Kernel/Bus/USB/USBTransfer.cpp


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/*
 * Copyright (c) 2021, Jesse Buhagiar <jooster669@gmail.com>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#include <Kernel/Bus/USB/USBTransfer.h>
#include <Kernel/Memory/MemoryManager.h>

namespace Kernel::USB {

ErrorOr<NonnullRefPtr<Transfer>> Transfer::try_create(Pipe& pipe, u16 length)
{
    // Initialize data buffer for transfer
    // This will definitely need to be refactored in the future, I doubt this will scale well...
    auto region = TRY(MM.allocate_kernel_region(PAGE_SIZE, "USB Transfer Buffer", Memory::Region::Access::ReadWrite));
    return adopt_nonnull_ref_or_enomem(new (nothrow) Transfer(pipe, length, move(region)));
}

Transfer::Transfer(Pipe& pipe, u16 len, NonnullOwnPtr<Memory::Region> data_buffer)
    : m_pipe(pipe)
    , m_data_buffer(move(data_buffer))
    , m_transfer_data_size(len)
{
}

Transfer::~Transfer() = default;

void Transfer::set_setup_packet(const USBRequestData& request)
{
    // Kind of a nasty hack... Because the kernel isn't in the business
    // of handing out physical pointers that we can directly write to,
    // we set the address of the setup packet to be the first 8 bytes of
    // the data buffer, which we then set to the physical address.
    auto* request_data = reinterpret_cast<USBRequestData*>(buffer().as_ptr());

    request_data->request_type = request.request_type;
    request_data->request = request.request;
    request_data->value = request.value;
    request_data->index = request.index;
    request_data->length = request.length;

    m_request = request;
}

}