Merge tag 'stm-intel_th-for-greg-20180329' of git://git.kernel.org/pub/scm/linux/kernel/git/ash/stm into char-misc-next

Alexander writes:

stm class/intel_th: Updates for 4.17

These are:
  * Mass conversion to GPL-2 SPDX header
  * Moved "hwtracing" to now its own submenu, to uncrowd the parent menu a bit
  * Added MAINTAINERS entry for drivers/hwtracing
  * Somewhat small Trace Hub fixes
  * Added ACPI glue layer for the Trace Hub
  * Added more module parameters to dummy_stm for better test coverage

23 files changed, 161 insertions, 179 deletions

diff --git a/drivers/hwtracing/Kconfig b/drivers/hwtracing/Kconfig
new file mode 100644
index 0000000..f68e025
--- /dev/null
+++ b/drivers/hwtracing/Kconfig
@@ -0,0 +1,7 @@
+menu "HW tracing support"
+
+source "drivers/hwtracing/stm/Kconfig"
+
+source "drivers/hwtracing/intel_th/Kconfig"
+
+endmenu
diff --git a/drivers/hwtracing/intel_th/Kconfig b/drivers/hwtracing/intel_th/Kconfig
index 1b412f8..ca0527d 100644
--- a/drivers/hwtracing/intel_th/Kconfig
+++ b/drivers/hwtracing/intel_th/Kconfig
@@ -25,6 +25,18 @@ config INTEL_TH_PCI
 
 	  Say Y here to enable PCI Intel TH support.
 
+config INTEL_TH_ACPI
+	tristate "Intel(R) Trace Hub ACPI controller"
+	depends on ACPI
+	help
+	  Intel(R) Trace Hub may exist as an ACPI device. This option enables
+	  support glue layer for ACPI-based Intel TH. This typically implies
+	  'host debugger' mode, that is, the trace configuration and capture
+	  is handled by an external debug host and corresponding controls will
+	  not be available on the target.
+
+	  Say Y here to enable ACPI Intel TH support.
+
 config INTEL_TH_GTH
 	tristate "Intel(R) Trace Hub Global Trace Hub"
 	help
diff --git a/drivers/hwtracing/intel_th/Makefile b/drivers/hwtracing/intel_th/Makefile
index 880c9b5..d9252fa 100644
--- a/drivers/hwtracing/intel_th/Makefile
+++ b/drivers/hwtracing/intel_th/Makefile
@@ -6,6 +6,9 @@ intel_th-$(CONFIG_INTEL_TH_DEBUG) += debug.o
 obj-$(CONFIG_INTEL_TH_PCI)	+= intel_th_pci.o
 intel_th_pci-y			:= pci.o
 
+obj-$(CONFIG_INTEL_TH_ACPI)	+= intel_th_acpi.o
+intel_th_acpi-y			:= acpi.o
+
 obj-$(CONFIG_INTEL_TH_GTH)	+= intel_th_gth.o
 intel_th_gth-y			:= gth.o
 
