[feat] add is_link_up

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "e1000-driver"
 authors = ["Luoyuan Xiao <[email protected]>", "Zhou Rui <[email protected]>"]
-version = "0.2.2"
+version = "0.2.3"
 edition = "2018"
 license = "GPL-2.0"
 repository = "https://github.com/elliott10/e1000-driver.git"

src/e1000/e1000.rs

@@ -154,7 +154,9 @@ impl E1000 {
 
         Ok(())
     }
-
+    pub fn is_link_up(&self) -> bool {
+        self.is_link_up.load(Ordering::SeqCst)
+    }
     pub fn down(&mut self) {
         /* disable transmits in the hardware */
         let mut tctl = self.er32(TCTL);