maixbit: add SPI support

src/machine/board_maixbit.go

@@ -2,52 +2,56 @@
 
 package machine
 
-// GPIO pins.
+// Pins on the MAix Bit.
 const (
-	D0 = P08
+	D0  = P00 // JTAG_TCLK
-	D1 = P09
+	D1  = P01 // JTAG_TDI
-	D2 = P10
+	D2  = P02 // JTAG_TMS
-	D3 = P11
+	D3  = P03 // JTAG_TDO
-	D4 = P12
+	D4  = P04 // UARTHS_RX
-	D5 = P13
+	D5  = P05 // UARTHS_TX
-	D6 = P14
+	D6  = P06 // RESV0
-	D7 = P15
+	D7  = P07 // RESV0
-)
+	D8  = P08 // GPIO1
-
+	D9  = P09 // GPIO2
-// High-speed GPIO pins (GPIOHS).
+	D10 = P10 // GPIO3
-const (
+	D11 = P11 // GPIO4
-	DHS0  = P16
+	D12 = P12 // GPIO5
-	DHS1  = P17
+	D13 = P13 // GPIO6
-	DHS2  = P18
+	D14 = P14 // GPIO7
-	DHS3  = P19
+	D15 = P15 // GPIO8
-	DHS4  = P20
+	D16 = P16 // GPIOHS0
-	DHS5  = P21
+	D17 = P17 // GPIOHS1
-	DHS6  = P22
+	D18 = P18 // GPIOHS2
-	DHS7  = P23
+	D19 = P19 // GPIOHS3
-	DHS8  = P24
+	D20 = P20 // GPIOHS4
-	DHS9  = P25
+	D21 = P21 // GPIOHS5
-	DHS10 = P26
+	D22 = P22 // GPIOHS6
-	DHS11 = P27
+	D23 = P23 // GPIOHS7
-	DHS12 = P28
+	D24 = P24 // GPIOHS8
-	DHS13 = P29
+	D25 = P25 // GPIOHS9
-	DHS14 = P30
+	D26 = P26 // GPIOHS10 / SPI0_MISO
-	DHS15 = P31
+	D27 = P27 // GPIOHS11 / SPI0_SCLK
-	DHS16 = P32
+	D28 = P28 // GPIOHS12 / SPI0_MOSI
-	DHS17 = P33
+	D29 = P29 // GPIOHS13
-	DHS18 = P34
+	D30 = P30 // GPIOHS14
-	DHS19 = P35
+	D31 = P31 // GPIOHS15
-	DHS20 = P36
+	D32 = P32 // GPIOHS16
-	DHS21 = P37
+	D33 = P33 // GPIOHS17
-	DHS22 = P38
+	D34 = P34 // GPIOHS18
-	DHS23 = P39
+	D35 = P35 // GPIOHS19
-	DHS24 = P40
+	D36 = P36 // GPIOHS20
-	DHS25 = P41
+	D37 = P37 // GPIOHS21
-	DHS26 = P42
+	D38 = P38 // GPIOHS22
-	DHS27 = P43
+	D39 = P39 // GPIOHS23
-	DHS28 = P44
+	D40 = P40 // GPIOHS24
-	DHS29 = P45
+	D41 = P41 // GPIOHS25
-	DHS30 = P46
+	D42 = P42 // GPIOHS26
-	DHS31 = P47
+	D43 = P43 // GPIOHS27
+	D44 = P44 // GPIOHS28
+	D45 = P45 // GPIOHS29
+	D46 = P46 // GPIOHS30
+	D47 = P47 // GPIOHS31
 )
 
 const (
@@ -55,13 +59,20 @@ const (
 	LED1      = LED_RED
 	LED2      = LED_GREEN
 	LED3      = LED_BLUE
-	LED_RED   = D5
+	LED_RED   = D13
-	LED_GREEN = D4
+	LED_GREEN = D12
-	LED_BLUE  = D6
+	LED_BLUE  = D14
 )
 
