121 lines
2.6 KiB
Go
121 lines
2.6 KiB
Go
package rpi
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"sync"
|
|
|
|
"github.com/warthog618/gpiod"
|
|
)
|
|
|
|
const (
|
|
// DefaultChipName to try to use if one is not provided
|
|
DefaultChipName = "gpiochip0"
|
|
)
|
|
|
|
var (
|
|
// ErrLineAlreadyRequested denotes that the requested line is not available because it has already been requested and not Closed
|
|
ErrLineAlreadyRequested = errors.New("line has already been requested")
|
|
|
|
// ErrLineNotRequested denotes that the given line cannot be acted on because it was not previously requested
|
|
ErrLineNotRequested = errors.New("line was not previously requested")
|
|
)
|
|
|
|
// ManagerConfig configuration for a Manager
|
|
type ManagerConfig struct {
|
|
ChipName string
|
|
}
|
|
|
|
// GetChipName from the config
|
|
func (mc *ManagerConfig) GetChipName() string {
|
|
if mc.ChipName == "" {
|
|
return DefaultChipName
|
|
}
|
|
|
|
return mc.ChipName
|
|
}
|
|
|
|
// Manager for overarching raspberry pi GPIO management
|
|
type Manager struct {
|
|
config *ManagerConfig
|
|
chip *gpiod.Chip
|
|
lines map[int]*gpiod.Line
|
|
linesLock sync.Mutex
|
|
}
|
|
|
|
// NewManager creates a new Manager instance for the given config
|
|
func NewManager(config ManagerConfig) (*Manager, error) {
|
|
chip, err := gpiod.NewChip(config.GetChipName())
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to open GPIO chip %s: %w", config.GetChipName(), err)
|
|
}
|
|
|
|
return &Manager{
|
|
config: &config,
|
|
chip: chip,
|
|
lines: make(map[int]*gpiod.Line),
|
|
}, nil
|
|
}
|
|
|
|
// GetBasicLight for the given pin if available
|
|
func (m *Manager) GetBasicLight(pin int) (*BasicLight, error) {
|
|
line, err := m.requestLine(pin)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &BasicLight{
|
|
pin: pin,
|
|
line: line,
|
|
manager: m,
|
|
}, nil
|
|
}
|
|
|
|
func (m *Manager) requestLine(pin int) (*gpiod.Line, error) {
|
|
m.linesLock.Lock()
|
|
defer m.linesLock.Unlock()
|
|
|
|
_, exists := m.lines[pin]
|
|
if exists {
|
|
return nil, fmt.Errorf("%w pin %d", ErrLineAlreadyRequested, pin)
|
|
}
|
|
|
|
line, err := m.chip.RequestLine(pin, gpiod.AsOutput(0))
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to request line for pin %d: %w", pin, err)
|
|
}
|
|
|
|
m.lines[pin] = line
|
|
|
|
return line, nil
|
|
}
|
|
|
|
func (m *Manager) closeLine(pin int) error {
|
|
m.linesLock.Lock()
|
|
defer m.linesLock.Unlock()
|
|
|
|
return m.closeLineHelper(pin)
|
|
}
|
|
|
|
func (m *Manager) closeLineHelper(pin int) error {
|
|
line := m.lines[pin]
|
|
if line == nil {
|
|
return fmt.Errorf("%w pin %d", ErrLineNotRequested, pin)
|
|
}
|
|
|
|
delete(m.lines, pin)
|
|
|
|
return line.Close()
|
|
}
|
|
|
|
// Close this Manager and all of its associated lines
|
|
func (m *Manager) Close() error {
|
|
m.linesLock.Lock()
|
|
defer m.linesLock.Unlock()
|
|
|
|
for pin := range m.lines {
|
|
m.closeLineHelper(pin)
|
|
}
|
|
|
|
return m.chip.Close()
|
|
}
|