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libopencm3/lib/stm32/f4/rcc.c

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/** @defgroup rcc_file RCC peripheral API
*
* @ingroup peripheral_apis
*
* @section rcc_f4_api_ex Reset and Clock Control API.
*
* @brief <b>libopencm3 STM32F4xx Reset and Clock Control</b>
*
* @author @htmlonly &copy; @endhtmlonly 2013 Frantisek Burian <BuFran at seznam.cz>
*
* @date 18 Jun 2013
*
* 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) 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/pwr.h>
#include <libopencm3/stm32/flash.h>
/**@{*/
/* Set the default clock frequencies after reset. */
uint32_t rcc_ahb_frequency = 16000000;
uint32_t rcc_apb1_frequency = 16000000;
uint32_t rcc_apb2_frequency = 16000000;
const struct rcc_clock_scale rcc_hsi_configs[RCC_CLOCK_3V3_END] = {
{ /* 84MHz */
.pllm = 16,
.plln = 336,
.pllp = 4,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSI_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV2,
.ppre2 = RCC_CFGR_PPRE_NODIV,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_2WS,
.ahb_frequency = 84000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 168MHz */
.pllm = 16,
.plln = 336,
.pllp = 2,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSI_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 168000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 180MHz */
.pllm = 16,
.plln = 360,
.pllp = 2,
.pllq = 8,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSI_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 180000000,
.apb1_frequency = 45000000,
.apb2_frequency = 90000000,
},
};
const struct rcc_clock_scale rcc_hse_8mhz_3v3[RCC_CLOCK_3V3_END] = {
{ /* 84MHz */
.pllm = 8,
.plln = 336,
.pllp = 4,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV2,
.ppre2 = RCC_CFGR_PPRE_NODIV,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_2WS,
.ahb_frequency = 84000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 168MHz */
.pllm = 8,
.plln = 336,
.pllp = 2,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 168000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 180MHz */
.pllm = 8,
.plln = 360,
.pllp = 2,
.pllq = 8,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 180000000,
.apb1_frequency = 45000000,
.apb2_frequency = 90000000,
},
};
const struct rcc_clock_scale rcc_hse_12mhz_3v3[RCC_CLOCK_3V3_END] = {
{ /* 84MHz */
.pllm = 12,
.plln = 336,
.pllp = 4,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV2,
.ppre2 = RCC_CFGR_PPRE_NODIV,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_2WS,
.ahb_frequency = 84000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 168MHz */
.pllm = 12,
.plln = 336,
.pllp = 2,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 168000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 180MHz */
.pllm = 12,
.plln = 360,
.pllp = 2,
.pllq = 8,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 180000000,
