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|
//go:build k210
package machine
import (
"device/kendryte"
"device/riscv"
"errors"
"runtime/interrupt"
"unsafe"
)
const deviceName = kendryte.Device
func CPUFrequency() uint32 {
return 390000000
}
type fpioaPullMode uint8
type PinChange uint8
// Pin modes.
const (
PinInput PinMode = iota
PinInputPullup
PinInputPulldown
PinOutput
)
// Deprecated: use PinInputPullup and PinInputPulldown instead.
const (
PinInputPullUp = PinInputPullup
PinInputPullDown = PinInputPulldown
)
// FPIOA internal pull resistors.
const (
fpioaPullNone fpioaPullMode = iota
fpioaPullDown
fpioaPullUp
)
// GPIOHS pin interrupt events.
const (
PinRising PinChange = 1 << iota
PinFalling
PinToggle = PinRising | PinFalling
)
var (
errUnsupportedSPIController = errors.New("SPI controller not supported. Use SPI0 or SPI1.")
errI2CTxAbort = errors.New("I2C transmission has been aborted.")
)
func (p Pin) setFPIOAIOPull(pull fpioaPullMode) {
switch pull {
case fpioaPullNone:
kendryte.FPIOA.IO[uint8(p)].ClearBits(kendryte.FPIOA_IO_PU & kendryte.FPIOA_IO_PD)
case fpioaPullUp:
kendryte.FPIOA.IO[uint8(p)].SetBits(kendryte.FPIOA_IO_PU)
kendryte.FPIOA.IO[uint8(p)].ClearBits(kendryte.FPIOA_IO_PD)
case fpioaPullDown:
kendryte.FPIOA.IO[uint8(p)].ClearBits(kendryte.FPIOA_IO_PU)
kendryte.FPIOA.IO[uint8(p)].SetBits(kendryte.FPIOA_IO_PD)
}
}
// SetFPIOAFunction is used to configure the pin for one of the FPIOA functions.
// Each pin on the Kendryte K210 can be configured with any of the available FPIOA functions.
func (p Pin) SetFPIOAFunction(f FPIOAFunction) {
kendryte.FPIOA.IO[uint8(p)].Set(fpioaFuncDefaults[uint8(f)])
}
// FPIOAFunction returns the current FPIOA function of the pin.
func (p Pin) FPIOAFunction() FPIOAFunction {
return FPIOAFunction((kendryte.FPIOA.IO[uint8(p)].Get() & kendryte.FPIOA_IO_CH_SEL_Msk))
}
// Configure this pin with the given configuration.
// The pin must already be set as GPIO or GPIOHS pin.
func (p Pin) Configure(config PinConfig) {
var input bool
// Check if the current pin's FPIOA function is either GPIO or GPIOHS.
f := p.FPIOAFunction()
if f < FUNC_GPIOHS0 || f > FUNC_GPIO7 {
return // The pin is not configured as GPIO or GPIOHS.
}
// Configure pin.
kendryte.FPIOA.IO[uint8(p)].SetBits(kendryte.FPIOA_IO_OE_EN | kendryte.FPIOA_IO_IE_EN | kendryte.FPIOA_IO_ST | kendryte.FPIOA_IO_DS_Msk)
switch config.Mode {
case PinInput:
p.setFPIOAIOPull(fpioaPullNone)
input = true
case PinInputPullup:
p.setFPIOAIOPull(fpioaPullUp)
input = true
case PinInputPulldown:
p.setFPIOAIOPull(fpioaPullDown)
input = true
case PinOutput:
p.setFPIOAIOPull(fpioaPullNone)
input = false
}
if f >= FUNC_GPIO0 && f <= FUNC_GPIO7 {
// Converts the IO pin number in the effective GPIO number (based on the FPIOA function).
