pvt_tt_bh.h

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/*
 * Copyright (c) 2025 Tenstorrent AI ULC
 *
 * SPDX-License-Identifier: Apache-2.0
 */
 
#ifndef PVT_TT_BH_H
#define PVT_TT_BH_H
 
#include <zephyr/drivers/sensor.h>
 
enum pvt_tt_bh_attribute {
        SENSOR_ATTR_PVT_TT_BH_NUM_PD = SENSOR_ATTR_PRIV_START,
        SENSOR_ATTR_PVT_TT_BH_NUM_VM,
        SENSOR_ATTR_PVT_TT_BH_NUM_TS,
};

enum pvt_tt_bh_channel {
        SENSOR_CHAN_PVT_TT_BH_PD = SENSOR_CHAN_PRIV_START,
        SENSOR_CHAN_PVT_TT_BH_VM,
        SENSOR_CHAN_PVT_TT_BH_TS,
        SENSOR_CHAN_PVT_TT_BH_TS_AVG,
};
 
typedef enum {
        ReadOk = 0,
        SampleFault = 1,
        IncorrectSampleType = 2,
        SdifTimeout = 3,
} ReadStatus;
 
struct pvt_tt_bh_config {
        uint8_t num_pd;
        uint8_t num_vm;
        uint8_t num_ts;
 
        /*
         * Single-point calibration delta values for each temperature sensor.
         *
         * During device instantiation (DEFINE_PVT_TT_BH macro), a static array
         * of size num_ts is allocated and zero-initialized for each device instance.
         * The pointer is then set to reference this static array.
         *
         * During pvt_tt_bh_init(), each sensor's 25C calibration value is read from
         * the functional eFuse. The delta between this eFuse value and the expected
         * raw value for 25C is calculated and stored here.
         *
         * To apply calibration: calibrated_reading = raw_reading - therm_cali_delta[sensor_id]
         *
         * Values are in raw sensor units (not celcius). Positive delta means the
         * sensor reads higher than expected, negative means it reads lower.
         *
         * Only populated if the eFuse calibration value is within 3C of 25C
         * (22.0C to 28.0C range). If outside this range, the delta remains 0
         * (no calibration applied).
         *
         * Array allocation: Static array created per device instance via DEFINE_PVT_TT_BH
         * Array size: num_ts elements (from devicetree property)
         * Initialization: Zero-filled during compilation, populated during pvt_tt_bh_init()
         */
        int16_t *therm_cali_delta;
};
 
struct pvt_tt_bh_data {
};
 
/*
 * Raw sensor data that will be submitted to the rtio buffer for the decoder
 * to then use.
 */
struct pvt_tt_bh_rtio_data {
        struct sensor_chan_spec spec;
        uint16_t raw; /* Raw sensor data can fit within 16 bits. */
};
 
/*
 * Convert raw temperature sensor data to celcius.
 */
float pvt_tt_bh_raw_to_temp(uint16_t raw);
 
/*
 * Convert celcius into raw temperature sensor data.
 */
uint16_t pvt_tt_bh_temp_to_raw(const struct sensor_value *value);
 
/*
 * Convert raw voltage monitor data to volts.
 */
float pvt_tt_bh_raw_to_volt(uint16_t raw);
 
/*
 * Convert voltage insto raw voltage monitor data;
 */
uint16_t pvt_tt_bh_volt_to_raw(const struct sensor_value *value);
 
/*
 * Convert raw process detector data to MHz.
 */
float pvt_tt_bh_raw_to_freq(uint16_t raw);
 
/*
 * Convert frequency into raw process detector data.
 */
uint16_t pvt_tt_bh_freq_to_raw(const struct sensor_value *value);
 
/*
 * Represent float data as two integers in struct sensor_value.
 */
void pvt_tt_bh_float_to_sensor_value(float data, struct sensor_value *val);
 
int pvt_tt_bh_get_decoder(const struct device *dev, const struct sensor_decoder_api **api);
 
void pvt_tt_bh_submit(const struct device *sensor, struct rtio_iodev_sqe *sqe);
 
void pvt_tt_bh_delay_chain_set(uint32_t new_delay_chain_);
 
#endif /* PVT_TT_BH_H */