/* FreeRTOS V9.0.0 - Copyright (C) 2016 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. This file is part of the FreeRTOS distribution. FreeRTOS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License (version 2) as published by the Free Software Foundation >>>> AND MODIFIED BY <<<< the FreeRTOS exception. *************************************************************************** >>! NOTE: The modification to the GPL is included to allow you to !<< >>! distribute a combined work that includes FreeRTOS without being !<< >>! obliged to provide the source code for proprietary components !<< >>! outside of the FreeRTOS kernel. !<< *************************************************************************** FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Full license text is available on the following link: http://www.freertos.org/a00114.html *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that is more than just the market leader, it * * is the industry's de facto standard. * * * * Help yourself get started quickly while simultaneously helping * * to support the FreeRTOS project by purchasing a FreeRTOS * * tutorial book, reference manual, or both: * * http://www.FreeRTOS.org/Documentation * * * *************************************************************************** http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading the FAQ page "My application does not run, what could be wrong?". Have you defined configASSERT()? http://www.FreeRTOS.org/support - In return for receiving this top quality embedded software for free we request you assist our global community by participating in the support forum. http://www.FreeRTOS.org/training - Investing in training allows your team to be as productive as possible as early as possible. Now you can receive FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers Ltd, and the world's leading authority on the world's leading RTOS. http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, including FreeRTOS+Trace - an indispensable productivity tool, a DOS compatible FAT file system, and our tiny thread aware UDP/IP stack. http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate. Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and commercial middleware. http://www.SafeRTOS.com - High Integrity Systems also provide a safety engineered and independently SIL3 certified version for use in safety and mission critical applications that require provable dependability. 1 tab == 4 spaces! */ #include "FreeRTOS.h" #include "task.h" #include "fsl_tickless_generic.h" #if configUSE_TICKLESS_IDLE == 1 #include "fsl_lptmr.h" #endif extern uint32_t SystemCoreClock; /* in Kinetis SDK, this contains the system core clock speed */ /* * LPT timer base address and interrupt number */ #if configUSE_TICKLESS_IDLE == 1 extern LPTMR_Type *vPortGetLptrmBase(void); extern IRQn_Type vPortGetLptmrIrqn(void); #endif /* configUSE_TICKLESS_IDLE */ /* * The number of SysTick increments that make up one tick period. */ #if configUSE_TICKLESS_IDLE == 1 static uint32_t ulTimerCountsForOneTick = 0; #endif /* configUSE_TICKLESS_IDLE */ /* * The maximum number of tick periods that can be suppressed is limited by the * 24 bit resolution of the SysTick timer. */ #if configUSE_TICKLESS_IDLE == 1 static uint32_t xMaximumPossibleSuppressedTicks = 0; #endif /* configUSE_TICKLESS_IDLE */ /* * The number of LPTIMER increments that make up one tick period. */ #if configUSE_TICKLESS_IDLE == 1 static uint32_t ulLPTimerCountsForOneTick = 0; #endif /* configUSE_TICKLESS_IDLE */ /* * The flag of LPTIMER is occurs or not. */ #if configUSE_TICKLESS_IDLE == 1 static volatile bool ulLPTimerInterruptFired = false; #endif /* configUSE_TICKLESS_IDLE */ #if configUSE_TICKLESS_IDLE == 1 void vPortLptmrIsr(void) { ulLPTimerInterruptFired = true; LPTMR_ClearStatusFlags(vPortGetLptrmBase(), kLPTMR_TimerCompareFlag); } void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime ) { uint32_t ulReloadValue, ulCompleteTickPeriods; TickType_t xModifiableIdleTime; LPTMR_Type *pxLptmrBase; pxLptmrBase = vPortGetLptrmBase(); if (pxLptmrBase == 0) return; /* Make sure the SysTick reload value does not overflow the counter. */ if( xExpectedIdleTime > xMaximumPossibleSuppressedTicks ) { xExpectedIdleTime = xMaximumPossibleSuppressedTicks; } if (xExpectedIdleTime == 0) return; /* Calculate the reload value required to