nuttx/arch/arm/src/stm32/stm32_rcc.c
2016-06-16 16:22:01 -06:00

244 lines
7.5 KiB
C

/****************************************************************************
* arch/arm/src/stm32/stm32_rcc.c
*
* Copyright (C) 2009, 2011-2012 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 NuttX 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 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdio.h>
#include <assert.h>
#include <debug.h>
#include <arch/board/board.h>
#include "up_internal.h"
#include "up_arch.h"
#include "chip.h"
#include "stm32_rcc.h"
#include "stm32_rtc.h"
#include "stm32_flash.h"
#include "stm32.h"
#include "stm32_waste.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Allow up to 100 milliseconds for the high speed clock to become ready.
* that is a very long delay, but if the clock does not become ready we are
* hosed anyway.
*/
#define HSERDY_TIMEOUT (100 * CONFIG_BOARD_LOOPSPERMSEC)
/****************************************************************************
* Private Functions
****************************************************************************/
/* Include chip-specific clocking initialization logic */
#if defined(CONFIG_STM32_STM32L15XX)
# include "stm32l15xxx_rcc.c"
#elif defined(CONFIG_STM32_STM32F10XX)
# include "stm32f10xxx_rcc.c"
#elif defined(CONFIG_STM32_STM32F20XX)
# include "stm32f20xxx_rcc.c"
#elif defined(CONFIG_STM32_STM32F30XX)
# include "stm32f30xxx_rcc.c"
#elif defined(CONFIG_STM32_STM32F37XX)
# include "stm32f37xxx_rcc.c"
#elif defined(CONFIG_STM32_STM32F40XX)
# include "stm32f40xxx_rcc.c"
#else
# error "Unsupported STM32 chip"
#endif
#if defined(CONFIG_STM32_STM32L15XX)
# define STM32_RCC_XXX STM32_RCC_CSR
# define RCC_XXX_YYYRST RCC_CSR_RTCRST
#else
# define STM32_RCC_XXX STM32_RCC_BDCR
# define RCC_XXX_YYYRST RCC_BDCR_BDRST
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: rcc_resetbkp
*
* Description:
* The RTC needs to reset the Backup Domain to change RTCSEL and resetting
* the Backup Domain renders to disabling the LSE as consequence. In order
* to avoid resetting the Backup Domain when we already configured LSE we
* will reset the Backup Domain early (here).
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
#if defined(CONFIG_RTC) && defined(CONFIG_STM32_PWR) && !defined(CONFIG_STM32_STM32F10XX)
static inline void rcc_resetbkp(void)
{
uint32_t regval;
/* Check if the RTC is already configured */
regval = getreg32(RTC_MAGIC_REG);
if (regval != RTC_MAGIC)
{
(void)stm32_pwr_enablebkp(true);
/* We might be changing RTCSEL - to ensure such changes work, we must
* reset the backup domain (having backed up the RTC_MAGIC token)
*/
modifyreg32(STM32_RCC_XXX, 0, RCC_XXX_YYYRST);
modifyreg32(STM32_RCC_XXX, RCC_XXX_YYYRST, 0);
(void)stm32_pwr_enablebkp(false);
}
}
#else
# define rcc_resetbkp()
#endif
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: stm32_clockconfig
*
* Description:
* Called to establish the clock settings based on the values in board.h.
* This function (by default) will reset most everything, enable the PLL,
* and enable peripheral clocking for all peripherals enabled in the NuttX
* configuration file.
*
* If CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG is defined, then clocking
* will be enabled by an externally provided, board-specific function called
* stm32_board_clockconfig().
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
****************************************************************************/
void stm32_clockconfig(void)
{
/* Make sure that we are starting in the reset state */
rcc_reset();
/* Reset backup domain if appropriate */
rcc_resetbkp();
#if defined(CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG)
/* Invoke Board Custom Clock Configuration */
stm32_board_clockconfig();
#else
/* Invoke standard, fixed clock configuration based on definitions in board.h */
stm32_stdclockconfig();
#endif
/* Enable peripheral clocking */
rcc_enableperipherals();
}
/************************************************************************************
* Name: stm32_clockenable
*
* Description:
* Re-enable the clock and restore the clock settings based on settings in board.h.
* This function is only available to support low-power modes of operation: When
* re-awakening from deep-sleep modes, it is necessary to re-enable/re-start the
* PLL
*
* This functional performs a subset of the operations performed by
* stm32_clockconfig(): It does not reset any devices, and it does not reset the
* currenlty enabled peripheral clocks.
*
* If CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG is defined, then clocking will
* be enabled by an externally provided, board-specific function called
* stm32_board_clockconfig().
*
* Input Parameters:
* None
*
* Returned Value:
* None
*
************************************************************************************/
#ifdef CONFIG_PM
void stm32_clockenable(void)
{
#if defined(CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG)
/* Invoke Board Custom Clock Configuration */
stm32_board_clockconfig();
#else
/* Invoke standard, fixed clock configuration based on definitions in board.h */
stm32_stdclockconfig();
#endif
}
#endif