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Kernel: Implement AC97 audio device driver

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This commit is contained in:
Jelle Raaijmakers 2021-11-23 01:13:02 +01:00 • committed by Andreas Kling
parent 1aafb6cd23
commit 7a2a0c1052
5 changed files with 403 additions and 0 deletions
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9
Kernel/Bus/PCI/Definitions.h
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@ -64,6 +64,7 @@ static constexpr size_t memory_range_per_bus = mmio_device_space_size * to_under
// Taken from https://pcisig.com/sites/default/files/files/PCI_Code-ID_r_1_11__v24_Jan_2019.pdf
enum class ClassID {
MassStorage = 0x1,
Multimedia = 0x4,
Bridge = 0x6,
};
@ -79,6 +80,14 @@ enum class SATAProgIF {
}
namespace Multimedia {
enum class SubclassID {
AudioController = 0x1,
};
}
namespace Bridge {
enum class SubclassID {

1
Kernel/CMakeLists.txt
View file

@ -43,6 +43,7 @@ set(KERNEL_SOURCES
CommandLine.cpp
Coredump.cpp
Devices/AsyncDeviceRequest.cpp
Devices/Audio/AC97.cpp
Devices/Audio/SB16.cpp
Devices/BlockDevice.cpp
Devices/CharacterDevice.cpp

