micropython/ports/stm32/powerctrl.c
Damien George 8031b7a25c stm32/powerctrl: Deselect PLLSAI as 48MHz src before turning off PLLSAI.
On the STM32F722 (at least, but STM32F767 is not affected) the CK48MSEL bit
must be deselected before PLLSAION is turned off, or else the 48MHz
peripherals (RNG, SDMMC, USB) may get stuck without a clock source.

In such "lock up" cases it seems that these peripherals are still being
clocked from the PLLSAI even though the CK48MSEL bit is turned off.  A hard
reset does not get them out of this stuck state.  Enabling the PLLSAI and
then disabling it does get them out.  A test case to see this is:

    import machine, pyb
    for i in range(100):
        machine.freq(122_000000)
        machine.freq(120_000000)
        print(i, [pyb.rng() for _ in range(4)])

On occasion the RNG will just return 0's, but will get fixed again on the
next loop (when PLLSAI is enabled by the change to a SYSCLK of 122MHz).

Fixes issue #4696.
2019-04-29 16:31:32 +10:00

403 lines
14 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;
}
// 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)
// Deselect PLLSAI as 48MHz source if we were using it
RCC->DCKCFGR2 &= ~RCC_DCKCFGR2_CK48MSEL;
// 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;
#if defined(STM32F7)
// Enable the internal (eg RTC) wakeup sources
// See Errata 2.2.2 "Wakeup from Standby mode when the back-up SRAM regulator is enabled"
PWR->CSR1 |= PWR_CSR1_EIWUP;
#endif
// enter standby mode
HAL_PWR_EnterSTANDBYMode();
// we never return; MCU is reset on exit from standby
}