Convert hexadecimal Byte to integer using C program

/*C program to convert hexadecimal Byte to integer.*/

#include <stdio.h>

//function : getNum
//this function will return number corresponding
//0,1,2..,9,A,B,C,D,E,F

int getNum(char ch)
{
    int num = 0;
    if (ch >= '0' && ch <= '9') {
        num = ch - 0x30;
    }
    else {
        switch (ch) {
        case 'A':
        case 'a':
            num = 10;
            break;
        case 'B':
        case 'b':
            num = 11;
            break;
        case 'C':
        case 'c':
            num = 12;
            break;
        case 'D':
        case 'd':
            num = 13;
            break;
        case 'E':
        case 'e':
            num = 14;
            break;
        case 'F':
        case 'f':
            num = 15;
            break;
        default:
            num = 0;
        }
    }
    return num;
}

//function : hex2int
//this function will return integer value against
//hexValue - which is in string format

unsigned int hex2int(unsigned char hex[])
{
    unsigned int x = 0;
    x = (getNum(hex[0])) * 16 + (getNum(hex[1]));
}

int main()
{
    unsigned char hexValue[2] = "9A";
    unsigned int intValue = 0; //can be stored in unsigned char

    intValue = hex2int(hexValue);

    printf("value is: %d\n", intValue);

    return 0;
}

Output:

    
    value is: 154