Trait InterruptService

pub trait InterruptService {
    // Required method
    unsafe fn service_interrupt(&self, interrupt: u32) -> bool;
}

Interface for handling interrupts on a hardware chip.

Each board must construct an implementation of this trait to handle specific interrupts. When an interrupt (identified by number) has triggered and should be handled, the implementation of this trait will be called with the interrupt number. The implementation can then handle the interrupt, or return false to signify that it does not know how to handle the interrupt.

This functionality is given this InterruptService interface so that multiple objects can be chained together to handle interrupts for a chip. This is useful for code organization and removing the need for duplication when multiple variations of a specific microcontroller exist. Then a shared, base object can handle most interrupts, and variation-specific objects can handle the variation-specific interrupts.

To simplify structuring the Rust code when using InterruptService, the interrupt number should be passed “top-down”. That is, an interrupt to be handled will first be passed to the InterruptService object that is most specific. If that object cannot handle the interrupt, then it should maintain a reference to the second most specific object, and return by calling to that object to handle the interrupt. This continues until the base object handles the interrupt or decides that the chip does not know how to handle the interrupt. For example, consider a nRF52840 chip that depends on the nRF52 crate. If both have specific interrupts they know how to handle, the flow would look like:

          +---->nrf52840_peripherals
          |        |
          |        |
          |        v
kernel-->nrf52     nrf52_peripherals

where the kernel instructs the nrf52 crate to handle interrupts, and if there is an interrupt ready then that interrupt is passed through the InterruptService objects until something can service it.

Required Methods

unsafe fn service_interrupt(&self, interrupt: u32) -> bool

Service an interrupt, if supported by this chip. If this interrupt number is not supported, return false.

Implementors