From f5fcbad323f3cb21647662d41f2eaf0e0f1c24fe Mon Sep 17 00:00:00 2001
From: Sasan Golchin <ahmad.golchin@mail.polimi.it>
Date: Tue, 15 Dec 2015 08:48:36 +0100
Subject: [PATCH] Context Switch Timer Interface
A generic interface miosix::ContextSwitchTimer has been added to the
kernel that can play the role of either periodic/aperiodic system timer.
Like other kernel interfaces, there should be provided a proper
implementation for cstimer.
Currently the only available implementation is done for cortexM4_stm32f
which is based on TIM2 timer. Although the implementation is an
aperiodic timer, it is set to act like a periodic timer with T=1ms.
Signed-off-by: Sasan Golchin <ahmad.golchin@mail.polimi.it>
Signed-off-by: Terraneo Federico <fede.tft@miosix.org>
---
Makefile | 2 +-
main.cpp | 47 ++++--------
.../common/interfaces-impl/cstimer.cpp | 71 +++++++++++--------
.../common/interfaces-impl/portability.cpp | 8 +++
miosix/config/Makefile.inc | 1 +
cstimer.h => miosix/interfaces/cstimer.h | 2 +-
6 files changed, 69 insertions(+), 62 deletions(-)
rename cstimer.cpp => miosix/arch/cortexM4_stm32f4/common/interfaces-impl/cstimer.cpp (63%)
rename cstimer.h => miosix/interfaces/cstimer.h (89%)
diff --git a/Makefile b/Makefile
index 69ace418..1f279089 100644
--- a/Makefile
+++ b/Makefile
@@ -19,7 +19,7 @@ SUBDIRS := $(KPATH)
## List here your source files (both .s, .c and .cpp)
##
SRC := \
-main.cpp cstimer.cpp
+main.cpp
##
## List here additional static libraries with relative path
diff --git a/main.cpp b/main.cpp
index 5e20d2f8..69d1f944 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,42 +1,25 @@
-#include <cstdio>
-#include <cmath>
+#include <stdio.h>
+#include <pthread.h>
#include "miosix.h"
#include "kernel/logging.h"
-#include "e20/e20.h"
-#include "cstimer.h"
+#include "interfaces/cstimer.h"
using namespace std;
using namespace miosix;
-void basicTests(){
- ContextSwitchTimer t = ContextSwitchTimer::instance();
- long long chkpoint = 0xFFFFFFFFll+1899760;
- //chkpoint = 0xFFFFFFFFll-20; //Test Case: CHKPNT right really before rollover -> OK
- //chkpoint = 0xFFFFFFFFll-2000; //Test Case: CHKPNT right before rollover -> OK
- //chkpoint = 0xFFFFFFFFll+2000; //Test Case: CHKPNT right afrer rollover -> OK
- //chkpoint = 0xFFFFFFFFll+20; //Test Case: CHKPNT right really afrer rollover -> OK
- t.setNextInterrupt(chkpoint); //checkpoint near the rollover
- while(1){
- Thread::sleep(10000);
- printf("-CNT: %llu , NEXT CHKPNT: %llu\n",t.getCurrentTick(),t.getNextInterrupt());
-
- }
-}
-void rightAfterCurrentTime(){
- ContextSwitchTimer t = ContextSwitchTimer::instance();
-
- while(1){
- Thread::sleep(10000);
- //checkpoint near the current tick
- //A chkpoint with dist. less than 80 is not set in time => lost!
- t.setNextInterrupt(t.getCurrentTick()+80);
- printf("-CNT: %llu , NEXT CHKPNT: %llu\n",t.getCurrentTick(),t.getNextInterrupt());
-
+static void t1Task(void* p){
+ while (true){
+ IRQbootlog("1\r\n");
+ Thread::sleep(1000);
}
}
int main(){
- iprintf("Context Switch Timer Driver Test1 (80)\n");
-
- //basicTests(); //passed
- rightAfterCurrentTime();
+ //ContextSwitchTimer::instance();
+ Thread::setPriority(1);
+ printf("Context Switch Timer ....T=1ms\n");
+ Thread *p=Thread::create(t1Task,512,1,NULL);
+ while (true){
+ IRQbootlog("0\r\n");
+ Thread::sleep(250);
+ }
}
diff --git a/cstimer.cpp b/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/cstimer.cpp
similarity index 63%
rename from cstimer.cpp
rename to miosix/arch/cortexM4_stm32f4/common/interfaces-impl/cstimer.cpp
index 600f84f6..e2c2f80d 100644
--- a/cstimer.cpp
+++ b/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/cstimer.cpp
@@ -1,5 +1,6 @@
#include "miosix.h"
-#include "cstimer.h"
+#include "interfaces/cstimer.h"
+#include "interfaces/portability.h"
#include "kernel/logging.h"
#include <cstdlib>
using namespace miosix;
@@ -7,7 +8,14 @@ using namespace miosix;
static long long cst_ms32time = 0; //most significant 32 bits of counter
static long long cst_ms32chkp = 0; //most significant 32 bits of check point
static volatile bool cst_chkProcessed;
+static long long cst_prevChk;
+
+#define CST_QUANTOM 84000
#define CST_ROLLOVER_INT (TIM2->SR & TIM_SR_UIF) && (TIM2->SR & TIM_SR_CC2IF)
+
+namespace miosix_private{
+ void ISR_preempt();
+}
ContextSwitchTimer& ContextSwitchTimer::instance() {
static ContextSwitchTimer _instance;
return _instance;
@@ -18,7 +26,7 @@ ContextSwitchTimer::ContextSwitchTimer() {
* TIM2 Source Clock (from APB1) Enable
*/
{
- FastInterruptDisableLock idl;
+ InterruptDisableLock idl;
RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
RCC_SYNC();
}
@@ -33,10 +41,10 @@ ContextSwitchTimer::ContextSwitchTimer() {
TIM2->CCR3=0;
TIM2->CCR4=0;
TIM2->DIER=TIM_DIER_UIE | TIM_DIER_CC1IE;
- NVIC_SetPriority(TIM2_IRQn,1); //TO-DO: WHICH IRQ Priority to use? 0?
