You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

487 lines
10 KiB

/** @defgroup rcc_file RCC peripheral API
*
* @ingroup peripheral_apis
* 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
*/
#include <libopencm3/cm3/assert.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/pwr.h>
#include <libopencm3/stm32/flash.h>
/**@{*/
uint32_t rcc_ahb_frequency = 16000000;
uint32_t rcc_apb1_frequency = 16000000;
uint32_t rcc_apb2_frequency = 16000000;
// All PLL configurations without PLLM. PLLM should be set to the input clock
// frequency in MHz.
const struct rcc_clock_scale rcc_3v3[RCC_CLOCK_3V3_END] = {
{ /* 216MHz */
.plln = 432,
.pllp = 2,
.pllq = 9,
.hpre = RCC_CFGR_HPRE_DIV_NONE,
.ppre1 = RCC_CFGR_PPRE_DIV_4,
.ppre2 = RCC_CFGR_PPRE_DIV_2,
.vos_scale = PWR_SCALE1,
.overdrive = 1,
.flash_waitstates = 7,
.ahb_frequency = 216000000,
.apb1_frequency = 54000000,
.apb2_frequency = 108000000,
},
{ /* 168MHz */
.plln = 336,
.pllp = 2,
.pllq = 7,
.hpre = RCC_CFGR_HPRE_DIV_NONE,
.ppre1 = RCC_CFGR_PPRE_DIV_4,
.ppre2 = RCC_CFGR_PPRE_DIV_2,
.vos_scale = PWR_SCALE2,
.overdrive = 1,
.flash_waitstates = 5,
.ahb_frequency = 168000000,
.apb1_frequency = 42000000,
.apb2_frequency = 84000000,
},
{ /* 120MHz */
.plln = 240,
.pllp = 2,
.pllq = 5,
.hpre = RCC_CFGR_HPRE_DIV_NONE,
.ppre1 = RCC_CFGR_PPRE_DIV_4,
.ppre2 = RCC_CFGR_PPRE_DIV_2,
.vos_scale = PWR_SCALE3,
.overdrive = 0,
.flash_waitstates = 3,
.ahb_frequency = 120000000,
.apb1_frequency = 30000000,
.apb2_frequency = 60000000,
},
{ /* 72MHz */
.plln = 144,
.pllp = 2,
.pllq = 3,
.hpre = RCC_CFGR_HPRE_DIV_NONE,
.ppre1 = RCC_CFGR_PPRE_DIV_4,
.ppre2 = RCC_CFGR_PPRE_DIV_2,
.vos_scale = PWR_SCALE3,
.overdrive = 0,
.flash_waitstates = 2,
.ahb_frequency = 72000000,
.apb1_frequency = 18000000,
.apb2_frequency = 36000000,
},
{ /* 48MHz */
.plln = 192,
.pllp = 4,
.pllq = 4,
.hpre = RCC_CFGR_HPRE_DIV_NONE,
.ppre1 = RCC_CFGR_PPRE_DIV_2,
.ppre2 = RCC_CFGR_PPRE_DIV_2,
.vos_scale = PWR_SCALE3,
.overdrive = 0,
.flash_waitstates = 1,
.ahb_frequency = 48000000,
.apb1_frequency = 24000000,
.apb2_frequency = 24000000,
},
{ /* 24MHz */
.plln = 192,
.pllp = 8,
.pllq = 4,
.hpre = RCC_CFGR_HPRE_DIV_NONE,
.ppre1 = RCC_CFGR_PPRE_DIV_NONE,
.ppre2 = RCC_CFGR_PPRE_DIV_NONE,
.vos_scale = PWR_SCALE3,
.overdrive = 0,
.flash_waitstates = 0,
.ahb_frequency = 24000000,
.apb1_frequency = 24000000,
.apb2_frequency = 24000000,
}
};
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;
}
}
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;
}
}
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;
}
}
int rcc_osc_ready_int_flag(enum rcc_osc osc)
{
switch (osc) {
case RCC_PLL:
return ((RCC_CIR & RCC_CIR_PLLRDYF) != 0);
break;
case RCC_HSE:
return ((RCC_CIR & RCC_CIR_HSERDYF) != 0);
break;
case RCC_HSI:
return ((RCC_CIR & RCC_CIR_HSIRDYF) != 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();
}
void rcc_css_int_clear(void)
{
RCC_CIR |= RCC_CIR_CSSC;
}
int rcc_css_int_flag(void)
{
return ((RCC_CIR & RCC_CIR_CSSF) != 0);
}
void rcc_wait_for_osc_ready(enum rcc_osc osc)
{
switch (osc) {
case RCC_PLL:
while ((RCC_CR & RCC_CR_PLLRDY) == 0);
break;
case RCC_HSE:
while ((RCC_CR & RCC_CR_HSERDY) == 0);
break;
case RCC_HSI:
while ((RCC_CR & RCC_CR_HSIRDY) == 0);
break;
case RCC_LSE:
while ((RCC_BDCR & RCC_BDCR_LSERDY) == 0);
break;
case RCC_LSI:
