Added user-space counter utility.

- cntr/tools/Makefile: the usual recursive Makefile
- cntr/tools/cntr/Makefile, cntr/tools/cntr/cntr.c: user-space tool to
  periodically read the free-running counter and to calculate frequency
  and deviation from it

cntr/tools/Makefile

@@ -0,0 +1,16 @@
+#
+# tools/Makefile - Build the ATSPI-specific tools
+#
+# Written 2010 by Werner Almesberger
+# Copyright 2010 Werner Almesberger
+#
+# 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.
+#
+
+
+DIRS=cntr
+
+include ../../Makefile.recurse

cntr/tools/cntr/Makefile

@@ -0,0 +1,21 @@
+#
+# cntr/Makefile - Build the CNTR control tool
+#
+# Written 2010 by Werner Almesberger
+# Copyright 2010 Werner Almesberger
+#
+# 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.
+#
+
+
+F32XBASE = ../../../../f32xbase
+
+MAIN = cntr
+OBJS += $(F32XBASE)/lib/usb.o
+
+include $(F32XBASE)/lib/Makefile.common
+
+CFLAGS += -I$(F32XBASE)/include -I../../fw/include -I../include

cntr/tools/cntr/cntr.c

@@ -0,0 +1,225 @@
+/*
+ * cntr/cntr.c - CNTR control tool
+ *
+ * Written 2010 by Werner Almesberger
+ * Copyright 2010 Werner Almesberger
+ *
+ * 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.
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <usb.h>
+#include <sys/time.h>
+
+#include "f32xbase/usb.h"
+#include "cntr/ep0.h"
+#include "cntr/usb-ids.h"
+
+
+#define	FROM_DEV	CNTR_FROM_DEV(0)
+#define	TO_DEV		CNTR_TO_DEV(0)
+
+#define	DEFAULT_CLOCK_DEV_S	0.1	/* 100 ms, typ. NTP over WLAN dev. */
+#define	BUF_SIZE		256
+
+
+
+static void reset_cntr(usb_dev_handle *dev)
+{
+	int res;
+
+	res = usb_control_msg(dev, TO_DEV, CNTR_RESET, 0, 0, NULL, 0, 1000);
+	if (res < 0) {
+		fprintf(stderr, "CNTR_RESET: %d\n", res);
+		exit(1);
+	}
+}
+
+
+static void identify_cntr(usb_dev_handle *dev)
+{
+	const struct usb_device *device = usb_device(dev);
+	uint8_t ids[3];
+	char buf[BUF_SIZE+1];	/* +1 for terminating \0 */
+	int res;
+
+	printf("%04x:%04x ",
+	    device->descriptor.idVendor, device->descriptor.idProduct);
+
+	res = usb_control_msg(dev, FROM_DEV, CNTR_ID, 0, 0,
+	    (char *) ids, sizeof(ids), 1000);
+	if (res < 0) {
+		fprintf(stderr, "CNTR_ID: %s\n", usb_strerror());
+		exit(1);
+	}
+
+	printf("protocol %u.%u hw %u\n", ids[0], ids[1], ids[2]);
+
+	res = usb_control_msg(dev, FROM_DEV, CNTR_BUILD, 0, 0,
+	    buf, sizeof(buf), 1000);
+	if (res < 0) {
+		fprintf(stderr, "CNTR_BUILD: %s\n", usb_strerror());
+		exit(1);
+	}
+	buf[res] = 0;
+	printf("%10s%s\n", "", buf);
+}
+
+
+struct sample {
+	double t0, t1;
+	uint64_t cntr;
+};
+
+
+static void get_sample(usb_dev_handle *dev, struct sample *s)
+{
+	static uint32_t last = 0, high = 0;
+	struct timeval t0, t1;
+	int res;
+	uint8_t buf[4];
+	uint32_t cntr;
+
+	gettimeofday(&t0, NULL);
