1 files changed, 103 insertions, 0 deletions
diff --git a/Kernel/Devices/Audio/IntelHDA/Stream.h b/Kernel/Devices/Audio/IntelHDA/Stream.h
new file mode 100644
index 0000000000..eb61165a19
--- /dev/null
+++ b/Kernel/Devices/Audio/IntelHDA/Stream.h
@@ -0,0 +1,103 @@
+/*
+ * Copyright (c) 2023, Jelle Raaijmakers <jelle@gmta.nl>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Error.h>
+#include <AK/NonnullOwnPtr.h>
+#include <AK/OwnPtr.h>
+#include <Kernel/Devices/Audio/IntelHDA/Codec.h>
+#include <Kernel/Devices/Audio/IntelHDA/Format.h>
+#include <Kernel/IOWindow.h>
+#include <Kernel/Locking/SpinlockProtected.h>
+
+namespace Kernel::Audio::IntelHDA {
+
+class Stream {
+public:
+    static constexpr u32 cyclic_buffer_size_in_ms = 40;
+
+    u8 stream_number() const { return m_stream_number; }
+    bool running() const { return m_running; }
+    u32 sample_rate() const { return m_format_parameters.sample_rate; }
+
+    void start();
+    ErrorOr<void> stop();
+
+    ErrorOr<void> set_format(FormatParameters);
+
+protected:
+    // We always need 2 filled buffers, plus an additional one to prevent buffer underrun
+    static constexpr u8 minimum_number_of_buffers = 3;
+
+    // 3.3: High Definition Audio Controller Register Set - streams
+    enum StreamRegisterOffset : u8 {
+        Control = 0x00,
+        Status = 0x03,
+        LinkPosition = 0x04,
+        CyclicBufferLength = 0x08,
+        LastValidIndex = 0x0c,
+        Format = 0x12,
+        BDLLowerBaseAddress = 0x18,
+        BDLUpperBaseAddress = 0x1c,
+    };
+
+    // 3.3.35: Input/Output/Bidirectional Stream Descriptor Control
+    enum StreamControlFlag : u32 {
+        StreamReset = 1u << 0,
+        StreamRun = 1u << 1,
+    };
+
+    Stream(NonnullOwnPtr<IOWindow> stream_io_window, u8 stream_number)
+        : m_stream_io_window(move(stream_io_window))
+        , m_stream_number(stream_number)
+    {
+    }
+
+    ~Stream();
+
+    u32 read_control();
+    void write_control(u32);
+
+    ErrorOr<void> initialize_buffer();
+    ErrorOr<void> reset();
+
+    NonnullOwnPtr<IOWindow> m_stream_io_window;
+    u8 m_stream_number;
+    OwnPtr<Memory::Region> m_buffer_descriptor_list;
+    SpinlockProtected<OwnPtr<Memory::Region>, LockRank::None> m_buffers;
+    size_t m_buffer_position { 0 };
+    bool m_running { false };
+    FormatParameters m_format_parameters;
+};
+
+class OutputStream : public Stream {
+public:
+    static constexpr u8 fixed_channel = 0;
+
+    static ErrorOr<NonnullOwnPtr<OutputStream>> create(NonnullOwnPtr<IOWindow> stream_io_window, u8 stream_number)
+    {
+        return adopt_nonnull_own_or_enomem(new (nothrow) OutputStream(move(stream_io_window), stream_number));
+    }
+
+    ErrorOr<size_t> write(UserOrKernelBuffer const&, size_t);
+
+private:
+    OutputStream(NonnullOwnPtr<IOWindow> stream_io_window, u8 stream_number)
+        : Stream(move(stream_io_window), stream_number)
+    {
+        // 3.3.35: Input/Output/Bidirectional Stream Descriptor Control
+        //         "Although the controller hardware is capable of transmitting any stream number,
+        //          by convention stream 0 is reserved as unused by software, so that converters
+        //          whose stream numbers have been reset to 0 do not unintentionally decode data
+        //          not intended for them."
+        VERIFY(stream_number >= 1);
+    }
+};
+
+// FIXME: implement InputStream and BidirectionalStream
+
+}