1 files changed, 258 insertions, 0 deletions
diff --git a/src/machine/machine_rp2_gpio.go b/src/machine/machine_rp2_gpio.go
new file mode 100644
index 000000000..d49d12f2b
--- /dev/null
+++ b/src/machine/machine_rp2_gpio.go
@@ -0,0 +1,258 @@
+//go:build rp2040 || rp2350
+
+package machine
+
+import (
+	"device/rp"
+	"runtime/interrupt"
+	"runtime/volatile"
+	"unsafe"
+)
+
+type ioType struct {
+	status volatile.Register32
+	ctrl   volatile.Register32
+}
+
+type irqCtrl struct {
+	intE [_NUMBANK0_IRQS]volatile.Register32
+	intF [_NUMBANK0_IRQS]volatile.Register32
+	intS [_NUMBANK0_IRQS]volatile.Register32
+}
+
+type irqSummary struct {
+	proc [2]struct {
+		secure    [2]volatile.Register32
+		nonsecure [2]volatile.Register32
+	}
+	comaWake struct {
+		secure    [2]volatile.Register32
+		nonsecure [2]volatile.Register32
+	}
+}
+
+type ioBank0Type struct {
+	io                 [_NUMBANK0_GPIOS]ioType
+	irqsum             [rp2350ExtraReg]irqSummary
+	intR               [_NUMBANK0_IRQS]volatile.Register32
+	proc0IRQctrl       irqCtrl
+	proc1IRQctrl       irqCtrl
+	dormantWakeIRQctrl irqCtrl
+}
+
+var ioBank0 = (*ioBank0Type)(unsafe.Pointer(rp.IO_BANK0))
+
+type padsBank0Type struct {
+	voltageSelect volatile.Register32
+	io            [_NUMBANK0_GPIOS]volatile.Register32
+}
+
+var padsBank0 = (*padsBank0Type)(unsafe.Pointer(rp.PADS_BANK0))
+
+// pinFunc represents a GPIO function.
+//
+// Each GPIO can have one function selected at a time.
+// Likewise, each peripheral input (e.g. UART0 RX) should only be  selected
+// on one GPIO at a time. If the same peripheral input is connected to multiple GPIOs,
+// the peripheral sees the logical OR of these GPIO inputs.
+type pinFunc uint8
+
+func (p Pin) PortMaskSet() (*uint32, uint32) {
+	return (*uint32)(unsafe.Pointer(&rp.SIO.GPIO_OUT_SET)), 1 << p
+}
+
+// set drives the pin high
+func (p Pin) set() {
+	mask := uint32(1) << p
+	rp.SIO.GPIO_OUT_SET.Set(mask)
+}
+
+func (p Pin) PortMaskClear() (*uint32, uint32) {
+	return (*uint32)(unsafe.Pointer(&rp.SIO.GPIO_OUT_CLR)), 1 << p
+}
+
+// clr drives the pin low
+func (p Pin) clr() {
+	mask := uint32(1) << p
+	rp.SIO.GPIO_OUT_CLR.Set(mask)
+}
+
+// xor toggles the pin
+func (p Pin) xor() {
+	mask := uint32(1) << p
+	rp.SIO.GPIO_OUT_XOR.Set(mask)
+}
+
+// get returns the pin value
+func (p Pin) get() bool {
+	return rp.SIO.GPIO_IN.HasBits(1 << p)
+}
+
+func (p Pin) ioCtrl() *volatile.Register32 {
+	return &ioBank0.io[p].ctrl
+}
+
+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)
+}
+
+func (p Pin) pulloff() {
+	p.padCtrl().ClearBits(rp.PADS_BANK0_GPIO0_PDE)
+	p.padCtrl().ClearBits(rp.PADS_BANK0_GPIO0_PUE)
+}
+
+// setSlew sets pad slew rate control.
+// true sets to fast. false sets to slow.
+func (p Pin) setSlew(sr bool) {
+	p.padCtrl().ReplaceBits(boolToBit(sr)<<rp.PADS_BANK0_GPIO0_SLEWFAST_Pos, rp.PADS_BANK0_GPIO0_SLEWFAST_Msk, 0)
+}
+
+// setSchmitt enables or disables Schmitt trigger.
+func (p Pin) setSchmitt(trigger bool) {
+	p.padCtrl().ReplaceBits(boolToBit(trigger)<<rp.PADS_BANK0_GPIO0_SCHMITT_Pos, rp.PADS_BANK0_GPIO0_SCHMITT_Msk, 0)
+}
+
+// setFunc will set pin function to fn.
