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
19 /*
20 * Driver: 8255
21 * Description: generic 8255 support
22 * Devices: [standard] 8255 (8255)
23 * Author: ds
24 * Status: works
25 * Updated: Fri, 7 Jun 2002 12:56:45 -0700
26 *
27 * The classic in digital I/O. The 8255 appears in Comedi as a single
28 * digital I/O subdevice with 24 channels. The channel 0 corresponds
29 * to the 8255's port A, bit 0; channel 23 corresponds to port C, bit
30 * 7. Direction configuration is done in blocks, with channels 0-7,
31 * 8-15, 16-19, and 20-23 making up the 4 blocks. The only 8255 mode
32 * supported is mode 0.
33 *
34 * You should enable compilation this driver if you plan to use a board
35 * that has an 8255 chip. For multifunction boards, the main driver will
36 * configure the 8255 subdevice automatically.
37 *
38 * This driver also works independently with ISA and PCI cards that
39 * directly map the 8255 registers to I/O ports, including cards with
40 * multiple 8255 chips. To configure the driver for such a card, the
41 * option list should be a list of the I/O port bases for each of the
42 * 8255 chips. For example,
43 *
44 * comedi_config /dev/comedi0 8255 0x200,0x204,0x208,0x20c
45 *
46 * Note that most PCI 8255 boards do NOT work with this driver, and
47 * need a separate driver as a wrapper. For those that do work, the
48 * I/O port base address can be found in the output of 'lspci -v'.
49 */
50
51 #include <linux/module.h>
52 #include "../comedidev.h"
53
54 #include "8255.h"
55
56 struct subdev_8255_private {
57 unsigned long regbase;
58 int (*io)(struct comedi_device *, int, int, int, unsigned long);
59 };
60
subdev_8255_io(struct comedi_device * dev,int dir,int port,int data,unsigned long regbase)61 static int subdev_8255_io(struct comedi_device *dev,
62 int dir, int port, int data, unsigned long regbase)
63 {
64 if (dir) {
65 outb(data, dev->iobase + regbase + port);
66 return 0;
67 }
68 return inb(dev->iobase + regbase + port);
69 }
70
subdev_8255_mmio(struct comedi_device * dev,int dir,int port,int data,unsigned long regbase)71 static int subdev_8255_mmio(struct comedi_device *dev,
72 int dir, int port, int data, unsigned long regbase)
73 {
74 if (dir) {
75 writeb(data, dev->mmio + regbase + port);
76 return 0;
77 }
78 return readb(dev->mmio + regbase + port);
79 }
80
subdev_8255_insn(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)81 static int subdev_8255_insn(struct comedi_device *dev,
82 struct comedi_subdevice *s,
83 struct comedi_insn *insn,
84 unsigned int *data)
85 {
86 struct subdev_8255_private *spriv = s->private;
87 unsigned long regbase = spriv->regbase;
88 unsigned int mask;
89 unsigned int v;
90
91 mask = comedi_dio_update_state(s, data);
92 if (mask) {
93 if (mask & 0xff)
94 spriv->io(dev, 1, I8255_DATA_A_REG,
95 s->state & 0xff, regbase);
96 if (mask & 0xff00)
97 spriv->io(dev, 1, I8255_DATA_B_REG,
98 (s->state >> 8) & 0xff, regbase);
99 if (mask & 0xff0000)
100 spriv->io(dev, 1, I8255_DATA_C_REG,
101 (s->state >> 16) & 0xff, regbase);
102 }
103
104 v = spriv->io(dev, 0, I8255_DATA_A_REG, 0, regbase);
105 v |= (spriv->io(dev, 0, I8255_DATA_B_REG, 0, regbase) << 8);
106 v |= (spriv->io(dev, 0, I8255_DATA_C_REG, 0, regbase) << 16);
107
108 data[1] = v;
109
110 return insn->n;
111 }
112
subdev_8255_do_config(struct comedi_device * dev,struct comedi_subdevice * s)113 static void subdev_8255_do_config(struct comedi_device *dev,
114 struct comedi_subdevice *s)
115 {
116 struct subdev_8255_private *spriv = s->private;
117 unsigned long regbase = spriv->regbase;
118 int config;
119
120 config = I8255_CTRL_CW;
121 /* 1 in io_bits indicates output, 1 in config indicates input */
122 if (!(s->io_bits & 0x0000ff))
123 config |= I8255_CTRL_A_IO;
124 if (!(s->io_bits & 0x00ff00))
125 config |= I8255_CTRL_B_IO;
126 if (!(s->io_bits & 0x0f0000))
127 config |= I8255_CTRL_C_LO_IO;
128 if (!(s->io_bits & 0xf00000))
