License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

38 files changed, 38 insertions, 0 deletions

diff --git a/drivers/isdn/Makefile b/drivers/isdn/Makefile
index c32e45826c2c3..e7d3d8f2ad5a5 100644
--- a/drivers/isdn/Makefile
+++ b/drivers/isdn/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # Makefile for the kernel ISDN subsystem and device drivers.
 
 # Object files in subdirectories
diff --git a/drivers/isdn/capi/Makefile b/drivers/isdn/capi/Makefile
index 4d5b4b71db1e4..06da3ed2c40ab 100644
--- a/drivers/isdn/capi/Makefile
+++ b/drivers/isdn/capi/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # Makefile for the CAPI subsystem.
 
 # Ordering constraints: kernelcapi.o first
diff --git a/drivers/isdn/capi/capilib.c b/drivers/isdn/capi/capilib.c
index 33361f833c01f..a39ad3796bba1 100644
--- a/drivers/isdn/capi/capilib.c
+++ b/drivers/isdn/capi/capilib.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 
 #include <linux/slab.h>
 #include <linux/kernel.h>
diff --git a/drivers/isdn/gigaset/Makefile b/drivers/isdn/gigaset/Makefile
index c453b72272a09..ac45a2739f562 100644
--- a/drivers/isdn/gigaset/Makefile
+++ b/drivers/isdn/gigaset/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 gigaset-y := common.o interface.o proc.o ev-layer.o asyncdata.o
 gigaset-$(CONFIG_GIGASET_CAPI) += capi.o
 gigaset-$(CONFIG_GIGASET_I4L) += i4l.o
diff --git a/drivers/isdn/hardware/avm/Makefile b/drivers/isdn/hardware/avm/Makefile
index b540e8f2efb62..3830a0573fcc6 100644
--- a/drivers/isdn/hardware/avm/Makefile
+++ b/drivers/isdn/hardware/avm/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # Makefile for the AVM ISDN device drivers
 
 # Each configuration option enables a list of files.
diff --git a/drivers/isdn/hardware/eicon/Makefile b/drivers/isdn/hardware/eicon/Makefile
index 4fa7fdb7df0d7..a0ab2e2d7df0d 100644
--- a/drivers/isdn/hardware/eicon/Makefile
+++ b/drivers/isdn/hardware/eicon/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # Makefile for the Eicon DIVA ISDN drivers.
 
 # Each configuration option enables a list of files.
diff --git a/drivers/isdn/hardware/eicon/adapter.h b/drivers/isdn/hardware/eicon/adapter.h
index 71a7c2f084a73..f9b24eb8781df 100644
--- a/drivers/isdn/hardware/eicon/adapter.h
+++ b/drivers/isdn/hardware/eicon/adapter.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: adapter.h,v 1.4 2004/03/21 17:26:01 armin Exp $ */
 
 #ifndef __DIVA_USER_MODE_IDI_ADAPTER_H__
diff --git a/drivers/isdn/hardware/eicon/debug.c b/drivers/isdn/hardware/eicon/debug.c
index 8bc2791bc39c1..301788115c4f5 100644
--- a/drivers/isdn/hardware/eicon/debug.c
+++ b/drivers/isdn/hardware/eicon/debug.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 #include "platform.h"
 #include "pc.h"
 #include "di_defs.h"
diff --git a/drivers/isdn/hardware/eicon/diva.c b/drivers/isdn/hardware/eicon/diva.c
index d91dd580e9781..944a7f3380991 100644
--- a/drivers/isdn/hardware/eicon/diva.c
+++ b/drivers/isdn/hardware/eicon/diva.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* $Id: diva.c,v 1.21.4.1 2004/05/08 14:33:43 armin Exp $ */
 
 #define CARDTYPE_H_WANT_DATA            1
diff --git a/drivers/isdn/hardware/eicon/diva.h b/drivers/isdn/hardware/eicon/diva.h
index e979085d1b891..b067032093a8a 100644
--- a/drivers/isdn/hardware/eicon/diva.h
+++ b/drivers/isdn/hardware/eicon/diva.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: diva.h,v 1.1.2.2 2001/02/08 12:25:43 armin Exp $ */
 
