[mirror_ubuntu-artful-kernel.git] / drivers / staging / epl / TimerHighReskX86.c

/****************************************************************************

  (c) SYSTEC electronic GmbH, D-07973 Greiz, August-Bebel-Str. 29
      www.systec-electronic.com

  Project:      openPOWERLINK

  Description:  target specific implementation of
                high resolution timer module for X86 under Linux
                The Linux kernel has to be compiled with high resolution
                timers enabled. This is done by configuring the kernel
                with CONFIG_HIGH_RES_TIMERS enabled.

  License:

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.

    3. Neither the name of SYSTEC electronic GmbH nor the names of its
       contributors may be used to endorse or promote products derived
       from this software without prior written permission. For written
       permission, please contact info@systec-electronic.com.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

    Severability Clause:

        If a provision of this License is or becomes illegal, invalid or
        unenforceable in any jurisdiction, that shall not affect:
        1. the validity or enforceability in that jurisdiction of any other
           provision of this License; or
        2. the validity or enforceability in other jurisdictions of that or
           any other provision of this License.

  -------------------------------------------------------------------------

                $RCSfile: TimerHighReskX86.c,v $

                $Author: D.Krueger $

                $Revision: 1.4 $  $Date: 2008/04/17 21:38:01 $

                $State: Exp $

                Build Environment:
                    GNU

  -------------------------------------------------------------------------

  Revision History:

****************************************************************************/

#include "EplInc.h"
#include "kernel/EplTimerHighResk.h"
#include "Benchmark.h"

//#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/hrtimer.h>

/***************************************************************************/
/*                                                                         */
/*                                                                         */
/*          G L O B A L   D E F I N I T I O N S                            */
/*                                                                         */
/*                                                                         */
/***************************************************************************/

//---------------------------------------------------------------------------
// const defines
//---------------------------------------------------------------------------

#define TIMER_COUNT           2	/* max 15 timers selectable */
#define TIMER_MIN_VAL_SINGLE  5000	/* min 5us */
#define TIMER_MIN_VAL_CYCLE   100000	/* min 100us */

#define PROVE_OVERRUN

#ifndef CONFIG_HIGH_RES_TIMERS
#error "Kernel symbol CONFIG_HIGH_RES_TIMERS is required."
#endif

// TracePoint support for realtime-debugging
#ifdef _DBG_TRACE_POINTS_
void PUBLIC TgtDbgSignalTracePoint(BYTE bTracePointNumber_p);
void PUBLIC TgtDbgPostTraceValue(DWORD dwTraceValue_p);
#define TGT_DBG_SIGNAL_TRACE_POINT(p)   TgtDbgSignalTracePoint(p)
#define TGT_DBG_POST_TRACE_VALUE(v)     TgtDbgPostTraceValue(v)
#else
#define TGT_DBG_SIGNAL_TRACE_POINT(p)
#define TGT_DBG_POST_TRACE_VALUE(v)
#endif
#define HRT_DBG_POST_TRACE_VALUE(Event_p, uiNodeId_p, wErrorCode_p) \
    TGT_DBG_POST_TRACE_VALUE((0xE << 28) | (Event_p << 24) \
                             | (uiNodeId_p << 16) | wErrorCode_p)

#define TIMERHDL_MASK         0x0FFFFFFF
#define TIMERHDL_SHIFT        28
#define HDL_TO_IDX(Hdl)       ((Hdl >> TIMERHDL_SHIFT) - 1)
#define HDL_INIT(Idx)         ((Idx + 1) << TIMERHDL_SHIFT)
#define HDL_INC(Hdl)          (((Hdl + 1) & TIMERHDL_MASK) \
                               | (Hdl & ~TIMERHDL_MASK))

//---------------------------------------------------------------------------
// modul global types
//---------------------------------------------------------------------------

typedef struct {
	tEplTimerEventArg m_EventArg;
	tEplTimerkCallback m_pfnCallback;
	struct hrtimer m_Timer;
	BOOL m_fContinuously;
	unsigned long long m_ullPeriod;

} tEplTimerHighReskTimerInfo;

typedef struct {
	tEplTimerHighReskTimerInfo m_aTimerInfo[TIMER_COUNT];

} tEplTimerHighReskInstance;

//---------------------------------------------------------------------------
// local vars
//---------------------------------------------------------------------------

static tEplTimerHighReskInstance EplTimerHighReskInstance_l;

//---------------------------------------------------------------------------
// local function prototypes
//---------------------------------------------------------------------------

enum hrtimer_restart EplTimerHighReskCallback(struct hrtimer *pTimer_p);

