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|
//go:build esp32c3
package machine
import (
"device/esp"
"device/riscv"
"errors"
"runtime/interrupt"
"runtime/volatile"
"sync"
"unsafe"
)
const deviceName = esp.Device
const maxPin = 22
const cpuInterruptFromPin = 6
// CPUFrequency returns the current CPU frequency of the chip.
// Currently it is a fixed frequency but it may allow changing in the future.
func CPUFrequency() uint32 {
return 160e6 // 160MHz
}
const (
PinOutput PinMode = iota
PinInput
PinInputPullup
PinInputPulldown
)
const (
GPIO0 Pin = 0
GPIO1 Pin = 1
GPIO2 Pin = 2
GPIO3 Pin = 3
GPIO4 Pin = 4
GPIO5 Pin = 5
GPIO6 Pin = 6
GPIO7 Pin = 7
GPIO8 Pin = 8
GPIO9 Pin = 9
GPIO10 Pin = 10
GPIO11 Pin = 11
GPIO12 Pin = 12
GPIO13 Pin = 13
GPIO14 Pin = 14
GPIO15 Pin = 15
GPIO16 Pin = 16
GPIO17 Pin = 17
GPIO18 Pin = 18
GPIO19 Pin = 19
GPIO20 Pin = 20
GPIO21 Pin = 21
)
type PinChange uint8
// Pin change interrupt constants for SetInterrupt.
const (
PinRising PinChange = iota + 1
PinFalling
PinToggle
)
// Configure this pin with the given configuration.
func (p Pin) Configure(config PinConfig) {
if p == NoPin {
// This simplifies pin configuration in peripherals such as SPI.
return
}
var muxConfig uint32
// Configure this pin as a GPIO pin.
const function = 1 // function 1 is GPIO for every pin
muxConfig |= function << esp.IO_MUX_GPIO_MCU_SEL_Pos
// Make this pin an input pin (always).
muxConfig |= esp.IO_MUX_GPIO_FUN_IE
// Set drive strength: 0 is lowest, 3 is highest.
muxConfig |= 2 << esp.IO_MUX_GPIO_FUN_DRV_Pos
// Select pull mode.
if config.Mode == PinInputPullup {
muxConfig |= esp.IO_MUX_GPIO_FUN_WPU
} else if config.Mode == PinInputPulldown {
muxConfig |= esp.IO_MUX_GPIO_FUN_WPD
}
// Configure the pad with the given IO mux configuration.
p.mux().Set(muxConfig)
// Set the output signal to the simple GPIO output.
p.outFunc().Set(0x80)
switch config.Mode {
case PinOutput:
// Set the 'output enable' bit.
esp.GPIO.ENABLE_W1TS.Set(1 << p)
case PinInput, PinInputPullup, PinInputPulldown:
// Clear the 'output enable' bit.
esp.GPIO.ENABLE_W1TC.Set(1 << p)
}
}
// outFunc returns the FUNCx_OUT_SEL_CFG register used for configuring the
// output function selection.
func (p Pin) outFunc() *volatile.Register32 {
return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(&esp.GPIO.FUNC0_OUT_SEL_CFG), uintptr(p)*4))
}
func (p Pin) pinReg() *volatile.Register32 {
return (*volatile.Register32)(unsafe.Pointer((uintptr(unsafe.Pointer(&esp.GPIO.PIN0)) + uintptr(p)*4)))
}
// inFunc returns the FUNCy_IN_SEL_CFG register used for configuring the input
// function selection.
func inFunc(signal uint32) *volatile.Register32 {
return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(&esp.GPIO.FUNC0_IN_SEL_CFG), uintptr(signal)*4))
}
// mux returns the I/O mux configuration register corresponding to the given
// GPIO pin.
func (p Pin) mux() *volatile.Register32 {
return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(&esp.IO_MUX.GPIO0), uintptr(p)*4))
}
// pin returns the PIN register corresponding to the given GPIO pin.
func (p Pin) pin() *volatile.Register32 {
return (*volatile.Register32)(unsafe.Add(unsafe.Pointer(&esp.GPIO.PIN0), uintptr(p)*4))
}
// Set the pin to high or low.
