hybridgroup.gobot/sysfs/i2c_device.go

package sysfs

import (
	"fmt"
	"io"
	"os"
	"syscall"
)

// I2CSlave is the linux default ioctrl request code
const I2CSlave = 0x0703

// NewI2cDevice returns an io.ReadWriteCloser with the proper ioctrl given
// an i2c bus location and device address
func NewI2cDevice(location string, address byte) (io.ReadWriteCloser, error) {
	file, err := OpenFile(location, os.O_RDWR, os.ModeExclusive)

	if err != nil {
		return nil, err
	}

	_, _, errno := Syscall(
		syscall.SYS_IOCTL,
		file.Fd(),
		I2CSlave,
		uintptr(address),
	)

	if errno != 0 {
		return nil, fmt.Errorf("Failed with syscall.Errno %v", errno)
	}

	return file, nil
}