zephyr/drivers/sensor/vishay/veml7700/veml7700.c

606 lines
16 KiB
C

/*
* Copyright (c) 2023 Andreas Kilian
* Copyright (c) 2024 Jeff Welder (Ellenby Technologies, Inc.)
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT vishay_veml7700
#include <zephyr/device.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/sensor.h>
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <zephyr/pm/device.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/drivers/sensor/veml7700.h>
LOG_MODULE_REGISTER(VEML7700, CONFIG_SENSOR_LOG_LEVEL);
/*
* Bit mask to zero out all bits except 14 and 15.
* Those two are used for the high and low threshold
* interrupt flags in the ALS_INT register.
*/
#define VEML7700_ALS_INT_MASK (~BIT_MASK(14))
/*
* 16-bit command register addresses
*/
#define VEML7700_CMDCODE_ALS_CONF 0x00
#define VEML7700_CMDCODE_ALS_WH 0x01
#define VEML7700_CMDCODE_ALS_WL 0x02
#define VEML7700_CMDCODE_PSM 0x03
#define VEML7700_CMDCODE_ALS 0x04
#define VEML7700_CMDCODE_WHITE 0x05
#define VEML7700_CMDCODE_ALS_INT 0x06
/*
* Devicetree psm-mode property value for "PSM disabled"
*/
#define VEML7700_PSM_DISABLED 0x00
/*
* ALS integration time setting values.
*
* The enumerators of <tt>enum veml7700_als_it</tt> provide
* indices into this array to get the related value for the
* ALS_IT configuration bits.
*/
static const uint8_t veml7700_it_values[VEML7700_ALS_IT_ELEM_COUNT] = {
0x0C, /* 25 - 0b1100 */
0x08, /* 50 - 0b1000 */
0x00, /* 100 - 0b0000 */
0x01, /* 200 - 0b0001 */
0x02, /* 400 - 0b0010 */
0x03, /* 800 - 0b0011 */
};
/*
* Resolution matrix for values to convert between data provided
* by the sensor ("counts") and lux.
*
* These values depend on the current gain and integration time settings.
* The enumerators of <tt>enum veml7700_als_gain</tt> and <tt>enum veml7700_als_it</tt>
* are used for indices into this matrix.
*/
static const float veml7700_resolution[VEML7700_ALS_GAIN_ELEM_COUNT][VEML7700_ALS_IT_ELEM_COUNT] = {
/* 25ms 50ms 100ms 200ms 400ms 800ms Integration Time */
{0.2304f, 0.1152f, 0.0576f, 0.0288f, 0.0144f, 0.0072f}, /* Gain 1 */
{0.1152f, 0.0576f, 0.0288f, 0.0144f, 0.0072f, 0.0036f}, /* Gain 2 */
{1.8432f, 0.9216f, 0.4608f, 0.2304f, 0.1152f, 0.0576f}, /* Gain 1/8 */
{0.9216f, 0.4608f, 0.2304f, 0.1152f, 0.0576f, 0.0288f}, /* Gain 1/4 */
};
struct veml7700_config {
struct i2c_dt_spec bus;
uint8_t psm;
};
struct veml7700_data {
uint8_t shut_down;
enum veml7700_als_gain gain;
enum veml7700_als_it it;
enum veml7700_int_mode int_mode;
uint16_t thresh_high;
uint16_t thresh_low;
uint16_t als_counts;
uint32_t als_lux;
uint16_t white_counts;
uint32_t int_flags;
};
static bool is_veml7700_gain_in_range(uint32_t gain_selection)
{
return (gain_selection < VEML7700_ALS_GAIN_ELEM_COUNT);
}
static bool is_veml7700_it_in_range(uint32_t it_selection)
{
return (it_selection < VEML7700_ALS_IT_ELEM_COUNT);
}
/**
* @brief Waits for a specific amount of time which depends
* on the current integration time setting.
*
* According to datasheet for a measurement to complete one has
* to wait for at least the integration time. But tests showed
* that a much longer wait time is needed. Simply adding 50 or
* 100ms to the integration time is not enough so we doubled
* the integration time to get our wait time.