// Warning: only use this on an output pin!
func (p Pin) Set(value bool) {
if value {
reg, mask := p.portMaskSet()
reg.Set(mask)
} else {
reg, mask := p.portMaskClear()
reg.Set(mask)
}
}
// Get returns the current value of a GPIO pin when configured as an input or as
// an output.
func (p Pin) Get() bool {
reg := &esp.GPIO.IN
return (reg.Get()>>p)&1 > 0
}
// Return the register and mask to enable a given GPIO pin. This can be used to
// implement bit-banged drivers.
//
// Warning: only use this on an output pin!
func (p Pin) PortMaskSet() (*uint32, uint32) {
reg, mask := p.portMaskSet()
return ®.Reg, mask
}
// Return the register and mask to disable a given GPIO pin. This can be used to
// implement bit-banged drivers.
//
// Warning: only use this on an output pin!
func (p Pin) PortMaskClear() (*uint32, uint32) {
reg, mask := p.portMaskClear()
return ®.Reg, mask
}
func (p Pin) portMaskSet() (*volatile.Register32, uint32) {
return &esp.GPIO.OUT_W1TS, 1 << p
}
func (p Pin) portMaskClear() (*volatile.Register32, uint32) {
return &esp.GPIO.OUT_W1TC, 1 << p
}
// SetInterrupt sets an interrupt to be executed when a particular pin changes
// state. The pin should already be configured as an input, including a pull up
// or down if no external pull is provided.
//
// You can pass a nil func to unset the pin change interrupt. If you do so,
// the change parameter is ignored and can be set to any value (such as 0).
// If the pin is already configured with a callback, you must first unset
// this pins interrupt before you can set a new callback.
func (p Pin) SetInterrupt(change PinChange, callback func(Pin)) (err error) {
if p >= maxPin {
return ErrInvalidInputPin
}
if callback == nil {
// Disable this pin interrupt
p.pin().ClearBits(esp.GPIO_PIN_INT_TYPE_Msk | esp.GPIO_PIN_INT_ENA_Msk)
if pinCallbacks[p] != nil {
pinCallbacks[p] = nil
}
return nil
}
if pinCallbacks[p] != nil {
// The pin was already configured.
// To properly re-configure a pin, unset it first and set a new
// configuration.
return ErrNoPinChangeChannel
}
pinCallbacks[p] = callback
onceSetupPinInterrupt.Do(func() {
err = setupPinInterrupt()
})
if err != nil {
return err
}
p.pin().Set(
(p.pin().Get() & ^uint32(esp.GPIO_PIN_INT_TYPE_Msk|esp.GPIO_PIN_INT_ENA_Msk)) |
uint32(change)<<esp.GPIO_PIN_INT_TYPE_Pos | uint32(1)<<esp.GPIO_PIN_INT_ENA_Pos)
return nil
}
var (
pinCallbacks [maxPin]func(Pin)
onceSetupPinInterrupt sync.Once
)
func setupPinInterrupt() error {
esp.INTERRUPT_CORE0.GPIO_INTERRUPT_PRO_MAP.Set(cpuInterruptFromPin)
return interrupt.New(cpuInterruptFromPin, func(interrupt.Interrupt) {
status := esp.GPIO.STATUS.Get()
