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https://github.com/tinygo-org/tinygo.git
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stm32: use stm32-rs SVDs which are of much higher quality
This commit changes the number of wait states for the stm32f103 chip to 2 instead of 4. This gets it back in line with the datasheet, but it also has the side effect of breaking I2C. Therefore, another (seemingly unrelated) change is needed: the i2cTimeout constant must be increased to a higher value to adjust to the lower flash wait states - presumably because the lower number of wait states allows the chip to run code faster.
This commit is contained in:
Ayke van Laethem
committed by
Ron Evans
Ron Evans
parent
65caf777dd
commit
154c7c691b
@@ -0,0 +1,657 @@
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// +build stm32,stm32f103
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package machine
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// Peripheral abstraction layer for the stm32.
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import (
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"device/stm32"
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"runtime/interrupt"
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"unsafe"
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)
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func CPUFrequency() uint32 {
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return 72000000
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}
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const (
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PinInput PinMode = 0 // Input mode
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PinOutput10MHz PinMode = 1 // Output mode, max speed 10MHz
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PinOutput2MHz PinMode = 2 // Output mode, max speed 2MHz
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PinOutput50MHz PinMode = 3 // Output mode, max speed 50MHz
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PinOutput PinMode = PinOutput2MHz
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PinInputModeAnalog PinMode = 0 // Input analog mode
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PinInputModeFloating PinMode = 4 // Input floating mode
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PinInputModePullUpDown PinMode = 8 // Input pull up/down mode
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PinInputModeReserved PinMode = 12 // Input mode (reserved)
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PinOutputModeGPPushPull PinMode = 0 // Output mode general purpose push/pull
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PinOutputModeGPOpenDrain PinMode = 4 // Output mode general purpose open drain
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PinOutputModeAltPushPull PinMode = 8 // Output mode alt. purpose push/pull
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PinOutputModeAltOpenDrain PinMode = 12 // Output mode alt. purpose open drain
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)
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// Configure this pin with the given I/O settings.
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// stm32f1xx uses different technique for setting the GPIO pins than the stm32f407
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func (p Pin) Configure(config PinConfig) {
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// Configure the GPIO pin.
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p.enableClock()
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port := p.getPort()
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pin := uint8(p) % 16
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pos := (pin % 8) * 4
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if pin < 8 {
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port.CRL.ReplaceBits(uint32(config.Mode), 0xf, pos)
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} else {
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port.CRH.ReplaceBits(uint32(config.Mode), 0xf, pos)
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}
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}
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func (p Pin) getPort() *stm32.GPIO_Type {
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switch p / 16 {
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case 0:
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return stm32.GPIOA
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case 1:
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return stm32.GPIOB
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case 2:
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return stm32.GPIOC
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case 3:
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return stm32.GPIOD
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case 4:
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return stm32.GPIOE
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case 5:
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return stm32.GPIOF
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case 6:
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return stm32.GPIOG
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default:
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panic("machine: unknown port")
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}
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}
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// enableClock enables the clock for this desired GPIO port.
