FreeCalypso > hg > fc-tourmaline
view src/cs/drivers/drv_core/timer/timer.c @ 220:0ed36de51973
ABB semaphore protection overhaul
The ABB semaphone protection logic that came with TCS211 from TI
was broken in several ways:
* Some semaphore-protected functions were called from Application_Initialize()
context. NU_Obtain_Semaphore() called with NU_SUSPEND fails with
NU_INVALID_SUSPEND in this context, but the return value wasn't checked,
and NU_Release_Semaphore() would be called unconditionally at the end.
The latter call would increment the semaphore count past 1, making the
semaphore no longer binary and thus no longer effective for resource
protection. The fix is to check the return value from NU_Obtain_Semaphore()
and skip the NU_Release_Semaphore() call if the semaphore wasn't properly
obtained.
* Some SPI hardware manipulation was being done before entering the semaphore-
protected critical section. The fix is to reorder the code: first obtain
the semaphore, then do everything else.
* In the corner case of L1/DSP recovery, l1_abb_power_on() would call some
non-semaphore-protected ABB & SPI init functions. The fix is to skip those
calls in the case of recovery.
* A few additional corner cases existed, all of which are fixed by making
ABB semaphore protection 100% consistent for all ABB functions and code paths.
There is still one remaining problem of priority inversion: suppose a low-
priority task calls an ABB function, and some medium-priority task just happens
to preempt right in the middle of that semaphore-protected ABB operation. Then
the high-priority SPI task is locked out for a non-deterministic time until
that medium-priority task finishes its work and goes back to sleep. This
priority inversion problem remains outstanding for now.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 26 Apr 2021 20:55:25 +0000 |
parents | 4e78acac3d88 |
children |
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/******************************************************************************* TEXAS INSTRUMENTS INCORPORATED PROPRIETARY INFORMATION Property of Texas Instruments -- For Unrestricted Internal Use Only Unauthorized reproduction and/or distribution is strictly prohibited. This product is protected under copyright law and trade secret law as an unpublished work. Created 1987, (C) Copyright 1997 Texas Instruments. All rights reserved. Filename : timer.c Description : timer.c Project : drivers Author : pmonteil@tif.ti.com Patrice Monteil. Version number : 1.3 Date and time : 07/23/98 16:25:32 Previous delta : 07/23/98 16:25:32 SCCS file : /db/gsm_asp/db_ht96/dsp_0/gsw/rel_0/mcu_l1/release1.5/mod/emu/EMU_MCMP/eva3_drivers/source/SCCS/s.timer.c Sccs Id (SID) : '@(#) timer.c 1.3 07/23/98 16:25:32 ' *****************************************************************************/ #include "l1sw.cfg" #if (OP_L1_STANDALONE == 0) #include "main/sys_types.h" #else #include "sys_types.h" #endif #include "memif/mem.h" #include "inth/iq.h" #include "timer.h" /*-------------------------------------------------------------- * TIMER_Read() *-------------------------------------------------------------- * Parameters : num of the register to be read * Return :value of the timer register read * Functionality : read one of the TIMER register *--------------------------------------------------------------*/ SYS_UWORD16 TIMER_Read (unsigned short regNum) { volatile SYS_UWORD16 timerReg; switch (regNum) { case 0: timerReg = (( * (SYS_UWORD16 *) TIMER_CNTL_REG) & TIMER_CNTL_MASK); break; case 1: timerReg = ( * (SYS_UWORD16 *) TIMER_READ_REG); break; case 2: timerReg = (( * (SYS_UWORD16 *) TIMER_MODE_REG) & TIMER_MODE_MASK); break; default: