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 Convertion 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)
97 /* OSR4 OSR3 OSR2 OSR1 OSR0 Convertion 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 (MPC624_OSR4 | MPC624_OSR2 | MPC624_OSR1 | MPC624_OSR0)
119 #define MPC624_SPEED_27_5_Hz (MPC624_OSR4 | MPC624_OSR3 )
120 #define MPC624_SPEED_13_75_Hz (MPC624_OSR4 | MPC624_OSR3 | MPC624_OSR0)
121 #define MPC624_SPEED_6_875_Hz (MPC624_OSR4 | MPC624_OSR3 | MPC624_OSR2 | MPC624_OSR1 | MPC624_OSR0)
122 //----------------------------------------------------------------------------
124 unsigned long int ulConvertionRate; // set by mpc624_attach() from driver's parameters
127 #define devpriv ((skel_private *)dev->private)
128 //----------------------------------------------------------------------------
129 static const struct comedi_lrange range_mpc624_bipolar1 = {
132 // BIP_RANGE(1.01) // this is correct,
133 // but my MPC-624 actually seems to have a range of 2.02
137 static const struct comedi_lrange range_mpc624_bipolar10 = {
140 // BIP_RANGE(10.1) // this is correct,
141 // but my MPC-624 actually seems to have a range of 20.2
146 //----------------------------------------------------------------------------
147 static int mpc624_attach(struct comedi_device * dev, struct comedi_devconfig * it);
148 static int mpc624_detach(struct comedi_device * dev);
149 //----------------------------------------------------------------------------
150 static struct comedi_driver driver_mpc624 = {
151 driver_name:"mpc624",
153 attach:mpc624_attach,
157 //----------------------------------------------------------------------------
158 static int mpc624_ai_rinsn(struct comedi_device * dev, struct comedi_subdevice * s,
159 struct comedi_insn * insn, unsigned int * data);
160 //----------------------------------------------------------------------------
161 static int mpc624_attach(struct comedi_device * dev, struct comedi_devconfig * it)
163 struct comedi_subdevice *s;
164 unsigned long iobase;
166 iobase = it->options[0];
167 rt_printk("comedi%d: mpc624 [0x%04lx, ", dev->minor, iobase);
168 if (request_region(iobase, MPC624_SIZE, "mpc624") == NULL) {
169 rt_printk("I/O port(s) in use\n");
173 dev->iobase = iobase;
174 dev->board_name = "mpc624";
176 // Private structure initialization
177 if (alloc_private(dev, sizeof(skel_private)) < 0)
180 switch (it->options[1]) {
182 devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
183 rt_printk("3.52 kHz, ");
186 devpriv->ulConvertionRate = MPC624_SPEED_1_76_kHz;
187 rt_printk("1.76 kHz, ");
190 devpriv->ulConvertionRate = MPC624_SPEED_880_Hz;
191 rt_printk("880 Hz, ");
194 devpriv->ulConvertionRate = MPC624_SPEED_440_Hz;
195 rt_printk("440 Hz, ");
198 devpriv->ulConvertionRate = MPC624_SPEED_220_Hz;
199 rt_printk("220 Hz, ");
202 devpriv->ulConvertionRate = MPC624_SPEED_110_Hz;
203 rt_printk("110 Hz, ");
206 devpriv->ulConvertionRate = MPC624_SPEED_55_Hz;
207 rt_printk("55 Hz, ");
210 devpriv->ulConvertionRate = MPC624_SPEED_27_5_Hz;
211 rt_printk("27.5 Hz, ");
214 devpriv->ulConvertionRate = MPC624_SPEED_13_75_Hz;
215 rt_printk("13.75 Hz, ");
218 devpriv->ulConvertionRate = MPC624_SPEED_6_875_Hz;
219 rt_printk("6.875 Hz, ");
223 ("illegal convertion rate setting! Valid numbers are 0..9. Using 9 => 6.875 Hz, ");
224 devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
227 // Subdevices structures
228 if (alloc_subdevices(dev, 1) < 0)
231 s = dev->subdevices + 0;
232 s->type = COMEDI_SUBD_AI;
233 s->subdev_flags = SDF_READABLE | SDF_DIFF;