+ NVIC_SetPriority(TIM2_IRQn,3);
NVIC_EnableIRQ(TIM2_IRQn);
/*
- * Configure channel 1 as:
+ * Configure channel 1 as:
* Output channel (CC1S=0)
* No preload(OC1PE=0), hence TIM2_CCR1 can be written at anytime
* No effect on the output signal on match (OC1M = 0)
@@ -44,24 +52,21 @@ ContextSwitchTimer::ContextSwitchTimer() {
TIM2->CCMR1 = 0;
TIM2->CCR1 = 0;
/*
- * TIM2 Operation Frequency Configuration
+ * TIM2 Operation Frequency Configuration: Max Freq. and longest period
*/
- uint32_t pcsfreq = SystemCoreClock;
- uint32_t apb1_div = (RCC->CFGR & RCC_CFGR_PPRE1)>>10;
- //True assumption: AHB frequency is not divided :D
- if (apb1_div & 0x4) //APB1 Divider is active
- pcsfreq /= ((apb1_div & 0x3)+1)<<1;
-
TIM2->PSC = 0;
TIM2->ARR = 0xFFFFFFFF;
//printf("PSCFreq: %lu PCS: %lu ARR: %lu CCR1: %lu SR: %lu CNT: %lu\n",pcsfreq,TIM2->PSC,TIM2->ARR,TIM2->CCR1,TIM2->SR,TIM2->CNT);
/*
* Other initializations
*/
+ // Set the first checkpoint interrupt
+ cst_prevChk = CST_QUANTOM;
+ setNextInterrupt(cst_prevChk);
// Enable TIM2 Counter
+ cst_ms32time = 0;
TIM2->EGR = TIM_EGR_UG; //To enforce the timer to apply PSC (and other non-immediate settings)
TIM2->CR1 |= TIM_CR1_CEN;
- cst_ms32time = 0;
}
long long ContextSwitchTimer::getCurrentTick() {
@@ -70,7 +75,7 @@ long long ContextSwitchTimer::getCurrentTick() {
//If overflow occurs while interrupts disabled
/*
* counter should be checked before rollover interrupt flag
- *
+ *
*/
uint32_t counter = TIM2->CNT;
if (CST_ROLLOVER_INT && counter < 0x80000000){
@@ -87,6 +92,7 @@ void ContextSwitchTimer::setNextInterrupt(long long tick) {
cst_ms32chkp = tick & 0xFFFFFFFF00000000;
TIM2->CCR1 = (uint32_t)(tick & 0xFFFFFFFF);
cst_chkProcessed = false;
+ //if (getCurrentTick() > getNextInterrupt()) IRQbootlog("TIM2 - CHECK POINT SET IN THE PAST\r\n");
}
long long ContextSwitchTimer::getNextInterrupt(){
@@ -94,26 +100,35 @@ long long ContextSwitchTimer::getNextInterrupt(){
}
void __attribute__((used)) cstirqhnd(){
- if ((TIM2->SR & TIM_SR_CC1IF) && (cst_ms32time==cst_ms32chkp)){
+ //IRQbootlog("TIM2-IRQ\r\n");
+ if (TIM2->SR & TIM_SR_CC1IF){
//Checkpoint met
+ //The interrupt flag must be cleared unconditionally whether we are in the
+ //correct epoch or not otherwise the interrupt will happen even in unrelated
+ //epochs and slowing down the whole system.