//=========================================================================//
//                                                                         //
//          P U B L I C   F U N C T I O N S                                //
//                                                                         //
//=========================================================================//

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskInit()
//
// Description: initializes the high resolution timer module.
//
// Parameters:  void
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskInit(void)
{
	tEplKernel Ret;

	Ret = EplTimerHighReskAddInstance();

	return Ret;

}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskAddInstance()
//
// Description: initializes the high resolution timer module.
//
// Parameters:  void
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskAddInstance(void)
{
	tEplKernel Ret;
	unsigned int uiIndex;

	Ret = kEplSuccessful;

	EPL_MEMSET(&EplTimerHighReskInstance_l, 0,
		   sizeof(EplTimerHighReskInstance_l));

#ifndef CONFIG_HIGH_RES_TIMERS
	printk
	    ("EplTimerHighResk: Kernel symbol CONFIG_HIGH_RES_TIMERS is required.\n");
	Ret = kEplNoResource;
	return Ret;
#endif

	/*
	 * Initialize hrtimer structures for all usable timers.
	 */
	for (uiIndex = 0; uiIndex < TIMER_COUNT; uiIndex++) {
		tEplTimerHighReskTimerInfo *pTimerInfo;
		struct hrtimer *pTimer;

		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
		pTimer = &pTimerInfo->m_Timer;
		hrtimer_init(pTimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);

		pTimer->function = EplTimerHighReskCallback;
	}

	return Ret;
}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskDelInstance()
//
// Description: shuts down the high resolution timer module.
//
// Parameters:  void
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskDelInstance(void)
{
	tEplTimerHighReskTimerInfo *pTimerInfo;
	tEplKernel Ret;
	unsigned int uiIndex;

	Ret = kEplSuccessful;

	for (uiIndex = 0; uiIndex < TIMER_COUNT; uiIndex++) {
		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[0];
		pTimerInfo->m_pfnCallback = NULL;
		pTimerInfo->m_EventArg.m_TimerHdl = 0;
		/*
		 * In this case we can not just try to cancel the timer.
		 * We actually have to wait until its callback function
		 * has returned.
		 */
		hrtimer_cancel(&pTimerInfo->m_Timer);
	}

	return Ret;

}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskModifyTimerNs()
//
// Description: modifies the timeout of the timer with the specified handle.
//              If the handle the pointer points to is zero, the timer must
//              be created first.
//              If it is not possible to stop the old timer,
//              this function always assures that the old timer does not
//              trigger the callback function with the same handle as the new
//              timer. That means the callback function must check the passed
//              handle with the one returned by this function. If these are
//              unequal, the call can be discarded.
//
// Parameters:  pTimerHdl_p     = pointer to timer handle
//              ullTimeNs_p     = relative timeout in [ns]
//              pfnCallback_p   = callback function, which is called mutual
//                                exclusive with the Edrv callback functions
//                                (Rx and Tx).
//              ulArgument_p    = user-specific argument
//              fContinuously_p = if TRUE, callback function will be called
//                                continuously;
//                                otherwise, it is a oneshot timer.
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskModifyTimerNs(tEplTimerHdl * pTimerHdl_p,
						unsigned long long ullTimeNs_p,
						tEplTimerkCallback
						pfnCallback_p,
						unsigned long ulArgument_p,
						BOOL fContinuously_p)
{
	tEplKernel Ret;
	unsigned int uiIndex;
	tEplTimerHighReskTimerInfo *pTimerInfo;
	ktime_t RelTime;

	Ret = kEplSuccessful;

	// check pointer to handle
	if (pTimerHdl_p == NULL) {
		Ret = kEplTimerInvalidHandle;
		goto Exit;
	}

	if (*pTimerHdl_p == 0) {	// no timer created yet

		// search free timer info structure
		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[0];
		for (uiIndex = 0; uiIndex < TIMER_COUNT;
		     uiIndex++, pTimerInfo++) {
			if (pTimerInfo->m_EventArg.m_TimerHdl == 0) {	// free structure found
				break;
			}
		}
		if (uiIndex >= TIMER_COUNT) {	// no free structure found
			Ret = kEplTimerNoTimerCreated;
			goto Exit;
		}

		pTimerInfo->m_EventArg.m_TimerHdl = HDL_INIT(uiIndex);
	} else {
		uiIndex = HDL_TO_IDX(*pTimerHdl_p);
		if (uiIndex >= TIMER_COUNT) {	// invalid handle
			Ret = kEplTimerInvalidHandle;
			goto Exit;
		}

