From 8e6b17df3e9e85f5199ca36f394e2a59a135079e Mon Sep 17 00:00:00 2001
From: Emilio Corigliano <emilio.corigliano@skywarder.eu>
Date: Thu, 8 Dec 2022 14:01:37 +0000
Subject: [PATCH] [ClockUtils] Fixed errors in retrieving clock frequency of
APB buses
- Created two methods getAPBTimersClock() and getAPBPeripheralsClock()
- Fixed wrong computation of APB2 frequency
- Previous usages of getAPBFrequency() now use getAPBTimersClock() for usage compatibility
---
.../drivers/canbus/CanDriver/CanDriver.cpp | 9 ++-
src/shared/drivers/timer/TimerUtils.h | 2 +-
src/shared/drivers/usart/USART.cpp | 11 ++-
src/shared/utils/ClockUtils.h | 74 ++++++++++++++++---
4 files changed, 78 insertions(+), 18 deletions(-)
diff --git a/src/shared/drivers/canbus/CanDriver/CanDriver.cpp b/src/shared/drivers/canbus/CanDriver/CanDriver.cpp
index dc9469bdd..38c5da81a 100644
--- a/src/shared/drivers/canbus/CanDriver/CanDriver.cpp
+++ b/src/shared/drivers/canbus/CanDriver/CanDriver.cpp
@@ -117,8 +117,13 @@ CanbusDriver::BitTiming CanbusDriver::calcBitTiming(AutoBitTiming autoBt)
uint8_t NOpt = 5;
BitTiming cfgIter;
- cfgIter.SJW = 0;
- uint32_t apbclk = ClockUtils::getAPBFrequency(ClockUtils::APB::APB1);
+ cfgIter.SJW = 0;
+ /*
+ * TODO: This is modified only for compatibility with the past, MUST check
+ * the clock settings in order to use the right method
+ * 'getAPBPeripheralsClock()'
+ */
+ uint32_t apbclk = ClockUtils::getAPBTimersClock(ClockUtils::APB::APB1);
// Iterate over the possible number of quanta in a bit to find the best
// settings
diff --git a/src/shared/drivers/timer/TimerUtils.h b/src/shared/drivers/timer/TimerUtils.h
index 7d619419f..09ecfdc14 100644
--- a/src/shared/drivers/timer/TimerUtils.h
+++ b/src/shared/drivers/timer/TimerUtils.h
@@ -379,7 +379,7 @@ inline ClockUtils::APB TimerUtils::getTimerInputClock(const TIM_TypeDef *timer)
inline uint32_t TimerUtils::getPrescalerInputFrequency(const TIM_TypeDef *timer)
{
- return ClockUtils::getAPBFrequency(getTimerInputClock(timer));
+ return ClockUtils::getAPBTimersClock(getTimerInputClock(timer));
}
inline uint32_t TimerUtils::getFrequency(TIM_TypeDef *timer)
diff --git a/src/shared/drivers/usart/USART.cpp b/src/shared/drivers/usart/USART.cpp
index 765b4dfcc..05d9e5f24 100644
--- a/src/shared/drivers/usart/USART.cpp
+++ b/src/shared/drivers/usart/USART.cpp
@@ -445,11 +445,16 @@ void USART::setBaudrate(Baudrate baudrate)
*/
miosix::InterruptDisableLock dLock;
- // USART1 and USART6 is always connected to the APB2, while all the others
+ /*
+ * TODO: This is modified only for compatibility with the past, MUST check
+ * the clock settings in order to use the right method
+ * 'getAPBPeripheralsClock()'
+ */
+ // USART1 and USART6 are always connected to the APB2, while all the others
// UART/USART peripherals are always connected to APB1
- uint32_t f = ClockUtils::getAPBFrequency(
+ uint32_t f = ClockUtils::getAPBTimersClock(
(id == 1 || id == 6 ? ClockUtils::APB::APB2 // High speed APB2
- : ClockUtils::APB::APB1)); // Low speed APB1,
+ : ClockUtils::APB::APB1)); // Low speed APB1
// <<4 in order to shift to left of 4 positions, to create a fixed point
// number of 4 decimal digits /8 == >>3 in order to divide per 8 (from the
diff --git a/src/shared/utils/ClockUtils.h b/src/shared/utils/ClockUtils.h
index addbdafb8..e7fca74c5 100644
--- a/src/shared/utils/ClockUtils.h
+++ b/src/shared/utils/ClockUtils.h
@@ -41,12 +41,20 @@ enum class APB
};
/**
- * @brief Computes the output frequency for the given APB bus.
+ * @brief Computes the output clock frequency for peripherals on the given APB.
*
* @param bus Advanced Peripheral Bus
- * @return Prescaler input frequency.