 #ifndef __DIVA_XDI_OS_PART_H__
diff --git a/drivers/isdn/hardware/eicon/diva_pci.h b/drivers/isdn/hardware/eicon/diva_pci.h
index bb4b562050f6a..7ef5db98ad3c7 100644
--- a/drivers/isdn/hardware/eicon/diva_pci.h
+++ b/drivers/isdn/hardware/eicon/diva_pci.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: diva_pci.h,v 1.6 2003/01/04 15:29:45 schindler Exp $ */
 
 #ifndef __DIVA_PCI_INTERFACE_H__
diff --git a/drivers/isdn/hardware/eicon/dqueue.h b/drivers/isdn/hardware/eicon/dqueue.h
index 6992c45457a4e..2da9799686abe 100644
--- a/drivers/isdn/hardware/eicon/dqueue.h
+++ b/drivers/isdn/hardware/eicon/dqueue.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: dqueue.h,v 1.1.2.2 2001/02/08 12:25:43 armin Exp $ */
 
 #ifndef _DIVA_USER_MODE_IDI_DATA_QUEUE_H__
diff --git a/drivers/isdn/hardware/eicon/dsp_tst.h b/drivers/isdn/hardware/eicon/dsp_tst.h
index fe36f138be8b8..85edd3ea50f7d 100644
--- a/drivers/isdn/hardware/eicon/dsp_tst.h
+++ b/drivers/isdn/hardware/eicon/dsp_tst.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: dsp_tst.h,v 1.1.2.2 2001/02/08 12:25:43 armin Exp $ */
 
 #ifndef __DIVA_PRI_HOST_TEST_DSPS_H__
diff --git a/drivers/isdn/hardware/eicon/entity.h b/drivers/isdn/hardware/eicon/entity.h
index fdb83416af31c..f9767d321db9e 100644
--- a/drivers/isdn/hardware/eicon/entity.h
+++ b/drivers/isdn/hardware/eicon/entity.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: entity.h,v 1.4 2004/03/21 17:26:01 armin Exp $ */
 
 #ifndef __DIVAS_USER_MODE_IDI_ENTITY__
diff --git a/drivers/isdn/hardware/eicon/os_4bri.c b/drivers/isdn/hardware/eicon/os_4bri.c
index 1891246807edf..87db5f4df27d0 100644
--- a/drivers/isdn/hardware/eicon/os_4bri.c
+++ b/drivers/isdn/hardware/eicon/os_4bri.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* $Id: os_4bri.c,v 1.28.4.4 2005/02/11 19:40:25 armin Exp $ */
 
 #include "platform.h"
diff --git a/drivers/isdn/hardware/eicon/os_4bri.h b/drivers/isdn/hardware/eicon/os_4bri.h
index 72253278d4f5c..94b2709537d83 100644
--- a/drivers/isdn/hardware/eicon/os_4bri.h
+++ b/drivers/isdn/hardware/eicon/os_4bri.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: os_4bri.h,v 1.1.2.2 2001/02/08 12:25:44 armin Exp $ */
 
 #ifndef __DIVA_OS_4_BRI_H__
diff --git a/drivers/isdn/hardware/eicon/os_bri.c b/drivers/isdn/hardware/eicon/os_bri.c
index 20f2653c58fad..de93090bcacb1 100644
--- a/drivers/isdn/hardware/eicon/os_bri.c
+++ b/drivers/isdn/hardware/eicon/os_bri.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* $Id: os_bri.c,v 1.21 2004/03/21 17:26:01 armin Exp $ */
 
 #include "platform.h"
diff --git a/drivers/isdn/hardware/eicon/os_bri.h b/drivers/isdn/hardware/eicon/os_bri.h
index 02e7456f89621..37c92cc53dedc 100644
--- a/drivers/isdn/hardware/eicon/os_bri.h
+++ b/drivers/isdn/hardware/eicon/os_bri.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: os_bri.h,v 1.1.2.2 2001/02/08 12:25:44 armin Exp $ */
 
