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Diffstat (limited to 'hw/bsp/stm32f4discovery/src/system_stm32f4xx.c')
| -rw-r--r-- | hw/bsp/stm32f4discovery/src/system_stm32f4xx.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/hw/bsp/stm32f4discovery/src/system_stm32f4xx.c b/hw/bsp/stm32f4discovery/src/system_stm32f4xx.c new file mode 100644 index 00000000..34036cac --- /dev/null +++ b/hw/bsp/stm32f4discovery/src/system_stm32f4xx.c @@ -0,0 +1,351 @@ +/** + ****************************************************************************** + * @file system_stm32f4xx.c + * @author MCD Application Team + * @version V1.3.0 + * @date 01-July-2015 + * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File. + * + * This file provides two functions and one global variable to be called from + * user application: + * - SystemInit(): This function is called at startup just after reset and + * before branch to main program. This call is made inside + * the "startup_stm32f4xx.s" file. + * + * - SystemCoreClock variable: Contains the core clock (HCLK), it can be used + * by the user application to setup the SysTick + * timer or configure other parameters. + * + * - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must + * be called whenever the core clock is changed + * during program execution. + * + * + ****************************************************************************** + * @attention + * + * <h2><center>© COPYRIGHT 2015 STMicroelectronics</center></h2> + * + * Redistribution and use in source and binary forms, with or without modification, + * are permitted provided that the following conditions are met: + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. Neither the name of STMicroelectronics nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************** + */ + +/** @addtogroup CMSIS + * @{ + */ + +/** @addtogroup stm32f4xx_system + * @{ + */ + +/** @addtogroup STM32F4xx_System_Private_Includes + * @{ + */ + +#include "mcu/stm32f4xx.h" +#include "bsp/cmsis_nvic.h" + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_TypesDefinitions + * @{ + */ + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_Defines + * @{ + */ + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_Macros + * @{ + */ + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_Variables + * @{ + */ + /* This variable is updated in three ways: + 1) by calling CMSIS function SystemCoreClockUpdate() + 2) by calling HAL API function HAL_RCC_GetHCLKFreq() + 3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency + Note: If you use this function to configure the system clock; then there + is no need to call the 2 first functions listed above, since SystemCoreClock + variable is updated automatically. + */ +uint32_t SystemCoreClock = 168000000; + +const uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9}; + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_FunctionPrototypes + * @{ + */ + +static void SystemClock_Config(void); + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_Functions + * @{ + */ + +/** + * @brief Setup the microcontroller system + * Initialize the FPU setting, vector table location and External memory + * configuration. + * @param None + * @retval None + */ +void SystemInit(void) +{ + /* FPU settings ------------------------------------------------------------*/ + #if (__FPU_PRESENT == 1) && (__FPU_USED == 1) + SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); /* set CP10 and CP11 Full Access */ + #endif + /* Reset the RCC clock configuration to the default reset state ------------*/ + /* Set HSION bit */ + RCC->CR |= (uint32_t)0x00000001; + + /* Reset CFGR register */ + RCC->CFGR = 0x00000000; + + /* Reset HSEON, CSSON and PLLON bits */ + RCC->CR &= (uint32_t)0xFEF6FFFF; + + /* Reset PLLCFGR register */ + RCC->PLLCFGR = 0x24003010; + + /* Reset HSEBYP bit */ + RCC->CR &= (uint32_t)0xFFFBFFFF; + + /* Disable all interrupts */ + RCC->CIR = 0x00000000; + + /* Configure System Clock */ + SystemClock_Config(); + + /* Relocate the vector table */ + NVIC_Relocate(); +} + +/** + * @brief Update SystemCoreClock variable according to Clock Register Values. + * The SystemCoreClock variable contains the core clock (HCLK), it can + * be used by the user application to setup the SysTick timer or configure + * other parameters. + * + * @note Each time the core clock (HCLK) changes, this function must be called + * to update SystemCoreClock variable value. Otherwise, any configuration + * based on this variable will be incorrect. + * + * @note - The system frequency computed by this function is not the real + * frequency in the chip. It is calculated based on the predefined + * constant and the selected clock source: + * + * - If SYSCLK source is HSI, SystemCoreClock will contain the