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func (p Pin) enableClock() {
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switch p / 16 {
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case 0:
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_IOPAEN)
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case 1:
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_IOPBEN)
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case 2:
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_IOPCEN)
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case 3:
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_IOPDEN)
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case 4:
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_IOPEEN)
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case 5:
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_IOPFEN)
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case 6:
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_IOPGEN)
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default:
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panic("machine: unknown port")
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}
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}
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// Enable peripheral clock. Expand to include all the desired peripherals
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func enableAltFuncClock(bus unsafe.Pointer) {
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if bus == unsafe.Pointer(stm32.USART1) {
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_USART1EN)
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} else if bus == unsafe.Pointer(stm32.USART2) {
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART2EN)
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} else if bus == unsafe.Pointer(stm32.I2C1) {
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C1EN)
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} else if bus == unsafe.Pointer(stm32.SPI1) {
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SPI1EN)
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}
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}
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//---------- UART related types and code
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// UART representation
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type UART struct {
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Buffer *RingBuffer
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Bus *stm32.USART_Type
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Interrupt interrupt.Interrupt
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}
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// Configure the TX and RX pins
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func (uart UART) configurePins(config UARTConfig) {
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// pins
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switch config.TX {
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case UART_ALT_TX_PIN:
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// use alternate TX/RX pins via AFIO mapping
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_AFIOEN)
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if uart.Bus == stm32.USART1 {
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stm32.AFIO.MAPR.SetBits(stm32.AFIO_MAPR_USART1_REMAP)
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} else if uart.Bus == stm32.USART2 {
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stm32.AFIO.MAPR.SetBits(stm32.AFIO_MAPR_USART2_REMAP)
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}
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default:
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// use standard TX/RX pins PA9 and PA10
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}
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config.TX.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
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config.RX.Configure(PinConfig{Mode: PinInputModeFloating})
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}
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// Determine the divisor for USARTs to get the given baudrate
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func (uart UART) getBaudRateDivisor(br uint32) uint32 {
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// Note: PCLK2 (from APB2) used for USART1 and PCLK1 for USART2, 3, 4, 5
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var divider uint32
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if uart.Bus == stm32.USART1 {
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// first divide by PCLK2 prescaler (div 1) and then desired baudrate
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divider = CPUFrequency() / br
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} else {
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// first divide by PCLK1 prescaler (div 2) and then desired baudrate
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divider = CPUFrequency() / 2 / br
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}
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return divider
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}
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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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// There are 3 SPI interfaces on the STM32F103xx.
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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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SPI1 = SPI{Bus: stm32.SPI1}
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SPI0 = SPI1
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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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// set frequency dependent on PCLK2 prescaler (div 1)
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switch config.Frequency {
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case 125000:
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// Note: impossible to achieve lower frequency with current PCLK2!
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conf |= stm32.SPI_CR1_BR_Div256
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case 250000:
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conf |= stm32.SPI_CR1_BR_Div256
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case 500000:
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conf |= stm32.SPI_CR1_BR_Div128
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case 1000000:
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conf |= stm32.SPI_CR1_BR_Div64
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case 2000000:
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conf |= stm32.SPI_CR1_BR_Div32
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case 4000000:
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conf |= stm32.SPI_CR1_BR_Div16
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case 8000000:
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conf |= stm32.SPI_CR1_BR_Div8
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default:
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conf |= stm32.SPI_CR1_BR_Div256
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}
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return conf
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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.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
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config.SDO.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltPushPull})
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config.SDI.Configure(PinConfig{Mode: PinInputModeFloating})
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}
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//---------- I2C related types and code
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type I2C struct {
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Bus *stm32.I2C_Type
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}
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// There are 2 I2C interfaces on the STM32F103xx.
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// Since the first interface is named I2C1, both I2C0 and I2C1 refer to I2C1.
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// TODO: implement I2C2.
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var (
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I2C1 = I2C{Bus: stm32.I2C1}
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I2C0 = I2C1
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)
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// I2CConfig is used to store config info for I2C.
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type I2CConfig struct {
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Frequency uint32
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SCL Pin
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SDA Pin
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}
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// Configure is intended to setup the I2C interface.
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func (i2c I2C) Configure(config I2CConfig) {
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// Default I2C bus speed is 100 kHz.
