/****************************************************************************
* arch/arm/src/stm32/stm32_rcc.c
*
* Copyright (C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <sys/types.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_flash.h"
#include "stm32_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
#define HSERDY_TIMEOUT 256
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/* Put all RCC registers in reset state */
static inline void rcc_reset(void)
{
uint32 regval;
putreg32(0, STM32_RCC_APB2RSTR); /* Disable APB2 Peripheral Reset */
putreg32(0, STM32_RCC_APB1RSTR); /* Disable APB1 Peripheral Reset */
putreg32(RCC_AHBENR_FLITFEN|RCC_AHBENR_SRAMEN, STM32_RCC_AHBENR); /* FLITF and SRAM Clock ON */
putreg32(0, STM32_RCC_APB2ENR); /* Disable APB2 Peripheral Clock */
putreg32(0, STM32_RCC_APB1ENR); /* Disable APB1 Peripheral Clock */
regval = getreg32(STM32_RCC_CR); /* Set the HSION bit */
regval |= RCC_CR_HSION;
putreg32(regval, STM32_RCC_CR);
regval = getreg32(STM32_RCC_CFGR); /* Reset SW, HPRE, PPRE1, PPRE2, ADCPRE and MCO bits */
regval &= ~(RCC_CFGR_SW_MASK|RCC_CFGR_HPRE_MASK|RCC_CFGR_PPRE1_MASK|RCC_CFGR_PPRE2_MASK|RCC_CFGR_ADCPRE_MASK|RCC_CFGR_MCO_MASK);
putreg32(regval, STM32_RCC_CFGR);
regval = getreg32(STM32_RCC_CR); /* Reset HSEON, CSSON and PLLON bits */
regval &= ~(RCC_CR_HSEON|RCC_CR_CSSON|RCC_CR_PLLON);
putreg32(regval, STM32_RCC_CR);
regval = getreg32(STM32_RCC_CR); /* Reset HSEBYP bit */
regval &= ~RCC_CR_HSEBYP;
putreg32(regval, STM32_RCC_CR);
regval = getreg32(STM32_RCC_CFGR); /* Reset PLLSRC, PLLXTPRE, PLLMUL and USBPRE bits */
regval &= ~(RCC_CFGR_PLLSRC|RCC_CFGR_PLLXTPRE|RCC_CFGR_PLLMUL_MASK|RCC_CFGR_USBPRE);
putreg32(regval, STM32_RCC_CFGR);
putreg32(0, STM32_RCC_CIR); /* Disable all interrupts */
}
static inline void rcc_enableahb(void)
{
uint32 regval;
/* Always enable FLITF clock and SRAM clock */
regval = RCC_AHBENR_FLITFEN|RCC_AHBENR_SRAMEN;
#if CONFIG_STM32_DMA1
/* DMA 1 clock enable */
regval |= RCC_AHBENR_DMA1EN;
#endif
#if CONFIG_STM32_DMA2
/* DMA 2 clock enable */
regval |= RCC_AHBENR_DMA2EN;
#endif
#if CONFIG_STM32_CRC
/* CRC clock enable */
regval |= RCC_AHBENR_CRCEN;
#endif
#if CONFIG_STM32_FSMC
/* FSMC clock enable */
regval |= RCC_AHBENR_FSMCEN;
#endif
#if CONFIG_STM32_SDIO
/* SDIO clock enable */
regval |= RCC_AHBENR_SDIOEN;
#endif
putreg32(regval, STM32_RCC_AHBENR); /* Enable peripherals */
}
static inline void rcc_enableapb1(void)
{
uint32 regval;
#if CONFIG_STM32_USB
/* USB clock divider. This bit must be valid before enabling the USB
* clock in the RCC_APB1ENR register. This bit can�t be reset if the USB
* clock is enabled.
*/
regval = getreg32(STM32_RCC_CFGR);
regval &= ~RCC_CFGR_USBPRE;
regval |= STM32_CFGR_USBPRE;
putreg32(regval, STM32_RCC_CFGR);
#endif
/* Set the appropriate bits in the APB1ENR register to enabled the
* selected APB1 peripherals.
