diff options
Diffstat (limited to 'u-boot/board/trab/tsc2000.c')
| -rw-r--r-- | u-boot/board/trab/tsc2000.c | 366 |
1 files changed, 366 insertions, 0 deletions
diff --git a/u-boot/board/trab/tsc2000.c b/u-boot/board/trab/tsc2000.c new file mode 100644 index 0000000..426ed9c --- /dev/null +++ b/u-boot/board/trab/tsc2000.c @@ -0,0 +1,366 @@ +/* + * 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 <asm/arch/s3c24x0_cpu.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))); +} |