From 3a2d07062bdde25fee361e167e2b5b2675ab5f11 Mon Sep 17 00:00:00 2001
From: Tom Eichlersmith <eichl008@umn.edu>
Date: Wed, 6 Apr 2022 16:06:35 -0500
Subject: [PATCH] expand elink_relink to more delay values, controlable by user

---
 include/pflib/PolarfireTarget.h | 28 ++++++++++++++++--
 src/pflib/PolarfireTarget.cxx   | 51 ++++++++++++++-------------------
 tool/pftool.cc                  |  7 +++--
 3 files changed, 51 insertions(+), 35 deletions(-)

diff --git a/include/pflib/PolarfireTarget.h b/include/pflib/PolarfireTarget.h
index b446b625..5f862c5a 100644
--- a/include/pflib/PolarfireTarget.h
+++ b/include/pflib/PolarfireTarget.h
@@ -226,11 +226,33 @@ struct PolarfireTarget {
   bool loadBiasSettings(const std::string& file_name);
 
   /** Carries out the standard elink alignment process */
-  void elink_relink(int ilink,int verbosity);
+  void elink_relink(int ilink,int min_delay = 0, int max_delay = 128);
 
-  void delay_loop(int ilink);
+  /**
+   * Go from min_delay up to max_delay stopping only if alignment is achieved
+   *
+   * Using bitslip_loop to test each delay value.
+   *
+   * @param[in] ilink link index to test
+   * @param[in] min_delay minimum value of delay parameter
+   * @param[in] max_delay maximum value of delay parameter
+   */
+  void delay_loop(int ilink, int min_delay, int max_delay);
 
-  bool bitslip_loop(int ilink);
+  /**
+   * check all bitslip values and find the one with
+   * the most correct idle patterns
+   *
+   * each spy returns 60 bytes (or 15 4-byte words),
+   * the idle pattern is 0x9c or 0xac followed by three 0xcc.
+   *
+   * @param[in] ilink link index to loop over
+   * @param[out] best_slip set to best bitslip value
+   * @param[out] best_count set to number of idles that were correct for the best slip
+   * @return true if best slip value is perfect (i.e. link is aligned) 
+   * (all possible words were corect pattern)
+   */
+  bool bitslip_loop(int ilink, int& best_slip, int& best_count);
   
  private:
   int samples_per_event_;
diff --git a/src/pflib/PolarfireTarget.cxx b/src/pflib/PolarfireTarget.cxx
index fb390c14..0db00de6 100644
--- a/src/pflib/PolarfireTarget.cxx
+++ b/src/pflib/PolarfireTarget.cxx
@@ -462,41 +462,41 @@ bool PolarfireTarget::loadBiasSettings(const std::string& file_name) {
   }
 }
 
-void PolarfireTarget::elink_relink(int ilink ,int verbosity) {
+void PolarfireTarget::elink_relink(int ilink, int min_delay, int max_delay) {
   pflib::Elinks& elinks=hcal.elinks();
-
   if (ilink == -1){
     for (int ilink=0; ilink<elinks.nlinks(); ilink++) {
-      delay_loop(ilink);
+      delay_loop(ilink, min_delay, max_delay);
     }
-  } else delay_loop(ilink);
-
+  } else delay_loop(ilink, min_delay, max_delay);
 }
 
-void PolarfireTarget::delay_loop(int ilink){
+void PolarfireTarget::delay_loop(int ilink, int min_delay, int max_delay){
   pflib::Elinks& elinks = hcal.elinks();
-  bool passedBitslipLoop = false;
+  bool aligned = false;
   if (elinks.isActive(ilink)){
-    for (int delay=20; delay<26; delay++){
+    int bitslip, count;
+    for (int delay=min_delay; delay<max_delay; delay++) {
       elinks.setDelay(ilink,delay);
-      passedBitslipLoop = bitslip_loop(ilink);
-       if (passedBitslipLoop) break;
+      aligned = bitslip_loop(ilink,bitslip,count);
+      printf("    Elink %d delay %d bitslip %d  (ok count=%d) %s\n",
+          ilink,delay,bitslip,count,aligned?"alignment achieved":"");
+      if (aligned) break;
     }
-    if (!passedBitslipLoop) printf("Delay scan exceeded 25, you should do an elinks hardreset\n");
+    if (!aligned) printf("Delay scan from %d to %d was unable to align link %d.\n",
+        min_delay,max_delay,ilink);
   } else printf("    Elink %d is not active.\n",ilink);
 }
 
