jackcartersmith/blackmagic
1
0
Fork 0
Code Issues Pull Requests Releases Activity
blackmagic/lib/stm32/f0/rcc.c
Karl Palsson 0259102560 stm32f0: drop superfluous intermediate speed helpers 
If you're interested in slightly underclocking or midrange speeds,
you're into custom environments.  Drop all the "helpers" for these odd
speeds.  This is not the max speed for any existing f0 part.

Signed-off-by: Karl Palsson <karlp@tweak.net.au>
2017-03-30 21:48:07 +00:00

667 lines
15 KiB
C
Raw Blame History

/** @defgroup STM32F0xx-rcc-file RCC
*
* @ingroup STM32F0xx
*
* @brief <b>libopencm3 STM32F0xx Reset and Clock Control</b>
*
* @version 1.0.0
*
* @date 29 Jun 2013
*
* This library supports the Reset and Clock Control System in the STM32F0xx
* series of ARM Cortex Microcontrollers by ST Microelectronics.
*
* LGPL License Terms @ref lgpl_license
*/
/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2009 Federico Ruiz-Ugalde <memeruiz at gmail dot com>
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
/**@{*/
#include <libopencm3/cm3/assert.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/flash.h>
/* Set the default clock frequencies */
uint32_t rcc_ahb_frequency = 8000000; /* 8MHz after reset */
uint32_t rcc_apb1_frequency = 8000000; /* 8MHz after reset */
/*---------------------------------------------------------------------------*/
/** @brief RCC Clear the Oscillator Ready Interrupt Flag
*
* Clear the interrupt flag that was set when a clock oscillator became ready
* to use.
*
* @param[in] osc enum ::osc_t. Oscillator ID
*/
void rcc_osc_ready_int_clear(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSI48:
RCC_CIR |= RCC_CIR_HSI48RDYC;
break;
case RCC_HSI14:
RCC_CIR |= RCC_CIR_HSI14RDYC;
break;
case RCC_HSI:
RCC_CIR |= RCC_CIR_HSIRDYC;
break;
case RCC_HSE:
RCC_CIR |= RCC_CIR_HSERDYC;
break;
case RCC_PLL:
RCC_CIR |= RCC_CIR_PLLRDYC;
break;
case RCC_LSE:
RCC_CIR |= RCC_CIR_LSERDYC;
break;
case RCC_LSI:
RCC_CIR |= RCC_CIR_LSIRDYC;
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Enable the Oscillator Ready Interrupt
*
* @param[in] osc enum ::osc_t. Oscillator ID
*/
void rcc_osc_ready_int_enable(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSI48:
RCC_CIR |= RCC_CIR_HSI48RDYIE;
break;
case RCC_HSI14:
RCC_CIR |= RCC_CIR_HSI14RDYIE;
break;
case RCC_HSI:
RCC_CIR |= RCC_CIR_HSIRDYIE;
break;
case RCC_HSE:
RCC_CIR |= RCC_CIR_HSERDYIE;
break;
case RCC_PLL:
RCC_CIR |= RCC_CIR_PLLRDYIE;
break;
case RCC_LSE:
RCC_CIR |= RCC_CIR_LSERDYIE;
break;
case RCC_LSI:
RCC_CIR |= RCC_CIR_LSIRDYIE;
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Disable the Oscillator Ready Interrupt
*
* @param[in] osc enum ::osc_t. Oscillator ID
*/
void rcc_osc_ready_int_disable(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSI48:
RCC_CIR &= ~RCC_CIR_HSI48RDYC;
break;
case RCC_HSI14:
RCC_CIR &= ~RCC_CIR_HSI14RDYC;
break;
case RCC_HSI:
RCC_CIR &= ~RCC_CIR_HSIRDYC;
break;
case RCC_HSE:
RCC_CIR &= ~RCC_CIR_HSERDYC;
break;
case RCC_PLL:
RCC_CIR &= ~RCC_CIR_PLLRDYC;
break;
case RCC_LSE:
RCC_CIR &= ~RCC_CIR_LSERDYC;
break;
case RCC_LSI:
RCC_CIR &= ~RCC_CIR_LSIRDYC;
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Read the Oscillator Ready Interrupt Flag
*
* @param[in] osc enum ::osc_t. Oscillator ID
* @returns int. Boolean value for flag set.