+	res = usb_control_msg(dev, FROM_DEV, CNTR_READ, 0, 0,
+	    (char *) buf, sizeof(buf), 1000);
+	gettimeofday(&t1, NULL);
+	if (res < 0) {
+		fprintf(stderr, "CNTR_READ: %s\n", usb_strerror());
+		exit(1);
+	}
+	cntr = buf[0] | (buf[1] << 8) | (buf[2] << 16) | (buf[3] << 24);
+	if (last > cntr)
+		high++;
+	last = cntr;
+	s->t0 = t0.tv_sec+t0.tv_usec/1000000.0;
+	s->t1 = t1.tv_sec+t1.tv_usec/1000000.0;
+	s->cntr = (uint64_t) high << 32 | cntr;
+}
+
+
+static void measure(usb_dev_handle *dev, double clock_dev_s)
+{
+	struct sample start, now;
+	uint64_t dc;
+	double dt, f, error;
+	char *f_exp, error_exp;
+
+	get_sample(dev, &start);
+	while (1) {
+		usleep(100000);
+		get_sample(dev, &now);
+		dc = now.cntr-start.cntr;
+		dt = now.t0-start.t0;
+		f = dc/dt;
+		if (f > 1000000.0) {
+			f /= 1000000.0;
+			f_exp = "M";
+		} else if (f > 1000.0) {
+			f /= 1000.0;
+			f_exp = "k";
+		} else {
+			f_exp = "";
+		}
+		if (dc)
+			error = 1.0/dc;			/* one count */
+		else
+			error = 0;
+		error += (start.t1-start.t0)/dt;/* start sample read */
+		error += (now.t1-now.t0)/dt;	/* last sample read */
+		error += clock_dev_s/dt;	/* system clock deviation */
+		if (error > 1) {
+			printf("\r(wait) ");
+			fflush(stdout);
+			continue;
+		}
+
+		error_exp = 'k';
+		error *= 1000.0;	/* ppm */
+		if (error < 1.0) {
+			error_exp = 'm'; /* ppm */
+			error *= 1000.0;
+		}
+		if (error < 1.0) {
+			error_exp = 'b'; /* ppb */
+			error *= 1000.0;
+		}
+		
+		printf("\r%6.1f %1.9f %sHz %3.3f pp%c ",
+		    dt, f, f_exp, error, error_exp);
+		fflush(stdout);
+	}
+}
+
+
+static void usage(const char *name)
+{
+	fprintf(stderr, 
+"usage: %s [clock_dev_s]\n"
+"%6s %s -i\n"
+"%6s %s r\n\n"
+"    clock_dev_s  is the maximum deviation of the system clock, in seconds\n"
+"                 (default: %g s)\n"
+"    -i           identify the CNTR board\n"
+"    -r           reset the CNTR board\n"
+    , name, "", name, "", name, DEFAULT_CLOCK_DEV_S);
+	exit(1);
+}
+
+
+int main(int argc, char *const *argv)
+{
+	usb_dev_handle *dev;
+	int c, identify = 0, reset = 0;
+	double clock_dev_s = DEFAULT_CLOCK_DEV_S;
+	char *end;
+
+	while ((c = getopt(argc, argv, "ir")) != EOF)
+		switch (c) {
+		case 'i':
+			identify = 1;
+			break;
+		case 'r':
+			reset = 1;
+			break;
+		default:
+			usage(*argv);
+		}
+
+	switch (argc-optind) {
+	case 0:
+		break;
+	case 1:
+		clock_dev_s = strtod(argv[optind], &end);
+		if (*end)
+			usage(*argv);
+		break;
+	default:
+		usage(*argv);
+	}
+
+	dev = open_usb(USB_VENDOR, USB_PRODUCT);
+	if (!dev) {
+		fprintf(stderr, ":-(\n");
+		return 1;
+	}
+
+	if (identify) {
+		identify_cntr(dev);
+		return 0;
+	}
+
+	if (reset) {
+		reset_cntr(dev);
+		return 0;
+	}
+
+	measure(dev, clock_dev_s);
+
+	return 0;
+}