for i, mask := 0, uint32(1); i < maxPin; i, mask = i+1, mask<<1 {
if (status&mask) != 0 && pinCallbacks[i] != nil {
pinCallbacks[i](Pin(i))
}
}
// clear interrupt bit
esp.GPIO.STATUS_W1TC.SetBits(status)
}).Enable()
}
var (
DefaultUART = UART0
UART0 = &_UART0
_UART0 = UART{Bus: esp.UART0, Buffer: NewRingBuffer()}
UART1 = &_UART1
_UART1 = UART{Bus: esp.UART1, Buffer: NewRingBuffer()}
onceUart = sync.Once{}
errSamePins = errors.New("UART: invalid pin combination")
errWrongUART = errors.New("UART: unsupported UARTn")
errWrongBitSize = errors.New("UART: invalid data size")
errWrongStopBitSize = errors.New("UART: invalid bit size")
)
type UART struct {
Bus *esp.UART_Type
Buffer *RingBuffer
ParityErrorDetected bool // set when parity error detected
DataErrorDetected bool // set when data corruption detected
DataOverflowDetected bool // set when data overflow detected in UART FIFO buffer or RingBuffer
}
const (
defaultDataBits = 8
defaultStopBit = 1
defaultParity = ParityNone
uartInterrupts = esp.UART_INT_ENA_RXFIFO_FULL_INT_ENA |
esp.UART_INT_ENA_PARITY_ERR_INT_ENA |
esp.UART_INT_ENA_FRM_ERR_INT_ENA |
esp.UART_INT_ENA_RXFIFO_OVF_INT_ENA |
esp.UART_INT_ENA_GLITCH_DET_INT_ENA
pplClockFreq = 80e6
)
type registerSet struct {
interruptMapReg *volatile.Register32
uartClockBitMask uint32
gpioMatrixSignal uint32
}
func (uart *UART) Configure(config UARTConfig) error {
if config.BaudRate == 0 {
config.BaudRate = 115200
}
if config.TX == config.RX {
return errSamePins
}
switch {
case uart.Bus == esp.UART0:
return uart.configure(config, registerSet{
interruptMapReg: &esp.INTERRUPT_CORE0.UART_INTR_MAP,
uartClockBitMask: esp.SYSTEM_PERIP_CLK_EN0_UART_CLK_EN,
gpioMatrixSignal: 6,
})
case uart.Bus == esp.UART1:
return uart.configure(config, registerSet{
interruptMapReg: &esp.INTERRUPT_CORE0.UART1_INTR_MAP,
uartClockBitMask: esp.SYSTEM_PERIP_CLK_EN0_UART1_CLK_EN,
gpioMatrixSignal: 9,
})
}
return errWrongUART
}
func (uart *UART) configure(config UARTConfig, regs registerSet) error {
initUARTClock(uart.Bus, regs)
// - disable TX/RX clock to make sure the UART transmitter or receiver is not at work during configuration
uart.Bus.SetCLK_CONF_TX_SCLK_EN(0)
uart.Bus.SetCLK_CONF_RX_SCLK_EN(0)
// Configure static registers (Ref: Configuring URATn Communication)
// - default clock source: 1=APB_CLK, 2=FOSC_CLK, 3=XTAL_CLK
uart.Bus.SetCLK_CONF_SCLK_SEL(1)
// reset divisor of the divider via UART_SCLK_DIV_NUM, UART_SCLK_DIV_A, and UART_SCLK_DIV_B
uart.Bus.SetCLK_CONF_SCLK_DIV_NUM(0)
uart.Bus.SetCLK_CONF_SCLK_DIV_A(0)
uart.Bus.SetCLK_CONF_SCLK_DIV_B(0)
// - the baud rate
