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/*
* Copyright © 2012 Keith Packard <keithp@keithp.com>
*
* 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; version 2 of the License.
*
* 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 <ao.h>
#include "ao_ms5607.h"
static struct ms5607_prom ms5607_prom;
static uint8_t ms5607_configured;
static void
ao_ms5607_start(void) {
ao_spi_get(AO_MS5607_SPI_INDEX);
stm_gpio_set(&AO_MS5607_CS_GPIO, AO_MS5607_CS, 0);
}
static void
ao_ms5607_stop(void) {
stm_gpio_set(&AO_MS5607_CS_GPIO, AO_MS5607_CS, 1);
ao_spi_put(AO_MS5607_SPI_INDEX);
}
static void
ao_ms5607_reset(void) {
uint8_t cmd;
cmd = AO_MS5607_RESET;
ao_ms5607_start();
ao_spi_send(&cmd, 1, AO_MS5607_SPI_INDEX);
ao_delay(AO_MS_TO_TICKS(10));
ao_ms5607_stop();
}
static uint8_t
ao_ms5607_crc(uint8_t *prom)
{
uint8_t crc_byte = prom[15];
uint8_t cnt;
uint16_t n_rem = 0;
uint16_t crc_read;
uint8_t n_bit;
prom[15] = 0;
for (cnt = 0; cnt < 16; cnt++) {
n_rem ^= prom[cnt];
for (n_bit = 8; n_bit > 0; n_bit--) {
if (n_rem & 0x8000)
n_rem = (n_rem << 1) ^ 0x3000;
else
n_rem = (n_rem << 1);
}
}
n_rem = (n_rem >> 12) & 0xf;
prom[15] = crc_byte;
return n_rem;
}
static void
ao_ms5607_prom_read(struct ms5607_prom *prom)
{
uint8_t addr;
uint8_t crc;
uint16_t *r;
r = (uint16_t *) prom;
for (addr = 0; addr < 8; addr++) {
uint8_t cmd = AO_MS5607_PROM_READ(addr);
ao_ms5607_start();
ao_spi_send(&cmd, 1, AO_MS5607_SPI_INDEX);
ao_spi_recv(r, 2, AO_MS5607_SPI_INDEX);
ao_ms5607_stop();
r++;
}
crc = ao_ms5607_crc((uint8_t *) prom);
if (crc != (((uint8_t *) prom)[15] & 0xf))
printf ("MS5607 PROM CRC error (computed %x actual %x)\n", crc, (((uint8_t *) prom)[15] & 0xf));
#if __BYTE_ORDER == __LITTLE_ENDIAN
/* Byte swap */
r = (uint16_t *) prom;
for (addr = 0; addr < 8; addr++) {
uint16_t t = *r;
*r++ = (t << 8) | (t >> 8);
}
#endif
}
static void
ao_ms5607_setup(void)
{
if (ms5607_configured)
return;
ms5607_configured = 1;
ao_ms5607_reset();
ao_ms5607_prom_read(&ms5607_prom);
}
static uint32_t
ao_ms5607_convert(uint8_t cmd) {
uint8_t reply[3];
uint8_t read;
ao_ms5607_start();
ao_spi_send(&cmd, 1, AO_MS5607_SPI_INDEX);
ao_ms5607_stop();
ao_delay(AO_MS_TO_TICKS(20));
ao_ms5607_start();
read = AO_MS5607_ADC_READ;
ao_spi_send(&read, 1, AO_MS5607_SPI_INDEX);
ao_spi_recv(&reply, 3, AO_MS5607_SPI_INDEX);
ao_ms5607_stop();
return ((uint32_t) reply[0] << 16) | ((uint32_t) reply[1] << 8) | (uint32_t) reply[2];
}
void
ao_ms5607_sample(struct ao_ms5607_sample *sample)
{
uint8_t addr;
uint32_t D1, D2;
int32_t dT;
int32_t TEMP;
int64_t OFF;
int64_t SENS;
int32_t P;
ao_ms5607_setup();
D2 = ao_ms5607_convert(AO_MS5607_CONVERT_D2_4096);
printf ("Conversion D2: %d\n", D2);
D1 = ao_ms5607_convert(AO_MS5607_CONVERT_D1_4096);
printf ("Conversion D1: %d\n", D1);
dT = D2 - ((int32_t) ms5607_prom.tref << 8);
TEMP = 2000 + (((int64_t) dT * ms5607_prom.tempsens) >> 23);
OFF = ((int64_t) ms5607_prom.off << 17) + (((int64_t) ms5607_prom.tco * dT) >> 6);
SENS = ((int64_t) ms5607_prom.sens << 16) + (((int64_t) ms5607_prom.tcs * dT) >> 7);
if (TEMP < 2000) {
int32_t T2 = ((int64_t) dT * (int64_t) dT) >> 31;
int32_t TEMPM = TEMP - 2000;
int64_t OFF2 = (61 * (int64_t) TEMPM * (int64_t) TEMPM) >> 4;
int64_t SENS2 = 2 * (int64_t) TEMPM * (int64_t) TEMPM;
if (TEMP < 1500) {
int32_t TEMPP = TEMP + 1500;
int64_t TEMPP2 = TEMPP * TEMPP;
OFF2 = OFF2 + 15 * TEMPP2;
SENS2 = SENS2 + 8 * TEMPP2;
}
TEMP -= T2;
OFF -= OFF2;
SENS -= SENS2;
}
P = ((((int64_t) D1 * SENS) >> 21) - OFF) >> 15;
sample->temp = TEMP;
sample->pres = P;
}
static void
ao_ms5607_dump(void)
{
struct ao_ms5607_sample sample;
ao_ms5607_sample(&sample);
printf ("Temperature: %d\n", sample.temp);
printf ("Pressure %d\n", sample.pres);
}
__code struct ao_cmds ao_ms5607_cmds[] = {
{ ao_ms5607_dump, "p\0Display MS5607 data" },
{ 0, NULL },
};
void
ao_ms5607_init(void)
{
ms5607_configured = 0;
ao_cmd_register(&ao_ms5607_cmds[0]);
ao_spi_init_cs(AO_MS5607_CS_GPIO, (1 << AO_MS5607_CS));
}
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