STM32F3 : json clock source configuration

- default value is the same as before patch
- system_stm32f3xx.c file is copied to family level with all other ST cube files
- specific clock configuration is now in a new file: system_clock.c (target level)

Author: jeromecoutant

targets/TARGET_STM/TARGET_STM32F3/TARGET_STM32F302x8/TARGET_NUCLEO_F302R8/system_clock.c

@@ -0,0 +1,231 @@
+/* mbed Microcontroller Library
+* Copyright (c) 2006-2017 ARM Limited
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*     http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+/**
+  * This file configures the system clock as follows:
+  *-----------------------------------------------------------------------------
+  * System clock source                | 1- USE_PLL_HSE_EXTC    | 3- USE_PLL_HSI
+  *                                    | (external 8 MHz clock) | (internal 8 MHz)
+  *                                    | 2- USE_PLL_HSE_XTAL    |
+  *                                    | (external 8 MHz xtal)  |
+  *-----------------------------------------------------------------------------
+  * SYSCLK(MHz)                        | 72                     | 64
+  *-----------------------------------------------------------------------------
+  * AHBCLK (MHz)                       | 72                     | 64
+  *-----------------------------------------------------------------------------
+  * APB1CLK (MHz)                      | 36                     | 32
+  *-----------------------------------------------------------------------------
+  * APB2CLK (MHz)                      | 72                     | 64
+  *-----------------------------------------------------------------------------
+  * USB capable                        | YES                    | NO
+  *-----------------------------------------------------------------------------
+  */
+
+
+#include "stm32f3xx.h"
+#include "mbed_assert.h"
+
+/*!< Uncomment the following line if you need to relocate your vector Table in
+     Internal SRAM. */
+/* #define VECT_TAB_SRAM */
+#define VECT_TAB_OFFSET  0x0 /*!< Vector Table base offset field.
+                                  This value must be a multiple of 0x200. */
+
+// clock source is selected with CLOCK_SOURCE in json config
+#define USE_PLL_HSE_EXTC     0x8  // Use external clock (ST Link MCO)
+#define USE_PLL_HSE_XTAL     0x4  // Use external xtal (X3 on board - not provided by default)
+#define USE_PLL_HSI          0x2  // Use HSI internal clock
+
+#if ( ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) )
+uint8_t SetSysClock_PLL_HSE(uint8_t bypass);
+#endif /* ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) */
+
+#if ((CLOCK_SOURCE) & USE_PLL_HSI)
+uint8_t SetSysClock_PLL_HSI(void);
+#endif /* ((CLOCK_SOURCE) & USE_PLL_HSI) */
+
+/**
+  * @brief  Setup the microcontroller system
+  *         Initialize the FPU setting, vector table location and the PLL configuration is reset.
+  * @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 |= 0x00000001U;
+
+    /* Reset CFGR register */
+    RCC->CFGR &= 0xF87FC00CU;
+
+    /* Reset HSEON, CSSON and PLLON bits */
+    RCC->CR &= 0xFEF6FFFFU;
+
+    /* Reset HSEBYP bit */
+    RCC->CR &= 0xFFFBFFFFU;
+
+    /* Reset PLLSRC, PLLXTPRE, PLLMUL and USBPRE bits */
+    RCC->CFGR &= 0xFF80FFFFU;
+
+    /* Reset PREDIV1[3:0] bits */
+    RCC->CFGR2 &= 0xFFFFFFF0U;
+
+    /* Reset USARTSW[1:0], I2CSW and TIMs bits */
+    RCC->CFGR3 &= 0xFF00FCCCU;
+
+    /* Disable all interrupts */
+    RCC->CIR = 0x00000000U;
+
+#ifdef VECT_TAB_SRAM
+    SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
+#else
+    SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
+#endif
+
+}
+
+
+/**
+  * @brief  Configures the System clock source, PLL Multiplier and Divider factors,
+  *               AHB/APBx prescalers and Flash settings
+  * @note   This function should be called only once the RCC clock configuration
+  *         is reset to the default reset state (done in SystemInit() function).
+  * @param  None
+  * @retval None
+  */
+
+void SetSysClock(void)
+{
+#if ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC)
+    /* 1- Try to start with HSE and external clock */
+    if (SetSysClock_PLL_HSE(1) == 0)
+#endif
+    {
+#if ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL)
+        /* 2- If fail try to start with HSE and external xtal */
+        if (SetSysClock_PLL_HSE(0) == 0)
