637 lines
16 KiB
C
637 lines
16 KiB
C
|
/** @defgroup rcc_file RCC peripheral API
|
||
|
*
|
||
|
* @ingroup peripheral_apis
|
||
|
*
|
||
|
* @section rcc_l4_api_ex Reset and Clock Control API.
|
||
|
*
|
||
|
* @brief <b>libopencm3 STM32L4xx Reset and Clock Control</b>
|
||
|
*
|
||
|
* @author @htmlonly © @endhtmlonly 2016 Karl Palsson <karlp@tweak.net.au>
|
||
|
*
|
||
|
* @date 12 Feb 2016
|
||
|
*
|
||
|
* This library supports the Reset and Clock Control System in the STM32 series
|
||
|
* of ARM Cortex Microcontrollers by ST Microelectronics.
|
||
|
*
|
||
|
* LGPL License Terms @ref lgpl_license
|
||
|
*/
|
||
|
|
||
|
/*
|
||
|
* This file is part of the libopencm3 project.
|
||
|
*
|
||
|
* Copyright (C) 2016 Karl Palsson <karlp@tweak.net.au>
|
||
|
*
|
||
|
* 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>
|
||
|
#include <libopencm3/stm32/pwr.h>
|
||
|
|
||
|
/* Set the default clock frequencies after reset. */
|
||
|
uint32_t rcc_ahb_frequency = 4000000;
|
||
|
uint32_t rcc_apb1_frequency = 4000000;
|
||
|
uint32_t rcc_apb2_frequency = 4000000;
|
||
|
|
||
|
const struct rcc_clock_scale rcc_hsi16_configs[RCC_CLOCK_CONFIG_END] = {
|
||
|
{ /* 80MHz PLL from HSI16 VR1 */
|
||
|
.pllm = 4,
|
||
|
.plln = 40,
|
||
|
.pllp = RCC_PLLCFGR_PLLP_DIV7,
|
||
|
.pllq = RCC_PLLCFGR_PLLQ_DIV6,
|
||
|
.pllr = RCC_PLLCFGR_PLLR_DIV2,
|
||
|
.pll_source = RCC_PLLCFGR_PLLSRC_HSI16,
|
||
|
.hpre = RCC_CFGR_HPRE_NODIV,
|
||
|
.ppre1 = RCC_CFGR_PPRE_NODIV,
|
||
|
.ppre2 = RCC_CFGR_PPRE_NODIV,
|
||
|
.voltage_scale = PWR_SCALE1,
|
||
|
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
|
||
|
FLASH_ACR_LATENCY_4WS,
|
||
|
.ahb_frequency = 80000000,
|
||
|
.apb1_frequency = 80000000,
|
||
|
.apb2_frequency = 80000000,
|
||
|
},
|
||
|
};
|
||
|
|
||
|
void rcc_osc_ready_int_clear(enum rcc_osc osc)
|
||
|
{
|
||
|
switch (osc) {
|
||
|
case RCC_PLL:
|
||
|
RCC_CICR |= RCC_CICR_PLLRDYC;
|
||
|
break;
|
||
|
case RCC_HSE:
|
||
|
RCC_CICR |= RCC_CICR_HSERDYC;
|
||
|
break;
|
||
|
case RCC_HSI16:
|
||
|
RCC_CICR |= RCC_CICR_HSIRDYC;
|
||
|
break;
|
||
|
case RCC_MSI:
|
||
|
RCC_CICR |= RCC_CICR_MSIRDYC;
|
||
|
break;
|
||
|
case RCC_LSE:
|
||
|
RCC_CICR |= RCC_CICR_LSERDYC;
|
||
|
break;
|
||
|
case RCC_LSI:
|
||
|
RCC_CICR |= RCC_CICR_LSIRDYC;
|
||
|
break;
|
||
|
case RCC_HSI48:
|
||
|
