diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
new file mode 100644
index 0000000..1dffabe
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
@@ -0,0 +1,53 @@
+What:		/sys/bus/coresight/devices/<memory_map>.stm/enable_source
+Date:		April 2016
+KernelVersion:	4.7
+Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>
+Description:	(RW) Enable/disable tracing on this specific trace macrocell.
+		Enabling the trace macrocell implies it has been configured
+		properly and a sink has been identified for it.  The path
+		of coresight components linking the source to the sink is
+		configured and managed automatically by the coresight framework.
+
+What:		/sys/bus/coresight/devices/<memory_map>.stm/hwevent_enable
+Date:		April 2016
+KernelVersion:	4.7
+Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>
+Description:	(RW) Provides access to the HW event enable register, used in
+		conjunction with HW event bank select register.
+
+What:		/sys/bus/coresight/devices/<memory_map>.stm/hwevent_select
+Date:		April 2016
+KernelVersion:	4.7
+Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>
+Description:	(RW) Gives access to the HW event block select register
+		(STMHEBSR) in order to configure up to 256 channels.  Used in
+		conjunction with "hwevent_enable" register as described above.
+
+What:		/sys/bus/coresight/devices/<memory_map>.stm/port_enable
+Date:		April 2016
+KernelVersion:	4.7
+Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>
+Description:	(RW) Provides access to the stimulus port enable register
+		(STMSPER).  Used in conjunction with "port_select" described
+		below.
+
+What:		/sys/bus/coresight/devices/<memory_map>.stm/port_select
+Date:		April 2016
+KernelVersion:	4.7
+Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>
+Description:	(RW) Used to determine which bank of stimulus port bit in
+		register STMSPER (see above) apply to.
+
+What:		/sys/bus/coresight/devices/<memory_map>.stm/status
+Date:		April 2016
+KernelVersion:	4.7
+Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>
+Description:	(R) List various control and status registers.  The specific
+		layout and content is driver specific.
+
+What:		/sys/bus/coresight/devices/<memory_map>.stm/traceid
+Date:		April 2016
+KernelVersion:	4.7
+Contact:	Mathieu Poirier <mathieu.poirier@linaro.org>
+Description:	(RW) Holds the trace ID that will appear in the trace stream
+		coming from this trace entity.
diff --git a/Documentation/trace/coresight.txt b/Documentation/trace/coresight.txt
index 0a5c329..a33c88c 100644
--- a/Documentation/trace/coresight.txt
+++ b/Documentation/trace/coresight.txt
@@ -190,8 +190,8 @@ expected to be accessed and controlled using those entries.
 Last but not least, "struct module *owner" is expected to be set to reflect
 the information carried in "THIS_MODULE".
 
-How to use
-----------
+How to use the tracer modules
+-----------------------------
 
 Before trace collection can start, a coresight sink needs to be identify.
 There is no limit on the amount of sinks (nor sources) that can be enabled at
@@ -297,3 +297,36 @@ Info                                    Tracing enabled
 Instruction     13570831        0x8026B584      E28DD00C        false   ADD      sp,sp,#0xc
 Instruction     0       0x8026B588      E8BD8000        true    LDM      sp!,{pc}
 Timestamp                                       Timestamp: 17107041535
+
+How to use the STM module
+-------------------------
+
+Using the System Trace Macrocell module is the same as the tracers - the only
+difference is that clients are driving the trace capture rather
+than the program flow through the code.
+
+As with any other CoreSight component, specifics about the STM tracer can be
+found in sysfs with more information on each entry being found in [1]:
+
+root@genericarmv8:~# ls /sys/bus/coresight/devices/20100000.stm
+enable_source   hwevent_select  port_enable     subsystem       uevent
+hwevent_enable  mgmt            port_select     traceid
+root@genericarmv8:~#
+
+Like any other source a sink needs to be identified and the STM enabled before
+being used:
+
+root@genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20010000.etf/enable_sink
+root@genericarmv8:~# echo 1 > /sys/bus/coresight/devices/20100000.stm/enable_source
+
+From there user space applications can request and use channels using the devfs
+interface provided for that purpose by the generic STM API:
+
+root@genericarmv8:~# ls -l /dev/20100000.stm
+crw-------    1 root     root       10,  61 Jan  3 18:11 /dev/20100000.stm
+root@genericarmv8:~#
+
+Details on how to use the generic STM API can be found here [2].
