go-packages/go-rpio
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Add IRQ enable/disable

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This commit is contained in:
Drahoslav 2018-12-01 05:25:08 +01:00
parent 579db243a0
commit 631591fc01
1 changed files with 46 additions and 11 deletions
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57
rpio.go
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@ -90,6 +90,7 @@ const (
clkOffset = 0x101000
pwmOffset = 0x20C000
spiOffset = 0x204000
intrOffset = 0x00B000
memLength = 4096
)
@ -99,6 +100,9 @@ var (
clkBase int64
pwmBase int64
spiBase int64
intrBase int64
irqsBackup uint64
)
func init() {
@ -107,6 +111,7 @@ func init() {
clkBase = base + clkOffset
pwmBase = base + pwmOffset
spiBase = base + spiOffset
intrBase = base + intrOffset
}
// Pin mode, a pin can be set in Input or Output, Clock or Pwm mode
@ -146,10 +151,12 @@ var (
clkMem []uint32
pwmMem []uint32
spiMem []uint32
intrMem []uint32
gpioMem8 []uint8
clkMem8 []uint8
pwmMem8 []uint8
spiMem8 []uint8
intrMem8 []uint8
)
// Set pin as Input
@ -584,6 +591,32 @@ func StartPwm() {
pwmMem[pwmCtlReg] |= pwen<<8 | pwen
}
// Enables given IRQs (by setting bit to 1 at intended position).
// See 'ARM peripherals interrupts table' in pheripherals datasheet.
// WARNING: you can corrupt your system, only use this if you know what you are doing.
func EnableIRQs(irqs uint64) {
const irqEnable1 = 0x210 / 4
const irqEnable2 = 0x214 / 4
intrMem[irqEnable1] = uint32(irqs) // IRQ 0..31
intrMem[irqEnable2] = uint32(irqs >> 32) // IRQ 32..63
}
// Disables given IRQs (by setting bit to 1 at intended position).
// See 'ARM peripherals interrupts table' in pheripherals datasheet.
// WARNING: you can corrupt your system, only use this if you know what you are doing.
func DisableIRQs(irqs uint64) {
const irqDisable1 = 0x21C / 4
const irqDisable2 = 0x220 / 4
intrMem[irqDisable1] = uint32(irqs) // IRQ 0..31
intrMem[irqDisable2] = uint32(irqs >> 32) // IRQ 32..63
}
func backupIRQs() {
const irqEnable1 = 0x210 / 4
const irqEnable2 = 0x214 / 4
irqsBackup = uint64(intrMem[irqEnable2])<<32 | uint64(intrMem[irqEnable1])
}
// Open and memory map GPIO memory range from /dev/mem .
// Some reflection magic is used to convert it to a unsafe []uint32 pointer
func Open() (err error) {
@ -627,6 +660,14 @@ func Open() (err error) {
return
}
// Memory map interruption registers to slice
intrMem, intrMem8, err = memMap(file.Fd(), intrBase)
if err != nil {
return
}
backupIRQs() // back up enabled IRQs, to restore it later
return nil
}
@ -653,18 +694,12 @@ func memMap(fd uintptr, base int64) (mem []uint32, mem8 []byte, err error) {
func Close() error {
memlock.Lock()
defer memlock.Unlock()
if err := syscall.Munmap(gpioMem8); err != nil {
return err
}
if err := syscall.Munmap(clkMem8); err != nil {
return err
}
if err := syscall.Munmap(pwmMem8); err != nil {
return err
}
if err := syscall.Munmap(spiMem8); err != nil {
return err
for _, mem8 := range [][]uint8{gpioMem8, clkMem8, pwmMem8, spiMem8, intrMem8} {
if err := syscall.Munmap(mem8); err != nil {
return err
}
}
EnableIRQs(irqsBackup) // Return IRQs to state where it was before - just to be nice
return nil
}