esp-idf/examples/peripherals/touch_element/touch_button/main/CMakeLists.txt

if(IDF_TARGET STREQUAL "esp32s2")
    idf_component_register(SRCS "touch_button_example_main.c"
                        INCLUDE_DIRS ".")
else()
    message(FATAL_ERROR "Touch button example only available on esp32s2 now")
endif()