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if config.Frequency == 0 {
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config.Frequency = TWI_FREQ_100KHZ
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}
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// enable clock for I2C
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C1EN)
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// I2C1 pins
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switch config.SDA {
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case PB9:
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config.SCL = PB8
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// use alternate I2C1 pins PB8/PB9 via AFIO mapping
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_AFIOEN)
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stm32.AFIO.MAPR.SetBits(stm32.AFIO_MAPR_I2C1_REMAP)
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default:
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// use default I2C1 pins PB6/PB7
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config.SDA = SDA_PIN
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config.SCL = SCL_PIN
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}
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config.SDA.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltOpenDrain})
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config.SCL.Configure(PinConfig{Mode: PinOutput50MHz + PinOutputModeAltOpenDrain})
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// Disable the selected I2C peripheral to configure
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i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_PE)
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// pclk1 clock speed is main frequency divided by PCLK1 prescaler (div 2)
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pclk1 := CPUFrequency() / 2
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// set freqency range to PCLK1 clock speed in MHz
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// aka setting the value 36 means to use 36 MHz clock
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pclk1Mhz := pclk1 / 1000000
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i2c.Bus.CR2.SetBits(pclk1Mhz)
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switch config.Frequency {
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case TWI_FREQ_100KHZ:
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// Normal mode speed calculation
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ccr := pclk1 / (config.Frequency * 2)
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i2c.Bus.CCR.Set(ccr)
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// duty cycle 2
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i2c.Bus.CCR.ClearBits(stm32.I2C_CCR_DUTY)
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// frequency standard mode
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i2c.Bus.CCR.ClearBits(stm32.I2C_CCR_F_S)
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// Set Maximum Rise Time for standard mode
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i2c.Bus.TRISE.Set(pclk1Mhz)
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case TWI_FREQ_400KHZ:
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// Fast mode speed calculation
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ccr := pclk1 / (config.Frequency * 3)
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i2c.Bus.CCR.Set(ccr)
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// duty cycle 2
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i2c.Bus.CCR.ClearBits(stm32.I2C_CCR_DUTY)
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// frequency fast mode
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i2c.Bus.CCR.SetBits(stm32.I2C_CCR_F_S)
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// Set Maximum Rise Time for fast mode
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i2c.Bus.TRISE.Set(((pclk1Mhz * 300) / 1000))
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}
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// re-enable the selected I2C peripheral
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i2c.Bus.CR1.SetBits(stm32.I2C_CR1_PE)
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}
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// Tx does a single I2C transaction at the specified address.
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// It clocks out the given address, writes the bytes in w, reads back len(r)
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// bytes and stores them in r, and generates a stop condition on the bus.
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func (i2c I2C) Tx(addr uint16, w, r []byte) error {
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var err error
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if len(w) != 0 {
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// start transmission for writing
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err = i2c.signalStart()
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if err != nil {
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return err
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}
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// send address
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err = i2c.sendAddress(uint8(addr), true)
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if err != nil {
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return err
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}
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for _, b := range w {
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err = i2c.WriteByte(b)
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if err != nil {
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return err
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}
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}
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// sending stop here for write
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err = i2c.signalStop()
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if err != nil {
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return err
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}
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}
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if len(r) != 0 {
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// re-start transmission for reading
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err = i2c.signalStart()
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if err != nil {
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return err
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}
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// 1 byte
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switch len(r) {
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case 1:
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// send address
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err = i2c.sendAddress(uint8(addr), false)
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if err != nil {
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return err
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}
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// Disable ACK of received data
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i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_ACK)
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// clear timeout here
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timeout := i2cTimeout
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for !i2c.Bus.SR2.HasBits(stm32.I2C_SR2_MSL | stm32.I2C_SR2_BUSY) {
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timeout--
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if timeout == 0 {
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return errI2CWriteTimeout
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}
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}
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// Generate stop condition
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i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
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timeout = i2cTimeout
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for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_RxNE) {
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timeout--
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if timeout == 0 {
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return errI2CReadTimeout
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}
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}
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// Read and return data byte from I2C data register
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r[0] = byte(i2c.Bus.DR.Get())
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// wait for stop
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return i2c.waitForStop()
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case 2:
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// enable pos
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i2c.Bus.CR1.SetBits(stm32.I2C_CR1_POS)
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// Enable ACK of received data
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i2c.Bus.CR1.SetBits(stm32.I2C_CR1_ACK)
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// send address
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err = i2c.sendAddress(uint8(addr), false)
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if err != nil {
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return err
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}
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// clear address here
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timeout := i2cTimeout
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for !i2c.Bus.SR2.HasBits(stm32.I2C_SR2_MSL | stm32.I2C_SR2_BUSY) {
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timeout--
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if timeout == 0 {
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return errI2CWriteTimeout
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}
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}
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// Disable ACK of received data
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i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_ACK)
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// wait for btf. we need a longer timeout here than normal.
