refactor: move ps/2 io operations to separate file

src/ps2/controller.rs

@@ -1,15 +1,11 @@
 /// https://wiki.osdev.org/%228042%22_PS/2_Controller
-use core::arch::asm;
-
-use super::{Key, scancodes::SCANCODE_TO_KEY};
-
-const DATA_PORT: u16 = 0x60;
-const STATUS_PORT: u16 = 0x64;
-const COMMAND_PORT: u16 = 0x64;
-const OUTPUT_BUFFER_STATUS_BIT: u8 = 1;
+use crate::ps2::{
+    DATA_PORT,
+    io::{flush_output_buffer, read, send_command, send_data, wait_for_data},
+};
 
 #[repr(u8)]
-enum Command {
+pub enum Command {
     DisableFirstPort = 0xAD,
     DisableSecondPort = 0xA7,
     EnableFirstPort = 0xAE,
@@ -22,7 +18,7 @@ enum Command {
 }
 
 #[repr(u8)]
-enum Status {
+pub enum Status {
     OutputFull = 0x01,
     InputFull = 0x02,
 }
@@ -293,110 +289,3 @@ pub fn init() -> Result<(), &'static str> {
 
     Ok(())
 }
-
-fn send_command(cmd: Command) {
-    while unsafe { read(STATUS_PORT) } & Status::InputFull as u8 != 0 {}
-
-    unsafe { write(COMMAND_PORT, cmd as u8) };
-}
-
-fn send_data(data: u8) {
-    while unsafe { read(STATUS_PORT) } & Status::InputFull as u8 != 0 {}
-
-    unsafe { write(DATA_PORT, data) };
-}
-
-fn wait_for_data() -> u8 {
-    while unsafe { read(STATUS_PORT) } & Status::OutputFull as u8 == 0 {}
-
-    unsafe { read(DATA_PORT) }
-}
-
-/// Reads all data from the output buffer, flushing it. Note that this will
-/// go into an endless loop if called without disabling the ports first.
-fn flush_output_buffer() {
-    while unsafe { read(STATUS_PORT) } & Status::OutputFull as u8 != 0 {
-        unsafe { read(DATA_PORT) };
-    }
-}
-
-static mut LAST_KEY: Option<u8> = None;
-
-/// Reads from the PS2 data port if the PS2 status port is ready. Returns `Some(KeyScanCode)`
-/// if the converted scancode is a supported character.
-///
-/// /// ### Example Usage:
-/// ```
-/// let mut v = Vga::new();
-///
-/// if let Some(c) = read_if_ready() == KeyScanCode::A {
-///     v.write_char(b'a');
-/// }
-pub fn read_if_ready() -> Option<Key> {
-    if !is_ps2_data_available() {
-        return None;
-    }
-
-    let code = unsafe { read(DATA_PORT) };
-
-    if code == 0xF0 {
-        while !is_ps2_data_available() {}
-        let _ = unsafe { read(DATA_PORT) };
-        unsafe { LAST_KEY = None };
-        return None;
-    }
-
-    if code == 0xE0 {
-        while !is_ps2_data_available() {}
-        let extended_code = unsafe { read(DATA_PORT) };
-        unsafe { LAST_KEY = Some(extended_code) };
-        return SCANCODE_TO_KEY[extended_code as usize].1;
-    }
-
-    unsafe { LAST_KEY = Some(code) };
-    SCANCODE_TO_KEY[code as usize].1
-}
-
-/// Returns `true` if the PS2 input buffer has data ready to be read,
-/// meaning the least significant bit of the PS2 status port is set.
-fn is_ps2_data_available() -> bool {
-    status() & OUTPUT_BUFFER_STATUS_BIT != 0
-}
-
-/// Reads from `STATUS_PORT` and returns the extracted value.
-fn status() -> u8 {
-    let res: u8;
-
-    unsafe {
-        res = read(STATUS_PORT);
-    }
-
-    res
-}
-
-/// Reads from `port` and returns the extracted value.
-unsafe fn read(port: u16) -> u8 {
-    assert!(port == DATA_PORT || port == STATUS_PORT);
-
-    let res: u8;
-
-    unsafe {
-        asm!(
-            "in al, dx",
-            in("dx") port,
-            out("al") res,
-        );
-    }
-
-    res
-}
-
-unsafe fn write(port: u16, val: u8) {
-    unsafe {
-        asm!(
-            "out dx, al",
-            in("dx") port,
-            in("al") val,
-        );
-    }
-}

