ILI9341: add SPI driver for STM32F4

examples/ili9341/pyportal_boing/feather-stm32f405.go

@@ -0,0 +1,34 @@
+// +build feather_stm32f405
+
+package main
+
+import (
+	"machine"
+
+	"tinygo.org/x/drivers/ili9341"
+)
+
+var (
+	csPin   = machine.D12
+	dcPin   = machine.D10
+	display = ili9341.NewSPI(
+		machine.SPI0,
+		dcPin,
+		csPin,
+		machine.D8, // if wired to 3.3V, pick an unused pin
+	)
+
+	// ILI9341's LED pin. set this to an unused pin (but not NoPin!) if
+	// wired via resistor straight to 3.3V. the boing example tries to
+	// set this pin and will panic if NoPin is used.
+	backlight = machine.D13
+)
+
+func init() {
+	machine.SPI0.Configure(machine.SPIConfig{
+		SCK:       machine.SPI0_SCK_PIN,
+		SDO:       machine.SPI0_SDO_PIN,
+		SDI:       machine.SPI0_SDI_PIN,
+		Frequency: 40000000,
+	})
+}

examples/ili9341/pyportal_boing/main.go

@@ -58,6 +58,7 @@ func main() {
 	backlight.High()
 
 	display.SetRotation(ili9341.Rotation270)
+	time.Sleep(50 * time.Millisecond)
 	DrawBackground()
 
 	startTime = time.Now().UnixNano()

ili9341/spi_stm32f4.go

@@ -0,0 +1,142 @@
+// +build stm32f4
+
+package ili9341
+
+import (
+	"device/stm32"
+	"machine"
+)
+
+type spiDriver struct {
+	bus machine.SPI
+}
+
+func NewSPI(bus machine.SPI, dc, cs, rst machine.Pin) *Device {
+	return &Device{
+		dc:  dc,
+		cs:  cs,
+		rst: rst,
+		rd:  machine.NoPin,
+		driver: &spiDriver{
+			bus: bus,
+		},
+	}
+}
+
+func (pd *spiDriver) configure(config *Config) {
+}
+
+func (pd *spiDriver) write8(b byte) {
+	if !pd.bus.Bus.CR1.HasBits(stm32.SPI_CR1_SPE) {
+		pd.bus.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
+	}
+
+	pd.setWord(b, true, true)
+
+	pd.bus.Bus.CR1.ClearBits(stm32.SPI_CR1_SPE)
+}
+
+func (pd *spiDriver) write8n(b byte, n int) {
+	if !pd.bus.Bus.CR1.HasBits(stm32.SPI_CR1_SPE) {
+		pd.bus.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
+	}
+
+	for i := 0; i < n; i++ {
+		pd.setWord(b, i == 0, i+1 == n)
+	}
+
+	pd.bus.Bus.CR1.ClearBits(stm32.SPI_CR1_SPE)
+}
+
+func (pd *spiDriver) write8sl(b []byte) {
+	if !pd.bus.Bus.CR1.HasBits(stm32.SPI_CR1_SPE) {
+		pd.bus.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
+	}
+
+	for i, w := range b {
+		pd.setWord(w, i == 0, i+1 == len(b))
+	}
+
+	pd.bus.Bus.CR1.ClearBits(stm32.SPI_CR1_SPE)
+}
+
+func (pd *spiDriver) write16(data uint16) {
+	if !pd.bus.Bus.CR1.HasBits(stm32.SPI_CR1_SPE) {
+		pd.bus.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
+	}
+
+	pd.setWord(uint8(data>>8), true, false)
+	pd.setWord(uint8(data), false, true)
+
+	pd.bus.Bus.CR1.ClearBits(stm32.SPI_CR1_SPE)
+}
+
+func (pd *spiDriver) write16n(data uint16, n int) {
+	if !pd.bus.Bus.CR1.HasBits(stm32.SPI_CR1_SPE) {
+		pd.bus.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
+	}
+
+	for i := 0; i < n; i++ {
+		pd.setWord(uint8(data>>8), i == 0, false)
+		pd.setWord(uint8(data), false, i+1 == n)
+	}
+
+	pd.bus.Bus.CR1.ClearBits(stm32.SPI_CR1_SPE)
+}
+
+func (pd *spiDriver) write16sl(data []uint16) {
+	if !pd.bus.Bus.CR1.HasBits(stm32.SPI_CR1_SPE) {
+		pd.bus.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
+	}
+
+	for i, w := range data {
+		pd.setWord(uint8(w>>8), i == 0, false)
+		pd.setWord(uint8(w), false, i+1 == len(data))
+	}
+
+	pd.bus.Bus.CR1.ClearBits(stm32.SPI_CR1_SPE)
+}
+
+// puts a single 8-bit word in the SPI data register (DR).
+// if first (first word being transmitted) is false, waits for the SPI transmit
+// buffer empty bit (TXE) is set before putting the word in DR.
+// if last (last word being transmitted) is true, waits for the SPI transmit
+// buffer empty bit (TXE) is set and SPI bus busy bit (BSY) is clear before
+// returning.
+// for all wait operations, a fixed number of wait iterations (const tryMax) are
+// performed before a timeout is assumed.
+// if timeout occurs, returns false. otherwise, returns true.
+func (pd *spiDriver) setWord(word uint8, first bool, last bool) bool {
+
+	const tryMax = 10000
+
+	canWrite := first
+	for i := 0; (!canWrite) && (i < tryMax); i++ {
+		canWrite = pd.bus.Bus.SR.HasBits(stm32.SPI_SR_TXE)
+	}
+	if !canWrite {
+		return false // timeout
+	}
+
+	pd.bus.Bus.DR.Set(uint32(word))
+
+	if last {
+		canReturn := false
+		for i := 0; (!canReturn) && (i < tryMax); i++ {
+			canReturn = pd.bus.Bus.SR.HasBits(stm32.SPI_SR_TXE)
+		}
+		if !canReturn {
+			return false // timeout
+		}
+
+		canReturn = false
+		for i := 0; (!canReturn) && (i < tryMax); i++ {
+			canReturn = !pd.bus.Bus.SR.HasBits(stm32.SPI_SR_BSY)
+		}
+		if !canReturn {
+			return false // timeout
+		}
+	}
+
+	return true
+}