+
+[1]. Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
+[2]. Documentation/trace/stm.txt
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index db05410..130cb21 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -78,4 +78,15 @@ config CORESIGHT_QCOM_REPLICATOR
 	  programmable ATB replicator sends the ATB trace stream from the
 	  ETB/ETF to the TPIUi and ETR.
 
+config CORESIGHT_STM
+	bool "CoreSight System Trace Macrocell driver"
+	depends on (ARM && !(CPU_32v3 || CPU_32v4 || CPU_32v4T)) || ARM64
+	select CORESIGHT_LINKS_AND_SINKS
+	select STM
+	help
+	  This driver provides support for hardware assisted software
+	  instrumentation based tracing. This is primarily used for
+	  logging useful software events or data coming from various entities
+	  in the system, possibly running different OSs
+
 endif
diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 1d0e32c..c6f84b5 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_CORESIGHT_SOURCE_ETM3X) += coresight-etm3x.o coresight-etm-cp14.o \
 obj-$(CONFIG_CORESIGHT_SOURCE_ETM4X) += coresight-etm4x.o \
 					coresight-etm4x-sysfs.o
 obj-$(CONFIG_CORESIGHT_QCOM_REPLICATOR) += coresight-replicator-qcom.o
+obj-$(CONFIG_CORESIGHT_STM) += coresight-stm.o
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
new file mode 100644
index 0000000..0e8e79a
--- /dev/null
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -0,0 +1,918 @@
+/* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved.
+ *
+ * Description: CoreSight System Trace Macrocell driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * Initial implementation by Pratik Patel
+ * (C) 2014-2015 Pratik Patel <pratikp@codeaurora.org>
+ *
+ * Serious refactoring, code cleanup and upgrading to the Coresight upstream
+ * framework by Mathieu Poirier
+ * (C) 2015-2016 Mathieu Poirier <mathieu.poirier@linaro.org>
+ *
+ * Guaranteed timing and support for various packet type coming from the
+ * generic STM API by Chunyan Zhang
+ * (C) 2015-2016 Chunyan Zhang <zhang.chunyan@linaro.org>
+ */
+#include <asm/local.h>
+#include <linux/amba/bus.h>
+#include <linux/bitmap.h>
+#include <linux/clk.h>
+#include <linux/coresight.h>
+#include <linux/coresight-stm.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/moduleparam.h>
+#include <linux/of_address.h>
+#include <linux/perf_event.h>
+#include <linux/pm_runtime.h>
+#include <linux/stm.h>
+
+#include "coresight-priv.h"
+
+#define STMDMASTARTR			0xc04
+#define STMDMASTOPR			0xc08
+#define STMDMASTATR			0xc0c
+#define STMDMACTLR			0xc10
+#define STMDMAIDR			0xcfc
+#define STMHEER				0xd00
+#define STMHETER			0xd20
+#define STMHEBSR			0xd60
+#define STMHEMCR			0xd64
+#define STMHEMASTR			0xdf4
+#define STMHEFEAT1R			0xdf8
+#define STMHEIDR			0xdfc
+#define STMSPER				0xe00
+#define STMSPTER			0xe20
+#define STMPRIVMASKR			0xe40
+#define STMSPSCR			0xe60
+#define STMSPMSCR			0xe64
+#define STMSPOVERRIDER			0xe68
+#define STMSPMOVERRIDER			0xe6c
+#define STMSPTRIGCSR			0xe70
+#define STMTCSR				0xe80
+#define STMTSSTIMR			0xe84
+#define STMTSFREQR			0xe8c
+#define STMSYNCR			0xe90
+#define STMAUXCR			0xe94
+#define STMSPFEAT1R			0xea0
+#define STMSPFEAT2R			0xea4
+#define STMSPFEAT3R			0xea8
+#define STMITTRIGGER			0xee8
+#define STMITATBDATA0			0xeec
+#define STMITATBCTR2			0xef0
+#define STMITATBID			0xef4
+#define STMITATBCTR0			0xef8
+
+#define STM_32_CHANNEL			32
+#define BYTES_PER_CHANNEL		256
+#define STM_TRACE_BUF_SIZE		4096
+#define STM_SW_MASTER_END		127
+
+/* Register bit definition */
+#define STMTCSR_BUSY_BIT		23
+/* Reserve the first 10 channels for kernel usage */
+#define STM_CHANNEL_OFFSET		0
+
+enum stm_pkt_type {
+	STM_PKT_TYPE_DATA	= 0x98,
+	STM_PKT_TYPE_FLAG	= 0xE8,
+	STM_PKT_TYPE_TRIG	= 0xF8,
+};
+
+#define stm_channel_addr(drvdata, ch)	(drvdata->chs.base +	\
+					(ch * BYTES_PER_CHANNEL))
+#define stm_channel_off(type, opts)	(type & ~opts)
+
+static int boot_nr_channel;
+
+/*
+ * Not really modular but using module_param is the easiest way to
+ * remain consistent with existing use cases for now.
