board/trab/tsc2000.c - platform/external/u-boot - Gitiles

 /*
  * 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)));
 }
	/*
	* 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)));
	}