Add .editorconfig file for basic formatting

EditorConfig is a specification to define the most basic code formatting
stuff, and it's supported by many editors and IDEs, either directly or
via plugins, including VSCode/VSCodium, Vim, emacs and more.

It allows to define formatting style related to indentation, charset,
end of lines and trailing whitespaces. It also allows to apply different
formats for different files based on wildcards, so for example it is
possible to apply different configs to *.{c,h}, *.py and *.rs.

In linux project, defining a .editorconfig might help to those people
that work on different projects with different indentation styles, so
they cannot define a global style. Now they will directly see the
correct indentation on every fresh clone of the project.

See https://editorconfig.org

Co-developed-by: Danny Lin <danny@kdrag0n.dev>
Signed-off-by: Danny Lin <danny@kdrag0n.dev>
Signed-off-by: Íñigo Huguet <ihuguet@redhat.com>
Acked-by: Mickaël Salaün <mic@digikod.net>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Tested-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

4 files changed, 41 insertions, 0 deletions

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 000000000000..854773350cc5
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,32 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+root = true
+
+[{*.{awk,c,dts,dtsi,dtso,h,mk,s,S},Kconfig,Makefile,Makefile.*}]
+charset = utf-8
+end_of_line = lf
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = tab
+indent_size = 8
+
+[*.{json,py,rs}]
+charset = utf-8
+end_of_line = lf
+trim_trailing_whitespace = true
+insert_final_newline = true
+indent_style = space
+indent_size = 4
+
+# this must be below the general *.py to overwrite it
+[tools/{perf,power,rcu,testing/kunit}/**.py,]
+indent_style = tab
+indent_size = 8
+
+[*.yaml]
+charset = utf-8
+end_of_line = lf
+trim_trailing_whitespace = unset
+insert_final_newline = true
+indent_style = space
+indent_size = 2
diff --git a/.gitignore b/.gitignore
index 98274e1160d7..689a4fa3f547 100644
--- a/.gitignore
+++ b/.gitignore
@@ -96,6 +96,7 @@ modules.order
 #
 !.clang-format
 !.cocciconfig
+!.editorconfig
 !.get_maintainer.ignore
 !.gitattributes
 !.gitignore
diff --git a/Documentation/process/4.Coding.rst b/Documentation/process/4.Coding.rst
index 1f0d81f44e14..c2046dec0c2f 100644
--- a/Documentation/process/4.Coding.rst
+++ b/Documentation/process/4.Coding.rst
@@ -66,6 +66,10 @@ for aligning variables/macros, for reflowing text and other similar tasks.
 See the file :ref:`Documentation/process/clang-format.rst <clangformat>`
 for more details.
 
+Some basic editor settings, such as indentation and line endings, will be
+set automatically if you are using an editor that is compatible with
+EditorConfig. See the official EditorConfig website for more information:
+https://editorconfig.org/
 
 Abstraction layers
 ******************
diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst
index 6db37a46d305..c48382c6b477 100644
--- a/Documentation/process/coding-style.rst
+++ b/Documentation/process/coding-style.rst
@@ -735,6 +735,10 @@ for aligning variables/macros, for reflowing text and other similar tasks.
 See the file :ref:`Documentation/process/clang-format.rst <clangformat>`
 for more details.
 
+Some basic editor settings, such as indentation and line endings, will be
+set automatically if you are using an editor that is compatible with
+EditorConfig. See the official EditorConfig website for more information:
+https://editorconfig.org/
 
 10) Kconfig configuration files
 -------------------------------