system(f7): update STM32F7xx system

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>

Author: fpistm

system/STM32F7xx/system_stm32f7xx.c

@@ -4,16 +4,16 @@
   * @author  MCD Application Team
   * @brief   CMSIS Cortex-M7 Device Peripheral Access Layer System Source File.
   *
-  *   This file provides two functions and one global variable to be called from 
+  *   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 
+  *      - SystemInit(): This function is called at startup just after reset and
   *                      before branch to main program. This call is made inside
   *                      the "startup_stm32f7xx.s" file.
   *
   *      - SystemCoreClock variable: Contains the core clock (HCLK), it can be used
-  *                                  by the user application to setup the SysTick 
+  *                                  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.
@@ -38,8 +38,8 @@
 
 /** @addtogroup stm32f7xx_system
   * @{
-  */  
-  
+  */
+
 /** @addtogroup STM32F7xx_System_Private_Includes
   * @{
   */
@@ -65,13 +65,12 @@
 /************************* Miscellaneous Configuration ************************/
 /* Note: Following vector table addresses must be defined in line with linker
          configuration. */
-
 /*!< Uncomment the following line and change the address
      if you need to relocate your vector Table at a custom base address (+ VECT_TAB_OFFSET) */
 /* #define VECT_TAB_BASE_ADDRESS 0x08000000 */
 
 /*!< Uncomment the following line if you need to relocate your vector Table
-     in Sram else user remap will be done by default in Flash. */
+     in Sram else user remap will be done in Flash. */
 /* #define VECT_TAB_SRAM */
 
 #ifndef VECT_TAB_OFFSET
@@ -110,7 +109,7 @@
   /* 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 
+      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.
@@ -137,7 +136,7 @@
 
 /**
   * @brief  Setup the microcontroller system
-  *         Initialize the Embedded Flash Interface, the PLL and update the 
+  *         Initialize the Embedded Flash Interface, the PLL and update the
   *         SystemFrequency variable.
   * @param  None
   * @retval None
@@ -177,41 +176,41 @@ void SystemInit(void)
   *         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 
+  *         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(**) 
+  *
+  *           - 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 stm32f7xx_hal_conf.h file (default value
   *             16 MHz) but the real value may vary depending on the variations
-  *             in voltage and temperature.   
-  *    
+  *             in voltage and temperature.
+  *
   *         (**) HSE_VALUE is a constant defined in stm32f7xx_hal_conf.h file (default value
   *              25 MHz), 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;
-  
+  uint32_t tmp, pllvco, pllp, pllsource, pllm;
+
   /* Get SYSCLK source -------------------------------------------------------*/
   tmp = RCC->CFGR & RCC_CFGR_SWS;
 
@@ -227,10 +226,10 @@ void SystemCoreClockUpdate(void)
 
       /* 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 */
@@ -239,7 +238,7 @@ void SystemCoreClockUpdate(void)
       else
       {
         /* HSI used as PLL clock source */
-        pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);      
+        pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
       }
 
       pllp = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLP) >>16) + 1 ) *2;
@@ -263,7 +262,7 @@ void SystemCoreClockUpdate(void)
 /**
   * @}
   */
-  
+
 /**
   * @}
-  */    
+  */