// common.c
#include <stdlib.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#include "common.h"
#include "i2c_linux.h"

/* Default Linux I2C bus and BME68x address (low = 0x76) :contentReference[oaicite:2]{index=2} */
#define DEFAULT_I2C_BUS       "/dev/i2c-1"
#define DEFAULT_BME68X_ADDR   BME68X_I2C_ADDR_LOW

int8_t bme68x_interface_init(struct bme68x_dev *bme, uint8_t intf)
{
    if (intf != BME68X_I2C_INTF) {
        return BME68X_E_INVALID_LENGTH;
    }
    // allocate space for our file-descriptor
    int *fd = malloc(sizeof(int));
    if (!fd) {
        return BME68X_E_NULL_PTR;
    }
    *fd = i2c_open_bus(DEFAULT_I2C_BUS);
    if (*fd < 0) {
        free(fd);
        return BME68X_E_COM_FAIL;
    }
    // tell the driver which slave address to use
    if (ioctl(*fd, I2C_SLAVE, BME68X_I2C_ADDR_HIGH) < 0) {
        perror("Failed to set I2C_SLAVE");
        i2c_close_bus(*fd);
        free(fd);
        return BME68X_E_COM_FAIL;
    }
    bme->intf_ptr = fd;
    bme->read     = bme68x_i2c_read;
    bme->write    = bme68x_i2c_write;
    bme->delay_us = bme68x_delay_us;
    bme->intf     = BME68X_I2C_INTF;
    return BME68X_OK;
}

void bme68x_interface_deinit(struct bme68x_dev *bme)
{
    if (bme->intf_ptr) {
        int fd = *(int *)bme->intf_ptr;
        i2c_close_bus(fd);
        free(bme->intf_ptr);
        bme->intf_ptr = NULL;
    }
}