 #ifndef __DIVA_OS_BRI_REV_1_H__
diff --git a/drivers/isdn/hardware/eicon/os_pri.c b/drivers/isdn/hardware/eicon/os_pri.c
index da4957abb4222..b20f1fb89d14a 100644
--- a/drivers/isdn/hardware/eicon/os_pri.c
+++ b/drivers/isdn/hardware/eicon/os_pri.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* $Id: os_pri.c,v 1.32 2004/03/21 17:26:01 armin Exp $ */
 
 #include "platform.h"
diff --git a/drivers/isdn/hardware/eicon/os_pri.h b/drivers/isdn/hardware/eicon/os_pri.h
index 537c74d042e71..0e91855b171a6 100644
--- a/drivers/isdn/hardware/eicon/os_pri.h
+++ b/drivers/isdn/hardware/eicon/os_pri.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: os_pri.h,v 1.1.2.2 2001/02/08 12:25:44 armin Exp $ */
 
 #ifndef __DIVA_OS_PRI_REV_1_H__
diff --git a/drivers/isdn/hardware/eicon/um_idi.c b/drivers/isdn/hardware/eicon/um_idi.c
index e1519718ce67e..db4dd4ff3642d 100644
--- a/drivers/isdn/hardware/eicon/um_idi.c
+++ b/drivers/isdn/hardware/eicon/um_idi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /* $Id: um_idi.c,v 1.14 2004/03/21 17:54:37 armin Exp $ */
 
 #include "platform.h"
diff --git a/drivers/isdn/hardware/eicon/um_idi.h b/drivers/isdn/hardware/eicon/um_idi.h
index ffb88f7b42fc5..9aedd9e351a39 100644
--- a/drivers/isdn/hardware/eicon/um_idi.h
+++ b/drivers/isdn/hardware/eicon/um_idi.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: um_idi.h,v 1.6 2004/03/21 17:26:01 armin Exp $ */
 
 #ifndef __DIVA_USER_MODE_IDI_CORE_H__
diff --git a/drivers/isdn/hardware/eicon/um_xdi.h b/drivers/isdn/hardware/eicon/um_xdi.h
index b48fc042a5bc4..1f37aa4efd18d 100644
--- a/drivers/isdn/hardware/eicon/um_xdi.h
+++ b/drivers/isdn/hardware/eicon/um_xdi.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: um_xdi.h,v 1.1.2.2 2002/10/02 14:38:38 armin Exp $ */
 
 #ifndef __DIVA_USER_MODE_XDI_H__
diff --git a/drivers/isdn/hardware/eicon/xdi_adapter.h b/drivers/isdn/hardware/eicon/xdi_adapter.h
index d303e65dbe6ce..b036e217c6595 100644
--- a/drivers/isdn/hardware/eicon/xdi_adapter.h
+++ b/drivers/isdn/hardware/eicon/xdi_adapter.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: xdi_adapter.h,v 1.7 2004/03/21 17:26:01 armin Exp $ */
 
 #ifndef __DIVA_OS_XDI_ADAPTER_H__
diff --git a/drivers/isdn/hardware/eicon/xdi_msg.h b/drivers/isdn/hardware/eicon/xdi_msg.h
index 2498c349a32e4..0646079bf466b 100644
--- a/drivers/isdn/hardware/eicon/xdi_msg.h
+++ b/drivers/isdn/hardware/eicon/xdi_msg.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /* $Id: xdi_msg.h,v 1.1.2.2 2001/02/16 08:40:36 armin Exp $ */
 
