| /* | |
| * FreeRTOS Kernel V10.3.1 | |
| * Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved. | |
| * | |
| * Permission is hereby granted, free of charge, to any person obtaining a copy of | |
| * this software and associated documentation files (the "Software"), to deal in | |
| * the Software without restriction, including without limitation the rights to | |
| * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of | |
| * the Software, and to permit persons to whom the Software is furnished to do so, | |
| * subject to the following conditions: | |
| * | |
| * The above copyright notice and this permission notice shall be included in all | |
| * copies or substantial portions of the Software. | |
| * | |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS | |
| * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR | |
| * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER | |
| * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN | |
| * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
| * | |
| * http://www.FreeRTOS.org | |
| * http://aws.amazon.com/freertos | |
| * | |
| */ | |
| /*----------------------------------------------------------- | |
| * Implementation of functions defined in portable.h for the SH2A port. | |
| *----------------------------------------------------------*/ | |
| /* Standard C includes. */ | |
| #include "limits.h" | |
| /* Scheduler includes. */ | |
| #include "FreeRTOS.h" | |
| #include "task.h" | |
| /* Library includes. */ | |
| #include "string.h" | |
| /* Hardware specifics. */ | |
| #include "machine.h" | |
| /*-----------------------------------------------------------*/ | |
| /* Tasks should start with interrupts enabled and in Supervisor mode, therefore | |
| * PSW is set with U and I set, and PM and IPL clear. */ | |
| #define portINITIAL_PSW ( ( StackType_t ) 0x00030000 ) | |
| /* The peripheral clock is divided by this value before being supplying the | |
| * CMT. */ | |
| #if ( configUSE_TICKLESS_IDLE == 0 ) | |
| /* If tickless idle is not used then the divisor can be fixed. */ | |
| #define portCLOCK_DIVISOR 8UL | |
| #elif ( configPERIPHERAL_CLOCK_HZ >= 12000000 ) | |
| #define portCLOCK_DIVISOR 512UL | |
| #elif ( configPERIPHERAL_CLOCK_HZ >= 6000000 ) | |
| #define portCLOCK_DIVISOR 128UL | |
| #elif ( configPERIPHERAL_CLOCK_HZ >= 1000000 ) | |
| #define portCLOCK_DIVISOR 32UL | |
| #else | |
| #define portCLOCK_DIVISOR 8UL | |
| #endif | |
| /* Keys required to lock and unlock access to certain system registers | |
| * respectively. */ | |
| #define portUNLOCK_KEY 0xA50B | |
| #define portLOCK_KEY 0xA500 | |
| /*-----------------------------------------------------------*/ | |
| /* | |
| * Function to start the first task executing - written in asm code as direct | |
| * access to registers is required. | |
| */ | |
| extern void prvStartFirstTask( void ); | |
| /* | |
| * The tick ISR handler. The peripheral used is configured by the application | |
| * via a hook/callback function. | |
| */ | |
| __interrupt static void prvTickISR( void ); | |
| /* | |
| * Sets up the periodic ISR used for the RTOS tick using the CMT. | |
| * The application writer can define configSETUP_TICK_INTERRUPT() (in | |
| * FreeRTOSConfig.h) such that their own tick interrupt configuration is used | |
| * in place of prvSetupTimerInterrupt(). | |
| */ | |
| static void prvSetupTimerInterrupt( void ); | |
| #ifndef configSETUP_TICK_INTERRUPT | |
| /* The user has not provided their own tick interrupt configuration so use | |
