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use bcm2837::mini_uart::{MiniUart, MiniUartInterruptId};
use lazy_static::lazy_static;
use core::fmt;
use spin::Mutex;
use once::*;
/// Struct to get a global SerialPort interface
pub struct SerialPort {
mu: MiniUart,
}
pub trait SerialRead {
fn receive(&mut self) -> u8;
}
impl SerialPort {
/// Creates a new instance of `SerialPort`.
fn new() -> SerialPort {
SerialPort {
mu: MiniUart::new(),
}
}
/// Init a newly created SerialPort, can only be called once.
fn init(&mut self) {
assert_has_not_been_called!("SerialPort::init must be called only once");
self.mu.init();
super::irq::register_irq(super::irq::Interrupt::Aux, handle_serial_irq);
}
/// Writes the byte `byte` to the UART device.
fn write_byte(&mut self, byte: u8) {
self.mu.write_byte(byte)
}
/// Reads a byte from the UART device, blocking until a byte is available.
fn read_byte(&self) -> u8 {
self.mu.read_byte()
}
// Whether the interrupt `id` is pending.
fn interrupt_is_pending(&self, id: MiniUartInterruptId) -> bool {
self.mu.interrupt_is_pending(id)
}
}
impl SerialRead for SerialPort {
fn receive(&mut self) -> u8 {
self.read_byte()
}
}
impl fmt::Write for SerialPort {
fn write_str(&mut self, s: &str) -> fmt::Result {
for byte in s.bytes() {
match byte {
// Backspace
b'\x7f' => {
self.write_byte(b'\x08');
self.write_byte(b' ');
self.write_byte(b'\x08');
}
// Return
b'\n' => {
self.write_byte(b'\r');
self.write_byte(b'\n');
}
// Others
_ => self.write_byte(byte),
}
}
Ok(())
}
}
fn handle_serial_irq() {
let serial = SERIAL_PORT.lock();
if serial.interrupt_is_pending(MiniUartInterruptId::Recive) {
crate::trap::serial(serial.read_byte() as char)
}
}
lazy_static! {
pub static ref SERIAL_PORT: Mutex<SerialPort> = Mutex::new(SerialPort::new());
}
pub fn init() {
SERIAL_PORT.lock().init();
}