RCC_CICR |= RCC_CICR_HSI48RDYC;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void rcc_osc_ready_int_enable(enum rcc_osc osc)
|
||
|
{
|
||
|
switch (osc) {
|
||
|
case RCC_PLL:
|
||
|
RCC_CIER |= RCC_CIER_PLLRDYIE;
|
||
|
break;
|
||
|
case RCC_HSE:
|
||
|
RCC_CIER |= RCC_CIER_HSERDYIE;
|
||
|
break;
|
||
|
case RCC_HSI16:
|
||
|
RCC_CIER |= RCC_CIER_HSIRDYIE;
|
||
|
break;
|
||
|
case RCC_MSI:
|
||
|
RCC_CIER |= RCC_CIER_MSIRDYIE;
|
||
|
break;
|
||
|
case RCC_LSE:
|
||
|
RCC_CIER |= RCC_CIER_LSERDYIE;
|
||
|
break;
|
||
|
case RCC_LSI:
|
||
|
RCC_CIER |= RCC_CIER_LSIRDYIE;
|
||
|
break;
|
||
|
case RCC_HSI48:
|
||
|
RCC_CIER |= RCC_CIER_HSI48RDYIE;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void rcc_osc_ready_int_disable(enum rcc_osc osc)
|
||
|
{
|
||
|
switch (osc) {
|
||
|
case RCC_PLL:
|
||
|
RCC_CIER &= ~RCC_CIER_PLLRDYIE;
|
||
|
break;
|
||
|
case RCC_HSE:
|
||
|
RCC_CIER &= ~RCC_CIER_HSERDYIE;
|
||
|
break;
|
||
|
case RCC_HSI16:
|
||
|
RCC_CIER &= ~RCC_CIER_HSIRDYIE;
|
||
|
break;
|
||
|
case RCC_MSI:
|
||
|
RCC_CIER &= ~RCC_CIER_MSIRDYIE;
|
||
|
break;
|
||
|
case RCC_LSE:
|
||
|
RCC_CIER &= ~RCC_CIER_LSERDYIE;
|
||
|
break;
|
||
|
case RCC_LSI:
|
||
|
RCC_CIER &= ~RCC_CIER_LSIRDYIE;
|
||
|
break;
|
||
|
case RCC_HSI48:
|
||
|
RCC_CIER &= ~RCC_CIER_HSI48RDYIE;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
int rcc_osc_ready_int_flag(enum rcc_osc osc)
|
||
|
{
|
||
|
switch (osc) {
|
||
|
case RCC_PLL:
|
||
|
return ((RCC_CIFR & RCC_CIFR_PLLRDYF) != 0);
|
||
|
break;
|
||
|
case RCC_HSE:
|
||
|
return ((RCC_CIFR & RCC_CIFR_HSERDYF) != 0);
|
||
|
break;
|
||
|
case RCC_HSI16:
|
||
|
return ((RCC_CIFR & RCC_CIFR_HSIRDYF) != 0);
|
||
|
break;
|
||
|
case RCC_MSI:
|
||
|
return ((RCC_CIFR & RCC_CIFR_MSIRDYF) != 0);
|
||
|
break;
|
||
|
case RCC_LSE:
|
||
|
return ((RCC_CIFR & RCC_CIFR_LSERDYF) != 0);
|
||
|
break;
|
||
|
case RCC_LSI:
|
||
|
return ((RCC_CIFR & RCC_CIFR_LSIRDYF) != 0);
|
||
|
break;
|
||
|
case RCC_HSI48:
|
||
|
return ((RCC_CIFR & RCC_CIFR_HSI48RDYF) != 0);
|
||
|
break;
|
||
|
}
|
||
|
return false;
|
||
|
|
||
|
}
|
||
|
|
||
|
void rcc_css_int_clear(void)
|
||
|
{
|
||
|
RCC_CICR |= RCC_CICR_CSSC;
|
||
|
}
|
||
|
|
||
|
int rcc_css_int_flag(void)
|
||
|
{
|
||
|
return ((RCC_CIFR & RCC_CIFR_CSSF) != 0);
|
||
|
}
|
||
|
|
||
|
bool rcc_is_osc_ready(enum rcc_osc osc)