| * the definition in this file (which uses the interval timer). */ | |
| #define configSETUP_TICK_INTERRUPT() prvSetupTimerInterrupt() | |
| #endif /* configSETUP_TICK_INTERRUPT */ | |
| /* | |
| * Called after the sleep mode registers have been configured, prvSleep() | |
| * executes the pre and post sleep macros, and actually calls the wait | |
| * instruction. | |
| */ | |
| #if configUSE_TICKLESS_IDLE == 1 | |
| static void prvSleep( TickType_t xExpectedIdleTime ); | |
| #endif /* configUSE_TICKLESS_IDLE */ | |
| /*-----------------------------------------------------------*/ | |
| extern void * pxCurrentTCB; | |
| /*-----------------------------------------------------------*/ | |
| /* Calculate how many clock increments make up a single tick period. */ | |
| static const uint32_t ulMatchValueForOneTick = ( ( configPERIPHERAL_CLOCK_HZ / portCLOCK_DIVISOR ) / configTICK_RATE_HZ ); | |
| #if configUSE_TICKLESS_IDLE == 1 | |
| /* Holds the maximum number of ticks that can be suppressed - which is | |
| * basically how far into the future an interrupt can be generated. Set | |
| * during initialisation. This is the maximum possible value that the | |
| * compare match register can hold divided by ulMatchValueForOneTick. */ | |
| static const TickType_t xMaximumPossibleSuppressedTicks = USHRT_MAX / ( ( configPERIPHERAL_CLOCK_HZ / portCLOCK_DIVISOR ) / configTICK_RATE_HZ ); | |
| /* Flag set from the tick interrupt to allow the sleep processing to know if | |
| * sleep mode was exited because of a tick interrupt, or an interrupt | |
| * generated by something else. */ | |
| static volatile uint32_t ulTickFlag = pdFALSE; | |
| /* The CMT counter is stopped temporarily each time it is re-programmed. | |
| * The following constant offsets the CMT counter match value by the number of | |
| * CMT counts that would typically be missed while the counter was stopped to | |
| * compensate for the lost time. The large difference between the divided CMT | |
| * clock and the CPU clock means it is likely ulStoppedTimerCompensation will | |
| * equal zero - and be optimised away. */ | |
| static const uint32_t ulStoppedTimerCompensation = 100UL / ( configCPU_CLOCK_HZ / ( configPERIPHERAL_CLOCK_HZ / portCLOCK_DIVISOR ) ); | |
| #endif /* if configUSE_TICKLESS_IDLE == 1 */ | |
| /*-----------------------------------------------------------*/ | |
| /* | |
| * See header file for description. | |
| */ | |
| StackType_t * pxPortInitialiseStack( StackType_t * pxTopOfStack, | |
| TaskFunction_t pxCode, | |
| void * pvParameters ) | |
| { | |
| /* Offset to end up on 8 byte boundary. */ | |
| pxTopOfStack--; | |
| /* R0 is not included as it is the stack pointer. */ | |
| *pxTopOfStack = 0x00; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x00; | |
| pxTopOfStack--; | |
| *pxTopOfStack = portINITIAL_PSW; | |
| pxTopOfStack--; | |
| *pxTopOfStack = ( StackType_t ) pxCode; | |
| /* When debugging it can be useful if every register is set to a known | |
| * value. Otherwise code space can be saved by just setting the registers | |
| * that need to be set. */ | |
| #ifdef USE_FULL_REGISTER_INITIALISATION | |
| { | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x12345678; /* r15. */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0xaaaabbbb; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0xdddddddd; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0xcccccccc; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0xbbbbbbbb; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0xaaaaaaaa; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x99999999; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x88888888; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x77777777; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x66666666; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x55555555; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x44444444; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x33333333; | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x22222222; | |
