#include <lcrash/pci/pci.h>

#include <lcrash/mm/virt.h>
#include <lcrash/acpi/acpi.h>
#include <lcrash/debug/debug.h>
#include <lcrash/driver/sysbus.h>

bool PciIsPresent   = false;
bool PciSupportsECM = false;

void* PciBusses[256] = {};

void PciScanDevice(u32 Bus, u32 Device) {
	struct PciConfigurationSpaceHeader* DeviceHeader = (struct PciConfigurationSpaceHeader*)(PciBusses[Bus] + Device * 0x800);

	// Is a device connected here?
	if (DeviceHeader->VendorID != 0xFFFF) {
		while (1) {}
	}
}

void PciScanBus(u32 Bus) {
	// Scan bus devices
	for (int i = 0; i < 32; i++) PciScanDevice(Bus, i);
}

void PciInitialize() {	
	// Try to figure out if we have PCIe
	if (!AcpiPresent()) Panic("Failed to initialize PCI"); 
	
	struct AcpiMCFG* BridgeTable = AcpiGetTable("MCFG");

	// Guess not
	if (BridgeTable == NULL) Panic("Failed to find PCI bridge table");

	// Take our pcie bridges
	s32 Length = (BridgeTable->Header.Length - 44) / 16;
	for (int i = 0; i < Length; i++) {
		// Identity map our busses because linux doesn't do it for us
		VmemMapMemory(
			BridgeTable->Bridges[i].Address, BridgeTable->Bridges[i].Address,
			(BridgeTable->Bridges[i].EndBus - BridgeTable->Bridges[i].StartBus) * 0x100000
		);

		for (int Bus = BridgeTable->Bridges[i].StartBus; Bus < BridgeTable->Bridges[i].EndBus; Bus++) {
			PciBusses[Bus] = BridgeTable->Bridges[i].Address + (Bus - BridgeTable->Bridges[i].StartBus) * 0x100000;
		}
	}
	
	// Scan the root bus
	PciScanBus(0);

	return;
}

bool PciPresent()  { return PciIsPresent; }
bool PciePresent() { return PciSupportsECM; }