-// Default pins for UARTHS
+// Default pins for UARTHS.
 const (
-	UART_TX_PIN = P05
+	UART_TX_PIN = D5
-	UART_RX_PIN = P04
+	UART_RX_PIN = D4
+)
+
+// SPI pins.
+const (
+	SPI0_SCK_PIN  = D27
+	SPI0_MOSI_PIN = D28
+	SPI0_MISO_PIN = D26
 )

src/machine/board_maixbit_baremetal.go

@@ -0,0 +1,15 @@
+// +build k210,maixbit
+
+package machine
+
+import "device/kendryte"
+
+// SPI on the MAix Bit.
+var (
+	SPI0 = SPI{
+		Bus: kendryte.SPI0,
+	}
+	SPI1 = SPI{
+		Bus: kendryte.SPI1,
+	}
+)

src/machine/machine_k210.go

@@ -4,6 +4,7 @@ package machine
 
 import (
 	"device/kendryte"
+	"errors"
 	"runtime/interrupt"
 )
 
@@ -15,6 +16,7 @@ type PinMode uint8
 type fpioaPullMode uint8
 type PinChange uint8
 
+// Pin modes.
 const (
 	PinInput PinMode = iota
 	PinInputPullUp
@@ -22,12 +24,14 @@ const (
 	PinOutput
 )
 
+// FPIOA internal pull resistors.
 const (
 	fpioaPullNone fpioaPullMode = iota
 	fpioaPullDown
 	fpioaPullUp
 )
 
+// GPIOHS pin interrupt events.
 const (
 	PinRising PinChange = iota + 1
 	PinFalling
@@ -36,6 +40,20 @@ const (
 	PinLow = 8
 )
 
+// FPIOA functions.
+const (
+	fpioaFuncSpi0Sclk = 17
+	fpioaFuncSpi0D0   = 4
+	fpioaFuncSpi0D1   = 5
+	fpioaFuncSpi1Sclk = 83
+	fpioaFuncSpi1D0   = 70
+	fpioaFuncSpi1D1   = 71
+)
+
+var (
+	ErrUnsupportedSPIController = errors.New("SPI controller not supported. Use SPI0 or SPI1.")
+)
+
 func (p Pin) fpioaSetIOPull(pull fpioaPullMode) {
 	switch pull {
 	case fpioaPullNone:
@@ -340,3 +358,120 @@ func (uart UART) WriteByte(c byte) {
 
