TIM-VX/include/tim/vx/ops/topk.json

{
    "Topk":{
        "parameters":
            [
                {"name":"k",
                    "dtype": "uint32_t"
                },
                {"name":"axis",
                    "dtype": "uint32_t",
                    "Optional":"true",
                    "default":"0"
                }
            ]
    }
}