| pxTopOfStack--; | |
| } | |
| #else /* ifdef USE_FULL_REGISTER_INITIALISATION */ | |
| { | |
| /* Leave space for the registers that will get popped from the stack | |
| * when the task first starts executing. */ | |
| pxTopOfStack -= 15; | |
| } | |
| #endif /* ifdef USE_FULL_REGISTER_INITIALISATION */ | |
| *pxTopOfStack = ( StackType_t ) pvParameters; /* R1 */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x12345678; /* Accumulator. */ | |
| pxTopOfStack--; | |
| *pxTopOfStack = 0x87654321; /* Accumulator. */ | |
| return pxTopOfStack; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| BaseType_t xPortStartScheduler( void ) | |
| { | |
| /* Use pxCurrentTCB just so it does not get optimised away. */ | |
| if( pxCurrentTCB != NULL ) | |
| { | |
| /* Call an application function to set up the timer that will generate | |
| * the tick interrupt. This way the application can decide which | |
| * peripheral to use. If tickless mode is used then the default | |
| * implementation defined in this file (which uses CMT0) should not be | |
| * overridden. */ | |
| configSETUP_TICK_INTERRUPT(); | |
| /* Enable the software interrupt. */ | |
| _IEN( _ICU_SWINT ) = 1; | |
| /* Ensure the software interrupt is clear. */ | |
| _IR( _ICU_SWINT ) = 0; | |
| /* Ensure the software interrupt is set to the kernel priority. */ | |
| _IPR( _ICU_SWINT ) = configKERNEL_INTERRUPT_PRIORITY; | |
| /* Start the first task. */ | |
| prvStartFirstTask(); | |
| } | |
| /* Execution should not reach here as the tasks are now running! | |
| * prvSetupTimerInterrupt() is called here to prevent the compiler outputting | |
| * a warning about a statically declared function not being referenced in the | |
| * case that the application writer has provided their own tick interrupt | |
| * configuration routine (and defined configSETUP_TICK_INTERRUPT() such that | |
| * their own routine will be called in place of prvSetupTimerInterrupt()). */ | |
| prvSetupTimerInterrupt(); | |
| /* Should not get here. */ | |
| return pdFAIL; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| #pragma vector = configTICK_VECTOR | |
| __interrupt static void prvTickISR( void ) | |
| { | |
| /* Re-enable interrupts. */ | |
| __enable_interrupt(); | |
| /* Increment the tick, and perform any processing the new tick value | |
| * necessitates. */ | |
| __set_interrupt_level( configMAX_SYSCALL_INTERRUPT_PRIORITY ); | |
| { | |
| if( xTaskIncrementTick() != pdFALSE ) | |
| { | |
| taskYIELD(); | |
| } | |
| } | |
| __set_interrupt_level( configKERNEL_INTERRUPT_PRIORITY ); | |
| #if configUSE_TICKLESS_IDLE == 1 | |
| { | |
| /* The CPU woke because of a tick. */ | |
| ulTickFlag = pdTRUE; | |
| /* If this is the first tick since exiting tickless mode then the CMT | |
| * compare match value needs resetting. */ | |
| CMT0.CMCOR = ( uint16_t ) ulMatchValueForOneTick; | |
| } | |
| #endif | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vPortEndScheduler( void ) | |
| { | |
| /* Not implemented in ports where there is nothing to return to. | |
| * Artificially force an assert. */ | |
| configASSERT( pxCurrentTCB == NULL ); | |