gpioPin := uint8(f - FUNC_GPIO0)
if input {
kendryte.GPIO.DIRECTION.ClearBits(1 << gpioPin)
} else {
kendryte.GPIO.DIRECTION.SetBits(1 << gpioPin)
}
} else if f >= FUNC_GPIOHS0 && f <= FUNC_GPIOHS31 {
// Converts the IO pin number in the effective GPIOHS number (based on the FPIOA function).
gpioPin := uint8(f - FUNC_GPIOHS0)
if input {
kendryte.GPIOHS.INPUT_EN.SetBits(1 << gpioPin)
kendryte.GPIOHS.OUTPUT_EN.ClearBits(1 << gpioPin)
} else {
kendryte.GPIOHS.OUTPUT_EN.SetBits(1 << gpioPin)
kendryte.GPIOHS.INPUT_EN.ClearBits(1 << gpioPin)
}
}
}
// Set the pin to high or low.
func (p Pin) Set(high bool) {
// Check if the current pin's FPIOA function is either GPIO or GPIOHS.
f := p.FPIOAFunction()
if f < FUNC_GPIOHS0 || f > FUNC_GPIO7 {
return // The pin is not configured as GPIO or GPIOHS.
}
if f >= FUNC_GPIO0 && f <= FUNC_GPIO7 {
gpioPin := uint8(f - FUNC_GPIO0)
if high {
kendryte.GPIO.DATA_OUTPUT.SetBits(1 << gpioPin)
} else {
kendryte.GPIO.DATA_OUTPUT.ClearBits(1 << gpioPin)
}
} else if f >= FUNC_GPIOHS0 && f <= FUNC_GPIOHS31 {
gpioPin := uint8(f - FUNC_GPIOHS0)
if high {
kendryte.GPIOHS.OUTPUT_VAL.SetBits(1 << gpioPin)
} else {
kendryte.GPIOHS.OUTPUT_VAL.ClearBits(1 << gpioPin)
}
}
}
// Get returns the current value of a GPIO pin.
func (p Pin) Get() bool {
// Check if the current pin's FPIOA function is either GPIO or GPIOHS.
f := p.FPIOAFunction()
if f < FUNC_GPIOHS0 || f > FUNC_GPIO7 {
return false // The pin is not configured as GPIO or GPIOHS.
}
var val uint32
if f >= FUNC_GPIO0 && f <= FUNC_GPIO7 {
gpioPin := uint8(f - FUNC_GPIO0)
val = kendryte.GPIO.DATA_INPUT.Get() & (1 << gpioPin)
} else if f >= FUNC_GPIOHS0 && f <= FUNC_GPIOHS31 {
gpioPin := uint8(f - FUNC_GPIOHS0)
val = kendryte.GPIOHS.INPUT_VAL.Get() & (1 << gpioPin)
}
return (val > 0)
}
// Callbacks to be called for GPIOHS pins configured with SetInterrupt.
var pinCallbacks [32]func(Pin)
// 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)) error {
// Check if the pin is a GPIOHS pin.
f := p.FPIOAFunction()
if f < FUNC_GPIOHS0 || f > FUNC_GPIOHS31 {
return ErrInvalidDataPin
}
gpioPin := uint8(f - FUNC_GPIOHS0)
// Clear all interrupts.
kendryte.GPIOHS.RISE_IE.ClearBits(1 << gpioPin)
kendryte.GPIOHS.FALL_IE.ClearBits(1 << gpioPin)
kendryte.GPIOHS.HIGH_IE.ClearBits(1 << gpioPin)
kendryte.GPIOHS.LOW_IE.ClearBits(1 << gpioPin)
// Clear all the pending bits for this pin.
kendryte.GPIOHS.RISE_IP.SetBits(1 << gpioPin)
kendryte.GPIOHS.FALL_IP.SetBits(1 << gpioPin)
kendryte.GPIOHS.HIGH_IP.SetBits(1 << gpioPin)
kendryte.GPIOHS.LOW_IP.SetBits(1 << gpioPin)
if callback == nil {
if pinCallbacks[gpioPin] != nil {
pinCallbacks[gpioPin] = nil
}
return nil
}
if pinCallbacks[gpioPin] != nil {
// The pin was already configured.
