machine: add DMA support to spi tx

src/examples/pyportal_boing/ili9341/README.md

@@ -0,0 +1,19 @@
+TinyGo driver for TFT displays using ILI9341 driver chips.
+
+These displays support 8-bit parallel, 16-bit parallel, or SPI interfaces.
+
+Examples of such displays include:
+
+ * [Adafruit PyPortal
+ ](https://www.adafruit.com/product/4116)
+ * [Adafruit 2.8" Touch Shield V2 (SPI)](http://www.adafruit.com/products/1651)
+ * [Adafruit 2.4" TFT LCD with Touchscreen Breakout w/MicroSD Socket](https://www.adafruit.com/product/2478)
+ * [2.8" TFT LCD with Touchscreen Breakout Board w/MicroSD Socket](https://www.adafruit.com/product/1770)
+ * [2.2" 18-bit color TFT LCD display with microSD card breakout](https://www.adafruit.com/product/1770)
+ * [TFT FeatherWing - 2.4" 320x240 Touchscreen For All Feathers](https://www.adafruit.com/product/3315)
+
+Currently this driver only supports an 8-bit parallel interface using ATSAMD51
+(this is the default configuration on PyPortal).  It should be relatively
+straightforward to implement a more generic SPI-based interface as well.
+Please see `parallel_atsamd51.go` for an example of what needs to be
+implemented if you are interested in contributing.

src/examples/pyportal_boing/ili9341/ili9341.go

@@ -0,0 +1,310 @@
+package ili9341
+
+import (
+	"errors"
+	"image/color"
+	"machine"
+	"time"
+)
+
+type Config struct {
+	Width    int16
+	Height   int16
+	Rotation Rotation
+}
+
+type Device struct {
+	width    int16
+	height   int16
+	rotation Rotation
+	driver   driver
+
+	dc  machine.Pin
+	cs  machine.Pin
+	rst machine.Pin
+	rd  machine.Pin
+}
+
+func (d *Device) Configure(config Config) {
+
+	if config.Width == 0 {
+		config.Width = TFTWIDTH
+	}
+	if config.Height == 0 {
+		config.Height = TFTHEIGHT
+	}
+	d.width = config.Width
+	d.height = config.Height
+	d.rotation = config.Rotation
+
+	output := machine.PinConfig{machine.PinOutput}
+
+	// configure chip select if there is one
+	if d.cs != machine.NoPin {
+		d.cs.Configure(output)
+		d.cs.High() // deselect
+	}
+
+	d.dc.Configure(output)
+	d.dc.High() // data mode
+
+	// driver-specific configuration
+	d.driver.configure(&config)
+
+	if d.rd != machine.NoPin {
+		d.rd.Configure(output)
+		d.rd.High()
+	}
+
+	// reset the display
+	if d.rst != machine.NoPin {
+		// configure hardware reset if there is one
+		d.rst.Configure(output)
+		d.rst.High()
+		delay(100)
+		d.rst.Low()
+		delay(100)
+		d.rst.High()
+		delay(200)
+	} else {
+		// if no hardware reset, send software reset
+		d.sendCommand(SWRESET, nil)
+		delay(150)
+	}
+
+	initCmd := []byte{
+		0xEF, 3, 0x03, 0x80, 0x02,
+		0xCF, 3, 0x00, 0xC1, 0x30,
+		0xED, 4, 0x64, 0x03, 0x12, 0x81,
+		0xE8, 3, 0x85, 0x00, 0x78,
+		0xCB, 5, 0x39, 0x2C, 0x00, 0x34, 0x02,
+		0xF7, 1, 0x20,
+		0xEA, 2, 0x00, 0x00,
+		PWCTR1, 1, 0x23, // Power control VRH[5:0]
+		PWCTR2, 1, 0x10, // Power control SAP[2:0];BT[3:0]
+		VMCTR1, 2, 0x3e, 0x28, // VCM control
+		VMCTR2, 1, 0x86, // VCM control2
+		MADCTL, 1, 0x48, // Memory Access Control
