circuitpython/ports/stm32/powerctrl.c
Francisco J. Manno f938e70c69 stm32: Add compile-time option to use HSI as clock source.
To use HSI instead of HSE define MICROPY_HW_CLK_USE_HSI as 1 in the board
configuration file.  The default is to use HSE.

HSI has been made the default for the NUCLEO_F401RE board to serve as an
example, and because early revisions of this board need a hardware
modification to get HSE working.
2019-03-05 15:49:08 +11:00

397 lines
13 KiB
C

/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2013-2018 Damien P. George
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "py/mperrno.h"
#include "py/mphal.h"
#include "powerctrl.h"
#include "rtc.h"
#include "genhdr/pllfreqtable.h"
#if !defined(STM32F0)
// Assumes that PLL is used as the SYSCLK source
int powerctrl_rcc_clock_config_pll(RCC_ClkInitTypeDef *rcc_init, uint32_t sysclk_mhz, bool need_pllsai) {
uint32_t flash_latency;
#if defined(STM32F7)
if (need_pllsai) {
// Configure PLLSAI at 48MHz for those peripherals that need this freq
const uint32_t pllsain = 192;
const uint32_t pllsaip = 4;
const uint32_t pllsaiq = 2;
RCC->PLLSAICFGR = pllsaiq << RCC_PLLSAICFGR_PLLSAIQ_Pos
| (pllsaip / 2 - 1) << RCC_PLLSAICFGR_PLLSAIP_Pos
| pllsain << RCC_PLLSAICFGR_PLLSAIN_Pos;
RCC->CR |= RCC_CR_PLLSAION;
uint32_t ticks = mp_hal_ticks_ms();
while (!(RCC->CR & RCC_CR_PLLSAIRDY)) {
if (mp_hal_ticks_ms() - ticks > 200) {
return -MP_ETIMEDOUT;
}
}
RCC->DCKCFGR2 |= RCC_DCKCFGR2_CK48MSEL;
} else {
RCC->DCKCFGR2 &= ~RCC_DCKCFGR2_CK48MSEL;
}
// If possible, scale down the internal voltage regulator to save power
uint32_t volt_scale;
if (sysclk_mhz <= 151) {
volt_scale = PWR_REGULATOR_VOLTAGE_SCALE3;
} else if (sysclk_mhz <= 180) {
volt_scale = PWR_REGULATOR_VOLTAGE_SCALE2;
} else {
volt_scale = PWR_REGULATOR_VOLTAGE_SCALE1;
}
if (HAL_PWREx_ControlVoltageScaling(volt_scale) != HAL_OK) {
return -MP_EIO;
}
// These flash_latency values assume a supply voltage between 2.7V and 3.6V
if (sysclk_mhz <= 30) {
flash_latency = FLASH_LATENCY_0;
} else if (sysclk_mhz <= 60) {
flash_latency = FLASH_LATENCY_1;
} else if (sysclk_mhz <= 90) {
flash_latency = FLASH_LATENCY_2;
} else if (sysclk_mhz <= 120) {
flash_latency = FLASH_LATENCY_3;
} else if (sysclk_mhz <= 150) {
flash_latency = FLASH_LATENCY_4;
} else if (sysclk_mhz <= 180) {
flash_latency = FLASH_LATENCY_5;
} else if (sysclk_mhz <= 210) {
flash_latency = FLASH_LATENCY_6;
} else {
flash_latency = FLASH_LATENCY_7;
}
#elif defined(MICROPY_HW_FLASH_LATENCY)
flash_latency = MICROPY_HW_FLASH_LATENCY;
#else
flash_latency = FLASH_LATENCY_5;
#endif
rcc_init->SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
if (HAL_RCC_ClockConfig(rcc_init, flash_latency) != HAL_OK) {
return -MP_EIO;
}
return 0;
}
#endif
#if !(defined(STM32F0) || defined(STM32L4))