diff --git a/drivers/hwtracing/intel_th/acpi.c b/drivers/hwtracing/intel_th/acpi.c
new file mode 100644
index 0000000..87bc374
--- /dev/null
+++ b/drivers/hwtracing/intel_th/acpi.c
@@ -0,0 +1,79 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Intel(R) Trace Hub ACPI driver
+ *
+ * Copyright (C) 2017 Intel Corporation.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+
+#include "intel_th.h"
+
+#define DRIVER_NAME "intel_th_acpi"
+
+static const struct intel_th_drvdata intel_th_acpi_pch = {
+	.host_mode_only	= 1,
+};
+
+static const struct intel_th_drvdata intel_th_acpi_uncore = {
+	.host_mode_only	= 1,
+};
+
+static const struct acpi_device_id intel_th_acpi_ids[] = {
+	{ "INTC1000",	(kernel_ulong_t)&intel_th_acpi_uncore },
+	{ "INTC1001",	(kernel_ulong_t)&intel_th_acpi_pch },
+	{ "",		0 },
+};
+
+MODULE_DEVICE_TABLE(acpi, intel_th_acpi_ids);
+
+static int intel_th_acpi_probe(struct platform_device *pdev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	const struct acpi_device_id *id;
+	struct intel_th *th;
+
+	id = acpi_match_device(intel_th_acpi_ids, &pdev->dev);
+	if (!id)
+		return -ENODEV;
+
+	th = intel_th_alloc(&pdev->dev, (void *)id->driver_data,
+			    pdev->resource, pdev->num_resources, -1);
+	if (IS_ERR(th))
+		return PTR_ERR(th);
+
+	adev->driver_data = th;
+
+	return 0;
+}
+
+static int intel_th_acpi_remove(struct platform_device *pdev)
+{
+	struct intel_th *th = platform_get_drvdata(pdev);
+
+	intel_th_free(th);
+
+	return 0;
+}
+
+static struct platform_driver intel_th_acpi_driver = {
+	.probe		= intel_th_acpi_probe,
+	.remove		= intel_th_acpi_remove,
+	.driver		= {
+		.name			= DRIVER_NAME,
+		.acpi_match_table	= intel_th_acpi_ids,
+	},
+};
+
+module_platform_driver(intel_th_acpi_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel(R) Trace Hub ACPI controller driver");
+MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@intel.com>");
diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 1a023e3..da962aa 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub driver core
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
@@ -638,7 +630,8 @@ intel_th_subdevice_alloc(struct intel_th *th,
 		thdev->output.port = -1;
 		thdev->output.scratchpad = subdev->scrpd;
 	} else if (subdev->type == INTEL_TH_SWITCH) {
-		thdev->host_mode = host_mode;
+		thdev->host_mode =
+			INTEL_TH_CAP(th, host_mode_only) ? true : host_mode;
 		th->hub = thdev;
 	}
 
@@ -737,7 +730,8 @@ static int intel_th_populate(struct intel_th *th)
 		struct intel_th_device *thdev;
 
 		/* only allow SOURCE and SWITCH devices in host mode */
-		if (host_mode && subdev->type == INTEL_TH_OUTPUT)
+		if ((INTEL_TH_CAP(th, host_mode_only) || host_mode) &&
+		    subdev->type == INTEL_TH_OUTPUT)
 			continue;
 
 		/*
@@ -813,7 +807,14 @@ intel_th_alloc(struct device *dev, struct intel_th_drvdata *drvdata,
 	       struct resource *devres, unsigned int ndevres, int irq)
 {
 	struct intel_th *th;
-	int err;
+	int err, r;
+
+	if (irq == -1)
+		for (r = 0; r < ndevres; r++)
+			if (devres[r].flags & IORESOURCE_IRQ) {
+				irq = devres[r].start;
+				break;
+			}
 
 	th = kzalloc(sizeof(*th), GFP_KERNEL);
 	if (!th)
@@ -935,9 +936,13 @@ EXPORT_SYMBOL_GPL(intel_th_trace_disable);
 int intel_th_set_output(struct intel_th_device *thdev,
 			unsigned int master)
 {
-	struct intel_th_device *hub = to_intel_th_device(thdev->dev.parent);
+	struct intel_th_device *hub = to_intel_th_hub(thdev);
 	struct intel_th_driver *hubdrv = to_intel_th_driver(hub->dev.driver);
 
+	/* In host mode, this is up to the external debugger, do nothing. */
+	if (hub->host_mode)
+		return 0;
+
 	if (!hubdrv->set_output)
 		return -ENOTSUPP;
 