TIM2->SR = ~TIM_SR_CC1IF;
- IRQbootlog(" (CHK POINT) \r\n");
- cst_chkProcessed = true;
-
+ if(cst_ms32time==cst_ms32chkp){
+ //Set next checkpoint interrupt
+ ////cst_prevChk += CST_QUANTOM;
+ ////ContextSwitchTimer::instance().setNextInterrupt(cst_prevChk);
+ ContextSwitchTimer::instance().setNextInterrupt(
+ ContextSwitchTimer::instance().getCurrentTick() + CST_QUANTOM);
+ cst_chkProcessed = true;
+ //Call preempt routine
+ miosix_private::ISR_preempt();
+ }
+
}
- if (CST_ROLLOVER_INT){
- //Rollover (Update and CC2 that is always set on zero)
- //On the initial update SR = UIF (ONLY)
+ //Rollover (Update and CC2 that is always set on zero)
+ //On the initial update SR = UIF (ONLY)
+ if (TIM2->SR & TIM_SR_UIF){
TIM2->SR = ~TIM_SR_UIF; //w0 clear
- IRQbootlog(" (ROLLOVER) \r\n");
- cst_ms32time += 0x100000000;
-
+ if (TIM2->SR & TIM_SR_CC2IF){
+ TIM2->SR = ~TIM_SR_CC2IF;
+ //IRQbootlog(" (ROLLOVER) \r\n");
+ cst_ms32time += 0x100000000;
+ }
}
- /*
- if (!cst_chkProcessed && cst_ms32chkp < (cst_ms32time | TIM2->CNT) && cst_ms32time==cst_ms32chkp){
- IRQbootlog(" (CHK POINT) \r\n");
- cst_chkProcessed = true;
- }*/
}
void __attribute__((naked)) TIM2_IRQHandler(){
diff --git a/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/portability.cpp b/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/portability.cpp
index 1f4cc55f..9f1884b8 100644
--- a/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/portability.cpp
+++ b/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/portability.cpp
@@ -38,6 +38,8 @@
#include <cstdio>
#include <cstring>
#include <cassert>
+#include "interfaces/cstimer.h"
+//#define CNTX_SWITCH_USE_SYSTICK
/**
* \internal
@@ -49,10 +51,12 @@
void SysTick_Handler() __attribute__((naked));
void SysTick_Handler()
{
+#ifdef CNTX_SWITCH_USE_SYSTICK
saveContext();
//Call ISR_preempt(). Name is a C++ mangled name.
asm volatile("bl _ZN14miosix_private11ISR_preemptEv");
restoreContext();
+#endif
}
/**
@@ -304,9 +308,13 @@ void IRQportableStartKernel()
NVIC_SetPriority(SVCall_IRQn,3);//High priority for SVC (Max=0, min=15)
NVIC_SetPriority(SysTick_IRQn,3);//High priority for SysTick (Max=0, min=15)
NVIC_SetPriority(MemoryManagement_IRQn,2);//Higher priority for MemoryManagement (Max=0, min=15)
+#ifdef CNTX_SWITCH_USE_SYSTICK
SysTick->LOAD=SystemCoreClock/miosix::TICK_FREQ;
SysTick->CTRL=SysTick_CTRL_ENABLE_Msk | SysTick_CTRL_TICKINT_Msk |
SysTick_CTRL_CLKSOURCE_Msk;
+#else //USE ContextSwitchTimer class (TIM2)
+ miosix::ContextSwitchTimer::instance();
+#endif
#ifdef WITH_PROCESSES
miosix::IRQenableMPUatBoot();
#endif //WITH_PROCESSES
diff --git a/miosix/config/Makefile.inc b/miosix/config/Makefile.inc
index 62737f90..39452470 100644
--- a/miosix/config/Makefile.inc
+++ b/miosix/config/Makefile.inc
@@ -1737,6 +1737,7 @@ else ifeq ($(ARCH),cortexM4_stm32f4)
$(ARCH_INC)/interfaces-impl/portability.cpp \
$(ARCH_INC)/interfaces-impl/delays.cpp \
$(ARCH_INC)/interfaces-impl/gpio_impl.cpp \
+ $(ARCH_INC)/interfaces-impl/cstimer.cpp \
arch/common/drivers/sd_stm32f2_f4.cpp \
arch/common/CMSIS/Device/ST/STM32F4xx/Source/Templates/system_stm32f4xx.c
diff --git a/cstimer.h b/miosix/interfaces/cstimer.h
similarity index 89%
rename from cstimer.h
rename to miosix/interfaces/cstimer.h
index 8b9491cb..3da5d860 100644
--- a/cstimer.h
+++ b/miosix/interfaces/cstimer.h
@@ -9,7 +9,7 @@ namespace miosix{
long long getNextInterrupt();
/**
* Could be call both when the interrupts are enabled/disabled!
- * @return
+ * @return the current tick count of the timer
*/
long long getCurrentTick();
virtual ~ContextSwitchTimer();
--
GitLab