+		VSCRSADD, 1, 0x00, // Vertical scroll zero
+		PIXFMT, 1, 0x55,
+		FRMCTR1, 2, 0x00, 0x18,
+		DFUNCTR, 3, 0x08, 0x82, 0x27, // Display Function Control
+		0xF2, 1, 0x00, // 3Gamma Function Disable
+		GAMMASET, 1, 0x01, // Gamma curve selected
+		GMCTRP1, 15, 0x0F, 0x31, 0x2B, 0x0C, 0x0E, 0x08, // Set Gamma
+		0x4E, 0xF1, 0x37, 0x07, 0x10, 0x03, 0x0E, 0x09, 0x00,
+		GMCTRN1, 15, 0x00, 0x0E, 0x14, 0x03, 0x11, 0x07, // Set Gamma
+		0x31, 0xC1, 0x48, 0x08, 0x0F, 0x0C, 0x31, 0x36, 0x0F,
+		SLPOUT, 0x80, // Exit Sleep
+		DISPON, 0x80, // Display on
+		0x00, // End of list
+	}
+	for i, c := 0, len(initCmd); i < c; {
+		cmd := initCmd[i]
+		if cmd == 0x00 {
+			break
+		}
+		x := initCmd[i+1]
+		numArgs := int(x & 0x7F)
+		d.sendCommand(cmd, initCmd[i+2:i+2+numArgs])
+		if x&0x80 > 0 {
+			delay(150)
+		}
+		i += numArgs + 2
+	}
+
+	d.SetRotation(d.rotation)
+}
+
+// Size returns the current size of the display.
+func (d *Device) Size() (x, y int16) {
+	if d.rotation == 1 || d.rotation == 3 {
+		return d.height, d.width
+	}
+	return d.width, d.height
+}
+
+// SetPixel modifies the internal buffer.
+func (d *Device) SetPixel(x, y int16, c color.RGBA) {
+	d.setWindow(x, y, 1, 1)
+	c565 := RGBATo565(c)
+	d.startWrite()
+	d.driver.write16(c565)
+	d.endWrite()
+}
+
+// Display sends the buffer (if any) to the screen.
+func (d *Device) Display() error {
+	return nil
+}
+
+func (d *Device) DrawRGBBitmap(x, y int16, data []uint16, w, h int16) error {
+	k, i := d.Size()
+	if x < 0 || y < 0 || w <= 0 || h <= 0 ||
+		x >= k || (x+w) > k || y >= i || (y+h) > i {
+		return errors.New("rectangle coordinates outside display area")
+	}
+	d.setWindow(x, y, w, h)
+	d.startWrite()
+	d.driver.write16sl(data)
+	d.endWrite()
+	return nil
+}
+
+// FillRectangle fills a rectangle at a given coordinates with a color
+func (d *Device) FillRectangle(x, y, width, height int16, c color.RGBA) error {
+	k, i := d.Size()
+	if x < 0 || y < 0 || width <= 0 || height <= 0 ||
+		x >= k || (x+width) > k || y >= i || (y+height) > i {
+		return errors.New("rectangle coordinates outside display area")
+	}
+	d.setWindow(x, y, width, height)
+	c565 := RGBATo565(c)
+	d.startWrite()
+	d.driver.write16n(c565, int(width)*int(height))
+	d.endWrite()
+	return nil
+}
+
+// DrawRectangle fills a rectangle at a given coordinates with a color
+func (d *Device) DrawRectangle(x, y, w, h int16, c color.RGBA) error {
+	if err := d.DrawFastHLine(x, x+w-1, y, c); err != nil {
+		return err
+	}
+	if err := d.DrawFastHLine(x, x+w-1, y+h-1, c); err != nil {
+		return err
+	}
+	if err := d.DrawFastVLine(x, y, y+h-1, c); err != nil {
+		return err
+	}
+	if err := d.DrawFastVLine(x+w-1, y, y+h-1, c); err != nil {
+		return err
+	}
+	return nil
+}
+
+// DrawFastVLine draws a vertical line faster than using SetPixel
+func (d *Device) DrawFastVLine(x, y0, y1 int16, c color.RGBA) error {
+	if y0 > y1 {
+		y0, y1 = y1, y0
+	}
+	return d.FillRectangle(x, y0, 1, y1-y0+1, c)
+}
+
+// DrawFastHLine draws a horizontal line faster than using SetPixel
