Kernel: Implement PS/2 mouse driver

This is realtively simple driver that queries extensions (scroll +
extra buttons) from mouse and reads mouse packages.

kernel/CMakeLists.txt

@@ -36,6 +36,7 @@ set(KERNEL_SOURCES
 	kernel/Input/PS2/Device.cpp
 	kernel/Input/PS2/Keyboard.cpp
 	kernel/Input/PS2/Keymap.cpp
+	kernel/Input/PS2/Mouse.cpp
 	kernel/InterruptController.cpp
 	kernel/kernel.cpp
 	kernel/Memory/DMARegion.cpp

kernel/include/kernel/Input/MouseEvent.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include <stdint.h>
+
+namespace Kernel::Input
+{
+
+	enum class MouseButton
+	{
+		Left, Right, Middle, Extra1, Extra2
+	};
+
+	struct MouseButtonEvent
+	{
+		MouseButton button;
+		bool pressed;
+	};
+
+	struct MouseMoveEvent
+	{
+		int32_t rel_x;
+		int32_t rel_y;
+	};
+
+	struct MouseScrollEvent
+	{
+		int32_t scroll;
+	};
+
+	enum class MouseEventType
+	{
+		MouseButtonEvent,
+		MouseMoveEvent,
+		MouseScrollEvent,
+	};
+
+	struct MouseEvent
+	{
+		MouseEventType type;
+		union
+		{
+			MouseButtonEvent button_event;
+			MouseMoveEvent move_event;
+			MouseScrollEvent scroll_event;
+		};	
+	};
+
+}

kernel/include/kernel/Input/PS2/Mouse.h

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <kernel/Input/MouseEvent.h>
+#include <kernel/Input/PS2/Device.h>
+#include <kernel/Semaphore.h>
+
+namespace Kernel::Input
+{
+
+	class PS2Mouse final : public PS2Device
+	{
+	private:
+		enum Command : uint8_t
+		{
+			SET_SAMPLE_RATE = 0xF3
+		};
+
+	public:
+		static BAN::ErrorOr<PS2Mouse*> create(PS2Controller&);
+		virtual void send_initialize() override;
+
+		virtual void handle_byte(uint8_t) final override;
+		virtual void handle_device_command_response(uint8_t) final override;
+
+	private:
+		PS2Mouse(PS2Controller& controller);
+
+		void initialize_extensions(uint8_t);
+
+	private:
+		uint8_t m_byte_buffer[10];
+		uint8_t m_byte_index { 0 };
+
+		bool	m_enabled		{ false };
+		uint8_t m_mouse_id		{ 0x00 };
+		uint8_t m_button_mask	{ 0x00 };
+
+		BAN::CircularQueue<MouseEvent, 25> m_event_queue;
+
+		Semaphore m_semaphore;
+
+	protected:
+		virtual BAN::ErrorOr<size_t> read_impl(off_t, BAN::ByteSpan) override;
+		virtual bool has_data_impl() const override;
+	};
+
+}

kernel/kernel/Input/PS2/Controller.cpp

@@ -5,6 +5,7 @@
 #include <kernel/Input/PS2/Config.h>
 #include <kernel/Input/PS2/Controller.h>
 #include <kernel/Input/PS2/Keyboard.h>
+#include <kernel/Input/PS2/Mouse.h>
 #include <kernel/InterruptController.h>
 #include <kernel/IO.h>
 #include <kernel/Timer/Timer.h>
@@ -213,10 +214,9 @@ namespace Kernel::Input
 
 		// Standard PS/2 Mouse
 		if (index == 1 && (bytes[0] == 0x00))
-			return BAN::Error::from_error_code(ErrorCode::PS2_UnsupportedDevice);
+			m_devices[device] = TRY(PS2Mouse::create(*this));
-		
 		// MF2 Keyboard
-		if (index == 2 && (bytes[0] == 0xAB && bytes[1] == 0x83))
+		else if (index == 2 && (bytes[0] == 0xAB && bytes[1] == 0x83))
 			m_devices[device] = TRY(PS2Keyboard::create(*this));
 
 		if (m_devices[device])