|
||
|
{
|
||
|
switch (osc) {
|
||
|
case RCC_PLL:
|
||
|
return RCC_CR & RCC_CR_PLLRDY;
|
||
|
case RCC_HSE:
|
||
|
return RCC_CR & RCC_CR_HSERDY;
|
||
|
case RCC_HSI16:
|
||
|
return RCC_CR & RCC_CR_HSIRDY;
|
||
|
case RCC_MSI:
|
||
|
return RCC_CR & RCC_CR_MSIRDY;
|
||
|
case RCC_LSE:
|
||
|
return RCC_BDCR & RCC_BDCR_LSERDY;
|
||
|
case RCC_LSI:
|
||
|
return RCC_CSR & RCC_CSR_LSIRDY;
|
||
|
case RCC_HSI48:
|
||
|
return RCC_CRRCR & RCC_CRRCR_HSI48RDY;
|
||
|
}
|
||
|
return false;
|
||
|
}
|
||
|
|
||
|
void rcc_wait_for_osc_ready(enum rcc_osc osc)
|
||
|
{
|
||
|
while (!rcc_is_osc_ready(osc));
|
||
|
}
|
||
|
|
||
|
void rcc_wait_for_sysclk_status(enum rcc_osc osc)
|
||
|
{
|
||
|
switch (osc) {
|
||
|
case RCC_PLL:
|
||
|
while (((RCC_CFGR >> RCC_CFGR_SWS_SHIFT) & RCC_CFGR_SWS_MASK)
|
||
|
!= RCC_CFGR_SWS_PLL);
|
||
|
break;
|
||
|
case RCC_HSE:
|
||
|
while (((RCC_CFGR >> RCC_CFGR_SWS_SHIFT) & RCC_CFGR_SWS_MASK)
|
||
|
!= RCC_CFGR_SWS_HSE);
|
||
|
break;
|
||
|
case RCC_HSI16:
|
||
|
while (((RCC_CFGR >> RCC_CFGR_SWS_SHIFT) & RCC_CFGR_SWS_MASK)
|
||
|
!= RCC_CFGR_SWS_HSI16);
|
||
|
break;
|
||
|
case RCC_MSI:
|
||
|
while (((RCC_CFGR >> RCC_CFGR_SWS_SHIFT) & RCC_CFGR_SWS_MASK)
|
||
|
!= RCC_CFGR_SWS_MSI);
|
||
|
break;
|
||
|
default:
|
||
|
/* Shouldn't be reached. */
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void rcc_osc_on(enum rcc_osc osc)
|
||
|
{
|
||
|
switch (osc) {
|
||
|
case RCC_PLL:
|
||
|
RCC_CR |= RCC_CR_PLLON;
|
||
|
break;
|
||
|
case RCC_HSE:
|
||
|
RCC_CR |= RCC_CR_HSEON;
|
||
|
break;
|
||
|
case RCC_HSI16:
|
||
|
RCC_CR |= RCC_CR_HSION;
|
||
|
break;
|
||
|
case RCC_MSI:
|
||
|
RCC_CR |= RCC_CR_MSION;
|
||
|
break;
|
||
|
case RCC_LSE:
|
||
|
RCC_BDCR |= RCC_BDCR_LSEON;
|
||
|
break;
|
||
|
case RCC_LSI:
|
||
|
RCC_CSR |= RCC_CSR_LSION;
|
||
|
break;
|
||
|
case RCC_HSI48:
|
||
|
RCC_CRRCR |= RCC_CRRCR_HSI48ON;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void rcc_osc_off(enum rcc_osc osc)
|
||
|
{
|
||
|
switch (osc) {
|
||
|
case RCC_PLL:
|
||
|
RCC_CR &= ~RCC_CR_PLLON;
|
||
|
break;
|
||
|
case RCC_HSE:
|
||
|
RCC_CR &= ~RCC_CR_HSEON;
|
||
|
break;
|
||
|
case RCC_HSI16:
|
||
|
RCC_CR &= ~RCC_CR_HSION;
|
||
|
break;
|
||
|
case RCC_MSI:
|
||
|
RCC_CR &= ~RCC_CR_MSION;
|
||
|
break;
|
||
|
case RCC_LSE:
|
||
|
RCC_BDCR &= ~RCC_BDCR_LSEON;
