Kernel: Implement AC97 audio device driver

2025-07-28 12:27:36 +00:00 · 2021-11-23 01:13:02 +01:00 · 2021-11-23 01:13:02 +01:00 · 7a2a0c1052
commit 7a2a0c1052
parent 1aafb6cd23
5 changed files with 403 additions and 0 deletions
--- a/Kernel/Devices/Audio/AC97.h
+++ b/Kernel/Devices/Audio/AC97.h
@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2021, Jelle Raaijmakers <jelle@gmta.nl>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/Arch/x86/IO.h>
+#include <Kernel/Bus/PCI/API.h>
+#include <Kernel/Bus/PCI/Device.h>
+#include <Kernel/Devices/CharacterDevice.h>
+#include <Kernel/Interrupts/IRQHandler.h>
+
+namespace Kernel {
+
+// See: https://www-inst.eecs.berkeley.edu/~cs150/Documents/ac97_r23.pdf
+// And: https://www.intel.com/content/dam/doc/manual/io-controller-hub-7-hd-audio-ac97-manual.pdf
+
+class AC97 final : public PCI::Device
+    , public IRQHandler
+    , public CharacterDevice {
+    friend class DeviceManagement;
+
+public:
+    static void detect();
+
+    virtual ~AC97() override;
+
+    // ^IRQHandler
+    virtual StringView purpose() const override { return class_name(); }
+
+    // ^CharacterDevice
+    virtual bool can_read(const OpenFileDescription&, size_t) const override { return false; }
+    virtual bool can_write(const OpenFileDescription&, size_t) const override { return true; }
+    virtual ErrorOr<void> ioctl(OpenFileDescription&, unsigned, Userspace<void*>) override;
+    virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
+    virtual ErrorOr<size_t> write(OpenFileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
+
+private:
+    enum NativeAudioMixerRegister : u8 {
+        Reset = 0x00,
+        SetMasterOutputVolume = 0x02,
+        SetPCMOutputVolume = 0x18,
+        ExtendedAudioID = 0x28,
+        PCMFrontDACRate = 0x2c,
+    };
+
+    enum ExtendedAudioMask : u16 {
+        VariableRatePCMAudio = 1 << 0,
+        Revision = 3 << 10,
+    };
+
+    enum AC97Revision : u8 {
+        Revision21OrEarlier = 0b00,
+        Revision22 = 0b01,
+        Revision23 = 0b10,
+    };
+
+    enum NativeAudioBusRegister : u8 {
+        PCMOutBufferDescriptorListBaseAddress = 0x10,
+        PCMOutCurrentIndex = 0x14,
+        PCMOutLastValidIndex = 0x15,
+        PCMOutStatus = 0x16,
+        PCMOutPrefetchedIndex = 0x1a,
+        PCMOutControl = 0x1b,
+        GlobalControl = 0x2c,
+    };
+
+    enum AudioStatusRegisterFlag : u16 {
+        DMAControllerHalted = 1 << 0,
+        CurrentEqualsLastValid = 1 << 1,
+        LastValidBufferCompletionInterrupt = 1 << 2,
+        BufferCompletionInterruptStatus = 1 << 3,
+        FIFOError = 1 << 4,
+    };
+
+    enum AudioControlRegisterFlag : u8 {
+        RunPauseBusMaster = 1 << 0,
+        ResetRegisters = 1 << 1,
+        FIFOErrorInterruptEnable = 1 << 3,
+        InterruptOnCompletionEnable = 1 << 4,
+    };
+
+    enum GlobalControlFlag : u32 {
+        GPIInterruptEnable = 1 << 0,
+        AC97ColdReset = 1 << 1,
+    };
+
+    enum Muted {
+        Yes,
+        No,
+    };
+
+    struct BufferDescriptorListEntry {
+        u32 buffer_pointer;
+        u32 control_and_length;
+    };
+
+    enum BufferDescriptorListEntryFlags : u32 {
+        BufferUnderrunPolicy = 1 << 30,
+        InterruptOnCompletion = 1u << 31,
+    };
+
+    AC97(PCI::DeviceIdentifier);
+
+    // ^IRQHandler
+    virtual bool handle_irq(const RegisterState&) override;
+
+    // ^CharacterDevice
+    virtual StringView class_name() const override { return "AC97"sv; }
+
+    void initialize();
+    void reset_pcm_out();
+    void set_master_output_volume(u8, u8, Muted);
+    void set_pcm_output_sample_rate(u16);
+    void set_pcm_output_volume(u8, u8, Muted);
+    void set_output_buffer_dma_lvi(u8);
+    void start_output_buffer_dma();
+
+    OwnPtr<Memory::Region> m_buffer_descriptor_list;
+    u8 m_buffer_descriptor_list_index = 0;
+    IOAddress m_io_mixer_base;
+    IOAddress m_io_bus_base;
+    WaitQueue m_irq_queue;
+    OwnPtr<Memory::Region> m_output_buffer;
+    bool m_output_buffer_dma_running = false;
+    u8 m_output_buffer_page_count = 4;
+    u8 m_output_buffer_page_index = 0;
+    u16 m_sample_rate = 44100;
+};
+
+}