stm32 add SPI for stm32f4
Этот коммит содержится в:
GeoffThomas
Ron Evans
родитель
ac73430502
коммит
b4dddfe439
6 изменённых файлов: 217 добавлений и 93 удалений
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@ -43,3 +43,15 @@ const (
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GPIOPUPDRPullUp = 1
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GPIOPUPDRPullDown = 2
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)
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// SPI prescaler values fPCLK / X
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const (
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SPI_PCLK_2 = 0
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SPI_PCLK_4 = 1
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SPI_PCLK_8 = 2
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SPI_PCLK_16 = 3
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SPI_PCLK_32 = 4
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SPI_PCLK_64 = 5
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SPI_PCLK_128 = 6
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SPI_PCLK_256 = 7
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)
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@ -129,3 +129,30 @@ var (
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func init() {
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UART0.Interrupt = interrupt.New(stm32.IRQ_USART2, UART0.handleInterrupt)
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}
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// SPI pins
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const (
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SPI1_SCK_PIN = PA5
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SPI1_MISO_PIN = PA6
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SPI1_MOSI_PIN = PA7
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SPI0_SCK_PIN = SPI1_SCK_PIN
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SPI0_MISO_PIN = SPI1_MISO_PIN
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SPI0_MOSI_PIN = SPI1_MOSI_PIN
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)
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// MEMs accelerometer
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const (
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MEMS_ACCEL_CS = PE3
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MEMS_ACCEL_INT1 = PE0
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MEMS_ACCEL_INT2 = PE1
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)
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// Since the first interface is named SPI1, both SPI0 and SPI1 refer to SPI1.
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// TODO: implement SPI2 and SPI3.
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var (
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SPI0 = SPI{
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Bus: stm32.SPI1,
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AltFuncSelector: stm32.AF5_SPI1_SPI2,
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}
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SPI1 = &SPI0
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)
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99
src/machine/machine_stm32_spi.go
Обычный файл
99
src/machine/machine_stm32_spi.go
Обычный файл
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@ -0,0 +1,99 @@
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// +build stm32
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package machine
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// Peripheral abstraction layer for SPI on the stm32 family
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import (
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"device/stm32"
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"unsafe"
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)
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// SPIConfig is used to store config info for SPI.
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type SPIConfig struct {
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Frequency uint32
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SCK Pin
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MOSI Pin
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MISO Pin
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LSBFirst bool
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Mode uint8
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}
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// Configure is intended to setup the STM32 SPI1 interface.
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// Features still TODO:
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// - support SPI2 and SPI3
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// - allow setting data size to 16 bits?
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// - allow setting direction in HW for additional optimization?
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// - hardware SS pin?
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func (spi SPI) Configure(config SPIConfig) {
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// enable clock for SPI
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enableAltFuncClock(unsafe.Pointer(spi.Bus))
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// Get SPI baud rate based on the bus speed it's attached to
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var conf uint32 = spi.getBaudRate(config)
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// set bit transfer order
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if config.LSBFirst {
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conf |= stm32.SPI_CR1_LSBFIRST
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}
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// set polarity and phase on the SPI interface
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switch config.Mode {
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case Mode0:
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conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
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case Mode1:
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conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf |= (1 << stm32.SPI_CR1_CPHA_Pos)
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case Mode2:
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conf |= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
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case Mode3:
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conf |= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf |= (1 << stm32.SPI_CR1_CPHA_Pos)
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default: // to mode 0
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conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
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}
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// set to SPI master
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conf |= stm32.SPI_CR1_MSTR
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// disable MCU acting as SPI slave
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conf |= stm32.SPI_CR1_SSM | stm32.SPI_CR1_SSI
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// now set the configuration
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spi.Bus.CR1.Set(conf)
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// init pins
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if config.SCK == 0 && config.MOSI == 0 && config.MISO == 0 {
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config.SCK = SPI0_SCK_PIN
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config.MOSI = SPI0_MOSI_PIN
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config.MISO = SPI0_MISO_PIN
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}
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spi.configurePins(config)
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// enable SPI interface
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spi.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
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}
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// Transfer writes/reads a single byte using the SPI interface.
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func (spi SPI) Transfer(w byte) (byte, error) {
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// Write data to be transmitted to the SPI data register
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spi.Bus.DR.Set(uint32(w))
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// Wait until transmit complete
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for !spi.Bus.SR.HasBits(stm32.SPI_SR_TXE) {
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}
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// Wait until receive complete
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for !spi.Bus.SR.HasBits(stm32.SPI_SR_RXNE) {
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}
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// Wait until SPI is not busy
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for spi.Bus.SR.HasBits(stm32.SPI_SR_BSY) {
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}
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// Return received data from SPI data register
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return byte(spi.Bus.DR.Get()), nil
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}
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@ -148,7 +148,8 @@ func (uart UART) getBaudRateDivisor(br uint32) uint32 {
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return divider
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}
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// SPI on the STM32.
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//---------- SPI related types and code
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type SPI struct {
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Bus *stm32.SPI_Type
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}
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@ -161,26 +162,8 @@ var (
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SPI0 = SPI1
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)
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// SPIConfig is used to store config info for SPI.
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type SPIConfig struct {
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Frequency uint32
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SCK Pin
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MOSI Pin
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MISO Pin
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LSBFirst bool
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Mode uint8
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}
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// Configure is intended to setup the STM32 SPI1 interface.
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// Features still TODO:
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// - support SPI2 and SPI3
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// - allow setting data size to 16 bits?
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// - allow setting direction in HW for additional optimization?
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// - hardware SS pin?