		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
	}

	/*
	 * increment timer handle
	 * (if timer expires right after this statement, the user
	 * would detect an unknown timer handle and discard it)
	 */
	pTimerInfo->m_EventArg.m_TimerHdl =
	    HDL_INC(pTimerInfo->m_EventArg.m_TimerHdl);
	*pTimerHdl_p = pTimerInfo->m_EventArg.m_TimerHdl;

	// reject too small time values
	if ((fContinuously_p && (ullTimeNs_p < TIMER_MIN_VAL_CYCLE))
	    || (!fContinuously_p && (ullTimeNs_p < TIMER_MIN_VAL_SINGLE))) {
		Ret = kEplTimerNoTimerCreated;
		goto Exit;
	}

	pTimerInfo->m_EventArg.m_ulArg = ulArgument_p;
	pTimerInfo->m_pfnCallback = pfnCallback_p;
	pTimerInfo->m_fContinuously = fContinuously_p;
	pTimerInfo->m_ullPeriod = ullTimeNs_p;

	/*
	 * HRTIMER_MODE_REL does not influence general handling of this timer.
	 * It only sets relative mode for this start operation.
	 * -> Expire time is calculated by: Now + RelTime
	 * hrtimer_start also skips pending timer events.
	 * The state HRTIMER_STATE_CALLBACK is ignored.
	 * We have to cope with that in our callback function.
	 */
	RelTime = ktime_add_ns(ktime_set(0, 0), ullTimeNs_p);
	hrtimer_start(&pTimerInfo->m_Timer, RelTime, HRTIMER_MODE_REL);

      Exit:
	return Ret;

}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskDeleteTimer()
//
// Description: deletes the timer with the specified handle. Afterward the
//              handle is set to zero.
//
// Parameters:  pTimerHdl_p     = pointer to timer handle
//
// Return:      tEplKernel      = error code
//
// State:       not tested
//
//---------------------------------------------------------------------------

tEplKernel PUBLIC EplTimerHighReskDeleteTimer(tEplTimerHdl * pTimerHdl_p)
{
	tEplKernel Ret = kEplSuccessful;
	unsigned int uiIndex;
	tEplTimerHighReskTimerInfo *pTimerInfo;

	// check pointer to handle
	if (pTimerHdl_p == NULL) {
		Ret = kEplTimerInvalidHandle;
		goto Exit;
	}

	if (*pTimerHdl_p == 0) {	// no timer created yet
		goto Exit;
	} else {
		uiIndex = HDL_TO_IDX(*pTimerHdl_p);
		if (uiIndex >= TIMER_COUNT) {	// invalid handle
			Ret = kEplTimerInvalidHandle;
			goto Exit;
		}
		pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
		if (pTimerInfo->m_EventArg.m_TimerHdl != *pTimerHdl_p) {	// invalid handle
			goto Exit;
		}
	}

	*pTimerHdl_p = 0;
	pTimerInfo->m_EventArg.m_TimerHdl = 0;
	pTimerInfo->m_pfnCallback = NULL;

	/*
	 * Three return cases of hrtimer_try_to_cancel have to be tracked:
	 *  1 - timer has been removed
	 *  0 - timer was not active
	 *      We need not do anything. hrtimer timers just consist of
	 *      a hrtimer struct, which we might enqueue in the hrtimers
	 *      event list by calling hrtimer_start().
	 *      If a timer is not enqueued, it is not present in hrtimers.
	 * -1 - callback function is running
	 *      In this case we have to ensure that the timer is not
	 *      continuously restarted. This has been done by clearing
	 *      its handle.
	 */
	hrtimer_try_to_cancel(&pTimerInfo->m_Timer);

      Exit:
	return Ret;

}

//---------------------------------------------------------------------------
//
// Function:    EplTimerHighReskCallback()
//
// Description: Callback function commonly used for all timers.
//
// Parameters:  pTimer_p = pointer to hrtimer
//
// Return:
//
// State:       not tested
//
//---------------------------------------------------------------------------

enum hrtimer_restart EplTimerHighReskCallback(struct hrtimer *pTimer_p)
{
	unsigned int uiIndex;
	tEplTimerHighReskTimerInfo *pTimerInfo;
	tEplTimerHdl OrgTimerHdl;
	enum hrtimer_restart Ret;

	BENCHMARK_MOD_24_SET(4);

	Ret = HRTIMER_NORESTART;
	pTimerInfo =
	    container_of(pTimer_p, tEplTimerHighReskTimerInfo, m_Timer);
	uiIndex = HDL_TO_IDX(pTimerInfo->m_EventArg.m_TimerHdl);
	if (uiIndex >= TIMER_COUNT) {	// invalid handle
		goto Exit;
	}