-bool PolarfireTarget::bitslip_loop(int ilink){
+bool PolarfireTarget::bitslip_loop(int ilink, int& best_slip, int& count) {
+  static int total_cycles = 5; // number of spies per bitslip value
   pflib::Elinks& elinks=hcal.elinks();
-    
   elinks.setBitslipAuto(ilink,false);
-    
   int okcount[8];
-    
   for (int slip=0; slip<8; slip++) {
     elinks.setBitslip(ilink,slip);
     okcount[slip]=0;
-    for (int cycles=0; cycles<5; cycles++) {
+    for (int cycles=0; cycles < total_cycles; cycles++) {
       std::vector<uint8_t> spy=elinks.spy(ilink);
       for (size_t i=0; i+4<spy.size(); ) {
         if (spy[i]==0x9c || spy[i]==0xac) {
@@ -506,23 +506,14 @@ bool PolarfireTarget::bitslip_loop(int ilink){
       } 
     }
   }
-  int imax=-1;
+  best_slip = -1;
   for (int slip=0; slip<8; slip++) {
-    if (imax<0 || okcount[slip]>okcount[imax]) imax=slip;
-  }
-  elinks.setBitslip(ilink,imax);
-  printf("    Link %d bitslip %d  (ok count=%d)\n",ilink,imax,okcount[imax]);
-
-  if (okcount[imax] == 75){
-    return true;
+    if (best_slip<0 || okcount[slip]>okcount[best_slip]) best_slip=slip;
   }
-  else return false;
-
+  elinks.setBitslip(ilink,best_slip);
+  count = okcount[best_slip];
+  return (count == 15*total_cycles);
 }
-  
-//}
-
-  
 
 }  // namespace pflib
 
diff --git a/tool/pftool.cc b/tool/pftool.cc
index 7a69622b..ce4e9ee4 100644
--- a/tool/pftool.cc
+++ b/tool/pftool.cc
@@ -225,7 +225,7 @@ static void link( const std::string& cmd, PolarfireTarget* pft ) {
  * pflib::Hcal::elinks and then procede to the commands.
  *
  * ## Commands
- * - RELINK : pflib::PolarfireTarget::elink_relink with verbosity 2
+ * - RELINK : pflib::PolarfireTarget::elink_relink
  * - SPY : pflib::Elinks::spy
  * - BITSLIP : pflib::Elinks::setBitslip and pflib::Elinks::setBitslipAuto
  * - BIGSPY : PolarfireTarget::elinksBigSpy
@@ -240,9 +240,12 @@ static void link( const std::string& cmd, PolarfireTarget* pft ) {
 static void elinks( const std::string& cmd, PolarfireTarget* pft ) {
   pflib::Elinks& elinks=pft->hcal.elinks();
   static int ilink=0;
+  static int min_delay{0}, max_delay{128};
   if (cmd=="RELINK"){
     ilink=BaseMenu::readline_int("Which elink? (-1 for all) ",ilink);
-    pft->elink_relink(ilink,2);
+    min_delay=BaseMenu::readline_int("Min delay? ",min_delay);
+    max_delay=BaseMenu::readline_int("Max delay? ",max_delay);
+    pft->elink_relink(ilink,min_delay,max_delay);
   }
   if (cmd=="SPY") {
     ilink=BaseMenu::readline_int("Which elink? ",ilink);