.apb1_frequency = 45000000,
.apb2_frequency = 90000000,
},
};
const struct rcc_clock_scale rcc_hse_16mhz_3v3[RCC_CLOCK_3V3_END] = {
{ /* 84MHz */
.pllm = 16,
.plln = 336,
.pllp = 4,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV2,
.ppre2 = RCC_CFGR_PPRE_NODIV,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_2WS,
.ahb_frequency = 84000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 168MHz */
.pllm = 16,
.plln = 336,
.pllp = 2,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 168000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 180MHz */
.pllm = 16,
.plln = 360,
.pllp = 2,
.pllq = 8,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 180000000,
.apb1_frequency = 45000000,
.apb2_frequency = 90000000,
},
};
const struct rcc_clock_scale rcc_hse_25mhz_3v3[RCC_CLOCK_3V3_END] = {
{ /* 84MHz */
.pllm = 25,
.plln = 336,
.pllp = 4,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV2,
.ppre2 = RCC_CFGR_PPRE_NODIV,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_2WS,
.ahb_frequency = 84000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 168MHz */
.pllm = 25,
.plln = 336,
.pllp = 2,
.pllq = 7,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 168000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 180MHz */
.pllm = 25,
.plln = 360,
.pllp = 2,
.pllq = 8,
.pllr = 0,
.pll_source = RCC_CFGR_PLLSRC_HSE_CLK,
.hpre = RCC_CFGR_HPRE_NODIV,
.ppre1 = RCC_CFGR_PPRE_DIV4,
.ppre2 = RCC_CFGR_PPRE_DIV2,
.voltage_scale = PWR_SCALE1,
.flash_config = FLASH_ACR_DCEN | FLASH_ACR_ICEN |
FLASH_ACR_LATENCY_5WS,
.ahb_frequency = 180000000,
.apb1_frequency = 45000000,
.apb2_frequency = 90000000,
},
};
void rcc_osc_ready_int_clear(enum rcc_osc osc)
{
switch (osc) {
case RCC_PLL:
RCC_CIR |= RCC_CIR_PLLRDYC;
break;
case RCC_HSE:
RCC_CIR |= RCC_CIR_HSERDYC;
break;
case RCC_HSI:
RCC_CIR |= RCC_CIR_HSIRDYC;
break;
case RCC_LSE:
RCC_CIR |= RCC_CIR_LSERDYC;
break;
case RCC_LSI:
RCC_CIR |= RCC_CIR_LSIRDYC;
break;
case RCC_PLLSAI:
RCC_CIR |= RCC_CIR_PLLSAIRDYC;
break;
case RCC_PLLI2S:
RCC_CIR |= RCC_CIR_PLLI2SRDYC;
break;
}
}
void rcc_osc_ready_int_enable(enum rcc_osc osc)
{
switch (osc) {
case RCC_PLL:
RCC_CIR |= RCC_CIR_PLLRDYIE;
break;
case RCC_HSE:
RCC_CIR |= RCC_CIR_HSERDYIE;
break;
case RCC_HSI:
RCC_CIR |= RCC_CIR_HSIRDYIE;
break;
case RCC_LSE:
RCC_CIR |= RCC_CIR_LSERDYIE;
break;
case RCC_LSI:
RCC_CIR |= RCC_CIR_LSIRDYIE;
break;
case RCC_PLLSAI:
RCC_CIR |= RCC_CIR_PLLSAIRDYIE;
break;
case RCC_PLLI2S:
RCC_CIR |= RCC_CIR_PLLI2SRDYIE;
break;
}
}
void rcc_osc_ready_int_disable(enum rcc_osc osc)
{
switch (osc) {
case RCC_PLL:
RCC_CIR &= ~RCC_CIR_PLLRDYIE;
break;
case RCC_HSE:
RCC_CIR &= ~RCC_CIR_HSERDYIE;
break;
case RCC_HSI:
RCC_CIR &= ~RCC_CIR_HSIRDYIE;
break;
case RCC_LSE:
RCC_CIR &= ~RCC_CIR_LSERDYIE;
break;
case RCC_LSI:
RCC_CIR &= ~RCC_CIR_LSIRDYIE;
break;
case RCC_PLLSAI:
RCC_CIR &= ~RCC_CIR_PLLSAIRDYIE;
break;
case RCC_PLLI2S:
