nucleol552ze: implementation with CLOCK, LED, and UART

src/machine/machine_stm32l5x2.go

@@ -0,0 +1,42 @@
+// +build stm32l5x2
+
+package machine
+
+// Peripheral abstraction layer for the stm32f407
+
+import (
+	"device/stm32"
+	"runtime/interrupt"
+)
+
+func CPUFrequency() uint32 {
+	return 110000000
+}
+
+//---------- UART related types and code
+
+// UART representation
+type UART struct {
+	Buffer          *RingBuffer
+	Bus             *stm32.USART_Type
+	Interrupt       interrupt.Interrupt
+	AltFuncSelector stm32.AltFunc
+}
+
+// Configure the UART.
+func (uart UART) configurePins(config UARTConfig) {
+	if config.RX.getPort() == stm32.GPIOG || config.TX.getPort() == stm32.GPIOG {
+		// Enable VDDIO2 power supply, which is an independant power supply for the PGx pins
+		stm32.PWR.CR2.SetBits(stm32.PWR_CR2_IOSV)
+	}
+
+	// enable the alternate functions on the TX and RX pins
+	config.TX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTTX}, uart.AltFuncSelector)
+	config.RX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTRX}, uart.AltFuncSelector)
+}
+
+// UART baudrate calc based on the bus and clockspeed
+// NOTE: keep this in sync with the runtime/runtime_stm32l5x2.go clock init code
+func (uart UART) getBaudRateDivisor(baudRate uint32) uint32 {
+	return 256 * (CPUFrequency() / baudRate)
+}