sx126x: refactor to RadioController interface to more easily handle non-STM32WL boards and remove duplicated code

Signed-off-by: deadprogram <ron@hybridgroup.com>

sx126x/radiocontrol_stm32wl.go

@@ -0,0 +1,85 @@
+//go:build stm32wlx
+
+package sx126x
+
+import (
+	"device/stm32"
+
+	"runtime/interrupt"
+)
+
+// STM32RadioControl helps implement the RadioController interface
+type STM32RadioControl struct {
+	irqHandler func()
+}
+
+// SetNss sets the NSS line aka chip select for SPI.
+func (rc *STM32RadioControl) SetNss(state bool) error {
+	if state {
+		stm32.PWR.SUBGHZSPICR.SetBits(stm32.PWR_SUBGHZSPICR_NSS)
+	} else {
+		stm32.PWR.SUBGHZSPICR.ClearBits(stm32.PWR_SUBGHZSPICR_NSS)
+	}
+
+	return nil
+}
+
+// WaitWhileBusy wait until the radio is no longer busy
+func (rc *STM32RadioControl) WaitWhileBusy() error {
+	count := 100
+	var rfbusyms, rfbusys bool
+	for count > 0 {
+		rfbusyms = stm32.PWR.SR2.HasBits(stm32.PWR_SR2_RFBUSYMS)
+		rfbusys = stm32.PWR.SR2.HasBits(stm32.PWR_SR2_RFBUSYS)
+
+		if !(rfbusyms && rfbusys) {
+			return nil
+		}
+		count--
+	}
+	return errWaitWhileBusyTimeout
+}
+
+// init() configures whatever needed for sx126x radio control
+func init() {
+	// Enable APB3 Periph clock and delay
+	stm32.RCC.APB3ENR.SetBits(stm32.RCC_APB3ENR_SUBGHZSPIEN)
+	_ = stm32.RCC.APB3ENR.Get()
+
+	// Disable radio reset and wait it's ready
+	stm32.RCC.CSR.ClearBits(stm32.RCC_CSR_RFRST)
+	for stm32.RCC.CSR.HasBits(stm32.RCC_CSR_RFRSTF) {
+	}
+
+	// Set NSS line low
+	stm32.PWR.SUBGHZSPICR.SetBits(stm32.PWR_SUBGHZSPICR_NSS)
+
+	// Enable radio busy wakeup from Standby for CPU
+	stm32.PWR.CR3.SetBits(stm32.PWR_CR3_EWRFBUSY)
+
+	// Clear busy flag
+	stm32.PWR.SCR.Set(stm32.PWR_SCR_CWRFBUSYF)
+
+	// Enable SUBGHZ Spi
+	// - /8 Prescaler
+	// - Software Slave Management (NSS)
+	// - FIFO Threshold and 8bit size
+	stm32.SPI3.CR1.ClearBits(stm32.SPI_CR1_SPE)
+	stm32.SPI3.CR1.Set(stm32.SPI_CR1_MSTR | stm32.SPI_CR1_SSI | (0b010 << 3) | stm32.SPI_CR1_SSM)
+	stm32.SPI3.CR2.Set(stm32.SPI_CR2_FRXTH | (0b111 << 8))
+	stm32.SPI3.CR1.SetBits(stm32.SPI_CR1_SPE)
+}
+
+func (rc *STM32RadioControl) SetupInterrupts(handler func()) error {
+	irqHandler = handler
+	intr := interrupt.New(stm32.IRQ_Radio_IRQ_Busy, handleInterrupt)
+	intr.Enable()
+
+	return nil
+}
+
+var irqHandler func()
+
+func handleInterrupt(interrupt.Interrupt) {
+	irqHandler()
+}