asterinas/kernel/comps/keyboard/src/i8042_chip/keyboard.rs

358 lines
11 KiB
Rust

// SPDX-License-Identifier: MPL-2.0
//! The i8042 keyboard driver.
use alloc::{string::String, sync::Arc};
use core::sync::atomic::{AtomicBool, Ordering};
use aster_input::{
event_type_codes::{KeyCode, KeyStatus, SynEvent},
input_dev::{InputCapability, InputDevice, InputEvent, InputId, RegisteredInputDevice},
};
use ostd::{
arch::{
irq::{MappedIrqLine, IRQ_CHIP},
trap::TrapFrame,
},
irq::IrqLine,
};
use spin::Once;
use super::controller::{
I8042Controller, I8042ControllerError, I8042_CONTROLLER, PS2_ACK, PS2_BAT_OK, PS2_CMD_RESET,
};
use crate::alloc::string::ToString;
/// IRQ line for i8042 keyboard.
static IRQ_LINE: Once<MappedIrqLine> = Once::new();
/// Registered device instance for event submission.
static REGISTERED_DEVICE: Once<RegisteredInputDevice> = Once::new();
/// ISA interrupt number for i8042 keyboard.
const ISA_INTR_NUM: u8 = 1;
pub(super) fn init(controller: &mut I8042Controller) -> Result<(), I8042ControllerError> {
// Reset keyboard device by sending `PS2_CMD_RESET` (reset command, supported by all PS/2 devices) to port 1
// and waiting for a response.
controller.wait_and_send_data(PS2_CMD_RESET)?;
// The response should be `PS2_ACK` and `PS2_BAT_OK`, followed by the device PS/2 ID.
if controller.wait_and_recv_data()? != PS2_ACK {
return Err(I8042ControllerError::DeviceResetFailed);
}
// The reset command may take some time to finish. Try again a few times.
if (0..5).find_map(|_| controller.wait_and_recv_data().ok()) != Some(PS2_BAT_OK) {
return Err(I8042ControllerError::DeviceResetFailed);
}
// See <https://wiki.osdev.org/I8042_PS/2_Controller#Detecting_PS/2_Device_Types> for a list of IDs.
let mut iter = core::iter::from_fn(|| controller.wait_and_recv_data().ok());
match (iter.next(), iter.next()) {
// Ancient AT keyboard
(None, None) => (),
// Other devices, including other kinds of keyboards (TODO: Support other kinds of keyboards)
_ => return Err(I8042ControllerError::DeviceUnknown),
}
let mut irq_line = IrqLine::alloc()
.and_then(|irq_line| {
IRQ_CHIP
.get()
.unwrap()
.map_isa_pin_to(irq_line, ISA_INTR_NUM)
})
.map_err(|_| I8042ControllerError::DeviceAllocIrqFailed)?;
irq_line.on_active(handle_keyboard_input);
IRQ_LINE.call_once(|| irq_line);
// Create and register the i8042 keyboard device.
let keyboard_device = Arc::new(I8042Keyboard::new());
let registered_device = aster_input::register_device(keyboard_device);
REGISTERED_DEVICE.call_once(|| registered_device);
Ok(())
}
#[derive(Debug)]
struct I8042Keyboard {
name: String,
phys: String,
uniq: String,
id: InputId,
capability: InputCapability,
}
impl I8042Keyboard {
fn new() -> Self {
let mut capability = InputCapability::new();
capability.set_supported_event_type(aster_input::event_type_codes::EventTypes::KEY);
capability.set_supported_event_type(aster_input::event_type_codes::EventTypes::SYN);
// Add all standard keyboard keys.
capability.add_standard_keyboard_keys();
Self {
// Standard name for i8042 PS/2 keyboard devices.
name: "i8042_keyboard".to_string(),
// Physical path describing the device's connection topology
// isa0060: ISA bus port 0x60 (i8042 data port)
// serio0: Serial I/O device 0 (PS/2 is a serial protocol)
// input0: Input device 0 (first input device on this controller)
phys: "isa0060/serio0/input0".to_string(),
// Unique identifier - empty string because traditional i8042 keyboards
// don't have unique hardware identifiers like serial numbers or MAC addresses
uniq: "".to_string(),
// Device ID with standard values for i8042 keyboards
// BUS_I8042 (0x11): PS/2 interface bus type
// vendor (0x0001): Generic vendor ID for standard keyboards
// product (0x0001): Generic product ID for standard keyboards
// version (0x0001): Version 1.0 - standard PS/2 keyboard protocol
id: InputId::new(InputId::BUS_I8042, 0x0001, 0x0001, 0x0001),
capability,
}
}
}
impl InputDevice for I8042Keyboard {
fn name(&self) -> &str {
&self.name
}
fn phys(&self) -> &str {
&self.phys
}
fn uniq(&self) -> &str {
&self.uniq
}
fn id(&self) -> InputId {
self.id
}
fn capability(&self) -> &InputCapability {
&self.capability
}
}
fn handle_keyboard_input(_trap_frame: &TrapFrame) {
if !I8042_CONTROLLER.is_completed() {
return;
}
let Some(scancode_event) = ScancodeInfo::read() else {
return;
};
// Dispatch the input event.
if let Some(key_code) = scancode_event.to_key_code() {
if let Some(registered_device) = REGISTERED_DEVICE.get() {
let events = [
InputEvent::from_key_and_status(key_code, scancode_event.key_status),
InputEvent::from_sync_event(SynEvent::Report),
];
registered_device.submit_events(&events);
}
} else {
log::debug!(
"i8042 keyboard unmapped scancode {:?} dropped",
scancode_event.scancode
);
}
}
/// A scan code in the Scan Code Set 1.