|
||
|
break;
|
||
|
case RCC_LSI:
|
||
|
RCC_CSR &= ~RCC_CSR_LSION;
|
||
|
break;
|
||
|
case RCC_HSI48:
|
||
|
RCC_CRRCR &= ~RCC_CRRCR_HSI48ON;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void rcc_css_enable(void)
|
||
|
{
|
||
|
RCC_CR |= RCC_CR_CSSON;
|
||
|
}
|
||
|
|
||
|
void rcc_css_disable(void)
|
||
|
{
|
||
|
RCC_CR &= ~RCC_CR_CSSON;
|
||
|
}
|
||
|
|
||
|
void rcc_set_sysclk_source(uint32_t clk)
|
||
|
{
|
||
|
uint32_t reg32;
|
||
|
|
||
|
reg32 = RCC_CFGR;
|
||
|
reg32 &= ~(RCC_CFGR_SW_MASK << RCC_CFGR_SW_SHIFT);
|
||
|
RCC_CFGR = (reg32 | (clk << RCC_CFGR_SW_SHIFT));
|
||
|
}
|
||
|
|
||
|
void rcc_set_pll_source(uint32_t pllsrc)
|
||
|
{
|
||
|
uint32_t reg32;
|
||
|
|
||
|
reg32 = RCC_PLLCFGR;
|
||
|
reg32 &= ~(RCC_PLLCFGR_PLLSRC_MASK << RCC_PLLCFGR_PLLSRC_SHIFT);
|
||
|
RCC_PLLCFGR = (reg32 | (pllsrc << RCC_PLLCFGR_PLLSRC_SHIFT));
|
||
|
}
|
||
|
|
||
|
void rcc_set_ppre2(uint32_t ppre2)
|
||
|
{
|
||
|
uint32_t reg32;
|
||
|
|
||
|
reg32 = RCC_CFGR;
|
||
|
reg32 &= ~(RCC_CFGR_PPRE2_MASK << RCC_CFGR_PPRE2_SHIFT);
|
||
|
RCC_CFGR = (reg32 | (ppre2 << RCC_CFGR_PPRE2_SHIFT));
|
||
|
}
|
||
|
|
||
|
void rcc_set_ppre1(uint32_t ppre1)
|
||
|
{
|
||
|
uint32_t reg32;
|
||
|
|
||
|
reg32 = RCC_CFGR;
|
||
|
reg32 &= ~(RCC_CFGR_PPRE1_MASK << RCC_CFGR_PPRE1_SHIFT);
|
||
|
RCC_CFGR = (reg32 | (ppre1 << RCC_CFGR_PPRE1_SHIFT));
|
||
|
}
|
||
|
|
||
|
void rcc_set_hpre(uint32_t hpre)
|
||
|
{
|
||
|
uint32_t reg32;
|
||
|
|
||
|
reg32 = RCC_CFGR;
|
||
|
reg32 &= ~(RCC_CFGR_HPRE_MASK << RCC_CFGR_HPRE_SHIFT);
|
||
|
RCC_CFGR = (reg32 | (hpre << RCC_CFGR_HPRE_SHIFT));
|
||
|
}
|
||
|
|
||
|
void rcc_set_main_pll(uint32_t source, uint32_t pllm, uint32_t plln, uint32_t pllp,
|
||
|
uint32_t pllq, uint32_t pllr)
|
||
|
{
|
||
|
RCC_PLLCFGR = (RCC_PLLCFGR_PLLM(pllm) << RCC_PLLCFGR_PLLM_SHIFT) |
|
||
|
(plln << RCC_PLLCFGR_PLLN_SHIFT) |
|
||
|
(pllp) |
|
||
|
(source << RCC_PLLCFGR_PLLSRC_SHIFT) |
|
||
|
(pllq << RCC_PLLCFGR_PLLQ_SHIFT) |
|
||
|
(pllr << RCC_PLLCFGR_PLLR_SHIFT) | RCC_PLLCFGR_PLLREN;
|
||
|
}
|
||
|
|
||
|
uint32_t rcc_system_clock_source(void)
|
||
|
{
|
||
|
/* Return the clock source which is used as system clock. */
|
||
|
return (RCC_CFGR >> RCC_CFGR_SWS_SHIFT) & RCC_CFGR_SWS_MASK;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Setup clocks to run from PLL.
