mirror of
https://github.com/tinygo-org/tinygo.git
synced 2026-08-07 12:33:42 +00:00
Kenneth Bell
288 lines
7.7 KiB
Go
288 lines
7.7 KiB
Go
// +build stm32l0
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package machine
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// Peripheral abstraction layer for the stm32l0
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import (
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"device/stm32"
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"unsafe"
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)
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func CPUFrequency() uint32 {
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return 32000000
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}
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const (
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PA0 = portA + 0
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PA1 = portA + 1
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PA2 = portA + 2
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PA3 = portA + 3
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PA4 = portA + 4
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PA5 = portA + 5
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PA6 = portA + 6
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PA7 = portA + 7
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PA8 = portA + 8
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PA9 = portA + 9
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PA10 = portA + 10
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PA11 = portA + 11
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PA12 = portA + 12
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PA13 = portA + 13
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PA14 = portA + 14
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PA15 = portA + 15
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PB0 = portB + 0
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PB1 = portB + 1
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PB2 = portB + 2
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PB3 = portB + 3
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PB4 = portB + 4
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PB5 = portB + 5
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PB6 = portB + 6
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PB7 = portB + 7
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PB8 = portB + 8
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PB9 = portB + 9
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PB10 = portB + 10
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PB11 = portB + 11
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PB12 = portB + 12
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PB13 = portB + 13
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PB14 = portB + 14
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PB15 = portB + 15
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PC0 = portC + 0
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PC1 = portC + 1
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PC2 = portC + 2
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PC3 = portC + 3
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PC4 = portC + 4
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PC5 = portC + 5
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PC6 = portC + 6
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PC7 = portC + 7
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PC8 = portC + 8
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PC9 = portC + 9
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PC10 = portC + 10
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PC11 = portC + 11
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PC12 = portC + 12
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PC13 = portC + 13
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PC14 = portC + 14
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PC15 = portC + 15
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PD0 = portD + 0
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PD1 = portD + 1
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PD2 = portD + 2
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PD3 = portD + 3
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PD4 = portD + 4
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PD5 = portD + 5
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PD6 = portD + 6
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PD7 = portD + 7
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PD8 = portD + 8
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PD9 = portD + 9
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PD10 = portD + 10
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PD11 = portD + 11
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PD12 = portD + 12
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PD13 = portD + 13
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PD14 = portD + 14
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PD15 = portD + 15
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PE0 = portE + 0
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PE1 = portE + 1
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PE2 = portE + 2
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PE3 = portE + 3
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PE4 = portE + 4
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PE5 = portE + 5
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PE6 = portE + 6
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PE7 = portE + 7
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PE8 = portE + 8
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PE9 = portE + 9
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PE10 = portE + 10
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PE11 = portE + 11
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PE12 = portE + 12
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PE13 = portE + 13
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PE14 = portE + 14
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PE15 = portE + 15
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PH0 = portH + 0
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PH1 = portH + 1
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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 7:
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return stm32.GPIOH
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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.IOPENR.SetBits(stm32.RCC_IOPENR_IOPAEN)
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case 1:
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stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPBEN)
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case 2:
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stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPCEN)
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case 3:
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stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPDEN)
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case 4:
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stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPEEN)
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case 7:
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stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPHEN)
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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
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func enableAltFuncClock(bus unsafe.Pointer) {
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switch bus {
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case unsafe.Pointer(stm32.DAC): // DAC interface clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_DACEN)
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case unsafe.Pointer(stm32.PWR): // Power interface clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_PWREN)
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case unsafe.Pointer(stm32.I2C3): // I2C3 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C3EN)
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case unsafe.Pointer(stm32.I2C2): // I2C2 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C2EN)
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case unsafe.Pointer(stm32.I2C1): // I2C1 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C1EN)
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case unsafe.Pointer(stm32.USART5): // UART5 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART5EN)
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case unsafe.Pointer(stm32.USART4): // UART4 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART4EN)
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case unsafe.Pointer(stm32.USART2): // USART2 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART2EN)
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case unsafe.Pointer(stm32.SPI2): // SPI2 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_SPI2EN)
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case unsafe.Pointer(stm32.LPUART1): // LPUART1 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_LPUART1EN)
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case unsafe.Pointer(stm32.WWDG): // Window watchdog clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_WWDGEN)
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case unsafe.Pointer(stm32.TIM7): // TIM7 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM7EN)
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case unsafe.Pointer(stm32.TIM6): // TIM6 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM6EN)
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case unsafe.Pointer(stm32.TIM3): // TIM3 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM3EN)
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case unsafe.Pointer(stm32.TIM2): // TIM2 clock enable
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stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM2EN)
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case unsafe.Pointer(stm32.SYSCFG): // System configuration controller clock enable
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SYSCFGEN)
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case unsafe.Pointer(stm32.SPI1): // SPI1 clock enable
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SPI1EN)
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case unsafe.Pointer(stm32.ADC): // ADC clock enable
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_ADCEN)
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case unsafe.Pointer(stm32.USART1): // USART1 clock enable
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stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_USART1EN)
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}
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}
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//---------- UART related types and code
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// Configure the UART.
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func (uart UART) configurePins(config UARTConfig) {
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// enable the alternate functions on the TX and RX pins
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config.TX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTTX}, uart.TxAltFuncSelector)
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config.RX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTRX}, uart.RxAltFuncSelector)
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}
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// UART baudrate calc based on the bus and clockspeed
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func (uart UART) getBaudRateDivisor(baudRate uint32) uint32 {
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var clock, rate uint32
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switch uart.Bus {
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case stm32.LPUART1:
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clock = CPUFrequency() / 2 // APB1 Frequency
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rate = uint32((256 * clock) / baudRate)
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case stm32.USART1:
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clock = CPUFrequency() / 2 // APB2 Frequency
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rate = uint32(clock / baudRate)
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case stm32.USART2:
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clock = CPUFrequency() / 2 // APB1 Frequency
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rate = uint32(clock / baudRate)
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}
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return rate
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}
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// Register names vary by ST processor, these are for STM L0 family
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func (uart *UART) setRegisters() {
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uart.rxReg = &uart.Bus.RDR
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uart.txReg = &uart.Bus.TDR
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uart.statusReg = &uart.Bus.ISR
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uart.txEmptyFlag = stm32.USART_ISR_TXE
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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 uint8
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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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// Default
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if config.Frequency == 0 {
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config.Frequency = 4e6
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}
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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 {
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case localFrequency < 328125:
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conf = stm32.SPI_CR1_BR_Div256
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case localFrequency < 656250:
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conf = stm32.SPI_CR1_BR_Div128
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case localFrequency < 1312500:
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conf = stm32.SPI_CR1_BR_Div64
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case localFrequency < 2625000:
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conf = stm32.SPI_CR1_BR_Div32
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case localFrequency < 5250000:
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conf = stm32.SPI_CR1_BR_Div16
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case localFrequency < 10500000:
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conf = stm32.SPI_CR1_BR_Div8
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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_CR1_BR_Div4
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case localFrequency < 42000000:
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conf = stm32.SPI_CR1_BR_Div2
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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_CR1_BR_Div256
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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.SDO.ConfigureAltFunc(PinConfig{Mode: PinModeSPISDO}, spi.AltFuncSelector)
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config.SDI.ConfigureAltFunc(PinConfig{Mode: PinModeSPISDI}, spi.AltFuncSelector)
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}
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