+#endif
+        {
+#if ((CLOCK_SOURCE) & USE_PLL_HSI)
+            /* 3- If fail start with HSI clock */
+            if (SetSysClock_PLL_HSI() == 0)
+#endif
+            {
+                while(1) {
+                    MBED_ASSERT(1);
+                }
+            }
+        }
+    }
+
+    /* Output clock on MCO1 pin(PA8) for debugging purpose */
+    //HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_SYSCLK, RCC_MCO_DIV1); // 72 MHz or 64 MHz
+}
+
+#if ( ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) )
+/******************************************************************************/
+/*            PLL (clocked by HSE) used as System clock source                */
+/******************************************************************************/
+uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
+{
+    RCC_ClkInitTypeDef RCC_ClkInitStruct;
+    RCC_OscInitTypeDef RCC_OscInitStruct;
+    RCC_PeriphCLKInitTypeDef RCC_PeriphClkInit;
+
+    /* Enable HSE oscillator and activate PLL with HSE as source */
+    RCC_OscInitStruct.OscillatorType      = RCC_OSCILLATORTYPE_HSE;
+    if (bypass == 0) {
+        RCC_OscInitStruct.HSEState          = RCC_HSE_ON; /* External 8 MHz xtal on OSC_IN/OSC_OUT */
+    } else {
+        RCC_OscInitStruct.HSEState          = RCC_HSE_BYPASS; /* External 8 MHz clock on OSC_IN */
+    }
+    RCC_OscInitStruct.HSEPredivValue      = RCC_HSE_PREDIV_DIV1;
+    RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
+    RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSE;
+    RCC_OscInitStruct.PLL.PLLMUL          = RCC_PLL_MUL9; // 72 MHz (8 MHz * 9)
+    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
+    RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
+    RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 72 MHz
+    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 72 MHz
+    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;           // 36 MHz
+    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 72 MHz
+    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    RCC_PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;
+    RCC_PeriphClkInit.USBClockSelection = RCC_USBCLKSOURCE_PLL_DIV1_5;
+    if (HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphClkInit) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Output clock on MCO1 pin(PA8) for debugging purpose */
+    //if (bypass == 0)
+    //  HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSE, RCC_MCO_DIV2); // 4 MHz with xtal
+    //else
+    //  HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSE, RCC_MCO_DIV1); // 8 MHz with ext clock
+
+    return 1; // OK
+}
+#endif /* ((CLOCK_SOURCE) & USE_PLL_HSE_XTAL) || ((CLOCK_SOURCE) & USE_PLL_HSE_EXTC) */
+
+#if ((CLOCK_SOURCE) & USE_PLL_HSI)
+/******************************************************************************/
+/*            PLL (clocked by HSI) used as System clock source                */
+/******************************************************************************/
+uint8_t SetSysClock_PLL_HSI(void)
+{
+    RCC_ClkInitTypeDef RCC_ClkInitStruct;
+    RCC_OscInitTypeDef RCC_OscInitStruct;
+
+    /* Enable HSI oscillator and activate PLL with HSI as source */
+    RCC_OscInitStruct.OscillatorType      = RCC_OSCILLATORTYPE_HSI | RCC_OSCILLATORTYPE_HSE;
+    RCC_OscInitStruct.HSIState            = RCC_HSI_ON;
+    RCC_OscInitStruct.HSEState            = RCC_HSE_OFF;
+    RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
+    RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
+    RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSI;
+    RCC_OscInitStruct.PLL.PLLMUL          = RCC_PLL_MUL16; // 64 MHz (8 MHz/2 * 16)
+    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
+    RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
+    RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 64 MHz
+    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 64 MHz
+    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;           // 32 MHz
+    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 64 MHz
+    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Output clock on MCO1 pin(PA8) for debugging purpose */
+    //HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSI, RCC_MCO_DIV1); // 8 MHz
+
+    return 1; // OK
+}
+#endif /* ((CLOCK_SOURCE) & USE_PLL_HSI) */