Peripheral Port Drivers
Drivers that represent ports, buses, and transport relationships for connected peripherals.
A port is a boundary
A port or bus driver represents a transport relationship and coordinates discovery, addressing, power, and transfers for devices connected through it. It may sit below class and function drivers.
Discovery is a shared job
The port layer can enumerate devices and expose descriptors or identifiers. Higher layers use that evidence to create device functions rather than treating every peripheral as an anonymous stream of bytes.
Transport is not function
USB, PCI, serial, and other transports carry different device classes. A port driver handles transport conventions, while a function driver represents what the peripheral does.
Shared ownership matters
Ports coordinate bandwidth, addresses, power, and transfer queues among multiple functions. Those resources explain why a peripheral driver cannot be understood independently of its bus.
Reference facts
- Primary role
- Discovery and transport coordination at a port or bus boundary.
- Relationship
- Port, class, and function layers can all participate in one peripheral stack.
Questions and answers
Is a port driver the driver for every connected device?
It can provide shared transport behavior, while class or function drivers represent individual device capabilities.
Why are descriptors important at a port?
They provide structured identity, interfaces, endpoints, and capability information for the host to interpret.