Chapter12- PCI Drivers
PCI Drivers The PCI bus achieves better performance by using a higher clock rate than ISA Each PCI peripheral is identified by a bus number, a device number, and a function number The PCI spec permits single system to host upto 256 buses, Since it is not sufficient the Linux now supports PCI domains Each PCI domain can host upto 256 buses Each bus host upto 32 devices Each device can be multifunction board. e.g. Audio device with CDROM drive with a maximum of 8 functions Each function can be identified at hardware level by a 16 bit address or key Device drivers in Linux don't need to deal with those binary address because they use specific data structure called pci_dev to act on the devices Bridges are special purpose peripherals whose task is joining two peripheral Overall layout of PCI system is a tree where each bus is connected to an upper layer bus, upto bus 0 at the root of the tree lspci is a part of PCI utils package and the layout information in /proc/pci and /proc/bus/pci...