diff --git a/drivers/hwtracing/intel_th/debug.c b/drivers/hwtracing/intel_th/debug.c
index 788a1f0..ff79063 100644
--- a/drivers/hwtracing/intel_th/debug.c
+++ b/drivers/hwtracing/intel_th/debug.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub driver debugging
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #include <linux/types.h>
diff --git a/drivers/hwtracing/intel_th/debug.h b/drivers/hwtracing/intel_th/debug.h
index 88311ba..78bd7e4 100644
--- a/drivers/hwtracing/intel_th/debug.h
+++ b/drivers/hwtracing/intel_th/debug.h
@@ -1,16 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Intel(R) Trace Hub driver debugging
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #ifndef __INTEL_TH_DEBUG_H__
diff --git a/drivers/hwtracing/intel_th/gth.c b/drivers/hwtracing/intel_th/gth.c
index 018678e..8426b79 100644
--- a/drivers/hwtracing/intel_th/gth.c
+++ b/drivers/hwtracing/intel_th/gth.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub Global Trace Hub
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
diff --git a/drivers/hwtracing/intel_th/gth.h b/drivers/hwtracing/intel_th/gth.h
index f3d2342..6f2b0b9 100644
--- a/drivers/hwtracing/intel_th/gth.h
+++ b/drivers/hwtracing/intel_th/gth.h
@@ -1,16 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Intel(R) Trace Hub Global Trace Hub (GTH) data structures
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #ifndef __INTEL_TH_GTH_H__
diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h
index 99ad563..780206d 100644
--- a/drivers/hwtracing/intel_th/intel_th.h
+++ b/drivers/hwtracing/intel_th/intel_th.h
@@ -1,16 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Intel(R) Trace Hub data structures
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #ifndef __INTEL_TH_H__
@@ -50,9 +42,11 @@ struct intel_th_output {
 /**
  * struct intel_th_drvdata - describes hardware capabilities and quirks
  * @tscu_enable:	device needs SW to enable time stamping unit
+ * @host_mode_only:	device can only operate in 'host debugger' mode
  */
 struct intel_th_drvdata {
-	unsigned int	tscu_enable        : 1;
+	unsigned int	tscu_enable        : 1,
+			host_mode_only     : 1;
 };
 
 #define INTEL_TH_CAP(_th, _cap) ((_th)->drvdata ? (_th)->drvdata->_cap : 0)
diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index dfb57ea..ede3883 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub Memory Storage Unit
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
diff --git a/drivers/hwtracing/intel_th/msu.h b/drivers/hwtracing/intel_th/msu.h
index 9b710e4..9cc8ace 100644
--- a/drivers/hwtracing/intel_th/msu.h
+++ b/drivers/hwtracing/intel_th/msu.h
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub Memory Storage Unit (MSU) data structures
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #ifndef __INTEL_TH_MSU_H__
diff --git a/drivers/hwtracing/intel_th/pci.c b/drivers/hwtracing/intel_th/pci.c
index c2a2ce8..c2e55e5 100644
--- a/drivers/hwtracing/intel_th/pci.c
+++ b/drivers/hwtracing/intel_th/pci.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub pci driver
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
diff --git a/drivers/hwtracing/intel_th/pti.c b/drivers/hwtracing/intel_th/pti.c
index e96a1fc..5669433 100644
--- a/drivers/hwtracing/intel_th/pti.c
+++ b/drivers/hwtracing/intel_th/pti.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub PTI output driver
  *
  * Copyright (C) 2014-2016 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
diff --git a/drivers/hwtracing/intel_th/pti.h b/drivers/hwtracing/intel_th/pti.h
index 30827be..e9381ba 100644
--- a/drivers/hwtracing/intel_th/pti.h
+++ b/drivers/hwtracing/intel_th/pti.h
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub PTI output data structures
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #ifndef __INTEL_TH_STH_H__
diff --git a/drivers/hwtracing/intel_th/sth.c b/drivers/hwtracing/intel_th/sth.c
index b034446..4b7ae47 100644
--- a/drivers/hwtracing/intel_th/sth.c
+++ b/drivers/hwtracing/intel_th/sth.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Intel(R) Trace Hub Software Trace Hub support
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
diff --git a/drivers/hwtracing/intel_th/sth.h b/drivers/hwtracing/intel_th/sth.h
index f1390cd..f97fc0c 100644
--- a/drivers/hwtracing/intel_th/sth.h
+++ b/drivers/hwtracing/intel_th/sth.h
@@ -1,16 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Intel(R) Trace Hub Software Trace Hub (STH) data structures
  *
  * Copyright (C) 2014-2015 Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
  */
 
 #ifndef __INTEL_TH_STH_H__
diff --git a/drivers/hwtracing/stm/console.c b/drivers/hwtracing/stm/console.c
index c9d9a8d..a00f65e 100644
--- a/drivers/hwtracing/stm/console.c
+++ b/drivers/hwtracing/stm/console.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Simple kernel console driver for STM devices
  * Copyright (c) 2014, Intel Corporation.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
- *
  * STM console will send kernel messages over STM devices to a trace host.
  */
 