	/*
	 * We store the timer handle before calling the callback function
	 * as the timer can be modified inside it.
	 */
	OrgTimerHdl = pTimerInfo->m_EventArg.m_TimerHdl;

	if (pTimerInfo->m_pfnCallback != NULL) {
		pTimerInfo->m_pfnCallback(&pTimerInfo->m_EventArg);
	}

	if (pTimerInfo->m_fContinuously) {
		ktime_t Interval;
#ifdef PROVE_OVERRUN
		ktime_t Now;
		unsigned long Overruns;
#endif

		if (OrgTimerHdl != pTimerInfo->m_EventArg.m_TimerHdl) {
			/* modified timer has already been restarted */
			goto Exit;
		}
#ifdef PROVE_OVERRUN
		Now = ktime_get();
		Interval =
		    ktime_add_ns(ktime_set(0, 0), pTimerInfo->m_ullPeriod);
		Overruns = hrtimer_forward(pTimer_p, Now, Interval);
		if (Overruns > 1) {
			printk
			    ("EplTimerHighResk: Continuous timer (handle 0x%lX) had to skip %lu interval(s)!\n",
			     pTimerInfo->m_EventArg.m_TimerHdl, Overruns - 1);
		}
#else
		pTimer_p->expires = ktime_add_ns(pTimer_p->expires,
						 pTimerInfo->m_ullPeriod);
#endif