 #ifndef __DIVA_XDI_UM_CFG_MESSAGE_H__
diff --git a/drivers/isdn/hardware/mISDN/Makefile b/drivers/isdn/hardware/mISDN/Makefile
index 2987d990993f6..422f9fd8ab9a4 100644
--- a/drivers/isdn/hardware/mISDN/Makefile
+++ b/drivers/isdn/hardware/mISDN/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the modular ISDN hardware drivers
 #
diff --git a/drivers/isdn/hardware/mISDN/hfc_multi.h b/drivers/isdn/hardware/mISDN/hfc_multi.h
index c601f880141e6..5acf826d913cd 100644
--- a/drivers/isdn/hardware/mISDN/hfc_multi.h
+++ b/drivers/isdn/hardware/mISDN/hfc_multi.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * see notice in hfc_multi.c
  */
diff --git a/drivers/isdn/hardware/mISDN/hfc_multi_8xx.h b/drivers/isdn/hardware/mISDN/hfc_multi_8xx.h
index 8a254747768e9..b0d772340e163 100644
--- a/drivers/isdn/hardware/mISDN/hfc_multi_8xx.h
+++ b/drivers/isdn/hardware/mISDN/hfc_multi_8xx.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * For License see notice in hfc_multi.c
  *
diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.h b/drivers/isdn/hardware/mISDN/hfcsusb.h
index 5f8f1d9cac11a..e4fa2a2824af0 100644
--- a/drivers/isdn/hardware/mISDN/hfcsusb.h
+++ b/drivers/isdn/hardware/mISDN/hfcsusb.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * hfcsusb.h, HFC-S USB mISDN driver
  */
diff --git a/drivers/isdn/hisax/Makefile b/drivers/isdn/hisax/Makefile
index 646368fe41c94..3eca9d23f1c2f 100644
--- a/drivers/isdn/hisax/Makefile
+++ b/drivers/isdn/hisax/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # Makefile for the hisax ISDN device driver
 
 # The target object and module list name.
diff --git a/drivers/isdn/hisax/hfc4s8s_l1.h b/drivers/isdn/hisax/hfc4s8s_l1.h
index 6a8f89113d2f2..4665b9d5df163 100644
--- a/drivers/isdn/hisax/hfc4s8s_l1.h
+++ b/drivers/isdn/hisax/hfc4s8s_l1.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /***************************************************************/
 /*  $Id: hfc4s8s_l1.h,v 1.1 2005/02/02 17:28:55 martinb1 Exp $ */
 /*                                                             */
diff --git a/drivers/isdn/hisax/hfc_usb.h b/drivers/isdn/hisax/hfc_usb.h
index f987bf89da1a7..9a212330e8a81 100644
--- a/drivers/isdn/hisax/hfc_usb.h
+++ b/drivers/isdn/hisax/hfc_usb.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * hfc_usb.h
  *
diff --git a/drivers/isdn/hisax/hisax_fcpcipnp.h b/drivers/isdn/hisax/hisax_fcpcipnp.h
index aedef97827fe5..1f64e9937aa13 100644
--- a/drivers/isdn/hisax/hisax_fcpcipnp.h
+++ b/drivers/isdn/hisax/hisax_fcpcipnp.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include "hisax_if.h"
 #include "hisax_isac.h"
 #include <linux/pci.h>
diff --git a/drivers/isdn/hisax/hisax_isac.h b/drivers/isdn/hisax/hisax_isac.h
index 08890cf4d9239..d7301da97991e 100644
--- a/drivers/isdn/hisax/hisax_isac.h
+++ b/drivers/isdn/hisax/hisax_isac.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __HISAX_ISAC_H__
 #define __HISAX_ISAC_H__
 
diff --git a/drivers/isdn/i4l/Makefile b/drivers/isdn/i4l/Makefile
index cb9d3bb9fae0a..be77500c9e86f 100644
--- a/drivers/isdn/i4l/Makefile
+++ b/drivers/isdn/i4l/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 # Makefile for the kernel ISDN subsystem and device drivers.
 
 # Each configuration option enables a list of files.
diff --git a/drivers/isdn/mISDN/Makefile b/drivers/isdn/mISDN/Makefile
index 0a6bd2a9e730d..f3b4b7fa85f8e 100644
--- a/drivers/isdn/mISDN/Makefile
+++ b/drivers/isdn/mISDN/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
 #
 # Makefile for the modular ISDN driver
 #
diff --git a/drivers/isdn/mISDN/dsp_hwec.h b/drivers/isdn/mISDN/dsp_hwec.h
index bbca1eb5a8889..c9cb0ea249da0 100644
--- a/drivers/isdn/mISDN/dsp_hwec.h
+++ b/drivers/isdn/mISDN/dsp_hwec.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * dsp_hwec.h
  */
diff --git a/drivers/isdn/mISDN/l1oip.h b/drivers/isdn/mISDN/l1oip.h
index 661c060ada49f..7ea10db20e3a6 100644
--- a/drivers/isdn/mISDN/l1oip.h
+++ b/drivers/isdn/mISDN/l1oip.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * see notice in l1oip.c
  */