board/trab/tsc2000.c

   1 /*
   2  * Functions to access the TSC2000 controller on TRAB board (used for scanning
   3  * thermo sensors)
   4  *
   5  * Copyright (C) 2003 Martin Krause, TQ-Systems GmbH, martin.krause@tqs.de
   6  *
   7  * Copyright (C) 2002 DENX Software Engineering, Wolfgang Denk, wd@denx.de
   8  *
   9  * See file CREDITS for list of people who contributed to this
  10  * project.
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License as
  14  * published by the Free Software Foundation; either version 2 of
  15  * the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  25  * MA 02111-1307 USA
  26  */
  27
  28 #include <common.h>
  29 #include <s3c2400.h>
  30 #include "tsc2000.h"
  31
  32 #include "Pt1000_temp_data.h"
  33
  34 /* helper function */
  35 #define abs(value) (((value) < 0) ? ((value)*-1) : (value))
  36
  37 /*
  38  * Maximal allowed deviation between two immediate meassurments of an analog
  39  * thermo channel. 1 DIGIT = 0.0276 °C. This is used to filter sporadic
  40  * "jumps" in measurment.
  41  */
  42 #define MAX_DEVIATION   18      /* unit: DIGITs of adc; 18 DIGIT = 0.5 °C */
  43
  44 void spi_init(void)
  45 {
  46         S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
  47         S3C24X0_SPI * const spi = S3C24X0_GetBase_SPI();
  48         int i;
  49
  50         /* Configure I/O ports. */
  51         gpio->PDCON = (gpio->PDCON & 0xF3FFFF) | 0x040000;
  52         gpio->PGCON = (gpio->PGCON & 0x0F3FFF) | 0x008000;
  53         gpio->PGCON = (gpio->PGCON & 0x0CFFFF) | 0x020000;
  54         gpio->PGCON = (gpio->PGCON & 0x03FFFF) | 0x080000;
  55
  56         CLR_CS_TOUCH();
  57
  58         spi->ch[0].SPPRE = 0x1F; /* Baud-rate ca. 514kHz */
  59         spi->ch[0].SPPIN = 0x01; /* SPI-MOSI holds Level after last bit */
  60         spi->ch[0].SPCON = 0x1A; /* Polling, Prescaler, Master, CPOL=0,
  61                                     CPHA=1 */
  62
  63         /* Dummy byte ensures clock to be low. */
  64         for (i = 0; i < 10; i++) {
  65                 spi->ch[0].SPTDAT = 0xFF;
  66         }
  67         spi_wait_transmit_done();
  68 }
  69
  70
  71 void spi_wait_transmit_done(void)
  72 {
  73         S3C24X0_SPI * const spi = S3C24X0_GetBase_SPI();
  74
  75         while (!(spi->ch[0].SPSTA & 0x01)); /* wait until transfer is done */
  76 }
  77
  78
  79 void tsc2000_write(unsigned short reg, unsigned short data)
  80 {
  81         S3C24X0_SPI * const spi = S3C24X0_GetBase_SPI();
  82         unsigned int command;
  83
  84         SET_CS_TOUCH();
  85         command = reg;
  86         spi->ch[0].SPTDAT = (command & 0xFF00) >> 8;
  87         spi_wait_transmit_done();
  88         spi->ch[0].SPTDAT = (command & 0x00FF);
  89         spi_wait_transmit_done();
  90         spi->ch[0].SPTDAT = (data & 0xFF00) >> 8;
  91         spi_wait_transmit_done();
  92         spi->ch[0].SPTDAT = (data & 0x00FF);
  93         spi_wait_transmit_done();
  94
  95         CLR_CS_TOUCH();
  96 }
  97
  98
  99 unsigned short tsc2000_read (unsigned short reg)
 100 {
 101         unsigned short command, data;
 102         S3C24X0_SPI * const spi = S3C24X0_GetBase_SPI();
 103
 104         SET_CS_TOUCH();
 105         command = 0x8000 | reg;
 106
 107         spi->ch[0].SPTDAT = (command & 0xFF00) >> 8;
 108         spi_wait_transmit_done();
 109         spi->ch[0].SPTDAT = (command & 0x00FF);
 110         spi_wait_transmit_done();
 111
 112         spi->ch[0].SPTDAT = 0xFF;
 113         spi_wait_transmit_done();
 114         data = spi->ch[0].SPRDAT;
 115         spi->ch[0].SPTDAT = 0xFF;
 116         spi_wait_transmit_done();
 117
 118         CLR_CS_TOUCH();
 119         return (spi->ch[0].SPRDAT & 0x0FF) | (data << 8);
 120 }
 121
 122
 123 void tsc2000_set_mux (unsigned int channel)
 124 {
 125         S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
 126