STATIC uint32_t calc_ahb_div(uint32_t wanted_div) {
if (wanted_div <= 1) { return RCC_SYSCLK_DIV1; }
else if (wanted_div <= 2) { return RCC_SYSCLK_DIV2; }
else if (wanted_div <= 4) { return RCC_SYSCLK_DIV4; }
else if (wanted_div <= 8) { return RCC_SYSCLK_DIV8; }
else if (wanted_div <= 16) { return RCC_SYSCLK_DIV16; }
else if (wanted_div <= 64) { return RCC_SYSCLK_DIV64; }
else if (wanted_div <= 128) { return RCC_SYSCLK_DIV128; }
else if (wanted_div <= 256) { return RCC_SYSCLK_DIV256; }
else { return RCC_SYSCLK_DIV512; }
}
STATIC uint32_t calc_apb_div(uint32_t wanted_div) {
if (wanted_div <= 1) { return RCC_HCLK_DIV1; }
else if (wanted_div <= 2) { return RCC_HCLK_DIV2; }
else if (wanted_div <= 4) { return RCC_HCLK_DIV4; }
else if (wanted_div <= 8) { return RCC_HCLK_DIV8; }
else { return RCC_SYSCLK_DIV16; }
}
int powerctrl_set_sysclk(uint32_t sysclk, uint32_t ahb, uint32_t apb1, uint32_t apb2) {
// Return straightaway if the clocks are already at the desired frequency
if (sysclk == HAL_RCC_GetSysClockFreq()
&& ahb == HAL_RCC_GetHCLKFreq()
&& apb1 == HAL_RCC_GetPCLK1Freq()
&& apb2 == HAL_RCC_GetPCLK2Freq()) {
return 0;
}
// Default PLL parameters that give 48MHz on PLL48CK
uint32_t m = HSE_VALUE / 1000000, n = 336, p = 2, q = 7;
uint32_t sysclk_source;
bool need_pllsai = false;
// Search for a valid PLL configuration that keeps USB at 48MHz
uint32_t sysclk_mhz = sysclk / 1000000;
for (const uint16_t *pll = &pll_freq_table[MP_ARRAY_SIZE(pll_freq_table) - 1]; pll >= &pll_freq_table[0]; --pll) {
uint32_t sys = *pll & 0xff;
if (sys <= sysclk_mhz) {
m = (*pll >> 10) & 0x3f;
p = ((*pll >> 7) & 0x6) + 2;
if (m == 0) {
// special entry for using HSI directly
sysclk_source = RCC_SYSCLKSOURCE_HSI;
} else if (m == 1) {
// special entry for using HSE directly
sysclk_source = RCC_SYSCLKSOURCE_HSE;
} else {
// use PLL
sysclk_source = RCC_SYSCLKSOURCE_PLLCLK;
uint32_t vco_out = sys * p;
n = vco_out * m / (HSE_VALUE / 1000000);
q = vco_out / 48;
#if defined(STM32F7)
need_pllsai = vco_out % 48 != 0;
#endif
}
goto set_clk;
}
}
return -MP_EINVAL;
set_clk:
// Let the USB CDC have a chance to process before we change the clock
mp_hal_delay_ms(5);
// Desired system clock source is in sysclk_source
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
if (sysclk_source == RCC_SYSCLKSOURCE_PLLCLK) {
// Set HSE as system clock source to allow modification of the PLL configuration
// We then change to PLL after re-configuring PLL
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSE;
} else {
// Directly set the system clock source as desired
RCC_ClkInitStruct.SYSCLKSource = sysclk_source;
}
// Determine the bus clock dividers
// Note: AHB freq required to be >= 14.2MHz for USB operation
RCC_ClkInitStruct.AHBCLKDivider = calc_ahb_div(sysclk / ahb);
#if !defined(STM32H7)
