Kernel: Improve the aarch64 kernel source files disk layout

Kernel/Arch/aarch64/RPi/Timer.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2021, Nico Weber <thakis@chromium.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+
+namespace Prekernel {
+
+struct TimerRegisters;
+
+class Timer {
+public:
+    static Timer& the();
+
+    u64 microseconds_since_boot();
+
+    enum class ClockID {
+        Reserved = 0,
+        EMMC = 1,
+        UART = 2,
+        ARM = 3,
+        CORE = 4,
+        V3D = 5,
+        H264 = 6,
+        ISP = 7,
+        SDRAM = 8,
+        PIXEL = 9,
+        PWM = 10,
+        HEVC = 11,
+        EMMC2 = 12,
+        M2MC = 13,
+        PIXEL_BVB = 14,
+    };
+    u32 set_clock_rate(ClockID, u32 rate_hz, bool skip_setting_turbo = true);
+
+private:
+    Timer();
+
+    TimerRegisters volatile* m_registers;
+};
+
+}