kernel/kernel/Input/PS2/Mouse.cpp

@@ -0,0 +1,210 @@
+#include <BAN/ScopeGuard.h>
+#include <kernel/CriticalScope.h>
+#include <kernel/FS/DevFS/FileSystem.h>
+#include <kernel/Input/PS2/Config.h>
+#include <kernel/Input/PS2/Mouse.h>
+
+#define SET_MASK(byte, mask, on_off) ((on_off) ? ((byte) | (mask)) : ((byte) & ~(mask)))
+#define TOGGLE_MASK(byte, mask) ((byte) ^ (mask))
+
+namespace Kernel::Input
+{
+
+	BAN::ErrorOr<PS2Mouse*> PS2Mouse::create(PS2Controller& controller)
+	{
+		PS2Mouse* mouse = new PS2Mouse(controller);
+		if (mouse == nullptr)
+			return BAN::Error::from_errno(ENOMEM);
+		return mouse;
+	}
+
+	PS2Mouse::PS2Mouse(PS2Controller& controller)
+		: PS2Device(controller)
+	{ }
+
+	void PS2Mouse::send_initialize()
+	{
+		// Query extensions
+		append_command_queue(Command::SET_SAMPLE_RATE, 200);
+		append_command_queue(Command::SET_SAMPLE_RATE, 100);
+		append_command_queue(Command::SET_SAMPLE_RATE, 80);
+		append_command_queue(PS2::DeviceCommand::IDENTIFY);
+	}
+
+	void PS2Mouse::initialize_extensions(uint8_t byte)
+	{
+		ASSERT(!m_enabled);
+
+		switch (byte)
+		{
+			case 0x00:
+				m_mouse_id = 0x00;
+				m_enabled = true;
+				break;
+			case 0x03:
+				if (m_mouse_id == 0x03)
+					m_enabled = true;
+				else
+				{
+					m_mouse_id = 0x03;
+					append_command_queue(Command::SET_SAMPLE_RATE, 200);
+					append_command_queue(Command::SET_SAMPLE_RATE, 200);
+					append_command_queue(Command::SET_SAMPLE_RATE, 80);
+					append_command_queue(PS2::DeviceCommand::IDENTIFY);
+				}
+				break;
+			case 0x04:
+				m_mouse_id = 0x04;
+				m_enabled = true;
+				break;
+			default:
+				dprintln("PS/2 Mouse: unknown id {2H}", byte);
+				break;
+		}
+
+		if (m_enabled)
+		{
+			append_command_queue(Command::SET_SAMPLE_RATE, 100);
+			append_command_queue(PS2::DeviceCommand::ENABLE_SCANNING);
+		}
+	}
+
+	void PS2Mouse::handle_device_command_response(uint8_t byte)
+	{
+		switch (byte)
+		{
+			default:
+				dwarnln("Unhandeled byte {2H}", byte);
+				break;
+		}
+	}
+
+	void PS2Mouse::handle_byte(uint8_t byte)
+	{
+		if (!m_enabled)
+			return initialize_extensions(byte);
+
+		m_byte_buffer[m_byte_index++] = byte;
+		if (!(m_byte_buffer[0] & 0x08))
+		{
+			dprintln("PS/2 mouse: corrupted package");
+			m_byte_index = 0;
+		}
+
+		int packet_size = (m_mouse_id == 0x00) ? 3 : 4;
+		if (m_byte_index < packet_size)
+			return;
+
+		uint8_t new_button_mask = m_byte_buffer[0] & 0b111;
+		int32_t rel_x = m_byte_buffer[1] - (((uint16_t)m_byte_buffer[0] << 4) & 0x100);
+		int32_t rel_y = m_byte_buffer[2] - (((uint16_t)m_byte_buffer[0] << 3) & 0x100);
+		int32_t rel_z = 0;
+
+		if (m_mouse_id == 0x03)
+		{
+			rel_z = (int8_t)m_byte_buffer[3];
+		}
+		else if (m_mouse_id == 0x04)
+		{
+			new_button_mask |= (m_byte_buffer[3] >> 1) & 0b11000;
+
+			// sign extend z value
+			if (m_byte_buffer[3] & 0x08)
+				m_byte_buffer[3] |= 0xF0;
+			rel_z = (int8_t)m_byte_buffer[3];
+		}
+
+		m_byte_index = 0;
+
+		// Max 7 events, one for each (5) button, one for movement, one for scroll
+		BAN::Array<MouseEvent, 7> events;
+		int event_count = 0;
+
+		auto button_index_to_button =
+			[](int index) -> MouseButton
+			{
+				if (index == 0)
+					return MouseButton::Left;
+				if (index == 1)
+					return MouseButton::Right;
+				if (index == 2)
+					return MouseButton::Middle;
+				if (index == 3)
+					return MouseButton::Extra1;
+				if (index == 4)
+					return MouseButton::Extra2;
+				ASSERT_NOT_REACHED();
+			};
+
+		if (new_button_mask != m_button_mask)
+		{
+			for (int i = 0; i < 5; i++)
+			{
+				if ((new_button_mask & (1 << i)) == (m_button_mask & (1 << i)))
+					continue;
+				
+				auto& event = events[event_count++];
+				event.type = MouseEventType::MouseButtonEvent;
+				event.button_event.button = button_index_to_button(i);
+				event.button_event.pressed = !!(new_button_mask & (1 << i));
+			}
+
+			m_button_mask = new_button_mask;
+		}
+
+		if (rel_x || rel_y)
+		{
+			auto& event = events[event_count++];
+			event.type = MouseEventType::MouseMoveEvent;
+			event.move_event.rel_x = rel_x;
+			event.move_event.rel_y = rel_y;
+		}
+
+		if (rel_z)
+		{
+			auto& event = events[event_count++];
+			event.type = MouseEventType::MouseScrollEvent;
+			event.scroll_event.scroll = rel_z;
+		}
+
+		for (int i = 0; i < event_count; i++)
+		{
+			if (m_event_queue.full())
+			{
+				dwarnln("PS/2 event queue full");
+				m_event_queue.pop();
+			}
+			m_event_queue.push(events[i]);
+		}
+
+		m_semaphore.unblock();
+	}
+
+	BAN::ErrorOr<size_t> PS2Mouse::read_impl(off_t, BAN::ByteSpan buffer)
+	{
+		if (buffer.size() < sizeof(MouseEvent))
+			return BAN::Error::from_errno(ENOBUFS);
+
+		while (true)
+		{
+			if (m_event_queue.empty())
+				m_semaphore.block();
+
+			CriticalScope _;
+			if (m_event_queue.empty())
+				continue;
+
+			buffer.as<MouseEvent>() = m_event_queue.front();
+			m_event_queue.pop();
+
+			return sizeof(MouseEvent);
+		}
+	}
+
+	bool PS2Mouse::has_data_impl() const
+	{
+		CriticalScope _;
+		return !m_event_queue.empty();
+	}
+
+}