diff --git a/tools/Makefile b/tools/Makefile
index dd6c518..356c83b 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -11,8 +11,8 @@
 #
 
 
-BEN_DIRS=atrf-id atrf-path atrf-proxy atrf-reset atrf-rssi atrf-trim \
-	 atrf-txrx atrf-xmit atrf-xtal
+BEN_DIRS=atrf-gpio atrf-id atrf-path atrf-proxy atrf-reset \
+	 atrf-rssi atrf-trim atrf-txrx atrf-xmit atrf-xtal
 DIRS=$(BEN_DIRS) usbwait
 TARGET_ONLY_DIRS=lib
 
diff --git a/tools/atrf-gpio/Makefile b/tools/atrf-gpio/Makefile
new file mode 100644
index 0000000..a626159
--- /dev/null
+++ b/tools/atrf-gpio/Makefile
@@ -0,0 +1,31 @@
+#
+# atrf-gpio/Makefile - Build the GPIO test utility
+#
+# Written 2010, 2011 by Werner Almesberger
+# Copyright 2010, 2011 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.
+#
+
+
+MAIN = atrf-gpio
+
+include ../Makefile.common
+
+MACROS_host += -DHAVE_ATUSB
+OBJS_host = atusb.o
+
+MACROS_ben_openwrt += -DHAVE_ATBEN
+OBJS_ben_openwrt = atben.o
+
+MACROS_ben_jlime += -DHAVE_ATBEN
+OBJS_ben_jlime = atben.o
+
+
+$(MAIN):        $(OBJS_$(TARGET))
+
+clean::
+		rm -f $(OBJS_host) $(OBJS_ben_openwrt) $(OBJS_ben_jlime)
diff --git a/tools/atrf-gpio/atben.c b/tools/atrf-gpio/atben.c
new file mode 100644
index 0000000..23cc253
--- /dev/null
+++ b/tools/atrf-gpio/atben.c
@@ -0,0 +1,185 @@
+/*
+ * atrf-gpio/atben.c - ATBEN-specific GPIO driver
+ *
+ * Written 2011 by Werner Almesberger
+ * Copyright 2011 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 <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "at86rf230.h"
+#include "atrf.h"
+
+#include "atrf-gpio.h"
+
+
+static struct pin {
+	const char *name;
+	int bit;
+} pins[] = {
+	{ "SCLK",	11 },
+	{ "MISO",	10 },
+	{ "SLP_TR",	 9 },
+	{ "MOSI",	 8 },
+	{ "nSEL",	13 },
+	{ "IRQ",	12 },
+	{ NULL,		 0 }
+};
+
+static uint32_t orig_dat, orig_pe, orig_dir;
+static uint32_t changed = 0;
+
+
+/* ----- Ben hardware ------------------------------------------------------ */
+
+
+static volatile uint32_t *pdpin, *pddat, *pddats, *pddatc;
+static volatile uint32_t *pdpe, *pdpes, *pdpec;
+static volatile uint32_t *pddir, *pddirs, *pddirc;
+
+
+static void ben_setup(struct atrf_dsc *dsc)
+{
+	volatile void *base = atrf_ben_regs(dsc);
+
+	pdpin = base+0x10300;
+	pddat = base+0x10310;
+	pddats = base+0x10314;
+	pddatc = base+0x10318;
+
+	pdpe = base+0x10330;
+	pdpes = base+0x10334;
+	pdpec = base+0x10338;
+
+	pddir = base+0x10360;
+	pddirs = base+0x10364;
+	pddirc = base+0x10368;
+}
+
+
+/* ----- Diagnostic dump --------------------------------------------------- */
+
+
+static char decode_cfg(uint32_t bit)
+{
+	if (*pddir & bit)
+		return *pddat & bit ? '1' : '0';
+	return *pdpe & bit ? 'Z' : 'P';
+}
+
+
+static void dump_pd(uint32_t expect, uint32_t got, uint32_t mask)
+{
+	const struct pin *pin;
+
+	fprintf(stderr, "name\tcfg exp got\n");
+	for (pin = pins; pin->name; pin++) {
+		uint32_t bit = 1 << pin->bit;
+
+		fprintf(stderr, "%s\t%c   %d   %d",
+		    pin->name, decode_cfg(bit),
+		    !!(expect & bit), !!(got & bit));
+		if ((expect ^ got) & mask & bit)
+			fprintf(stderr, "\t***");
+		fputc('\n', stderr);
+	}
+}
+
+
+static void restore_gpios(void)
+{
+	*pddats = orig_dat & changed;
+	*pddatc = ~orig_dat & changed;
+	*pdpes = orig_pe & changed;
+	*pdpec = ~orig_pe & changed;
+	*pddirs = orig_dir & changed;
+	*pddirc = ~orig_dir & changed;
+}
+
+
+/* ----- Decode and apply pattern ------------------------------------------ */
+
+