ahb = sysclk >> AHBPrescTable[RCC_ClkInitStruct.AHBCLKDivider >> RCC_CFGR_HPRE_Pos];
#endif
RCC_ClkInitStruct.APB1CLKDivider = calc_apb_div(ahb / apb1);
RCC_ClkInitStruct.APB2CLKDivider = calc_apb_div(ahb / apb2);
#if MICROPY_HW_CLK_LAST_FREQ
// Save the bus dividers for use later
uint32_t h = RCC_ClkInitStruct.AHBCLKDivider >> 4;
uint32_t b1 = RCC_ClkInitStruct.APB1CLKDivider >> 10;
uint32_t b2 = RCC_ClkInitStruct.APB2CLKDivider >> 10;
#endif
// Configure clock
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
return -MP_EIO;
}
#if defined(STM32F7)
// Turn PLLSAI off because we are changing PLLM (which drives PLLSAI)
RCC->CR &= ~RCC_CR_PLLSAION;
#endif
// Re-configure PLL
// Even if we don't use the PLL for the system clock, we still need it for USB, RNG and SDIO
RCC_OscInitTypeDef RCC_OscInitStruct;
RCC_OscInitStruct.OscillatorType = MICROPY_HW_RCC_OSCILLATOR_TYPE;
RCC_OscInitStruct.HSEState = MICROPY_HW_RCC_HSE_STATE;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = MICROPY_HW_RCC_PLL_SRC;
RCC_OscInitStruct.PLL.PLLM = m;
RCC_OscInitStruct.PLL.PLLN = n;
RCC_OscInitStruct.PLL.PLLP = p;
RCC_OscInitStruct.PLL.PLLQ = q;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
return -MP_EIO;
}
// Set PLL as system clock source if wanted
if (sysclk_source == RCC_SYSCLKSOURCE_PLLCLK) {
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
int ret = powerctrl_rcc_clock_config_pll(&RCC_ClkInitStruct, sysclk_mhz, need_pllsai);
if (ret != 0) {
return ret;
}
}
#if MICROPY_HW_CLK_LAST_FREQ
// Save settings in RTC backup register to reconfigure clocks on hard-reset
#if defined(STM32F7)
#define FREQ_BKP BKP31R
#else
#define FREQ_BKP BKP19R
#endif
// qqqqqqqq pppppppp nnnnnnnn nnmmmmmm
// qqqqQQQQ ppppppPP nNNNNNNN NNMMMMMM
// 222111HH HHQQQQPP nNNNNNNN NNMMMMMM
p = (p / 2) - 1;
RTC->FREQ_BKP = m
| (n << 6) | (p << 16) | (q << 18)
| (h << 22)
| (b1 << 26)
| (b2 << 29);
#endif
return 0;
}
#endif
void powerctrl_enter_stop_mode(void) {
// Disable IRQs so that the IRQ that wakes the device from stop mode is not
// executed until after the clocks are reconfigured
uint32_t irq_state = disable_irq();
#if defined(STM32L4)
// Configure the MSI as the clock source after waking up
__HAL_RCC_WAKEUPSTOP_CLK_CONFIG(RCC_STOP_WAKEUPCLOCK_MSI);
#endif
#if !defined(STM32F0) && !defined(STM32L4)
// takes longer to wake but reduces stop current
HAL_PWREx_EnableFlashPowerDown();
#endif
# if defined(STM32F7)
HAL_PWR_EnterSTOPMode((PWR_CR1_LPDS | PWR_CR1_LPUDS | PWR_CR1_FPDS | PWR_CR1_UDEN), PWR_STOPENTRY_WFI);
# else
HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);
#endif
// reconfigure the system clock after waking up
#if defined(STM32F0)
// Enable HSI48
__HAL_RCC_HSI48_ENABLE();
while (!__HAL_RCC_GET_FLAG(RCC_FLAG_HSI48RDY)) {
}
// Select HSI48 as system clock source