|
||
|
*
|
||
|
* The arguments provide the pll source, multipliers, dividers, all that's
|
||
|
* needed to establish a system clock.
|
||
|
*
|
||
|
* @param clock clock information structure.
|
||
|
*/
|
||
|
void rcc_clock_setup_pll(const struct rcc_clock_scale *clock)
|
||
|
{
|
||
|
/* Enable internal high-speed oscillator (HSI16). */
|
||
|
rcc_osc_on(RCC_HSI16);
|
||
|
rcc_wait_for_osc_ready(RCC_HSI16);
|
||
|
|
||
|
/* Select HSI16 as SYSCLK source. */
|
||
|
rcc_set_sysclk_source(RCC_PLLCFGR_PLLSRC_HSI16);
|
||
|
|
||
|
/* Enable external high-speed oscillator (HSE). */
|
||
|
if (clock->pll_source == RCC_PLLCFGR_PLLSRC_HSE) {
|
||
|
rcc_osc_on(RCC_HSE);
|
||
|
rcc_wait_for_osc_ready(RCC_HSE);
|
||
|
}
|
||
|
|
||
|
/* Set the VOS scale mode */
|
||
|
rcc_periph_clock_enable(RCC_PWR);
|
||
|
pwr_set_vos_scale(clock->voltage_scale);
|
||
|
|
||
|
/*
|
||
|
* Set prescalers for AHB, ADC, APB1, APB2.
|
||
|
* Do this before touching the PLL (TODO: why?).
|
||
|
*/
|
||
|
rcc_set_hpre(clock->hpre);
|
||
|
rcc_set_ppre1(clock->ppre1);
|
||
|
rcc_set_ppre2(clock->ppre2);
|
||
|
|
||
|
/* Disable PLL oscillator before changing its configuration. */
|
||
|
rcc_osc_off(RCC_PLL);
|
||
|
|
||
|
/* Configure the PLL oscillator. */
|
||
|
rcc_set_main_pll(clock->pll_source, clock->pllm, clock->plln,
|
||
|
clock->pllp, clock->pllq, clock->pllr);
|
||
|
|
||
|
/* Enable PLL oscillator and wait for it to stabilize. */
|
||
|
rcc_osc_on(RCC_PLL);
|
||
|
rcc_wait_for_osc_ready(RCC_PLL);
|
||
|
|
||
|
/* Configure flash settings. */
|
||
|
if (clock->flash_config & FLASH_ACR_DCEN) {
|
||
|
flash_dcache_enable();
|
||
|
} else {
|
||
|
flash_dcache_disable();
|
||
|
}
|
||
|
if (clock->flash_config & FLASH_ACR_ICEN) {
|
||
|
flash_icache_enable();
|
||
|
} else {
|
||
|
flash_icache_disable();
|
||
|
}
|
||
|
flash_set_ws(clock->flash_config);
|
||
|
|
||
|
/* Select PLL as SYSCLK source. */
|
||
|
rcc_set_sysclk_source(RCC_CFGR_SW_PLL);
|
||
|
|
||
|
/* Wait for PLL clock to be selected. */
|
||
|
rcc_wait_for_sysclk_status(RCC_PLL);
|
||
|
|
||
|
/* Set the peripheral clock frequencies used. */
|
||
|
rcc_ahb_frequency = clock->ahb_frequency;
|
||
|
rcc_apb1_frequency = clock->apb1_frequency;
|
||
|
rcc_apb2_frequency = clock->apb2_frequency;
|
||
|
|
||
|
/* Disable internal high-speed oscillator. */
|
||
|
if (clock->pll_source == RCC_PLLCFGR_PLLSRC_HSE) {
|
||
|
rcc_osc_off(RCC_HSI16);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Set the msi run time range.
