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#![no_std]
#![warn(missing_docs)]
use bitflags::bitflags;
use core::fmt;
use x86_64::instructions::port::Port;
macro_rules! wait_for {
($cond:expr) => {
while !$cond {
core::sync::atomic::spin_loop_hint()
}
};
}
bitflags! {
struct IntEnFlags: u8 {
const RECEIVED = 1;
const SENT = 1 << 1;
const ERRORED = 1 << 2;
const STATUS_CHANGE = 1 << 3;
}
}
bitflags! {
struct LineStsFlags: u8 {
const INPUT_FULL = 1;
const OUTPUT_EMPTY = 1 << 5;
}
}
pub struct SerialPort {
data: Port<u8>,
int_en: Port<u8>,
fifo_ctrl: Port<u8>,
line_ctrl: Port<u8>,
modem_ctrl: Port<u8>,
line_sts: Port<u8>,
}
impl SerialPort {
#[cfg(feature = "nightly")]
pub const unsafe fn new(base: u16) -> SerialPort {
SerialPort {
data: Port::new(base),
int_en: Port::new(base + 1),
fifo_ctrl: Port::new(base + 2),
line_ctrl: Port::new(base + 3),
modem_ctrl: Port::new(base + 4),
line_sts: Port::new(base + 5),
}
}
#[cfg(not(feature = "nightly"))]
pub unsafe fn new(base: u16) -> SerialPort {
SerialPort {
data: Port::new(base),
int_en: Port::new(base + 1),
fifo_ctrl: Port::new(base + 2),
line_ctrl: Port::new(base + 3),
modem_ctrl: Port::new(base + 4),
line_sts: Port::new(base + 5),
}
}
pub fn init(&mut self) {
unsafe {
self.int_en.write(0x00);
self.line_ctrl.write(0x80);
self.data.write(0x03);
self.int_en.write(0x00);
self.line_ctrl.write(0x03);
self.fifo_ctrl.write(0xC7);
self.modem_ctrl.write(0x0B);
self.int_en.write(0x01);
}
}
fn line_sts(&mut self) -> LineStsFlags {
unsafe { LineStsFlags::from_bits_truncate(self.line_sts.read()) }
}
pub fn send(&mut self, data: u8) {
unsafe {
match data {
8 | 0x7F => {
wait_for!(self.line_sts().contains(LineStsFlags::OUTPUT_EMPTY));
self.data.write(8);
wait_for!(self.line_sts().contains(LineStsFlags::OUTPUT_EMPTY));
self.data.write(b' ');
wait_for!(self.line_sts().contains(LineStsFlags::OUTPUT_EMPTY));
self.data.write(8)
}
_ => {
wait_for!(self.line_sts().contains(LineStsFlags::OUTPUT_EMPTY));
self.data.write(data);
}
}
}
}
pub fn receive(&mut self) -> u8 {
unsafe {
wait_for!(self.line_sts().contains(LineStsFlags::INPUT_FULL));
self.data.read()
}
}
}
impl fmt::Write for SerialPort {
fn write_str(&mut self, s: &str) -> fmt::Result {
for byte in s.bytes() {
self.send(byte);
}
Ok(())
}
}