258
Kernel/Devices/Audio/AC97.cpp Normal file
View file

@ -0,0 +1,258 @@
/*
* Copyright (c) 2021, Jelle Raaijmakers <jelle@gmta.nl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Devices/Audio/AC97.h>
#include <Kernel/Devices/DeviceManagement.h>
#include <Kernel/Memory/AnonymousVMObject.h>
#include <LibC/sys/ioctl_numbers.h>
namespace Kernel {
static constexpr int buffer_descriptor_list_max_entries = 32;
static ErrorOr<OwnPtr<Memory::Region>> allocate_physical_buffer(size_t size, StringView name)
{
auto vmobject = TRY(Memory::AnonymousVMObject::try_create_physically_contiguous_with_size(Memory::page_round_up(size)));
return TRY(MM.allocate_kernel_region_with_vmobject(move(vmobject), vmobject->size(), name, Memory::Region::Access::Write));
}
UNMAP_AFTER_INIT void AC97::detect()
{
PCI::enumerate([&](PCI::DeviceIdentifier const& device_identifier) {
// Only consider PCI audio controllers
if (device_identifier.class_code().value() != to_underlying(PCI::ClassID::Multimedia)
|| device_identifier.subclass_code().value() != to_underlying(PCI::Multimedia::SubclassID::AudioController))
return;
dbgln("AC97: found audio controller at {}", device_identifier.address());
auto device_or_error = DeviceManagement::try_create_device<AC97>(device_identifier);
if (device_or_error.is_error()) {
dbgln("AC97: failed to initialize device {}", device_identifier.address());
return;
}
DeviceManagement::the().attach_audio_device(device_or_error.release_value());
});
}
UNMAP_AFTER_INIT AC97::AC97(PCI::DeviceIdentifier pci_device_identifier)
: PCI::Device(pci_device_identifier.address())
, IRQHandler(pci_device_identifier.interrupt_line().value())
, CharacterDevice(42, 42)
, m_io_mixer_base(PCI::get_BAR0(pci_address()) & ~1)
, m_io_bus_base(PCI::get_BAR1(pci_address()) & ~1)
{
initialize();
}
UNMAP_AFTER_INIT AC97::~AC97()
{
}
bool AC97::handle_irq(RegisterState const&)
{
auto pcm_out_status_register = m_io_bus_base.offset(NativeAudioBusRegister::PCMOutStatus);
auto pcm_out_status = pcm_out_status_register.in<u16>();
bool is_dma_halted = (pcm_out_status & AudioStatusRegisterFlag::DMAControllerHalted) > 0;
bool is_completion_interrupt = (pcm_out_status & AudioStatusRegisterFlag::BufferCompletionInterruptStatus) > 0;
bool is_fifo_error = (pcm_out_status & AudioStatusRegisterFlag::FIFOError) > 0;
VERIFY(is_completion_interrupt);
VERIFY(!is_fifo_error);
// On interrupt, we need to reset PCM interrupt flags by setting their bits
pcm_out_status = AudioStatusRegisterFlag::LastValidBufferCompletionInterrupt
| AudioStatusRegisterFlag::BufferCompletionInterruptStatus
| AudioStatusRegisterFlag::FIFOError;
pcm_out_status_register.out(pcm_out_status);
// Stop the DMA engine if we're through with the buffer and no one is waiting
if (is_dma_halted && m_irq_queue.is_empty()) {
reset_pcm_out();
} else {
m_irq_queue.wake_all();
}
return true;
}
UNMAP_AFTER_INIT void AC97::initialize()
{
dbgln("AC97 @ {}: mixer base: {:#04x}", pci_address(), m_io_mixer_base.get());
dbgln("AC97 @ {}: bus base: {:#04x}", pci_address(), m_io_bus_base.get());
enable_pin_based_interrupts();
PCI::enable_bus_mastering(pci_address());
// Bus cold reset, enable interrupts
auto control = m_io_bus_base.offset(NativeAudioBusRegister::GlobalControl).in<u32>();
control |= GlobalControlFlag::GPIInterruptEnable;
control |= GlobalControlFlag::AC97ColdReset;
m_io_bus_base.offset(NativeAudioBusRegister::GlobalControl).out<u32>(control);
// Reset mixer
m_io_mixer_base.offset(NativeAudioMixerRegister::Reset).out<u16>(1);
// Verify extended capabilities
auto extended_audio_id = m_io_mixer_base.offset(NativeAudioMixerRegister::ExtendedAudioID).in<u16>();
VERIFY((extended_audio_id & ExtendedAudioMask::VariableRatePCMAudio) == 1);
VERIFY((extended_audio_id & ExtendedAudioMask::Revision) >> 10 == AC97Revision::Revision23);
// Left and right volume of 0 means attenuation of 0 dB
set_master_output_volume(0, 0, Muted::No);
set_pcm_output_volume(0, 0, Muted::No);
set_pcm_output_sample_rate(m_sample_rate);
reset_pcm_out();
enable_irq();
}
ErrorOr<void> AC97::ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg)
{
switch (request) {
case SOUNDCARD_IOCTL_GET_SAMPLE_RATE: {
auto output = static_ptr_cast<u16*>(arg);
return copy_to_user(output, &m_sample_rate);
}
case SOUNDCARD_IOCTL_SET_SAMPLE_RATE: {
auto sample_rate_value = static_cast<u16>(arg.ptr());
if (sample_rate_value == 0)
return EINVAL;
if (m_sample_rate != sample_rate_value)
set_pcm_output_sample_rate(sample_rate_value);
return {};
}
default:
return EINVAL;
}
}
ErrorOr<size_t> AC97::read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t)
{
return 0;
}
void AC97::reset_pcm_out()
{
auto pcm_out_control_register = m_io_bus_base.offset(NativeAudioBusRegister::PCMOutControl);
pcm_out_control_register.out(AudioControlRegisterFlag::ResetRegisters);
while ((pcm_out_control_register.in<u8>() & AudioControlRegisterFlag::ResetRegisters) > 0)
IO::delay(50);
m_output_buffer_dma_running = false;
m_buffer_descriptor_list_index = 0;
dbgln("AC97 @ {}: PCM out is reset", pci_address());
}