|
||
|
* Can only be called when MSI is either OFF, or when MSI is on _and_
|
||
|
* ready. (RCC_CR_MSIRDY bit). @sa rcc_set_msi_range_standby
|
||
|
* @param msi_range range number @ref rcc_cr_msirange
|
||
|
*/
|
||
|
void rcc_set_msi_range(uint32_t msi_range)
|
||
|
{
|
||
|
uint32_t reg = RCC_CR;
|
||
|
reg &= ~(RCC_CR_MSIRANGE_MASK << RCC_CR_MSIRANGE_SHIFT);
|
||
|
reg |= msi_range << RCC_CR_MSIRANGE_SHIFT;
|
||
|
RCC_CR = reg | RCC_CR_MSIRGSEL;
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Set the msi range after reset/standby.
|
||
|
* Until MSIRGSEl bit is set, this defines the MSI range.
|
||
|
* Note that not all MSI range values are allowed here!
|
||
|
* @sa rcc_set_msi_range
|
||
|
* @param msi_range range number valid for post standby @ref rcc_csr_msirange
|
||
|
*/
|
||
|
void rcc_set_msi_range_standby(uint32_t msi_range)
|
||
|
{
|
||
|
uint32_t reg = RCC_CSR;
|
||
|
reg &= ~(RCC_CSR_MSIRANGE_MASK << RCC_CSR_MSIRANGE_SHIFT);
|
||
|
reg |= msi_range << RCC_CSR_MSIRANGE_SHIFT;
|
||
|
RCC_CSR = reg;
|
||
|
}
|
||
|
|
||
|
/** Enable PLL Output
|
||
|
*
|
||
|
* - P (RCC_PLLCFGR_PLLPEN)
|
||
|
* - Q (RCC_PLLCFGR_PLLQEN)
|
||
|
* - R (RCC_PLLCFGR_PLLREN)
|
||
|
*
|
||
|
* @param pllout One or more of the definitions above
|
||
|
*/
|
||
|
void rcc_pll_output_enable(uint32_t pllout)
|
||
|
{
|
||
|
RCC_PLLCFGR |= pllout;
|
||
|
}
|
||
|
|
||
|
/** Set clock source for 48MHz clock
|
||
|
*
|
||
|
* The 48 MHz clock is derived from one of the four following sources:
|
||
|
* - main PLL VCO (RCC_CCIPR_CLK48SEL_PLL)
|
||
|
* - PLLSAI1 VCO (RCC_CCIPR_CLK48SEL_PLLSAI1Q)
|
||
|
* - MSI clock (RCC_CCIPR_CLK48SEL_MSI)
|
||
|
* - HSI48 internal oscillator (RCC_CCIPR_CLK48SEL_HSI48)
|
||
|
*
|
||
|
* @param clksel One of the definitions above
|
||
|
*/
|
||
|
void rcc_set_clock48_source(uint32_t clksel)
|
||
|
{
|
||
|
RCC_CCIPR &= ~(RCC_CCIPR_CLK48SEL_MASK << RCC_CCIPR_CLK48SEL_SHIFT);
|
||
|
RCC_CCIPR |= (clksel << RCC_CCIPR_CLK48SEL_SHIFT);
|
||
|
}
|
||
|
|
||
|
|
||
|
/** Enable the RTC clock */
|
||
|
void rcc_enable_rtc_clock(void)
|
||
|
{
|
||
|
RCC_BDCR |= RCC_BDCR_RTCEN;
|
||
|
}
|
||
|
|
||
|
/** Disable the RTC clock */
|
||
|
void rcc_disable_rtc_clock(void)
|
||
|
{
|
||
|
RCC_BDCR &= ~RCC_BDCR_RTCEN;
|
||
|
}
|
||
|
|
||
|
/** Set the source for the RTC clock
|
||
|
* @param[in] clk ::rcc_osc. RTC clock source. Only HSE/32, LSE and LSI.