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timeout = 1000
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for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_BTF) {
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timeout--
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if timeout == 0 {
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return errI2CReadTimeout
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}
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}
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// Generate stop condition
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i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
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// read the 2 bytes by reading twice.
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r[0] = byte(i2c.Bus.DR.Get())
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r[1] = byte(i2c.Bus.DR.Get())
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// wait for stop
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err = i2c.waitForStop()
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//disable pos
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i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_POS)
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return err
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case 3:
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// Enable ACK of received data
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i2c.Bus.CR1.SetBits(stm32.I2C_CR1_ACK)
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// send address
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err = i2c.sendAddress(uint8(addr), false)
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if err != nil {
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return err
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}
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// clear address here
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timeout := i2cTimeout
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for !i2c.Bus.SR2.HasBits(stm32.I2C_SR2_MSL | stm32.I2C_SR2_BUSY) {
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timeout--
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if timeout == 0 {
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return errI2CWriteTimeout
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}
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}
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// Enable ACK of received data
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i2c.Bus.CR1.SetBits(stm32.I2C_CR1_ACK)
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// wait for btf. we need a longer timeout here than normal.
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timeout = 1000
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for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_BTF) {
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timeout--
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if timeout == 0 {
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return errI2CReadTimeout
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}
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}
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// Disable ACK of received data
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i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_ACK)
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// read the first byte
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r[0] = byte(i2c.Bus.DR.Get())
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timeout = 1000
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for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_BTF) {
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timeout--
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if timeout == 0 {
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return errI2CReadTimeout
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}
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}
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// Generate stop condition
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i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
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// read the last 2 bytes by reading twice.
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r[1] = byte(i2c.Bus.DR.Get())
|
||||
r[2] = byte(i2c.Bus.DR.Get())
|
||||
|
||||
// wait for stop
|
||||
return i2c.waitForStop()
|
||||
|
||||
default:
|
||||
// more than 3 bytes of data to read
|
||||
|
||||
// send address
|
||||
err = i2c.sendAddress(uint8(addr), false)
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// clear address here
|
||||
timeout := i2cTimeout
|
||||
for !i2c.Bus.SR2.HasBits(stm32.I2C_SR2_MSL | stm32.I2C_SR2_BUSY) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CWriteTimeout
|
||||
}
|
||||
}
|
||||
|
||||
for i := 0; i < len(r)-3; i++ {
|
||||
// Enable ACK of received data
|
||||
i2c.Bus.CR1.SetBits(stm32.I2C_CR1_ACK)
|
||||
|
||||
// wait for btf. we need a longer timeout here than normal.
|
||||
timeout = 1000
|
||||
for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_BTF) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CReadTimeout
|
||||
}
|
||||
}
|
||||
|
||||
// read the next byte
|
||||
r[i] = byte(i2c.Bus.DR.Get())
|
||||
}
|
||||
|
||||
// wait for btf. we need a longer timeout here than normal.