RCC_CIR &= ~RCC_CIR_PLLI2SRDYIE;
break;
}
}
int rcc_osc_ready_int_flag(enum rcc_osc osc)
{
switch (osc) {
case RCC_PLL:
return ((RCC_CIR & RCC_CIR_PLLRDYF) != 0);
case RCC_HSE:
return ((RCC_CIR & RCC_CIR_HSERDYF) != 0);
case RCC_HSI:
return ((RCC_CIR & RCC_CIR_HSIRDYF) != 0);
case RCC_LSE:
return ((RCC_CIR & RCC_CIR_LSERDYF) != 0);
case RCC_LSI:
return ((RCC_CIR & RCC_CIR_LSIRDYF) != 0);
case RCC_PLLSAI:
return ((RCC_CIR & RCC_CIR_PLLSAIRDYF) != 0);
case RCC_PLLI2S:
return ((RCC_CIR & RCC_CIR_PLLI2SRDYF) != 0);
}
return 0;
}
void rcc_css_int_clear(void)
{
RCC_CIR |= RCC_CIR_CSSC;
}
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_PLL:
return RCC_CR & RCC_CR_PLLRDY;
case RCC_HSE:
return RCC_CR & RCC_CR_HSERDY;
case RCC_HSI:
return RCC_CR & RCC_CR_HSIRDY;
case RCC_LSE:
return RCC_BDCR & RCC_BDCR_LSERDY;
case RCC_LSI:
return RCC_CSR & RCC_CSR_LSIRDY;
case RCC_PLLSAI:
return RCC_CR & RCC_CR_PLLSAIRDY;
case RCC_PLLI2S:
return RCC_CR & RCC_CR_PLLI2SRDY;
}
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_HSI:
while (((RCC_CFGR >> RCC_CFGR_SWS_SHIFT) & RCC_CFGR_SWS_MASK) !=
RCC_CFGR_SWS_HSI);
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_HSI:
RCC_CR |= RCC_CR_HSION;
break;
case RCC_LSE:
RCC_BDCR |= RCC_BDCR_LSEON;
break;
case RCC_LSI:
RCC_CSR |= RCC_CSR_LSION;
break;
case RCC_PLLSAI:
RCC_CR |= RCC_CR_PLLSAION;
break;
case RCC_PLLI2S:
RCC_CR |= RCC_CR_PLLI2SON;
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_HSI:
RCC_CR &= ~RCC_CR_HSION;
break;
case RCC_LSE:
RCC_BDCR &= ~RCC_BDCR_LSEON;
break;
case RCC_LSI:
RCC_CSR &= ~RCC_CSR_LSION;
break;
case RCC_PLLSAI:
RCC_CR &= ~RCC_CR_PLLSAION;
break;
case RCC_PLLI2S:
RCC_CR &= ~RCC_CR_PLLI2SON;
break;
}
}
void rcc_css_enable(void)
{
RCC_CR |= RCC_CR_CSSON;
}
void rcc_css_disable(void)
{
RCC_CR &= ~RCC_CR_CSSON;
}
/**
* Set the dividers for the PLLI2S clock outputs
* @param n valid range depends on target device, check your RefManual.
* @param r valid range is 2..7
*/
void rcc_plli2s_config(uint16_t n, uint8_t r)
{
RCC_PLLI2SCFGR = (
((n & RCC_PLLI2SCFGR_PLLI2SN_MASK) << RCC_PLLI2SCFGR_PLLI2SN_SHIFT) |
((r & RCC_PLLI2SCFGR_PLLI2SR_MASK) << RCC_PLLI2SCFGR_PLLI2SR_SHIFT));
}
/**
* Set the dividers for the PLLSAI clock outputs
* divider p is only available on F4x9 parts, pass 0 for other parts.
* @param n valid range is 49..432
* @param p 0 if unused, @ref rcc_pllsaicfgr_pllsaip
* @param q valid range is 2..15
* @param r valid range is 2..7
* @sa rcc_pllsai_postscalers
*/
void rcc_pllsai_config(uint16_t n, uint16_t p, uint16_t q, uint16_t r)
{
RCC_PLLSAICFGR = (
((n & RCC_PLLSAICFGR_PLLSAIN_MASK) << RCC_PLLSAICFGR_PLLSAIN_SHIFT) |
((p & RCC_PLLSAICFGR_PLLSAIP_MASK) << RCC_PLLSAICFGR_PLLSAIP_SHIFT) |
((q & RCC_PLLSAICFGR_PLLSAIQ_MASK) << RCC_PLLSAICFGR_PLLSAIQ_SHIFT) |
((r & RCC_PLLSAICFGR_PLLSAIR_MASK) << RCC_PLLSAICFGR_PLLSAIR_SHIFT));
}
/**
* Set the dedicated dividers after the PLLSAI configuration.