// To properly re-configure a pin, unset it first and set a new
// configuration.
return ErrNoPinChangeChannel
}
pinCallbacks[gpioPin] = callback
// Enable interrupts.
if change&PinRising != 0 {
kendryte.GPIOHS.RISE_IE.SetBits(1 << gpioPin)
}
if change&PinFalling != 0 {
kendryte.GPIOHS.FALL_IE.SetBits(1 << gpioPin)
}
handleInterrupt := func(inter interrupt.Interrupt) {
pin := uint8(inter.GetNumber() - kendryte.IRQ_GPIOHS0)
if kendryte.GPIOHS.RISE_IE.HasBits(1 << pin) {
kendryte.GPIOHS.RISE_IE.ClearBits(1 << pin)
// Acknowledge interrupt atomically.
riscv.AsmFull(
"amoor.w {}, {mask}, ({reg})",
map[string]interface{}{
"mask": uint32(1 << pin),
"reg": uintptr(unsafe.Pointer(&kendryte.GPIOHS.RISE_IP.Reg)),
})
kendryte.GPIOHS.RISE_IE.SetBits(1 << pin)
}
if kendryte.GPIOHS.FALL_IE.HasBits(1 << pin) {
kendryte.GPIOHS.FALL_IE.ClearBits(1 << pin)
// Acknowledge interrupt atomically.
riscv.AsmFull(
"amoor.w {}, {mask}, ({reg})",
map[string]interface{}{
"mask": uint32(1 << pin),
"reg": uintptr(unsafe.Pointer(&kendryte.GPIOHS.FALL_IP.Reg)),
})
kendryte.GPIOHS.FALL_IE.SetBits(1 << pin)
}
pinCallbacks[pin](Pin(pin))
}
var ir interrupt.Interrupt
switch f {
case FUNC_GPIOHS0:
ir = interrupt.New(kendryte.IRQ_GPIOHS0, handleInterrupt)
case FUNC_GPIOHS1:
ir = interrupt.New(kendryte.IRQ_GPIOHS1, handleInterrupt)
case FUNC_GPIOHS2:
ir = interrupt.New(kendryte.IRQ_GPIOHS2, handleInterrupt)
case FUNC_GPIOHS3:
ir = interrupt.New(kendryte.IRQ_GPIOHS3, handleInterrupt)
case FUNC_GPIOHS4:
ir = interrupt.New(kendryte.IRQ_GPIOHS4, handleInterrupt)
case FUNC_GPIOHS5:
ir = interrupt.New(kendryte.IRQ_GPIOHS5, handleInterrupt)
case FUNC_GPIOHS6:
ir = interrupt.New(kendryte.IRQ_GPIOHS6, handleInterrupt)
case FUNC_GPIOHS7:
ir = interrupt.New(kendryte.IRQ_GPIOHS7, handleInterrupt)
case FUNC_GPIOHS8:
ir = interrupt.New(kendryte.IRQ_GPIOHS8, handleInterrupt)
case FUNC_GPIOHS9:
ir = interrupt.New(kendryte.IRQ_GPIOHS9, handleInterrupt)
case FUNC_GPIOHS10:
ir = interrupt.New(kendryte.IRQ_GPIOHS10, handleInterrupt)
case FUNC_GPIOHS11:
ir = interrupt.New(kendryte.IRQ_GPIOHS11, handleInterrupt)
case FUNC_GPIOHS12:
ir = interrupt.New(kendryte.IRQ_GPIOHS12, handleInterrupt)
case FUNC_GPIOHS13:
ir = interrupt.New(kendryte.IRQ_GPIOHS13, handleInterrupt)
case FUNC_GPIOHS14:
ir = interrupt.New(kendryte.IRQ_GPIOHS14, handleInterrupt)
case FUNC_GPIOHS15:
ir = interrupt.New(kendryte.IRQ_GPIOHS15, handleInterrupt)
case FUNC_GPIOHS16:
