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 //----------------------------------------------------------------------------
123 struct skel_private {
125 unsigned long int ulConvertionRate; // set by mpc624_attach() from driver's parameters
129 #define devpriv ((struct skel_private *)dev->private)
130 //----------------------------------------------------------------------------
131 static const struct comedi_lrange range_mpc624_bipolar1 = {
134 // BIP_RANGE(1.01) // this is correct,
135 // but my MPC-624 actually seems to have a range of 2.02
139 static const struct comedi_lrange range_mpc624_bipolar10 = {
142 // BIP_RANGE(10.1) // this is correct,
143 // but my MPC-624 actually seems to have a range of 20.2
148 //----------------------------------------------------------------------------
149 static int mpc624_attach(struct comedi_device * dev, struct comedi_devconfig * it);
150 static int mpc624_detach(struct comedi_device * dev);
151 //----------------------------------------------------------------------------
152 static struct comedi_driver driver_mpc624 = {
153 driver_name:"mpc624",
155 attach:mpc624_attach,
159 //----------------------------------------------------------------------------
160 static int mpc624_ai_rinsn(struct comedi_device * dev, struct comedi_subdevice * s,
161 struct comedi_insn * insn, unsigned int * data);
162 //----------------------------------------------------------------------------
163 static int mpc624_attach(struct comedi_device * dev, struct comedi_devconfig * it)
165 struct comedi_subdevice *s;
166 unsigned long iobase;
168 iobase = it->options[0];
169 rt_printk("comedi%d: mpc624 [0x%04lx, ", dev->minor, iobase);
170 if (request_region(iobase, MPC624_SIZE, "mpc624") == NULL) {
171 rt_printk("I/O port(s) in use\n");
175 dev->iobase = iobase;
176 dev->board_name = "mpc624";
178 // Private structure initialization
179 if (alloc_private(dev, sizeof(struct skel_private)) < 0)
182 switch (it->options[1]) {
184 devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
185 rt_printk("3.52 kHz, ");
188 devpriv->ulConvertionRate = MPC624_SPEED_1_76_kHz;
189 rt_printk("1.76 kHz, ");
192 devpriv->ulConvertionRate = MPC624_SPEED_880_Hz;
193 rt_printk("880 Hz, ");
196 devpriv->ulConvertionRate = MPC624_SPEED_440_Hz;
197 rt_printk("440 Hz, ");
200 devpriv->ulConvertionRate = MPC624_SPEED_220_Hz;
201 rt_printk("220 Hz, ");
204 devpriv->ulConvertionRate = MPC624_SPEED_110_Hz;
205 rt_printk("110 Hz, ");
208 devpriv->ulConvertionRate = MPC624_SPEED_55_Hz;
209 rt_printk("55 Hz, ");
212 devpriv->ulConvertionRate = MPC624_SPEED_27_5_Hz;
213 rt_printk("27.5 Hz, ");
216 devpriv->ulConvertionRate = MPC624_SPEED_13_75_Hz;
217 rt_printk("13.75 Hz, ");
220 devpriv->ulConvertionRate = MPC624_SPEED_6_875_Hz;
221 rt_printk("6.875 Hz, ");
225 ("illegal convertion rate setting! Valid numbers are 0..9. Using 9 => 6.875 Hz, ");
226 devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
229 // Subdevices structures
230 if (alloc_subdevices(dev, 1) < 0)
233 s = dev->subdevices + 0;
234 s->type = COMEDI_SUBD_AI;
235 s->subdev_flags = SDF_READABLE | SDF_DIFF;
237 switch (it->options[1]) {
239 s->maxdata = 0x3FFFFFFF;
240 rt_printk("30 bit, ");
243 switch (it->options[1]) {
245 s->range_table = &range_mpc624_bipolar1;
246 rt_printk("1.01V]: ");
249 s->range_table = &range_mpc624_bipolar10;