*
* @param q dedicated PLLSAI divider, for either A or B
* @param r dedicated LCD-TFT divider, see LTDC
* @sa rcc_pllsai_config
*/
void rcc_pllsai_postscalers(uint8_t q, uint8_t r)
{
uint32_t reg32 = RCC_DCKCFGR;
reg32 &= ((RCC_DCKCFGR_PLLSAIDIVR_MASK << RCC_DCKCFGR_PLLSAIDIVR_SHIFT)
| (RCC_DCKCFGR_PLLSAIDIVQ_MASK << RCC_DCKCFGR_PLLSAIDIVQ_SHIFT));
RCC_DCKCFGR = reg32 | ((q << RCC_DCKCFGR_PLLSAIDIVQ_SHIFT) |
(r << RCC_DCKCFGR_PLLSAIDIVR_SHIFT));
}
void rcc_set_sysclk_source(uint32_t clk)
{
uint32_t reg32;
reg32 = RCC_CFGR;
reg32 &= ~((1 << 1) | (1 << 0));
RCC_CFGR = (reg32 | clk);
}
void rcc_set_pll_source(uint32_t pllsrc)
{
uint32_t reg32;
reg32 = RCC_PLLCFGR;
reg32 &= ~(1 << 22);
RCC_PLLCFGR = (reg32 | (pllsrc << 22));
}
void rcc_set_ppre2(uint32_t ppre2)
{
uint32_t reg32;
reg32 = RCC_CFGR;
reg32 &= ~((1 << 13) | (1 << 14) | (1 << 15));
RCC_CFGR = (reg32 | (ppre2 << 13));
}
void rcc_set_ppre1(uint32_t ppre1)
{
uint32_t reg32;
reg32 = RCC_CFGR;
reg32 &= ~((1 << 10) | (1 << 11) | (1 << 12));
RCC_CFGR = (reg32 | (ppre1 << 10));
}
void rcc_set_hpre(uint32_t hpre)
{
uint32_t reg32;
reg32 = RCC_CFGR;
reg32 &= ~((1 << 4) | (1 << 5) | (1 << 6) | (1 << 7));
RCC_CFGR = (reg32 | (hpre << 4));
}
void rcc_set_rtcpre(uint32_t rtcpre)
{
uint32_t reg32;
reg32 = RCC_CFGR;
reg32 &= ~((1 << 16) | (1 << 17) | (1 << 18) | (1 << 19) | (1 << 20));
RCC_CFGR = (reg32 | (rtcpre << 16));
}
/**
* Reconfigures the main PLL for a HSI source.
* Any reserved bits are kept at their reset values.
* @param pllm Divider for the main PLL input clock
* @param plln Main PLL multiplication factor for VCO
* @param pllp Main PLL divider for main system clock
* @param pllq Main PLL divider for USB OTG FS, SDMMC & RNG
* @param pllr Main PLL divider for DSI (for parts without DSI, provide 0 here)
*/
void rcc_set_main_pll_hsi(uint32_t pllm, uint32_t plln, uint32_t pllp,
uint32_t pllq, uint32_t pllr)
{
/* Use reset value if not legal, for parts without pllr */
if (pllr < 2) {
pllr = 2;
}
RCC_PLLCFGR = 0 | /* HSI */
((pllm & RCC_PLLCFGR_PLLM_MASK) << RCC_PLLCFGR_PLLM_SHIFT) |
((plln & RCC_PLLCFGR_PLLN_MASK) << RCC_PLLCFGR_PLLN_SHIFT) |
((((pllp >> 1) - 1) & RCC_PLLCFGR_PLLP_MASK) << RCC_PLLCFGR_PLLP_SHIFT) |
((pllq & RCC_PLLCFGR_PLLQ_MASK) << RCC_PLLCFGR_PLLQ_SHIFT) |
((pllr & RCC_PLLCFGR_PLLR_MASK) << RCC_PLLCFGR_PLLR_SHIFT);
}
/**
* Reconfigures the main PLL for a HSE source.
