2 comedi/drivers/mpc624.c
3 Hardware driver for a Micro/sys inc. MPC-624 PC/104 board
5 COMEDI - Linux Control and Measurement Device Interface
6 Copyright (C) 2000 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: Micro/sys MPC-624 PC/104 board
26 Devices: [Micro/sys] MPC-624 (mpc624)
27 Author: Stanislaw Raczynski <sraczynski@op.pl>
28 Updated: Thu, 15 Sep 2005 12:01:18 +0200
31 The Micro/sys MPC-624 board is based on the LTC2440 24-bit sigma-delta
34 Subdevices supported by the driver:
35 - Analog In: supported
36 - Digital I/O: not supported
38 - EEPROM: not supported
40 Configuration Options:
41 [0] - I/O base address
43 Conversion rate RMS noise Effective Number Of Bits
59 #include "../comedidev.h"
61 #include <linux/ioport.h>
62 #include <linux/delay.h>
64 /* Consecutive I/O port addresses */
65 #define MPC624_SIZE 16
67 /* Offsets of different ports */
68 #define MPC624_MASTER_CONTROL 0 /* not used */
69 #define MPC624_GNMUXCH 1 /* Gain, Mux, Channel of ADC */
70 #define MPC624_ADC 2 /* read/write to/from ADC */
71 #define MPC624_EE 3 /* read/write to/from serial EEPROM via I2C */
72 #define MPC624_LEDS 4 /* write to LEDs */
73 #define MPC624_DIO 5 /* read/write to/from digital I/O ports */
74 #define MPC624_IRQ_MASK 6 /* IRQ masking enable/disable */
76 /* Register bits' names */
77 #define MPC624_ADBUSY (1<<5)
78 #define MPC624_ADSDO (1<<4)
79 #define MPC624_ADFO (1<<3)
80 #define MPC624_ADCS (1<<2)
81 #define MPC624_ADSCK (1<<1)
82 #define MPC624_ADSDI (1<<0)
84 /* SDI Speed/Resolution Programming bits */
85 #define MPC624_OSR4 (1<<31)
86 #define MPC624_OSR3 (1<<30)
87 #define MPC624_OSR2 (1<<29)
88 #define MPC624_OSR1 (1<<28)
89 #define MPC624_OSR0 (1<<27)
91 /* 32-bit output value bits' names */
92 #define MPC624_EOC_BIT (1<<31)
93 #define MPC624_DMY_BIT (1<<30)
94 #define MPC624_SGN_BIT (1<<29)
96 /* Conversion speeds */
97 /* OSR4 OSR3 OSR2 OSR1 OSR0 Conversion rate RMS noise ENOB^
98 * X 0 0 0 1 3.52kHz 23uV 17
99 * X 0 0 1 0 1.76kHz 3.5uV 20
100 * X 0 0 1 1 880Hz 2uV 21.3
101 * X 0 1 0 0 440Hz 1.4uV 21.8
102 * X 0 1 0 1 220Hz 1uV 22.4
103 * X 0 1 1 0 110Hz 750uV 22.9
104 * X 0 1 1 1 55Hz 510nV 23.4
105 * X 1 0 0 0 27.5Hz 375nV 24
106 * X 1 0 0 1 13.75Hz 250nV 24.4
107 * X 1 1 1 1 6.875Hz 200nV 24.6
109 * ^ - Effective Number Of Bits
112 #define MPC624_SPEED_3_52_kHz (MPC624_OSR4 | MPC624_OSR0)
113 #define MPC624_SPEED_1_76_kHz (MPC624_OSR4 | MPC624_OSR1)
114 #define MPC624_SPEED_880_Hz (MPC624_OSR4 | MPC624_OSR1 | MPC624_OSR0)
115 #define MPC624_SPEED_440_Hz (MPC624_OSR4 | MPC624_OSR2)
116 #define MPC624_SPEED_220_Hz (MPC624_OSR4 | MPC624_OSR2 | MPC624_OSR0)
117 #define MPC624_SPEED_110_Hz (MPC624_OSR4 | MPC624_OSR2 | MPC624_OSR1)
118 #define MPC624_SPEED_55_Hz \
119 (MPC624_OSR4 | MPC624_OSR2 | MPC624_OSR1 | MPC624_OSR0)
120 #define MPC624_SPEED_27_5_Hz (MPC624_OSR4 | MPC624_OSR3)
121 #define MPC624_SPEED_13_75_Hz (MPC624_OSR4 | MPC624_OSR3 | MPC624_OSR0)
122 #define MPC624_SPEED_6_875_Hz \
123 (MPC624_OSR4 | MPC624_OSR3 | MPC624_OSR2 | MPC624_OSR1 | MPC624_OSR0)
124 /* -------------------------------------------------------------------------- */
125 struct mpc624_private {
127 /* set by mpc624_attach() from driver's parameters */
128 unsigned long int ulConvertionRate;
131 /* -------------------------------------------------------------------------- */
132 static const struct comedi_lrange range_mpc624_bipolar1 = {
135 /* BIP_RANGE(1.01) this is correct, */
136 /* but my MPC-624 actually seems to have a range of 2.02 */
141 static const struct comedi_lrange range_mpc624_bipolar10 = {
144 /* BIP_RANGE(10.1) this is correct, */
145 /* but my MPC-624 actually seems to have a range of 20.2 */
153 static int mpc624_ai_rinsn(struct comedi_device *dev,
154 struct comedi_subdevice *s, struct comedi_insn *insn,
157 struct mpc624_private *devpriv = dev->private;
159 unsigned long int data_in, data_out;
160 unsigned char ucPort;
164 * We always write 0 to GNSWA bit, so the channel range is +-/10.1Vdc
166 outb(insn->chanspec, dev->iobase + MPC624_GNMUXCH);
167 /* printk("Channel %d:\n", insn->chanspec); */
