|
| 1 | +// +build stm32l0 |
| 2 | + |
| 3 | +package machine |
| 4 | + |
| 5 | +// Peripheral abstraction layer for the stm32l0 |
| 6 | + |
| 7 | +import ( |
| 8 | + "device/stm32" |
| 9 | + "runtime/interrupt" |
| 10 | + "unsafe" |
| 11 | +) |
| 12 | + |
| 13 | +func CPUFrequency() uint32 { |
| 14 | + return 32000000 |
| 15 | +} |
| 16 | + |
| 17 | +const ( |
| 18 | + PA0 = portA + 0 |
| 19 | + PA1 = portA + 1 |
| 20 | + PA2 = portA + 2 |
| 21 | + PA3 = portA + 3 |
| 22 | + PA4 = portA + 4 |
| 23 | + PA5 = portA + 5 |
| 24 | + PA6 = portA + 6 |
| 25 | + PA7 = portA + 7 |
| 26 | + PA8 = portA + 8 |
| 27 | + PA9 = portA + 9 |
| 28 | + PA10 = portA + 10 |
| 29 | + PA11 = portA + 11 |
| 30 | + PA12 = portA + 12 |
| 31 | + PA13 = portA + 13 |
| 32 | + PA14 = portA + 14 |
| 33 | + PA15 = portA + 15 |
| 34 | + |
| 35 | + PB0 = portB + 0 |
| 36 | + PB1 = portB + 1 |
| 37 | + PB2 = portB + 2 |
| 38 | + PB3 = portB + 3 |
| 39 | + PB4 = portB + 4 |
| 40 | + PB5 = portB + 5 |
| 41 | + PB6 = portB + 6 |
| 42 | + PB7 = portB + 7 |
| 43 | + PB8 = portB + 8 |
| 44 | + PB9 = portB + 9 |
| 45 | + PB10 = portB + 10 |
| 46 | + PB11 = portB + 11 |
| 47 | + PB12 = portB + 12 |
| 48 | + PB13 = portB + 13 |
| 49 | + PB14 = portB + 14 |
| 50 | + PB15 = portB + 15 |
| 51 | + |
| 52 | + PC0 = portC + 0 |
| 53 | + PC1 = portC + 1 |
| 54 | + PC2 = portC + 2 |
| 55 | + PC3 = portC + 3 |
| 56 | + PC4 = portC + 4 |
| 57 | + PC5 = portC + 5 |
| 58 | + PC6 = portC + 6 |
| 59 | + PC7 = portC + 7 |
| 60 | + PC8 = portC + 8 |
| 61 | + PC9 = portC + 9 |
| 62 | + PC10 = portC + 10 |
| 63 | + PC11 = portC + 11 |
| 64 | + PC12 = portC + 12 |
| 65 | + PC13 = portC + 13 |
| 66 | + PC14 = portC + 14 |
| 67 | + PC15 = portC + 15 |
| 68 | + |
| 69 | + PD0 = portD + 0 |
| 70 | + PD1 = portD + 1 |
| 71 | + PD2 = portD + 2 |
| 72 | + PD3 = portD + 3 |
| 73 | + PD4 = portD + 4 |
| 74 | + PD5 = portD + 5 |
| 75 | + PD6 = portD + 6 |
| 76 | + PD7 = portD + 7 |
| 77 | + PD8 = portD + 8 |
| 78 | + PD9 = portD + 9 |
| 79 | + PD10 = portD + 10 |
| 80 | + PD11 = portD + 11 |
| 81 | + PD12 = portD + 12 |
| 82 | + PD13 = portD + 13 |
| 83 | + PD14 = portD + 14 |
| 84 | + PD15 = portD + 15 |
| 85 | + |
| 86 | + PE0 = portE + 0 |
| 87 | + PE1 = portE + 1 |
| 88 | + PE2 = portE + 2 |
| 89 | + PE3 = portE + 3 |
| 90 | + PE4 = portE + 4 |
| 91 | + PE5 = portE + 5 |
| 92 | + PE6 = portE + 6 |
| 93 | + PE7 = portE + 7 |
| 94 | + PE8 = portE + 8 |
| 95 | + PE9 = portE + 9 |
| 96 | + PE10 = portE + 10 |
| 97 | + PE11 = portE + 11 |
| 98 | + PE12 = portE + 12 |
| 99 | + PE13 = portE + 13 |
| 100 | + PE14 = portE + 14 |
| 101 | + PE15 = portE + 15 |
| 102 | + |
| 103 | + PH0 = portH + 0 |
| 104 | + PH1 = portH + 1 |
| 105 | +) |
| 106 | + |
| 107 | +func (p Pin) getPort() *stm32.GPIO_Type { |
| 108 | + switch p / 16 { |
| 109 | + case 0: |
| 110 | + return stm32.GPIOA |
| 111 | + case 1: |
| 112 | + return stm32.GPIOB |
| 113 | + case 2: |
| 114 | + return stm32.GPIOC |
| 115 | + case 3: |
| 116 | + return stm32.GPIOD |
| 117 | + case 4: |
| 118 | + return stm32.GPIOE |
| 119 | + case 7: |
| 120 | + return stm32.GPIOH |
| 121 | + default: |
| 122 | + panic("machine: unknown port") |
| 123 | + } |
| 124 | +} |
| 125 | + |
| 126 | +// enableClock enables the clock for this desired GPIO port. |
| 127 | +func (p Pin) enableClock() { |
| 128 | + switch p / 16 { |
| 129 | + case 0: |
| 130 | + stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPAEN) |
| 131 | + case 1: |
| 132 | + stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPBEN) |
| 133 | + case 2: |
| 134 | + stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPCEN) |
| 135 | + case 3: |