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func (spi SPI) Configure(config SPIConfig) {
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// enable clock for SPI
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SPI1EN)
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// Set baud rate for SPI
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func (spi SPI) getBaudRate(config SPIConfig) uint32 {
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var conf uint32
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// set frequency dependent on PCLK2 prescaler (div 1)
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@ -203,82 +186,18 @@ func (spi SPI) Configure(config SPIConfig) {
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default:
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conf |= stm32.SPI_BaudRatePrescaler_256
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}
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// set bit transfer order
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if config.LSBFirst {
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conf |= stm32.SPI_FirstBit_LSB
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}
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// set mode
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switch config.Mode {
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case 0:
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conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
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case 1:
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conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf |= (1 << stm32.SPI_CR1_CPHA_Pos)
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case 2:
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conf |= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
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case 3:
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conf |= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf |= (1 << stm32.SPI_CR1_CPHA_Pos)
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default: // to mode 0
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conf &^= (1 << stm32.SPI_CR1_CPOL_Pos)
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conf &^= (1 << stm32.SPI_CR1_CPHA_Pos)
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}
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// set to SPI master
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conf |= stm32.SPI_Mode_Master
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// now set the configuration
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spi.Bus.CR1.Set(conf)
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// init pins
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spi.setPins(config.SCK, config.MOSI, config.MISO)
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// enable SPI interface
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spi.Bus.CR1.SetBits(stm32.SPI_CR1_SPE)
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return conf
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}
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// Transfer writes/reads a single byte using the SPI interface.
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func (spi SPI) Transfer(w byte) (byte, error) {
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// Write data to be transmitted to the SPI data register
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spi.Bus.DR.Set(uint32(w))
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// Wait until transmit complete
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for !spi.Bus.SR.HasBits(stm32.SPI_SR_TXE) {
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}
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// Wait until receive complete
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for !spi.Bus.SR.HasBits(stm32.SPI_SR_RXNE) {
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}
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// Wait until SPI is not busy
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for spi.Bus.SR.HasBits(stm32.SPI_SR_BSY) {
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}
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// Return received data from SPI data register
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return byte(spi.Bus.DR.Get()), nil
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// Configure SPI pins for input output and clock
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func (spi SPI) configurePins(config SPIConfig) {
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config.SCK.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
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config.MOSI.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
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config.MISO.Configure(PinConfig{Mode: PinInputModeFloating})
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}
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func (spi SPI) setPins(sck, mosi, miso Pin) {
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if sck == 0 {
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sck = SPI0_SCK_PIN
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}
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if mosi == 0 {
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mosi = SPI0_MOSI_PIN
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}
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if miso == 0 {
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miso = SPI0_MISO_PIN
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}
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//---------- I2C related types and code
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sck.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
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mosi.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
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miso.Configure(PinConfig{Mode: PinInputModeFloating})
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}
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// I2C on the STM32F103xx.
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type I2C struct {
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Bus *stm32.I2C_Type
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}
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@ -108,3 +108,62 @@ func (uart UART) getBaudRateDivisor(baudRate uint32) uint32 {
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}
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return clock / baudRate
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}
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//---------- SPI related types and code
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// SPI on the STM32Fxxx using MODER / alternate function pins
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type SPI struct {
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Bus *stm32.SPI_Type
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AltFuncSelector stm32.AltFunc
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}
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// Set baud rate for SPI
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func (spi SPI) getBaudRate(config SPIConfig) uint32 {
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var conf uint32
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localFrequency := config.Frequency
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if spi.Bus != stm32.SPI1 {
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// Assume it's SPI2 or SPI3 on APB1 at 1/2 the clock frequency of APB2, so
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// we want to pretend to request 2x the baudrate asked for
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localFrequency = localFrequency * 2
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}
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// set frequency dependent on PCLK prescaler. Since these are rather weird
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// speeds due to the CPU freqency, pick a range up to that frquency for
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// clients to use more human-understandable numbers, e.g. nearest 100KHz
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// These are based on APB2 clock frquency (84MHz on the discovery board)
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// TODO: also include the MCU/APB clock setting in the equation
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switch true {
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case localFrequency < 328125:
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conf = stm32.SPI_PCLK_256
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case localFrequency < 656250:
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conf = stm32.SPI_PCLK_128
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case localFrequency < 1312500:
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conf = stm32.SPI_PCLK_64
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case localFrequency < 2625000:
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conf = stm32.SPI_PCLK_32
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case localFrequency < 5250000:
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conf = stm32.SPI_PCLK_16
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case localFrequency < 10500000:
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conf = stm32.SPI_PCLK_8
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// NOTE: many SPI components won't operate reliably (or at all) above 10MHz
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// Check the datasheet of the part
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case localFrequency < 21000000:
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conf = stm32.SPI_PCLK_4
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case localFrequency < 42000000:
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conf = stm32.SPI_PCLK_2
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default:
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// None of the specific baudrates were selected; choose the lowest speed
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conf = stm32.SPI_PCLK_256
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}
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return conf << stm32.SPI_CR1_BR_Pos
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}
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// Configure SPI pins for input output and clock
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func (spi SPI) configurePins(config SPIConfig) {
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config.SCK.ConfigureAltFunc(PinConfig{Mode: PinModeSPICLK}, spi.AltFuncSelector)
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config.MOSI.ConfigureAltFunc(PinConfig{Mode: PinModeSPIMOSI}, spi.AltFuncSelector)
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config.MISO.ConfigureAltFunc(PinConfig{Mode: PinModeSPIMISO}, spi.AltFuncSelector)
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}
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@ -1,9 +1,17 @@
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// +build !baremetal sam stm32,!stm32f407 fe310
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// +build !baremetal sam stm32 fe310
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package machine
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import "errors"
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// SPI phase and polarity configs CPOL and CPHA
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const (
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Mode0 = 0
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Mode1 = 1
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Mode2 = 2
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Mode3 = 3
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)
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var (
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ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
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)
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