+func (p Pin) setFunc(fn pinFunc) {
+	// Set input enable, Clear output disable
+	p.padCtrl().ReplaceBits(rp.PADS_BANK0_GPIO0_IE, padEnableMask, 0)
+
+	// Zero all fields apart from fsel; we want this IO to do what the peripheral tells it.
+	// This doesn't affect e.g. pullup/pulldown, as these are in pad controls.
+	p.ioCtrl().Set(uint32(fn) << rp.IO_BANK0_GPIO0_CTRL_FUNCSEL_Pos)
+}
+
+// init initializes the gpio pin
+func (p Pin) init() {
+	mask := uint32(1) << p
+	rp.SIO.GPIO_OE_CLR.Set(mask)
+	p.clr()
+}
+
+// Set drives the pin high if value is true else drives it low.
+func (p Pin) Set(value bool) {
+	if p == NoPin {
+		return
+	}
+	if value {
+		p.set()
+	} else {
+		p.clr()
+	}
+}
+
+// Get reads the pin value.
+func (p Pin) Get() bool {
+	return p.get()
+}
+
+// PinChange represents one or more trigger events that can happen on a given GPIO pin
+// on the RP2040. ORed PinChanges are valid input to most IRQ functions.
+type PinChange uint8
+
+// Pin change interrupt constants for SetInterrupt.
+const (
+	// Edge falling
+	PinFalling PinChange = 4 << iota
+	// Edge rising
+	PinRising
+
+	PinToggle = PinFalling | PinRising
+)
+
+// Callbacks to be called for pins configured with SetInterrupt.
+var (
+	pinCallbacks [2][_NUMBANK0_GPIOS]func(Pin)
+	setInt       [2][_NUMBANK0_GPIOS]bool
+)
+
+// SetInterrupt sets an interrupt to be executed when a particular pin changes
+// state. The pin should already be configured as an input, including a pull up
+// or down if no external pull is provided.
+//
+// This call will replace a previously set callback on this pin. You can pass a
+// nil func to unset the pin change interrupt. If you do so, the change
+// parameter is ignored and can be set to any value (such as 0).
+func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) error {
+	if p == NoPin {
+		return nil
+	}
+	if p > 31 || p < 0 {
+		return ErrInvalidInputPin
+	}
+	core := CurrentCore()
+	if callback == nil {
+		// disable current interrupt
+		p.setInterrupt(change, false)
+		pinCallbacks[core][p] = nil
+		return nil
+	}
+
+	if pinCallbacks[core][p] != nil {
+		// Callback already configured. Should disable callback by passing a nil callback first.
+		return ErrNoPinChangeChannel
+	}
+	p.setInterrupt(change, true)
+	pinCallbacks[core][p] = callback
+
+	if setInt[core][p] {
+		// interrupt has already been set. Exit.
+		return nil
+	}
+	interrupt.New(rp.IRQ_IO_IRQ_BANK0, gpioHandleInterrupt).Enable()
+	irqSet(rp.IRQ_IO_IRQ_BANK0, true)
+	return nil
+}
+
+// gpioHandleInterrupt finds the corresponding pin for the interrupt.
+// C SDK equivalent of gpio_irq_handler
+func gpioHandleInterrupt(intr interrupt.Interrupt) {
+
+	core := CurrentCore()
+	var gpio Pin
+	for gpio = 0; gpio < _NUMBANK0_GPIOS; gpio++ {
+		var base *irqCtrl
+		switch core {
+		case 0:
+			base = &ioBank0.proc0IRQctrl
+		case 1:
+			base = &ioBank0.proc1IRQctrl
+		}
+
+		statreg := base.intS[gpio>>3].Get()
+		change := getIntChange(gpio, statreg)
+		if change != 0 {
+			gpio.acknowledgeInterrupt(change)
+			callback := pinCallbacks[core][gpio]
+			if callback != nil {
+				callback(gpio)
+			}
+		}
+	}
+}
+
+// events returns the bit representation of the pin change for the rp2040.
+func (change PinChange) events() uint32 {
+	return uint32(change)
+}
+
+// intBit is the bit storage form of a PinChange for a given Pin
+// in the IO_BANK0 interrupt registers (page 269 RP2040 Datasheet).
+func (p Pin) ioIntBit(change PinChange) uint32 {
+	return change.events() << (4 * (p % 8))
+}
+
+// Acquire interrupt data from a INT status register.
+func getIntChange(p Pin, status uint32) PinChange {
+	return PinChange(status>>(4*(p%8))) & 0xf
+}