The new interfaces are meant to gradually replace the existing
Gpio_session interface.
- Each session refers to a single pin.
- The session types distiguish the direction of the signal as input or
output.
- Pin coordinates can be selected via session labels.
- GPIO interrupts are covered by the regular IRQ session interface.
The interfaces are accompanied by framework utilities and interfaces:
- os/pin_driver.h
- pin_control_session/component.h
- pin_state_session/component.h
These headers relieve GPIO drivers from implementing boilerplate code by
providing device-agnostic portions. The A64 pio driver serves as
reference for using those utilities.
https://github.com/nfeske/genode-allwinner/tree/master/src/drivers/pin/a64Fixes#4315
