[ 1194130 ] busy-loop waiting (breaks compilation of svf.c... wait for next two patches)

git-svn-id: https://urjtag.svn.sourceforge.net/svnroot/urjtag/trunk@704 b68d4a1b-bc3d-0410-92ed-d4ac073336b7

jtag/include/Makefile.am

@@ -39,4 +39,5 @@ noinst_HEADERS = \
 	bssignal.h \
 	state.h \
 	jtag.h \
-	tap.h
+	tap.h \
+	fclock.h

jtag/include/cable.h

@@ -64,7 +64,8 @@ int cable_get_tdo( cable_t *cable );
 int cable_set_trst( cable_t *cable, int trst );
 int cable_get_trst( cable_t *cable );
 
-extern uint32_t frequency;
+void cable_set_frequency( cable_t *cable, uint32_t frequency );
+uint32_t cable_get_frequency( cable_t *cable );
 void cable_wait( void );
 
 extern cable_driver_t *cable_drivers[];

jtag/include/fclock.h

@@ -0,0 +1,47 @@
+/*
+ * fclock.h
+ *
+ * Copyright (C) 2005 Hein Roehrig
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+
+#ifndef FCLOCK_H
+#define FCLOCK_H
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+    
+
+/* return real time in seconds starting at some arbitrary point in
+   time*/
+long double frealtime();
+
+/* return the CPU time used by this process (seconds) */
+long double fcputime();
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif
+

jtag/src/Makefile.am

@@ -63,6 +63,7 @@ jtag_LDADD = \
 	-L../libbrux -lbrux \
 	-Lbus -lbus \
 	-Lsvf -lsvf \
+	-lrt \
 	-lm \
 	@LIBINTL@
 

jtag/src/cmd/frequency.c

@@ -27,6 +27,7 @@
 #include <stdio.h>
 
 #include "cable.h"
+#include "jtag.h"
 
 #include "cmd.h"
 
@@ -36,7 +37,7 @@ cmd_frequency_run( char *params[] )
 	unsigned int freq;
 
 	if (cmd_params( params ) == 1) {
-		printf( _("Current TCK frequency is %u Hz\n"), frequency );
+		printf( _("Current TCK frequency is %u Hz\n"), cable_get_frequency(chain->cable) );
 		return 1;
 	}
 
@@ -47,7 +48,7 @@ cmd_frequency_run( char *params[] )
 		return -1;
 
 	printf( _("Setting TCK frequency to %u Hz\n"), freq );
-	frequency = freq;
+	cable_set_frequency(chain->cable, freq);
 
 	return 1;
 }

jtag/src/lib/Makefile.am

@@ -27,4 +27,5 @@ noinst_LIBRARIES = libjtaglib.a
 
 libjtaglib_a_SOURCES = \
 	getdelim.c \
-	getline.c
+	getline.c \
+	fclock.c

jtag/src/lib/fclock.c

@@ -0,0 +1,86 @@
+/*
+ * fclock.c
+ *
+ * Copyright (C) 2005 Hein Roehrig
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ */
+
+#define _ISOC99_SOURCE
+#define _POSIX_C_SOURCE 199309L
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+#include <sys/times.h>
+#include <math.h>
+#include <assert.h>
+
+
+#ifndef CLK_TCK
+static clock_t CLK_TCK = 0;
+static void set_clk_tck(void) __attribute__ ((constructor));
+static void set_clk_tck(void)
+{
+    long v = sysconf(_SC_CLK_TCK);
+    if (v == -1) {
+        perror("sysconf(_SC_CLK_TCK)");
+        exit(EXIT_FAILURE);
+    }
+    CLK_TCK = v;
+}
+#endif
+
+
+long double
+frealtime()
+{
+    long double result;
+#ifdef _POSIX_TIMERS
+    struct timespec t;    
+    if (clock_gettime(CLOCK_REALTIME, &t)==-1) {
+        perror("frealtime (clock_gettime)");
+        exit(EXIT_FAILURE);
+    }
+    result = (long double)t.tv_sec + (long double)t.tv_nsec*(long double)1e-9;
+#else
+    struct tms t;
+    clock_t c=times(&t);
+    if (c==(clock_t)-1) {
+        perror("frealtime (times)");
+        exit(EXIT_FAILURE);
+    }
+    result = (long double)c/CLK_TCK;
+#endif
+    assert(isnormal(result));
+    assert(result > 0);
+    return result;
+}
+
+
+long double
+fcputime()
+{
+    struct tms t;
+    clock_t c=times(&t);
+    if (c==(clock_t)-1) {
+        perror("fcputime (times)");
+        exit(EXIT_FAILURE);
+    }
+    return ((long double)t.tms_utime+t.tms_stime)/CLK_TCK;
+}
+

