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RIOT/drivers/tsl4531x/tsl4531x.c
2021-11-29 06:35:25 +01:00

217 lines
6.0 KiB
C

/*
* Copyright (C) 2016 Inria
* Copyright (C) 2018 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup drivers_tsl4531x
* @{
*
* @file
* @brief Device driver for the TSL4531x Luminosity sensor.
*
* @author Daniel Petry <daniel.petry@fu-berlin.de>
* @author Juan I Carrano <j.carrano@fu-berlin.de>
* @author Alexandre Abadie <alexandre.abadie@inria.fr>
*
* This driver was derived from the TSL2561 driver.
*
* @}
*/
#include <assert.h>
#include <errno.h>
#include "log.h"
#include "tsl4531x.h"
#include "tsl4531x_internals.h"
#include "xtimer.h"
#define ENABLE_DEBUG 0
#include "debug.h"
#define _DATALOW 0
#define _DATAHIGH 1
int tsl4531x_init(tsl4531x_t *dev, const tsl4531x_params_t *params)
{
int r;
uint8_t id;
/* Initialise I2C bus */
i2c_acquire(params->i2c_dev);
/* Test for connectivity - verify ID and compare against stored value */
if ((r = i2c_read_reg(params->i2c_dev,
params->i2c_addr,
TSL4531X_COMMAND(TSL4531X_ID_REG),
&id, 0)) < 0) {
DEBUG("[Error] Cannot read ID register. I2C error: %d\n", r);
i2c_release(params->i2c_dev);
return -ENXIO;
}
DEBUG("[Info] tsl4531x sensor ID ? %d\n", id);
if (TSL4531X_GET_PARTNO(id) != params->part_number) {
DEBUG("[Error] not a TSL4531 sensor.\n");
i2c_release(params->i2c_dev);
return -ENOTSUP;
}
/* Configure device. In low power mode, we initially power the sensor down. */
if (((r = i2c_write_reg(params->i2c_dev,
params->i2c_addr,
TSL4531X_COMMAND(TSL4531X_CONTROL_REG),
TSL4531X_CONTROL(TSL4531X_POWER_MODE(params->low_power_mode)),
0)) < 0)
||
((r = i2c_write_reg(params->i2c_dev,
params->i2c_addr,
TSL4531X_COMMAND(TSL4531X_CONFIGURATION_REG),
TSL4531X_CONFIG(TSL4531X_PSAVESKIP_ON, params->integration_time),
0)) < 0)) {
DEBUG("[Error] Cannot configure device. I2C error: %d\n", r);
i2c_release(params->i2c_dev);
return -ENXIO;
}
/* If device was configured correctly, initialise the device descriptor */
dev->i2c_dev = params->i2c_dev;
dev->i2c_addr = params->i2c_addr;
dev->integration_time = params->integration_time;
dev->low_power_mode = params->low_power_mode;
dev->high_power_mode_started_up = false;
dev->sample_start_time = 0; /* Device assumed to start up at same time as
microcontroller - i.e. when it hits this line */
i2c_release(params->i2c_dev);
return 0;
}
int tsl4531x_set_low_power_mode(tsl4531x_t *dev, uint8_t low_power_mode)
{
assert(dev);
int r;
dev->low_power_mode = low_power_mode;
i2c_acquire(dev->i2c_dev);
if ((r = i2c_write_reg(dev->i2c_dev,
dev->i2c_addr,
TSL4531X_COMMAND(TSL4531X_CONTROL_REG),
TSL4531X_CONTROL(TSL4531X_POWER_MODE(low_power_mode)),
0)) < 0) {
DEBUG("[Error] Cannot write power mode. I2C error: %d\n", r);
i2c_release(dev->i2c_dev);
return -ENXIO;
}
i2c_release(dev->i2c_dev);
/* In high power mode only, we restart the sample ready timer, because only
in this mode it's used to indicate readiness after startup. */
if (!dev->low_power_mode) {
dev->sample_start_time = xtimer_now_usec();
}
return 0;
}
int tsl4531x_start_sample(tsl4531x_t *dev)
{
assert(dev);
/* Don't change the mode to one-shot if the device is in high power mode. */
if (dev->low_power_mode) {
int r;
i2c_acquire(dev->i2c_dev);
if ((r = i2c_write_reg(dev->i2c_dev,
dev->i2c_addr,
TSL4531X_COMMAND(TSL4531X_CONTROL_REG),
TSL4531X_CONTROL(TSL4531X_MODE_SINGLE_ADC_CYCLE),
0)) < 0) {
DEBUG("[Error] Cannot write power mode. I2C error: %d\n", r);
i2c_release(dev->i2c_dev);
return -ENXIO;
}
i2c_release(dev->i2c_dev);
dev->sample_start_time = xtimer_now_usec();
}
return 0;
}
uint32_t tsl4531x_time_until_sample_ready(tsl4531x_t *dev)
{
assert(dev);
uint32_t t = TSL4531X_GET_INTEGRATION_TIME_USEC(dev->integration_time, TSL4531X_PSAVESKIP_ON) -
(xtimer_now_usec() - dev->sample_start_time);
/* Clamp t at zero */
t = (t <= TSL4531X_GET_INTEGRATION_TIME_USEC(dev->integration_time, TSL4531X_PSAVESKIP_ON) ?
t : 0);
if (!dev->low_power_mode) {
if (t == 0) {
dev->high_power_mode_started_up = true;
}
if (dev->high_power_mode_started_up) {
return 0;
}
}
return t;
}
int tsl4531x_get_sample(const tsl4531x_t *dev)
{
assert(dev);
int r;
uint8_t als_data[2]; /* = {[DATALOW], [DATAHIGH]} */
i2c_acquire(dev->i2c_dev);
if ((r = i2c_read_regs(dev->i2c_dev,
dev->i2c_addr,
TSL4531X_COMMAND(TSL4531X_ALSDATA1_REG),
als_data, 2, 0)) < 0) {
DEBUG("[Error] Cannot read data register. I2C error: %d\n", r);
i2c_release(dev->i2c_dev);
return -ENXIO;
}
i2c_release(dev->i2c_dev);
return MULTIPLY_DATA((((uint16_t)als_data[_DATAHIGH]) << 8)
+ als_data[_DATALOW], dev->integration_time);
}
int tsl4531x_simple_read(tsl4531x_t *dev)
{
assert(dev);
if (dev->low_power_mode) {
tsl4531x_start_sample(dev);
}
xtimer_usleep(tsl4531x_time_until_sample_ready(dev));
return tsl4531x_get_sample(dev);
}