while ((RCC_CSR & RCC_CSR_LSIRDY) == 0);
break;
}
}
void rcc_wait_for_sysclk_status(enum rcc_osc osc)
{
switch (osc) {
case RCC_PLL:
while ((RCC_CFGR & ((1 << 1) | (1 << 0))) != RCC_CFGR_SWS_PLL);
break;
case RCC_HSE:
while ((RCC_CFGR & ((1 << 1) | (1 << 0))) != RCC_CFGR_SWS_HSE);
break;
case RCC_HSI:
while ((RCC_CFGR & ((1 << 1) | (1 << 0))) != 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;
}
}
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;
}
}
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 &= ~(1 << 22);
RCC_PLLCFGR = (reg32 | (pllsrc << 22));
}
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_rtcpre(uint32_t rtcpre)
{
uint32_t reg32;
reg32 = RCC_CFGR;
reg32 &= ~(RCC_CFGR_RTCPRE_MASK << RCC_CFGR_RTCPRE_SHIFT);
RCC_CFGR = (reg32 | (rtcpre << RCC_CFGR_RTCPRE_SHIFT));
}
void rcc_set_main_pll_hsi(uint32_t pllm, uint32_t plln, uint32_t pllp,
uint32_t pllq)
{
RCC_PLLCFGR = (pllm << RCC_PLLCFGR_PLLM_SHIFT) |
(plln << RCC_PLLCFGR_PLLN_SHIFT) |
(((pllp >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT) |
(pllq << RCC_PLLCFGR_PLLQ_SHIFT);
}
void rcc_set_main_pll_hse(uint32_t pllm, uint32_t plln, uint32_t pllp,
uint32_t pllq)
{
RCC_PLLCFGR = (pllm << RCC_PLLCFGR_PLLM_SHIFT) |
(plln << RCC_PLLCFGR_PLLN_SHIFT) |
(((pllp >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT) |
RCC_PLLCFGR_PLLSRC |
(pllq << RCC_PLLCFGR_PLLQ_SHIFT);
}
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;
}
void rcc_clock_setup_hse(const struct rcc_clock_scale *clock, uint32_t hse_mhz)
{
uint8_t pllm = hse_mhz;
/* Enable internal high-speed oscillator. */
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. */
rcc_osc_on(RCC_HSE);
rcc_wait_for_osc_ready(RCC_HSE);
rcc_periph_clock_enable(RCC_PWR);
pwr_set_vos_scale(clock->vos_scale);
if (clock->overdrive) {
pwr_enable_overdrive();
}
/*
* Set prescalers for AHB, ADC, ABP1, ABP2.
* 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_hse(pllm, clock->plln,
clock->pllp, clock->pllq);
/* Enable PLL oscillator and wait for it to stabilize. */
rcc_osc_on(RCC_PLL);
rcc_wait_for_osc_ready(RCC_PLL);
/* Configure flash settings. */
flash_set_ws(clock->flash_waitstates);
flash_art_enable();
flash_prefetch_enable();
/* 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 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. */
rcc_osc_off(RCC_HSI);
}
void rcc_clock_setup_hsi(const struct rcc_clock_scale *clock)
{
uint8_t pllm = 16;
/* Enable internal high-speed oscillator. */
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);
rcc_periph_clock_enable(RCC_PWR);
pwr_set_vos_scale(clock->vos_scale);
if (clock->overdrive) {
pwr_enable_overdrive();
}
/*
* Set prescalers for AHB, ADC, ABP1, ABP2.
* Do this before touching the PLL (TODO: why?).
*/
rcc_set_hpre(clock->hpre);
rcc_set_ppre1(clock->ppre1);
rcc_set_ppre2(clock->ppre2);
rcc_set_main_pll_hsi(pllm, clock->plln,
clock->pllp, clock->pllq);
/* Enable PLL oscillator and wait for it to stabilize. */
rcc_osc_on(RCC_PLL);
rcc_wait_for_osc_ready(RCC_PLL);
/* Configure flash settings. */
flash_set_ws(clock->flash_waitstates);
flash_art_enable();
flash_prefetch_enable();
/* 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 clock frequencies used. */
rcc_ahb_frequency = clock->ahb_frequency;
rcc_apb1_frequency = clock->apb1_frequency;
rcc_apb2_frequency = clock->apb2_frequency;
}
/**@}*/