drivers/staging/comedi/drivers/mpc624.c

   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 <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     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 <sraczynski@op.pl>
  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 mpc624_private {
 126
 127         /*  set by mpc624_attach() from driver's parameters */
 128         unsigned long int ulConvertionRate;
 129 };
 130
 131 /* -------------------------------------------------------------------------- */
 132 static const struct comedi_lrange range_mpc624_bipolar1 = {
 133         1,
 134         {
 135 /* BIP_RANGE(1.01)  this is correct, */
 136          /*  but my MPC-624 actually seems to have a range of 2.02 */
 137          BIP_RANGE(2.02)
 138          }
 139 };
 140
 141 static const struct comedi_lrange range_mpc624_bipolar10 = {
 142         1,
 143         {
 144 /* BIP_RANGE(10.1)   this is correct, */
 145          /*  but my MPC-624 actually seems to have a range of 20.2 */
 146          BIP_RANGE(20.2)
 147          }
 148 };
 149
 150 /* Timeout 200ms */
 151 #define TIMEOUT 200
 152
 153 static int mpc624_ai_rinsn(struct comedi_device *dev,
 154                            struct comedi_subdevice *s, struct comedi_insn *insn,
 155                            unsigned int *data)
 156 {
 157         struct mpc624_private *devpriv = dev->private;
 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 mpc624_private *devpriv;
 287         struct comedi_subdevice *s;
 288         int ret;
 289
 290         ret = comedi_request_region(dev, it->options[0], MPC624_SIZE);
 291         if (ret)
 292                 return ret;
 293
 294         devpriv = kzalloc(sizeof(*devpriv), GFP_KERNEL);
 295         if (!devpriv)
 296                 return -ENOMEM;
 297         dev->private = devpriv;
 298
 299         switch (it->options[1]) {
 300         case 0:
 301                 devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
 302                 break;
 303         case 1:
 304                 devpriv->ulConvertionRate = MPC624_SPEED_1_76_kHz;
 305                 break;
 306         case 2:
 307                 devpriv->ulConvertionRate = MPC624_SPEED_880_Hz;
 308                 break;
 309         case 3:
 310                 devpriv->ulConvertionRate = MPC624_SPEED_440_Hz;
 311                 break;
 312         case 4:
 313                 devpriv->ulConvertionRate = MPC624_SPEED_220_Hz;
 314                 break;
 315         case 5:
 316                 devpriv->ulConvertionRate = MPC624_SPEED_110_Hz;
 317                 break;
 318         case 6:
 319                 devpriv->ulConvertionRate = MPC624_SPEED_55_Hz;
 320                 break;
 321         case 7:
 322                 devpriv->ulConvertionRate = MPC624_SPEED_27_5_Hz;
 323                 break;
 324         case 8:
 325                 devpriv->ulConvertionRate = MPC624_SPEED_13_75_Hz;
 326                 break;
 327         case 9:
 328                 devpriv->ulConvertionRate = MPC624_SPEED_6_875_Hz;
 329                 break;
 330         default:
 331                 devpriv->ulConvertionRate = MPC624_SPEED_3_52_kHz;
 332         }
 333
 334         ret = comedi_alloc_subdevices(dev, 1);
 335         if (ret)
 336                 return ret;
 337
 338         s = &dev->subdevices[0];
 339         s->type = COMEDI_SUBD_AI;
 340         s->subdev_flags = SDF_READABLE | SDF_DIFF;
 341         s->n_chan = 8;
 342         switch (it->options[1]) {
 343         default:
 344                 s->maxdata = 0x3FFFFFFF;
 345         }
 346
 347         switch (it->options[1]) {
 348         case 0:
 349                 s->range_table = &range_mpc624_bipolar1;
 350                 break;
 351         default:
 352                 s->range_table = &range_mpc624_bipolar10;
 353         }
 354         s->len_chanlist = 1;
 355         s->insn_read = mpc624_ai_rinsn;
 356
 357         return 1;
 358 }
 359
 360 static struct comedi_driver mpc624_driver = {
 361         .driver_name    = "mpc624",
 362         .module         = THIS_MODULE,
 363         .attach         = mpc624_attach,
 364         .detach         = comedi_legacy_detach,
 365 };
 366 module_comedi_driver(mpc624_driver);
 367
 368 MODULE_AUTHOR("Comedi http://www.comedi.org");
 369 MODULE_DESCRIPTION("Comedi low-level driver");
 370 MODULE_LICENSE("GPL");