+ */
+module_param_named(
+	boot_nr_channel, boot_nr_channel, int, S_IRUGO
+);
+
+/**
+ * struct channel_space - central management entity for extended ports
+ * @base:		memory mapped base address where channels start.
+ * @guaraneed:		is the channel delivery guaranteed.
+ */
+struct channel_space {
+	void __iomem		*base;
+	unsigned long		*guaranteed;
+};
+
+/**
+ * struct stm_drvdata - specifics associated to an STM component
+ * @base:		memory mapped base address for this component.
+ * @dev:		the device entity associated to this component.
+ * @atclk:		optional clock for the core parts of the STM.
+ * @csdev:		component vitals needed by the framework.
+ * @spinlock:		only one at a time pls.
+ * @chs:		the channels accociated to this STM.
+ * @stm:		structure associated to the generic STM interface.
+ * @mode:		this tracer's mode, i.e sysFS, or disabled.
+ * @traceid:		value of the current ID for this component.
+ * @write_bytes:	Maximus bytes this STM can write at a time.
+ * @stmsper:		settings for register STMSPER.
+ * @stmspscr:		settings for register STMSPSCR.
+ * @numsp:		the total number of stimulus port support by this STM.
+ * @stmheer:		settings for register STMHEER.
+ * @stmheter:		settings for register STMHETER.
+ * @stmhebsr:		settings for register STMHEBSR.
+ */
+struct stm_drvdata {
+	void __iomem		*base;
+	struct device		*dev;
+	struct clk		*atclk;
+	struct coresight_device	*csdev;
+	spinlock_t		spinlock;
+	struct channel_space	chs;
+	struct stm_data		stm;
+	local_t			mode;
+	u8			traceid;
+	u32			write_bytes;
+	u32			stmsper;
+	u32			stmspscr;
+	u32			numsp;
+	u32			stmheer;
+	u32			stmheter;
+	u32			stmhebsr;
+};
+
+static void stm_hwevent_enable_hw(struct stm_drvdata *drvdata)
+{
+	CS_UNLOCK(drvdata->base);
+
+	writel_relaxed(drvdata->stmhebsr, drvdata->base + STMHEBSR);
+	writel_relaxed(drvdata->stmheter, drvdata->base + STMHETER);
+	writel_relaxed(drvdata->stmheer, drvdata->base + STMHEER);
+	writel_relaxed(0x01 |	/* Enable HW event tracing */
+		       0x04,	/* Error detection on event tracing */
+		       drvdata->base + STMHEMCR);
+
+	CS_LOCK(drvdata->base);
+}
+
+static void stm_port_enable_hw(struct stm_drvdata *drvdata)
+{
+	CS_UNLOCK(drvdata->base);
+	/* ATB trigger enable on direct writes to TRIG locations */
+	writel_relaxed(0x10,
+		       drvdata->base + STMSPTRIGCSR);
+	writel_relaxed(drvdata->stmspscr, drvdata->base + STMSPSCR);
+	writel_relaxed(drvdata->stmsper, drvdata->base + STMSPER);
+
+	CS_LOCK(drvdata->base);
+}
+
+static void stm_enable_hw(struct stm_drvdata *drvdata)
+{
+	if (drvdata->stmheer)
+		stm_hwevent_enable_hw(drvdata);
+
+	stm_port_enable_hw(drvdata);
+
+	CS_UNLOCK(drvdata->base);
+
+	/* 4096 byte between synchronisation packets */
+	writel_relaxed(0xFFF, drvdata->base + STMSYNCR);
+	writel_relaxed((drvdata->traceid << 16 | /* trace id */
+			0x02 |			 /* timestamp enable */
+			0x01),			 /* global STM enable */
+			drvdata->base + STMTCSR);
+
+	CS_LOCK(drvdata->base);
+}
+
+static int stm_enable(struct coresight_device *csdev,
+		      struct perf_event_attr *attr, u32 mode)
+{
+	u32 val;
+	struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	if (mode != CS_MODE_SYSFS)
+		return -EINVAL;
+
+	val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
+
+	/* Someone is already using the tracer */
+	if (val)
+		return -EBUSY;
+
+	pm_runtime_get_sync(drvdata->dev);
+
+	spin_lock(&drvdata->spinlock);
+	stm_enable_hw(drvdata);
+	spin_unlock(&drvdata->spinlock);
+
+	dev_info(drvdata->dev, "STM tracing enabled\n");
+	return 0;
+}
+
+static void stm_hwevent_disable_hw(struct stm_drvdata *drvdata)
+{
+	CS_UNLOCK(drvdata->base);
+
+	writel_relaxed(0x0, drvdata->base + STMHEMCR);
+	writel_relaxed(0x0, drvdata->base + STMHEER);
+	writel_relaxed(0x0, drvdata->base + STMHETER);