break; } return(timerReg); } /*-------------------------------------------------------------- * TM_ResetTimer() *-------------------------------------------------------------- * Parameters : timer number (1 or 2) * timer value, reload yes or not, scale * Return : none * Functionality : Give the timewr state *--------------------------------------------------------------*/ void TM_ResetTimer (SYS_UWORD16 timerNum, SYS_UWORD16 countValue, SYS_UWORD16 autoReload, SYS_UWORD16 clockScale) { volatile SYS_UWORD16 *cntl; if (timerNum == 1) { cntl = (volatile SYS_UWORD16 *) TIMER1_CNTL; *cntl &= ~(START_STOP | PTV); /* stop and reset values */ (autoReload) ? (*cntl |= AR) : (*cntl &= ~AR); *cntl |= (clockScale << 2 ); * (SYS_UWORD16 *) TIMER1_LOAD_TIM = countValue; /*load the value */ *cntl |= START_STOP; } else { cntl = (volatile SYS_UWORD16 *) TIMER2_CNTL; *cntl &= ~(START_STOP | PTV); /* stop and reset values */ (autoReload) ? (*cntl |= AR) : (*cntl &= ~AR); *cntl |= (clockScale << 2 ); * (SYS_UWORD16 *) TIMER2_LOAD_TIM = countValue; /*load the value */ *cntl |= START_STOP; } } /* * TM_StopTimer * * Parameters : timer number (1 or 2) */ void TM_StopTimer (int timerNum) { volatile SYS_UWORD16 *cntl; if (timerNum == 1) { cntl = (volatile SYS_UWORD16 *) TIMER1_CNTL; } else { cntl = (volatile SYS_UWORD16 *) TIMER2_CNTL; } *cntl &= ~START_STOP; } /* * TM_ReadTimer * * Returns current timer value * * Parameters : timer number (1 or 2) * */ SYS_UWORD16 TM_ReadTimer (int timerNum) { if (timerNum == 1) { return (* (SYS_UWORD16 *) TIMER1_READ_TIM); } else { return (* (SYS_UWORD16 *) TIMER2_READ_TIM); } } /* * TM_StartTimer * * Parameters : timer number (1 or 2) * */ void TM_StartTimer (int timerNum) { volatile SYS_UWORD16 *cntl; if (timerNum == 1) { cntl = (volatile SYS_UWORD16 *) TIMER1_CNTL; } else { cntl = (volatile SYS_UWORD16 *) TIMER2_CNTL; } *cntl |= START_STOP; } void TM_DisableWatchdog (void) { /* volatile variable needed due C to optimization */ volatile SYS_UWORD16 *reg = (volatile SYS_UWORD16 *) TIMER_MODE_REG; *reg = 0xf5; *reg = 0xa0; } /* * TM_EnableWatchdog * */ void TM_EnableWatchdog(void) { * ((volatile SYS_UWORD16 *) TIMER_MODE_REG) = TIMER_WDOG; } /* * TM_ResetWatchdog * * Parameter : Tick count * Use a different value each time, otherwise watchdog bites */ void TM_ResetWatchdog(SYS_UWORD16 count) { * ((volatile SYS_UWORD16 *) TIMER_LOAD_REG) = count; } /* * TM_EnableTimer (int TimerNum) * * Parameter : TimerNum : timer to enable (timer1 or timer2) * */ void TM_EnableTimer (int TimerNum) { volatile SYS_UWORD16 *cntl; if (TimerNum == 1) { cntl = (volatile SYS_UWORD16 *) TIMER1_CNTL; } else { cntl = (volatile SYS_UWORD16 *) TIMER2_CNTL; } *cntl |= TIMER_CLK_EN; } /* * TM_DisableTimer (int TimerNum) * * Parameter : TimerNum : timer to enable (timer1 or timer2) * */ void TM_DisableTimer (int TimerNum) { volatile SYS_UWORD16 *cntl; if (TimerNum == 1) { cntl = (volatile SYS_UWORD16 *) TIMER1_CNTL; } else { cntl = (volatile SYS_UWORD16 *) TIMER2_CNTL; } *cntl &= ~TIMER_CLK_EN; } /*-------------------------------------------------------------- * TIMER_ReadValue() *-------------------------------------------------------------- * Parameters : none * Return : none * Functionality : Read timer value *--------------------------------------------------------------*/ unsigned short TIMER_ReadValue (void) { return(* (SYS_UWORD16 *) TIMER_READ_REG); } /*-------------------------------------------------------------- * TIMER_WriteValue() *-------------------------------------------------------------- * Parameters : none * Return : none * Functionality : Write timer value *--------------------------------------------------------------*/ void TIMER_WriteValue (SYS_UWORD16 value) { * (SYS_UWORD16 *) TIMER_LOAD_REG = value; /*load the value */ }