*/
int rcc_osc_ready_int_flag(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSI48:
return (RCC_CIR & RCC_CIR_HSI48RDYF) != 0;
break;
case RCC_HSI14:
return (RCC_CIR & RCC_CIR_HSI14RDYF) != 0;
break;
case RCC_HSI:
return (RCC_CIR & RCC_CIR_HSIRDYF) != 0;
break;
case RCC_HSE:
return (RCC_CIR & RCC_CIR_HSERDYF) != 0;
break;
case RCC_PLL:
return (RCC_CIR & RCC_CIR_PLLRDYF) != 0;
break;
case RCC_LSE:
return (RCC_CIR & RCC_CIR_LSERDYF) != 0;
break;
case RCC_LSI:
return (RCC_CIR & RCC_CIR_LSIRDYF) != 0;
break;
}
cm3_assert_not_reached();
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Clear the Clock Security System Interrupt Flag
*/
void rcc_css_int_clear(void)
{
RCC_CIR |= RCC_CIR_CSSC;
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Read the Clock Security System Interrupt Flag
*
* @returns int. Boolean value for flag set.
*/
int rcc_css_int_flag(void)
{
return ((RCC_CIR & RCC_CIR_CSSF) != 0);
}
bool rcc_is_osc_ready(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSI48:
return RCC_CR2 & RCC_CR2_HSI48RDY;
case RCC_HSI14:
return RCC_CR2 & RCC_CR2_HSI14RDY;
case RCC_HSI:
return RCC_CR & RCC_CR_HSIRDY;
case RCC_HSE:
return RCC_CR & RCC_CR_HSERDY;
case RCC_PLL:
return RCC_CR & RCC_CR_PLLRDY;
case RCC_LSE:
return RCC_BDCR & RCC_BDCR_LSERDY;
case RCC_LSI:
return RCC_CSR & RCC_CSR_LSIRDY;
}
return false;
}
void rcc_wait_for_osc_ready(enum rcc_osc osc)
{
while (!rcc_is_osc_ready(osc));
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Turn on an Oscillator.
*
* Enable an oscillator and power on. Each oscillator requires an amount of
* time to settle to a usable state. Refer to datasheets for time delay
* information. A status flag is available to indicate when the oscillator
* becomes ready (see @ref rcc_osc_ready_int_flag and @ref
* rcc_wait_for_osc_ready).
*
* @param[in] osc enum ::osc_t. Oscillator ID
*/
void rcc_osc_on(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSI48:
RCC_CR2 |= RCC_CR2_HSI48ON;
break;
case RCC_HSI14:
RCC_CR2 |= RCC_CR2_HSI14ON;
break;
case RCC_HSI:
RCC_CR |= RCC_CR_HSION;
break;
case RCC_HSE:
RCC_CR |= RCC_CR_HSEON;
break;
case RCC_LSE:
RCC_BDCR |= RCC_BDCR_LSEON;
break;
case RCC_LSI:
RCC_CSR |= RCC_CSR_LSION;
break;
case RCC_PLL:
RCC_CR |= RCC_CR_PLLON;
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Turn off an Oscillator.
*
* Disable an oscillator and power off.
*
* @note An oscillator cannot be turned off if it is selected as the system
* clock.
*
* @param[in] osc enum ::osc_t. Oscillator ID
*/
void rcc_osc_off(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSI48:
RCC_CR2 &= ~RCC_CR2_HSI48ON;
break;
case RCC_HSI14:
RCC_CR2 &= ~RCC_CR2_HSI14ON;
break;
case RCC_HSI:
RCC_CR &= ~RCC_CR_HSION;
break;
case RCC_HSE:
RCC_CR &= ~RCC_CR_HSEON;
break;
case RCC_LSE:
RCC_BDCR &= ~RCC_BDCR_LSEON;
break;
case RCC_LSI:
RCC_CSR &= ~RCC_CSR_LSION;
break;
case RCC_PLL:
/* don't do anything */
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Enable the Clock Security System.
*/
void rcc_css_enable(void)
{
RCC_CR |= RCC_CR_CSSON;
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Disable the Clock Security System.
*/
void rcc_css_disable(void)
{
RCC_CR &= ~RCC_CR_CSSON;
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Enable Bypass.
