tbitimer.S
/*
* tbitimer.S
*
* Copyright (C) 2001, 2002, 2007, 2012 Imagination Technologies.
*
* This program 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.
*
* TBI timer support routines and data values
*/
.file "tbitimer.S"
/*
* Get data structures and defines from the main C header
*/
#include <asm/tbx.h>
.data
.balign 8
.global ___TBITimeB
.type ___TBITimeB,object
___TBITimeB:
.quad 0 /* Background 'lost' ticks */
.size ___TBITimeB,.-___TBITimeB
.data
.balign 8
.global ___TBITimeI
.type ___TBITimeI,object
___TBITimeI:
.quad 0 /* Interrupt 'lost' ticks */
.size ___TBITimeI,.-___TBITimeI
.data
.balign 8
.global ___TBITimes
.type ___TBITimes,object
___TBITimes:
.long ___TBITimeB /* Table of 'lost' tick values */
.long ___TBITimeI
.size ___TBITimes,.-___TBITimes
/*
* Flag bits for control of ___TBITimeCore
*/
#define TIMER_SET_BIT 1
#define TIMER_ADD_BIT 2
/*
* Initialise or stop timer support
*
* Register Usage: D1Ar1 holds Id, D1Ar2 is initial delay or 0
* D0FrT is used to call ___TBITimeCore
* D0Re0 is used for the result which is TXSTAT_TIMER_BIT
* D0Ar4, D1Ar5, D0Ar6 are all used as scratch
* Other registers are those set by ___TBITimeCore
* A0.3 is assumed to point at ___TBITime(I/B)
*/
.text
.balign 4
.global ___TBITimerCtrl
.type ___TBITimerCtrl,function
___TBITimerCtrl:
MOV D1Ar5,#TIMER_SET_BIT /* Timer SET request */
MOVT D0FrT,#HI(___TBITimeCore) /* Get timer core reg values */
CALL D0FrT,#LO(___TBITimeCore) /* and perform register update */
NEGS D0Ar6,D0Ar2 /* Set flags from time-stamp */
ASR D1Ar5,D0Ar6,#31 /* Sign extend D0Ar6 into D1Ar5 */
SETLNZ [A0.3],D0Ar6,D1Ar5 /* ___TBITime(B/I)=-Start if enable */
MOV PC,D1RtP /* Return */
.size ___TBITimerCtrl,.-___TBITimerCtrl
/*
* Return ___TBITimeStamp value
*
* Register Usage: D1Ar1 holds Id
* D0FrT is used to call ___TBITimeCore
* D0Re0, D1Re0 is used for the result
* D1Ar3, D0Ar4, D1Ar5
* Other registers are those set by ___TBITimeCore
* D0Ar6 is assumed to be the timer value read
* A0.3 is assumed to point at ___TBITime(I/B)
*/
.text
.balign 4
.global ___TBITimeStamp
.type ___TBITimeStamp,function
___TBITimeStamp:
MOV D1Ar5,#0 /* Timer GET request */
MOVT D0FrT,#HI(___TBITimeCore) /* Get timer core reg values */
CALL D0FrT,#LO(___TBITimeCore) /* with no register update */
ADDS D0Re0,D0Ar4,D0Ar6 /* Add current time value */
ADD D1Re0,D1Ar3,D1Ar5 /* to 64-bit signed extend time */
ADDCS D1Re0,D1Re0,#1 /* Support borrow too */
MOV PC,D1RtP /* Return */
.size ___TBITimeStamp,.-___TBITimeStamp
/*
* Perform ___TBITimerAdd logic
*
* Register Usage: D1Ar1 holds Id, D0Ar2 holds value to be added to the timer
* D0Re0 is used for the result - new TIMER value
* D1Ar5, D0Ar6 are used as scratch
* Other registers are those set by ___TBITimeCore
* D0Ar6 is assumed to be the timer value read
* D0Ar4, D1Ar3 is the current value of ___TBITime(B/I)
*/
.text
.balign 4
.global ___TBITimerAdd
.type ___TBITimerAdd,function
___TBITimerAdd:
MOV D1Ar5,#TIMER_ADD_BIT /* Timer ADD request */
MOVT D0FrT,#HI(___TBITimeCore) /* Get timer core reg values */
