62 строки
2 КиБ
Go
62 строки
2 КиБ
Go
//go:build cortexm
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package interrupt
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import (
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"device/arm"
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)
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// Enable enables this interrupt. Right after calling this function, the
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// interrupt may be invoked if it was already pending.
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func (irq Interrupt) Enable() {
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arm.EnableIRQ(uint32(irq.num))
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}
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// Disable disables this interrupt.
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func (irq Interrupt) Disable() {
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arm.DisableIRQ(uint32(irq.num))
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}
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// SetPriority sets the interrupt priority for this interrupt. A lower number
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// means a higher priority. Additionally, most hardware doesn't implement all
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// priority bits (only the uppoer bits).
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//
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// Examples: 0xff (lowest priority), 0xc0 (low priority), 0x00 (highest possible
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// priority).
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func (irq Interrupt) SetPriority(priority uint8) {
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arm.SetPriority(uint32(irq.num), uint32(priority))
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}
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// State represents the previous global interrupt state.
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type State uintptr
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// Disable disables all interrupts and returns the previous interrupt state. It
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// can be used in a critical section like this:
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//
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// state := interrupt.Disable()
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// // critical section
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// interrupt.Restore(state)
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//
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// Critical sections can be nested. Make sure to call Restore in the same order
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// as you called Disable (this happens naturally with the pattern above).
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func Disable() (state State) {
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return State(arm.DisableInterrupts())
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}
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// Restore restores interrupts to what they were before. Give the previous state
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// returned by Disable as a parameter. If interrupts were disabled before
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// calling Disable, this will not re-enable interrupts, allowing for nested
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// cricital sections.
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func Restore(state State) {
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arm.EnableInterrupts(uintptr(state))
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}
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// In returns whether the system is currently in an interrupt.
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func In() bool {
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// The VECTACTIVE field gives the instruction vector that is currently
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// active (in handler mode), or 0 if not in an interrupt.
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// Documentation:
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// https://developer.arm.com/documentation/dui0497/a/cortex-m0-peripherals/system-control-block/interrupt-control-and-state-register
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vectactive := uint8(arm.SCB.ICSR.Get())
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return vectactive != 0
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}
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