| 136 | + stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPDEN) |
| 137 | + case 4: |
| 138 | + stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPEEN) |
| 139 | + case 7: |
| 140 | + stm32.RCC.IOPENR.SetBits(stm32.RCC_IOPENR_IOPHEN) |
| 141 | + default: |
| 142 | + panic("machine: unknown port") |
| 143 | + } |
| 144 | +} |
| 145 | + |
| 146 | +// Enable peripheral clock |
| 147 | +func enableAltFuncClock(bus unsafe.Pointer) { |
| 148 | + switch bus { |
| 149 | + case unsafe.Pointer(stm32.DAC): // DAC interface clock enable |
| 150 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_DACEN) |
| 151 | + case unsafe.Pointer(stm32.PWR): // Power interface clock enable |
| 152 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_PWREN) |
| 153 | + case unsafe.Pointer(stm32.I2C3): // I2C3 clock enable |
| 154 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C3EN) |
| 155 | + case unsafe.Pointer(stm32.I2C2): // I2C2 clock enable |
| 156 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C2EN) |
| 157 | + case unsafe.Pointer(stm32.I2C1): // I2C1 clock enable |
| 158 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_I2C1EN) |
| 159 | + case unsafe.Pointer(stm32.USART5): // UART5 clock enable |
| 160 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART5EN) |
| 161 | + case unsafe.Pointer(stm32.USART4): // UART4 clock enable |
| 162 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART4EN) |
| 163 | + case unsafe.Pointer(stm32.USART2): // USART2 clock enable |
| 164 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_USART2EN) |
| 165 | + case unsafe.Pointer(stm32.SPI2): // SPI2 clock enable |
| 166 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_SPI2EN) |
| 167 | + case unsafe.Pointer(stm32.LPUSART1): // LPUSART1 clock enable |
| 168 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_LPUART1EN) |
| 169 | + case unsafe.Pointer(stm32.WWDG): // Window watchdog clock enable |
| 170 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_WWDGEN) |
| 171 | + case unsafe.Pointer(stm32.TIM7): // TIM7 clock enable |
| 172 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM7EN) |
| 173 | + case unsafe.Pointer(stm32.TIM6): // TIM6 clock enable |
| 174 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM6EN) |
| 175 | + case unsafe.Pointer(stm32.TIM3): // TIM3 clock enable |
| 176 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM3EN) |
| 177 | + case unsafe.Pointer(stm32.TIM2): // TIM2 clock enable |
| 178 | + stm32.RCC.APB1ENR.SetBits(stm32.RCC_APB1ENR_TIM2EN) |
| 179 | + case unsafe.Pointer(stm32.SYSCFG_COMP): // System configuration controller clock enable |
| 180 | + stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SYSCFGEN) |
| 181 | + case unsafe.Pointer(stm32.SPI1): // SPI1 clock enable |
| 182 | + stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_SPI1EN) |
| 183 | + case unsafe.Pointer(stm32.ADC): // ADC clock enable |
| 184 | + stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_ADCEN) |
| 185 | + case unsafe.Pointer(stm32.USART1): // USART1 clock enable |
| 186 | + stm32.RCC.APB2ENR.SetBits(stm32.RCC_APB2ENR_USART1EN) |
| 187 | + } |
| 188 | +} |
| 189 | + |
| 190 | +//---------- UART related types and code |
| 191 | + |
| 192 | +// UART representation |
| 193 | +type UART struct { |
| 194 | + Buffer *RingBuffer |
| 195 | + Bus *stm32.USART_Type |
| 196 | + Interrupt interrupt.Interrupt |
| 197 | + AltFuncSelector stm32.AltFunc |
| 198 | +} |
| 199 | + |
| 200 | +// Configure the UART. |
| 201 | +func (uart UART) configurePins(config UARTConfig) { |
| 202 | + // enable the alternate functions on the TX and RX pins |