 127         CLR_MUX1_ENABLE; CLR_MUX2_ENABLE;
 128         CLR_MUX3_ENABLE; CLR_MUX4_ENABLE;
 129         switch (channel) {
 130         case 0:
 131                 CLR_MUX0; CLR_MUX1;
 132                 SET_MUX1_ENABLE;
 133                 break;
 134         case 1:
 135                 SET_MUX0; CLR_MUX1;
 136                 SET_MUX1_ENABLE;
 137                 break;
 138         case 2:
 139                 CLR_MUX0; SET_MUX1;
 140                 SET_MUX1_ENABLE;
 141                 break;
 142         case 3:
 143                 SET_MUX0; SET_MUX1;
 144                 SET_MUX1_ENABLE;
 145                 break;
 146         case 4:
 147                 CLR_MUX0; CLR_MUX1;
 148                 SET_MUX2_ENABLE;
 149                 break;
 150         case 5:
 151                 SET_MUX0; CLR_MUX1;
 152                 SET_MUX2_ENABLE;
 153                 break;
 154         case 6:
 155                 CLR_MUX0; SET_MUX1;
 156                 SET_MUX2_ENABLE;
 157                 break;
 158         case 7:
 159                 SET_MUX0; SET_MUX1;
 160                 SET_MUX2_ENABLE;
 161                 break;
 162         case 8:
 163                 CLR_MUX0; CLR_MUX1;
 164                 SET_MUX3_ENABLE;
 165                 break;
 166         case 9:
 167                 SET_MUX0; CLR_MUX1;
 168                 SET_MUX3_ENABLE;
 169                 break;
 170         case 10:
 171                 CLR_MUX0; SET_MUX1;
 172                 SET_MUX3_ENABLE;
 173                 break;
 174         case 11:
 175                 SET_MUX0; SET_MUX1;
 176                 SET_MUX3_ENABLE;
 177                 break;
 178         case 12:
 179                 CLR_MUX0; CLR_MUX1;
 180                 SET_MUX4_ENABLE;
 181                 break;
 182         case 13:
 183                 SET_MUX0; CLR_MUX1;
 184                 SET_MUX4_ENABLE;
 185                 break;
 186         case 14:
 187                 CLR_MUX0; SET_MUX1;
 188                 SET_MUX4_ENABLE;
 189                 break;
 190         case 15:
 191                 SET_MUX0; SET_MUX1;
 192                 SET_MUX4_ENABLE;
 193                 break;
 194         default:
 195                 CLR_MUX0; CLR_MUX1;
 196         }
 197 }
 198
 199
 200 void tsc2000_set_range (unsigned int range)
 201 {
 202         S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
 203
 204         switch (range) {
 205         case 1:
 206                 CLR_SEL_TEMP_V_0; SET_SEL_TEMP_V_1;
 207                 CLR_SEL_TEMP_V_2; CLR_SEL_TEMP_V_3;
 208                 break;
 209         case 2:
 210                 CLR_SEL_TEMP_V_0; CLR_SEL_TEMP_V_1;
 211                 CLR_SEL_TEMP_V_2; SET_SEL_TEMP_V_3;
 212                 break;
 213         case 3:
 214                 SET_SEL_TEMP_V_0; CLR_SEL_TEMP_V_1;
 215                 SET_SEL_TEMP_V_2; CLR_SEL_TEMP_V_3;
 216                 break;
 217         }
 218 }
 219
 220
 221 u16 tsc2000_read_channel (unsigned int channel)
 222 {
 223         u16 res;
 224
 225         tsc2000_set_mux(channel);
 226         udelay(20 * TSC2000_DELAY_BASE);
 227
 228         tsc2000_write(TSC2000_REG_ADC, 0x2036);
 229         adc_wait_conversion_done ();
 230         res = tsc2000_read(TSC2000_REG_AUX1);
 231         return res;
 232 }
 233
 234
 235 s32 tsc2000_contact_temp (void)
 236 {
 237         long adc_pt1000, offset;
 238         long u_pt1000;
 239         long contact_temp;
 240         long temp1, temp2;
 241
 242         tsc2000_reg_init ();
 243         tsc2000_set_range (3);
 244
 245         /*
 246          * Because of sporadic "jumps" in the measured adc values every
 247          * channel is read two times. If there is a significant difference
 248          * between the two measurements, then print an error and do a third
 249          * measurement, because it is very unlikely that a successive third
 250          * measurement goes also wrong.