+
+	CS_LOCK(drvdata->base);
+}
+
+static void stm_port_disable_hw(struct stm_drvdata *drvdata)
+{
+	CS_UNLOCK(drvdata->base);
+
+	writel_relaxed(0x0, drvdata->base + STMSPER);
+	writel_relaxed(0x0, drvdata->base + STMSPTRIGCSR);
+
+	CS_LOCK(drvdata->base);
+}
+
+static void stm_disable_hw(struct stm_drvdata *drvdata)
+{
+	u32 val;
+
+	CS_UNLOCK(drvdata->base);
+
+	val = readl_relaxed(drvdata->base + STMTCSR);
+	val &= ~0x1; /* clear global STM enable [0] */
+	writel_relaxed(val, drvdata->base + STMTCSR);
+
+	CS_LOCK(drvdata->base);
+
+	stm_port_disable_hw(drvdata);
+	if (drvdata->stmheer)
+		stm_hwevent_disable_hw(drvdata);
+}
+
+static void stm_disable(struct coresight_device *csdev)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	/*
+	 * For as long as the tracer isn't disabled another entity can't
+	 * change its status.  As such we can read the status here without
+	 * fearing it will change under us.
+	 */
+	if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
+		spin_lock(&drvdata->spinlock);
+		stm_disable_hw(drvdata);
+		spin_unlock(&drvdata->spinlock);
+
+		/* Wait until the engine has completely stopped */
+		coresight_timeout(drvdata, STMTCSR, STMTCSR_BUSY_BIT, 0);
+
+		pm_runtime_put(drvdata->dev);
+
+		local_set(&drvdata->mode, CS_MODE_DISABLED);
+		dev_info(drvdata->dev, "STM tracing disabled\n");
+	}
+}
+
+static int stm_trace_id(struct coresight_device *csdev)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+
+	return drvdata->traceid;
+}
+
+static const struct coresight_ops_source stm_source_ops = {
+	.trace_id	= stm_trace_id,
+	.enable		= stm_enable,
+	.disable	= stm_disable,
+};
+
+static const struct coresight_ops stm_cs_ops = {
+	.source_ops	= &stm_source_ops,
+};
+
+static inline bool stm_addr_unaligned(const void *addr, u8 write_bytes)
+{
+	return ((unsigned long)addr & (write_bytes - 1));
+}
+
+static void stm_send(void *addr, const void *data, u32 size, u8 write_bytes)
+{
+	u8 paload[8];
+
+	if (stm_addr_unaligned(data, write_bytes)) {
+		memcpy(paload, data, size);
+		data = paload;
+	}
+
+	/* now we are 64bit/32bit aligned */
+	switch (size) {
+	case 8:
+		writeq_relaxed(*(u64 *)data, addr);
+		break;
+	case 4:
+		writel_relaxed(*(u32 *)data, addr);
+		break;
+	case 2:
+		writew_relaxed(*(u16 *)data, addr);
+		break;
+	case 1:
+		writeb_relaxed(*(u8 *)data, addr);
+		break;
+	default:
+		break;
+	}
+}
+
+static int stm_generic_link(struct stm_data *stm_data,
+			    unsigned int master,  unsigned int channel)
+{
+	struct stm_drvdata *drvdata = container_of(stm_data,
+						   struct stm_drvdata, stm);
+	if (!drvdata || !drvdata->csdev)
+		return -EINVAL;
+
+	return coresight_enable(drvdata->csdev);
+}
+
+static void stm_generic_unlink(struct stm_data *stm_data,
+			       unsigned int master,  unsigned int channel)
+{
+	struct stm_drvdata *drvdata = container_of(stm_data,
+						   struct stm_drvdata, stm);
+	if (!drvdata || !drvdata->csdev)
+		return;
+
+	stm_disable(drvdata->csdev);
+}
+
+static long stm_generic_set_options(struct stm_data *stm_data,
+				    unsigned int master,
+				    unsigned int channel,
+				    unsigned int nr_chans,
+				    unsigned long options)
+{
+	struct stm_drvdata *drvdata = container_of(stm_data,
+						   struct stm_drvdata, stm);
+	if (!(drvdata && local_read(&drvdata->mode)))
+		return -EINVAL;
+
+	if (channel >= drvdata->numsp)
+		return -EINVAL;
+
+	switch (options) {
+	case STM_OPTION_GUARANTEED:
+		set_bit(channel, drvdata->chs.guaranteed);
+		break;
+
+	case STM_OPTION_INVARIANT:
+		clear_bit(channel, drvdata->chs.guaranteed);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static ssize_t stm_generic_packet(struct stm_data *stm_data,
+				  unsigned int master,
+				  unsigned int channel,
+				  unsigned int packet,
