From 9bc838523f0e922a4572174ce32fff3d59401c7a Mon Sep 17 00:00:00 2001
From: Yorick Smilda <yorick@smilda.tech>
Date: Wed, 26 Jun 2024 21:03:39 +0200
Subject: [PATCH] Basic implementation of various backlight drivers

---
 backlight/PWM.go       | 31 +++++++++++++++++++++++++++++++
 backlight/backlight.go |  5 +++++
 backlight/onoff.go     | 20 ++++++++++++++++++++
 backlight/pinetime.go  | 33 +++++++++++++++++++++++++++++++++
 4 files changed, 89 insertions(+)
 create mode 100644 backlight/PWM.go
 create mode 100644 backlight/backlight.go
 create mode 100644 backlight/onoff.go
 create mode 100644 backlight/pinetime.go

diff --git a/backlight/PWM.go b/backlight/PWM.go
new file mode 100644
index 000000000..9fa9b1a65
--- /dev/null
+++ b/backlight/PWM.go
@@ -0,0 +1,31 @@
+package backlight
+
+import "machine"
+
+type PWM interface {
+	Configure(config machine.PWMConfig) error
+	Channel(pin machine.Pin) (channel uint8, err error)
+	Top() uint32
+	Set(channel uint8, value uint32)
+}
+
+type PWMDriver struct {
+	pwm PWM
+	ch  uint8
+}
+
+func NewPWMDriver(pwm PWM, pin machine.Pin) (PWMDriver, error) {
+	err := pwm.Configure(machine.PWMConfig{})
+	if err != nil {
+		return PWMDriver{}, err
+	}
+	ch, err := pwm.Channel(pin)
+	if err != nil {
+		return PWMDriver{}, err
+	}
+	return PWMDriver{pwm, ch}, nil
+}
+
+func (b PWMDriver) SetBrightness(brightness uint8) {
+	b.pwm.Set(b.ch, b.pwm.Top()*uint32(brightness)/255)
+}
diff --git a/backlight/backlight.go b/backlight/backlight.go
new file mode 100644
index 000000000..a89e32c97
--- /dev/null
+++ b/backlight/backlight.go
@@ -0,0 +1,5 @@
+package backlight
+
+type Driver interface {
+	SetBrightness(uint8)
+}
diff --git a/backlight/onoff.go b/backlight/onoff.go
new file mode 100644
index 000000000..ac28f9873
--- /dev/null
+++ b/backlight/onoff.go
@@ -0,0 +1,20 @@
+package backlight
+
+import "machine"
+
+type OnOffDriver struct {
+	blPin machine.Pin
+}
+
+func NewOnOffDriver(pin machine.Pin) OnOffDriver {
+	pin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	return OnOffDriver{blPin: pin}
+}
+
+func (b OnOffDriver) SetBrightness(brightness uint8) {
+	if brightness < 128 {
+		b.blPin.Low()
+	} else {
+		b.blPin.High()
+	}
+}
diff --git a/backlight/pinetime.go b/backlight/pinetime.go
new file mode 100644
index 000000000..c893900de
--- /dev/null
+++ b/backlight/pinetime.go
@@ -0,0 +1,33 @@
+package backlight
+
+import "machine"
+
+type PineTimeDriver struct {
+	blLowPin  machine.Pin
+	blMidPin  machine.Pin
+	blHighPin machine.Pin
+}
+
+func NewPineTimeDriver(lowPin, midPin, highPin machine.Pin) PineTimeDriver {
+	lowPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	midPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	highPin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+	return PineTimeDriver{blLowPin: lowPin, blMidPin: midPin, blHighPin: highPin}
+}
+
+// Not sure if you can combine the three pins to get intermediate brightness levels.s
+func (b PineTimeDriver) SetBrightness(brightness uint8) {
+	if brightness < 85 {
+		b.blLowPin.Low()
+		b.blMidPin.High()
+		b.blHighPin.High()
+	} else if brightness < 170 {
+		b.blLowPin.High()
+		b.blMidPin.Low()
+		b.blHighPin.High()
+	} else {
+		b.blLowPin.High()
+		b.blMidPin.High()
+		b.blHighPin.Low()
+	}
+}