*
* This function is only called if the sensor is used in "single shot"
* measuring mode. In this mode the sensor measures on demand an
* measurements take time depending on the configures integration time.
* In continuous mode, activated by one of the power saving modes,
* you can always use the last sample value and no waiting is required.
*
* For more information see the "Designing the VEML7700 Into an Application"
* application notes about the power saving modes.
*/
static void veml7700_sleep_by_integration_time(const struct veml7700_data *data)
{
switch (data->it) {
case VEML7700_ALS_IT_25:
k_msleep(50);
break;
case VEML7700_ALS_IT_50:
k_msleep(100);
break;
case VEML7700_ALS_IT_100:
k_msleep(200);
break;
case VEML7700_ALS_IT_200:
k_msleep(400);
break;
case VEML7700_ALS_IT_400:
k_msleep(800);
break;
case VEML7700_ALS_IT_800:
k_msleep(1600);
break;
}
}
static int veml7700_counts_to_lux(const struct veml7700_data *data, uint16_t counts,
uint32_t *lux)
{
if (!is_veml7700_gain_in_range(data->gain) || !is_veml7700_it_in_range(data->it)) {
return -EINVAL;
}
*lux = counts * veml7700_resolution[data->gain][data->it];
return 0;
}
static int veml7700_lux_to_counts(const struct veml7700_data *data, uint32_t lux,
uint16_t *counts)
{
if (!is_veml7700_gain_in_range(data->gain) || !is_veml7700_it_in_range(data->it)) {
return -EINVAL;
}
*counts = lux / veml7700_resolution[data->gain][data->it];
return 0;
}
static int veml7700_check_gain(const struct sensor_value *val)
{
return val->val1 >= VEML7700_ALS_GAIN_1 && val->val1 <= VEML7700_ALS_GAIN_1_4;
}
static int veml7700_check_it(const struct sensor_value *val)
{
return val->val1 >= VEML7700_ALS_IT_25 && val->val1 <= VEML7700_ALS_IT_800;
}
static int veml7700_check_int_mode(const struct sensor_value *val)
{
return (val->val1 >= VEML7700_ALS_PERS_1 && val->val1 <= VEML7700_ALS_PERS_8) ||
val->val1 == VEML7700_INT_DISABLED;
}
static int veml7700_build_als_conf_param(const struct veml7700_data *data, uint16_t *return_value)
{
if (!is_veml7700_gain_in_range(data->gain) || !is_veml7700_it_in_range(data->it)) {
return -EINVAL;
}
uint16_t param = 0;
/* Bits 15:13 -> reserved */
/* Bits 12:11 -> gain selection (ALS_GAIN) */
param |= data->gain << 11;
/* Bit 10 -> reserved */
/* Bits 9:6 -> integration time (ALS_IT) */
param |= veml7700_it_values[data->it] << 6;
/* Bits 5:4 -> interrupt persistent protection (ALS_PERS) */
if (data->int_mode != VEML7700_INT_DISABLED) {
param |= data->int_mode << 4;
/* Bit 1 -> interrupt enable (ALS_INT_EN) */
param |= BIT(1);
}
/* Bits 3:2 -> reserved */
/* Bit 0 -> shut down setting (ALS_SD) */
if (data->shut_down) {
param |= BIT(0);
}
*return_value = param;
return 0;
}
static uint16_t veml7700_build_psm_param(const struct veml7700_config *conf)
{
/* We can directly use the devicetree configuration value. */
return conf->psm;
}
static int veml7700_write(const struct device *dev, uint8_t cmd, uint16_t data)
{
const struct veml7700_config *conf = dev->config;
uint8_t send_buf[3];
send_buf[0] = cmd; /* byte 0: command code */
