From 4a39c8cd53eb1509e5b39d45f18220d3ae0d3410 Mon Sep 17 00:00:00 2001
From: Jason Smith <jason.inet@gmail.com>
Date: Sun, 1 Nov 2020 01:39:30 -0700
Subject: [PATCH] Get STM32 clock rates from framework (#19978)

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>
---
 Marlin/src/HAL/STM32/timers.cpp               | 14 +++++++++-----
 Marlin/src/HAL/STM32/timers.h                 |  3 ++-
 Marlin/src/pins/stm32f4/pins_RUMBA32_common.h |  1 -
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/Marlin/src/HAL/STM32/timers.cpp b/Marlin/src/HAL/STM32/timers.cpp
index b708c4bdab..442aa74d1c 100644
--- a/Marlin/src/HAL/STM32/timers.cpp
+++ b/Marlin/src/HAL/STM32/timers.cpp
@@ -68,26 +68,23 @@
 #endif
 
 #ifdef STM32F0xx
-  #define MCU_TIMER_RATE (F_CPU)      // Frequency of timer peripherals
   #define MCU_STEP_TIMER 16
   #define MCU_TEMP_TIMER 17
 #elif defined(STM32F1xx)
-  #define MCU_TIMER_RATE (F_CPU)
   #define MCU_STEP_TIMER  4
   #define MCU_TEMP_TIMER  2
 #elif defined(STM32F401xC) || defined(STM32F401xE)
-  #define MCU_TIMER_RATE (F_CPU / 2)
   #define MCU_STEP_TIMER  9
   #define MCU_TEMP_TIMER 10
 #elif defined(STM32F4xx) || defined(STM32F7xx)
-  #define MCU_TIMER_RATE (F_CPU / 2)
   #define MCU_STEP_TIMER  6           // STM32F401 has no TIM6, TIM7, or TIM8
   #define MCU_TEMP_TIMER 14           // TIM7 is consumed by Software Serial if used.
 #endif
 
 #ifndef HAL_TIMER_RATE
-  #define HAL_TIMER_RATE MCU_TIMER_RATE
+  #define HAL_TIMER_RATE GetStepperTimerClkFreq()
 #endif
+
 #ifndef STEP_TIMER
   #define STEP_TIMER MCU_STEP_TIMER
 #endif
@@ -115,6 +112,13 @@ HardwareTimer *timer_instance[NUM_HARDWARE_TIMERS] = { nullptr };
 // Public functions
 // ------------------------
 
+uint32_t GetStepperTimerClkFreq() {
+  // Timer input clocks vary between devices, and in some cases between timers on the same device.
+  // Retrieve at runtime to ensure device compatibility. Cache result to avoid repeated overhead.
+  static uint32_t clkfreq = timer_instance[STEP_TIMER_NUM]->getTimerClkFreq();
+  return clkfreq;
+}
+
 // frequency is in Hertz
 void HAL_timer_start(const uint8_t timer_num, const uint32_t frequency) {
   if (!HAL_timer_initialized(timer_num)) {
diff --git a/Marlin/src/HAL/STM32/timers.h b/Marlin/src/HAL/STM32/timers.h
index 5515219ead..de762794ee 100644
--- a/Marlin/src/HAL/STM32/timers.h
+++ b/Marlin/src/HAL/STM32/timers.h
@@ -57,7 +57,8 @@
 
 // TODO: get rid of manual rate/prescale/ticks/cycles taken for procedures in stepper.cpp
 #define STEPPER_TIMER_RATE 2000000 // 2 Mhz
-#define STEPPER_TIMER_PRESCALE ((HAL_TIMER_RATE)/(STEPPER_TIMER_RATE))
+extern uint32_t GetStepperTimerClkFreq();
+#define STEPPER_TIMER_PRESCALE (GetStepperTimerClkFreq() / (STEPPER_TIMER_RATE))
 #define STEPPER_TIMER_TICKS_PER_US ((STEPPER_TIMER_RATE) / 1000000) // stepper timer ticks per µs
 
 #define PULSE_TIMER_RATE STEPPER_TIMER_RATE
diff --git a/Marlin/src/pins/stm32f4/pins_RUMBA32_common.h b/Marlin/src/pins/stm32f4/pins_RUMBA32_common.h
index 9a6a16516c..eee0094ea8 100644
--- a/Marlin/src/pins/stm32f4/pins_RUMBA32_common.h
+++ b/Marlin/src/pins/stm32f4/pins_RUMBA32_common.h
@@ -47,7 +47,6 @@
 
 #define STEP_TIMER 10
 #define TEMP_TIMER 14
-#define HAL_TIMER_RATE                     F_CPU
 
 //
 // Limit Switches