ir = interrupt.New(kendryte.IRQ_GPIOHS16, handleInterrupt)
case FUNC_GPIOHS17:
ir = interrupt.New(kendryte.IRQ_GPIOHS17, handleInterrupt)
case FUNC_GPIOHS18:
ir = interrupt.New(kendryte.IRQ_GPIOHS18, handleInterrupt)
case FUNC_GPIOHS19:
ir = interrupt.New(kendryte.IRQ_GPIOHS19, handleInterrupt)
case FUNC_GPIOHS20:
ir = interrupt.New(kendryte.IRQ_GPIOHS20, handleInterrupt)
case FUNC_GPIOHS21:
ir = interrupt.New(kendryte.IRQ_GPIOHS21, handleInterrupt)
case FUNC_GPIOHS22:
ir = interrupt.New(kendryte.IRQ_GPIOHS22, handleInterrupt)
case FUNC_GPIOHS23:
ir = interrupt.New(kendryte.IRQ_GPIOHS23, handleInterrupt)
case FUNC_GPIOHS24:
ir = interrupt.New(kendryte.IRQ_GPIOHS24, handleInterrupt)
case FUNC_GPIOHS25:
ir = interrupt.New(kendryte.IRQ_GPIOHS25, handleInterrupt)
case FUNC_GPIOHS26:
ir = interrupt.New(kendryte.IRQ_GPIOHS26, handleInterrupt)
case FUNC_GPIOHS27:
ir = interrupt.New(kendryte.IRQ_GPIOHS27, handleInterrupt)
case FUNC_GPIOHS28:
ir = interrupt.New(kendryte.IRQ_GPIOHS28, handleInterrupt)
case FUNC_GPIOHS29:
ir = interrupt.New(kendryte.IRQ_GPIOHS29, handleInterrupt)
case FUNC_GPIOHS30:
ir = interrupt.New(kendryte.IRQ_GPIOHS30, handleInterrupt)
case FUNC_GPIOHS31:
ir = interrupt.New(kendryte.IRQ_GPIOHS31, handleInterrupt)
}
ir.SetPriority(5)
ir.Enable()
return nil
}
type UART struct {
Bus *kendryte.UARTHS_Type
Buffer *RingBuffer
}
var (
UART0 = &_UART0
_UART0 = UART{Bus: kendryte.UARTHS, Buffer: NewRingBuffer()}
)
func (uart *UART) Configure(config UARTConfig) {
// Use default baudrate if not set.
if config.BaudRate == 0 {
config.BaudRate = 115200
}
// Use default pins if not set.
if config.TX == 0 && config.RX == 0 {
config.TX = UART_TX_PIN
config.RX = UART_RX_PIN
}
config.TX.SetFPIOAFunction(FUNC_UARTHS_TX)
config.RX.SetFPIOAFunction(FUNC_UARTHS_RX)
div := CPUFrequency()/config.BaudRate - 1
uart.Bus.DIV.Set(div)
uart.Bus.TXCTRL.Set(kendryte.UARTHS_TXCTRL_TXEN)
uart.Bus.RXCTRL.Set(kendryte.UARTHS_RXCTRL_RXEN)
// Enable interrupts on receive.
uart.Bus.IE.Set(kendryte.UARTHS_IE_RXWM)
intr := interrupt.New(kendryte.IRQ_UARTHS, _UART0.handleInterrupt)
intr.SetPriority(5)
intr.Enable()
}
func (uart *UART) handleInterrupt(interrupt.Interrupt) {
rxdata := uart.Bus.RXDATA.Get()
c := byte(rxdata)
if uint32(c) != rxdata {
// The rxdata has other bits set than just the low 8 bits. This probably
// means that the 'empty' flag is set, which indicates there is no data
// to be read and the byte is garbage. Ignore this byte.
