From 36dffb55545b9e64ca53b408a9343a7a56bbbbc1 Mon Sep 17 00:00:00 2001
From: deadprogram <ron@hybridgroup.com>
Date: Sat, 29 May 2021 10:41:19 +0200
Subject: [PATCH] machine/rp2040: add support for GPIO input

---
 src/machine/machine_rp2040_gpio.go | 32 +++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/src/machine/machine_rp2040_gpio.go b/src/machine/machine_rp2040_gpio.go
index 1d35254c..b82e0435 100644
--- a/src/machine/machine_rp2040_gpio.go
+++ b/src/machine/machine_rp2040_gpio.go
@@ -63,6 +63,9 @@ const (
 
 const (
 	PinOutput PinMode = iota
+	PinInput
+	PinInputPulldown
+	PinInputPullup
 )
 
 // set drives the pin high
@@ -83,6 +86,11 @@ func (p Pin) xor() {
 	rp.SIO.GPIO_OUT_XOR.Set(mask)
 }
 
+// get returns the pin value
+func (p Pin) get() bool {
+	return rp.SIO.GPIO_IN.HasBits(uint32(1) << p)
+}
+
 func (p Pin) ioCtrl() *volatile.Register32 {
 	return &ioBank0.io[p].ctrl
 }
@@ -91,6 +99,16 @@ func (p Pin) padCtrl() *volatile.Register32 {
 	return &padsBank0.io[p]
 }
 
+func (p Pin) pullup() {
+	p.padCtrl().SetBits(rp.PADS_BANK0_GPIO0_PUE)
+	p.padCtrl().ClearBits(rp.PADS_BANK0_GPIO0_PDE)
+}
+
+func (p Pin) pulldown() {
+	p.padCtrl().SetBits(rp.PADS_BANK0_GPIO0_PDE)
+	p.padCtrl().ClearBits(rp.PADS_BANK0_GPIO0_PUE)
+}
+
 // setFunc will set pin function to fn.
 func (p Pin) setFunc(fn pinFunc) {
 	// Set input enable, Clear output disable
@@ -108,7 +126,6 @@ func (p Pin) init() {
 	rp.SIO.GPIO_OE_CLR.Set(mask)
 	p.clr()
 	p.setFunc(fnSIO)
-
 }
 
 // Configure configures the gpio pin as per mode.
@@ -118,6 +135,14 @@ func (p Pin) Configure(config PinConfig) {
 	switch config.Mode {
 	case PinOutput:
 		rp.SIO.GPIO_OE_SET.Set(mask)
+	case PinInput:
+		rp.SIO.GPIO_OE_CLR.Set(mask)
+	case PinInputPulldown:
+		rp.SIO.GPIO_OE_CLR.Set(mask)
+		p.pulldown()
+	case PinInputPullup:
+		rp.SIO.GPIO_OE_CLR.Set(mask)
+		p.pullup()
 	}
 }
 
@@ -129,3 +154,8 @@ func (p Pin) Set(value bool) {
 		p.clr()
 	}
 }
+
+// Get reads the pin value.
+func (p Pin) Get() bool {
+	return p.get()
+}