zephyr/drivers/sensor/tcn75a/tcn75a.h

84 lines
2.5 KiB
C

/*
* Copyright 2023 Daniel DeGrasse <daniel@degrasse.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef _DRIVERS_SENSOR_TCN75A_H_
#define _DRIVERS_SENSOR_TCN75A_H_
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/sensor.h>
#include <zephyr/sys/byteorder.h>
#define TCN75A_TEMP_REG 0x0
#define TCN75A_CONFIG_REG 0x1
#define TCN75A_THYST_REG 0x2
#define TCN75A_TSET_REG 0x3
/* TCN75A TEMP register constants */
#define TCN75A_TEMP_MSB_POS 8
#define TCN75A_TEMP_MSB_MASK 0xFF00
#define TCN75A_TEMP_LSB_MASK 0xFF
#define TCN75A_TEMP_LSB_POS 0
/* TCN75A CONFIG register constants */
#define TCN75A_CONFIG_ONEDOWN BIT(7)
#define TCN75A_CONFIG_RES(x) (((x) & 0x3) << 5)
#define TCN75A_CONFIG_INT_EN 0x2
#define TCN75A_CONFIG_SHUTDOWN 0x1
struct tcn75a_config {
struct i2c_dt_spec i2c_spec;
bool oneshot_mode;
uint8_t resolution;
#ifdef CONFIG_TCN75A_TRIGGER
struct gpio_dt_spec alert_gpios;
#endif
};
struct tcn75a_data {
uint16_t temp_sample;
#ifdef CONFIG_TCN75A_TRIGGER
const struct device *dev;
struct gpio_callback gpio_cb;
sensor_trigger_handler_t sensor_cb;
const struct sensor_trigger *sensor_trig;
#endif
#ifdef CONFIG_TCN75A_TRIGGER_GLOBAL_THREAD
struct k_work work;
#endif
#ifdef CONFIG_TCN75A_TRIGGER_OWN_THREAD
K_KERNEL_STACK_MEMBER(thread_stack, CONFIG_TCN75A_THREAD_STACK_SIZE);
struct k_thread thread;
struct k_sem trig_sem;
#endif
};
/* Helpers to convert from TCN75A temperature fixed point format
* to sensor val2 format. When the LSB of the TCN75A temperature sample
* is treated as an integer, the format to convert to sensor val2 is
* FIXED_POINT_VAL * 3906.25
*/
#define TCN75A_FIXED_PT_TO_SENSOR(x) (((x)*3906) + ((x) >> 2))
/* This conversion is imprecise, but because the 4 least significant bits
* of the temperature register aren't used, it doesn't matter.
*/
#define TCN75A_SENSOR_TO_FIXED_PT(x) ((x) / 3906)
#ifdef CONFIG_TCN75A_TRIGGER
int tcn75a_trigger_init(const struct device *dev);
int tcn75a_attr_get(const struct device *dev, enum sensor_channel chan, enum sensor_attribute attr,
struct sensor_value *val);
int tcn75a_attr_set(const struct device *dev, enum sensor_channel chan, enum sensor_attribute attr,
const struct sensor_value *val);
int tcn75a_trigger_set(const struct device *dev, const struct sensor_trigger *trig,
sensor_trigger_handler_t handler);
#endif
int tcn75a_sample_fetch(const struct device *dev, enum sensor_channel chan);
#endif /* _DRIVERS_SENSOR_TCN75A_H_ */