| 203 | + config.TX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTTX}, uart.AltFuncSelector) |
| 204 | + config.RX.ConfigureAltFunc(PinConfig{Mode: PinModeUARTRX}, uart.AltFuncSelector) |
| 205 | +} |
| 206 | + |
| 207 | +// UART baudrate calc based on the bus and clockspeed |
| 208 | +func (uart UART) getBaudRateDivisor(baudRate uint32) uint32 { |
| 209 | + var clock, rate uint32 |
| 210 | + switch uart.Bus { |
| 211 | + case stm32.LPUSART1: |
| 212 | + clock = CPUFrequency() / 2 // APB1 Frequency |
| 213 | + rate = uint32((256 * clock) / baudRate) |
| 214 | + case stm32.USART1: |
| 215 | + clock = CPUFrequency() / 2 // APB2 Frequency |
| 216 | + rate = uint32(clock / baudRate) |
| 217 | + case stm32.USART2: |
| 218 | + clock = CPUFrequency() / 2 // APB1 Frequency |
| 219 | + rate = uint32(clock / baudRate) |
| 220 | + } |
| 221 | + |
| 222 | + return rate |
| 223 | +} |
| 224 | + |
| 225 | +//---------- SPI related types and code |
| 226 | + |
| 227 | +// SPI on the STM32Fxxx using MODER / alternate function pins |
| 228 | +type SPI struct { |
| 229 | + Bus *stm32.SPI_Type |
| 230 | + AltFuncSelector stm32.AltFunc |
| 231 | +} |
| 232 | + |
| 233 | +// Set baud rate for SPI |
| 234 | +func (spi SPI) getBaudRate(config SPIConfig) uint32 { |
| 235 | + var conf uint32 |
| 236 | + |
| 237 | + localFrequency := config.Frequency |
| 238 | + |
| 239 | + // Default |
| 240 | + if config.Frequency == 0 { |
| 241 | + config.Frequency = 4e6 |
| 242 | + } |
| 243 | + |
| 244 | + if spi.Bus != stm32.SPI1 { |
| 245 | + // Assume it's SPI2 or SPI3 on APB1 at 1/2 the clock frequency of APB2, so |
| 246 | + // we want to pretend to request 2x the baudrate asked for |
| 247 | + localFrequency = localFrequency * 2 |
| 248 | + } |
| 249 | + |
| 250 | + // set frequency dependent on PCLK prescaler. Since these are rather weird |
| 251 | + // speeds due to the CPU freqency, pick a range up to that frquency for |
| 252 | + // clients to use more human-understandable numbers, e.g. nearest 100KHz |
| 253 | + |
| 254 | + // These are based on APB2 clock frquency (84MHz on the discovery board) |
| 255 | + // TODO: also include the MCU/APB clock setting in the equation |
| 256 | + switch { |
| 257 | + case localFrequency < 328125: |
| 258 | + conf = stm32.SPI_PCLK_256 |
| 259 | + case localFrequency < 656250: |
| 260 | + conf = stm32.SPI_PCLK_128 |
| 261 | + case localFrequency < 1312500: |
| 262 | + conf = stm32.SPI_PCLK_64 |
| 263 | + case localFrequency < 2625000: |
| 264 | + conf = stm32.SPI_PCLK_32 |
| 265 | + case localFrequency < 5250000: |
| 266 | + conf = stm32.SPI_PCLK_16 |
| 267 | + case localFrequency < 10500000: |
| 268 | + conf = stm32.SPI_PCLK_8 |
| 269 | + // NOTE: many SPI components won't operate reliably (or at all) above 10MHz |
| 270 | + // Check the datasheet of the part |
| 271 | + case localFrequency < 21000000: |
| 272 | + conf = stm32.SPI_PCLK_4 |
| 273 | + case localFrequency < 42000000: |
| 274 | + conf = stm32.SPI_PCLK_2 |
| 275 | + default: |
| 276 | + // None of the specific baudrates were selected; choose the lowest speed |
| 277 | + conf = stm32.SPI_PCLK_256 |
| 278 | + } |
| 279 | + |
| 280 | + return conf << stm32.SPI_CR1_BR_Pos |
| 281 | +} |
| 282 | + |
| 283 | +// Configure SPI pins for input output and clock |
| 284 | +func (spi SPI) configurePins(config SPIConfig) { |
| 285 | + config.SCK.ConfigureAltFunc(PinConfig{Mode: PinModeSPICLK}, spi.AltFuncSelector) |
| 286 | + config.SDO.ConfigureAltFunc(PinConfig{Mode: PinModeSPISDO}, spi.AltFuncSelector) |
| 287 | + config.SDI.ConfigureAltFunc(PinConfig{Mode: PinModeSPISDI}, spi.AltFuncSelector) |
| 288 | +} |
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