Kernel: Add I8042Controller to detect and manage PS/2 devices

Rework the PS/2 keyboard and mouse drivers to use a common 8042
controller driver. Also, reset and reconfigure the 8042 controller
as they are not guaranteed to be in the state that we expect.

Kernel/Devices/I8042Controller.h

@@ -0,0 +1,130 @@
+/*
+ * Copyright (c) 2020, The SerenityOS developers.
+ * 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 <Kernel/SpinLock.h>
+
+namespace Kernel {
+
+#define I8042_BUFFER 0x60
+#define I8042_STATUS 0x64
+#define I8042_ACK 0xFA
+#define I8042_RESEND 0xFE
+#define I8042_BUFFER_FULL 0x01
+
+#define I8042_WHICH_BUFFER 0x20
+
+#define I8042_KEYBOARD_BUFFER 0x00
+#define I8042_MOUSE_BUFFER 0x20
+
+class I8042Device {
+public:
+    virtual ~I8042Device() { }
+
+    virtual void irq_handle_byte_read(u8 byte) = 0;
+    virtual void enable_interrupts() = 0;
+};
+
+class I8042Controller {
+public:
+    enum class Device {
+        None = 0,
+        Keyboard,
+        Mouse
+    };
+
+    static void initialize();
+    static I8042Controller& the();
+
+    bool reset_device(Device device)
+    {
+        ScopedSpinLock lock(m_lock);
+        return do_reset_device(device);
+    }
+
+    u8 send_command(Device device, u8 command)
+    {
+        ScopedSpinLock lock(m_lock);
+        return do_send_command(device, command);
+    }
+    u8 send_command(Device device, u8 command, u8 data)
+    {
+        ScopedSpinLock lock(m_lock);
+        return do_send_command(device, command, data);
+    }
+
+    u8 read_from_device(Device device)
+    {
+        ScopedSpinLock lock(m_lock);
+        return do_read_from_device(device);
+    }
+
+    void wait_then_write(u8 port, u8 data)
+    {
+        ScopedSpinLock lock(m_lock);
+        do_wait_then_write(port, data);
+    }
+
+    u8 wait_then_read(u8 port)
+    {
+        ScopedSpinLock lock(m_lock);
+        return do_wait_then_read(port);
+    }
+
+    void prepare_for_output();
+    void prepare_for_input(Device);
+
+    void irq_process_input_buffer(Device);
+
+private:
+    I8042Controller();
+    void do_drain();
+    bool do_reset_device(Device device);
+    u8 do_send_command(Device device, u8 data);
+    u8 do_send_command(Device device, u8 command, u8 data);
+    u8 do_write_to_device(Device device, u8 data);
+    u8 do_read_from_device(Device device);
+    void do_wait_then_write(u8 port, u8 data);
+    u8 do_wait_then_read(u8 port);
+
+    static int device_to_deviceinfo_index(Device device)
+    {
+        ASSERT(device != Device::None);
+        return (device == Device::Keyboard) ? 0 : 1;
+    }
+
+    struct DeviceInfo {
+        I8042Device* device { nullptr };
+        bool available { false };
+    };
+
+    SpinLock<u8> m_lock;
+    bool m_is_dual_channel { false };
+    DeviceInfo m_devices[2];
+};
+
+}