		Ret = HRTIMER_RESTART;
	}

      Exit:
	BENCHMARK_MOD_24_RESET(4);
	return Ret;
}
Commit	Line	Data
9d7164cf DK	1	/****************************************************************************
	2
	3	(c) SYSTEC electronic GmbH, D-07973 Greiz, August-Bebel-Str. 29
	4	www.systec-electronic.com
	5
	6	Project: openPOWERLINK
	7
	8	Description: target specific implementation of
	9	high resolution timer module for X86 under Linux
	10	The Linux kernel has to be compiled with high resolution
	11	timers enabled. This is done by configuring the kernel
	12	with CONFIG_HIGH_RES_TIMERS enabled.
	13
	14	License:
	15
	16	Redistribution and use in source and binary forms, with or without
	17	modification, are permitted provided that the following conditions
	18	are met:
	19
	20	1. Redistributions of source code must retain the above copyright
	21	notice, this list of conditions and the following disclaimer.
	22
	23	2. Redistributions in binary form must reproduce the above copyright
	24	notice, this list of conditions and the following disclaimer in the
	25	documentation and/or other materials provided with the distribution.
	26
	27	3. Neither the name of SYSTEC electronic GmbH nor the names of its
	28	contributors may be used to endorse or promote products derived
	29	from this software without prior written permission. For written
	30	permission, please contact info@systec-electronic.com.
	31
	32	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	33	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	34	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	35	FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	36	COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	37	INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
	38	BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	39	LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	40	CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	41	LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
	42	ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	43	POSSIBILITY OF SUCH DAMAGE.
	44
	45	Severability Clause:
	46
	47	If a provision of this License is or becomes illegal, invalid or
	48	unenforceable in any jurisdiction, that shall not affect:
	49	1. the validity or enforceability in that jurisdiction of any other
	50	provision of this License; or
	51	2. the validity or enforceability in other jurisdictions of that or
	52	any other provision of this License.
	53
	54	-------------------------------------------------------------------------
	55
	56	$RCSfile: TimerHighReskX86.c,v $
	57
	58	$Author: D.Krueger $
	59
	60	$Revision: 1.4 $ $Date: 2008/04/17 21:38:01 $
	61
	62	$State: Exp $
	63
	64	Build Environment:
65	GNU
66
67	-------------------------------------------------------------------------
68
69	Revision History:
70
71	****************************************************************************/
72
73	#include "EplInc.h"
74	#include "kernel/EplTimerHighResk.h"
75	#include "Benchmark.h"
76
77	//#include <linux/config.h>
78	#include <linux/module.h>
79	#include <linux/kernel.h>
80	#include <linux/hrtimer.h>
81
82	/***************************************************************************/
83	/* */
84	/* */
85	/* G L O B A L D E F I N I T I O N S */
86	/* */
87	/* */
88	/***************************************************************************/
89
90	//---------------------------------------------------------------------------
91	// const defines
92	//---------------------------------------------------------------------------
93
833dfbe7 GKH	94	#define TIMER_COUNT 2 /* max 15 timers selectable */
	95	#define TIMER_MIN_VAL_SINGLE 5000 /* min 5us */
	96	#define TIMER_MIN_VAL_CYCLE 100000 /* min 100us */
9d7164cf DK	97
	98	#define PROVE_OVERRUN
	99
9d7164cf	100	#ifndef CONFIG_HIGH_RES_TIMERS
833dfbe7	101	#error "Kernel symbol CONFIG_HIGH_RES_TIMERS is required."
9d7164cf DK	102	#endif
9d7164cf DK	103
9d7164cf DK	104	// TracePoint support for realtime-debugging
9d7164cf DK	105	#ifdef _DBG_TRACE_POINTS_
833dfbe7 GKH	106	void PUBLIC TgtDbgSignalTracePoint(BYTE bTracePointNumber_p);
	107	void PUBLIC TgtDbgPostTraceValue(DWORD dwTraceValue_p);
	108	#define TGT_DBG_SIGNAL_TRACE_POINT(p) TgtDbgSignalTracePoint(p)
	109	#define TGT_DBG_POST_TRACE_VALUE(v) TgtDbgPostTraceValue(v)
9d7164cf	110	#else
833dfbe7 GKH	111	#define TGT_DBG_SIGNAL_TRACE_POINT(p)
833dfbe7 GKH	112	#define TGT_DBG_POST_TRACE_VALUE(v)
9d7164cf DK	113	#endif
	114	#define HRT_DBG_POST_TRACE_VALUE(Event_p, uiNodeId_p, wErrorCode_p) \
