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serenity/Kernel/FileSystem/SysFS/Subsystems/Devices/Graphics/DisplayConnector/DeviceAttribute.cpp
Liav A b02ee664e7 Kernel: Get rid of *LockRefPtr in the SysFS filesystem code
To do this we also need to get rid of LockRefPtrs in the USB code as
well.
Most of the SysFS nodes are statically generated during boot and are not
mutated afterwards.

The same goes for general device code - once we generate the appropriate
SysFS nodes, we almost never mutate the node pointers afterwards, making
locking unnecessary.
2023-04-14 19:24:54 +02:00

86 lines
3 KiB
C++

/*
* Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Bus/PCI/API.h>
#include <Kernel/Bus/PCI/Access.h>
#include <Kernel/FileSystem/SysFS/Subsystems/Devices/Graphics/DisplayConnector/DeviceAttribute.h>
#include <Kernel/Sections.h>
namespace Kernel {
StringView DisplayConnectorAttributeSysFSComponent::name() const
{
switch (m_type) {
case Type::MutableModeSettingCapable:
return "mutable_mode_setting_capable"sv;
case Type::DoubleFrameBufferingCapable:
return "double_framebuffering_capable"sv;
case Type::FlushSupport:
return "flush_support"sv;
case Type::PartialFlushSupport:
return "partial_flush_support"sv;
case Type::RefreshRateSupport:
return "refresh_rate_support"sv;
case Type::EDID:
return "edid"sv;
default:
VERIFY_NOT_REACHED();
}
}
NonnullRefPtr<DisplayConnectorAttributeSysFSComponent> DisplayConnectorAttributeSysFSComponent::must_create(DisplayConnectorSysFSDirectory const& device_directory, Type type)
{
return adopt_ref(*new (nothrow) DisplayConnectorAttributeSysFSComponent(device_directory, type));
}
DisplayConnectorAttributeSysFSComponent::DisplayConnectorAttributeSysFSComponent(DisplayConnectorSysFSDirectory const& device_directory, Type type)
: SysFSComponent()
, m_device(device_directory.device({}))
, m_type(type)
{
}
ErrorOr<size_t> DisplayConnectorAttributeSysFSComponent::read_bytes(off_t offset, size_t count, UserOrKernelBuffer& buffer, OpenFileDescription*) const
{
auto blob = TRY(try_to_generate_buffer());
if ((size_t)offset >= blob->size())
return 0;
ssize_t nread = min(static_cast<off_t>(blob->size() - offset), static_cast<off_t>(count));
TRY(buffer.write(blob->data() + offset, nread));
return nread;
}
ErrorOr<NonnullOwnPtr<KBuffer>> DisplayConnectorAttributeSysFSComponent::try_to_generate_buffer() const
{
OwnPtr<KString> value;
switch (m_type) {
case Type::MutableModeSettingCapable:
value = TRY(KString::formatted("{:d}", m_device->mutable_mode_setting_capable()));
break;
case Type::DoubleFrameBufferingCapable:
value = TRY(KString::formatted("{:d}", m_device->double_framebuffering_capable()));
break;
case Type::FlushSupport:
value = TRY(KString::formatted("{:d}", m_device->flush_support()));
break;
case Type::PartialFlushSupport:
value = TRY(KString::formatted("{:d}", m_device->partial_flush_support()));
break;
case Type::RefreshRateSupport:
value = TRY(KString::formatted("{:d}", m_device->refresh_rate_support()));
break;
case Type::EDID: {
auto edid_buffer = TRY(m_device->get_edid());
return KBuffer::try_create_with_bytes("SysFS DisplayConnectorAttributeSysFSComponent EDID buffer"sv, edid_buffer.bytes());
}
default:
VERIFY_NOT_REACHED();
}
return KBuffer::try_create_with_bytes("SysFS DisplayConnectorAttributeSysFSComponent buffer"sv, value->view().bytes());
}
}