uart.SetBaudRate(config.BaudRate)
// - the data format
uart.SetFormat(defaultDataBits, defaultStopBit, defaultParity)
// - set UART mode
uart.Bus.SetRS485_CONF_RS485_EN(0)
uart.Bus.SetRS485_CONF_RS485TX_RX_EN(0)
uart.Bus.SetRS485_CONF_RS485RXBY_TX_EN(0)
uart.Bus.SetCONF0_IRDA_EN(0)
// - disable hw-flow control
uart.Bus.SetCONF0_TX_FLOW_EN(0)
uart.Bus.SetCONF1_RX_FLOW_EN(0)
// synchronize values into Core Clock
uart.Bus.SetID_REG_UPDATE(1)
uart.setupPins(config, regs)
uart.configureInterrupt(regs.interruptMapReg)
uart.enableTransmitter()
uart.enableReceiver()
// Start TX/RX
uart.Bus.SetCLK_CONF_TX_SCLK_EN(1)
uart.Bus.SetCLK_CONF_RX_SCLK_EN(1)
return nil
}
func (uart *UART) SetFormat(dataBits, stopBits int, parity UARTParity) error {
if dataBits < 5 {
return errWrongBitSize
}
if stopBits > 1 {
return errWrongStopBitSize
}
// - data length
uart.Bus.SetCONF0_BIT_NUM(uint32(dataBits - 5))
// - stop bit
uart.Bus.SetCONF0_STOP_BIT_NUM(uint32(stopBits))
// - parity check
switch parity {
case ParityNone:
uart.Bus.SetCONF0_PARITY_EN(0)
case ParityEven:
uart.Bus.SetCONF0_PARITY_EN(1)
uart.Bus.SetCONF0_PARITY(0)
case ParityOdd:
uart.Bus.SetCONF0_PARITY_EN(1)
uart.Bus.SetCONF0_PARITY(1)
}
return nil
}
func initUARTClock(bus *esp.UART_Type, regs registerSet) {
uartClock := &esp.SYSTEM.PERIP_CLK_EN0
uartClockReset := &esp.SYSTEM.PERIP_RST_EN0
// Initialize/reset URATn (Ref: Initializing URATn)
// - enable the clock for UART RAM
uartClock.SetBits(esp.SYSTEM_PERIP_CLK_EN0_UART_MEM_CLK_EN)
// - enable APB_CLK for UARTn
uartClock.SetBits(regs.uartClockBitMask)
// - reset sequence
uartClockReset.ClearBits(regs.uartClockBitMask)
bus.SetCLK_CONF_RST_CORE(1)
uartClockReset.SetBits(regs.uartClockBitMask)
uartClockReset.ClearBits(regs.uartClockBitMask)
bus.SetCLK_CONF_RST_CORE(0)
// synchronize core register
bus.SetID_REG_UPDATE(0)
// enable RTC clock
esp.RTC_CNTL.SetCLK_CONF_DIG_CLK8M_EN(1)
// wait for Core Clock to ready for configuration
for bus.GetID_REG_UPDATE() > 0 {
riscv.Asm("nop")
}
}
func (uart *UART) SetBaudRate(baudRate uint32) {
// based on esp-idf
max_div := uint32((1 << 12) - 1)
sclk_div := (pplClockFreq + (max_div * baudRate) - 1) / (max_div * baudRate)
clk_div := (pplClockFreq << 4) / (baudRate * sclk_div)
uart.Bus.SetCLKDIV(clk_div >> 4)
uart.Bus.SetCLKDIV_FRAG(clk_div & 0xf)
uart.Bus.SetCLK_CONF_SCLK_DIV_NUM(sclk_div - 1)
}
func (uart *UART) setupPins(config UARTConfig, regs registerSet) {
config.RX.Configure(PinConfig{Mode: PinInputPullup})
config.TX.Configure(PinConfig{Mode: PinInputPullup})
// link TX with GPIO signal X (technical reference manual 5.10) (this is not interrupt signal!)