| } | |
| /*-----------------------------------------------------------*/ | |
| static void prvSetupTimerInterrupt( void ) | |
| { | |
| /* Unlock. */ | |
| SYSTEM.PRCR.WORD = portUNLOCK_KEY; | |
| /* Enable CMT0. */ | |
| MSTP( CMT0 ) = 0; | |
| /* Lock again. */ | |
| SYSTEM.PRCR.WORD = portLOCK_KEY; | |
| /* Interrupt on compare match. */ | |
| CMT0.CMCR.BIT.CMIE = 1; | |
| /* Set the compare match value. */ | |
| CMT0.CMCOR = ( uint16_t ) ulMatchValueForOneTick; | |
| /* Divide the PCLK. */ | |
| #if portCLOCK_DIVISOR == 512 | |
| { | |
| CMT0.CMCR.BIT.CKS = 3; | |
| } | |
| #elif portCLOCK_DIVISOR == 128 | |
| { | |
| CMT0.CMCR.BIT.CKS = 2; | |
| } | |
| #elif portCLOCK_DIVISOR == 32 | |
| { | |
| CMT0.CMCR.BIT.CKS = 1; | |
| } | |
| #elif portCLOCK_DIVISOR == 8 | |
| { | |
| CMT0.CMCR.BIT.CKS = 0; | |
| } | |
| #else /* if portCLOCK_DIVISOR == 512 */ | |
| { | |
| #error Invalid portCLOCK_DIVISOR setting | |
| } | |
| #endif /* if portCLOCK_DIVISOR == 512 */ | |
| /* Enable the interrupt... */ | |
| _IEN( _CMT0_CMI0 ) = 1; | |
| /* ...and set its priority to the application defined kernel priority. */ | |
| _IPR( _CMT0_CMI0 ) = configKERNEL_INTERRUPT_PRIORITY; | |
| /* Start the timer. */ | |
| CMT.CMSTR0.BIT.STR0 = 1; | |
| } | |
| /*-----------------------------------------------------------*/ | |
| #if configUSE_TICKLESS_IDLE == 1 | |
| static void prvSleep( TickType_t xExpectedIdleTime ) | |
| { | |
| /* Allow the application to define some pre-sleep processing. */ | |
| configPRE_SLEEP_PROCESSING( xExpectedIdleTime ); | |
| /* xExpectedIdleTime being set to 0 by configPRE_SLEEP_PROCESSING() | |
| * means the application defined code has already executed the WAIT | |
| * instruction. */ | |
| if( xExpectedIdleTime > 0 ) | |
| { | |
| __wait_for_interrupt(); | |
| } | |
| /* Allow the application to define some post sleep processing. */ | |
| configPOST_SLEEP_PROCESSING( xExpectedIdleTime ); | |
| } | |
| #endif /* configUSE_TICKLESS_IDLE */ | |
| /*-----------------------------------------------------------*/ | |
| #if configUSE_TICKLESS_IDLE == 1 | |
| void vPortSuppressTicksAndSleep( TickType_t xExpectedIdleTime ) | |
| { | |
| uint32_t ulMatchValue, ulCompleteTickPeriods, ulCurrentCount; | |
| eSleepModeStatus eSleepAction; | |
| /* THIS FUNCTION IS CALLED WITH THE SCHEDULER SUSPENDED. */ | |
| /* Make sure the CMT reload value does not overflow the counter. */ | |
| if( xExpectedIdleTime > xMaximumPossibleSuppressedTicks ) | |
| { | |
| xExpectedIdleTime = xMaximumPossibleSuppressedTicks; | |
| } | |
| /* Calculate the reload value required to wait xExpectedIdleTime tick | |
| * periods. */ | |
| ulMatchValue = ulMatchValueForOneTick * xExpectedIdleTime; | |
| if( ulMatchValue > ulStoppedTimerCompensation ) | |
| { | |
| /* Compensate for the fact that the CMT is going to be stopped | |
| * momentarily. */ | |
| ulMatchValue -= ulStoppedTimerCompensation; | |
| } | |
| /* Stop the CMT momentarily. The time the CMT 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. */ | |
| CMT.CMSTR0.BIT.STR0 = 0; | |
| while( CMT.CMSTR0.BIT.STR0 == 1 ) | |
| { | |
| /* Nothing to do here. */ | |
| } | |
| /* Critical section using the global interrupt bit as the i bit is | |
| * automatically reset by the WAIT instruction. */ | |
| __disable_interrupt(); | |
| /* The tick flag is set to false before sleeping. If it is true when | |
| * sleep mode is exited then sleep mode was probably exited because the | |
| * tick was suppressed for the entire xExpectedIdleTime period. */ | |
| ulTickFlag = pdFALSE; | |