*/
regval = getreg32(STM32_RCC_APB1ENR);
#if CONFIG_STM32_TIM2
/* Timer 2 clock enable */
regval |= RCC_APB1ENR_TIM2EN;
#endif
#if CONFIG_STM32_TIM3
/* Timer 3 clock enable */
regval |= RCC_APB1ENR_TIM3EN;
#endif
#if CONFIG_STM32_TIM4
/* Timer 4 clock enable */
regval |= RCC_APB1ENR_TIM4EN;
#endif
#if CONFIG_STM32_TIM5
/* Timer 5 clock enable */
regval |= RCC_APB1ENR_TIM5EN;
#endif
#if CONFIG_STM32_TIM6
/* Timer 6 clock enable */
regval |= RCC_APB1ENR_TIM6EN;
#endif
#if CONFIG_STM32_TIM7
/* Timer 7 clock enable */
regval |= RCC_APB1ENR_TIM7EN;
#endif
#if CONFIG_STM32_WWDG
/* Window Watchdog clock enable */
regval |= RCC_APB1ENR_WWDGEN;
#endif
#if CONFIG_STM32_SPI2
/* SPI 2 clock enable */
regval |= RCC_APB1ENR_SPI2EN;
#endif
#if CONFIG_STM32_SPI4
/* SPI 3 clock enable */
regval |= RCC_APB1ENR_SPI3EN;
#endif
#if CONFIG_STM32_USART2
/* USART 2 clock enable */
regval |= RCC_APB1ENR_USART2EN;
#endif
#if CONFIG_STM32_USART3
/* USART 3 clock enable */
regval |= RCC_APB1ENR_USART3EN;
#endif
#if CONFIG_STM32_UART4
/* UART 4 clock enable */
regval |= RCC_APB1ENR_UART4EN;
#endif
#if CONFIG_STM32_UART5
/* UART 5 clock enable */
regval |= RCC_APB1ENR_UART5EN;
#endif
#if CONFIG_STM32_I2C1
/* I2C 1 clock enable */
regval |= RCC_APB1ENR_I2C1EN;
#endif
#if CONFIG_STM32_I2C2
/* I2C 2 clock enable */
regval |= RCC_APB1ENR_I2C2EN;
#endif
#if CONFIG_STM32_USB
/* USB clock enable */
regval |= RCC_APB1ENR_USBEN;
#endif
#if CONFIG_STM32_CAN
/* CAN clock enable */
regval |= RCC_APB1ENR_CANEN;
#endif
#if CONFIG_STM32_BKP
/* Backup interface clock enable */
regval |= RCC_APB1ENR_BKPEN;
#endif
#if CONFIG_STM32_PWR
/* Power interface clock enable */
regval |= RCC_APB1ENR_PWREN;
#endif
#if CONFIG_STM32_DAC
/* DAC interface clock enable */
regval |= RCC_APB1ENR_DACEN;
#endif
putreg32(regval, STM32_RCC_APB1ENR);
}
static inline void rcc_enableapb2(void)
{
uint32 regval;
/* Set the appropriate bits in the APB2ENR register to enabled the
* selected APB2 peripherals.
*/
/* Enable GPIOA, GPIOB, ... and AFIO clocks */
regval = getreg32(STM32_RCC_APB2ENR);
regval |= (RCC_APB2ENR_AFIOEN
#if STM32_NGPIO > 0
|RCC_APB2ENR_IOPAEN
#endif
#if STM32_NGPIO > 16
|RCC_APB2ENR_IOPBEN
#endif
#if STM32_NGPIO > 32
|RCC_APB2ENR_IOPCEN
#endif
#if STM32_NGPIO > 48
|RCC_APB2ENR_IOPDEN
#endif
#if STM32_NGPIO > 64
|RCC_APB2ENR_IOPEEN
#endif
#if STM32_NGPIO > 80
|RCC_APB2ENR_IOPFEN
#endif
#if STM32_NGPIO > 96
|RCC_APB2ENR_IOPGEN
#endif
);
#if CONFIG_STM32_ADC1
/* ADC 1 interface clock enable */
regval |= RCC_APB2ENR_ADC1EN;
#endif
#if CONFIG_STM32_ADC2
/* ADC 2 interface clock enable */
regval |= RCC_APB2ENR_ADC2EN;
#endif
#if CONFIG_STM32_TIM1
/* TIM1 Timer clock enable */
regval |= RCC_APB2ENR_TIM1EN;
#endif
#if CONFIG_STM32_SPI1
/* SPI 1 clock enable */
regval |= RCC_APB2ENR_SPI1EN;
#endif
#if CONFIG_STM32_TIM8
/* TIM8 Timer clock enable */
regval |= RCC_APB2ENR_TIM8EN;
#endif
#if CONFIG_STM32_USART1
/* USART1 clock enable */
regval |= RCC_APB2ENR_USART1EN;
#endif
#if CONFIG_STM32_ADC3
/*ADC3 interface clock enable */
regval |= RCC_APB2ENR_ADC3EN;
#endif
putreg32(regval, STM32_RCC_APB2ENR);
}
/****************************************************************************
* Global Functions
****************************************************************************/
/****************************************************************************
* Name: stm32_clockconfig
*
* Description:
* Called to change to new clock based on settings in board.h.
