Below is the code for getting the hardware string, but you need to compare these hardware string to know which device it is. I have created a class for that contains almost all the device strings(we're keeping string upto date with new devices). It's easy to use please check
Swift : GitHub/DeviceGuru
Objective-C : GitHub/DeviceUtil
public func hardwareString() -> String {
var name: [Int32] = [CTL_HW, HW_MACHINE]
var size: Int = 2
sysctl(&name, 2, nil, &size, &name, 0)
var hw_machine = [CChar](count: Int(size), repeatedValue: 0)
sysctl(&name, 2, &hw_machine, &size, &name, 0)
let hardware: String = String.fromCString(hw_machine)!
return hardware
}