CALL D0FrT,#LO(___TBITimeCore) /* with no register update */
ADD D0Re0,D0Ar2,D0Ar6 /* Regenerate new value = result */
NEG D0Ar2,D0Ar2 /* Negate delta */
ASR D1Re0,D0Ar2,#31 /* Sign extend negated delta */
ADDS D0Ar4,D0Ar4,D0Ar2 /* Add time added to ... */
ADD D1Ar3,D1Ar3,D1Re0 /* ... real timer ... */
ADDCS D1Ar3,D1Ar3,#1 /* ... with carry */
SETL [A0.3],D0Ar4,D1Ar3 /* Update ___TBITime(B/I) */
MOV PC,D1RtP /* Return */
.size ___TBITimerAdd,.-___TBITimerAdd
#ifdef TBI_1_4
/*
* Perform ___TBITimerDeadline logic
* NB: Delays are positive compared to the Wait values which are -ive
*
* Register Usage: D1Ar1 holds Id
* D0Ar2 holds Delay requested
* D0Re0 is used for the result - old TIMER Delay value
* D1Ar5, D0Ar6 are used as scratch
* Other registers are those set by ___TBITimeCore
* D0Ar6 is assumed to be the timer value read
* D0Ar4, D1Ar3 is the current value of ___TBITime(B/I)
*
*/
.text
.type ___TBITimerDeadline,function
.global ___TBITimerDeadline
.align 2
___TBITimerDeadline:
MOV D1Ar5,#TIMER_SET_BIT /* Timer SET request */
MOVT D0FrT,#HI(___TBITimeCore) /* Get timer core reg values */
CALL D0FrT,#LO(___TBITimeCore) /* with no register update */
MOV D0Re0,D0Ar6 /* Old value read = result */
SUB D0Ar2,D0Ar6,D0Ar2 /* Delta from (old - new) */
ASR D1Re0,D0Ar2,#31 /* Sign extend delta */
ADDS D0Ar4,D0Ar4,D0Ar2 /* Add time added to ... */
ADD D1Ar3,D1Ar3,D1Re0 /* ... real timer ... */
ADDCS D1Ar3,D1Ar3,#1 /* ... with carry */
SETL [A0.3],D0Ar4,D1Ar3 /* Update ___TBITime(B/I) */
MOV PC,D1RtP /* Return */
.size ___TBITimerDeadline,.-___TBITimerDeadline
#endif /* TBI_1_4 */
/*
* Perform core timer access logic
*
* Register Usage: D1Ar1 holds Id, D0Ar2 holds input value for SET and
* input value for ADD
* D1Ar5 controls op as SET or ADD as bit values
* On return D0Ar6, D1Ar5 holds the old 64-bit timer value
* A0.3 is setup to point at ___TBITime(I/B)
* A1.3 is setup to point at ___TBITimes
* D0Ar4, D1Ar3 is setup to value of ___TBITime(I/B)
*/
.text
.balign 4
.global ___TBITimeCore
.type ___TBITimeCore,function
___TBITimeCore:
#ifndef METAC_0_1
TSTT D1Ar1,#HI(TBID_ISTAT_BIT) /* Interrupt level timer? */
#endif
MOVT A1LbP,#HI(___TBITimes)
ADD A1LbP,A1LbP,#LO(___TBITimes)
MOV A1.3,A1LbP /* Get ___TBITimes address */
#ifndef METAC_0_1
BNZ $LTimeCoreI /* Yes: Service TXTIMERI! */
#endif
LSRS D1Ar5,D1Ar5,#1 /* Carry = SET, Zero = !ADD */
GETD A0.3,[A1.3+#0] /* A0.3 == &___TBITimeB */
MOV D0Ar6,TXTIMER /* Always GET old value */
MOVCS TXTIMER,D0Ar2 /* Conditional SET operation */
ADDNZ TXTIMER,D0Ar2,D0Ar6 /* Conditional ADD operation */
#ifndef METAC_0_1
B $LTimeCoreEnd
$LTimeCoreI:
LSRS D1Ar5,D1Ar5,#1 /* Carry = SET, Zero = !ADD */
GETD A0.3,[A1.3+#4] /* A0.3 == &___TBITimeI */
MOV D0Ar6,TXTIMERI /* Always GET old value */
MOVCS TXTIMERI,D0Ar2 /* Conditional SET operation */
ADDNZ TXTIMERI,D0Ar2,D0Ar6 /* Conditional ADD operation */
$LTimeCoreEnd:
#endif
ASR D1Ar5,D0Ar6,#31 /* Sign extend D0Ar6 into D1Ar5 */
GETL D0Ar4,D1Ar3,[A0.3] /* Read ___TBITime(B/I) */
MOV PC,D0FrT /* Return quickly */
.size ___TBITimeCore,.-___TBITimeCore
/*
* End of tbitimer.S
*/
