/*
 * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <Kernel/PCI/Access.h>
#include <Kernel/PCI/IOAccess.h>

namespace Kernel {

static PCI::Access* s_access;

PCI::Access& PCI::Access::the()
{
    if (s_access == nullptr) {
        ASSERT_NOT_REACHED(); // We failed to initialize the PCI subsystem, so stop here!
    }
    return *s_access;
}

bool PCI::Access::is_initialized()
{
    return (s_access != nullptr);
}

PCI::Access::Access()
{
    s_access = this;
}

void PCI::Access::enumerate_functions(int type, u8 bus, u8 slot, u8 function, Function<void(Address, ID)>& callback)
{
    Address address(0, bus, slot, function);
    if (type == -1 || type == read_type(address))
        callback(address, { read16_field(address, PCI_VENDOR_ID), read16_field(address, PCI_DEVICE_ID) });
    if (read_type(address) == PCI_TYPE_BRIDGE) {
        u8 secondary_bus = read8_field(address, PCI_SECONDARY_BUS);
#ifdef PCI_DEBUG
        klog() << "PCI: Found secondary bus: " << secondary_bus;
#endif
        ASSERT(secondary_bus != bus);
        enumerate_bus(type, secondary_bus, callback);
    }
}

void PCI::Access::enumerate_slot(int type, u8 bus, u8 slot, Function<void(Address, ID)>& callback)
{
    Address address(0, bus, slot, 0);
    if (read16_field(address, PCI_VENDOR_ID) == PCI_NONE)
        return;
    enumerate_functions(type, bus, slot, 0, callback);
    if (!(read8_field(address, PCI_HEADER_TYPE) & 0x80))
        return;
    for (u8 function = 1; function < 8; ++function) {
        Address address(0, bus, slot, function);
        if (read16_field(address, PCI_VENDOR_ID) != PCI_NONE)
            enumerate_functions(type, bus, slot, function, callback);
    }
}

PCI::ID PCI::Access::get_id(Address address)
{
    return { read16_field(address, PCI_VENDOR_ID), read16_field(address, PCI_DEVICE_ID) };
}

void PCI::Access::enumerate_bus(int type, u8 bus, Function<void(Address, ID)>& callback)
{
    for (u8 slot = 0; slot < 32; ++slot)
        enumerate_slot(type, bus, slot, callback);
}

void PCI::Access::enable_bus_mastering(Address address)
{
    auto value = read16_field(address, PCI_COMMAND);
    value |= (1 << 2);
    value |= (1 << 0);
    write16_field(address, PCI_COMMAND, value);
}

void PCI::Access::disable_bus_mastering(Address address)
{
    auto value = read16_field(address, PCI_COMMAND);
    value &= ~(1 << 2);
    value |= (1 << 0);
    write16_field(address, PCI_COMMAND, value);
}

namespace PCI {

    void enumerate_all(Function<void(Address, ID)> callback)
    {
        PCI::Access::the().enumerate_all(callback);
    }

    void raw_access(Address address, u32 field, size_t access_size, u32 value)
    {
        ASSERT(access_size != 0);
        if (access_size == 1) {
            PCI::Access::the().write8_field(address, field, value);
            return;
        }
        if (access_size == 2) {
            PCI::Access::the().write16_field(address, field, value);
            return;
        }
        if (access_size == 4) {
            PCI::Access::the().write32_field(address, field, value);
            return;
        }
        ASSERT_NOT_REACHED();
    }

    ID get_id(Address address)
    {
        return PCI::Access::the().get_id(address);
    }

    void enable_interrupt_line(Address address)
    {
        PCI::Access::the().enable_interrupt_line(address);
    }
    void disable_interrupt_line(Address address)
    {
        PCI::Access::the().disable_interrupt_line(address);
    }

    u8 get_interrupt_line(Address address)
    {
        return PCI::Access::the().get_interrupt_line(address);
    }
    u32 get_BAR0(Address address)
    {
        return PCI::Access::the().get_BAR0(address);
    }
    u32 get_BAR1(Address address)
    {
        return PCI::Access::the().get_BAR1(address);
    }
    u32 get_BAR2(Address address)
    {
        return PCI::Access::the().get_BAR2(address);
    }
    u32 get_BAR3(Address address)
    {
        return PCI::Access::the().get_BAR3(address);
    }
    u32 get_BAR4(Address address)
    {
        return PCI::Access::the().get_BAR4(address);
    }
    u32 get_BAR5(Address address)
    {
        return PCI::Access::the().get_BAR5(address);
    }
    u8 get_revision_id(Address address)
    {
        return PCI::Access::the().get_revision_id(address);
    }
    u8 get_subclass(Address address)
    {
        return PCI::Access::the().get_subclass(address);
    }
    u8 get_class(Address address)
    {
        return PCI::Access::the().get_class(address);
    }
    u16 get_subsystem_id(Address address)
    {
        return PCI::Access::the().get_subsystem_id(address);
    }
    u16 get_subsystem_vendor_id(Address address)
    {
        return PCI::Access::the().get_subsystem_vendor_id(address);
    }
    void enable_bus_mastering(Address address)
    {
        PCI::Access::the().enable_bus_mastering(address);
    }
    void disable_bus_mastering(Address address)
    {
        PCI::Access::the().disable_bus_mastering(address);
    }
    size_t get_BAR_Space_Size(Address address, u8 bar_number)
    {
        return PCI::Access::the().get_BAR_Space_Size(address, bar_number);
    }
}

}