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mpc624.c
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1 /*
2  comedi/drivers/mpc624.c
3  Hardware driver for a Micro/sys inc. MPC-624 PC/104 board
4 
5  COMEDI - Linux Control and Measurement Device Interface
6  Copyright (C) 2000 David A. Schleef <[email protected]>
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: mpc624
25 Description: Micro/sys MPC-624 PC/104 board
26 Devices: [Micro/sys] MPC-624 (mpc624)
27 Author: Stanislaw Raczynski <[email protected]>
28 Updated: Thu, 15 Sep 2005 12:01:18 +0200
29 Status: working
30 
31  The Micro/sys MPC-624 board is based on the LTC2440 24-bit sigma-delta
32  ADC chip.
33 
34  Subdevices supported by the driver:
35  - Analog In: supported
36  - Digital I/O: not supported
37  - LEDs: not supported
38  - EEPROM: not supported
39 
40 Configuration Options:
41  [0] - I/O base address
42  [1] - conversion rate
43  Conversion rate RMS noise Effective Number Of Bits
44  0 3.52kHz 23uV 17
45  1 1.76kHz 3.5uV 20
46  2 880Hz 2uV 21.3
47  3 440Hz 1.4uV 21.8
48  4 220Hz 1uV 22.4
49  5 110Hz 750uV 22.9
50  6 55Hz 510nV 23.4
51  7 27.5Hz 375nV 24
52  8 13.75Hz 250nV 24.4
53  9 6.875Hz 200nV 24.6
54  [2] - voltage range
55  0 -1.01V .. +1.01V
56  1 -10.1V .. +10.1V
57 */
58 
59 #include "../comedidev.h"
60 
61 #include <linux/ioport.h>
62 #include <linux/delay.h>
63 
64 /* Consecutive I/O port addresses */
65 #define MPC624_SIZE 16
66 
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 */
75 
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)
83 
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)
90 
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)
95 
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
108  *
109  * ^ - Effective Number Of Bits
110  */
111 
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 skel_private {
126 
127  /* set by mpc624_attach() from driver's parameters */
128  unsigned long int ulConvertionRate;
129 };
130 
131 #define devpriv ((struct skel_private *)dev->private)
132 /* -------------------------------------------------------------------------- */
133 static const struct comedi_lrange range_mpc624_bipolar1 = {
134  1,
135  {
136 /* BIP_RANGE(1.01) this is correct, */
137  /* but my MPC-624 actually seems to have a range of 2.02 */
138  BIP_RANGE(2.02)
139  }
140 };
141 
142 static const struct comedi_lrange range_mpc624_bipolar10 = {
143  1,
144  {
145 /* BIP_RANGE(10.1) this is correct, */
146  /* but my MPC-624 actually seems to have a range of 20.2 */
147  BIP_RANGE(20.2)
148  }
149 };
150 
151 /* Timeout 200ms */
152 #define TIMEOUT 200
153 
154 static int mpc624_ai_rinsn(struct comedi_device *dev,
155  struct comedi_subdevice *s, struct comedi_insn *insn,
156  unsigned int *data)
157 {
158  int n, i;
159  unsigned long int data_in, data_out;
160  unsigned char ucPort;
161 
162  /*
163  * WARNING:
164  * We always write 0 to GNSWA bit, so the channel range is +-/10.1Vdc
165  */
166  outb(insn->chanspec, dev->iobase + MPC624_GNMUXCH);
167 /* printk("Channel %d:\n", insn->chanspec); */
168  if (!insn->n) {
169  printk(KERN_INFO "MPC624: Warning, no data to acquire\n");
170  return 0;
171  }
172 
173  for (n = 0; n < insn->n; n++) {
174  /* Trigger the conversion */
175  outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
176  udelay(1);
177  outb(MPC624_ADCS | MPC624_ADSCK, dev->iobase + MPC624_ADC);
178  udelay(1);
179  outb(0, dev->iobase + MPC624_ADC);
180  udelay(1);
181 
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)
186  udelay(1000);
187  else
188  break;
189  }
190  if (i == TIMEOUT) {
191  printk(KERN_ERR "MPC624: timeout (%dms)\n", TIMEOUT);
192  data[n] = 0;
193  return -ETIMEDOUT;
194  }
195  /* Start reading data */
196  data_in = 0;
197  data_out = devpriv->ulConvertionRate;
198  udelay(1);
199  for (i = 0; i < 32; i++) {
200  /* Set the clock low */
201  outb(0, dev->iobase + MPC624_ADC);
202  udelay(1);
203 
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);
207  udelay(1);
208  /* Set the clock high */
209  outb(MPC624_ADSCK | MPC624_ADSDI,
210  dev->iobase + MPC624_ADC);
211  } else { /* the next bit is a 0 */
212 
213  /* Set the ADSDI line (send to MPC624) */
214  outb(0, dev->iobase + MPC624_ADC);
215  udelay(1);
216  /* Set the clock high */
217  outb(MPC624_ADSCK, dev->iobase + MPC624_ADC);
218  }
219  /* Read ADSDO on high clock (receive from MPC624) */
220  udelay(1);
221  data_in <<= 1;
222  data_in |=
223  (inb(dev->iobase + MPC624_ADC) & MPC624_ADSDO) >> 4;
224  udelay(1);
225 
226  data_out <<= 1;
227  }
228 
229  /*
230  * Received 32-bit long value consist of:
231  * 31: EOC -
232  * (End Of Transmission) bit - should be 0
233  * 30: DMY
234  * (Dummy) bit - should be 0
235  * 29: SIG
236  * (Sign) bit- 1 if the voltage is positive,
237  * 0 if negative
238  * 28: MSB
239  * (Most Significant Bit) - the first bit of
240  * the conversion result
241  * ....
