[FFADO-svn] r1341 - branches/libffado-2.0/src/libieee1394

[<tr...@ff...>]

Author: ppalmers
Date: 2008-09-24 05:34:53 -0700 (Wed, 24 Sep 2008)
New Revision: 1341

Modified:
   branches/libffado-2.0/src/libieee1394/CycleTimerHelper.cpp
   branches/libffado-2.0/src/libieee1394/CycleTimerHelper.h
   branches/libffado-2.0/src/libieee1394/ieee1394service.cpp
   branches/libffado-2.0/src/libieee1394/ieee1394service.h
Log:
Add reverse mapping support to obtain system time based upon the ctr value



Modified: branches/libffado-2.0/src/libieee1394/CycleTimerHelper.cpp
===================================================================
--- branches/libffado-2.0/src/libieee1394/CycleTimerHelper.cpp	2008-09-23 21:51:42 UTC (rev 1340)
+++ branches/libffado-2.0/src/libieee1394/CycleTimerHelper.cpp	2008-09-24 12:34:53 UTC (rev 1341)
@@ -653,6 +653,38 @@
     return result;
 }
 
+uint64_t
+CycleTimerHelper::getSystemTimeForCycleTimerTicks(uint32_t ticks)
+{
+    uint64_t retval;
+    struct compute_vars *my_vars;
+
+    // get pointer and copy the contents
+    // no locking should be needed since we have more than one
+    // of these vars available, and our use will always be finished before
+    // m_current_shadow_idx changes since this thread's priority should
+    // be higher than the one of the writer thread. Even if not, we only have to ensure
+    // that the used dataset is consistent. We can use an older dataset if it's consistent
+    // since it will also provide a fairly decent extrapolation.
+    my_vars = m_shadow_vars + m_current_shadow_idx;
+
+    // the number of ticks the request is ahead of the current CTR position
+    int64_t ticks_diff = diffTicks(ticks, my_vars->ticks);
+    // to how much time does this correspond?
+    double x_step_in_usec = ((double)ticks_diff) / my_vars->rate;
+    int64_t x_step_in_usec_int = (int64_t)x_step_in_usec;
+    retval = my_vars->usecs + x_step_in_usec_int;
+
+    return retval;
+}
+
+uint64_t
+CycleTimerHelper::getSystemTimeForCycleTimer(uint32_t ctr)
+{
+    uint32_t ticks = CYCLE_TIMER_TO_TICKS(ctr);
+    return getSystemTimeForCycleTimerTicks(ticks);
+}
+
 #else
 
 float
@@ -684,8 +716,18 @@
 uint32_t
 CycleTimerHelper::getCycleTimerTicks(uint64_t now)
 {
-    debugWarning("not implemented!\n");
-    return getCycleTimerTicks();
+    debugWarning("untested code\n");
+    #warning Untested code
+    uint32_t cycle_timer;
+    uint64_t local_time;
+    readCycleTimerWithRetry(&cycle_timer, &local_time, 10);
+    int64_t ticks = CYCLE_TIMER_TO_TICKS(cycle_timer);
+
+    int delta_t = now - local_time; // how far ahead is the request?
+    ticks += delta_t * getRate(); // add ticks
+    if (ticks >= TICKS_PER_SECOND * 128) ticks -= TICKS_PER_SECOND * 128;
+    else if (ticks < 0) ticks += TICKS_PER_SECOND * 128;
+    return ticks;
 }
 
 uint32_t
@@ -700,10 +742,23 @@
 uint32_t
 CycleTimerHelper::getCycleTimer(uint64_t now)
 {
+    return TICKS_TO_CYCLE_TIMER(getCycleTimerTicks(now));
+}
+
+uint64_t
+CycleTimerHelper::getSystemTimeForCycleTimerTicks(uint32_t ticks)
+{
     debugWarning("not implemented!\n");
-    return getCycleTimer();
+    return 0;
 }
 
+uint64_t
+CycleTimerHelper::getSystemTimeForCycleTimer(uint32_t ctr)
+{
+    uint32_t ticks = CYCLE_TIMER_TO_TICKS(ctr);
+    return getSystemTimeForCycleTimerTicks(ticks);
+}
+
 #endif
 
 bool

Modified: branches/libffado-2.0/src/libieee1394/CycleTimerHelper.h
===================================================================
--- branches/libffado-2.0/src/libieee1394/CycleTimerHelper.h	2008-09-23 21:51:42 UTC (rev 1340)
+++ branches/libffado-2.0/src/libieee1394/CycleTimerHelper.h	2008-09-24 12:34:53 UTC (rev 1341)
@@ -97,6 +97,18 @@
      */
     uint32_t getCycleTimer(uint64_t now);
 
+    /**
+     * @brief get the system time for a specific cycle timer value (in ticks)
+     * @note thread safe
+     */
+    uint64_t getSystemTimeForCycleTimerTicks(uint32_t ticks);
+
+    /**
+     * @brief get the system time for a specific cycle timer value (in CTR format)
+     * @note thread safe
+     */
+    uint64_t getSystemTimeForCycleTimer(uint32_t ctr);
+
     float getRate();
     float getNominalRate();
 

Modified: branches/libffado-2.0/src/libieee1394/ieee1394service.cpp
===================================================================
--- branches/libffado-2.0/src/libieee1394/ieee1394service.cpp	2008-09-23 21:51:42 UTC (rev 1340)
+++ branches/libffado-2.0/src/libieee1394/ieee1394service.cpp	2008-09-24 12:34:53 UTC (rev 1341)
@@ -384,6 +384,16 @@
     return m_pCTRHelper->getCycleTimer(t);
 }
 
+uint64_t
+Ieee1394Service::getSystemTimeForCycleTimerTicks(uint32_t ticks) {
+    return m_pCTRHelper->getSystemTimeForCycleTimerTicks(ticks);
+}
+
+uint64_t
+Ieee1394Service::getSystemTimeForCycleTimer(uint32_t ctr) {
+    return m_pCTRHelper->getSystemTimeForCycleTimer(ctr);
+}
+
 bool
 Ieee1394Service::readCycleTimerReg(uint32_t *cycle_timer, uint64_t *local_time)
 {

Modified: branches/libffado-2.0/src/libieee1394/ieee1394service.h
===================================================================
--- branches/libffado-2.0/src/libieee1394/ieee1394service.h	2008-09-23 21:51:42 UTC (rev 1340)
+++ branches/libffado-2.0/src/libieee1394/ieee1394service.h	2008-09-24 12:34:53 UTC (rev 1341)
@@ -134,6 +134,18 @@
     uint32_t getCycleTimer(uint64_t t);
 
     /**
+     * @brief get the system time for a specific cycle timer value (in ticks)
+     * @note thread safe
+     */
+    uint64_t getSystemTimeForCycleTimerTicks(uint32_t ticks);
+
+    /**
+     * @brief get the system time for a specific cycle timer value (in CTR format)
+     * @note thread safe
+     */
+    uint64_t getSystemTimeForCycleTimer(uint32_t ctr);
+
+    /**
      * @brief read the cycle timer value from the controller (in CTR format)
      *
      * @note Uses a direct method to read the value from the controller