centos man page for pci_bus_find_capability

PCI_BUS_FIND_CAPABIL(9) 					Hardware Interfaces					   PCI_BUS_FIND_CAPABIL(9)

NAME
       pci_bus_find_capability - query for devices' capabilities

SYNOPSIS
       int pci_bus_find_capability(struct pci_bus * bus, unsigned int devfn, int cap);

ARGUMENTS
       bus
	   the PCI bus to query

       devfn
	   PCI device to query

       cap
	   capability code

DESCRIPTION
       Like pci_find_capability but works for pci devices that do not have a pci_dev structure set up yet.

       Returns the address of the requested capability structure within the device's PCI configuration space or 0 in case the device does not
       support it.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						   PCI_BUS_FIND_CAPABIL(9)