+ * @return Clock frequency of peripherals.
*/
-uint32_t getAPBFrequency(APB bus);
+uint32_t getAPBPeripheralsClock(APB bus);
+
+/**
+ * @brief Computes the output clock frequency for timers on the given APB.
+ *
+ * @param bus Advanced Peripheral Bus
+ * @return Clock frequency of timers.
+ */
+uint32_t getAPBTimersClock(APB bus);
/**
* @brief Enables a peripheral clock source from the APB1 and APB2 peripheral
@@ -62,18 +70,60 @@ bool disablePeripheralClock(void* peripheral);
} // namespace ClockUtils
-inline uint32_t ClockUtils::getAPBFrequency(APB bus)
+inline uint32_t ClockUtils::getAPBPeripheralsClock(APB bus)
+{
+ // The global variable SystemCoreClock from ARM's CMIS allows to know the
+ // CPU frequency.
+ uint32_t inputFrequency = SystemCoreClock;
+
+ // The APB frequency may be a submultiple of the CPU frequency, due to the
+ // bus at which the peripheral is connected being slower.
+ // The RCC->CFGR register tells us how slower the APB bus is running.
+ if (bus == APB::APB1)
+ {
+ // The position of the PPRE1 bit in RCC->CFGR is different in some stm32
+#ifdef _ARCH_CORTEXM3_STM32
+ const uint32_t ppre1 = 8;
+#elif _ARCH_CORTEXM4_STM32F4 | _ARCH_CORTEXM3_STM32F2
+ const uint32_t ppre1 = 10;
+#else
+#error "Architecture not supported by TimerUtils"
+#endif
+
+ if (RCC->CFGR & RCC_CFGR_PPRE1_2)
+ {
+ inputFrequency /= 2 << ((RCC->CFGR >> ppre1) & 0b11);
+ }
+ }
+ else
+ {
+ // The position of the PPRE2 bit in RCC->CFGR is different in some stm32
+#ifdef _ARCH_CORTEXM3_STM32
+ const uint32_t ppre2 = 11;
+#elif _ARCH_CORTEXM4_STM32F4 | _ARCH_CORTEXM3_STM32F2
+ const uint32_t ppre2 = 13;
+#else
+#error "Architecture not supported by TimerUtils"
+#endif
+
+ if (RCC->CFGR & RCC_CFGR_PPRE2_2)
+ {
+ inputFrequency /= 2 << ((RCC->CFGR >> ppre2) & 0b11);
+ }
+ }
+
+ return inputFrequency;
+}
+
+inline uint32_t ClockUtils::getAPBTimersClock(APB bus)
{
// The global variable SystemCoreClock from ARM's CMIS allows to know the
// CPU frequency.
uint32_t inputFrequency = SystemCoreClock;
- // The timer frequency may be a submultiple of the CPU frequency, due to the
+ // The APB frequency may be a submultiple of the CPU frequency, due to the
// bus at which the peripheral is connected being slower.
- // The RCC-ZCFGR register tells us how slower the APB bus is running.
- // The following formula takes into account that if the APB1 clock is
- // divided by a factor of two or grater, the timer is clocked at twice the
- // bus interface.
+ // The RCC->CFGR register tells us how slower the APB bus is running.
if (bus == APB::APB1)
{
// The position of the PPRE1 bit in RCC->CFGR is different in some stm32
@@ -87,7 +137,7 @@ inline uint32_t ClockUtils::getAPBFrequency(APB bus)
if (RCC->CFGR & RCC_CFGR_PPRE1_2)
{
- inputFrequency /= 1 << ((RCC->CFGR >> ppre1) & 0x3);
+ inputFrequency /= 1 << ((RCC->CFGR >> ppre1) & 0b11);
}
}
else
@@ -103,7 +153,7 @@ inline uint32_t ClockUtils::getAPBFrequency(APB bus)
if (RCC->CFGR & RCC_CFGR_PPRE2_2)
{
- inputFrequency /= 1 << ((RCC->CFGR >> ppre2) >> 0x3);
+ inputFrequency /= 1 << ((RCC->CFGR >> ppre2) & 0b11);
}
}
@@ -448,7 +498,7 @@ inline bool ClockUtils::disablePeripheralClock(void* peripheral)
RCC->APB1ENR &= ~RCC_APB1ENR_TIM2EN;
break;
case TIM3_BASE:
- RCC->APB1ENR &= ~RCC_APB1ENR_TIM2EN;
+ RCC->APB1ENR &= ~RCC_APB1ENR_TIM3EN;
break;
case TIM4_BASE:
RCC->APB1ENR &= ~RCC_APB1ENR_TIM4EN;
--
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