129 config |= I8255_CTRL_C_HI_IO;
130
131 spriv->io(dev, 1, I8255_CTRL_REG, config, regbase);
132 }
133
subdev_8255_insn_config(struct comedi_device * dev,struct comedi_subdevice * s,struct comedi_insn * insn,unsigned int * data)134 static int subdev_8255_insn_config(struct comedi_device *dev,
135 struct comedi_subdevice *s,
136 struct comedi_insn *insn,
137 unsigned int *data)
138 {
139 unsigned int chan = CR_CHAN(insn->chanspec);
140 unsigned int mask;
141 int ret;
142
143 if (chan < 8)
144 mask = 0x0000ff;
145 else if (chan < 16)
146 mask = 0x00ff00;
147 else if (chan < 20)
148 mask = 0x0f0000;
149 else
150 mask = 0xf00000;
151
152 ret = comedi_dio_insn_config(dev, s, insn, data, mask);
153 if (ret)
154 return ret;
155
156 subdev_8255_do_config(dev, s);
157
158 return insn->n;
159 }
160
__subdev_8255_init(struct comedi_device * dev,struct comedi_subdevice * s,int (* io)(struct comedi_device *,int,int,int,unsigned long),unsigned long regbase,bool is_mmio)161 static int __subdev_8255_init(struct comedi_device *dev,
162 struct comedi_subdevice *s,
163 int (*io)(struct comedi_device *,
164 int, int, int, unsigned long),
165 unsigned long regbase,
166 bool is_mmio)
167 {
168 struct subdev_8255_private *spriv;
169
170 spriv = comedi_alloc_spriv(s, sizeof(*spriv));
171 if (!spriv)
172 return -ENOMEM;
173
174 if (io)
175 spriv->io = io;
176 else if (is_mmio)
177 spriv->io = subdev_8255_mmio;
178 else
179 spriv->io = subdev_8255_io;
180 spriv->regbase = regbase;
181
182 s->type = COMEDI_SUBD_DIO;
183 s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
184 s->n_chan = 24;
185 s->range_table = &range_digital;
186 s->maxdata = 1;
187 s->insn_bits = subdev_8255_insn;
188 s->insn_config = subdev_8255_insn_config;
189
190 subdev_8255_do_config(dev, s);
191
192 return 0;
193 }
194
195 /**
196 * subdev_8255_init - initialize DIO subdevice for driving I/O mapped 8255
197 * @dev: comedi device owning subdevice
198 * @s: comedi subdevice to initialize
199 * @io: (optional) register I/O call-back function
200 * @regbase: offset of 8255 registers from dev->iobase, or call-back context
201 *
202 * Initializes a comedi subdevice as a DIO subdevice driving an 8255 chip.
203 *
204 * If the optional I/O call-back function is provided, its prototype is of
205 * the following form:
206 *
207 * int my_8255_callback(struct comedi_device *dev,
208 * struct comedi_subdevice *s, int dir, int port,
209 * int data, unsigned long regbase);
210 *
211 * where 'dev', 's', and 'regbase' match the values passed to this function,
212 * 'port' is the 8255 port number 0 to 3 (including the control port), 'dir'
213 * is the direction (0 for read, 1 for write) and 'data' is the value to be
214 * written. It should return 0 if writing or the value read if reading.
215 *
216 * If the optional I/O call-back function is not provided, an internal
217 * call-back function is used which uses consecutive I/O port addresses
218 * starting at dev->iobase + regbase.
219 *
220 * Return: -ENOMEM if failed to allocate memory, zero on success.
221 */
subdev_8255_init(struct comedi_device * dev,struct comedi_subdevice * s,int (* io)(struct comedi_device *,int,int,int,unsigned long),unsigned long regbase)222 int subdev_8255_init(struct comedi_device *dev, struct comedi_subdevice *s,
223 int (*io)(struct comedi_device *,
224 int, int, int, unsigned long),
225 unsigned long regbase)
226 {
227 return __subdev_8255_init(dev, s, io, regbase, false);
228 }
229 EXPORT_SYMBOL_GPL(subdev_8255_init);
230
231 /**
232 * subdev_8255_mm_init - initialize DIO subdevice for driving mmio-mapped 8255
233 * @dev: comedi device owning subdevice
234 * @s: comedi subdevice to initialize
235 * @io: (optional) register I/O call-back function
236 * @regbase: offset of 8255 registers from dev->mmio, or call-back context
237 *
238 * Initializes a comedi subdevice as a DIO subdevice driving an 8255 chip.