MODIFY_REG(RCC->CFGR, RCC_CFGR_SW, RCC_SYSCLKSOURCE_HSI48);
while (__HAL_RCC_GET_SYSCLK_SOURCE() != RCC_CFGR_SWS_HSI48) {
}
#else
#if !defined(STM32L4)
// enable clock
__HAL_RCC_HSE_CONFIG(MICROPY_HW_RCC_HSE_STATE);
#if MICROPY_HW_CLK_USE_HSI
__HAL_RCC_HSI_ENABLE();
#endif
while (!__HAL_RCC_GET_FLAG(MICROPY_HW_RCC_FLAG_HSxRDY)) {
}
#endif
// enable PLL
__HAL_RCC_PLL_ENABLE();
while (!__HAL_RCC_GET_FLAG(RCC_FLAG_PLLRDY)) {
}
// select PLL as system clock source
MODIFY_REG(RCC->CFGR, RCC_CFGR_SW, RCC_SYSCLKSOURCE_PLLCLK);
#if defined(STM32H7)
while (__HAL_RCC_GET_SYSCLK_SOURCE() != RCC_CFGR_SWS_PLL1) {
}
#else
while (__HAL_RCC_GET_SYSCLK_SOURCE() != RCC_CFGR_SWS_PLL) {
}
#endif
#if defined(STM32F7)
if (RCC->DCKCFGR2 & RCC_DCKCFGR2_CK48MSEL) {
// Enable PLLSAI if it is selected as 48MHz source
RCC->CR |= RCC_CR_PLLSAION;
while (!(RCC->CR & RCC_CR_PLLSAIRDY)) {
}
}
#endif
#if defined(STM32L4)
// Enable PLLSAI1 for peripherals that use it
RCC->CR |= RCC_CR_PLLSAI1ON;
while (!(RCC->CR & RCC_CR_PLLSAI1RDY)) {
}
#endif
#endif
// Enable IRQs now that all clocks are reconfigured
enable_irq(irq_state);
}
void powerctrl_enter_standby_mode(void) {
rtc_init_finalise();
// We need to clear the PWR wake-up-flag before entering standby, since
// the flag may have been set by a previous wake-up event. Furthermore,
// we need to disable the wake-up sources while clearing this flag, so
// that if a source is active it does actually wake the device.
// See section 5.3.7 of RM0090.
// Note: we only support RTC ALRA, ALRB, WUT and TS.
// TODO support TAMP and WKUP (PA0 external pin).
#if defined(STM32F0)
#define CR_BITS (RTC_CR_ALRAIE | RTC_CR_WUTIE | RTC_CR_TSIE)
#define ISR_BITS (RTC_ISR_ALRAF | RTC_ISR_WUTF | RTC_ISR_TSF)
#else
#define CR_BITS (RTC_CR_ALRAIE | RTC_CR_ALRBIE | RTC_CR_WUTIE | RTC_CR_TSIE)
#define ISR_BITS (RTC_ISR_ALRAF | RTC_ISR_ALRBF | RTC_ISR_WUTF | RTC_ISR_TSF)
#endif
// save RTC interrupts
uint32_t save_irq_bits = RTC->CR & CR_BITS;
// disable RTC interrupts
RTC->CR &= ~CR_BITS;
// clear RTC wake-up flags
RTC->ISR &= ~ISR_BITS;
#if defined(STM32F7)
// disable wake-up flags
PWR->CSR2 &= ~(PWR_CSR2_EWUP6 | PWR_CSR2_EWUP5 | PWR_CSR2_EWUP4 | PWR_CSR2_EWUP3 | PWR_CSR2_EWUP2 | PWR_CSR2_EWUP1);
// clear global wake-up flag
PWR->CR2 |= PWR_CR2_CWUPF6 | PWR_CR2_CWUPF5 | PWR_CR2_CWUPF4 | PWR_CR2_CWUPF3 | PWR_CR2_CWUPF2 | PWR_CR2_CWUPF1;
#elif defined(STM32H7)
// TODO
#elif defined(STM32L4)
// clear all wake-up flags
PWR->SCR |= PWR_SCR_CWUF5 | PWR_SCR_CWUF4 | PWR_SCR_CWUF3 | PWR_SCR_CWUF2 | PWR_SCR_CWUF1;
// TODO
#else
// clear global wake-up flag
PWR->CR |= PWR_CR_CWUF;
#endif
// enable previously-enabled RTC interrupts
RTC->CR |= save_irq_bits;
// enter standby mode
HAL_PWR_EnterSTANDBYMode();
// we never return; MCU is reset on exit from standby
}