github.com/tinygo-org/tinygo@v0.31.3-0.20240404173401-90b0bf646c27/src/runtime/interrupt/interrupt_cortexm.go (about) 1 //go:build cortexm 2 3 package interrupt 4 5 import ( 6 "device/arm" 7 ) 8 9 // Enable enables this interrupt. Right after calling this function, the 10 // interrupt may be invoked if it was already pending. 11 func (irq Interrupt) Enable() { 12 arm.EnableIRQ(uint32(irq.num)) 13 } 14 15 // Disable disables this interrupt. 16 func (irq Interrupt) Disable() { 17 arm.DisableIRQ(uint32(irq.num)) 18 } 19 20 // SetPriority sets the interrupt priority for this interrupt. A lower number 21 // means a higher priority. Additionally, most hardware doesn't implement all 22 // priority bits (only the uppoer bits). 23 // 24 // Examples: 0xff (lowest priority), 0xc0 (low priority), 0x00 (highest possible 25 // priority). 26 func (irq Interrupt) SetPriority(priority uint8) { 27 arm.SetPriority(uint32(irq.num), uint32(priority)) 28 } 29 30 // State represents the previous global interrupt state. 31 type State uintptr 32 33 // Disable disables all interrupts and returns the previous interrupt state. It 34 // can be used in a critical section like this: 35 // 36 // state := interrupt.Disable() 37 // // critical section 38 // interrupt.Restore(state) 39 // 40 // Critical sections can be nested. Make sure to call Restore in the same order 41 // as you called Disable (this happens naturally with the pattern above). 42 func Disable() (state State) { 43 return State(arm.DisableInterrupts()) 44 } 45 46 // Restore restores interrupts to what they were before. Give the previous state 47 // returned by Disable as a parameter. If interrupts were disabled before 48 // calling Disable, this will not re-enable interrupts, allowing for nested 49 // cricital sections. 50 func Restore(state State) { 51 arm.EnableInterrupts(uintptr(state)) 52 } 53 54 // In returns whether the system is currently in an interrupt. 55 func In() bool { 56 // The VECTACTIVE field gives the instruction vector that is currently 57 // active (in handler mode), or 0 if not in an interrupt. 58 // Documentation: 59 // https://developer.arm.com/documentation/dui0497/a/cortex-m0-peripherals/system-control-block/interrupt-control-and-state-register 60 vectactive := uint8(arm.SCB.ICSR.Get()) 61 return vectactive != 0 62 }