embd/gpiodriver.go

74 lines
1.3 KiB
Go

// Generic GPIO driver.
package embd
import (
"errors"
"fmt"
)
type pin interface {
Close() error
}
type gpioDriver struct {
pinMap PinMap
dpf func(n int) DigitalPin
apf func(n int) AnalogPin
initializedPins map[string]pin
}
func newGPIODriver(pinMap PinMap, dpf func(n int) DigitalPin, apf func(n int) AnalogPin) GPIODriver {
return &gpioDriver{
pinMap: pinMap,
dpf: dpf,
apf: apf,
initializedPins: map[string]pin{},
}
}
func (io *gpioDriver) DigitalPin(key interface{}) (DigitalPin, error) {
if io.dpf == nil {
return nil, errors.New("gpio: digital io not supported on this host")
}
pd, found := io.pinMap.Lookup(key, CapDigital)
if !found {
return nil, fmt.Errorf("gpio: could not find pin matching %v", key)
}
p := io.dpf(pd.DigitalLogical)
io.initializedPins[pd.ID] = p
return p, nil
}
func (io *gpioDriver) AnalogPin(key interface{}) (AnalogPin, error) {
if io.apf == nil {
return nil, errors.New("gpio: analog io not supported on this host")
}
pd, found := io.pinMap.Lookup(key, CapAnalog)
if !found {
return nil, fmt.Errorf("gpio: could not find pin matching %v", key)
}
p := io.apf(pd.AnalogLogical)
io.initializedPins[pd.ID] = p
return p, nil
}
func (io *gpioDriver) Close() error {
for _, p := range io.initializedPins {
if err := p.Close(); err != nil {
return err
}
}
return nil
}