*
* Enable an external clock to bypass the internal clock (high speed and low
* speed clocks only). The external clock must be enabled (see @ref rcc_osc_on)
* and the internal clock must be disabled (see @ref rcc_osc_off) for this to
* have effect.
*
* @param[in] osc enum ::osc_t. Oscillator ID. Only HSE and LSE have effect.
*/
void rcc_osc_bypass_enable(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSE:
RCC_CR |= RCC_CR_HSEBYP;
break;
case RCC_LSE:
RCC_BDCR |= RCC_BDCR_LSEBYP;
break;
case RCC_HSI48:
case RCC_HSI14:
case RCC_HSI:
case RCC_LSI:
case RCC_PLL:
/* Do nothing */
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Disable Bypass.
*
* Re-enable the internal clock (high speed and low speed clocks only). The
* internal clock must be disabled (see @ref rcc_osc_off) for this to have
* effect.
*
*
* @param[in] osc enum ::osc_t. Oscillator ID. Only HSE and LSE have effect.
*/
void rcc_osc_bypass_disable(enum rcc_osc osc)
{
switch (osc) {
case RCC_HSE:
RCC_CR &= ~RCC_CR_HSEBYP;
break;
case RCC_LSE:
RCC_BDCR &= ~RCC_BDCR_LSEBYP;
break;
case RCC_HSI48:
case RCC_HSI14:
case RCC_PLL:
case RCC_HSI:
case RCC_LSI:
/* Do nothing */
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the Source for the System Clock.
*
* @param[in] osc enum ::osc_t. Oscillator ID. Only HSE, LSE and PLL have
* effect.
*/
void rcc_set_sysclk_source(enum rcc_osc clk)
{
switch (clk) {
case RCC_HSI:
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSI;
break;
case RCC_HSE:
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSE;
break;
case RCC_PLL:
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_PLL;
break;
case RCC_HSI48:
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSI48;
break;
case RCC_LSI:
case RCC_LSE:
case RCC_HSI14:
/* do nothing */
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the Source for the USB Clock.
*
* @param[in] osc enum ::osc_t. Oscillator ID. Only HSI48 or PLL have
* effect.
*/
void rcc_set_usbclk_source(enum rcc_osc clk)
{
switch (clk) {
case RCC_PLL:
RCC_CFGR3 |= RCC_CFGR3_USBSW;
break;
case RCC_HSI48:
RCC_CFGR3 &= ~RCC_CFGR3_USBSW;
break;
case RCC_HSI:
case RCC_HSE:
case RCC_LSI:
case RCC_LSE:
case RCC_HSI14:
/* do nothing */
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Enable the RTC clock
*/
void rcc_enable_rtc_clock(void)
{
RCC_BDCR |= RCC_BDCR_RTCEN;
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Disable the RTC clock
*/
void rcc_disable_rtc_clock(void)
{
RCC_BDCR &= ~RCC_BDCR_RTCEN;
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the Source for the RTC clock
@param[in] clock_source ::rcc_osc. RTC clock source. Only HSE/32, LSE and LSI.
*/
void rcc_set_rtc_clock_source(enum rcc_osc clk)
{
switch (clk) {
case RCC_HSE:
RCC_BDCR = (RCC_BDCR & ~RCC_BDCR_RTCSEL) | RCC_BDCR_RTCSEL_HSE;
break;
case RCC_LSE:
RCC_BDCR = (RCC_BDCR & ~RCC_BDCR_RTCSEL) | RCC_BDCR_RTCSEL_LSE;
break;
case RCC_LSI:
RCC_BDCR = (RCC_BDCR & ~RCC_BDCR_RTCSEL) | RCC_BDCR_RTCSEL_LSI;
break;
default:
/* do nothing */
break;
}
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the PLL Multiplication Factor.
*
* @note This only has effect when the PLL is disabled.
*
* @param[in] mul Unsigned int32. PLL multiplication factor @ref rcc_cfgr_pmf
*/
void rcc_set_pll_multiplication_factor(uint32_t mul)
{
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_PLLMUL) | mul;
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the PLL Clock Source.
@note This only has effect when the PLL is disabled.
@param[in] pllsrc Unsigned int32. PLL clock source @ref rcc_cfgr_pcs
*/
void rcc_set_pll_source(uint32_t pllsrc)
{
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_PLLSRC) |
(pllsrc << 16);
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the HSE Frequency Divider used as PLL Clock Source.