+void do_atben(struct atrf_dsc *dsc, const char *pattern, const char *next)
+{
+	static int first = 1;
+	uint32_t read = 0, expect = 0;
+	const struct pin *pin = pins;
+	uint32_t got;
+	const char *p;
+
+	if (first) {
+		ben_setup(dsc);
+		orig_dat = *pddat;
+		orig_pe = *pdpe;
+		orig_dir = *pddir;
+		atexit(restore_gpios);
+
+		first = 0;
+	}
+
+	for (p = pattern; *p; p++) {
+		uint32_t bit;
+
+		if (!pin->name) {
+			fprintf(stderr, "too many pins in \"%s\"\n", pattern);
+			exit(1);
+		}
+		bit = 1 << pin->bit;
+		switch (*p) {
+		case '0':
+			*pddatc = bit;
+			*pddirs = bit;
+			break;
+		case '1':
+			*pddats = bit;
+			*pddirs = bit;
+			break;
+		case 'H':
+			expect |= bit;
+			/* fall through */
+		case 'L':
+			read |= bit;
+			/* fall through */
+		case 'Z':
+			*pdpec = bit;
+			*pddirc = bit;
+			break;
+		case 'h':
+			expect |= bit;
+			/* fall through */
+		case 'l':
+			read |= bit;
+			/* fall through */
+		case 'z':
+			*pddirc = bit;
+			*pdpes = bit;
+			break;
+		case 'x':
+			pin++;
+			continue;
+		default:
+			continue;
+		}
+		changed |= bit;
+		pin++;
+	}
+
+	usleep(1000);
+
+	got = *pdpin;
+	if ((got & read) != expect) {
+		dump_pd(expect, got, read);
+		fprintf(stderr, "at \"%s\", next \"%s\"\n", pattern, next);
+		exit(1);
+	}
+}
diff --git a/tools/atrf-gpio/atrf-gpio.c b/tools/atrf-gpio/atrf-gpio.c
new file mode 100644
index 0000000..d2f5042
--- /dev/null
+++ b/tools/atrf-gpio/atrf-gpio.c
@@ -0,0 +1,204 @@
+/*
+ * atrf-gpio/atrf-gpio.c - ATBEN/ATUSB GPIO test
+ *
+ * Written 2011 by Werner Almesberger
+ * Copyright 2011 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 <unistd.h>
+#include <string.h>
+
+#include "at86rf230.h"
+#include "atrf.h"
+
+#include "atrf-gpio.h"
+
+
+static void atben(struct atrf_dsc *dsc, const char *pattern, const char *next)
+{
+#ifdef HAVE_ATBEN
+	do_atben(dsc, pattern, next);
+#else
+	fprintf(stderr, "not compiled with ATBEN support\n");
+	exit(1);
+#endif
+}
+
+
+static void atusb(struct atrf_dsc *dsc, const char *pattern, const char *next)
+{
+#ifdef HAVE_ATUSB
+	do_atusb(dsc, pattern, next);
+#else
+	fprintf(stderr, "not compiled with ATUSB support\n");
+	exit(1);
+#endif
+}
+
+
+static void bad_reg_op(const char *arg)
+{
+	fprintf(stderr, "invalid operation \"%s\"\n", arg);
+	exit(1);
+}
+
+
+static int reg_op(struct atrf_dsc *dsc, const char *arg, int doit)
+{
+	const char *p;
+	char *end;
+	unsigned long reg, value;
+	uint8_t got;
+
+	p = strchr(arg, '=');
+	if (!p)
+		p = strchr(arg, ':');
+	if (!p)
+		p = strchr(arg, '!');
+	if (!p)
+		p = strchr(arg, '/');
+	if (!p)
+		return 0;
+	reg = strtoul(arg, &end, 0);
+	if (end != p || reg > 0xff)
+		bad_reg_op(arg);
+	value = strtoul(p+1, &end, 0);
+	if (*end || value > 0xff)
+		bad_reg_op(arg);
+	if (!doit)
+		return 1;
+	switch (*p) {
+	case '=':
+		atrf_reg_write(dsc, reg, value);
+		break;
+	case ':':
+		got = atrf_reg_read(dsc, reg);
+		if (end != p+1 && got != value) {
+			fprintf(stderr,
+			    "register 0x%02lx: got 0x%02x expected 0x%02lx\n",
+			    reg, got, value);
+			exit(1);
+		}
+		break;
+	case '!':
+		atrf_sram_write(dsc, reg, value);
+		break;
+	case '/':
+		got = atrf_sram_read(dsc, reg);
+		if (got != value) {
+			fprintf(stderr,
+			    "got 0x%02x expected 0x%02lx\n", got, value);
+			exit(1);
+		}
+		break;
+	default:
+		abort();
+	}
+	return 1;
+}
+
+
+static void usage(const char *name)
+{
+	fprintf(stderr,
