ili9341: add standard SPI driver

ili9341/spi.go

@@ -0,0 +1,71 @@
+// +build !atsamd51,!atsamd21
+
+package ili9341
+
+import (
+	"machine"
+)
+
+var buf [64]byte
+
+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) {
+	buf[0] = b
+	pd.bus.Tx(buf[:1], nil)
+}
+
+func (pd *spiDriver) write8n(b byte, n int) {
+	buf[0] = b
+	for i := 0; i < n; i++ {
+		pd.bus.Tx(buf[:1], nil)
+	}
+}
+
+func (pd *spiDriver) write8sl(b []byte) {
+	pd.bus.Tx(b, nil)
+}
+
+func (pd *spiDriver) write16(data uint16) {
+	buf[0] = uint8(data >> 8)
+	buf[1] = uint8(data)
+	pd.bus.Tx(buf[:2], nil)
+}
+
+func (pd *spiDriver) write16n(data uint16, n int) {
+	for i := 0; i < len(buf); i += 2 {
+		buf[i] = uint8(data >> 8)
+		buf[i+1] = uint8(data)
+	}
+
+	for i := 0; i < (n >> 5); i++ {
+		pd.bus.Tx(buf[:], nil)
+	}
+
+	pd.bus.Tx(buf[:n%64], nil)
+}
+
+func (pd *spiDriver) write16sl(data []uint16) {
+	for i, c := 0, len(data); i < c; i++ {
+		buf[0] = uint8(data[i] >> 8)
+		buf[1] = uint8(data[i])
+		pd.bus.Tx(buf[:2], nil)
+	}
+}