diff options
Diffstat (limited to 'libopencm3/lib/stm32/f0/rcc.c')
| -rw-r--r-- | libopencm3/lib/stm32/f0/rcc.c | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/libopencm3/lib/stm32/f0/rcc.c b/libopencm3/lib/stm32/f0/rcc.c new file mode 100644 index 0000000..1f37133 --- /dev/null +++ b/libopencm3/lib/stm32/f0/rcc.c @@ -0,0 +1,665 @@ +/** @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> + +uint32_t rcc_core_frequency = 8000000; /* 8MHz after reset */ +uint32_t rcc_ppre_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 HSI48: + RCC_CIR |= RCC_CIR_HSI48RDYC; + break; + case HSI14: + RCC_CIR |= RCC_CIR_HSI14RDYC; + break; + case HSI: + RCC_CIR |= RCC_CIR_HSIRDYC; + break; + case HSE: + RCC_CIR |= RCC_CIR_HSERDYC; + break; + case PLL: + RCC_CIR |= RCC_CIR_PLLRDYC; + break; + case LSE: + RCC_CIR |= RCC_CIR_LSERDYC; + break; + case 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 HSI48: + RCC_CIR |= RCC_CIR_HSI48RDYIE; + break; + case HSI14: + RCC_CIR |= RCC_CIR_HSI14RDYIE; + break; + case HSI: + RCC_CIR |= RCC_CIR_HSIRDYIE; + break; + case HSE: + RCC_CIR |= RCC_CIR_HSERDYIE; + break; + case PLL: + RCC_CIR |= RCC_CIR_PLLRDYIE; + break; + case LSE: + RCC_CIR |= RCC_CIR_LSERDYIE; + break; + case 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 HSI48: + RCC_CIR &= ~RCC_CIR_HSI48RDYC; + break; + case HSI14: + RCC_CIR &= ~RCC_CIR_HSI14RDYC; + break; + case HSI: + RCC_CIR &= ~RCC_CIR_HSIRDYC; + break; + case HSE: + RCC_CIR &= ~RCC_CIR_HSERDYC; + break; + case PLL: + RCC_CIR &= ~RCC_CIR_PLLRDYC; + break; + case LSE: + RCC_CIR &= ~RCC_CIR_LSERDYC; + break; + case 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 HSI48: + return (RCC_CIR & RCC_CIR_HSI48RDYF) != 0; + break; + case HSI14: + return (RCC_CIR & RCC_CIR_HSI14RDYF) != 0; + break; + case HSI: + return (RCC_CIR & RCC_CIR_HSIRDYF) != 0; + break; + case HSE: + return (RCC_CIR & RCC_CIR_HSERDYF) != 0; + break; + case PLL: + return (RCC_CIR & RCC_CIR_PLLRDYF) != 0; + break; + case LSE: + return (RCC_CIR & RCC_CIR_LSERDYF) != 0; + break; + case 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); +} + +/*---------------------------------------------------------------------------*/ +/** @brief RCC Wait for Oscillator Ready. + * + * @param[in] osc enum ::osc_t. Oscillator ID + */ + +void rcc_wait_for_osc_ready(enum rcc_osc osc) +{ + switch (osc) { + case HSI48: + while ((RCC_CIR & RCC_CIR_HSI48RDYF) != 0); + break; + case HSI14: + while ((RCC_CIR & RCC_CIR_HSI14RDYF) != 0); + break; + case HSI: + while ((RCC_CIR & RCC_CIR_HSIRDYF) != 0); + break; + case HSE: + while ((RCC_CIR & RCC_CIR_HSERDYF) != 0); + break; + case PLL: + while ((RCC_CIR & RCC_CIR_PLLRDYF) != 0); + break; + case LSE: + while ((RCC_CIR & RCC_CIR_LSERDYF) != 0); + break; + case LSI: + while ((RCC_CIR & RCC_CIR_LSIRDYF) != 0); + break; + } +} + +/*---------------------------------------------------------------------------*/ +/** @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 HSI48: + RCC_CR2 |= RCC_CR2_HSI48ON; + break; + case HSI14: + RCC_CR2 |= RCC_CR2_HSI14ON; + break; + case HSI: + RCC_CR |= RCC_CR_HSION; + break; + case HSE: + RCC_CR |= RCC_CR_HSEON; + break; + case LSE: + RCC_BDCR |= RCC_BDCR_LSEON; + break; + case LSI: + RCC_CSR |= RCC_CSR_LSION; + break; + case 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 HSI48: + RCC_CR2 &= ~RCC_CR2_HSI48ON; + break; + case HSI14: + RCC_CR2 &= ~RCC_CR2_HSI14ON; + break; + case HSI: + RCC_CR &= ~RCC_CR_HSION; + break; + case HSE: + RCC_CR &= ~RCC_CR_HSEON; + break; + case LSE: + RCC_BDCR &= ~RCC_BDCR_LSEON; + break; + case LSI: + RCC_CSR &= ~RCC_CSR_LSION; + break; + case 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 HSE: + RCC_CR |= RCC_CR_HSEBYP; + break; + case LSE: + RCC_BDCR |= RCC_BDCR_LSEBYP; + break; + case HSI48: + case HSI14: + case HSI: + case LSI: + case 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 HSE: + RCC_CR &= ~RCC_CR_HSEBYP; + break; + case LSE: + RCC_BDCR &= ~RCC_BDCR_LSEBYP; + break; + case HSI48: + case HSI14: + case PLL: + case HSI: + case 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 HSI: + RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSI; + break; + case HSE: + RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSE; + break; + case PLL: + RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_PLL; + break; + case HSI48: + RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_SW) | RCC_CFGR_SW_HSI48; + break; + case LSI: + case LSE: + case HSI14: + /* 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 APB Prescale Factor. + * + * @note The APB1 clock frequency must not exceed 36MHz. + * + * @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; +} + + +void rcc_set_prediv(uint32_t prediv) +{ + RCC_CFGR2 = (RCC_CFGR2 & ~RCC_CFGR2_PREDIV) | prediv; +} + + +void rcc_set_mco(uint32_t mcosrc) +{ + RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_MCO) | mcosrc; +} + +/*---------------------------------------------------------------------------*/ +/** @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 HSI; + case RCC_CFGR_SWS_HSE: + return HSE; + case RCC_CFGR_SWS_PLL: + return PLL; + case RCC_CFGR_SWS_HSI48: + return HSI48; + } + + cm3_assert_not_reached(); +} + +void rcc_clock_setup_in_hsi_out_8mhz(void) +{ + rcc_osc_on(HSI); + rcc_wait_for_osc_ready(HSI); + rcc_set_sysclk_source(HSI); + + rcc_set_hpre(RCC_CFGR_HPRE_NODIV); + rcc_set_ppre(RCC_CFGR_PPRE_NODIV); + + flash_set_ws(FLASH_ACR_LATENCY_000_024MHZ); + + rcc_ppre_frequency = 8000000; + rcc_core_frequency = 8000000; +} + +void rcc_clock_setup_in_hsi_out_16mhz(void) +{ + rcc_osc_on(HSI); + rcc_wait_for_osc_ready(HSI); + rcc_set_sysclk_source(HSI); + + rcc_set_hpre(RCC_CFGR_HPRE_NODIV); + rcc_set_ppre(RCC_CFGR_PPRE_NODIV); + + flash_set_ws(FLASH_ACR_LATENCY_000_024MHZ); + + /* 8MHz * 4 / 2 = 16MHz */ + rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_MUL4); + + RCC_CFGR &= ~RCC_CFGR_PLLSRC; + + rcc_osc_on(PLL); + rcc_wait_for_osc_ready(PLL); + rcc_set_sysclk_source(PLL); + + rcc_ppre_frequency = 16000000; + rcc_core_frequency = 16000000; +} + + +void rcc_clock_setup_in_hsi_out_24mhz(void) +{ + rcc_osc_on(HSI); + rcc_wait_for_osc_ready(HSI); + rcc_set_sysclk_source(HSI); + + rcc_set_hpre(RCC_CFGR_HPRE_NODIV); + rcc_set_ppre(RCC_CFGR_PPRE_NODIV); + + flash_set_ws(FLASH_ACR_LATENCY_000_024MHZ); + + /* 8MHz * 6 / 2 = 24MHz */ + rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_MUL6); + + RCC_CFGR &= ~RCC_CFGR_PLLSRC; + + rcc_osc_on(PLL); + rcc_wait_for_osc_ready(PLL); + rcc_set_sysclk_source(PLL); + + rcc_ppre_frequency = 24000000; + rcc_core_frequency = 24000000; +} + +void rcc_clock_setup_in_hsi_out_32mhz(void) +{ + rcc_osc_on(HSI); + rcc_wait_for_osc_ready(HSI); + rcc_set_sysclk_source(HSI); + + rcc_set_hpre(RCC_CFGR_HPRE_NODIV); + rcc_set_ppre(RCC_CFGR_PPRE_NODIV); + + flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ); + + /* 8MHz * 8 / 2 = 32MHz */ + rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_MUL8); + + RCC_CFGR &= ~RCC_CFGR_PLLSRC; + + rcc_osc_on(PLL); + rcc_wait_for_osc_ready(PLL); + rcc_set_sysclk_source(PLL); + + rcc_ppre_frequency = 32000000; + rcc_core_frequency = 32000000; +} + +void rcc_clock_setup_in_hsi_out_40mhz(void) +{ + rcc_osc_on(HSI); + rcc_wait_for_osc_ready(HSI); + rcc_set_sysclk_source(HSI); + + rcc_set_hpre(RCC_CFGR_HPRE_NODIV); + rcc_set_ppre(RCC_CFGR_PPRE_NODIV); + + flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ); + + /* 8MHz * 10 / 2 = 40MHz */ + rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_MUL10); + + RCC_CFGR &= ~RCC_CFGR_PLLSRC; + + rcc_osc_on(PLL); + rcc_wait_for_osc_ready(PLL); + rcc_set_sysclk_source(PLL); + + rcc_ppre_frequency = 40000000; + rcc_core_frequency = 40000000; +} + +void rcc_clock_setup_in_hsi_out_48mhz(void) +{ + rcc_osc_on(HSI); + rcc_wait_for_osc_ready(HSI); + rcc_set_sysclk_source(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_CFGR &= ~RCC_CFGR_PLLSRC; + + rcc_osc_on(PLL); + rcc_wait_for_osc_ready(PLL); + rcc_set_sysclk_source(PLL); + + rcc_ppre_frequency = 48000000; + rcc_core_frequency = 48000000; +} + + +#define _RCC_REG(i) MMIO32(RCC_BASE + ((i) >> 5)) +#define _RCC_BIT(i) (1 << ((i) & 0x1f)) + +void rcc_periph_clock_enable(enum rcc_periph_clken periph) +{ + _RCC_REG(periph) |= _RCC_BIT(periph); +} + +void rcc_periph_clock_disable(enum rcc_periph_clken periph) +{ + _RCC_REG(periph) &= ~_RCC_BIT(periph); +} + +void rcc_periph_reset_pulse(enum rcc_periph_rst periph) +{ + _RCC_REG(periph) |= _RCC_BIT(periph); + _RCC_REG(periph) &= ~_RCC_BIT(periph); +} + +void rcc_periph_reset_hold(enum rcc_periph_rst periph) +{ + _RCC_REG(periph) |= _RCC_BIT(periph); +} + +void rcc_periph_reset_release(enum rcc_periph_rst periph) +{ + _RCC_REG(periph) &= ~_RCC_BIT(periph); +} + +#undef _RCC_REG +#undef _RCC_BIT + +/**@}*/ + |