src/ps2/io.rs

@@ -0,0 +1,114 @@
+use core::arch::asm;
+
+use super::{
+    COMMAND_PORT, DATA_PORT, Key, OUTPUT_BUFFER_STATUS_BIT, STATUS_PORT,
+    controller::{Command, Status},
+    scancodes::SCANCODE_TO_KEY,
+};
+
+pub fn send_command(cmd: Command) {
+    while unsafe { read(STATUS_PORT) } & Status::InputFull as u8 != 0 {}
+
+    unsafe { write(COMMAND_PORT, cmd as u8) };
+}
+
+pub fn send_data(data: u8) {
+    while unsafe { read(STATUS_PORT) } & Status::InputFull as u8 != 0 {}
+
+    unsafe { write(DATA_PORT, data) };
+}
+
+pub fn wait_for_data() -> u8 {
+    while unsafe { read(STATUS_PORT) } & Status::OutputFull as u8 == 0 {}
+
+    unsafe { read(DATA_PORT) }
+}
+
+/// Reads all data from the output buffer, flushing it. Note that this will
+/// go into an endless loop if called without disabling the ports first.
+pub fn flush_output_buffer() {
+    while unsafe { read(STATUS_PORT) } & Status::OutputFull as u8 != 0 {
+        unsafe { read(DATA_PORT) };
+    }
+}
+
+static mut LAST_KEY: Option<u8> = None;
+
+/// Reads from the PS2 data port if the PS2 status port is ready. Returns `Some(KeyScanCode)`
+/// if the converted scancode is a supported character.
+///
+/// /// ### Example Usage:
+/// ```
+/// let mut v = Vga::new();
+///
+/// if let Some(c) = read_if_ready() == KeyScanCode::A {
+///     v.write_char(b'a');
+/// }
+pub fn read_if_ready() -> Option<Key> {
+    if !is_ps2_data_available() {
+        return None;
+    }
+
+    let code = unsafe { read(DATA_PORT) };
+
+    if code == 0xF0 {
+        while !is_ps2_data_available() {}
+        let _ = unsafe { read(DATA_PORT) };
+        unsafe { LAST_KEY = None };
+        return None;
+    }
+
+    if code == 0xE0 {
+        while !is_ps2_data_available() {}
+        let extended_code = unsafe { read(DATA_PORT) };
+        unsafe { LAST_KEY = Some(extended_code) };
+        return SCANCODE_TO_KEY[extended_code as usize].1;
+    }
+
+    unsafe { LAST_KEY = Some(code) };
+    SCANCODE_TO_KEY[code as usize].1
+}
+
+/// Returns `true` if the PS2 input buffer has data ready to be read,
+/// meaning the least significant bit of the PS2 status port is set.
+fn is_ps2_data_available() -> bool {
+    status() & OUTPUT_BUFFER_STATUS_BIT != 0
+}
+
+/// Reads from `STATUS_PORT` and returns the extracted value.
+fn status() -> u8 {
+    let res: u8;
+
+    unsafe {
+        res = read(STATUS_PORT);
+    }
+
+    res
+}
+
+/// Reads from `port` and returns the extracted value.
+pub unsafe fn read(port: u16) -> u8 {
+    assert!(port == DATA_PORT || port == STATUS_PORT);
+
+    let res: u8;
+
+    unsafe {
+        asm!(
+            "in al, dx",
+            in("dx") port,
+            out("al") res,
+        );
+    }
+
+    res
+}
+
+unsafe fn write(port: u16, val: u8) {
+    unsafe {
+        asm!(
+            "out dx, al",
+            in("dx") port,
+            in("al") val,
+        );
+    }
+}

src/ps2/mod.rs

@@ -1,5 +1,12 @@
 mod controller;
+mod io;
 mod scancodes;
 
-pub use controller::{init, read_if_ready};
+pub const DATA_PORT: u16 = 0x60;
+pub const STATUS_PORT: u16 = 0x64;
+pub const COMMAND_PORT: u16 = 0x64;
+pub const OUTPUT_BUFFER_STATUS_BIT: u8 = 1;
+
+pub use controller::init;
+pub use io::read_if_ready;
 pub use scancodes::Key;