|
||
|
*/
|
||
|
void rcc_set_rtc_clock_source(enum rcc_osc clk)
|
||
|
{
|
||
|
RCC_BDCR &= ~(RCC_BDCR_RTCSEL_MASK << RCC_BDCR_RTCSEL_SHIFT);
|
||
|
|
||
|
switch (clk) {
|
||
|
case RCC_HSE:
|
||
|
RCC_BDCR |= (RCC_BDCR_RTCSEL_HSEDIV32 << RCC_BDCR_RTCSEL_SHIFT);
|
||
|
break;
|
||
|
case RCC_LSE:
|
||
|
RCC_BDCR |= (RCC_BDCR_RTCSEL_LSE << RCC_BDCR_RTCSEL_SHIFT);
|
||
|
break;
|
||
|
case RCC_LSI:
|
||
|
RCC_BDCR |= (RCC_BDCR_RTCSEL_LSI << RCC_BDCR_RTCSEL_SHIFT);
|
||
|
break;
|
||
|
default:
|
||
|
/* none selected */
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* Helper to calculate the frequency of a UART/I2C based on the apb and clksel value.
|
||
|
* For I2C, clock selection 0b11 is reserved while it specifies LSE for UARTs. */
|
||
|
static uint32_t rcc_uart_i2c_clksel_freq_hz(uint32_t apb_clk, uint8_t shift, uint32_t clock_reg) {
|
||
|
uint8_t clksel = (clock_reg >> shift) & RCC_CCIPR_USARTxSEL_MASK;
|
||
|
uint8_t hpre = (RCC_CFGR >> RCC_CFGR_HPRE_SHIFT) & RCC_CFGR_HPRE_MASK;
|
||
|
switch (clksel) {
|
||
|
case RCC_CCIPR_USARTxSEL_APB:
|
||
|
return apb_clk;
|
||
|
case RCC_CCIPR_USARTxSEL_SYS:
|
||
|
return rcc_ahb_frequency * rcc_get_div_from_hpre(hpre);
|
||
|
case RCC_CCIPR_USARTxSEL_HSI16:
|
||
|
return 16000000U;
|
||
|
case RCC_CCIPR_USARTxSEL_LSE:
|
||
|
return 32768U;
|
||
|
}
|
||
|
cm3_assert_not_reached();
|
||
|
}
|
||
|
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
/** @brief Get the peripheral clock speed for the USART at base specified.
|
||
|
* @param usart Base address of USART to get clock frequency for.
|
||
|
*/
|
||
|
uint32_t rcc_get_usart_clk_freq(uint32_t usart)
|
||
|
{
|
||
|
/* Handle values with selectable clocks. */
|
||
|
if (usart == LPUART1_BASE) {
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_LPUART1SEL_SHIFT, RCC_CCIPR);
|
||
|
} else if (usart == USART1_BASE) {
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb2_frequency, RCC_CCIPR_USART1SEL_SHIFT, RCC_CCIPR);
|
||
|
} else if (usart == USART2_BASE) {
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_USART2SEL_SHIFT, RCC_CCIPR);
|
||
|
} else if (usart == USART3_BASE) {
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_USART3SEL_SHIFT, RCC_CCIPR);
|
||
|
} else if (usart == UART4_BASE) {
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_UART4SEL_SHIFT, RCC_CCIPR);
|
||
|
} else { /* USART5 */
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_UART5SEL_SHIFT, RCC_CCIPR);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
/** @brief Get the peripheral clock speed for the Timer at base specified.