return
}
uart.Receive(c)
}
func (uart *UART) writeByte(c byte) error {
for uart.Bus.TXDATA.Get()&kendryte.UARTHS_TXDATA_FULL != 0 {
}
uart.Bus.TXDATA.Set(uint32(c))
return nil
}
func (uart *UART) flush() {}
type SPI struct {
Bus *kendryte.SPI_Type
}
// SPIConfig is used to store config info for SPI.
type SPIConfig struct {
Frequency uint32
SCK Pin
SDO Pin
SDI 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
// peripheral-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.SDO == 0 && config.SDI == 0 {
config.SCK = SPI0_SCK_PIN
config.SDO = SPI0_SDO_PIN
config.SDI = SPI0_SDI_PIN
}
// Enable APB2 clock.
kendryte.SYSCTL.CLK_EN_CENT.SetBits(kendryte.SYSCTL_CLK_EN_CENT_APB2_CLK_EN)
switch spi.Bus {
case kendryte.SPI0:
// 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)
// Initialize pins.
config.SCK.SetFPIOAFunction(FUNC_SPI0_SCLK)
config.SDO.SetFPIOAFunction(FUNC_SPI0_D0)
config.SDI.SetFPIOAFunction(FUNC_SPI0_D1)
case kendryte.SPI1:
// 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)
// Initialize pins.
config.SCK.SetFPIOAFunction(FUNC_SPI1_SCLK)
config.SDO.SetFPIOAFunction(FUNC_SPI1_D0)
config.SDI.SetFPIOAFunction(FUNC_SPI1_D1)
default:
return errUnsupportedSPIController
}
// Set default frequency.
if config.Frequency == 0 {
config.Frequency = 4000000 // 4MHz
}
baudr := CPUFrequency() / config.Frequency
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
}
// I2C on the K210.
type I2C struct {
Bus kendryte.I2C_Type
}
var (
I2C0 = (*I2C)(unsafe.Pointer(kendryte.I2C0))
I2C1 = (*I2C)(unsafe.Pointer(kendryte.I2C1))
I2C2 = (*I2C)(unsafe.Pointer(kendryte.I2C2))
)
// I2CConfig is used to store config info for I2C.
type I2CConfig struct {
Frequency uint32
SCL Pin
SDA Pin
}
// Configure is intended to setup the I2C interface.
func (i2c *I2C) Configure(config I2CConfig) error {
if config.Frequency == 0 {
config.Frequency = 100 * KHz
}
if config.SDA == 0 && config.SCL == 0 {
config.SDA = I2C0_SDA_PIN
config.SCL = I2C0_SCL_PIN
}
// Enable APB0 clock.
kendryte.SYSCTL.CLK_EN_CENT.SetBits(kendryte.SYSCTL_CLK_EN_CENT_APB0_CLK_EN)
switch &i2c.Bus {
case kendryte.I2C0:
// Initialize I2C0 clock.
kendryte.SYSCTL.CLK_EN_PERI.SetBits(kendryte.SYSCTL_CLK_EN_PERI_I2C0_CLK_EN)
kendryte.SYSCTL.CLK_TH5.ReplaceBits(0x03, kendryte.SYSCTL_CLK_TH5_I2C0_CLK_Msk, kendryte.SYSCTL_CLK_TH5_I2C0_CLK_Pos)
// Initialize pins.
config.SDA.SetFPIOAFunction(FUNC_I2C0_SDA)
config.SCL.SetFPIOAFunction(FUNC_I2C0_SCLK)
case kendryte.I2C1:
// Initialize I2C1 clock.
kendryte.SYSCTL.CLK_EN_PERI.SetBits(kendryte.SYSCTL_CLK_EN_PERI_I2C1_CLK_EN)
kendryte.SYSCTL.CLK_TH5.ReplaceBits(0x03, kendryte.SYSCTL_CLK_TH5_I2C1_CLK_Msk, kendryte.SYSCTL_CLK_TH5_I2C1_CLK_Pos)
// Initialize pins.
