i;
448 unsigned long iobase;
449 struct comedi_subdevice *s;
450
451 printk(KERN_INFO "comedi%d: 8255: remove\n", dev->minor);
452
453 for (i = 0; i < dev->n_subdevices; i++) {
454 s = dev->subdevices + i;
455 if (s->type != COMEDI_SUBD_UNUSED) {
456 iobase = CALLBACK_ARG;
457 release_region(iobase, _8255_SIZE);
458 }
459 subdev_8255_cleanup(dev, s);
460 }
461
462 return 0;
463 }
464
465 MODULE_AUTHOR("Comedi http://www.comedi.org");
466 MODULE_DESCRIPTION("Comedi low-level driver");
467 MODULE_LICENSE("GPL");
468