+				  unsigned int flags,
+				  unsigned int size,
+				  const unsigned char *payload)
+{
+	unsigned long ch_addr;
+	struct stm_drvdata *drvdata = container_of(stm_data,
+						   struct stm_drvdata, stm);
+
+	if (!(drvdata && local_read(&drvdata->mode)))
+		return 0;
+
+	if (channel >= drvdata->numsp)
+		return 0;
+
+	ch_addr = (unsigned long)stm_channel_addr(drvdata, channel);
+
+	flags = (flags == STP_PACKET_TIMESTAMPED) ? STM_FLAG_TIMESTAMPED : 0;
+	flags |= test_bit(channel, drvdata->chs.guaranteed) ?
+			   STM_FLAG_GUARANTEED : 0;
+
+	if (size > drvdata->write_bytes)
+		size = drvdata->write_bytes;
+	else
+		size = rounddown_pow_of_two(size);
+
+	switch (packet) {
+	case STP_PACKET_FLAG:
+		ch_addr |= stm_channel_off(STM_PKT_TYPE_FLAG, flags);
+
+		/*
+		 * The generic STM core sets a size of '0' on flag packets.
+		 * As such send a flag packet of size '1' and tell the
+		 * core we did so.
+		 */
+		stm_send((void *)ch_addr, payload, 1, drvdata->write_bytes);
+		size = 1;
+		break;
+
+	case STP_PACKET_DATA:
+		ch_addr |= stm_channel_off(STM_PKT_TYPE_DATA, flags);
+		stm_send((void *)ch_addr, payload, size,
+				drvdata->write_bytes);
+		break;
+
+	default:
+		return -ENOTSUPP;
+	}
+
+	return size;
+}
+
+static ssize_t hwevent_enable_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val = drvdata->stmheer;
+
+	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t hwevent_enable_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t size)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val;
+	int ret = 0;
+
+	ret = kstrtoul(buf, 16, &val);
+	if (ret)
+		return -EINVAL;
+
+	drvdata->stmheer = val;
+	/* HW event enable and trigger go hand in hand */
+	drvdata->stmheter = val;
+
+	return size;
+}
+static DEVICE_ATTR_RW(hwevent_enable);
+
+static ssize_t hwevent_select_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val = drvdata->stmhebsr;
+
+	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t hwevent_select_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t size)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val;
+	int ret = 0;
+
+	ret = kstrtoul(buf, 16, &val);
+	if (ret)
+		return -EINVAL;
+
+	drvdata->stmhebsr = val;
+
+	return size;
+}
+static DEVICE_ATTR_RW(hwevent_select);
+
+static ssize_t port_select_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val;
+
+	if (!local_read(&drvdata->mode)) {
+		val = drvdata->stmspscr;
+	} else {
+		spin_lock(&drvdata->spinlock);
+		val = readl_relaxed(drvdata->base + STMSPSCR);
+		spin_unlock(&drvdata->spinlock);
+	}
+
+	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t port_select_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t size)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val, stmsper;
+	int ret = 0;
+
+	ret = kstrtoul(buf, 16, &val);
+	if (ret)
+		return ret;
+
+	spin_lock(&drvdata->spinlock);
+	drvdata->stmspscr = val;
+
+	if (local_read(&drvdata->mode)) {
+		CS_UNLOCK(drvdata->base);
+		/* Process as per ARM's TRM recommendation */
+		stmsper = readl_relaxed(drvdata->base + STMSPER);
+		writel_relaxed(0x0, drvdata->base + STMSPER);
+		writel_relaxed(drvdata->stmspscr, drvdata->base + STMSPSCR);
+		writel_relaxed(stmsper, drvdata->base + STMSPER);
+		CS_LOCK(drvdata->base);
+	}
+	spin_unlock(&drvdata->spinlock);
+
+	return size;
+}
+static DEVICE_ATTR_RW(port_select);
+
+static ssize_t port_enable_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val;
+
+	if (!local_read(&drvdata->mode)) {
+		val = drvdata->stmsper;
+	} else {
+		spin_lock(&drvdata->spinlock);
+		val = readl_relaxed(drvdata->base + STMSPER);
+		spin_unlock(&drvdata->spinlock);
+	}
+
+	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t port_enable_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t size)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned long val;