239 *
240 * If the optional I/O call-back function is provided, its prototype is of
241 * the following form:
242 *
243 * int my_8255_callback(struct comedi_device *dev,
244 * struct comedi_subdevice *s, int dir, int port,
245 * int data, unsigned long regbase);
246 *
247 * where 'dev', 's', and 'regbase' match the values passed to this function,
248 * 'port' is the 8255 port number 0 to 3 (including the control port), 'dir'
249 * is the direction (0 for read, 1 for write) and 'data' is the value to be
250 * written. It should return 0 if writing or the value read if reading.
251 *
252 * If the optional I/O call-back function is not provided, an internal
253 * call-back function is used which uses consecutive MMIO virtual addresses
254 * starting at dev->mmio + regbase.
255 *
256 * Return: -ENOMEM if failed to allocate memory, zero on success.
257 */
subdev_8255_mm_init(struct comedi_device * dev,struct comedi_subdevice * s,int (* io)(struct comedi_device *,int,int,int,unsigned long),unsigned long regbase)258 int subdev_8255_mm_init(struct comedi_device *dev, struct comedi_subdevice *s,
259 int (*io)(struct comedi_device *,
260 int, int, int, unsigned long),
261 unsigned long regbase)
262 {
263 return __subdev_8255_init(dev, s, io, regbase, true);
264 }
265 EXPORT_SYMBOL_GPL(subdev_8255_mm_init);
266
267 /*
268 * Start of the 8255 standalone device
269 */
270
dev_8255_attach(struct comedi_device * dev,struct comedi_devconfig * it)271 static int dev_8255_attach(struct comedi_device *dev,
272 struct comedi_devconfig *it)
273 {
274 struct comedi_subdevice *s;
275 unsigned long iobase;
276 int ret;
277 int i;
278
279 for (i = 0; i < COMEDI_NDEVCONFOPTS; i++) {
280 iobase = it->options[i];
281 if (!iobase)
282 break;
283 }
284 if (i == 0) {
285 dev_warn(dev->class_dev, "no devices specified\n");
286 return -EINVAL;
287 }
288
289 ret = comedi_alloc_subdevices(dev, i);
290 if (ret)
291 return ret;
292
293 for (i = 0; i < dev->n_subdevices; i++) {
294 s = &dev->subdevices[i];
295 iobase = it->options[i];
296
297 /*
298 * __comedi_request_region() does not set dev->iobase.
299 *
300 * For 8255 devices that are manually attached using
301 * comedi_config, the 'iobase' is the actual I/O port
302 * base address of the chip.
303 */
304 ret = __comedi_request_region(dev, iobase, I8255_SIZE);
305 if (ret) {
306 s->type = COMEDI_SUBD_UNUSED;
307 } else {
308 ret = subdev_8255_init(dev, s, NULL, iobase);
309 if (ret)
310 return ret;
311 }
312 }
313
314 return 0;
315 }
316
dev_8255_detach(struct comedi_device * dev)317 static void dev_8255_detach(struct comedi_device *dev)
318 {
319 struct comedi_subdevice *s;
320 struct subdev_8255_private *spriv;
321 int i;
322
323 for (i = 0; i < dev->n_subdevices; i++) {
324 s = &dev->subdevices[i];
325 if (s->type != COMEDI_SUBD_UNUSED) {
326 spriv = s->private;
327 release_region(spriv->regbase, I8255_SIZE);
328 }
329 }
330 }
331
332 static struct comedi_driver dev_8255_driver = {
333 .driver_name = "8255",
334 .module = THIS_MODULE,
335 .attach = dev_8255_attach,
336 .detach = dev_8255_detach,
337 };
338 module_comedi_driver(dev_8255_driver);
339
340 MODULE_AUTHOR("Comedi http://www.comedi.org");
341 MODULE_DESCRIPTION("Comedi low-level driver");
342 MODULE_LICENSE("GPL");
343