sys_put_le16(data, &send_buf[1]); /* bytes 1,2: command arguments */
return i2c_write_dt(&conf->bus, send_buf, ARRAY_SIZE(send_buf));
}
static int veml7700_read(const struct device *dev, uint8_t cmd, uint16_t *data)
{
const struct veml7700_config *conf = dev->config;
uint8_t recv_buf[2];
int ret = i2c_write_read_dt(&conf->bus, &cmd, sizeof(cmd), &recv_buf, ARRAY_SIZE(recv_buf));
if (ret < 0) {
return ret;
}
*data = sys_get_le16(recv_buf);
return 0;
}
static int veml7700_write_als_conf(const struct device *dev)
{
const struct veml7700_data *data = dev->data;
uint16_t param;
int ret = 0;
ret = veml7700_build_als_conf_param(data, &param);
if (ret < 0) {
return ret;
}
LOG_DBG("Writing ALS configuration: 0x%04x", param);
return veml7700_write(dev, VEML7700_CMDCODE_ALS_CONF, param);
}
static int veml7700_write_psm(const struct device *dev)
{
const struct veml7700_config *conf = dev->config;
uint16_t psm_param;
psm_param = veml7700_build_psm_param(conf);
LOG_DBG("Writing PSM configuration: 0x%04x", psm_param);
return veml7700_write(dev, VEML7700_CMDCODE_PSM, psm_param);
}
static int veml7700_write_thresh_low(const struct device *dev)
{
const struct veml7700_data *data = dev->data;
LOG_DBG("Writing low threshold counts: %d", data->thresh_low);
return veml7700_write(dev, VEML7700_CMDCODE_ALS_WL, data->thresh_low);
}
static int veml7700_write_thresh_high(const struct device *dev)
{
const struct veml7700_data *data = dev->data;
LOG_DBG("Writing high threshold counts: %d", data->thresh_high);
return veml7700_write(dev, VEML7700_CMDCODE_ALS_WH, data->thresh_high);
}
static int veml7700_set_shutdown_flag(const struct device *dev, uint8_t new_val)
{
struct veml7700_data *data = dev->data;
uint8_t prev_sd;
int ret;
prev_sd = data->shut_down;
data->shut_down = new_val;
ret = veml7700_write_als_conf(dev);
if (ret < 0) {
data->shut_down = prev_sd;
}
return ret;
}
static int veml7700_fetch_als(const struct device *dev)
{
struct veml7700_data *data = dev->data;
uint16_t counts;
int ret;
ret = veml7700_read(dev, VEML7700_CMDCODE_ALS, &counts);
if (ret < 0) {
return ret;
}
data->als_counts = counts;
ret = veml7700_counts_to_lux(data, counts, &data->als_lux);
if (ret < 0) {
return ret;
}
LOG_DBG("Read ALS measurement: counts=%d, lux=%d", data->als_counts, data->als_lux);
return 0;
}
static int veml7700_fetch_white(const struct device *dev)
{
struct veml7700_data *data = dev->data;
uint16_t counts;
int ret;
ret = veml7700_read(dev, VEML7700_CMDCODE_WHITE, &counts);
if (ret < 0) {
return ret;
}
data->white_counts = counts;
LOG_DBG("Read White Light measurement: counts=%d", data->white_counts);
return 0;
}
static int veml7700_fetch_int_flags(const struct device *dev)
{
struct veml7700_data *data = dev->data;
uint16_t int_flags = 0;
int ret;
ret = veml7700_read(dev, VEML7700_CMDCODE_ALS_INT, &int_flags);
if (ret < 0) {
return ret;
}
data->int_flags = int_flags & VEML7700_ALS_INT_MASK;
LOG_DBG("Read int state: 0x%02x", data->int_flags);
return 0;
}
static int veml7700_attr_set(const struct device *dev, enum sensor_channel chan,
enum sensor_attribute attr, const struct sensor_value *val)