	115	TGT_DBG_POST_TRACE_VALUE((0xE << 28) \| (Event_p << 24) \
	116	\| (uiNodeId_p << 16) \| wErrorCode_p)
	117
	118	#define TIMERHDL_MASK 0x0FFFFFFF
	119	#define TIMERHDL_SHIFT 28
	120	#define HDL_TO_IDX(Hdl) ((Hdl >> TIMERHDL_SHIFT) - 1)
	121	#define HDL_INIT(Idx) ((Idx + 1) << TIMERHDL_SHIFT)
	122	#define HDL_INC(Hdl) (((Hdl + 1) & TIMERHDL_MASK) \
	123	\| (Hdl & ~TIMERHDL_MASK))
	124
	125	//---------------------------------------------------------------------------
	126	// modul global types
	127	//---------------------------------------------------------------------------
	128
833dfbe7 GKH	129	typedef struct {
	130	tEplTimerEventArg m_EventArg;
	131	tEplTimerkCallback m_pfnCallback;
	132	struct hrtimer m_Timer;
	133	BOOL m_fContinuously;
	134	unsigned long long m_ullPeriod;
9d7164cf DK	135
	136	} tEplTimerHighReskTimerInfo;
	137
833dfbe7 GKH	138	typedef struct {
833dfbe7 GKH	139	tEplTimerHighReskTimerInfo m_aTimerInfo[TIMER_COUNT];
9d7164cf DK	140
	141	} tEplTimerHighReskInstance;
	142
	143	//---------------------------------------------------------------------------
	144	// local vars
	145	//---------------------------------------------------------------------------
	146
833dfbe7	147	static tEplTimerHighReskInstance EplTimerHighReskInstance_l;
9d7164cf DK	148
	149	//---------------------------------------------------------------------------
	150	// local function prototypes
	151	//---------------------------------------------------------------------------
	152
833dfbe7	153	enum hrtimer_restart EplTimerHighReskCallback(struct hrtimer *pTimer_p);
9d7164cf DK	154
	155	//=========================================================================//
	156	// //
	157	// P U B L I C F U N C T I O N S //
	158	// //
	159	//=========================================================================//
	160
9d7164cf DK	161	//---------------------------------------------------------------------------
	162	//
	163	// Function: EplTimerHighReskInit()
	164	//
	165	// Description: initializes the high resolution timer module.
	166	//
	167	// Parameters: void
	168	//
	169	// Return: tEplKernel = error code
	170	//
	171	// State: not tested
	172	//
	173	//---------------------------------------------------------------------------
	174
	175	tEplKernel PUBLIC EplTimerHighReskInit(void)
	176	{
833dfbe7	177	tEplKernel Ret;
9d7164cf	178
833dfbe7	179	Ret = EplTimerHighReskAddInstance();
9d7164cf	180
833dfbe7	181	return Ret;
9d7164cf DK	182
	183	}
	184
9d7164cf DK	185	//---------------------------------------------------------------------------
	186	//
	187	// Function: EplTimerHighReskAddInstance()
	188	//
	189	// Description: initializes the high resolution timer module.
	190	//
	191	// Parameters: void
	192	//
	193	// Return: tEplKernel = error code
	194	//
	195	// State: not tested
	196	//
	197	//---------------------------------------------------------------------------
	198
	199	tEplKernel PUBLIC EplTimerHighReskAddInstance(void)
	200	{
833dfbe7 GKH	201	tEplKernel Ret;
833dfbe7 GKH	202	unsigned int uiIndex;
9d7164cf	203
833dfbe7	204	Ret = kEplSuccessful;
9d7164cf	205
833dfbe7 GKH	206	EPL_MEMSET(&EplTimerHighReskInstance_l, 0,
833dfbe7 GKH	207	sizeof(EplTimerHighReskInstance_l));
9d7164cf DK	208
9d7164cf DK	209	#ifndef CONFIG_HIGH_RES_TIMERS
833dfbe7 GKH	210	printk
	211	("EplTimerHighResk: Kernel symbol CONFIG_HIGH_RES_TIMERS is required.\n");
	212	Ret = kEplNoResource;
	213	return Ret;
9d7164cf DK	214	#endif
9d7164cf DK	215
833dfbe7 GKH	216	/*
	217	* Initialize hrtimer structures for all usable timers.
	218	*/
	219	for (uiIndex = 0; uiIndex < TIMER_COUNT; uiIndex++) {
	220	tEplTimerHighReskTimerInfo *pTimerInfo;
	221	struct hrtimer *pTimer;
	222
	223	pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
	224	pTimer = &pTimerInfo->m_Timer;
	225	hrtimer_init(pTimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
	226
	227	pTimer->function = EplTimerHighReskCallback;
833dfbe7 GKH	228	}
	229
	230	return Ret;
	231	}
9d7164cf DK	232
	233	//---------------------------------------------------------------------------
	234	//
	235	// Function: EplTimerHighReskDelInstance()
	236	//
	237	// Description: shuts down the high resolution timer module.
	238	//
	239	// Parameters: void
	240	//
	241	// Return: tEplKernel = error code
	242	//
	243	// State: not tested
	244	//
	245	//---------------------------------------------------------------------------
	246
	247	tEplKernel PUBLIC EplTimerHighReskDelInstance(void)
