STM32L1 : json clock source configuration

- default value is the same as before patch
- system_stm32l1xx.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_STM32L1/TARGET_MOTE_L152RC/device/system_clock.c

@@ -0,0 +1,236 @@
+/* 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- PLL_HSE_EXTC        | 3- PLL_HSI
+  *                                    | (external 8 MHz clock) | (internal 16 MHz)
+  *                                    | 2- PLL_HSE_XTAL        |
+  *                                    | (external 8 MHz xtal)  |
+  *-----------------------------------------------------------------------------
+  * SYSCLK(MHz)                        | 24                     | 32
+  *-----------------------------------------------------------------------------
+  * AHBCLK (MHz)                       | 24                     | 32
+  *-----------------------------------------------------------------------------
+  * APB1CLK (MHz)                      | 24                     | 32
+  *-----------------------------------------------------------------------------
+  * APB2CLK (MHz)                      | 24                     | 32
+  *-----------------------------------------------------------------------------
+  * USB capable (48 MHz precise clock) | YES                    | NO
+  *-----------------------------------------------------------------------------
+  ******************************************************************************
+  */
+
+#include "stm32l1xx.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. */
+
+/* Select the clock sources (other than HSI) to start with (0=OFF, 1=ON) */
+#define USE_PLL_HSE_EXTC (0) /* Use external clock */
+#define USE_PLL_HSE_XTAL (1) /* Use external xtal */
+
+
+#if (USE_PLL_HSE_XTAL != 0) || (USE_PLL_HSE_EXTC != 0)
+uint8_t SetSysClock_PLL_HSE(uint8_t bypass);
+#endif
+
+uint8_t SetSysClock_PLL_HSI(void);
+
+
+/**
+  * @brief  Setup the microcontroller system.
+  *         Initialize the Embedded Flash Interface, the PLL and update the
+  *         SystemCoreClock variable.
+  * @param  None
+  * @retval None
+  */
+void SystemInit (void)
+{
+    /*!< Set MSION bit */
+    RCC->CR |= (uint32_t)0x00000100;
+
+    /*!< Reset SW[1:0], HPRE[3:0], PPRE1[2:0], PPRE2[2:0], MCOSEL[2:0] and MCOPRE[2:0] bits */
+    RCC->CFGR &= (uint32_t)0x88FFC00C;
+
+    /*!< Reset HSION, HSEON, CSSON and PLLON bits */
+    RCC->CR &= (uint32_t)0xEEFEFFFE;
+
+    /*!< Reset HSEBYP bit */
+    RCC->CR &= (uint32_t)0xFFFBFFFF;
+
+    /*!< Reset PLLSRC, PLLMUL[3:0] and PLLDIV[1:0] bits */
+    RCC->CFGR &= (uint32_t)0xFF02FFFF;
+
+    /*!< Disable all interrupts */
+    RCC->CIR = 0x00000000;
+
+#ifdef DATA_IN_ExtSRAM
+    SystemInit_ExtMemCtl();
+#endif /* DATA_IN_ExtSRAM */
+
+#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)
+{
+    /* 1- Try to start with HSE and external clock */
+#if USE_PLL_HSE_EXTC != 0
+    if (SetSysClock_PLL_HSE(1) == 0)
+#endif
+    {
+        /* 2- If fail try to start with HSE and external xtal */
+#if USE_PLL_HSE_XTAL != 0
+        if (SetSysClock_PLL_HSE(0) == 0)
+#endif
+        {
+            /* 3- If fail start with HSI clock */
+            if (SetSysClock_PLL_HSI() == 0) {
+                while(1) {
+                    // [TODO] Put something here to tell the user that a problem occured...
+                }
+            }
+        }
+    }
+
+    /* Output clock on MCO1 pin(PA8) for debugging purpose */
+    //HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_SYSCLK, RCC_MCODIV_1);
+}
+
+#if (USE_PLL_HSE_XTAL != 0) || (USE_PLL_HSE_EXTC != 0)
+/******************************************************************************/
+/*            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;
+
+    if (__HAL_RCC_GET_SYSCLK_SOURCE() == RCC_CFGR_SWS_PLL)
+        return 1;   // already on HSE PLL, could occur from deepsleep waking
+
+    /* Used to gain time after DeepSleep in case HSI is used */
+    if (__HAL_RCC_GET_FLAG(RCC_FLAG_HSIRDY) != RESET) {
+        return 0;
+    }
+
+    /* 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. */
+    __PWR_CLK_ENABLE();
+    __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
+
+    /* Enable HSE and HSI48 oscillators 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.HSIState            = RCC_HSI_OFF;
+    // SYSCLK = 24 MHz ((8 MHz * 6) / 2)
+    // USBCLK = 48 MHz (8 MHz * 6) --> USB OK
+    RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
+    RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSE;
+    RCC_OscInitStruct.PLL.PLLMUL          = RCC_PLL_MUL6;
+    RCC_OscInitStruct.PLL.PLLDIV          = RCC_PLL_DIV2;
+    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; // 24 MHz
+    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 24 MHz
+    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;           // 24 MHz
+    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 24 MHz
+    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Output clock on MCO1 pin(PA8) for debugging purpose */
+    //if (bypass == 0)
+    //HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSE, RCC_MCODIV_2); // 4 MHz
+    //else
+    //HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSE, RCC_MCODIV_1); // 8 MHz
+
+    return 1; // OK
+}
+#endif
+
+/******************************************************************************/
+/*            PLL (clocked by HSI) used as System clock source                */
+/******************************************************************************/
+uint8_t SetSysClock_PLL_HSI(void)
+{
+    RCC_ClkInitTypeDef RCC_ClkInitStruct;
+    RCC_OscInitTypeDef RCC_OscInitStruct;
+
+    /* 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. */
+    __PWR_CLK_ENABLE();
+    __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
+
+    /* Enable HSI oscillator and activate PLL with HSI as source */
+    RCC_OscInitStruct.OscillatorType      = RCC_OSCILLATORTYPE_HSI;
+    RCC_OscInitStruct.HSEState            = RCC_HSE_OFF;
+    RCC_OscInitStruct.HSIState            = RCC_HSI_ON;
+    // SYSCLK = 32 MHz ((16 MHz * 4) / 2)
+    // USBCLK = 64 MHz (16 MHz * 4) --> USB not possible
+    RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
+    RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSI;
+    RCC_OscInitStruct.PLL.PLLMUL          = RCC_PLL_MUL4;
+    RCC_OscInitStruct.PLL.PLLDIV          = RCC_PLL_DIV2;
+    if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Poll VOSF bit of in PWR_CSR. Wait until it is reset to 0 */
+    while (__HAL_PWR_GET_FLAG(PWR_FLAG_VOS) != RESET) {};
+
+    /* 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; // 32 MHz
+    RCC_ClkInitStruct.AHBCLKDivider  = RCC_SYSCLK_DIV1;         // 32 MHz
+    RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;           // 32 MHz
+    RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;           // 32 MHz
+    if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
+        return 0; // FAIL
+    }
+
+    /* Output clock on MCO1 pin(PA8) for debugging purpose */
+    //HAL_RCC_MCOConfig(RCC_MCO1, RCC_MCO1SOURCE_HSI, RCC_MCODIV_1); // 16 MHz
+
+    return 1; // OK
+}