@note This only has effect when the PLL is disabled.
@param[in] pllxtpre Unsigned int32. HSE division factor @ref rcc_cfgr_hsepre
*/
void rcc_set_pllxtpre(uint32_t pllxtpre)
{
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_PLLXTPRE) |
(pllxtpre << 17);
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the APB Prescale Factor.
*
* @param[in] ppre1 Unsigned int32. APB prescale factor @ref rcc_cfgr_apb1pre
*/
void rcc_set_ppre(uint32_t ppre)
{
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_PPRE) | ppre;
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Set the AHB Prescale Factor.
*
* @param[in] hpre Unsigned int32. AHB prescale factor @ref rcc_cfgr_ahbpre
*/
void rcc_set_hpre(uint32_t hpre)
{
RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_HPRE) | hpre;
}
/**
* Set PLL Source pre-divider **CAUTION**.
* On F03x and F05, prediv only applies to HSE source. On others, this
* is _after_ source selection. See also f3.
* @param[in] prediv division by prediv+1 @ref rcc_cfgr2_prediv
*/
void rcc_set_prediv(uint32_t prediv)
{
RCC_CFGR2 = (RCC_CFGR2 & ~RCC_CFGR2_PREDIV) | prediv;
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Get the System Clock Source.
*
* @returns ::osc_t System clock source:
*/
enum rcc_osc rcc_system_clock_source(void)
{
/* Return the clock source which is used as system clock. */
switch (RCC_CFGR & RCC_CFGR_SWS) {
case RCC_CFGR_SWS_HSI:
return RCC_HSI;
case RCC_CFGR_SWS_HSE:
return RCC_HSE;
case RCC_CFGR_SWS_PLL:
return RCC_PLL;
case RCC_CFGR_SWS_HSI48:
return RCC_HSI48;
}
cm3_assert_not_reached();
}
/*---------------------------------------------------------------------------*/
/** @brief RCC Get the USB Clock Source.
*
* @returns ::osc_t USB clock source:
*/
enum rcc_osc rcc_usb_clock_source(void)
{
return (RCC_CFGR3 & RCC_CFGR3_USBSW) ? RCC_PLL : RCC_HSI48;
}
/**
* Set System Clock PLL at 48MHz from HSE at 8MHz.
*/
void rcc_clock_setup_in_hse_8mhz_out_48mhz(void)
{
rcc_osc_on(RCC_HSE);
rcc_wait_for_osc_ready(RCC_HSE);
rcc_set_sysclk_source(RCC_HSE);
rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
/* PLL: 8MHz * 6 = 48MHz */
rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_MUL6);
rcc_set_pll_source(RCC_CFGR_PLLSRC_HSE_CLK);
rcc_set_pllxtpre(RCC_CFGR_PLLXTPRE_HSE_CLK);
rcc_osc_on(RCC_PLL);
rcc_wait_for_osc_ready(RCC_PLL);
rcc_set_sysclk_source(RCC_PLL);
rcc_apb1_frequency = 48000000;
rcc_ahb_frequency = 48000000;
}
/**
* Set System Clock PLL at 48MHz from HSI
*/
void rcc_clock_setup_in_hsi_out_48mhz(void)
{
rcc_osc_on(RCC_HSI);
rcc_wait_for_osc_ready(RCC_HSI);
rcc_set_sysclk_source(RCC_HSI);
rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
/* 8MHz * 12 / 2 = 48MHz */
rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_MUL12);
rcc_set_pll_source(RCC_CFGR_PLLSRC_HSI_CLK_DIV2);
rcc_osc_on(RCC_PLL);
rcc_wait_for_osc_ready(RCC_PLL);
rcc_set_sysclk_source(RCC_PLL);
rcc_apb1_frequency = 48000000;
rcc_ahb_frequency = 48000000;
}
/**
* Set System Clock HSI48 at 48MHz
*/
void rcc_clock_setup_in_hsi48_out_48mhz(void)
{
rcc_osc_on(RCC_HSI48);
rcc_wait_for_osc_ready(RCC_HSI48);
rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
rcc_set_sysclk_source(RCC_HSI48);
rcc_apb1_frequency = 48000000;
rcc_ahb_frequency = 48000000;
}
/**@}*/
Reference in New Issue View Git Blame Copy Permalink