From 4f36ce4df7a5d26c980042cf893fac5f9de94b8a Mon Sep 17 00:00:00 2001
From: xross <ross@xmos.com>
Date: Wed, 3 Aug 2022 15:11:26 +0100
Subject: [PATCH] * Sync mode: added basic move to internal clock when SOF
 clock not available (not change over on plug event is not smooth) * Sync
 mode: Removed use of float

---
 lib_xua/src/core/buffer/ep/ep_buffer.xc | 31 ++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/lib_xua/src/core/buffer/ep/ep_buffer.xc b/lib_xua/src/core/buffer/ep/ep_buffer.xc
index d5d4db32..ec96c1f3 100644
--- a/lib_xua/src/core/buffer/ep/ep_buffer.xc
+++ b/lib_xua/src/core/buffer/ep/ep_buffer.xc
@@ -3,8 +3,7 @@
 #include "xua.h"
 #if XUA_USB_EN
 #include <xs1.h>
-#include <print.h>
-
+#include <stdint.h>
 
 #ifdef MIDI
 #include "usb_midi.h"
@@ -357,7 +356,17 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
 #endif
 #endif
 
-    timer tmr;
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+#define LOCAL_CLOCK_INCREMENT       100000  /* 500Hz */
+#define LOCAL_CLOCK_MARGIN          1000
+    int sofClockValid = 0;
+    timer t_sofCheck;
+    unsigned timeLastEdge;
+    unsigned timeNextEdge;
+    t_sofCheck :> timeLastEdge;
+    timeNextEdge + LOCAL_CLOCK_INCREMENT;
+    i_pll_ref.toggle();
+#endif
 
     while(1)
     {
@@ -501,6 +510,14 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
                     SET_SHARED_GLOBAL(g_freqChange_flag, cmd);  /* Set Flag */
                 }
                 break;
+#if (XUA_SYNCMODE == XUA_SYNCMODE_SYNC)
+            case t_sofCheck when timerafter(timeNextEdge) :> void:
+                i_pll_ref.toggle();
+                timeLastEdge = timeNextEdge;
+                timeNextEdge += LOCAL_CLOCK_INCREMENT;
+                break;
+#endif
+
             }
 
             #define MASK_16_13            (7)   /* Bits that should not be transmitted as part of feedback */
@@ -517,12 +534,11 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
                 int framesPerSec;
                 GET_SHARED_GLOBAL(usbSpeed, g_curUsbSpeed);
                 static int sofCount = 0;
-                static unsigned syncPinVal = 0;
 
                 framesPerSec = (usbSpeed == XUD_SPEED_HS) ? 8000 : 1000;
-                float float_clocks = (float) sampleFreq/framesPerSec ;
 
-                clocks = (unsigned) (float_clocks * (1 << 16));
+                clocks =  ((int64_t) sampleFreq << 16) / framesPerSec;
+
                 asm volatile("stw %0, dp[g_speed]"::"r"(clocks));
 
                 sofCount += 1000;
@@ -530,7 +546,9 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
                 {
                     /* Port is accessed via interface to allow flexibilty with location */
                     i_pll_ref.toggle();
+                    t_sofCheck :> timeLastEdge;
                     sofCount = 0;
+                    timeNextEdge = timeLastEdge + LOCAL_CLOCK_INCREMENT + LOCAL_CLOCK_MARGIN;
                 }
 #else
 
@@ -889,6 +907,7 @@ void XUA_Buffer_Ep(register chanend c_aud_out,
             case XUD_SetData_Select(c_hid, ep_hid, result):
                 hid_ready_flag = 0U;
                 unsigned reportTime;
+                timer tmr;
                 tmr :> reportTime;
                 hidCaptureReportTime(hid_ready_id, reportTime);
                 hidCalcNextReportTime(hid_ready_id);