#include <socks/pci.h>
#include <arch/ports.h>
#include <socks/libc/stdio.h>
#include "pci.h"

static void pci_scan_bus(pci_func_t f, int type, int bus, void *arg);

void pci_write_field(uint32_t device, int field, int size, uint32_t value)
{
	outportl(PCI_ADDRESS_PORT, pci_get_addr(device, field));
	outportl(PCI_VALUE_PORT, value);
}

uint32_t pci_read_field(uint32_t device, int field, int size)
{
	outportl(PCI_ADDRESS_PORT, pci_get_addr(device, field));

	if (size == 4) {
		uint32_t t = inportl(PCI_VALUE_PORT);
		return t;
	} else if (size == 2) {
		uint16_t t = inportw(PCI_VALUE_PORT + (field & 2));
		return t;
	} else if (size == 1) {
		uint8_t t = inportb(PCI_VALUE_PORT + (field & 3));
		return t;
	}

	return 0xFFFF;
}

uint32_t pci_device_read_field(struct device *dev, int field, int size)
{
	struct pci_device *pci_dev = dev->dev_bus_priv;
	if (!pci_dev) {
		return 0;
	}

	return pci_read_field(pci_box_device(pci_dev->pci_bus, pci_dev->pci_slot, pci_dev->pci_func), field, size);
}

void pci_device_write_field(struct device *dev, int field, int size, uint32_t value)
{
	struct pci_device *pci_dev = dev->dev_bus_priv;
	if (!pci_dev) {
		return;
	}

	pci_write_field(pci_box_device(pci_dev->pci_bus, pci_dev->pci_slot, pci_dev->pci_func), field, size, value);
}

uint16_t pci_find_type(uint32_t dev)
{
	return (pci_read_field(dev, PCI_REG_CLASS, 1) << 8) | pci_read_field(dev, PCI_REG_SUBCLASS, 1);
}

static void pci_scan_hit(pci_func_t f, uint32_t dev, void *arg)
{
	int dev_vend = (int)pci_read_field(dev, PCI_REG_VENDOR_ID, 2);
	int dev_dvid = (int)pci_read_field(dev, PCI_REG_DEVICE_ID, 2);

	f(dev, dev_vend, dev_dvid, arg);
}

static void pci_scan_func(pci_func_t f, int type, int bus, int slot, int func, void *arg)
{
	uint32_t dev = pci_box_device(bus, slot, func);
	if (type == -1 || type == pci_find_type(dev)) {
		pci_scan_hit(f, dev, arg);
	}

	if (pci_find_type(dev) == PCI_TYPE_BRIDGE) {
		pci_scan_bus(f, type, pci_read_field(dev, PCI_REG_SECONDARY_BUS, 1), arg);
	}
}

static void pci_scan_slot(pci_func_t f, int type, int bus, int slot, void *arg)
{
	uint32_t dev = pci_box_device(bus, slot, 0);
	if (pci_read_field(dev, PCI_REG_VENDOR_ID, 2) == PCI_NONE) {
		return;
	}

	pci_scan_func(f, type, bus, slot, 0, arg);
	if (!pci_read_field(dev, PCI_REG_HEADER_TYPE, 1)) {
		return;
	}

	for (int func = 1; func < 8; func++) {
		uint32_t dev = pci_box_device(bus, slot, func);
		if (pci_read_field(dev, PCI_REG_VENDOR_ID, 2) != PCI_NONE) {
			pci_scan_func(f, type, bus, slot, func, arg);
		}
	}
}

static void pci_scan_bus(pci_func_t f, int type, int bus, void *arg)
{
	for (int slot = 0; slot < 32; ++slot) {
		pci_scan_slot(f, type, bus, slot, arg);
	}
}

void pci_enumerate_devices(pci_func_t f, int type, void *arg)
{
	if ((pci_read_field(0, PCI_REG_HEADER_TYPE, 1) & 0x80) == 0) {
		pci_scan_bus(f, type, 0, arg);
		return;
	}

	int hit = 0;
	for (int func = 0; func < 8; ++func) {
		uint32_t dev = pci_box_device(0, 0, func);
		if (pci_read_field(dev, PCI_REG_VENDOR_ID, 2) == PCI_NONE) {
			break;
		}

		hit = 1;
		pci_scan_bus(f, type, func, arg);
	}

	if (hit) {
		return;
	}

	for (int bus = 0; bus < 256; ++bus) {
		for (int slot = 0; slot < 32; ++slot) {
			pci_scan_slot(f, type, bus, slot, arg);
		}
	}
}