 251          */
 252         temp1 = tsc2000_read_channel (14);
 253         temp2 = tsc2000_read_channel (14);
 254         if (abs(temp2 - temp1) < MAX_DEVIATION)
 255                 adc_pt1000 = temp2;
 256         else {
 257                 printf ("%s: read adc value (channel 14) exceeded max allowed "
 258                         "deviation: %d * 0.0276 °C\n",
 259                         __FUNCTION__, MAX_DEVIATION);
 260                 printf ("adc value 1: %ld DIGITs\nadc value 2: %ld DIGITs\n",
 261                         temp1, temp2);
 262                 adc_pt1000 = tsc2000_read_channel (14);
 263                 printf ("use (third read) adc value: adc_pt1000 = "
 264                         "%ld DIGITs\n", adc_pt1000);
 265         }
 266         debug ("read channel 14 (pt1000 adc value): %ld\n", adc_pt1000);
 267
 268         temp1 = tsc2000_read_channel (15);
 269         temp2 = tsc2000_read_channel (15);
 270         if (abs(temp2 - temp1) < MAX_DEVIATION)
 271                 offset = temp2;
 272         else {
 273                 printf ("%s: read adc value (channel 15) exceeded max allowed "
 274                         "deviation: %d * 0.0276 °C\n",
 275                         __FUNCTION__, MAX_DEVIATION);
 276                 printf ("adc value 1: %ld DIGITs\nadc value 2: %ld DIGITs\n",
 277                         temp1, temp2);
 278                 offset = tsc2000_read_channel (15);
 279                 printf ("use (third read) adc value: offset = %ld DIGITs\n",
 280                         offset);
 281         }
 282         debug ("read channel 15 (offset): %ld\n", offset);
 283
 284         /*
 285          * Formula for calculating voltage drop on PT1000 resistor: u_pt1000 =
 286          * x_range3 * (adc_raw - offset) / 10. Formula to calculate x_range3:
 287          * x_range3 = (2500 * (1000000 + err_vref + err_amp3)) / (4095*6). The
 288          * error correction Values err_vref and err_amp3 are assumed as 0 in
 289          * u-boot, because this could cause only a very small error (< 1%).
 290          */
 291         u_pt1000 = (101750 * (adc_pt1000 - offset)) / 10;
 292         debug ("u_pt1000: %ld\n", u_pt1000);
 293
 294         if (tsc2000_interpolate(u_pt1000, Pt1000_temp_table,
 295                                 &contact_temp) == -1) {
 296                 printf ("%s: error interpolating PT1000 vlaue\n",
 297                          __FUNCTION__);
 298                 return (-1000);
 299         }
 300         debug ("contact_temp: %ld\n", contact_temp);
 301
 302         return contact_temp;
 303 }
 304
 305
 306 void tsc2000_reg_init (void)
 307 {
 308         S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();
 309
 310         tsc2000_write(TSC2000_REG_ADC, 0x2036);
 311         tsc2000_write(TSC2000_REG_REF, 0x0011);
 312         tsc2000_write(TSC2000_REG_DACCTL, 0x0000);
 313
 314         CON_MUX0;
 315         CON_MUX1;
 316
 317         CON_MUX1_ENABLE;
 318         CON_MUX2_ENABLE;
 319         CON_MUX3_ENABLE;
 320         CON_MUX4_ENABLE;
 321
 322         CON_SEL_TEMP_V_0;
 323         CON_SEL_TEMP_V_1;
 324         CON_SEL_TEMP_V_2;
 325         CON_SEL_TEMP_V_3;
 326
 327         tsc2000_set_mux(0);
 328         tsc2000_set_range(0);
 329 }
 330
 331
 332 int tsc2000_interpolate(long value, long data[][2], long *result)
 333 {
 334         int i;
 335
 336         /* the data is sorted and the first element is upper
 337          * limit so we can easily check for out-of-band values
 338          */
 339         if (data[0][0] < value || data[1][0] > value)
 340                 return -1;
 341
 342         i = 1;
 343         while (data[i][0] < value)
 344                 i++;
 345
 346         /* To prevent overflow we have to store the intermediate
 347            result in 'long long'.
 348         */
 349
 350         *result = data[i-1][1] +
 351                 ((unsigned long long)(data[i][1] - data[i-1][1])
 352                  * (unsigned long long)(value - data[i-1][0]))
 353                 / (data[i][0] - data[i-1][0]);
 354
 355         return 0;
 356 }
 357
 358
 359 void adc_wait_conversion_done(void)
 360 {
 361         while (!(tsc2000_read(TSC2000_REG_ADC) & (1 << 14)));
 362 }