feat(serial): add serial initialization

Signed-off-by: Julien CLEMENT <julien.clement@epita.fr>

src/serial.rs

@@ -11,8 +11,18 @@ const COM3: u16 = 0x3e8;
 #[allow(dead_code)]
 const COM4: u16 = 0x2e8;
 
+const ENABLE_TRANSMITTER: u8 = 0x1 << 1;
+
+const FIFO: u8 = 0x1;
+const TRIGGER_LVL_14: u8 = 0x3 << 6;
+const CLEAR_TRANSMIT_FIFO: u8 = 0x1 << 2;
+const CLEAR_REVEIVE_FIFO: u8 = 0x1 << 1;
+
+const NO_PARITY: u8 = 0x0;
+const EIGHT_BITS_LENGTH: u8 = 0x3;
 
 const EMPTY_TRANSMITTER: u8 = 0x1 << 5;
+const DLAB: u8 = 0x1 << 7;
 
 lazy_static! {
     pub static ref SERIAL1: Mutex<SerialPort> = {
@@ -50,6 +60,9 @@ macro_rules! serial_println {
 
 pub struct SerialPort {
     base: Port<u8>,
+    interrupt_enable: Port<u8>,
+    fifo_control: Port<u8>,
+    line_control: Port<u8>,
     line_status: Port<u8>,
 }
 
@@ -57,6 +70,9 @@ impl SerialPort {
     pub fn new(port: u16) -> SerialPort {
         SerialPort {
             base: Port::new(port),
+            interrupt_enable: Port::new(port + 1),
+            fifo_control: Port::new(port + 2),
+            line_control: Port::new(port + 3),
             line_status: Port::new(port + 5),
         }
     }
@@ -86,7 +102,26 @@ impl SerialPort {
         len
     }
 
-    fn init(&mut self) {}
+    fn init_baud_rate(&mut self) {
+        let line: u8;
+        unsafe {
+            line = self.line_control.read();
+            self.line_control.write(line | DLAB);
+            self.base.write(3);
+            self.interrupt_enable.write(0);
+            self.line_control.write(line);
+        }
+    }
+
+    fn init(&mut self) {
+        self.init_baud_rate();
+        unsafe {
+            self.line_control.write(NO_PARITY | EIGHT_BITS_LENGTH);
+            self.fifo_control
+                .write(FIFO | TRIGGER_LVL_14 | CLEAR_TRANSMIT_FIFO | CLEAR_REVEIVE_FIFO);
+            self.interrupt_enable.write(ENABLE_TRANSMITTER);
+        }
+    }
 }
 
 impl fmt::Write for SerialPort {
@@ -94,7 +129,7 @@ impl fmt::Write for SerialPort {
         let len: usize = self.write_string(s);
         match len {
             l if l == s.len() => Ok(()),
-            _ => Err(fmt::Error)
+            _ => Err(fmt::Error),
         }
     }
 }