* NOTE: This logic needs to be extended so that we can selected low-power
* clocking modes as well!
*
****************************************************************************/
void stm32_clockconfig(void)
{
uint32 regval;
volatile sint32 timeout;
/* Make sure that we are starting in the reset state */
rcc_reset();
/* Enable External High-Speed Clock (HSE) */
regval = getreg32(STM32_RCC_CR);
regval &= ~RCC_CR_HSEBYP; /* Disable HSE clock bypass */
regval |= RCC_CR_HSEON; /* Enable HSE */
putreg32(regval, STM32_RCC_CR);
/* Wait until the HSE is ready (or until a timeout elapsed) */
for (timeout = HSERDY_TIMEOUT; timeout > 0; timeout--)
{
/* Check if the HSERDY flag is the set in the CR */
if ((getreg32(STM32_RCC_CR) & RCC_CR_HSERDY) != 0)
{
/* If so, then break-out with timeout > 0 */
break;
}
}
if( timeout > 0)
{
/* Enable FLASH prefetch buffer and 2 wait states */
regval = getreg32(STM32_FLASH_ACR);
regval &= ~ACR_LATENCY_MASK;
regval |= (ACR_LATENCY_2|ACR_PRTFBE);
putreg32(regval, STM32_FLASH_ACR);
/* Set the HCLK source/divider */
regval = getreg32(STM32_RCC_CFGR);
regval &= ~RCC_CFGR_HPRE_MASK;
regval |= STM32_RCC_CFGR_HPRE;
putreg32(regval, STM32_RCC_CFGR);
/* Set the PCLK2 divider */
regval = getreg32(STM32_RCC_CFGR);
regval &= ~RCC_CFGR_PPRE2_MASK;
regval |= STM32_RCC_CFGR_PPRE2;
putreg32(regval, STM32_RCC_CFGR);
/* Set the PCLK1 divider */
regval = getreg32(STM32_RCC_CFGR);
regval &= ~RCC_CFGR_PPRE1_MASK;
regval |= STM32_RCC_CFGR_PPRE1;
putreg32(regval, STM32_RCC_CFGR);
/* Set the PLL divider and multipler */
regval = getreg32(STM32_RCC_CFGR);
regval &= ~(RCC_CFGR_PLLSRC|RCC_CFGR_PLLXTPRE|RCC_CFGR_PLLMUL_MASK);
regval |= (STM32_CFGR_PLLSRC|STM32_CFGR_PLLXTPRE|STM32_CFGR_PLLMUL);
putreg32(regval, STM32_RCC_CFGR);
/* Enable the PLL */
regval = getreg32(STM32_RCC_CR);
regval |= RCC_CR_PLLON;
putreg32(regval, STM32_RCC_CR);
/* Wait until the PLL is ready */
while ((getreg32(STM32_RCC_CR) & RCC_CR_PLLRDY) == 0);
/* Select the system clock source (probably the PLL) */
regval = getreg32(STM32_RCC_CFGR);
regval &= ~RCC_CFGR_SW_MASK;
regval |= STM32_SYSCLK_SW;
putreg32(regval, STM32_RCC_CFGR);
/* Wait until the selected source is used as the system clock source */
while ((getreg32(STM32_RCC_CFGR) & RCC_CFGR_SWS_MASK) != STM32_SYSCLK_SWS);
}
/* Enable peripheral clocking */
rcc_enableahb();
rcc_enableapb2();
rcc_enableapb1();
}