169 printk(KERN_INFO "MPC624: Warning, no data to acquire\n");
173 for (n = 0; n < insn->n; n++) {
174 /* Trigger the conversion */
175 outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
177 outb(MPC624_ADCS | MPC624_ADSCK, dev->iobase + MPC624_ADC);
179 outb(0, dev->iobase + MPC624_ADC);
182 /* Wait for the conversion to end */
183 for (i = 0; i < TIMEOUT; i++) {
184 ucPort = inb(dev->iobase + MPC624_ADC);
185 if (ucPort & MPC624_ADBUSY)
191 printk(KERN_ERR "MPC624: timeout (%dms)\n", TIMEOUT);
195 /* Start reading data */
197 data_out = devpriv->ulConvertionRate;
199 for (i = 0; i < 32; i++) {
200 /* Set the clock low */
201 outb(0, dev->iobase + MPC624_ADC);
204 if (data_out & (1 << 31)) { /* the next bit is a 1 */
205 /* Set the ADSDI line (send to MPC624) */
206 outb(MPC624_ADSDI, dev->iobase + MPC624_ADC);
208 /* Set the clock high */
209 outb(MPC624_ADSCK | MPC624_ADSDI,
210 dev->iobase + MPC624_ADC);
211 } else { /* the next bit is a 0 */
213 /* Set the ADSDI line (send to MPC624) */
214 outb(0, dev->iobase + MPC624_ADC);
216 /* Set the clock high */
217 outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
219 /* Read ADSDO on high clock (receive from MPC624) */
223 (inb(dev->iobase + MPC624_ADC) & MPC624_ADSDO) >> 4;
230 * Received 32-bit long value consist of:
232 * (End Of Transmission) bit - should be 0
234 * (Dummy) bit - should be 0
236 * (Sign) bit- 1 if the voltage is positive,
239 * (Most Significant Bit) - the first bit of
240 * the conversion result
243 * (Least Significant Bit)- the last bit of the
246 * - sub-LSBs are basically noise, but when
247 * averaged properly, they can increase conversion
248 * precision up to 29 bits; they can be discarded
249 * without loss of resolution.
252 if (data_in & MPC624_EOC_BIT)
253 printk(KERN_INFO "MPC624:EOC bit is set (data_in=%lu)!",
255 if (data_in & MPC624_DMY_BIT)
256 printk(KERN_INFO "MPC624:DMY bit is set (data_in=%lu)!",
258 if (data_in & MPC624_SGN_BIT) { /* Volatge is positive */
260 * comedi operates on unsigned numbers, so mask off EOC
261 * and DMY and don't clear the SGN bit
263 data_in &= 0x3FFFFFFF;
265 } else { /* The voltage is negative */
267 * data_in contains a number in 30-bit two's complement
268 * code and we must deal with it
270 data_in |= MPC624_SGN_BIT;
273 data_in &= ~(MPC624_EOC_BIT | MPC624_DMY_BIT);
274 /* clear EOC and DMY bits */
275 data_in = 0x20000000 - data_in;
280 /* Return the number of samples read/written */
284 static int mpc624_attach(struct comedi_device *dev, struct comedi_devconfig *it)
286 struct mpc624_private *devpriv;
287 struct comedi_subdevice *s;
290 ret = comedi_request_region(dev, it->options[0], MPC624_SIZE);
294 devpriv = kzalloc(sizeof(*devpriv), GFP_KERNEL);
297 dev->private = devpriv;
299 switch (it->options[1]) {
301 devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
304 devpriv->ulConvertionRate = MPC624_SPEED_1_76_kHz;
307 devpriv->ulConvertionRate = MPC624_SPEED_880_Hz;
310 devpriv->ulConvertionRate = MPC624_SPEED_440_Hz;
313 devpriv->ulConvertionRate = MPC624_SPEED_220_Hz;
316 devpriv->ulConvertionRate = MPC624_SPEED_110_Hz;
319 devpriv->ulConvertionRate = MPC624_SPEED_55_Hz;
322 devpriv->ulConvertionRate = MPC624_SPEED_27_5_Hz;
325 devpriv->ulConvertionRate = MPC624_SPEED_13_75_Hz;
328 devpriv->ulConvertionRate = MPC624_SPEED_6_875_Hz;
331 devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
334 ret = comedi_alloc_subdevices(dev, 1);
338 s = &dev->subdevices[0];
339 s->type = COMEDI_SUBD_AI;
340 s->subdev_flags = SDF_READABLE | SDF_DIFF;
342 switch (it->options[1]) {
344 s->maxdata = 0x3FFFFFFF;
347 switch (it->options[1]) {
349 s->range_table = &range_mpc624_bipolar1;
352 s->range_table = &range_mpc624_bipolar10;
355 s->insn_read = mpc624_ai_rinsn;
360 static struct comedi_driver mpc624_driver = {
361 .driver_name = "mpc624",
362 .module = THIS_MODULE,
363 .attach = mpc624_attach,
364 .detach = comedi_legacy_detach,
366 module_comedi_driver(mpc624_driver);
368 MODULE_AUTHOR("Comedi http://www.comedi.org");
369 MODULE_DESCRIPTION("Comedi low-level driver");
370 MODULE_LICENSE("GPL");