235 switch (it->options[1]) {
237 s->maxdata = 0x3FFFFFFF;
238 rt_printk("30 bit, ");
241 switch (it->options[1]) {
243 s->range_table = &range_mpc624_bipolar1;
244 rt_printk("1.01V]: ");
247 s->range_table = &range_mpc624_bipolar10;
248 rt_printk("10.1V]: ");
251 s->insn_read = mpc624_ai_rinsn;
253 rt_printk("attached\n");
258 static int mpc624_detach(struct comedi_device * dev)
260 rt_printk("comedi%d: mpc624: remove\n", dev->minor);
263 release_region(dev->iobase, MPC624_SIZE);
271 static int mpc624_ai_rinsn(struct comedi_device * dev, struct comedi_subdevice * s,
272 struct comedi_insn * insn, unsigned int * data)
275 unsigned long int data_in, data_out;
276 unsigned char ucPort;
278 // WARNING: We always write 0 to GNSWA bit, so the channel range is +-/10.1Vdc
279 outb(insn->chanspec, dev->iobase + MPC624_GNMUXCH);
280 // rt_printk("Channel %d: \n", insn->chanspec);
282 rt_printk("MPC624: Warning, no data to aquire\n");
286 for (n = 0; n < insn->n; n++) {
287 // Trigger the convertion
288 outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
290 outb(MPC624_ADCS | MPC624_ADSCK, dev->iobase + MPC624_ADC);
292 outb(0, dev->iobase + MPC624_ADC);
295 // Wait for the convertion to end
296 for (i = 0; i < TIMEOUT; i++) {
297 ucPort = inb(dev->iobase + MPC624_ADC);
298 if (ucPort & MPC624_ADBUSY)
304 rt_printk("MPC624: timeout (%dms)\n", TIMEOUT);
308 // Start reading data
310 data_out = devpriv->ulConvertionRate;
312 for (i = 0; i < 32; i++) {
314 outb(0, dev->iobase + MPC624_ADC);
317 if (data_out & (1 << 31)) // the next bit is a 1
319 // Set the ADSDI line (send to MPC624)
320 outb(MPC624_ADSDI, dev->iobase + MPC624_ADC);
322 // Set the clock high
323 outb(MPC624_ADSCK | MPC624_ADSDI,
324 dev->iobase + MPC624_ADC);
325 } else // the next bit is a 0
327 // Set the ADSDI line (send to MPC624)
328 outb(0, dev->iobase + MPC624_ADC);
330 // Set the clock high
331 outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
333 // Read ADSDO on high clock (receive from MPC624)
338 MPC624_ADC) & MPC624_ADSDO) >> 4;
344 // Received 32-bit long value consist of:
345 // 31: EOC (End Of Transmission) bit - should be 0
346 // 30: DMY (Dummy) bit - should be 0
347 // 29: SIG (Sign) bit - 1 if the voltage is positive, 0 if negative
348 // 28: MSB (Most Significant Bit) - the first bit of convertion result
350 // 05: LSB (Least Significant Bit) - the last bit of convertion result
351 // 04: sub-LSB - sub-LSBs are basically noise, but when
352 // 03: sub-LSB averaged properly, they can increase convertion
353 // 02: sub-LSB precision up to 29 bits; they can be discarded
354 // 01: sub-LSB without loss of resolution.
357 if (data_in & MPC624_EOC_BIT)
358 rt_printk("MPC624: EOC bit is set (data_in=%lu)!",
360 if (data_in & MPC624_DMY_BIT)
361 rt_printk("MPC624: DMY bit is set (data_in=%lu)!",
363 if (data_in & MPC624_SGN_BIT) // check the sign bit
364 { // The voltage is positive
365 data_in &= 0x3FFFFFFF; // EOC and DMY should be 0, but we will mask them out just to be sure
366 data[n] = data_in; // comedi operates on unsigned numbers, so we don't clear the SGN bit
367 // SGN bit is still set! It's correct, since we're converting to unsigned.
368 } else { // The voltage is negative
369 // data_in contains a number in 30-bit two's complement code and we must deal with it
370 data_in |= MPC624_SGN_BIT;
373 data_in &= ~(MPC624_EOC_BIT | MPC624_DMY_BIT);
374 // clear EOC and DMY bits
375 data_in = 0x20000000 - data_in;
380 // Return the number of samples read/written
384 COMEDI_INITCLEANUP(driver_mpc624);