#include <kernel/pci.h>
#include <kernel/io.h>

uint16_t pci_read_cfg(uint8_t bus, uint8_t slot, uint8_t func, uint8_t offset) {
    uint32_t address;
    uint32_t lbus  = (uint32_t)bus;
    uint32_t lslot = (uint32_t)slot;
    uint32_t lfunc = (uint32_t)func;
    uint16_t tmp = 0;

    // Create configuration address as per Figure 1
    address = (uint32_t)((lbus << 16) | (lslot << 11) |
            (lfunc << 8) | (offset & 0xFC) | ((uint32_t)0x80000000));

    outl(PCI_CONFIG_ADDR, address);

    tmp = (uint16_t)((inl(PCI_CONFIG_DATA) >> ((offset & 2) * 8)) & 0xFFFF);
    return tmp;
}