+	int ret = 0;
+
+	ret = kstrtoul(buf, 16, &val);
+	if (ret)
+		return ret;
+
+	spin_lock(&drvdata->spinlock);
+	drvdata->stmsper = val;
+
+	if (local_read(&drvdata->mode)) {
+		CS_UNLOCK(drvdata->base);
+		writel_relaxed(drvdata->stmsper, drvdata->base + STMSPER);
+		CS_LOCK(drvdata->base);
+	}
+	spin_unlock(&drvdata->spinlock);
+
+	return size;
+}
+static DEVICE_ATTR_RW(port_enable);
+
+static ssize_t traceid_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	unsigned long val;
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	val = drvdata->traceid;
+	return sprintf(buf, "%#lx\n", val);
+}
+
+static ssize_t traceid_store(struct device *dev,
+			     struct device_attribute *attr,
+			     const char *buf, size_t size)
+{
+	int ret;
+	unsigned long val;
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	ret = kstrtoul(buf, 16, &val);
+	if (ret)
+		return ret;
+
+	/* traceid field is 7bit wide on STM32 */
+	drvdata->traceid = val & 0x7f;
+	return size;
+}
+static DEVICE_ATTR_RW(traceid);
+
+#define coresight_stm_simple_func(name, offset)	\
+	coresight_simple_func(struct stm_drvdata, name, offset)
+
+coresight_stm_simple_func(tcsr, STMTCSR);
+coresight_stm_simple_func(tsfreqr, STMTSFREQR);
+coresight_stm_simple_func(syncr, STMSYNCR);
+coresight_stm_simple_func(sper, STMSPER);
+coresight_stm_simple_func(spter, STMSPTER);
+coresight_stm_simple_func(privmaskr, STMPRIVMASKR);
+coresight_stm_simple_func(spscr, STMSPSCR);
+coresight_stm_simple_func(spmscr, STMSPMSCR);
+coresight_stm_simple_func(spfeat1r, STMSPFEAT1R);
+coresight_stm_simple_func(spfeat2r, STMSPFEAT2R);
+coresight_stm_simple_func(spfeat3r, STMSPFEAT3R);
+coresight_stm_simple_func(devid, CORESIGHT_DEVID);
+
+static struct attribute *coresight_stm_attrs[] = {
+	&dev_attr_hwevent_enable.attr,
+	&dev_attr_hwevent_select.attr,
+	&dev_attr_port_enable.attr,
+	&dev_attr_port_select.attr,
+	&dev_attr_traceid.attr,
+	NULL,
+};
+
+static struct attribute *coresight_stm_mgmt_attrs[] = {
+	&dev_attr_tcsr.attr,
+	&dev_attr_tsfreqr.attr,
+	&dev_attr_syncr.attr,
+	&dev_attr_sper.attr,
+	&dev_attr_spter.attr,
+	&dev_attr_privmaskr.attr,
+	&dev_attr_spscr.attr,
+	&dev_attr_spmscr.attr,
+	&dev_attr_spfeat1r.attr,
+	&dev_attr_spfeat2r.attr,
+	&dev_attr_spfeat3r.attr,
+	&dev_attr_devid.attr,
+	NULL,
+};
+
+static const struct attribute_group coresight_stm_group = {
+	.attrs = coresight_stm_attrs,
+};
+
+static const struct attribute_group coresight_stm_mgmt_group = {
+	.attrs = coresight_stm_mgmt_attrs,
+	.name = "mgmt",
+};
+
+static const struct attribute_group *coresight_stm_groups[] = {
+	&coresight_stm_group,
+	&coresight_stm_mgmt_group,
+	NULL,
+};
+
+static int stm_get_resource_byname(struct device_node *np,
+				   char *ch_base, struct resource *res)
+{
+	const char *name = NULL;
+	int index = 0, found = 0;
+
+	while (!of_property_read_string_index(np, "reg-names", index, &name)) {
+		if (strcmp(ch_base, name)) {
+			index++;
+			continue;
+		}
+
+		/* We have a match and @index is where it's at */
+		found = 1;
+		break;
+	}
+
+	if (!found)
+		return -EINVAL;
+
+	return of_address_to_resource(np, index, res);
+}
+
+static u32 stm_fundamental_data_size(struct stm_drvdata *drvdata)
+{
+	u32 stmspfeat2r;
+
+	if (!IS_ENABLED(CONFIG_64BIT))
+		return 4;
+
+	stmspfeat2r = readl_relaxed(drvdata->base + STMSPFEAT2R);
+
+	/*
+	 * bit[15:12] represents the fundamental data size
+	 * 0 - 32-bit data
+	 * 1 - 64-bit data
+	 */
+	return BMVAL(stmspfeat2r, 12, 15) ? 8 : 4;
+}
+
+static u32 stm_num_stimulus_port(struct stm_drvdata *drvdata)
+{
+	u32 numsp;
+
+	numsp = readl_relaxed(drvdata->base + CORESIGHT_DEVID);
+	/*
+	 * NUMPS in STMDEVID is 17 bit long and if equal to 0x0,
+	 * 32 stimulus ports are supported.