config.TX.outFunc().Set(regs.gpioMatrixSignal)
// link RX with GPIO signal X and route signals via GPIO matrix (GPIO_SIGn_IN_SEL 0x40)
inFunc(regs.gpioMatrixSignal).Set(esp.GPIO_FUNC_IN_SEL_CFG_SEL | uint32(config.RX))
}
func (uart *UART) configureInterrupt(intrMapReg *volatile.Register32) { // Disable all UART interrupts
// Disable all UART interrupts
uart.Bus.INT_ENA.ClearBits(0x0ffff)
intrMapReg.Set(7)
onceUart.Do(func() {
_ = interrupt.New(7, func(i interrupt.Interrupt) {
UART0.serveInterrupt(0)
UART1.serveInterrupt(1)
}).Enable()
})
}
func (uart *UART) serveInterrupt(num int) {
// get interrupt status
interrutFlag := uart.Bus.INT_ST.Get()
if (interrutFlag & uartInterrupts) == 0 {
return
}
// block UART interrupts while processing
uart.Bus.INT_ENA.ClearBits(uartInterrupts)
if interrutFlag&esp.UART_INT_ENA_RXFIFO_FULL_INT_ENA > 0 {
for uart.Bus.GetSTATUS_RXFIFO_CNT() > 0 {
b := uart.Bus.GetFIFO_RXFIFO_RD_BYTE()
if !uart.Buffer.Put(byte(b & 0xff)) {
uart.DataOverflowDetected = true
}
}
}
if interrutFlag&esp.UART_INT_ENA_PARITY_ERR_INT_ENA > 0 {
uart.ParityErrorDetected = true
}
if 0 != interrutFlag&esp.UART_INT_ENA_FRM_ERR_INT_ENA {
uart.DataErrorDetected = true
}
if 0 != interrutFlag&esp.UART_INT_ENA_RXFIFO_OVF_INT_ENA {
uart.DataOverflowDetected = true
}
if 0 != interrutFlag&esp.UART_INT_ENA_GLITCH_DET_INT_ENA {
uart.DataErrorDetected = true
}
// Clear the UART interrupt status
uart.Bus.INT_CLR.SetBits(interrutFlag)
uart.Bus.INT_CLR.ClearBits(interrutFlag)
// Enable interrupts
uart.Bus.INT_ENA.Set(uartInterrupts)
}
const uart_empty_thresh_default = 10
func (uart *UART) enableTransmitter() {
uart.Bus.SetCONF0_TXFIFO_RST(1)
uart.Bus.SetCONF0_TXFIFO_RST(0)
// TXINFO empty threshold is when txfifo_empty_int interrupt produced after the amount of data in Tx-FIFO is less than this register value.
uart.Bus.SetCONF1_TXFIFO_EMPTY_THRHD(uart_empty_thresh_default)
// we are not using interrupt on TX since write we are waiting for FIFO to have space.
// uart.Bus.INT_ENA.SetBits(esp.UART_INT_ENA_TXFIFO_EMPTY_INT_ENA)
}
func (uart *UART) enableReceiver() {
uart.Bus.SetCONF0_RXFIFO_RST(1)
uart.Bus.SetCONF0_RXFIFO_RST(0)
// using value 1 so that we can start populate ring buffer with data as we get it
uart.Bus.SetCONF1_RXFIFO_FULL_THRHD(1)
// enable interrupts for:
uart.Bus.SetINT_ENA_RXFIFO_FULL_INT_ENA(1)
uart.Bus.SetINT_ENA_FRM_ERR_INT_ENA(1)
uart.Bus.SetINT_ENA_PARITY_ERR_INT_ENA(1)
uart.Bus.SetINT_ENA_GLITCH_DET_INT_ENA(1)
uart.Bus.SetINT_ENA_RXFIFO_OVF_INT_ENA(1)
}
func (uart *UART) writeByte(b byte) error {
for (uart.Bus.STATUS.Get()&esp.UART_STATUS_TXFIFO_CNT_Msk)>>esp.UART_STATUS_TXFIFO_CNT_Pos >= 128 {
// Read UART_TXFIFO_CNT from the status register, which indicates how
// many bytes there are in the transmit buffer. Wait until there are
// less than 128 bytes in this buffer (the default buffer size).