{
if (chan != SENSOR_CHAN_LIGHT) {
return -ENOTSUP;
}
struct veml7700_data *data = dev->data;
int ret = 0;
if (attr == SENSOR_ATTR_LOWER_THRESH) {
ret = veml7700_lux_to_counts(data, val->val1, &data->thresh_low);
if (ret < 0) {
return ret;
}
return veml7700_write_thresh_low(dev);
} else if (attr == SENSOR_ATTR_UPPER_THRESH) {
ret = veml7700_lux_to_counts(data, val->val1, &data->thresh_high);
if (ret < 0) {
return ret;
}
return veml7700_write_thresh_high(dev);
} else if ((enum sensor_attribute_veml7700)attr == SENSOR_ATTR_VEML7700_GAIN) {
if (veml7700_check_gain(val)) {
data->gain = (enum veml7700_als_gain)val->val1;
return veml7700_write_als_conf(dev);
} else {
return -EINVAL;
}
} else if ((enum sensor_attribute_veml7700)attr == SENSOR_ATTR_VEML7700_ITIME) {
if (veml7700_check_it(val)) {
data->it = (enum veml7700_als_it)val->val1;
return veml7700_write_als_conf(dev);
} else {
return -EINVAL;
}
} else if ((enum sensor_attribute_veml7700)attr == SENSOR_ATTR_VEML7700_INT_MODE) {
if (veml7700_check_int_mode(val)) {
data->int_mode = (enum veml7700_int_mode)val->val1;
return veml7700_write_als_conf(dev);
} else {
return -EINVAL;
}
} else {
return -ENOTSUP;
}
}
static int veml7700_attr_get(const struct device *dev, enum sensor_channel chan,
enum sensor_attribute attr, struct sensor_value *val)
{
if (chan != SENSOR_CHAN_LIGHT) {
return -ENOTSUP;
}
struct veml7700_data *data = dev->data;
if (attr == SENSOR_ATTR_LOWER_THRESH) {
val->val1 = data->thresh_low;
} else if (attr == SENSOR_ATTR_UPPER_THRESH) {
val->val1 = data->thresh_high;
} else if ((enum sensor_attribute_veml7700)attr == SENSOR_ATTR_VEML7700_GAIN) {
val->val1 = data->gain;
} else if ((enum sensor_attribute_veml7700)attr == SENSOR_ATTR_VEML7700_ITIME) {
val->val1 = data->it;
} else if ((enum sensor_attribute_veml7700)attr == SENSOR_ATTR_VEML7700_INT_MODE) {
val->val1 = data->int_mode;
} else {
return -ENOTSUP;
}
val->val2 = 0;
return 0;
}
static int veml7700_perform_single_measurement(const struct device *dev)
{
struct veml7700_data *data = dev->data;
int ret;
/* Start sensor */
ret = veml7700_set_shutdown_flag(dev, 0);
if (ret < 0) {
return ret;
}
/* Wait for sensor to finish it's startup sequence */
k_msleep(5);
/* Wait for measurement to complete */
veml7700_sleep_by_integration_time(data);
/* Shut down sensor */
return veml7700_set_shutdown_flag(dev, 1);
}
static int veml7700_sample_fetch(const struct device *dev, enum sensor_channel chan)
{
const struct veml7700_config *conf = dev->config;
struct veml7700_data *data;
int ret;
/* Start sensor for new measurement if power saving mode is disabled */
if ((chan == SENSOR_CHAN_LIGHT || chan == SENSOR_CHAN_ALL) &&
conf->psm == VEML7700_PSM_DISABLED) {
ret = veml7700_perform_single_measurement(dev);
if (ret < 0) {
return ret;
}
}
if (chan == SENSOR_CHAN_LIGHT) {
return veml7700_fetch_als(dev);
} else if ((enum sensor_channel_veml7700)chan == SENSOR_CHAN_VEML7700_INTERRUPT) {
data = dev->data;
if (data->int_mode != VEML7700_INT_DISABLED) {
return veml7700_fetch_int_flags(dev);
} else {