+	 */
+	numsp &= 0x1ffff;
+	if (!numsp)
+		numsp = STM_32_CHANNEL;
+	return numsp;
+}
+
+static void stm_init_default_data(struct stm_drvdata *drvdata)
+{
+	/* Don't use port selection */
+	drvdata->stmspscr = 0x0;
+	/*
+	 * Enable all channel regardless of their number.  When port
+	 * selection isn't used (see above) STMSPER applies to all
+	 * 32 channel group available, hence setting all 32 bits to 1
+	 */
+	drvdata->stmsper = ~0x0;
+
+	/*
+	 * The trace ID value for *ETM* tracers start at CPU_ID * 2 + 0x10 and
+	 * anything equal to or higher than 0x70 is reserved.  Since 0x00 is
+	 * also reserved the STM trace ID needs to be higher than 0x00 and
+	 * lowner than 0x10.
+	 */
+	drvdata->traceid = 0x1;
+
+	/* Set invariant transaction timing on all channels */
+	bitmap_clear(drvdata->chs.guaranteed, 0, drvdata->numsp);
+}
+
+static void stm_init_generic_data(struct stm_drvdata *drvdata)
+{
+	drvdata->stm.name = dev_name(drvdata->dev);
+
+	/*
+	 * MasterIDs are assigned at HW design phase. As such the core is
+	 * using a single master for interaction with this device.
+	 */
+	drvdata->stm.sw_start = 1;
+	drvdata->stm.sw_end = 1;
+	drvdata->stm.hw_override = true;
+	drvdata->stm.sw_nchannels = drvdata->numsp;
+	drvdata->stm.packet = stm_generic_packet;
+	drvdata->stm.link = stm_generic_link;
+	drvdata->stm.unlink = stm_generic_unlink;
+	drvdata->stm.set_options = stm_generic_set_options;
+}
+
+static int stm_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret;
+	void __iomem *base;
+	unsigned long *guaranteed;
+	struct device *dev = &adev->dev;
+	struct coresight_platform_data *pdata = NULL;
+	struct stm_drvdata *drvdata;
+	struct resource *res = &adev->res;
+	struct resource ch_res;
+	size_t res_size, bitmap_size;
+	struct coresight_desc *desc;
+	struct device_node *np = adev->dev.of_node;
+
+	if (np) {
+		pdata = of_get_coresight_platform_data(dev, np);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
+		adev->dev.platform_data = pdata;
+	}
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->dev = &adev->dev;
+	drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */
+	if (!IS_ERR(drvdata->atclk)) {
+		ret = clk_prepare_enable(drvdata->atclk);
+		if (ret)
+			return ret;
+	}
+	dev_set_drvdata(dev, drvdata);
+
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+	drvdata->base = base;
+
+	ret = stm_get_resource_byname(np, "stm-stimulus-base", &ch_res);
+	if (ret)
+		return ret;
+
+	base = devm_ioremap_resource(dev, &ch_res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+	drvdata->chs.base = base;
+
+	drvdata->write_bytes = stm_fundamental_data_size(drvdata);
+
+	if (boot_nr_channel) {
+		drvdata->numsp = boot_nr_channel;
+		res_size = min((resource_size_t)(boot_nr_channel *
+				  BYTES_PER_CHANNEL), resource_size(res));
+	} else {
+		drvdata->numsp = stm_num_stimulus_port(drvdata);
+		res_size = min((resource_size_t)(drvdata->numsp *
+				 BYTES_PER_CHANNEL), resource_size(res));
+	}
+	bitmap_size = BITS_TO_LONGS(drvdata->numsp) * sizeof(long);
+
+	guaranteed = devm_kzalloc(dev, bitmap_size, GFP_KERNEL);
