Add wifi_set_mode for Wifi Protocol Support (esp-rs#156)

* Add set_mode

* Revert unnecessary changes

* Review changes

* Removed unecessary change

* Review changes, merge conflict fix

esp-wifi/build.rs

@@ -18,8 +18,6 @@ fn main() -> Result<(), String> {
                 .to_string();
                 println!("cargo:warning={}", message);
             }
-
-            ()
         }
         Err(_err) => (),
     }

esp-wifi/src/wifi/mod.rs

@@ -7,7 +7,7 @@ use crate::common_adapter::*;
 
 use crate::esp_wifi_result;
 use critical_section::Mutex;
-use embedded_svc::wifi::{AccessPointInfo, AuthMethod, SecondaryChannel};
+use embedded_svc::wifi::{AccessPointInfo, AuthMethod, Protocol, SecondaryChannel};
 use enumset::EnumSet;
 use enumset::EnumSetType;
 use esp_hal_common::peripheral::Peripheral;
@@ -29,6 +29,7 @@ use esp_wifi_sys::include::wifi_interface_t_WIFI_IF_AP;
 use esp_wifi_sys::include::wifi_mode_t_WIFI_MODE_AP;
 use esp_wifi_sys::include::wifi_mode_t_WIFI_MODE_APSTA;
 use esp_wifi_sys::include::wifi_mode_t_WIFI_MODE_NULL;
+use esp_wifi_sys::include::esp_wifi_set_protocol;
 use num_derive::FromPrimitive;
 use num_traits::FromPrimitive;
 
@@ -752,6 +753,25 @@ impl<'d> WifiController<'d> {
         Self { _device, config }
     }
 
+    /// Set the wifi mode.
+    /// This will set the wifi protocol to the desired protocol, the default for this is:
+    /// `WIFI_PROTOCOL_11B|WIFI_PROTOCOL_11G|WIFI_PROTOCOL_11N`
+    /// # Arguments:
+    /// * `protocol` - The desired protocol
+    /// # Example:
+    /// ```
+    /// use embedded_svc::wifi::Protocol;
+    /// use esp_wifi::wifi::WifiController;
+    /// let mut wifi = WifiController::new();
+    /// wifi.set_mode(Protocol::P802D11BGNLR);
+    /// ```
+    pub fn set_mode(&mut self, protocol: Protocol) -> Result<(), WifiError> {
+        let mut mode = wifi_mode_t_WIFI_MODE_NULL;
+        esp_wifi_result!(unsafe { esp_wifi_get_mode(&mut mode) })?;
+        esp_wifi_result!(unsafe { esp_wifi_set_protocol(mode, protocol as u8) })?;
+        Ok(())
+    }
+
     fn is_sta_enabled(&self) -> Result<bool, WifiError> {
         let mut mode: esp_wifi_sys::include::wifi_mode_t = 0;
         esp_wifi_result!(unsafe { esp_wifi_sys::include::esp_wifi_get_mode(&mut mode) })?;