I am completely new to this PCI device driver so I just wanted to know that how kernel build pci_dev structure during pci initialization time. what are the pci function are being called

The sequence of routines that lead to pci device initialization. pci_legacy_init() -> pcibios_scan_root() -> pci_scan_child_bus()-> pci_scan_slot()-> pci_scan_single_device() ->pci_device_add()-> device_add(&dev->dev) -> bus_probe_device() -> device_attach() struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn) { struct pci_dev *dev; dev = pci_get_slot(bus, devfn); if (dev) { pci_dev_put(dev); return dev; } dev = pci_scan_device(bus, devfn); if (!dev) return NULL; pci_device_add(dev, bus); return dev; } /* * Read the config data for a PCI device, sanity-check it * and fill in the dev structure... */ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) { struct pci_dev *dev; u32 l; if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000)) return NULL; dev = pci_alloc_dev(bus); if (!dev) return NULL; dev->devfn = devfn; dev->vendor = l & 0xffff; dev->device = (l >> 16) & 0xffff; pci_set_of_node(dev); if (pci_setup_device(dev)) { pci_bus_put(dev->bus); kfree(dev); return NULL; } return dev; }