+	if (!guaranteed)
+		return -ENOMEM;
+	drvdata->chs.guaranteed = guaranteed;
+
+	spin_lock_init(&drvdata->spinlock);
+
+	stm_init_default_data(drvdata);
+	stm_init_generic_data(drvdata);
+
+	if (stm_register_device(dev, &drvdata->stm, THIS_MODULE)) {
+		dev_info(dev,
+			 "stm_register_device failed, probing deffered\n");
+		return -EPROBE_DEFER;
+	}
+
+	desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
+	if (!desc) {
+		ret = -ENOMEM;
+		goto stm_unregister;
+	}
+
+	desc->type = CORESIGHT_DEV_TYPE_SOURCE;
+	desc->subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE;
+	desc->ops = &stm_cs_ops;
+	desc->pdata = pdata;
+	desc->dev = dev;
+	desc->groups = coresight_stm_groups;
+	drvdata->csdev = coresight_register(desc);
+	if (IS_ERR(drvdata->csdev)) {
+		ret = PTR_ERR(drvdata->csdev);
+		goto stm_unregister;
+	}
+
+	pm_runtime_put(&adev->dev);
+
+	dev_info(dev, "%s initialized\n", (char *)id->data);
+	return 0;
+
+stm_unregister:
+	stm_unregister_device(&drvdata->stm);
+	return ret;
+}
+
+#ifdef CONFIG_PM
+static int stm_runtime_suspend(struct device *dev)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata && !IS_ERR(drvdata->atclk))
+		clk_disable_unprepare(drvdata->atclk);
+
+	return 0;
+}
+
+static int stm_runtime_resume(struct device *dev)
+{
+	struct stm_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata && !IS_ERR(drvdata->atclk))
+		clk_prepare_enable(drvdata->atclk);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops stm_dev_pm_ops = {
+	SET_RUNTIME_PM_OPS(stm_runtime_suspend, stm_runtime_resume, NULL)
+};
+
+static struct amba_id stm_ids[] = {
+	{
+		.id     = 0x0003b962,
+		.mask   = 0x0003ffff,
+		.data	= "STM32",
+	},
+	{ 0, 0},
+};
+
+static struct amba_driver stm_driver = {
+	.drv = {
+		.name   = "coresight-stm",
+		.owner	= THIS_MODULE,
+		.pm	= &stm_dev_pm_ops,
+		.suppress_bind_attrs = true,
+	},
+	.probe          = stm_probe,
+	.id_table	= stm_ids,
+};
+
+builtin_amba_driver(stm_driver);
diff --git a/include/linux/coresight-stm.h b/include/linux/coresight-stm.h
new file mode 100644
index 0000000..a978bb8
--- /dev/null
+++ b/include/linux/coresight-stm.h
@@ -0,0 +1,6 @@
+#ifndef __LINUX_CORESIGHT_STM_H_
+#define __LINUX_CORESIGHT_STM_H_
+
+#include <uapi/linux/coresight-stm.h>
+
+#endif
diff --git a/include/uapi/linux/coresight-stm.h b/include/uapi/linux/coresight-stm.h
new file mode 100644
index 0000000..7e4272c
--- /dev/null
+++ b/include/uapi/linux/coresight-stm.h
@@ -0,0 +1,21 @@
+#ifndef __UAPI_CORESIGHT_STM_H_
+#define __UAPI_CORESIGHT_STM_H_
+
+#define STM_FLAG_TIMESTAMPED   BIT(3)
+#define STM_FLAG_GUARANTEED    BIT(7)
+
+/*
+ * The CoreSight STM supports guaranteed and invariant timing
+ * transactions.  Guaranteed transactions are guaranteed to be
+ * traced, this might involve stalling the bus or system to
+ * ensure the transaction is accepted by the STM.  While invariant
+ * timing transactions are not guaranteed to be traced, they
+ * will take an invariant amount of time regardless of the
+ * state of the STM.
+ */
+enum {
+	STM_OPTION_GUARANTEED = 0,
+	STM_OPTION_INVARIANT,
+};
+
+#endif