HSI_VALUE(*) + * + * - If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(**) + * + * - If SYSCLK source is PLL, SystemCoreClock will contain the HSE_VALUE(**) + * or HSI_VALUE(*) multiplied/divided by the PLL factors. + * + * (*) HSI_VALUE is a constant defined in stm32f4xx_hal_conf.h file (default value + * 16 MHz) but the real value may vary depending on the variations + * in voltage and temperature. + * + * (**) HSE_VALUE is a constant defined in stm32f4xx_hal_conf.h file (its value + * depends on the application requirements), user has to ensure that HSE_VALUE + * is same as the real frequency of the crystal used. Otherwise, this function + * may have wrong result. + * + * - The result of this function could be not correct when using fractional + * value for HSE crystal. + * + * @param None + * @retval None + */ +void SystemCoreClockUpdate(void) +{ + uint32_t tmp = 0, pllvco = 0, pllp = 2, pllsource = 0, pllm = 2; + + /* Get SYSCLK source -------------------------------------------------------*/ + tmp = RCC->CFGR & RCC_CFGR_SWS; + + switch (tmp) + { + case 0x00: /* HSI used as system clock source */ + SystemCoreClock = HSI_VALUE; + break; + case 0x04: /* HSE used as system clock source */ + SystemCoreClock = HSE_VALUE; + break; + case 0x08: /* PLL used as system clock source */ + + /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N + SYSCLK = PLL_VCO / PLL_P + */ + pllsource = (RCC->PLLCFGR & RCC_PLLCFGR_PLLSRC) >> 22; + pllm = RCC->PLLCFGR & RCC_PLLCFGR_PLLM; + + if (pllsource != 0) + { + /* HSE used as PLL clock source */ + pllvco = (HSE_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6); + } + else + { + /* HSI used as PLL clock source */ + pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6); + } + + pllp = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLP) >>16) + 1 ) *2; + SystemCoreClock = pllvco/pllp; + break; + default: + SystemCoreClock = HSI_VALUE; + break; + } + /* Compute HCLK frequency --------------------------------------------------*/ + /* Get HCLK prescaler */ + tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)]; + /* HCLK frequency */ + SystemCoreClock >>= tmp; +} + +/** + * @brief System Clock Configuration + * The system Clock is configured as follow : + * System Clock source = PLL (HSE) + * SYSCLK(Hz) = 168000000 + * HCLK(Hz) = 168000000 + * AHB Prescaler = 1 + * APB1 Prescaler = 4 + * APB2 Prescaler = 2 + * HSE Frequency(Hz) = 12000000 + * PLL_M = 12 + * PLL_N = 336 + * PLL_P = 2 + * PLL_Q = 7 + * VDD(V) = 3.3 + * Main regulator output voltage = Scale1 mode + * Flash Latency(WS) = 5 + * @param None + * @retval None + */ +static void SystemClock_Config(void) +{ + /* Configure Flash prefetch, Instruction cache, Data cache */ +#if (INSTRUCTION_CACHE_ENABLE != 0) + __HAL_FLASH_INSTRUCTION_CACHE_ENABLE(); +#endif /* INSTRUCTION_CACHE_ENABLE */ + +#if (DATA_CACHE_ENABLE != 0) + __HAL_FLASH_DATA_CACHE_ENABLE(); +#endif /* DATA_CACHE_ENABLE */ + +#if (PREFETCH_ENABLE != 0) + __HAL_FLASH_PREFETCH_BUFFER_ENABLE(); +#endif /* PREFETCH_ENABLE */ + + /* Enable Power Control clock */ + __HAL_RCC_PWR_CLK_ENABLE(); + + /* The voltage scaling allows optimizing the power consumption when the device is + clocked below the maximum system frequency, to update the voltage scaling value + regarding system frequency refer to product datasheet. */ + __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1); + + /* Enable HSE and wait till HSE is ready */ + RCC->CR |= ((uint32_t)RCC_CR_HSEON); + while(__HAL_RCC_GET_FLAG(RCC_FLAG_HSERDY) == RESET) { + /* XXX: some error should occur here */ + } + + /* HCLK Configuration */ + MODIFY_REG(RCC->CFGR, RCC_CFGR_HPRE, RCC_SYSCLK_DIV1); + + /* PCLK1 Configuration */ + MODIFY_REG(RCC->CFGR, RCC_CFGR_PPRE1, RCC_HCLK_DIV4); + + /* PCLK2 Configuration */ + MODIFY_REG(RCC->CFGR, RCC_CFGR_PPRE2, (RCC_HCLK_DIV2 << 3)); + + /* Configure the main PLL clock source, multiplication and division factors. */ + WRITE_REG(RCC->PLLCFGR, (RCC_PLLSOURCE_HSE | \ + 12 | \ + (336 << POSITION_VAL(RCC_PLLCFGR_PLLN)) | \ + (((RCC_PLLP_DIV2 >> 1) -1) << POSITION_VAL(RCC_PLLCFGR_PLLP)) | \ + (7 << POSITION_VAL(RCC_PLLCFGR_PLLQ)))); + + /* Enable the main PLL. */ + __HAL_RCC_PLL_ENABLE(); + + /* Wait till PLL is ready */ + while(__HAL_RCC_GET_FLAG(RCC_FLAG_PLLRDY) == RESET) { + /* XXX: handle this */ + } + + /* Enable the Flash prefetch */ + __HAL_FLASH_PREFETCH_BUFFER_ENABLE(); + + /* Set flash wait states */ + __HAL_FLASH_SET_LATENCY(FLASH_LATENCY_5); + + /* Start PLL */ + __HAL_RCC_SYSCLK_CONFIG(RCC_SYSCLKSOURCE_PLLCLK); + + while (__HAL_RCC_GET_SYSCLK_SOURCE() != RCC_SYSCLKSOURCE_STATUS_PLLCLK) { + /* XXX: deal with this*/ + } +} + +/** + * @} + */ + +/** + * @} + */ + +/** + * @} + */ +/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/ |