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index f129869..05386b7 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * System Trace Module (STM) infrastructure
  * Copyright (c) 2014, Intel Corporation.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
- *
  * STM class implements generic infrastructure for  System Trace Module devices
  * as defined in MIPI STPv2 specification.
  */
diff --git a/drivers/hwtracing/stm/dummy_stm.c b/drivers/hwtracing/stm/dummy_stm.c
index c5f94ca..38528ff 100644
--- a/drivers/hwtracing/stm/dummy_stm.c
+++ b/drivers/hwtracing/stm/dummy_stm.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * A dummy STM device for stm/stm_source class testing.
  * Copyright (c) 2014, Intel Corporation.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
- *
  * STM class implements generic infrastructure for  System Trace Module devices
  * as defined in MIPI STPv2 specification.
  */
@@ -20,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/stm.h>
+#include <uapi/linux/stm.h>
 
 static ssize_t notrace
 dummy_stm_packet(struct stm_data *stm_data, unsigned int master,
@@ -52,6 +45,18 @@ static unsigned int fail_mode;
 
 module_param(fail_mode, int, 0600);
 
+static unsigned int master_min;
+
+module_param(master_min, int, 0400);
+
+static unsigned int master_max = STP_MASTER_MAX;
+
+module_param(master_max, int, 0400);
+
+static unsigned int nr_channels = STP_CHANNEL_MAX;
+
+module_param(nr_channels, int, 0400);
+
 static int dummy_stm_link(struct stm_data *data, unsigned int master,
 			  unsigned int channel)
 {
@@ -68,14 +73,19 @@ static int dummy_stm_init(void)
 	if (nr_dummies < 0 || nr_dummies > DUMMY_STM_MAX)
 		return -EINVAL;
 
+	if (master_min > master_max ||
+	    master_max > STP_MASTER_MAX ||
+	    nr_channels > STP_CHANNEL_MAX)
+		return -EINVAL;
+
 	for (i = 0; i < nr_dummies; i++) {
 		dummy_stm[i].name = kasprintf(GFP_KERNEL, "dummy_stm.%d", i);
 		if (!dummy_stm[i].name)
 			goto fail_unregister;
 
-		dummy_stm[i].sw_start		= 0x0000;
-		dummy_stm[i].sw_end		= 0xffff;
-		dummy_stm[i].sw_nchannels	= 0xffff;
+		dummy_stm[i].sw_start		= master_min;
+		dummy_stm[i].sw_end		= master_max;
+		dummy_stm[i].sw_nchannels	= nr_channels;
 		dummy_stm[i].packet		= dummy_stm_packet;
 		dummy_stm[i].link		= dummy_stm_link;
 
diff --git a/drivers/hwtracing/stm/heartbeat.c b/drivers/hwtracing/stm/heartbeat.c
index 3da7b67..7db4239 100644
--- a/drivers/hwtracing/stm/heartbeat.c
+++ b/drivers/hwtracing/stm/heartbeat.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Simple heartbeat STM source driver
  * Copyright (c) 2016, Intel Corporation.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
- *
  * Heartbeat STM source will send repetitive messages over STM devices to a
  * trace host.
  */
diff --git a/drivers/hwtracing/stm/policy.c b/drivers/hwtracing/stm/policy.c
index 33e9a1b..3fd07e2 100644
--- a/drivers/hwtracing/stm/policy.c
+++ b/drivers/hwtracing/stm/policy.c
@@ -1,16 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * System Trace Module (STM) master/channel allocation policy management
  * Copyright (c) 2014, Intel Corporation.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
- *
  * A master/channel allocation policy allows mapping string identifiers to
  * master and channel ranges, where allocation can be done.
  */
diff --git a/drivers/hwtracing/stm/stm.h b/drivers/hwtracing/stm/stm.h
index 4e8c6926..923571a 100644
--- a/drivers/hwtracing/stm/stm.h
+++ b/drivers/hwtracing/stm/stm.h
@@ -1,16 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * System Trace Module (STM) infrastructure
  * Copyright (c) 2014, Intel Corporation.
  *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.
- *
  * STM class implements generic infrastructure for  System Trace Module devices
  * as defined in MIPI STPv2 specification.
  */