config.SDA.SetFPIOAFunction(FUNC_I2C1_SDA)
config.SCL.SetFPIOAFunction(FUNC_I2C1_SCLK)
case kendryte.I2C2:
// Initialize I2C2 clock.
kendryte.SYSCTL.CLK_EN_PERI.SetBits(kendryte.SYSCTL_CLK_EN_PERI_I2C2_CLK_EN)
kendryte.SYSCTL.CLK_TH5.ReplaceBits(0x03, kendryte.SYSCTL_CLK_TH5_I2C2_CLK_Msk, kendryte.SYSCTL_CLK_TH5_I2C2_CLK_Pos)
// Initialize pins.
config.SDA.SetFPIOAFunction(FUNC_I2C2_SDA)
config.SCL.SetFPIOAFunction(FUNC_I2C2_SCLK)
}
i2c.SetBaudRate(config.Frequency)
i2c.Bus.INTR_MASK.Set(0)
i2c.Bus.DMA_CR.Set(0x03)
i2c.Bus.DMA_RDLR.Set(0)
i2c.Bus.DMA_TDLR.Set(0x4)
return nil
}
// SetBaudRate sets the communication speed for I2C.
func (i2c *I2C) SetBaudRate(br uint32) error {
div := CPUFrequency() / br / 16
// Disable controller before setting the prescale register.
i2c.Bus.ENABLE.Set(0)
i2c.Bus.CON.Set(0x63)
// Set prescaler registers.
i2c.Bus.SS_SCL_HCNT.Set(uint32(div))
i2c.Bus.SS_SCL_LCNT.Set(uint32(div))
return nil
}
// Tx does a single I2C transaction at the specified address.
// It clocks out the given address, writes the bytes in w, reads back len(r)
// bytes and stores them in r, and generates a stop condition on the bus.
func (i2c *I2C) Tx(addr uint16, w, r []byte) error {
// Set peripheral address.
i2c.Bus.TAR.Set(uint32(addr))
// Enable controller.
i2c.Bus.ENABLE.Set(1)
if len(w) != 0 {
i2c.Bus.CLR_TX_ABRT.Set(i2c.Bus.CLR_TX_ABRT.Get())
dataLen := uint32(len(w))
di := 0
for dataLen != 0 {
fifoLen := 8 - i2c.Bus.TXFLR.Get()
if dataLen < fifoLen {
fifoLen = dataLen
}
for i := uint32(0); i < fifoLen; i++ {
i2c.Bus.DATA_CMD.Set(uint32(w[di]))
di += 1
}
if i2c.Bus.TX_ABRT_SOURCE.Get() != 0 {
return errI2CTxAbort
}
dataLen -= fifoLen
}
// Wait for transmission to complete.
for i2c.Bus.STATUS.HasBits(kendryte.I2C_STATUS_ACTIVITY) || !i2c.Bus.STATUS.HasBits(kendryte.I2C_STATUS_TFE) {
}
if i2c.Bus.TX_ABRT_SOURCE.Get() != 0 {
return errI2CTxAbort
}
}
if len(r) != 0 {
dataLen := uint32(len(r))
cmdLen := uint32(len(r))
di := 0
for dataLen != 0 || cmdLen != 0 {
fifoLen := i2c.Bus.RXFLR.Get()
if dataLen < fifoLen {
fifoLen = dataLen
}
for i := uint32(0); i < fifoLen; i++ {
r[di] = byte(i2c.Bus.DATA_CMD.Get())
di += 1
}
dataLen -= fifoLen
fifoLen = 8 - i2c.Bus.TXFLR.Get()
if cmdLen < fifoLen {
fifoLen = cmdLen
}
for i := uint32(0); i < fifoLen; i++ {
i2c.Bus.DATA_CMD.Set(0x100)
}
if i2c.Bus.TX_ABRT_SOURCE.Get() != 0 {
return errI2CTxAbort
}
cmdLen -= fifoLen
}
}
return nil
}
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