+func (d *Device) DrawFastHLine(x0, x1, y int16, c color.RGBA) error {
+	if x0 > x1 {
+		x0, x1 = x1, x0
+	}
+	return d.FillRectangle(x0, y, x1-x0+1, 1, c)
+}
+
+// FillScreen fills the screen with a given color
+func (d *Device) FillScreen(c color.RGBA) {
+	if d.rotation == Rotation0 || d.rotation == Rotation180 {
+		d.FillRectangle(0, 0, d.width, d.height, c)
+	} else {
+		d.FillRectangle(0, 0, d.height, d.width, c)
+	}
+}
+
+func (d *Device) GetRotation() Rotation {
+	return d.rotation
+}
+
+// SetRotation changes the rotation of the device (clock-wise)
+func (d *Device) SetRotation(rotation Rotation) {
+	madctl := uint8(0)
+	switch rotation % 4 {
+	case 0:
+		madctl = MADCTL_MX | MADCTL_BGR
+	case 1:
+		madctl = MADCTL_MV | MADCTL_BGR
+	case 2:
+		madctl = MADCTL_MY | MADCTL_BGR
+	case 3:
+		madctl = MADCTL_MX | MADCTL_MY | MADCTL_MV | MADCTL_BGR
+	}
+	d.sendCommand(MADCTL, []uint8{madctl})
+	d.rotation = rotation
+}
+
+// SetScrollWindow sets an area to scroll with fixed top and bottom parts of the display
+func (d *Device) SetScrollArea(topFixedArea, bottomFixedArea int16) {
+	d.sendCommand(VSCRDEF, []uint8{
+		uint8(topFixedArea >> 8), uint8(topFixedArea),
+		uint8(d.height - topFixedArea - bottomFixedArea>>8),
+		uint8(d.height - topFixedArea - bottomFixedArea),
+		uint8(bottomFixedArea >> 8), uint8(bottomFixedArea),
+	})
+}
+
+// SetScroll sets the vertical scroll address of the display.
+func (d *Device) SetScroll(line int16) {
+	d.sendCommand(VSCRSADD, []uint8{uint8(line >> 8), uint8(line)})
+}
+
+// SpotScroll returns the display to its normal state
+func (d *Device) StopScroll() {
+	d.sendCommand(NORON, nil)
+}
+
+// setWindow prepares the screen to be modified at a given rectangle
+func (d *Device) setWindow(x, y, w, h int16) {
+	//x += d.columnOffset
+	//y += d.rowOffset
+	d.sendCommand(CASET, []uint8{
+		uint8(x >> 8), uint8(x), uint8((x + w - 1) >> 8), uint8(x + w - 1),
+	})
+	d.sendCommand(PASET, []uint8{
+		uint8(y >> 8), uint8(y), uint8((y + h - 1) >> 8), uint8(y + h - 1),
+	})
+	d.sendCommand(RAMWR, nil)
+}
+
+//go:inline
+func (d *Device) startWrite() {
+	if d.cs != machine.NoPin {
+		d.cs.Low()
+	}
+}
+
+//go:inline
+func (d *Device) endWrite() {
+	if d.cs != machine.NoPin {
+		d.cs.High()
+	}
+}
+
+func (d *Device) sendCommand(cmd byte, data []byte) {
+	d.startWrite()
+	d.dc.Low()
+	d.driver.write8(cmd)
+	d.dc.High()
+	d.driver.write8sl(data)
+	d.endWrite()
+}
+
+type driver interface {
+	configure(config *Config)
+	write8(b byte)
+	write8n(b byte, n int)
+	write8sl(b []byte)
+	write16(data uint16)
+	write16n(data uint16, n int)
+	write16sl(data []uint16)
+}
+
+func delay(m int) {
+	t := time.Now().UnixNano() + int64(time.Duration(m*1000)*time.Microsecond)
+	for time.Now().UnixNano() < t {
+	}
+}
+
+// RGBATo565 converts a color.RGBA to uint16 used in the display
+func RGBATo565(c color.RGBA) uint16 {
+	r, g, b, _ := c.RGBA()
+	return uint16((r & 0xF800) +
+		((g & 0xFC00) >> 5) +
+		((b & 0xF800) >> 11))
+}