Replace Safe functions with legacy.PinOutput

Author: ysoldak

bmi160/bmi160.go

@@ -4,6 +4,7 @@ import (
 	"time"
 
 	"tinygo.org/x/drivers"
+	"tinygo.org/x/drivers/internal/legacy"
 )
 
 // DeviceSPI is the SPI interface to a BMI160 accelerometer/gyroscope. There is
@@ -23,7 +24,7 @@ type DeviceSPI struct {
 // using this device.
 func NewSPI(csb drivers.PinOutput, spi drivers.SPI) *DeviceSPI {
 	return &DeviceSPI{
-		CSB: drivers.SafePinOutput(csb), // chip select
+		CSB: legacy.PinOutput(csb), // chip select
 		Bus: spi,
 	}
 }

buzzer/buzzer.go

@@ -17,7 +17,7 @@ type Device struct {
 // New returns a new buzzer driver given which pin to use
 func New(pin drivers.PinOutput) Device {
 	return Device{
-		set:  drivers.SafePinOutput(pin).Set,
+		set:  pin.Set,
 		High: false,
 		BPM:  96.0,
 	}

dht/thermometer.go

@@ -45,9 +45,7 @@ type device struct {
 func (t *device) ReadMeasurements() error {
 	// initial waiting
 	state := powerUp(t.pin)
-	defer func() {
-		t.pin.Set(state)
-	}()
+	defer t.pin.Set(state)
 	err := t.read()
 	if err == nil {
 		t.initialized = true
@@ -213,7 +211,7 @@ func waitForDataTransmission(p drivers.PinInput) error {
 func NewDummyDevice(pin drivers.Pin, deviceType DeviceType) DummyDevice {
 	pin.Set(true)
 	return &device{
-		pin:          drivers.SafePin(pin),
+		pin:          pin,
 		measurements: deviceType,
 		initialized:  false,
 		temperature:  0,

dht/timesafethermometer.go

@@ -129,7 +129,7 @@ func New(pin drivers.Pin, deviceType DeviceType) Device {
 	pin.Set(true)
 	return &managedDevice{
 		t: device{
-			pin:          drivers.SafePin(pin),
+			pin:          pin,
 			measurements: deviceType,
 			initialized:  false,
 		},
@@ -146,7 +146,7 @@ func NewWithPolicy(pin drivers.Pin, deviceType DeviceType, updatePolicy UpdatePo
 	pin.Set(true)
 	result := &managedDevice{
 		t: device{
-			pin:          drivers.SafePin(pin),
+			pin:          pin,
 			measurements: deviceType,
 			initialized:  false,
 		},

examples/dht/main.go

@@ -1,14 +1,18 @@
+//go:build baremetal && tinygo
+
 package main
 
 import (
 	"fmt"
 	"machine"
 	"time"
+
 	"tinygo.org/x/drivers/dht"
+	"tinygo.org/x/drivers/tinygo"
 )
 
 func main() {
-	pin := machine.D6
+	pin := tinygo.New(machine.D6)
 	dhtSensor := dht.New(pin, dht.DHT11)
 	for {
 		temp, hum, err := dhtSensor.Measurements()

examples/hcsr04/main.go

@@ -5,10 +5,13 @@ import (
 	"time"
 
 	"tinygo.org/x/drivers/hcsr04"
+	"tinygo.org/x/drivers/tinygo"
 )
 
 func main() {
-	sensor := hcsr04.New(machine.D10, machine.D9)
+	trigger := tinygo.New(machine.D10) // automatically configures pin as output
+	echo := tinygo.New(machine.D9)     // automatically configures pin as input
+	sensor := hcsr04.New(trigger, echo)
 	sensor.Configure()
 
 	println("Ultrasonic starts")

hcsr04/hcsr04.go

@@ -5,20 +5,22 @@
 package hcsr04
 
 import (
-	"machine"
 	"time"
+
+	"tinygo.org/x/drivers"
 )
 
 const TIMEOUT = 23324 // max sensing distance (4m)
 
 // Device holds the pins
 type Device struct {
-	trigger machine.Pin
-	echo    machine.Pin
+	trigger drivers.PinOutput
+	echo    drivers.PinInput
 }
 
-// New returns a new ultrasonic driver given 2 pins
-func New(trigger, echo machine.Pin) Device {
+// New returns a new ultrasonic driver given 2 pins.
+// Pins must be configured as output (trigger) and input (echo).
+func New(trigger drivers.PinOutput, echo drivers.PinInput) Device {
 	return Device{
 		trigger: trigger,
 		echo:    echo,
@@ -27,8 +29,7 @@ func New(trigger, echo machine.Pin) Device {
 
 // Configure configures the pins of the Device
 func (d *Device) Configure() {
-	d.trigger.Configure(machine.PinConfig{Mode: machine.PinOutput})
-	d.echo.Configure(machine.PinConfig{Mode: machine.PinInput})
+	// no-op, left for API compatibility
 }
 
 // ReadDistance returns the distance of the object in mm
@@ -45,11 +46,11 @@ func (d *Device) ReadDistance() int32 {
 // ReadPulse returns the time of the pulse (roundtrip) in microseconds
 func (d *Device) ReadPulse() int32 {
 	t := time.Now()
-	d.trigger.Low()
+	d.trigger.Set(false)
 	time.Sleep(2 * time.Microsecond)
-	d.trigger.High()
+	d.trigger.Set(true)
 	time.Sleep(10 * time.Microsecond)
-	d.trigger.Low()
+	d.trigger.Set(false)
 	i := uint8(0)
 	for {
 		if d.echo.Get() {

internal/legacy/pinlegacy_generic.go

@@ -0,0 +1,9 @@
+//go:build !(baremetal && tinygo)
+
+package legacy
+
+import "tinygo.org/x/drivers"
+
+func PinOutput(pin drivers.PinOutput) drivers.PinOutput {
+	return pin
+}

internal/legacy/pinlegacy_tinygo.go

@@ -0,0 +1,16 @@
+//go:build baremetal && tinygo
+
+package legacy
+
+import (
+	"machine"
+
+	"tinygo.org/x/drivers"
+)
+
+func PinOutput(pin drivers.PinOutput) drivers.PinOutput {
+	if p, ok := pin.(machine.Pin); ok {
+		p.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	}
+	return pin
+}

pin.go

@@ -4,13 +4,17 @@ package drivers
 // allowing the use of different hardware or libraries without changing driver code.
 //
 // Note, pin mode functionality is not part of the Pin interface.
-// Implementations must ensure correct pin mode is set when Get or Set methods are called.
+// Client code is responsible for configuring pin modes correctly.
+// This can be done either before passing the pin to a driver constructor
+// or by ensuring correct pin mode is set when Get or Set methods are called.
+// See rpio package for an example of a pin implementation that does this.
 //
-// Drivers must use SafePin(), SafePinInput() and SafePinOutput() wrappers in constructors.
-// The client code can pass either machine.Pin or a custom implementation of the Pin interface.
-// Wrappers for TinyGo's machine.Pin are provided in pin_tinygo.go.
-// It's custom implementation's responsibility to configure the pin modes correctly as
-// Wrappers in pin_generic.go are no-ops.
+// Drivers that used to configure output pin mode in their constructors can use
+// legacy.PinOutput() wrapper to keep the same behavior for machine.Pin.
+// See internal/legacy/pinlegacy_tinygo.go and internal/legacy/pinlegacy_generic.go for details.
+//
+// All new drivers are encouraged to not configure pin modes in their constructors and
+// do not depend on either machine package or legacy wrappers.
 
 // PinInput is an interface for reading the state of a pin.
 type PinInput interface {