}
uart.Bus.FIFO.Set(uint32(b))
return nil
}
func (uart *UART) flush() {}
type Serialer interface {
WriteByte(c byte) error
Write(data []byte) (n int, err error)
Configure(config UARTConfig) error
Buffered() int
ReadByte() (byte, error)
DTR() bool
RTS() bool
}
// USB Serial/JTAG Controller
// See esp32-c3_technical_reference_manual_en.pdf
// pg. 736
type USB_DEVICE struct {
Bus *esp.USB_DEVICE_Type
}
var (
_USBCDC = &USB_DEVICE{
Bus: esp.USB_DEVICE,
}
USBCDC Serialer = _USBCDC
)
var (
errUSBWrongSize = errors.New("USB: invalid write size")
errUSBCouldNotWriteAllData = errors.New("USB: could not write all data")
errUSBBufferEmpty = errors.New("USB: read buffer empty")
)
func (usbdev *USB_DEVICE) Configure(config UARTConfig) error {
return nil
}
func (usbdev *USB_DEVICE) WriteByte(c byte) error {
if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
return errUSBCouldNotWriteAllData
}
usbdev.Bus.SetEP1_RDWR_BYTE(uint32(c))
usbdev.flush()
return nil
}
func (usbdev *USB_DEVICE) Write(data []byte) (n int, err error) {
if len(data) == 0 || len(data) > 64 {
return 0, errUSBWrongSize
}
for i, c := range data {
if usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
if i > 0 {
usbdev.flush()
}
return i, errUSBCouldNotWriteAllData
}
usbdev.Bus.SetEP1_RDWR_BYTE(uint32(c))
}
usbdev.flush()
return len(data), nil
}
func (usbdev *USB_DEVICE) Buffered() int {
return int(usbdev.Bus.GetEP1_CONF_SERIAL_OUT_EP_DATA_AVAIL())
}
func (usbdev *USB_DEVICE) ReadByte() (byte, error) {
if usbdev.Bus.GetEP1_CONF_SERIAL_OUT_EP_DATA_AVAIL() != 0 {
return byte(usbdev.Bus.GetEP1_RDWR_BYTE()), nil
}
return 0, nil
}
func (usbdev *USB_DEVICE) DTR() bool {
return false
}
func (usbdev *USB_DEVICE) RTS() bool {
return false
}
func (usbdev *USB_DEVICE) flush() {
usbdev.Bus.SetEP1_CONF_WR_DONE(1)
for usbdev.Bus.GetEP1_CONF_SERIAL_IN_EP_DATA_FREE() == 0 {
}
}
// GetRNG returns 32-bit random numbers using the ESP32-C3 true random number generator,
// Random numbers are generated based on the thermal noise in the system and the
// asynchronous clock mismatch.
// For maximum entropy also make sure that the SAR_ADC is enabled.
// See esp32-c3_technical_reference_manual_en.pdf p.524
func GetRNG() (ret uint32, err error) {
// ensure ADC clock is initialized
initADCClock()
// ensure fast RTC clock is enabled
if esp.RTC_CNTL.GetCLK_CONF_DIG_CLK8M_EN() == 0 {
esp.RTC_CNTL.SetCLK_CONF_DIG_CLK8M_EN(1)
}
return esp.APB_CTRL.GetRND_DATA(), nil
}
func initADCClock() {
if esp.APB_SARADC.GetCLKM_CONF_CLK_EN() == 1 {
return
}
// only support ADC_CTRL_CLK set to 1
esp.APB_SARADC.SetCLKM_CONF_CLK_SEL(1)
esp.APB_SARADC.SetCTRL_SARADC_SAR_CLK_GATED(1)
esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_NUM(15)
esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_B(1)
esp.APB_SARADC.SetCLKM_CONF_CLKM_DIV_A(0)
esp.APB_SARADC.SetCTRL_SARADC_SAR_CLK_DIV(1)
esp.APB_SARADC.SetCLKM_CONF_CLK_EN(1)
}
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