Function esp_wifi_set_protocol 

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

@brief Set protocol type of specified interface The default protocol is (WIFI_PROTOCOL_11B|WIFI_PROTOCOL_11G|WIFI_PROTOCOL_11N). if CONFIG_SOC_WIFI_HE_SUPPORT and band mode is 2.4G, the default protocol is (WIFI_PROTOCOL_11B|WIFI_PROTOCOL_11G|WIFI_PROTOCOL_11N|WIFI_PROTOCOL_11AX). if CONFIG_SOC_WIFI_SUPPORT_5G and band mode is 5G, the default protocol is (WIFI_PROTOCOL_11A|WIFI_PROTOCOL_11N|WIFI_PROTOCOL_11AC|WIFI_PROTOCOL_11AX).

@attention 1. When WiFi band mode is 2.4G only, support 802.11b or 802.11bg or 802.11bgn or 802.11bgnax or LR mode @attention 2. When WiFi band mode is 5G only, support 802.11a or 802.11an or 802.11anac or 802.11anacax @attention 3. Can not set WiFi protocol under band mode 2.4G + 5G (WIFI_BAND_MODE_AUTO), you can use esp_wifi_set_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 protocol_bitmap WiFi protocol bitmap

@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