45 строки
1,3 КиБ
Go
45 строки
1,3 КиБ
Go
//go:build avr
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package interrupt
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import "device"
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// State represents the previous global interrupt state.
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type State uint8
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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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// SREG is at I/O address 0x3f.
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return State(device.AsmFull(`
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in {}, 0x3f
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cli
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`, nil))
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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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// SREG is at I/O address 0x3f.
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device.AsmFull("out 0x3f, {state}", map[string]interface{}{
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"state": state,
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})
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}
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// In returns whether the system is currently in an interrupt.
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//
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// Warning: this always returns false on AVR, as there does not appear to be a
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// reliable way to determine whether we're currently running inside an interrupt
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// handler.
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func In() bool {
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return false
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}
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