void AC97::set_master_output_volume(u8 left_channel, u8 right_channel, Muted mute)
{
u16 volume_value = ((right_channel & 63) << 0)
| ((left_channel & 63) << 8)
| ((mute == Muted::Yes ? 1 : 0) << 15);
m_io_mixer_base.offset(NativeAudioMixerRegister::SetMasterOutputVolume).out(volume_value);
}
void AC97::set_output_buffer_dma_lvi(u8 last_valid_index)
{
auto buffer_address = static_cast<u32>(m_buffer_descriptor_list->physical_page(0)->paddr().get());
m_io_bus_base.offset(NativeAudioBusRegister::PCMOutBufferDescriptorListBaseAddress).out(buffer_address);
m_io_bus_base.offset(NativeAudioBusRegister::PCMOutLastValidIndex).out<u8>(last_valid_index);
}
void AC97::set_pcm_output_sample_rate(u16 sample_rate)
{
auto pcm_front_dac_rate_register = m_io_mixer_base.offset(NativeAudioMixerRegister::PCMFrontDACRate);
pcm_front_dac_rate_register.out(sample_rate);
m_sample_rate = pcm_front_dac_rate_register.in<u16>();
dbgln("AC97 @ {}: PCM front DAC rate set to {} Hz", pci_address(), m_sample_rate);
}
void AC97::set_pcm_output_volume(u8 left_channel, u8 right_channel, Muted mute)
{
u16 volume_value = ((right_channel & 31) << 0)
| ((left_channel & 31) << 8)
| ((mute == Muted::Yes ? 1 : 0) << 15);
m_io_mixer_base.offset(NativeAudioMixerRegister::SetPCMOutputVolume).out(volume_value);
}
void AC97::start_output_buffer_dma()
{
dbgln("AC97 @ {}: starting DMA engine", pci_address());
auto pcm_out_control_register = m_io_bus_base.offset(NativeAudioBusRegister::PCMOutControl);
auto pcm_out_control = pcm_out_control_register.in<u8>();
pcm_out_control |= AudioControlRegisterFlag::RunPauseBusMaster;
pcm_out_control |= AudioControlRegisterFlag::FIFOErrorInterruptEnable;
pcm_out_control |= AudioControlRegisterFlag::InterruptOnCompletionEnable;
pcm_out_control_register.out(pcm_out_control);
m_output_buffer_dma_running = true;
}
ErrorOr<size_t> AC97::write(OpenFileDescription&, u64, UserOrKernelBuffer const& data, size_t length)
{
VERIFY(length <= PAGE_SIZE);
if (!m_output_buffer) {
m_output_buffer = TRY(allocate_physical_buffer(m_output_buffer_page_count * PAGE_SIZE, "AC97 Output buffer"sv));
}
if (!m_buffer_descriptor_list) {
constexpr size_t buffer_descriptor_list_size = buffer_descriptor_list_max_entries * sizeof(BufferDescriptorListEntry);
m_buffer_descriptor_list = TRY(allocate_physical_buffer(buffer_descriptor_list_size, "AC97 Buffer Descriptor List"sv));
}
cli();
// Block until we can write into an unused buffer
do {
auto pcm_out_status = m_io_bus_base.offset(NativeAudioBusRegister::PCMOutStatus).in<u16>();
auto is_dma_controller_halted = (pcm_out_status & AudioStatusRegisterFlag::DMAControllerHalted) > 0;
auto current_index = m_io_bus_base.offset(NativeAudioBusRegister::PCMOutCurrentIndex).in<u8>();
auto last_valid_index = m_io_bus_base.offset(NativeAudioBusRegister::PCMOutLastValidIndex).in<u8>();
auto head_distance = static_cast<int>(last_valid_index) - current_index;
if (head_distance < 0)
head_distance += buffer_descriptor_list_max_entries;
if (!is_dma_controller_halted)
++head_distance;
if (head_distance < m_output_buffer_page_count)
break;
m_irq_queue.wait_forever("AC97"sv);
} while (m_output_buffer_dma_running);
sti();
// Copy data from userspace into one of our buffers
TRY(data.read(m_output_buffer->vaddr_from_page_index(m_output_buffer_page_index).as_ptr(), length));
if (!m_output_buffer_dma_running) {
reset_pcm_out();
}
// Write the next entry to the buffer descriptor list
u16 number_of_samples = length / sizeof(u16);
auto list_entries = reinterpret_cast<BufferDescriptorListEntry*>(m_buffer_descriptor_list->vaddr().get());
auto list_entry = &list_entries[m_buffer_descriptor_list_index];
list_entry->buffer_pointer = static_cast<u32>(m_output_buffer->physical_page(m_output_buffer_page_index)->paddr().get());
list_entry->control_and_length = number_of_samples | BufferDescriptorListEntryFlags::InterruptOnCompletion;
set_output_buffer_dma_lvi(m_buffer_descriptor_list_index);
if (!m_output_buffer_dma_running) {
start_output_buffer_dma();
}
m_output_buffer_page_index = (m_output_buffer_page_index + 1) % m_output_buffer_page_count;
m_buffer_descriptor_list_index = (m_buffer_descriptor_list_index + 1) % buffer_descriptor_list_max_entries;
return length;
}
}

133
Kernel/Devices/Audio/AC97.h Normal file
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@ -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;
};
}

2
Kernel/init.cpp
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@ -13,6 +13,7 @@
#include <Kernel/Bus/VirtIO/Device.h>
#include <Kernel/CMOS.h>
#include <Kernel/CommandLine.h>
#include <Kernel/Devices/Audio/AC97.h>
#include <Kernel/Devices/Audio/SB16.h>
#include <Kernel/Devices/DeviceManagement.h>
#include <Kernel/Devices/FullDevice.h>
@ -319,6 +320,7 @@ void init_stage2(void*)
PTYMultiplexer::initialize();
SB16::try_detect_and_create();
AC97::detect();
StorageManagement::the().initialize(kernel_command_line().root_device(), kernel_command_line().is_force_pio());
if (VirtualFileSystem::the().mount_root(StorageManagement::the().root_filesystem()).is_error()) {