242  * 05: LSB
243  * (Least Significant Bit)- the last bit of the
244  * conversion result
245  * 04-00: sub-LSB
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.
250  */
251 
252  if (data_in & MPC624_EOC_BIT)
253  printk(KERN_INFO "MPC624:EOC bit is set (data_in=%lu)!",
254  data_in);
255  if (data_in & MPC624_DMY_BIT)
256  printk(KERN_INFO "MPC624:DMY bit is set (data_in=%lu)!",
257  data_in);
258  if (data_in & MPC624_SGN_BIT) { /* Volatge is positive */
259  /*
260  * comedi operates on unsigned numbers, so mask off EOC
261  * and DMY and don't clear the SGN bit
262  */
263  data_in &= 0x3FFFFFFF;
264  data[n] = data_in;
265  } else { /* The voltage is negative */
266  /*
267  * data_in contains a number in 30-bit two's complement
268  * code and we must deal with it
269  */
270  data_in |= MPC624_SGN_BIT;
271  data_in = ~data_in;
272  data_in += 1;
273  data_in &= ~(MPC624_EOC_BIT | MPC624_DMY_BIT);
274  /* clear EOC and DMY bits */
275  data_in = 0x20000000 - data_in;
276  data[n] = data_in;
277  }
278  }
279 
280  /* Return the number of samples read/written */
281  return n;
282 }
283 
284 static int mpc624_attach(struct comedi_device *dev, struct comedi_devconfig *it)
285 {
286  struct comedi_subdevice *s;
287  unsigned long iobase;
288  int ret;
289 
290  iobase = it->options[0];
291  printk(KERN_INFO "comedi%d: mpc624 [0x%04lx, ", dev->minor, iobase);
292  if (request_region(iobase, MPC624_SIZE, "mpc624") == NULL) {
293  printk(KERN_ERR "I/O port(s) in use\n");
294  return -EIO;
295  }
296 
297  dev->iobase = iobase;
298  dev->board_name = "mpc624";
299 
300  /* Private structure initialization */
301  if (alloc_private(dev, sizeof(struct skel_private)) < 0)
302  return -ENOMEM;
303 
304  switch (it->options[1]) {
305  case 0:
306  devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
307  printk(KERN_INFO "3.52 kHz, ");
308  break;
309  case 1:
310  devpriv->ulConvertionRate = MPC624_SPEED_1_76_kHz;
311  printk(KERN_INFO "1.76 kHz, ");
312  break;
313  case 2:
314  devpriv->ulConvertionRate = MPC624_SPEED_880_Hz;
315  printk(KERN_INFO "880 Hz, ");
316  break;
317  case 3:
318  devpriv->ulConvertionRate = MPC624_SPEED_440_Hz;
319  printk(KERN_INFO "440 Hz, ");
320  break;
321  case 4:
322  devpriv->ulConvertionRate = MPC624_SPEED_220_Hz;
323  printk(KERN_INFO "220 Hz, ");
324  break;
325  case 5:
326  devpriv->ulConvertionRate = MPC624_SPEED_110_Hz;
327  printk(KERN_INFO "110 Hz, ");
328  break;
329  case 6:
330  devpriv->ulConvertionRate = MPC624_SPEED_55_Hz;
331  printk(KERN_INFO "55 Hz, ");
332  break;
333  case 7:
334  devpriv->ulConvertionRate = MPC624_SPEED_27_5_Hz;
335  printk(KERN_INFO "27.5 Hz, ");
336  break;
337  case 8:
338  devpriv->ulConvertionRate = MPC624_SPEED_13_75_Hz;
339  printk(KERN_INFO "13.75 Hz, ");
340  break;
341  case 9:
342  devpriv->ulConvertionRate = MPC624_SPEED_6_875_Hz;
343  printk(KERN_INFO "6.875 Hz, ");
344  break;
345  default:
346  printk
347  (KERN_ERR "illegal conversion rate setting!"
348  " Valid numbers are 0..9. Using 9 => 6.875 Hz, ");
349  devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
350  }
351 
352  ret = comedi_alloc_subdevices(dev, 1);
353  if (ret)
354  return ret;
355 
356  s = &dev->subdevices[0];
357  s->type = COMEDI_SUBD_AI;
358  s->subdev_flags = SDF_READABLE | SDF_DIFF;
359  s->n_chan = 8;
360  switch (it->options[1]) {
361  default:
362  s->maxdata = 0x3FFFFFFF;
363  printk(KERN_INFO "30 bit, ");
364  }
365 
366  switch (it->options[1]) {
367  case 0:
368  s->range_table = &range_mpc624_bipolar1;
369  printk(KERN_INFO "1.01V]: ");
370  break;
371  default:
372  s->range_table = &range_mpc624_bipolar10;
373  printk(KERN_INFO "10.1V]: ");
374  }
375  s->len_chanlist = 1;
376  s->insn_read = mpc624_ai_rinsn;
377 
378  printk(KERN_INFO "attached\n");
379 
380  return 1;
381 }
382 
383 static void mpc624_detach(struct comedi_device *dev)
384 {
385  if (dev->iobase)
386  release_region(dev->iobase, MPC624_SIZE);
387 }
388 
389 static struct comedi_driver mpc624_driver = {
390  .driver_name = "mpc624",
391  .module = THIS_MODULE,
392  .attach = mpc624_attach,
393  .detach = mpc624_detach
394 };
395 module_comedi_driver(mpc624_driver);
396 
397 MODULE_AUTHOR("Comedi http://www.comedi.org");
398 MODULE_DESCRIPTION("Comedi low-level driver");
399 MODULE_LICENSE("GPL");
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