From 7581c0038dbf19da87a159e48bf7b114d3f42bf6 Mon Sep 17 00:00:00 2001
From: Nico Tonnhofer <wurstnase.reprap@gmail.com>
Date: Tue, 25 Jul 2017 20:15:12 +0200
Subject: [PATCH] stm32: correct some clock settings

---
 arduino_stm32f411.h      | 13 +++++++++----
 cmsis-system_stm32f4xx.c |  4 +++-
 cmsis-system_stm32f4xx.h |  4 ----
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/arduino_stm32f411.h b/arduino_stm32f411.h
index c4fd190..6b1bae0 100644
--- a/arduino_stm32f411.h
+++ b/arduino_stm32f411.h
@@ -24,8 +24,8 @@
 */
 #define RX_UART1            PA_10
 #define TX_UART1            PA_9
-#define RX_UART2             PA_3
-#define TX_UART2             PA_2
+#define RX_UART2            PA_3
+#define TX_UART2            PA_2
 #define RX_UART6            PA_12
 #define TX_UART6            PA_11
 
@@ -33,8 +33,13 @@
 */
 #define F_CPU __SYSTEM_CLOCK
 
-#define PPRE1_DIV (RCC_CFGR_PPRE1_DIV2) // 0x1000
-#define PPRE2_DIV (RCC_CFGR_PPRE2_DIV1) // 0x0000
+#if defined STM32F411xE
+  #define PPRE1_DIV (RCC_CFGR_PPRE1_DIV2)
+  #define PPRE2_DIV (RCC_CFGR_PPRE2_DIV1)
+#elif defined STM32F446xx
+  #define PPRE1_DIV (RCC_CFGR_PPRE1_DIV4)
+  #define PPRE2_DIV (RCC_CFGR_PPRE2_DIV2)
+#endif
 
 #if PPRE1_DIV > 0
   #define APB1_DIV (1 << ((PPRE1_DIV >> 10) - 3))
diff --git a/cmsis-system_stm32f4xx.c b/cmsis-system_stm32f4xx.c
index ad14fc1..f3a02ae 100644
--- a/cmsis-system_stm32f4xx.c
+++ b/cmsis-system_stm32f4xx.c
@@ -325,7 +325,7 @@ void SetSysClock(void)
     #define LATENCY FLASH_ACR_LATENCY_2WS
   #elif __SYSTEM_CLOCK == 180000000
     #if !defined(STM32F446xx)
-      #warning You are running the controller out of specification! 180 MHz!
+      #error You are running the controller out of specification! 180 MHz!
     #endif
     #define PLLM 4
     #define PLLN 180
@@ -371,6 +371,8 @@ void SetSysClock(void)
 
   RCC->CFGR &= ~(RCC_CFGR_PPRE1 | RCC_CFGR_PPRE2);
   RCC->CFGR |= PPRE1_DIV | PPRE2_DIV;
+
+  RCC->DCKCFGR |= RCC_DCKCFGR_TIMPRE;
 }
 
 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
diff --git a/cmsis-system_stm32f4xx.h b/cmsis-system_stm32f4xx.h
index 7ce78f8..3ca356a 100644
--- a/cmsis-system_stm32f4xx.h
+++ b/cmsis-system_stm32f4xx.h
@@ -55,10 +55,6 @@
  extern "C" {
 #endif
 
-// #define __SYSTEM_CLOCK 96000000
-// #define __SYSTEM_CLOCK 100000000
-// #define __SYSTEM_CLOCK 108000000 // Overclocking is not recommended!
-
 /* 
   This variable is updated in by calling CMSIS function SystemCoreClockUpdate()
 */