///
/// Reference: <https://wiki.osdev.org/PS/2_Keyboard#Scan_Code_Set_1>.
#[derive(Debug, Clone, Copy)]
struct ScanCode(u8);
impl ScanCode {
const CODE_ERROR: u8 = 0xFF;
const CODE_EXT_PREFIX: u8 = 0xE0;
const RELEASE_MASK: u8 = 0x80;
fn has_error(&self) -> bool {
// Key detection error or internal buffer overrun.
self.0 == Self::CODE_ERROR
}
fn key_status(&self) -> KeyStatus {
if self.0 & Self::RELEASE_MASK == 0 {
KeyStatus::Pressed
} else {
KeyStatus::Released
}
}
fn is_extension(&self) -> bool {
self.0 == Self::CODE_EXT_PREFIX
}
fn key(&self) -> u8 {
self.0 & !Self::RELEASE_MASK
}
}
/// Scancode value and relevant modifier states.
#[derive(Debug, Clone)]
struct ScancodeInfo {
scancode: ScanCode,
key_status: KeyStatus,
extended: bool,
}
impl ScancodeInfo {
/// Reads the keyboard [`ScanCode`] from the i8042 controller.
fn read() -> Option<Self> {
static EXTENDED_KEY: AtomicBool = AtomicBool::new(false);
let Some(data) = I8042_CONTROLLER.get().unwrap().lock().receive_data() else {
log::warn!("i8042 keyboard has no input data");
return None;
};
let code = ScanCode(data);
if code.has_error() {
log::warn!("i8042 keyboard key detection error or internal buffer overrun");
return None;
}
// Handle the extension code.
if code.is_extension() {
EXTENDED_KEY.store(true, Ordering::Relaxed);
return None;
}
let key_status = code.key_status();
let extended = EXTENDED_KEY.load(Ordering::Relaxed);
// Clear extended flag if this is not an extended key.
if extended {
EXTENDED_KEY.store(false, Ordering::Relaxed);
}
Some(Self {
scancode: code,
key_status,
extended,
})
}
/// Maps the keyboard [`ScanCode`] to a [`KeyCode`] in the input subsystem.
fn to_key_code(&self) -> Option<KeyCode> {
// Remove the release bit.
let code = self.scancode.key();
// Handle extended keys.
if self.extended {
return match code {
0x47 => Some(KeyCode::Home),
0x48 => Some(KeyCode::Up),
0x49 => Some(KeyCode::PageUp),
0x4B => Some(KeyCode::Left),
0x4D => Some(KeyCode::Right),
0x4F => Some(KeyCode::End),
0x50 => Some(KeyCode::Down),
0x51 => Some(KeyCode::PageDown),
0x52 => Some(KeyCode::Insert),
0x53 => Some(KeyCode::Delete),
_ => None,
};
}
// Standard key mapping.
Some(match code {
// Letters - handle shift/caps lock
0x1E => KeyCode::A,
0x30 => KeyCode::B,
0x2E => KeyCode::C,
0x20 => KeyCode::D,
0x12 => KeyCode::E,
0x21 => KeyCode::F,
0x22 => KeyCode::G,
0x23 => KeyCode::H,
0x17 => KeyCode::I,
0x24 => KeyCode::J,
0x25 => KeyCode::K,
0x26 => KeyCode::L,
0x32 => KeyCode::M,
0x31 => KeyCode::N,
0x18 => KeyCode::O,
0x19 => KeyCode::P,
0x10 => KeyCode::Q,
0x13 => KeyCode::R,
0x1F => KeyCode::S,
0x14 => KeyCode::T,
0x16 => KeyCode::U,
0x2F => KeyCode::V,
0x11 => KeyCode::W,
0x2D => KeyCode::X,
0x15 => KeyCode::Y,
0x2C => KeyCode::Z,
// Digits
0x02 => KeyCode::Num1,
0x03 => KeyCode::Num2,
0x04 => KeyCode::Num3,
0x05 => KeyCode::Num4,
0x06 => KeyCode::Num5,
0x07 => KeyCode::Num6,
0x08 => KeyCode::Num7,
0x09 => KeyCode::Num8,
0x0A => KeyCode::Num9,
0x0B => KeyCode::Num0,
// Whitespace and control
0x39 => KeyCode::Space,
0x0F => KeyCode::Tab,
0x1C => KeyCode::Enter,
0x0E => KeyCode::Backspace,
// Punctuation
0x0C => KeyCode::Minus,
0x0D => KeyCode::Equal,
0x29 => KeyCode::Grave,
0x2B => KeyCode::Backslash,
0x33 => KeyCode::Comma,
0x34 => KeyCode::Dot,
0x35 => KeyCode::Slash,
0x27 => KeyCode::Semicolon,
0x28 => KeyCode::Apostrophe,
0x1A => KeyCode::LeftBrace,
0x1B => KeyCode::RightBrace,
// Modifier keys
0x1D => KeyCode::LeftCtrl,
0x2A => KeyCode::LeftShift,
0x38 => KeyCode::LeftAlt,
0x3A => KeyCode::CapsLock,
// Function keys
0x3B => KeyCode::F1,
0x3C => KeyCode::F2,
0x3D => KeyCode::F3,
0x3E => KeyCode::F4,
0x3F => KeyCode::F5,
0x40 => KeyCode::F6,
0x41 => KeyCode::F7,
0x42 => KeyCode::F8,
0x43 => KeyCode::F9,
0x44 => KeyCode::F10,
0x57 => KeyCode::F11,
0x58 => KeyCode::F12,
// Escape
0x01 => KeyCode::Esc,
// Unhandled mappings -> None
_ => return None,
})
}
}