jtag/src/tap/cable.c

@@ -28,7 +28,11 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <stdint.h>
+#include <assert.h>
+#include <math.h>
 
+#include "fclock.h"
+#include "jtag.h"
 #include "cable.h"
 
 extern cable_driver_t arcom_cable_driver;
@@ -43,8 +47,6 @@ extern cable_driver_t triton_cable_driver;
 extern cable_driver_t wiggler_cable_driver;
 extern cable_driver_t wiggler2_cable_driver;
 
-uint32_t frequency = 0;
-
 cable_driver_t *cable_drivers[] = {
 	&arcom_cable_driver,
 	&byteblaster_cable_driver,
@@ -102,17 +104,88 @@ cable_get_trst( cable_t *cable )
 	return cable->driver->get_trst( cable );
 }
 
+static uint32_t delay = 0;
+static uint32_t frequency = 0;
+
+void
+cable_set_frequency( cable_t *cable, uint32_t new_frequency )
+{
+	if (new_frequency == 0) {
+		delay = 0;
+		frequency = 0;
+	} else {
+		const double tolerance = 0.1;
+		uint32_t loops;
+
+		printf("requested frequency %u, now calibrating delay loop\n", new_frequency);
+
+		if (delay == 0) {
+			delay = 1000;
+			loops = 10000;
+		} else {
+			loops = 3 * frequency;
+		}
+
+		while (1) {
+			uint32_t i, new_delay;
+			long double start, end, real_frequency;
+
+			start = frealtime();	
+			for (i = 0; i < loops; ++i) {
+				chain_clock(chain, 0, 0);
+			}
+			end = frealtime();
+
+			assert(end > start);
+			real_frequency = (long double)loops / (end - start);
+			printf("new real frequency %Lg, delay %u\n", 
+			       real_frequency, delay);
+
+			loops = 3 * fmax(real_frequency, new_frequency);
+			new_delay = (long double)delay * real_frequency / new_frequency;
+
+			if (real_frequency >= (1.0 - tolerance)*new_frequency) {
+				if (real_frequency <= (1.0 + tolerance)*new_frequency) {
+					break;
+				}
+				if (new_delay > delay) {
+					delay = new_delay;
+				} else {
+					delay++;
+				}
+			} else {
+				if (new_delay < delay) {
+					delay = new_delay;
+				} else {
+					delay--;
+				}			
+				if (delay == 0) {
+					printf("operating without delay\n");
+					break;
+				}
+			}
+		}
+
+		frequency = new_frequency;
+	}
+}
+
+uint32_t
+cable_get_frequency( cable_t *cable )
+{
+	return frequency;
+}
+
 void
 cable_wait( void )
 {
-	useconds_t s;
+	int i;
+	volatile int j;
 
-	if (!frequency)
+	if (delay == 0)
 		return;
 
-	s = 1000000 / frequency / 2;
-	if (s == 0)
-		s = 1;
-
-	usleep( s );
+	for (i = 0; i < delay; ++i) {
+		j = i;
+	}
 }