250 rt_printk("10.1V]: ");
253 s->insn_read = mpc624_ai_rinsn;
255 rt_printk("attached\n");
260 static int mpc624_detach(struct comedi_device * dev)
262 rt_printk("comedi%d: mpc624: remove\n", dev->minor);
265 release_region(dev->iobase, MPC624_SIZE);
273 static int mpc624_ai_rinsn(struct comedi_device * dev, struct comedi_subdevice * s,
274 struct comedi_insn * insn, unsigned int * data)
277 unsigned long int data_in, data_out;
278 unsigned char ucPort;
280 // WARNING: We always write 0 to GNSWA bit, so the channel range is +-/10.1Vdc
281 outb(insn->chanspec, dev->iobase + MPC624_GNMUXCH);
282 // rt_printk("Channel %d: \n", insn->chanspec);
284 rt_printk("MPC624: Warning, no data to aquire\n");
288 for (n = 0; n < insn->n; n++) {
289 // Trigger the convertion
290 outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
292 outb(MPC624_ADCS | MPC624_ADSCK, dev->iobase + MPC624_ADC);
294 outb(0, dev->iobase + MPC624_ADC);
297 // Wait for the convertion to end
298 for (i = 0; i < TIMEOUT; i++) {
299 ucPort = inb(dev->iobase + MPC624_ADC);
300 if (ucPort & MPC624_ADBUSY)
306 rt_printk("MPC624: timeout (%dms)\n", TIMEOUT);
310 // Start reading data
312 data_out = devpriv->ulConvertionRate;
314 for (i = 0; i < 32; i++) {
316 outb(0, dev->iobase + MPC624_ADC);
319 if (data_out & (1 << 31)) // the next bit is a 1
321 // Set the ADSDI line (send to MPC624)
322 outb(MPC624_ADSDI, dev->iobase + MPC624_ADC);
324 // Set the clock high
325 outb(MPC624_ADSCK | MPC624_ADSDI,
326 dev->iobase + MPC624_ADC);
327 } else // the next bit is a 0
329 // Set the ADSDI line (send to MPC624)
330 outb(0, dev->iobase + MPC624_ADC);
332 // Set the clock high
333 outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
335 // Read ADSDO on high clock (receive from MPC624)
340 MPC624_ADC) & MPC624_ADSDO) >> 4;
346 // Received 32-bit long value consist of:
347 // 31: EOC (End Of Transmission) bit - should be 0
348 // 30: DMY (Dummy) bit - should be 0
349 // 29: SIG (Sign) bit - 1 if the voltage is positive, 0 if negative
350 // 28: MSB (Most Significant Bit) - the first bit of convertion result
352 // 05: LSB (Least Significant Bit) - the last bit of convertion result
353 // 04: sub-LSB - sub-LSBs are basically noise, but when
354 // 03: sub-LSB averaged properly, they can increase convertion
355 // 02: sub-LSB precision up to 29 bits; they can be discarded
356 // 01: sub-LSB without loss of resolution.
359 if (data_in & MPC624_EOC_BIT)
360 rt_printk("MPC624: EOC bit is set (data_in=%lu)!",
362 if (data_in & MPC624_DMY_BIT)
363 rt_printk("MPC624: DMY bit is set (data_in=%lu)!",
365 if (data_in & MPC624_SGN_BIT) // check the sign bit
366 { // The voltage is positive
367 data_in &= 0x3FFFFFFF; // EOC and DMY should be 0, but we will mask them out just to be sure
368 data[n] = data_in; // comedi operates on unsigned numbers, so we don't clear the SGN bit
369 // SGN bit is still set! It's correct, since we're converting to unsigned.
370 } else { // The voltage is negative
371 // data_in contains a number in 30-bit two's complement code and we must deal with it
372 data_in |= MPC624_SGN_BIT;
375 data_in &= ~(MPC624_EOC_BIT | MPC624_DMY_BIT);
376 // clear EOC and DMY bits
377 data_in = 0x20000000 - data_in;
382 // Return the number of samples read/written
386 COMEDI_INITCLEANUP(driver_mpc624);