PCI_cfg_index.c

// ===========================================================================================================================================================================
// Convert PCI(bus:device.function,offset) to uint32_t array index
uint32_t PCI_cfg_index(unsigned int Bus, unsigned int Device, unsigned int Function, unsigned int Offset)
{
    uint32_t byteaddress;
    uint32_t index;
    assert (Device >= 0);
    assert (Function >= 0);
    assert (Offset >= 0);
    assert (Device < (1<<5));
    assert (Function < (1<<3));
    assert (Offset < (1<<12));
    byteaddress = (Bus<<20) | (Device<<15) | (Function<<12) | Offset;
    index = byteaddress / 4;
    return ( index );
}