Kernel: Introduce a new HID subsystem

The end goal of this commit is to allow to boot on bare metal with no
PS/2 device connected to the system. It turned out that the original
code relied on the existence of the PS/2 keyboard, so VirtualConsole
called it even though ACPI indicated the there's no i8042 controller on
my real machine because I didn't plug any PS/2 device.
The code is much more flexible, so adding HID support for other type of
hardware (e.g. USB HID) could be much simpler.

Briefly describing the change, we have a new singleton called
HIDManagement, which is responsible to initialize the i8042 controller
if exists, and to enumerate its devices. I also abstracted a bit
things, so now every Human interface device is represented with the
HIDDevice class. Then, there are 2 types of it - the MouseDevice and
KeyboardDevice classes; both are responsible to handle the interface in
the DevFS.

PS2KeyboardDevice, PS2MouseDevice and VMWareMouseDevice classes are
responsible for handling the hardware-specific interface they are
assigned to. Therefore, they are inheriting from the IRQHandler class.

1 files changed, 84 insertions, 0 deletions

diff --git a/Kernel/Devices/HID/KeyboardDevice.h b/Kernel/Devices/HID/KeyboardDevice.h
new file mode 100644
index 0000000000..3d06571ba5
--- /dev/null
+++ b/Kernel/Devices/HID/KeyboardDevice.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2021, Liav A. <liavalb@hotmail.co.il>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include <AK/CircularQueue.h>
+#include <AK/DoublyLinkedList.h>
+#include <AK/Types.h>
+#include <Kernel/API/KeyCode.h>
+#include <Kernel/Devices/CharacterDevice.h>
+#include <Kernel/Devices/HID/HIDDevice.h>
+#include <Kernel/Interrupts/IRQHandler.h>
+#include <Kernel/Random.h>
+
+namespace Kernel {
+
+class KeyboardDevice : public HIDDevice {
+public:
+    using Event = KeyEvent;
+
+    virtual ~KeyboardDevice() override;
+
+    // ^CharacterDevice
+    virtual KResultOr<size_t> read(FileDescription&, u64, UserOrKernelBuffer&, size_t) override;
+    virtual bool can_read(const FileDescription&, size_t) const override;
+    virtual KResultOr<size_t> write(FileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
+    virtual bool can_write(const FileDescription&, size_t) const override { return true; }
+
+    // ^HIDDevice
+    virtual Type instrument_type() const { return Type::Keyboard; }
+
+    // ^Device
+    virtual mode_t required_mode() const override { return 0440; }
+
+    //FIXME: It should be something like String::formatted("keyboard{}", minor())
+    // instead of a fixed string like this
+    virtual String device_name() const override { return "keyboard"; }
+
+    void update_modifier(u8 modifier, bool state)
+    {
+        if (state)
+            m_modifiers |= modifier;
+        else
+            m_modifiers &= ~modifier;
+    }
+
+protected:
+    KeyboardDevice();
+    mutable SpinLock<u8> m_queue_lock;
+    CircularQueue<Event, 16> m_queue;
+    // ^CharacterDevice
+    virtual const char* class_name() const override { return "KeyboardDevice"; }
+
+    u8 m_modifiers { 0 };
+    bool m_caps_lock_on { false };
+    bool m_num_lock_on { false };
+    bool m_has_e0_prefix { false };
+
+    void key_state_changed(u8 raw, bool pressed);
+};
+}