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/*
* Functions to access the TSC2000 controller on TRAB board (used for scanning
* thermo sensors)
*
* Copyright (C) 2003 Martin Krause, TQ-Systems GmbH, martin.krause@tqs.de
*
* Copyright (C) 2002 DENX Software Engineering, Wolfgang Denk, wd@denx.de
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <s3c2400.h>
#include <asm/io.h>
#include <div64.h>
#include "tsc2000.h"
#include "Pt1000_temp_data.h"
/* helper function */
#define abs(value) (((value) < 0) ? ((value)*-1) : (value))
/*
* Maximal allowed deviation between two immediate meassurments of an analog
* thermo channel. 1 DIGIT = 0.0276 °C. This is used to filter sporadic
* "jumps" in measurment.
*/
#define MAX_DEVIATION 18 /* unit: DIGITs of adc; 18 DIGIT = 0.5 °C */
void tsc2000_spi_init(void)
{
struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
struct s3c24x0_spi * const spi = s3c24x0_get_base_spi();
int i;
/* Configure I/O ports. */
gpio->PDCON = (gpio->PDCON & 0xF3FFFF) | 0x040000;
gpio->PGCON = (gpio->PGCON & 0x0F3FFF) | 0x008000;
gpio->PGCON = (gpio->PGCON & 0x0CFFFF) | 0x020000;
gpio->PGCON = (gpio->PGCON & 0x03FFFF) | 0x080000;
CLR_CS_TOUCH();
spi->ch[0].SPPRE = 0x1F; /* Baud-rate ca. 514kHz */
spi->ch[0].SPPIN = 0x01; /* SPI-MOSI holds Level after last bit */
spi->ch[0].SPCON = 0x1A; /* Polling, Prescaler, Master, CPOL=0,
CPHA=1 */
/* Dummy byte ensures clock to be low. */
for (i = 0; i < 10; i++) {
spi->ch[0].SPTDAT = 0xFF;
}
spi_wait_transmit_done();
}
void spi_wait_transmit_done(void)
{
struct s3c24x0_spi * const spi = s3c24x0_get_base_spi();
while (!(spi->ch[0].SPSTA & 0x01)); /* wait until transfer is done */
}
void tsc2000_write(unsigned short reg, unsigned short data)
{
struct s3c24x0_spi * const spi = s3c24x0_get_base_spi();
unsigned int command;
SET_CS_TOUCH();
command = reg;
spi->ch[0].SPTDAT = (command & 0xFF00) >> 8;
spi_wait_transmit_done();
spi->ch[0].SPTDAT = (command & 0x00FF);
spi_wait_transmit_done();
spi->ch[0].SPTDAT = (data & 0xFF00) >> 8;
spi_wait_transmit_done();
spi->ch[0].SPTDAT = (data & 0x00FF);
spi_wait_transmit_done();
CLR_CS_TOUCH();
}
unsigned short tsc2000_read (unsigned short reg)
{
unsigned short command, data;
struct s3c24x0_spi * const spi = s3c24x0_get_base_spi();
SET_CS_TOUCH();
command = 0x8000 | reg;
spi->ch[0].SPTDAT = (command & 0xFF00) >> 8;
spi_wait_transmit_done();
spi->ch[0].SPTDAT = (command & 0x00FF);
spi_wait_transmit_done();
spi->ch[0].SPTDAT = 0xFF;
spi_wait_transmit_done();
data = spi->ch[0].SPRDAT;
spi->ch[0].SPTDAT = 0xFF;
spi_wait_transmit_done();
CLR_CS_TOUCH();
return (spi->ch[0].SPRDAT & 0x0FF) | (data << 8);
}
void tsc2000_set_mux (unsigned int channel)
{
struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
CLR_MUX1_ENABLE; CLR_MUX2_ENABLE;
CLR_MUX3_ENABLE; CLR_MUX4_ENABLE;
switch (channel) {
case 0:
CLR_MUX0; CLR_MUX1;
SET_MUX1_ENABLE;
break;
case 1:
SET_MUX0; CLR_MUX1;
SET_MUX1_ENABLE;
break;
case 2:
CLR_MUX0; SET_MUX1;
SET_MUX1_ENABLE;
break;
case 3:
SET_MUX0; SET_MUX1;
SET_MUX1_ENABLE;
break;
case 4:
CLR_MUX0; CLR_MUX1;
SET_MUX2_ENABLE;
break;
case 5:
SET_MUX0; CLR_MUX1;
SET_MUX2_ENABLE;
break;
case 6:
CLR_MUX0; SET_MUX1;
SET_MUX2_ENABLE;
break;
case 7:
SET_MUX0; SET_MUX1;
SET_MUX2_ENABLE;
break;
case 8:
CLR_MUX0; CLR_MUX1;
SET_MUX3_ENABLE;
break;
case 9:
SET_MUX0; CLR_MUX1;
SET_MUX3_ENABLE;
break;
case 10:
CLR_MUX0; SET_MUX1;
SET_MUX3_ENABLE;
break;
case 11:
SET_MUX0; SET_MUX1;
SET_MUX3_ENABLE;
break;
case 12:
CLR_MUX0; CLR_MUX1;
SET_MUX4_ENABLE;
break;
case 13:
SET_MUX0; CLR_MUX1;
SET_MUX4_ENABLE;
break;
case 14:
CLR_MUX0; SET_MUX1;
SET_MUX4_ENABLE;
break;
case 15:
SET_MUX0; SET_MUX1;
SET_MUX4_ENABLE;
break;
default:
CLR_MUX0; CLR_MUX1;
}
}
void tsc2000_set_range (unsigned int range)
{
struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
switch (range) {
case 1:
CLR_SEL_TEMP_V_0; SET_SEL_TEMP_V_1;
CLR_SEL_TEMP_V_2; CLR_SEL_TEMP_V_3;
break;
case 2:
CLR_SEL_TEMP_V_0; CLR_SEL_TEMP_V_1;
CLR_SEL_TEMP_V_2; SET_SEL_TEMP_V_3;
break;
case 3:
SET_SEL_TEMP_V_0; CLR_SEL_TEMP_V_1;
SET_SEL_TEMP_V_2; CLR_SEL_TEMP_V_3;
break;
}
}
u16 tsc2000_read_channel (unsigned int channel)
{
u16 res;
tsc2000_set_mux(channel);
udelay(20 * TSC2000_DELAY_BASE);
tsc2000_write(TSC2000_REG_ADC, 0x2036);
adc_wait_conversion_done ();
res = tsc2000_read(TSC2000_REG_AUX1);
return res;
}
s32 tsc2000_contact_temp (void)
{
long adc_pt1000, offset;
long u_pt1000;
long contact_temp;
long temp1, temp2;
tsc2000_reg_init ();
tsc2000_set_range (3);
/*
* Because of sporadic "jumps" in the measured adc values every
* channel is read two times. If there is a significant difference
* between the two measurements, then print an error and do a third
* measurement, because it is very unlikely that a successive third
* measurement goes also wrong.
