diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..63cdd31
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,16 @@
+OUT := debugcc
+
+CC=aarch64-linux-gnu-gcc
+
+CFLAGS := -O2 -Wall -g
+LDFLAGS := 
+prefix := /usr/local
+
+SRCS := debugcc.c
+OBJS := $(SRCS:.c=.o)
+
+$(OUT): $(OBJS)
+	$(CC) -o $@ $^ $(LDFLAGS)
+
+clean:
+	rm -f $(OUT) $(OBJS) *-debugcc
diff --git a/debugcc.c b/debugcc.c
new file mode 100644
index 0000000..da34a7d
--- /dev/null
+++ b/debugcc.c
@@ -0,0 +1,352 @@
+/*
+ * Copyright (c) 2019, Linaro Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <sys/mman.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "debugcc.h"
+
+static const struct debugcc_platform *platforms[] = {
+	&qcs404_debugcc,
+	NULL
+};
+
+static uint32_t readl(void *ptr)
+{
+	return *((volatile uint32_t*)ptr);
+}
+
+static void writel(uint32_t val, void *ptr)
+{
+	*((volatile uint32_t*)ptr) = val;
+}
+
+static unsigned int measure_ticks(struct debug_mux *gcc, unsigned int ticks)
+{
+	uint32_t val;
+
+	writel(ticks, gcc->base + gcc->debug_ctl_reg);
+	do {
+		val = readl(gcc->base + gcc->debug_status_reg);
+	} while (val & BIT(25));
+
+	writel(ticks | BIT(20), gcc->base + gcc->debug_ctl_reg);
+	do {
+		val = readl(gcc->base + gcc->debug_status_reg);
+	} while (!(val & BIT(25)));
+
+	val &= 0x1ffffff;
+
+	writel(ticks, gcc->base + gcc->debug_ctl_reg);
+
+	return val;
+}
+
+static void mux_enable(struct debug_mux *mux, int selector, int div)
+{
+	uint32_t val;
+
+	val = readl(mux->base + mux->mux_reg);
+	val &= ~mux->mux_mask;
+	val |= selector << mux->mux_shift;
+	writel(val, mux->base + mux->mux_reg);
+
+	if (mux->div_mask) {
+		val = readl(mux->base + mux->div_reg);
+		val &= ~mux->div_mask;
+		val |= (div - 1) << mux->div_shift;
+		writel(val, mux->base + mux->div_reg);
+	}
+
+	val = readl(mux->base + mux->enable_reg);
+	val |= mux->enable_mask;
+	writel(val, mux->base + mux->enable_reg);
+}
+
+static void mux_disable(struct debug_mux *mux)
+{
+	uint32_t val;
+
+	val = readl(mux->base + mux->enable_reg);
+	val &= ~mux->enable_mask;
+	writel(val, mux->base + mux->enable_reg);
+}
+
+static bool leaf_enabled(struct debug_mux *mux, struct debug_mux *leaf)
+{
+	uint32_t val;
+
+	/* If no AHB clock is specified, we assume it's clocked */
+	if (!leaf || !leaf->ahb_mask)
+		return true;
+
+	val = readl(mux->base + leaf->ahb_reg);
+	val &= leaf->ahb_mask;
+
+	/* CLK_OFF will be set if block is not clocked, so inverse */
+	return !val;
+}
+
+static void measure(const struct measure_clk *clk)
+{
+	unsigned long raw_count_short;
+	unsigned long raw_count_full;
+	struct debug_mux *gcc = clk->primary;
+
+	if (!leaf_enabled(gcc, clk->leaf)) {
+		printf("%50s: skipping\n", clk->name);
+		return;
+	}
+
+	if (clk->leaf)
+		mux_enable(clk->leaf, clk->leaf_mux, clk->leaf_div);
+
+	mux_enable(clk->primary, clk->mux, clk->post_div);
+
+	writel(1, gcc->base + gcc->xo_div4_reg);
+
+	raw_count_short = measure_ticks(gcc, 0x1000);
+	raw_count_full = measure_ticks(gcc, 0x10000);
+
+	writel(0, gcc->base + gcc->xo_div4_reg);
+
+	if (raw_count_full == raw_count_short) {
+		printf("%50s: off\n", clk->name);
+		return;
+	}
+
+	raw_count_full = ((raw_count_full * 10) + 15) * 4800000;
+	raw_count_full = raw_count_full / ((0x10000 * 10) + 35);
+
+	mux_disable(clk->primary);
+
+	if (clk->leaf)
+		mux_disable(clk->leaf);
+
+	if (clk->leaf)
+		raw_count_full *= clk->leaf_div;
+
+	raw_count_full *= clk->post_div;
+
+	if (clk->fixed_div)
+		raw_count_full *= clk->fixed_div;
+
+	printf("%50s: %fMHz (%ldHz)\n", clk->name, raw_count_full / 1000000.0, raw_count_full);
+}
+
+static const struct debugcc_platform *find_platform(const char *name)
+{
+	const struct debugcc_platform **p;
+
+	for (p = platforms; *p; p++) {
+		if (!strcmp((*p)->name, name))
+			return *p;
+	}
+
+	return NULL;
+}
+
+/**
+ * match_platform() - match platform with executable name
+ * @argv: argv[0] of the executable
+ *
+ * Return: A debugcc_platform when a match is found, otherwise NULL
+ *
+ * Matches %s-debugcc against the registered platforms
+ */
+static const struct debugcc_platform *match_platform(const char *argv)
+{
+	const struct debugcc_platform **p;
+	const char *name;