	248	{
833dfbe7 GKH	249	tEplTimerHighReskTimerInfo *pTimerInfo;
	250	tEplKernel Ret;
	251	unsigned int uiIndex;
	252
	253	Ret = kEplSuccessful;
	254
	255	for (uiIndex = 0; uiIndex < TIMER_COUNT; uiIndex++) {
	256	pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[0];
	257	pTimerInfo->m_pfnCallback = NULL;
	258	pTimerInfo->m_EventArg.m_TimerHdl = 0;
	259	/*
	260	* In this case we can not just try to cancel the timer.
	261	* We actually have to wait until its callback function
	262	* has returned.
	263	*/
	264	hrtimer_cancel(&pTimerInfo->m_Timer);
	265	}
	266
	267	return Ret;
9d7164cf DK	268
	269	}
	270
9d7164cf DK	271	//---------------------------------------------------------------------------
	272	//
	273	// Function: EplTimerHighReskModifyTimerNs()
	274	//
	275	// Description: modifies the timeout of the timer with the specified handle.
	276	// If the handle the pointer points to is zero, the timer must
	277	// be created first.
	278	// If it is not possible to stop the old timer,
	279	// this function always assures that the old timer does not
	280	// trigger the callback function with the same handle as the new
	281	// timer. That means the callback function must check the passed
	282	// handle with the one returned by this function. If these are
	283	// unequal, the call can be discarded.
	284	//
	285	// Parameters: pTimerHdl_p = pointer to timer handle
	286	// ullTimeNs_p = relative timeout in [ns]
	287	// pfnCallback_p = callback function, which is called mutual
	288	// exclusive with the Edrv callback functions
	289	// (Rx and Tx).
	290	// ulArgument_p = user-specific argument
	291	// fContinuously_p = if TRUE, callback function will be called
	292	// continuously;
	293	// otherwise, it is a oneshot timer.
	294	//
	295	// Return: tEplKernel = error code
	296	//
	297	// State: not tested
	298	//
	299	//---------------------------------------------------------------------------
	300
833dfbe7 GKH	301	tEplKernel PUBLIC EplTimerHighReskModifyTimerNs(tEplTimerHdl * pTimerHdl_p,
	302	unsigned long long ullTimeNs_p,
	303	tEplTimerkCallback
	304	pfnCallback_p,
	305	unsigned long ulArgument_p,
	306	BOOL fContinuously_p)
9d7164cf	307	{
833dfbe7 GKH	308	tEplKernel Ret;
	309	unsigned int uiIndex;
	310	tEplTimerHighReskTimerInfo *pTimerInfo;
	311	ktime_t RelTime;
	312
	313	Ret = kEplSuccessful;
	314
	315	// check pointer to handle
	316	if (pTimerHdl_p == NULL) {
	317	Ret = kEplTimerInvalidHandle;
	318	goto Exit;
	319	}
	320
	321	if (*pTimerHdl_p == 0) { // no timer created yet
	322
	323	// search free timer info structure
	324	pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[0];
	325	for (uiIndex = 0; uiIndex < TIMER_COUNT;
	326	uiIndex++, pTimerInfo++) {
	327	if (pTimerInfo->m_EventArg.m_TimerHdl == 0) { // free structure found
	328	break;
	329	}
	330	}
	331	if (uiIndex >= TIMER_COUNT) { // no free structure found
	332	Ret = kEplTimerNoTimerCreated;
	333	goto Exit;
	334	}
	335
	336	pTimerInfo->m_EventArg.m_TimerHdl = HDL_INIT(uiIndex);
	337	} else {
	338	uiIndex = HDL_TO_IDX(*pTimerHdl_p);
	339	if (uiIndex >= TIMER_COUNT) { // invalid handle
	340	Ret = kEplTimerInvalidHandle;
	341	goto Exit;
	342	}
	343
	344	pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
	345	}
	346
	347	/*
	348	* increment timer handle
	349	* (if timer expires right after this statement, the user
	350	* would detect an unknown timer handle and discard it)
	351	*/
	352	pTimerInfo->m_EventArg.m_TimerHdl =
	353	HDL_INC(pTimerInfo->m_EventArg.m_TimerHdl);
	354	*pTimerHdl_p = pTimerInfo->m_EventArg.m_TimerHdl;
	355
	356	// reject too small time values
	357	if ((fContinuously_p && (ullTimeNs_p < TIMER_MIN_VAL_CYCLE))
	358	\|\| (!fContinuously_p && (ullTimeNs_p < TIMER_MIN_VAL_SINGLE))) {
	359	Ret = kEplTimerNoTimerCreated;
	360	goto Exit;
	361	}
	362
	363	pTimerInfo->m_EventArg.m_ulArg = ulArgument_p;
	364	pTimerInfo->m_pfnCallback = pfnCallback_p;
	365	pTimerInfo->m_fContinuously = fContinuously_p;
	366	pTimerInfo->m_ullPeriod = ullTimeNs_p;
	367
	368	/*
	369	* HRTIMER_MODE_REL does not influence general handling of this timer.
	370	* It only sets relative mode for this start operation.
	371	* -> Expire time is calculated by: Now + RelTime
372	* hrtimer_start also skips pending timer events.
373	* The state HRTIMER_STATE_CALLBACK is ignored.
374	* We have to cope with that in our callback function.
375	*/
376	RelTime = ktime_add_ns(ktime_set(0, 0), ullTimeNs_p);
377	hrtimer_start(&pTimerInfo->m_Timer, RelTime, HRTIMER_MODE_REL);
378
379	Exit:
380	return Ret;
9d7164cf DK	381
	382	}
	383
9d7164cf DK	384	//---------------------------------------------------------------------------
	385	//
	386	// Function: EplTimerHighReskDeleteTimer()
	387	//
	388	// Description: deletes the timer with the specified handle. Afterward the
	389	// handle is set to zero.
	390	//
	391	// Parameters: pTimerHdl_p = pointer to timer handle
	392	//
	393	// Return: tEplKernel = error code
	394	//
	395	// State: not tested
	396	//
	397	//---------------------------------------------------------------------------
	398
833dfbe7	399	tEplKernel PUBLIC EplTimerHighReskDeleteTimer(tEplTimerHdl * pTimerHdl_p)
9d7164cf	400	{
833dfbe7 GKH	401	tEplKernel Ret = kEplSuccessful;
	402	unsigned int uiIndex;
	403	tEplTimerHighReskTimerInfo *pTimerInfo;
	404
	405	// check pointer to handle
	406	if (pTimerHdl_p == NULL) {
	407	Ret = kEplTimerInvalidHandle;
	408	goto Exit;
	409	}
	410
	411	if (*pTimerHdl_p == 0) { // no timer created yet
	412	goto Exit;
	413	} else {
	414	uiIndex = HDL_TO_IDX(*pTimerHdl_p);
	415	if (uiIndex >= TIMER_COUNT) { // invalid handle
	416	Ret = kEplTimerInvalidHandle;
	417	goto Exit;
	418	}
	419	pTimerInfo = &EplTimerHighReskInstance_l.m_aTimerInfo[uiIndex];
	420	if (pTimerInfo->m_EventArg.m_TimerHdl != *pTimerHdl_p) { // invalid handle
	421	goto Exit;
	422	}
	423	}
	424
	425	*pTimerHdl_p = 0;
	426	pTimerInfo->m_EventArg.m_TimerHdl = 0;
	427	pTimerInfo->m_pfnCallback = NULL;
	428
	429	/*
	430	* Three return cases of hrtimer_try_to_cancel have to be tracked:
	431	* 1 - timer has been removed
	432	* 0 - timer was not active
	433	* We need not do anything. hrtimer timers just consist of
	434	* a hrtimer struct, which we might enqueue in the hrtimers
	435	* event list by calling hrtimer_start().
	436	* If a timer is not enqueued, it is not present in hrtimers.
	437	* -1 - callback function is running
	438	* In this case we have to ensure that the timer is not
	439	* continuously restarted. This has been done by clearing
	440	* its handle.
	441	*/
	442	hrtimer_try_to_cancel(&pTimerInfo->m_Timer);
	443
	444	Exit:
	445	return Ret;
9d7164cf DK	446
	447	}
	448
9d7164cf DK	449	//---------------------------------------------------------------------------
	450	//
	451	// Function: EplTimerHighReskCallback()
	452	//
	453	// Description: Callback function commonly used for all timers.
	454	//
	455	// Parameters: pTimer_p = pointer to hrtimer
	456	//
	457	// Return:
	458	//
	459	// State: not tested
	460	//
	461	//---------------------------------------------------------------------------
	462
833dfbe7	463	enum hrtimer_restart EplTimerHighReskCallback(struct hrtimer *pTimer_p)
9d7164cf	464	{
833dfbe7 GKH	465	unsigned int uiIndex;
	466	tEplTimerHighReskTimerInfo *pTimerInfo;
	467	tEplTimerHdl OrgTimerHdl;
	468	enum hrtimer_restart Ret;
	469
	470	BENCHMARK_MOD_24_SET(4);
	471
	472	Ret = HRTIMER_NORESTART;
	473	pTimerInfo =
	474	container_of(pTimer_p, tEplTimerHighReskTimerInfo, m_Timer);
	475	uiIndex = HDL_TO_IDX(pTimerInfo->m_EventArg.m_TimerHdl);
	476	if (uiIndex >= TIMER_COUNT) { // invalid handle
	477	goto Exit;
	478	}
	479
	480	/*
	481	* We store the timer handle before calling the callback function
	482	* as the timer can be modified inside it.
	483	*/
	484	OrgTimerHdl = pTimerInfo->m_EventArg.m_TimerHdl;
	485
	486	if (pTimerInfo->m_pfnCallback != NULL) {
	487	pTimerInfo->m_pfnCallback(&pTimerInfo->m_EventArg);
	488	}
	489
	490	if (pTimerInfo->m_fContinuously) {
	491	ktime_t Interval;
9d7164cf	492	#ifdef PROVE_OVERRUN
833dfbe7 GKH	493	ktime_t Now;
833dfbe7 GKH	494	unsigned long Overruns;
9d7164cf DK	495	#endif
9d7164cf DK	496
833dfbe7 GKH	497	if (OrgTimerHdl != pTimerInfo->m_EventArg.m_TimerHdl) {
	498	/* modified timer has already been restarted */
	499	goto Exit;
	500	}
9d7164cf	501	#ifdef PROVE_OVERRUN
833dfbe7 GKH	502	Now = ktime_get();
	503	Interval =
	504	ktime_add_ns(ktime_set(0, 0), pTimerInfo->m_ullPeriod);
	505	Overruns = hrtimer_forward(pTimer_p, Now, Interval);
	506	if (Overruns > 1) {
	507	printk
	508	("EplTimerHighResk: Continuous timer (handle 0x%lX) had to skip %lu interval(s)!\n",
	509	pTimerInfo->m_EventArg.m_TimerHdl, Overruns - 1);
	510	}
9d7164cf	511	#else
833dfbe7 GKH	512	pTimer_p->expires = ktime_add_ns(pTimer_p->expires,
833dfbe7 GKH	513	pTimerInfo->m_ullPeriod);
9d7164cf DK	514	#endif
9d7164cf DK	515
833dfbe7 GKH	516	Ret = HRTIMER_RESTART;
833dfbe7 GKH	517	}
9d7164cf	518
833dfbe7 GKH	519	Exit:
	520	BENCHMARK_MOD_24_RESET(4);
	521	return Ret;
9d7164cf	522	}