|
||
|
* @param timer Base address of TIM to get clock frequency for.
|
||
|
*/
|
||
|
uint32_t rcc_get_timer_clk_freq(uint32_t timer)
|
||
|
{
|
||
|
/* Handle APB1 timers, and apply multiplier if necessary. */
|
||
|
if (timer == LPTIM1_BASE || timer == LPTIM2_BASE) {
|
||
|
int shift = (timer == LPTIM1_BASE) ? RCC_CCIPR_LPTIM1SEL_SHIFT : RCC_CCIPR_LPTIM2SEL_SHIFT;
|
||
|
uint8_t clksel = (RCC_CCIPR >> shift) & RCC_CCIPR_LPTIMxSEL_MASK;
|
||
|
switch (clksel) {
|
||
|
case RCC_CCIPR_LPTIMxSEL_APB:
|
||
|
return rcc_apb1_frequency;
|
||
|
case RCC_CCIPR_LPTIMxSEL_LSI:
|
||
|
return 32000U;
|
||
|
case RCC_CCIPR_LPTIMxSEL_HSI16:
|
||
|
return 16000000U;
|
||
|
case RCC_CCIPR_LPTIMxSEL_LSE:
|
||
|
return 32768U;
|
||
|
}
|
||
|
} else if (timer >= TIM2_BASE && timer <= TIM7_BASE) {
|
||
|
uint8_t ppre1 = (RCC_CFGR >> RCC_CFGR_PPRE1_SHIFT) & RCC_CFGR_PPRE1_MASK;
|
||
|
return (ppre1 == RCC_CFGR_PPRE_NODIV) ? rcc_apb1_frequency
|
||
|
: 2 * rcc_apb1_frequency;
|
||
|
} else {
|
||
|
uint8_t ppre2 = (RCC_CFGR >> RCC_CFGR_PPRE2_SHIFT) & RCC_CFGR_PPRE2_MASK;
|
||
|
return (ppre2 == RCC_CFGR_PPRE_NODIV) ? rcc_apb2_frequency
|
||
|
: 2 * rcc_apb2_frequency;
|
||
|
}
|
||
|
cm3_assert_not_reached();
|
||
|
}
|
||
|
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
/** @brief Get the peripheral clock speed for the I2C device at base specified.
|
||
|
* @param i2c Base address of I2C to get clock frequency for.
|
||
|
*/
|
||
|
uint32_t rcc_get_i2c_clk_freq(uint32_t i2c)
|
||
|
{
|
||
|
if (i2c == I2C1_BASE) {
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_I2C1SEL_SHIFT, RCC_CCIPR);
|
||
|
} else if (i2c == I2C2_BASE) {
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_I2C2SEL_SHIFT, RCC_CCIPR);
|
||
|
} else if (i2c == I2C3_BASE) {
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_I2C3SEL_SHIFT, RCC_CCIPR);
|
||
|
} else { /* I2C4 */
|
||
|
return rcc_uart_i2c_clksel_freq_hz(rcc_apb1_frequency, RCC_CCIPR_I2C4SEL_SHIFT, RCC_CCIPR2);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/*---------------------------------------------------------------------------*/
|
||
|
/** @brief Get the peripheral clock speed for the SPI device at base specified.
|
||
|
* @param spi Base address of SPI device to get clock frequency for (e.g. SPI1_BASE).
|
||
|
*/
|
||
|
uint32_t rcc_get_spi_clk_freq(uint32_t spi) {
|
||
|
if (spi == SPI1_BASE) {
|
||
|
return rcc_apb2_frequency;
|
||
|
} else {
|
||
|
return rcc_apb1_frequency;
|
||
|
}
|
||
|
}
|
||
|
/**@}*/
|