+	size_t len;
+
+	for (p = platforms; *p; p++) {
+		name = (*p)->name;
+
+		len = strlen(name);
+
+		if (!strncmp(name, argv, len) && !strcmp(argv + len, "-debugcc"))
+			return *p;
+	}
+
+	return NULL;
+}
+
+static const struct measure_clk *find_clock(const struct debugcc_platform *platform,
+					    const char *name)
+{
+	const struct measure_clk *clk;
+
+	for (clk = platform->clocks; clk->name; clk++) {
+		if (!strcmp(clk->name, name))
+			return clk;
+	}
+
+	return NULL;
+}
+
+static void list_clocks(const struct debugcc_platform *platform)
+{
+	const struct measure_clk *clk;
+
+	for (clk = platform->clocks; clk->name; clk++)
+		printf("%s\n", clk->name);
+}
+
+static int mmap_mux(int devmem, struct debug_mux *mux)
+{
+	/* Do nothing if this mux has already been mapped */
+	if (!mux || mux->base)
+		return 0;
+
+	mux->base = mmap(0, mux->size, PROT_READ | PROT_WRITE, MAP_SHARED, devmem, mux->phys);
+	if (mux->base == (void *)-1) {
+		warn("failed to map %#zx", mux->phys);
+		return -1;
+	}
+
+	return 0;
+}
+
+/**
+ * mmap_hardware() - loop over all clock and make sure hardware is mmapped
+ * @devmem: file descriptor to an opened /dev/mem
+ * @platform: debugcc_platform with list of clocks to mmap
+ *
+ * Return: 0 on succees, -1 on failure
+ */
+static int mmap_hardware(int devmem, const struct debugcc_platform *platform)
+{
+	const struct measure_clk *clk;
+	int ret;
+
+	for (clk = platform->clocks; clk->name; clk++) {
+		ret = mmap_mux(devmem, clk->primary);
+		if (ret < 0)
+			return ret;
+
+		ret = mmap_mux(devmem, clk->leaf);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void usage(void)
+{
+	const struct debugcc_platform **p;
+
+	fprintf(stderr, "debugcc <-p platform> <-a | -l | clk>\n");
+	fprintf(stderr, "<platform>-debugcc <-a | -l | clk>\n");
+
+	fprintf(stderr, "available platforms:");
+	for (p = platforms; *p; p++)
+		fprintf(stderr, " %s", (*p)->name);
+	fprintf(stderr, "\n");
+
+	exit(0);
+}
+
+int main(int argc, char **argv)
+{
+	const struct debugcc_platform *platform = NULL;
+	const struct measure_clk *clk = NULL;
+	bool do_list_clocks = false;
+	bool all_clocks = false;
+	int devmem;
+	int opt;
+	int ret;
+
+	while ((opt = getopt(argc, argv, "alp:")) != -1) {
+		switch (opt) {
+		case 'a':
+			all_clocks = true;
+			break;
+		case 'l':
+			do_list_clocks = true;
+			break;
+		case 'p':
+			platform = find_platform(optarg);
+			break;
+		default:
+			usage();
+			/* NOTREACHED */
+		}
+	}
+
+	if (!platform) {
+		platform = match_platform(argv[0]);
+		if (!platform)
+			usage();
+	}
+
+	if (do_list_clocks) {
+		list_clocks(platform);
+		exit(0);
+	}
+
+	if (!all_clocks) {
+		if (optind >= argc)
+			usage();
+
+		clk = find_clock(platform, argv[optind]);
+		if (!clk) {
+			fprintf(stderr, "no clock named \"%s\"\n", argv[optind]);
+			exit(1);
+		}
+	}
+
+	devmem = open("/dev/mem", O_RDWR | O_SYNC);
+	if (devmem < 0)
+		err(1, "failed to open /dev/mem");
+
+	ret = mmap_hardware(devmem, platform);
+	if (ret < 0)
+		exit(1);
+
+	if (clk) {
+		measure(clk);
+	} else {
+		for (clk = platform->clocks; clk->name; clk++)
+			measure(clk);
+	}
+
+	return 0;
+}
diff --git a/debugcc.h b/debugcc.h
new file mode 100644
index 0000000..91e9e9d
--- /dev/null
+++ b/debugcc.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2019, Linaro Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef __DEBUGCC_H__
+#define __DEBUGCC_H__
+
+#define BIT(x) (1 << (x))
+
+struct debug_mux {
+	unsigned long phys;
+	void *base;
+	size_t size;
+
+	unsigned int enable_reg;
+	unsigned int enable_mask;
+
+	unsigned int mux_reg;
+	unsigned int mux_mask;
+	unsigned int mux_shift;
+
+	unsigned int div_reg;
+	unsigned int div_shift;
+	unsigned int div_mask;
+
+	unsigned int xo_div4_reg;
+	unsigned int debug_ctl_reg;
+	unsigned int debug_status_reg;
+
+	unsigned int ahb_reg;
+	unsigned int ahb_mask;
+};
+
+struct measure_clk {
+	char *name;
+	struct debug_mux *primary;
+	int mux;
+	int post_div;
+
+	struct debug_mux *leaf;
+	int leaf_mux;
+	int leaf_div;
+
+	unsigned int fixed_div;
+};
+
+struct debugcc_platform {
+	const char *name;
+	const struct measure_clk *clocks;
+};
+
+extern struct debugcc_platform qcs404_debugcc;
+
+#endif