choice XTAL_FREQ
    prompt "Main XTAL frequency"
    default XTAL_FREQ_40
    help
        This option selects the operating frequency of the XTAL (crystal) clock used to drive the ESP target.
        The selected value MUST reflect the frequency of the given hardware.

        Note: On ESP32, the XTAL_FREQ_AUTO option allows the ESP target to automatically estimating XTAL clock's
        operating frequency. The ESP32 uses the internal 8MHZ as a reference when estimating. Due to the internal
        oscillator's frequency being temperature dependent, usage of the XTAL_FREQ_AUTO is not recommended in
        applications that operate in high ambient temperatures or use high-temperature qualified chips and modules.

    config XTAL_FREQ_26
        bool "26 MHz"
    config XTAL_FREQ_32
        bool "32 MHz"
    config XTAL_FREQ_40
        bool "40 MHz"
    config XTAL_FREQ_AUTO
        bool "Autodetect"
endchoice

# soc_xtal_freq_t enum in soc/clk_tree_defs.h lists the XTAL frequencies can be supported
# SOC_XTAL_SUPPORT_XXX in soc_caps.h lists the XTAL frequencies already supported
config XTAL_FREQ
    int
    default 26 if XTAL_FREQ_26
    default 32 if XTAL_FREQ_32
    default 40 if XTAL_FREQ_40
    default 0  if XTAL_FREQ_AUTO