2.3-InternetRadio/nutos/nut/arch/cm3/dev/stm/system_stm32.c

/*
 * Copyright (C) 2013 by Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
 *
 * All rights reserved.
 *
 * 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 the copyright holders nor the names of
 *    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 OWNER 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.
 *
 * For additional information see http://www.ethernut.de/
 */

#include <stdint.h>
#include <cfg/arch.h>
#include <arch/cm3/stm/stm32xxxx.h>
#if defined(RCC_CR_MSION)
#define RCC_CR_RESET_VALUE RCC_CR_MSION 
#else
#if !defined(RCC_CR_HSITRIM_4)
#define RCC_CR_RESET_VALUE (RCC_CR_HSION | 0x80)
#else
#define RCC_CR_RESET_VALUE (RCC_CR_HSION | RCC_CR_HSITRIM_4)
#endif
#endif

/** @addtogroup STM32_System_Defines
  * @{
  */

/**
 * Initialize the system
 *
 * @param  none
 * @return none
 *
 * @brief  Setup the microcontroller system.
 *         Switch back to default clock state.
 *
 *         We write the default reset values to the appropriated registers.
 *         Some bits can only be written in certain constellation, so we write
 *         multiple time, as previous writes prepare these constellations.
 *         We keep eventual CIR IRQ pendings flags hanging...
 */
void SystemInit (void)
{
    RCC_TypeDef *rcc = (RCC_TypeDef *) RCC_BASE;

    /* FPU settings ---------------------------------------------------------*/
#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
    /* set CP10 and CP11 Full Access */
    SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); 
#endif
    /* Disable clock related interrupts*/
    rcc->CIR = 0;
    /* Switch on HSI Clock */
    rcc->CR = RCC_CR_RESET_VALUE;
    rcc->CFGR = 0;
    /* Now HSEON, CSSON and PLLON should reset*/
    rcc->CR   = RCC_CR_RESET_VALUE;
#if defined(RCC_PLLCFGR_PLLM)
    /* Reset PLLSRC, PLLXTPRE, PLLMUL and USBPRE bits */
    rcc->PLLCFGR = 0;
#endif
    /* Now HSEBYP should reset*/
    rcc->CR = RCC_CR_RESET_VALUE;
#if defined(RCC_CFGR_PLLSRC)
    /* Reset PLL bits*/
    rcc->CFGR = 0;
#endif
#if defined(RCC_CFGR2_PREDIV1)
    rcc->CFGR2 = 0;
#endif
#if defined(RCC_CFGR3_USART1SW1)
    rcc->CFGR3 = 0;
#endif
/* Seperate USB and CAN interrupts on F30 */
#if defined(STM32F30X)
    rcc->APB2ENR |= RCC_APB2ENR_SYSCFGEN;
    SYSCFG_TypeDef *syscfg = (SYSCFG_TypeDef *) SYSCFG_BASE;
    syscfg->CFGR1 |= SYSCFG_CFGR1_USB_IT_RMP;
#endif

}

/**
 * @}
 */