 	uart.Bus.TXDATA.Set(uint32(c))
 }
+
+type SPI struct {
+	Bus *kendryte.SPI_Type
+}
+
+// SPIConfig is used to store config info for SPI.
+type SPIConfig struct {
+	Frequency uint32
+	SCK       Pin
+	MOSI      Pin
+	MISO      Pin
+	LSBFirst  bool
+	Mode      uint8
+}
+
+// Configure is intended to setup the SPI interface.
+// Only SPI controller 0 and 1 can be used because SPI2 is a special
+// slave-mode controller and SPI3 is used for flashing.
+func (spi SPI) Configure(config SPIConfig) error {
+	// Use default pins if not set.
+	if config.SCK == 0 && config.MOSI == 0 && config.MISO == 0 {
+		config.SCK = SPI0_SCK_PIN
+		config.MOSI = SPI0_MOSI_PIN
+		config.MISO = SPI0_MISO_PIN
+	}
+
+	// Enable pins for SPI.
+	sckBits := uint32(kendryte.FPIOA_IO_OE_EN | kendryte.FPIOA_IO_DS_Msk)
+	dataBits := uint32(kendryte.FPIOA_IO_OE_EN | kendryte.FPIOA_IO_OE_INV | kendryte.FPIOA_IO_IE_EN |
+		kendryte.FPIOA_IO_IE_INV | kendryte.FPIOA_IO_ST | kendryte.FPIOA_IO_DS_Msk)
+
+	// Enable APB2 clock.
+	kendryte.SYSCTL.CLK_EN_CENT.SetBits(kendryte.SYSCTL_CLK_EN_CENT_APB2_CLK_EN)
+
+	var fpioaFuncSclk uint32
+	var fpioaFuncD0 uint32
+	var fpioaFuncD1 uint32
+
+	switch spi.Bus {
+	case kendryte.SPI0:
+		// Initialize FPIOA values.
+		fpioaFuncSclk = fpioaFuncSpi0Sclk
+		fpioaFuncD0 = fpioaFuncSpi0D0
+		fpioaFuncD1 = fpioaFuncSpi0D1
+
+		// Initialize SPI clock.
+		kendryte.SYSCTL.CLK_EN_PERI.SetBits(kendryte.SYSCTL_CLK_EN_PERI_SPI0_CLK_EN)
+		kendryte.SYSCTL.CLK_TH1.ClearBits(kendryte.SYSCTL_CLK_TH1_SPI0_CLK_Msk)
+	case kendryte.SPI1:
+		// Initialize FPIOA values.
+		fpioaFuncSclk = fpioaFuncSpi1Sclk
+		fpioaFuncD0 = fpioaFuncSpi1D0
+		fpioaFuncD1 = fpioaFuncSpi1D1
+
+		// Initialize SPI clock.
+		kendryte.SYSCTL.CLK_EN_PERI.SetBits(kendryte.SYSCTL_CLK_EN_PERI_SPI1_CLK_EN)
+		kendryte.SYSCTL.CLK_TH1.ClearBits(kendryte.SYSCTL_CLK_TH1_SPI1_CLK_Msk)
+	default:
+		return ErrUnsupportedSPIController
+	}
+
+	// Set FPIOA functins for selected pins.
+	kendryte.FPIOA.IO[uint8(config.SCK)].Set(uint32(sckBits | fpioaFuncSclk))
+	kendryte.FPIOA.IO[uint8(config.MOSI)].Set(uint32(dataBits | fpioaFuncD0))
+	kendryte.FPIOA.IO[uint8(config.MISO)].Set(uint32(dataBits | fpioaFuncD1))
+
+	// Set default frequency.
+	if config.Frequency == 0 {
+		config.Frequency = 500000
+	}
+
+	baudr := CPUFrequency() / config.Frequency
+	print(baudr)
+	spi.Bus.BAUDR.Set(baudr)
+
+	// Configure SPI mode 0, standard frame format, 8-bit data, little-endian.
+	spi.Bus.IMR.Set(0)
+	spi.Bus.DMACR.Set(0)
+	spi.Bus.DMATDLR.Set(0x10)
+	spi.Bus.DMARDLR.Set(0)
+	spi.Bus.SER.Set(0)
+	spi.Bus.SSIENR.Set(0)
+	spi.Bus.CTRLR0.Set((7 << 16))
+	spi.Bus.SPI_CTRLR0.Set(0)
+	spi.Bus.ENDIAN.Set(0)
+
+	return nil
+}
+
+// Transfer writes/reads a single byte using the SPI interface.
+func (spi SPI) Transfer(w byte) (byte, error) {
+	spi.Bus.SSIENR.Set(0)
+
+	// Set transfer-receive mode.
+	spi.Bus.CTRLR0.ClearBits(0x3 << 8)
+
+	// Enable/disable SPI.
+	spi.Bus.SSIENR.Set(1)
+	defer spi.Bus.SSIENR.Set(0)
+
+	// Enable/disable device.
+	spi.Bus.SER.Set(0x1)
+	defer spi.Bus.SER.Set(0)
+
+	spi.Bus.DR0.Set(uint32(w))
+
+	// Wait for transfer.
+	for spi.Bus.SR.Get()&0x05 != 0x04 {
+	}
+
+	// Wait for data.
+	for spi.Bus.RXFLR.Get() == 0 {
+	}
+
+	return byte(spi.Bus.DR0.Get()), nil
+
+}

src/machine/spi.go

@@ -1,4 +1,4 @@
-// +build !baremetal sam stm32 fe310
+// +build !baremetal sam stm32 fe310 k210
 
 package machine