#include <sys/stat.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <linux/avm_i2c.h>
#include <errno.h>
#include "avm_i2c.h"

/*------------------------------------------------------------------------------------------*\
\*------------------------------------------------------------------------------------------*/
struct _avm_i2c_open_data {
    int fd;
    enum _avm_i2c_type device_type;
};

/*------------------------------------------------------------------------------------------*\
\*------------------------------------------------------------------------------------------*/
void *avm_i2c_open(enum _avm_i2c_type device_type) {
    const char *filename = "/dev/i2c";
    struct _avm_i2c_open_data *open_data = calloc(sizeof(struct _avm_i2c_open_data), 1);;
    if(open_data == NULL)
        return NULL;
    if ((open_data->fd = open(filename, O_RDWR)) < 0) {
        free(open_data);
        return NULL;
    }
    open_data->device_type = device_type;
    return (void *)open_data;
}

/*------------------------------------------------------------------------------------------*\
\*------------------------------------------------------------------------------------------*/
int avm_i2c_close(void *handle) {
    struct _avm_i2c_open_data *open_data = (struct _avm_i2c_open_data *)handle;
    if(open_data == NULL)
        return 1;
    close(open_data->fd);
    free(open_data);
    return 0;
}

/*------------------------------------------------------------------------------------------*\
\*------------------------------------------------------------------------------------------*/
int avm_i2c_speed(void *handle, int speed) {
    struct _i2c_cmd Cmd;
    struct _avm_i2c_open_data *open_data = (struct _avm_i2c_open_data *)handle;
    if(open_data == NULL)
        return 1;

    *((unsigned int *)Cmd.Buffer) = speed;
    if (ioctl(open_data->fd, I2C_SET_SPEED_ID, &Cmd) < 0) {
        return 1;
    }
    return 0;
}

/*------------------------------------------------------------------------------------------*\
\*------------------------------------------------------------------------------------------*/
int avm_i2c_read(void *handle, int device_addr, int register_addr, unsigned char *Buffer, int len) {
    struct _i2c_cmd Cmd;
    struct _avm_i2c_open_data *open_data = (struct _avm_i2c_open_data *)handle;
    if(open_data == NULL)
        return 1;

    Cmd.device_address   = device_addr;
    Cmd.register_address = register_addr;
    Cmd.data_length      = len;
    Cmd.device_type      = open_data->device_type;
    if (ioctl(open_data->fd, I2C_READ_ID, &Cmd) < 0) {
        return -errno;
    }
    memcpy(Buffer, Cmd.Buffer, Cmd.data_length);
    return len;
}

/*------------------------------------------------------------------------------------------*\
\*------------------------------------------------------------------------------------------*/
int avm_i2c_write(void *handle, int device_addr, int register_addr, unsigned char *Buffer, int len) {
    struct _i2c_cmd Cmd;
    struct _avm_i2c_open_data *open_data = (struct _avm_i2c_open_data *)handle;
    if(open_data == NULL)
        return 1;

    Cmd.device_address   = device_addr;
    Cmd.register_address = register_addr;
    Cmd.data_length      = len;
    Cmd.device_type      = open_data->device_type;
    memcpy(Cmd.Buffer, Buffer, Cmd.data_length);
    if (ioctl(open_data->fd, I2C_WRITE_ID, &Cmd) < 0) {
        return -errno;
    }
    return len;
}

/*------------------------------------------------------------------------------------------*\
\*------------------------------------------------------------------------------------------*/
int avm_i2c_raw_read(void *handle, int device_addr, unsigned char *Buffer, int len) {
    struct _i2c_cmd Cmd;
    struct _avm_i2c_open_data *open_data = (struct _avm_i2c_open_data *)handle;
    if(open_data == NULL)
        return 1;

    Cmd.device_address   = device_addr;
    Cmd.data_length      = len;
    Cmd.device_type      = open_data->device_type;
    if (ioctl(open_data->fd, I2C_RAW_READ_ID, &Cmd) < 0) {
        return -errno;
    }
    memcpy(Buffer, Cmd.Buffer, Cmd.data_length);
    return len;
}

/*------------------------------------------------------------------------------------------*\
\*------------------------------------------------------------------------------------------*/
int avm_i2c_raw_write(void *handle, int device_addr, unsigned char *Buffer, int len) {
    struct _i2c_cmd Cmd;
    struct _avm_i2c_open_data *open_data = (struct _avm_i2c_open_data *)handle;
    if(open_data == NULL)
        return 1;

    Cmd.device_address   = device_addr;
    Cmd.data_length      = len;
    Cmd.device_type      = open_data->device_type;
    memcpy(Cmd.Buffer, Buffer, Cmd.data_length);
    if (ioctl(open_data->fd, I2C_RAW_WRITE_ID, &Cmd) < 0) {
        return -errno;
    }
    return len;
}