wait xExpectedIdleTime tick periods. -1 is used because this code will execute part way through one of the tick periods. */ ulReloadValue = LPTMR_GetCurrentTimerCount(pxLptmrBase) + ( ulLPTimerCountsForOneTick * ( xExpectedIdleTime - 1UL ) ); /* Stop the LPTMR and systick momentarily. The time the LPTMR and systick is stopped for is accounted for as best it can be, but using the tickless mode will inevitably result in some tiny drift of the time maintained by the kernel with respect to calendar time. */ LPTMR_StopTimer(pxLptmrBase); portNVIC_SYSTICK_CTRL_REG &= ~portNVIC_SYSTICK_ENABLE_BIT; /* Enter a critical section but don't use the taskENTER_CRITICAL() method as that will mask interrupts that should exit sleep mode. */ __asm volatile( "cpsid i" ); __asm volatile( "dsb" ); __asm volatile( "isb" ); /* If a context switch is pending or a task is waiting for the scheduler to be unsuspended then abandon the low power entry. */ if( eTaskConfirmSleepModeStatus() == eAbortSleep ) { /* Restart from whatever is left in the count register to complete this tick period. */ portNVIC_SYSTICK_LOAD_REG = portNVIC_SYSTICK_CURRENT_VALUE_REG; /* Restart SysTick. */ portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT; /* Reset the reload register to the value required for normal tick periods. */ portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL; /* Re-enable interrupts - see comments above the cpsid instruction() above. */ __asm volatile( "cpsie i" ); } else { /* Set the new reload value. */ LPTMR_SetTimerPeriod(pxLptmrBase, ulReloadValue); /* Enable LPTMR. */ LPTMR_StartTimer(pxLptmrBase); /* Sleep until something happens. configPRE_SLEEP_PROCESSING() can set its parameter to 0 to indicate that its implementation contains its own wait for interrupt or wait for event instruction, and so wfi should not be executed again. However, the original expected idle time variable must remain unmodified, so a copy is taken. */ xModifiableIdleTime = xExpectedIdleTime; configPRE_SLEEP_PROCESSING( xModifiableIdleTime ); if( xModifiableIdleTime > 0 ) { __asm volatile( "dsb" ); __asm volatile( "wfi" ); __asm volatile( "isb" ); } configPOST_SLEEP_PROCESSING( xExpectedIdleTime ); ulLPTimerInterruptFired = false; /* Re-enable interrupts - see comments above the cpsid instruction() above. */ __asm volatile( "cpsie i" ); __NOP(); if( ulLPTimerInterruptFired ) { /* The tick interrupt handler will already have pended the tick processing in the kernel. As the pending tick will be processed as soon as this function exits, the tick value maintained by the tick is stepped forward by one less than the time spent waiting. */ ulCompleteTickPeriods = xExpectedIdleTime - 1UL; ulLPTimerInterruptFired = false; } else { /* Something other than the tick interrupt ended the sleep. Work out how long the sleep lasted rounded to complete tick periods (not the ulReload value which accounted for part ticks). */ ulCompleteTickPeriods = LPTMR_GetCurrentTimerCount(pxLptmrBase)/ulLPTimerCountsForOneTick; } /* Stop LPTMR when CPU waked up then set portNVIC_SYSTICK_LOAD_REG back to its standard value. The critical section is used to ensure the tick interrupt can only execute once in the case that the reload register is near zero. */ LPTMR_StopTimer(pxLptmrBase); portENTER_CRITICAL(); { portNVIC_SYSTICK_CTRL_REG |= portNVIC_SYSTICK_ENABLE_BIT; vTaskStepTick( ulCompleteTickPeriods ); portNVIC_SYSTICK_LOAD_REG = ulTimerCountsForOneTick - 1UL; } portEXIT_CRITICAL(); } } #endif /* #if configUSE_TICKLESS_IDLE */ /* * Setup the systick timer to generate the tick interrupts at the required * frequency. */ void vPortSetupTimerInterrupt( void ) { /* Calculate the constants required to configure the tick interrupt. */ #if( configUSE_TICKLESS_IDLE == 1 ) { ulTimerCountsForOneTick = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ); ulLPTimerCountsForOneTick = ( configLPTMR_CLOCK_HZ / configTICK_RATE_HZ ); xMaximumPossibleSuppressedTicks = portMAX_16_BIT_NUMBER / ulLPTimerCountsForOneTick; NVIC_EnableIRQ(vPortGetLptmrIrqn()); } #endif /* configUSE_TICKLESS_IDLE */ /* Configure SysTick to interrupt at the requested rate. */ portNVIC_SYSTICK_LOAD_REG = ( configSYSTICK_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL; portNVIC_SYSTICK_CURRENT_VALUE_REG = 0UL; portNVIC_SYSTICK_CTRL_REG = ( portNVIC_SYSTICK_CLK_BIT | portNVIC_SYSTICK_INT_BIT | portNVIC_SYSTICK_ENABLE_BIT ); }