v4l2: Relicense V4L2 compatibility layer under LGPL

The V4L2 compatibility layer is licensed under the GPL. It is compiled
as a binary separate from libcamera.so, and is loaded into the address
space of processes through LD_PRELOAD to intercept calls to the C
library.

It is our understanding and intent that the GPL license doesn't
propagate to the binaries whose calls are intercepted, considering those
binaries are not derivative work of the V4L2 compatibility layer and are
not designed to be linked to the V4L2 compatibility layer. There is
however a possibly grey area if binaries are packaged with a shell
script wrapper that loads the V4L2 compatibility layer. This could lead
to license-related issues if such packaging is performed by Linux
distributions or system integrators.

To clarify the intent and lift the doubts, relicense the V4L2
compatibility layer under the LGPL. The V4L2 compatibility layer code
itself still benefits from the license protection, while its usage with
third-party binaries is clearly allowed as intended.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>
Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Acked-by: Paul Elder <paul.elder@ideasonboard.com>
Acked-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Acked-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>

7 files changed, 7 insertions, 7 deletions

diff --git a/src/v4l2/v4l2_camera.cpp b/src/v4l2/v4l2_camera.cpp
index 50a4121c..4da01a45 100644
--- a/src/v4l2/v4l2_camera.cpp
+++ b/src/v4l2/v4l2_camera.cpp
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
  * Copyright (C) 2019, Google Inc.
  *
diff --git a/src/v4l2/v4l2_camera.h b/src/v4l2/v4l2_camera.h
index c969130f..303eda44 100644
--- a/src/v4l2/v4l2_camera.h
+++ b/src/v4l2/v4l2_camera.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
  * Copyright (C) 2019, Google Inc.
  *
diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
index 19e8f6d3..3df4d42b 100644
--- a/src/v4l2/v4l2_camera_proxy.cpp
+++ b/src/v4l2/v4l2_camera_proxy.cpp
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
  * Copyright (C) 2019, Google Inc.
  *
diff --git a/src/v4l2/v4l2_camera_proxy.h b/src/v4l2/v4l2_camera_proxy.h
index e15b230d..af9f9bbe 100644
--- a/src/v4l2/v4l2_camera_proxy.h
+++ b/src/v4l2/v4l2_camera_proxy.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
  * Copyright (C) 2019, Google Inc.
  *
diff --git a/src/v4l2/v4l2_compat.cpp b/src/v4l2/v4l2_compat.cpp
index a162037f..2a9a1762 100644
--- a/src/v4l2/v4l2_compat.cpp
+++ b/src/v4l2/v4l2_compat.cpp
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
  * Copyright (C) 2019, Google Inc.
  *
diff --git a/src/v4l2/v4l2_compat_manager.cpp b/src/v4l2/v4l2_compat_manager.cpp
index cd8ac0b8..2338a0ee 100644
--- a/src/v4l2/v4l2_compat_manager.cpp
+++ b/src/v4l2/v4l2_compat_manager.cpp
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
  * Copyright (C) 2019, Google Inc.
  *
diff --git a/src/v4l2/v4l2_compat_manager.h b/src/v4l2/v4l2_compat_manager.h
index 872c7c3b..14338a59 100644
--- a/src/v4l2/v4l2_compat_manager.h
+++ b/src/v4l2/v4l2_compat_manager.h
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
 /*
  * Copyright (C) 2019, Google Inc.
  *