*/
temp1 = tsc2000_read_channel (14);
temp2 = tsc2000_read_channel (14);
if (abs(temp2 - temp1) < MAX_DEVIATION)
adc_pt1000 = temp2;
else {
printf ("%s: read adc value (channel 14) exceeded max allowed "
"deviation: %d * 0.0276 °C\n",
__FUNCTION__, MAX_DEVIATION);
printf ("adc value 1: %ld DIGITs\nadc value 2: %ld DIGITs\n",
temp1, temp2);
adc_pt1000 = tsc2000_read_channel (14);
printf ("use (third read) adc value: adc_pt1000 = "
"%ld DIGITs\n", adc_pt1000);
}
debug ("read channel 14 (pt1000 adc value): %ld\n", adc_pt1000);
temp1 = tsc2000_read_channel (15);
temp2 = tsc2000_read_channel (15);
if (abs(temp2 - temp1) < MAX_DEVIATION)
offset = temp2;
else {
printf ("%s: read adc value (channel 15) exceeded max allowed "
"deviation: %d * 0.0276 °C\n",
__FUNCTION__, MAX_DEVIATION);
printf ("adc value 1: %ld DIGITs\nadc value 2: %ld DIGITs\n",
temp1, temp2);
offset = tsc2000_read_channel (15);
printf ("use (third read) adc value: offset = %ld DIGITs\n",
offset);
}
debug ("read channel 15 (offset): %ld\n", offset);
/*
* Formula for calculating voltage drop on PT1000 resistor: u_pt1000 =
* x_range3 * (adc_raw - offset) / 10. Formula to calculate x_range3:
* x_range3 = (2500 * (1000000 + err_vref + err_amp3)) / (4095*6). The
* error correction Values err_vref and err_amp3 are assumed as 0 in
* u-boot, because this could cause only a very small error (< 1%).
*/
u_pt1000 = (101750 * (adc_pt1000 - offset)) / 10;
debug ("u_pt1000: %ld\n", u_pt1000);
if (tsc2000_interpolate(u_pt1000, Pt1000_temp_table,
&contact_temp) == -1) {
printf ("%s: error interpolating PT1000 vlaue\n",
__FUNCTION__);
return (-1000);
}
debug ("contact_temp: %ld\n", contact_temp);
return contact_temp;
}
void tsc2000_reg_init (void)
{
struct s3c24x0_gpio * const gpio = s3c24x0_get_base_gpio();
tsc2000_write(TSC2000_REG_ADC, 0x2036);
tsc2000_write(TSC2000_REG_REF, 0x0011);
tsc2000_write(TSC2000_REG_DACCTL, 0x0000);
CON_MUX0;
CON_MUX1;
CON_MUX1_ENABLE;
CON_MUX2_ENABLE;
CON_MUX3_ENABLE;
CON_MUX4_ENABLE;
CON_SEL_TEMP_V_0;
CON_SEL_TEMP_V_1;
CON_SEL_TEMP_V_2;
CON_SEL_TEMP_V_3;
tsc2000_set_mux(0);
tsc2000_set_range(0);
}
int tsc2000_interpolate(long value, long data[][2], long *result)
{
int i;
unsigned long long val;
/* the data is sorted and the first element is upper
* limit so we can easily check for out-of-band values
*/
if (data[0][0] < value || data[1][0] > value)
return -1;
i = 1;
while (data[i][0] < value)
i++;
/* To prevent overflow we have to store the intermediate
result in 'long long'.
*/
val = ((unsigned long long)(data[i][1] - data[i-1][1])
* (unsigned long long)(value - data[i-1][0]));
do_div(val, (data[i][0] - data[i-1][0]));
*result = data[i-1][1] + val;
return 0;
}
void adc_wait_conversion_done(void)
{
while (!(tsc2000_read(TSC2000_REG_ADC) & (1 << 14)));
}