|
||||
timeout = 1000
|
||||
for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_BTF) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CReadTimeout
|
||||
}
|
||||
}
|
||||
|
||||
// Disable ACK of received data
|
||||
i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_ACK)
|
||||
|
||||
// get third from last byte
|
||||
r[len(r)-3] = byte(i2c.Bus.DR.Get())
|
||||
|
||||
// Generate stop condition
|
||||
i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
|
||||
|
||||
// get second from last byte
|
||||
r[len(r)-2] = byte(i2c.Bus.DR.Get())
|
||||
|
||||
timeout = i2cTimeout
|
||||
for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_RxNE) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CReadTimeout
|
||||
}
|
||||
}
|
||||
|
||||
// get last byte
|
||||
r[len(r)-1] = byte(i2c.Bus.DR.Get())
|
||||
|
||||
// wait for stop
|
||||
return i2c.waitForStop()
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
const i2cTimeout = 1000
|
||||
|
||||
// signalStart sends a start signal.
|
||||
func (i2c I2C) signalStart() error {
|
||||
// Wait until I2C is not busy
|
||||
timeout := i2cTimeout
|
||||
for i2c.Bus.SR2.HasBits(stm32.I2C_SR2_BUSY) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CSignalStartTimeout
|
||||
}
|
||||
}
|
||||
|
||||
// clear stop
|
||||
i2c.Bus.CR1.ClearBits(stm32.I2C_CR1_STOP)
|
||||
|
||||
// Generate start condition
|
||||
i2c.Bus.CR1.SetBits(stm32.I2C_CR1_START)
|
||||
|
||||
// Wait for I2C EV5 aka SB flag.
|
||||
timeout = i2cTimeout
|
||||
for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_SB) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CSignalStartTimeout
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// signalStop sends a stop signal and waits for it to succeed.
|
||||
func (i2c I2C) signalStop() error {
|
||||
// Generate stop condition
|
||||
i2c.Bus.CR1.SetBits(stm32.I2C_CR1_STOP)
|
||||
|
||||
// wait for stop
|
||||
return i2c.waitForStop()
|
||||
}
|
||||
|
||||
// waitForStop waits after a stop signal.
|
||||
func (i2c I2C) waitForStop() error {
|
||||
// Wait until I2C is stopped
|
||||
timeout := i2cTimeout
|
||||
for i2c.Bus.SR1.HasBits(stm32.I2C_SR1_STOPF) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CSignalStopTimeout
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// Send address of device we want to talk to
|
||||
func (i2c I2C) sendAddress(address uint8, write bool) error {
|
||||
data := (address << 1)
|
||||
if !write {
|
||||
data |= 1 // set read flag
|
||||
}
|
||||
|
||||
i2c.Bus.DR.Set(uint32(data))
|
||||
|
||||
// Wait for I2C EV6 event.
|
||||
// Destination device acknowledges address
|
||||
timeout := i2cTimeout
|
||||
if write {
|
||||
// EV6 which is ADDR flag.
|
||||
for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_ADDR) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CWriteTimeout
|
||||
}
|
||||
}
|
||||
|
||||
timeout = i2cTimeout
|
||||
for !i2c.Bus.SR2.HasBits(stm32.I2C_SR2_MSL | stm32.I2C_SR2_BUSY | stm32.I2C_SR2_TRA) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CWriteTimeout
|
||||
}
|
||||
}
|
||||
} else {
|
||||
// I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED which is ADDR flag.
|
||||
for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_ADDR) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CWriteTimeout
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
|
||||
// WriteByte writes a single byte to the I2C bus.
|
||||
func (i2c I2C) WriteByte(data byte) error {
|
||||
// Send data byte
|
||||
i2c.Bus.DR.Set(uint32(data))
|
||||
|
||||
// Wait for I2C EV8_2 when data has been physically shifted out and
|
||||
// output on the bus.
|
||||
// I2C_EVENT_MASTER_BYTE_TRANSMITTED is TXE flag.
|
||||
timeout := i2cTimeout
|
||||
for !i2c.Bus.SR1.HasBits(stm32.I2C_SR1_TxE) {
|
||||
timeout--
|
||||
if timeout == 0 {
|
||||
return errI2CWriteTimeout
|
||||
}
|
||||
}
|
||||
|
||||
return nil
|
||||
}
|
||||
Reference in New Issue
Block a user