Function esp_wifi_get_protocol 

pub unsafe extern "C" fn esp_wifi_get_protocol(
    ifx: wifi_interface_t,
    protocol_bitmap: *mut u8,
) -> esp_err_t

@brief Get the current protocol bitmap of the specified interface

@attention 1. When WiFi band mode is 2.4G only, it will return the protocol supported in the 2.4G band @attention 2. When WiFi band mode is 5G only, it will return the protocol supported in the 5G band @attention 3. Can not get WiFi protocol under band mode 2.4G + 5G (WIFI_BAND_MODE_AUTO), you can use esp_wifi_get_protocols instead @attention 4. API return ESP_ERR_NOT_SUPPORTED if the band mode is set to 2.4G + 5G (WIFI_BAND_MODE_AUTO)

@param ifx interface @param[out] protocol_bitmap store current WiFi protocol bitmap of interface ifx

@return

• ESP_OK: succeed
• ESP_ERR_WIFI_NOT_INIT: WiFi is not initialized by esp_wifi_init
• ESP_ERR_WIFI_IF: invalid interface
• ESP_ERR_INVALID_ARG: invalid argument
• ESP_ERR_NOT_SUPPORTED: This API is not supported when the band mode is set to 2.4G + 5G (WIFI_BAND_MODE_AUTO)
• others: refer to error codes in esp_err.h