Using MFFI to drive a SureElec LCD display

sureelec.php

<?php
namespace Sureelec;

use MFFI\Library;
use MFFI\Struct;
use MFFI\Type;

class DeviceInfo extends Struct {
    public static function definition() {
        return [
            'width' => Type::TYPE_INT,
            'height' => Type::TYPE_INT,
            'rom_size' => Type::TYPE_INT,
            'has_rx8025' => Type::TYPE_INT,
            'has_light_sensor' => Type::TYPE_INT,
            'has_thermal_sensor' => Type::TYPE_INT,
        ];
    }
}

class Context extends Struct {
    static function definition() {
        return [
            'fd' => Type::TYPE_INT,
            'width' => Type::TYPE_INT,
            'display_info' => DeviceInfo::byValue(),
            'framebuffer' => Type::TYPE_STRING,
            'framebuffer_size' => Type::TYPE_INT,
            'display_state' => Type::TYPE_INT,
            'contrast' => Type::TYPE_INT,
            'brightness' => Type::TYPE_INT
        ];
    }
}

class Display {

    /** @var MFFI\Library */
    protected $library;

    /** @var callable */
    protected $createContext;

    /** @var Sureelec\Context */

    private function createBindings()
    {
        $this->library = new Library('libsureelec.dylib');
        $this->createContext = $this->library->bind('libsureelec_create', 
            [ Type::TYPE_STRING, Type::TYPE_INT ], Context::byReference());
    }

    public function __construct($device, $debug = false) {
        $this->createBindings();
        $this->context = call_user_func($this->createContext, $device, $debug ? 1 : 0);
    }
}

$display = new Display('/dev/tty.SLAB_USBtoUART', true);