+"usage: %s [-d driver[:arg]] command|pattern ...\n"
+"  -d driver[:arg]  use the specified driver (default: %s)\n\n"
+"  command is one of:\n"
+"    reg=value    set transceiver register\n"
+"    reg:[value]  read transceiver register and (optionally) verify value\n"
+"    addr!value   write one byte to SRAM\n"
+"    addr/value   read and verify one byte from SRAM\n"
+"    #...         comment\n\n"
+"  pattern is a sequence of the following characters:\n"
+"    0 = output a strong 0             1 = output a strong 1\n"
+"    L = pull up, expect to read 0     H = pull up, expect to read 1\n"
+"    l = no pull-up, expect to read 0  h = no pull-up, expect to read 1\n"
+"    Z = pull up, don't read           z = no pull-up, don't read\n"
+"    x = don't care                    . = separator\n"
+    , name, atrf_default_driver_name());
+	exit(1);
+}
+
+
+/*
+ * 0	strong 0 out
+ * 1	strong 1 out
+ * H	pull-up, read 1
+ * L	pull-up, read 0
+ * h	no pull-up, read 1
+ * l	no pull-up, read 0
+ * Z	pull-up, don't read
+ * z	no pull-up, don't read
+ * x	don't care
+ * .	separator
+ */
+
+
+int main(int argc, char *const *argv)
+{
+	const char *driver = NULL;
+	struct atrf_dsc *dsc;
+	int trx_off = 1;
+	int c, i;
+	const char *s;
+
+	while ((c = getopt(argc, argv, "d:p")) != EOF)
+		switch (c) {
+		case 'd':
+			driver = optarg;
+			break;
+		case 'p':
+			trx_off = 0;
+			break;
+		default:
+			usage(*argv);
+		}
+
+	for (i = optind; i != argc; i++) {
+		if (*argv[i] == '#')
+			continue;
+		if (reg_op(NULL, argv[i], 0))
+			continue;
+		for (s = argv[i]; *s; s++)
+			if (!strchr("01HLhlZzx.", *s))
+				fprintf(stderr,
+				    "invalid configuration '%c' in \"%s\"\n",
+				    *s, argv[i]);
+	}
+
+	dsc = atrf_open(driver);
+	if (!dsc)
+		return 1;
+
+	atrf_reset_rf(dsc);
+
+	if (trx_off) {
+		atrf_reg_write(dsc, REG_TRX_STATE, TRX_CMD_TRX_OFF);
+		do usleep(100);
+		while ((atrf_reg_read(dsc, REG_TRX_STATUS) & TRX_STATUS_MASK)
+		    != TRX_STATUS_TRX_OFF);
+	}
+
+	for (i = optind; i != argc; i++) {
+		if (*argv[i] == '#')
+			continue;
+		if (reg_op(dsc, argv[i], 1))
+			continue;
+		if (atrf_usb_handle(dsc))
+			atusb(dsc, argv[i], argv[i+1]);
+		else
+			atben(dsc, argv[i], argv[i+1]);
+	}
+
+//	atrf_close(dsc);
+
+	return 0;
+}
diff --git a/tools/atrf-gpio/atrf-gpio.h b/tools/atrf-gpio/atrf-gpio.h
new file mode 100644
index 0000000..ad7389a
--- /dev/null
+++ b/tools/atrf-gpio/atrf-gpio.h
@@ -0,0 +1,23 @@
+/*
+ * atrf-gpio/atrf-gpio.h - ATBEN/ATUSB GPIO test
+ *
+ * Written 2011 by Werner Almesberger
+ * Copyright 2011 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.
+ */
+
+
+#ifndef ATRF_GPIO_H
+#define	ATRF_GPIO_H
+
+#include "atrf.h"
+
+
+void do_atben(struct atrf_dsc *dsc, const char *pattern, const char *next);
+void do_atusb(struct atrf_dsc *dsc, const char *pattern, const char *next);
+
+#endif /* !ATRF_GPIO_H */
diff --git a/tools/atrf-gpio/atusb.c b/tools/atrf-gpio/atusb.c
new file mode 100644
index 0000000..12d5f2b
--- /dev/null
+++ b/tools/atrf-gpio/atusb.c
@@ -0,0 +1,27 @@
+/*
+ * atrf-gpio/atusb.c - ATUSB-specific GPIO driver
+ *
+ * Written 2011 by Werner Almesberger
+ * Copyright 2011 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 "atrf.h"
+
+#include "atrf-gpio.h"
+
+
+/* ----- Decode and apply pattern ------------------------------------------ */
+
+
+void do_atusb(struct atrf_dsc *dsc, const char *pattern, const char *next)
+{
+	abort();
+}