i2c and rust

humbug.rs

use std::io::Write;
use std::os::unix::io::AsRawFd;
use std::fs::OpenOptions;

extern crate libc;
fn main() {
    const I2C_SLAVE: u64 = 0x0703;
    const DEVICE: u32 = 0x2a;
    const I2C_DATA: [u8;2] = [0x2a, 0x2a];
    let mut file = OpenOptions::new().read(false).write(true).create(false).open("/dev/i2c-1").expect("File not found?");
    unsafe {
        let is_i2cslave: i32 = libc::ioctl(file.as_raw_fd(), I2C_SLAVE, DEVICE);
        println!("Return value: {}", is_i2cslave);
        if is_i2cslave > 0 {
            println!("Writing magic numbers...");
            file.write_all(&I2C_DATA).expect("Failed to write magic sequence");
        }
    }
}