* Any reserved bits are kept at their reset values.
* @param pllm Divider for the main PLL input clock
* @param plln Main PLL multiplication factor for VCO
* @param pllp Main PLL divider for main system clock
* @param pllq Main PLL divider for USB OTG FS, SDMMC & RNG
* @param pllr Main PLL divider for DSI (for parts without DSI, provide 0 here)
*/
void rcc_set_main_pll_hse(uint32_t pllm, uint32_t plln, uint32_t pllp,
uint32_t pllq, uint32_t pllr)
{
/* Use reset value if not legal, for parts without pllr */
if (pllr < 2) {
pllr = 2;
}
RCC_PLLCFGR = RCC_PLLCFGR_PLLSRC | /* HSE */
((pllm & RCC_PLLCFGR_PLLM_MASK) << RCC_PLLCFGR_PLLM_SHIFT) |
((plln & RCC_PLLCFGR_PLLN_MASK) << RCC_PLLCFGR_PLLN_SHIFT) |
((((pllp >> 1) - 1) & RCC_PLLCFGR_PLLP_MASK) << RCC_PLLCFGR_PLLP_SHIFT) |
((pllq & RCC_PLLCFGR_PLLQ_MASK) << RCC_PLLCFGR_PLLQ_SHIFT) |
((pllr & RCC_PLLCFGR_PLLR_MASK) << RCC_PLLCFGR_PLLR_SHIFT);
}
uint32_t rcc_system_clock_source(void)
{
/* Return the clock source which is used as system clock. */
return (RCC_CFGR & 0x000c) >> 2;
}
/**
* 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 (HSI). */
rcc_osc_on(RCC_HSI);
rcc_wait_for_osc_ready(RCC_HSI);
/* Select HSI as SYSCLK source. */
rcc_set_sysclk_source(RCC_CFGR_SW_HSI);
/* Enable external high-speed oscillator (HSE). */
if (clock->pll_source == RCC_CFGR_PLLSRC_HSE_CLK) {
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. */
if (clock->pll_source == RCC_CFGR_PLLSRC_HSE_CLK) {
rcc_set_main_pll_hse(clock->pllm, clock->plln,
clock->pllp, clock->pllq, clock->pllr);
} else {
rcc_set_main_pll_hsi(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_CFGR_PLLSRC_HSE_CLK) {
rcc_osc_off(RCC_HSI);
}
}
/**
* Setup clocks with the HSE.
*
* @deprecated replaced by rcc_clock_setup_pll as a drop in replacement.
* @see rcc_clock_setup_pll which supports HSI as well as HSE, using the same
* clock structures.
*/
void rcc_clock_setup_hse_3v3(const struct rcc_clock_scale *clock)
{
rcc_clock_setup_pll(clock);
}
/*---------------------------------------------------------------------------*/
/** @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 == USART1_BASE || usart == USART6_BASE) {
return rcc_apb2_frequency;
} else {
return rcc_apb1_frequency;
}
}
/*---------------------------------------------------------------------------*/
/** @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 timer clocks. */
if (timer >= TIM2_BASE && timer <= TIM14_BASE) {
uint8_t ppre1 = (RCC_CFGR >> RCC_CFGR_PPRE1_SHIFT) & RCC_CFGR_PPRE1_MASK;
return (ppre1 == RCC_CFGR_PPRE_DIV_NONE) ? 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_DIV_NONE) ? rcc_apb2_frequency
: 2 * rcc_apb2_frequency;
}
}
/*---------------------------------------------------------------------------*/
/** @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 __attribute__((unused)))
{
return rcc_apb1_frequency;
}
/*---------------------------------------------------------------------------*/
/** @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 == SPI2_BASE || spi == SPI3_BASE) {
return rcc_apb1_frequency;
} else {
return rcc_apb2_frequency;
}
}
/**@}*/
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