return -ENOTSUP;
}
} else if ((enum sensor_channel_veml7700)chan == SENSOR_CHAN_VEML7700_WHITE_RAW_COUNTS) {
return veml7700_fetch_white(dev);
} else if (chan == SENSOR_CHAN_ALL) {
data = dev->data;
if (data->int_mode != VEML7700_INT_DISABLED) {
ret = veml7700_fetch_int_flags(dev);
if (ret < 0) {
return ret;
}
}
ret = veml7700_fetch_white(dev);
if (ret < 0) {
return ret;
}
return veml7700_fetch_als(dev);
} else {
return -ENOTSUP;
}
}
static int veml7700_channel_get(const struct device *dev, enum sensor_channel chan,
struct sensor_value *val)
{
struct veml7700_data *data = dev->data;
if (chan == SENSOR_CHAN_LIGHT) {
val->val1 = data->als_lux;
} else if ((enum sensor_channel_veml7700)chan == SENSOR_CHAN_VEML7700_RAW_COUNTS) {
val->val1 = data->als_counts;
} else if ((enum sensor_channel_veml7700)chan == SENSOR_CHAN_VEML7700_WHITE_RAW_COUNTS) {
val->val1 = data->white_counts;
} else if ((enum sensor_channel_veml7700)chan == SENSOR_CHAN_VEML7700_INTERRUPT) {
val->val1 = data->int_flags;
} else {
return -ENOTSUP;
}
val->val2 = 0;
return 0;
}
#ifdef CONFIG_PM_DEVICE
static int veml7700_pm_action(const struct device *dev, enum pm_device_action action)
{
const struct veml7700_config *conf = dev->config;
if (conf->psm != VEML7700_PSM_DISABLED) {
switch (action) {
case PM_DEVICE_ACTION_SUSPEND:
return veml7700_set_shutdown_flag(dev, 1);
case PM_DEVICE_ACTION_RESUME:
return veml7700_set_shutdown_flag(dev, 0);
default:
return -ENOTSUP;
}
}
return 0;
}
#endif /* CONFIG_PM_DEVICE */
static int veml7700_init(const struct device *dev)
{
const struct veml7700_config *conf = dev->config;
struct veml7700_data *data = dev->data;
int ret;
if (!i2c_is_ready_dt(&conf->bus)) {
LOG_ERR("Device not ready");
return -ENODEV;
}
/* Initialize power saving mode */
ret = veml7700_write_psm(dev);
if (ret < 0) {
return ret;
}
/* Set initial data values */
data->thresh_low = 0;
data->thresh_high = 0xFFFF;
data->gain = VEML7700_ALS_GAIN_1_4;
data->it = VEML7700_ALS_IT_100;
data->int_mode = VEML7700_INT_DISABLED;
data->als_counts = 0;
data->als_lux = 0;
data->white_counts = 0;
data->shut_down = (conf->psm != VEML7700_PSM_DISABLED) ? 0 : 1;
/* Initialize sensor configuration */
ret = veml7700_write_thresh_low(dev);
if (ret < 0) {
return ret;
}
ret = veml7700_write_thresh_high(dev);
if (ret < 0) {
return ret;
}
ret = veml7700_write_als_conf(dev);
if (ret < 0) {
return ret;
}
return 0;
}
static const struct sensor_driver_api veml7700_api = {.sample_fetch = veml7700_sample_fetch,
.channel_get = veml7700_channel_get,
.attr_set = veml7700_attr_set,
.attr_get = veml7700_attr_get};
#define VEML7700_INIT(n) \
static struct veml7700_data veml7700_data_##n; \
\
static const struct veml7700_config veml7700_config_##n = { \
.bus = I2C_DT_SPEC_INST_GET(n), .psm = DT_INST_PROP(n, psm_mode)}; \
\
PM_DEVICE_DT_INST_DEFINE(n, veml7700_pm_action); \
\
SENSOR_DEVICE_DT_INST_DEFINE(n, veml7700_init, PM_DEVICE_DT_INST_GET(n), \
&veml7700_data_##n, &veml7700_config_##n, POST_KERNEL, \
CONFIG_SENSOR_INIT_PRIORITY, &veml7700_api);
DT_INST_FOREACH_STATUS_OKAY(VEML7700_INIT)