| /* If a context switch is pending then abandon the low power entry as | |
| * the context switch might have been pended by an external interrupt that | |
| * requires processing. */ | |
| eSleepAction = eTaskConfirmSleepModeStatus(); | |
| if( eSleepAction == eAbortSleep ) | |
| { | |
| /* Restart tick. */ | |
| CMT.CMSTR0.BIT.STR0 = 1; | |
| __enable_interrupt(); | |
| } | |
| else if( eSleepAction == eNoTasksWaitingTimeout ) | |
| { | |
| /* Protection off. */ | |
| SYSTEM.PRCR.WORD = portUNLOCK_KEY; | |
| /* Ready for software standby with all clocks stopped. */ | |
| SYSTEM.SBYCR.BIT.SSBY = 1; | |
| /* Protection on. */ | |
| SYSTEM.PRCR.WORD = portLOCK_KEY; | |
| /* Sleep until something happens. Calling prvSleep() will | |
| * automatically reset the i bit in the PSW. */ | |
| prvSleep( xExpectedIdleTime ); | |
| /* Restart the CMT. */ | |
| CMT.CMSTR0.BIT.STR0 = 1; | |
| } | |
| else | |
| { | |
| /* Protection off. */ | |
| SYSTEM.PRCR.WORD = portUNLOCK_KEY; | |
| /* Ready for deep sleep mode. */ | |
| SYSTEM.MSTPCRC.BIT.DSLPE = 1; | |
| SYSTEM.MSTPCRA.BIT.MSTPA28 = 1; | |
| SYSTEM.SBYCR.BIT.SSBY = 0; | |
| /* Protection on. */ | |
| SYSTEM.PRCR.WORD = portLOCK_KEY; | |
| /* Adjust the match value to take into account that the current | |
| * time slice is already partially complete. */ | |
| ulMatchValue -= ( uint32_t ) CMT0.CMCNT; | |
| CMT0.CMCOR = ( uint16_t ) ulMatchValue; | |
| /* Restart the CMT to count up to the new match value. */ | |
| CMT0.CMCNT = 0; | |
| CMT.CMSTR0.BIT.STR0 = 1; | |
| /* Sleep until something happens. Calling prvSleep() will | |
| * automatically reset the i bit in the PSW. */ | |
| prvSleep( xExpectedIdleTime ); | |
| /* Stop CMT. Again, the time the 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. */ | |
| CMT.CMSTR0.BIT.STR0 = 0; | |
| while( CMT.CMSTR0.BIT.STR0 == 1 ) | |
| { | |
| /* Nothing to do here. */ | |
| } | |
| ulCurrentCount = ( uint32_t ) CMT0.CMCNT; | |
| if( ulTickFlag != pdFALSE ) | |
| { | |
| /* The tick interrupt has already executed, although because | |
| * this function is called with the scheduler suspended the actual | |
| * tick processing will not occur until after this function has | |
| * exited. Reset the match value with whatever remains of this | |
| * tick period. */ | |
| ulMatchValue = ulMatchValueForOneTick - ulCurrentCount; | |
| CMT0.CMCOR = ( uint16_t ) ulMatchValue; | |
| /* 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 sleeping. The actual stepping of the tick appears | |
| * later in this function. */ | |
| ulCompleteTickPeriods = xExpectedIdleTime - 1UL; | |
| } | |
| else | |
| { | |
| /* Something other than the tick interrupt ended the sleep. | |
| * How many complete tick periods passed while the processor was | |
| * sleeping? */ | |
| ulCompleteTickPeriods = ulCurrentCount / ulMatchValueForOneTick; | |
| /* The match value is set to whatever fraction of a single tick | |
| * period remains. */ | |
| ulMatchValue = ulCurrentCount - ( ulCompleteTickPeriods * ulMatchValueForOneTick ); | |
| CMT0.CMCOR = ( uint16_t ) ulMatchValue; | |
| } | |
| /* Restart the CMT so it runs up to the match value. The match value | |
| * will get set to the value required to generate exactly one tick period | |
| * the next time the CMT interrupt executes. */ | |
| CMT0.CMCNT = 0; | |
| CMT.CMSTR0.BIT.STR0 = 1; | |
| /* Wind the tick forward by the number of tick periods that the CPU | |
| * remained in a low power state. */ | |
| vTaskStepTick( ulCompleteTickPeriods ); | |
| } | |
| } | |
| #endif /* configUSE_TICKLESS_IDLE */ |