#ifndef __INA226_H__
#define __INA226_H__

#include <stdint.h>
#include <stdbool.h>
#include <limits.h>
#include "i2c.h"

/* Fixed values from datasheet */
#define INA226_VB_LSB_uV 1250
#define INA226_VS_LSB_nV 2500

enum ina226_reg {
    INA226_REG_CONFIG   = 0x00,
    INA226_REG_VS       = 0x01,
    INA226_REG_VB       = 0x02,
    INA226_REG_P        = 0x03,
    INA226_REG_I        = 0x04,
    INA226_REG_CAL      = 0x05,
    INA226_REG_MASK_EN  = 0x06,
    INA226_REG_ALERT    = 0x07,
    INA226_REG_MFGID    = 0xfe,
    INA226_REG_DIEID    = 0xff
};

enum ina226_config {
    INA226_CONFIG_RST = 1<<15,

    INA226_CONFIG_AVG_Pos   = 9,
    INA226_CONFIG_AVG_Msk   = 3<<9,
    INA226_CONFIG_AVG_1     = 0<<9,
    INA226_CONFIG_AVG_4     = 1<<9,
    INA226_CONFIG_AVG_16    = 2<<9,
    INA226_CONFIG_AVG_64    = 3<<9,
    INA226_CONFIG_AVG_128   = 4<<9,
    INA226_CONFIG_AVG_256   = 5<<9,
    INA226_CONFIG_AVG_512   = 6<<9,
    INA226_CONFIG_AVG_1024  = 7<<9,

    INA226_CONFIG_VBUSCT_Pos    = 6,
    INA226_CONFIG_VBUSCT_Msk    = 7<<6,
    INA226_CONFIG_VBUSCT_140u   = 0<<6,
    INA226_CONFIG_VBUSCT_204u   = 1<<6,
    INA226_CONFIG_VBUSCT_332u   = 2<<6,
    INA226_CONFIG_VBUSCT_588u   = 3<<6,
    INA226_CONFIG_VBUSCT_1m1    = 4<<6,
    INA226_CONFIG_VBUSCT_2m116  = 5<<6,
    INA226_CONFIG_VBUSCT_4m156  = 6<<6,
    INA226_CONFIG_VBUSCT_8m244  = 7<<6,

    INA226_CONFIG_VSHCT_Pos     = 3,
    INA226_CONFIG_VSHCT_Msk     = 7<<3,
    INA226_CONFIG_VSHCT_140u    = 0<<3,
    INA226_CONFIG_VSHCT_204u    = 1<<3,
    INA226_CONFIG_VSHCT_332u    = 2<<3,
    INA226_CONFIG_VSHCT_588u    = 3<<3,
    INA226_CONFIG_VSHCT_1m1     = 4<<3,
    INA226_CONFIG_VSHCT_2m116   = 5<<3,
    INA226_CONFIG_VSHCT_4m156   = 6<<3,
    INA226_CONFIG_VSHCT_8m244   = 7<<3,

    INA226_CONFIG_MODE_Pos          = 0,
    INA226_CONFIG_MODE_Msk          = 7,
    INA226_CONFIG_MODE_POWERDOWN    = 0,

    INA226_CONFIG_MODE_SHUNT        = 1,

    INA226_CONFIG_MODE_BUS          = 2,

    INA226_CONFIG_MODE_TRIG         = 0,
    INA226_CONFIG_MODE_CONT         = 4
};

enum ina226_mask_en {
    INA226_MASK_EN_SOL  = 1<<15,
    INA226_MASK_EN_SUL  = 1<<14,
    INA226_MASK_EN_BOL  = 1<<13,
    INA226_MASK_EN_BUL  = 1<<12,
    INA226_MASK_EN_POL  = 1<<11,
    INA226_MASK_EN_CNVR = 1<<10,
    INA226_MASK_EN_AFF  = 1<<4,
    INA226_MASK_EN_CVRF = 1<<3,
    INA226_MASK_EN_OVF  = 1<<2,
    INA226_MASK_EN_APOL = 1<<1,
    INA226_MASK_EN_LEN  = 1<<0
};

struct ina226 {
    I2C_TypeDef *i2c_periph;
    uint8_t i2c_addr;
    uint16_t rs_uOhm;
    uint16_t conv_config;
    uint16_t i_lsb_uA;
    bool conv_ready:1;
};

/* High-level API */
void ina226_init(struct ina226 *dev, I2C_TypeDef *i2c_periph, uint8_t i2c_addr, uint16_t rs_uOhm, uint16_t conv_config);
void ina226_trigger(struct ina226 *dev, int mode);
bool ina226_conv_ready(struct ina226 *dev);
int ina226_read_raw(struct ina226 *dev, int16_t *I_raw, int16_t *V_raw, int16_t *Vs_raw);
int ina226_read_scaled(struct ina226 *dev, int16_t *I_mA, int16_t *V_mV, int16_t *Vs_uV);

/* Low-level API */
void ina226_write_reg(struct ina226 *dev, uint8_t reg, uint16_t val);
uint16_t ina226_read_reg(struct ina226 *dev, uint8_t reg);

#endif /* __INA226_H__ */