util: Add tool to generate cros_ec_commands.h

Add a rule to generate a new cros_ec_commands.h when ec_commands.h is
modified. The rule is checked when buildall is invoked.

At Presubmit stage, check a cros_ec_commands.h exists if ec_commands.h
is modified.

The CL author is responsible to upstream that file.

BUG=chromium:945948
BRANCH=none
Cq-Depend: chromium:1558853
TEST=Check manually cros_ec_commands.h is generated with
make build_cros_ec_commands
Check no bread crumbs are left-over when the rule fails.
Check checkpatch triggers when it finds an invalid syntax in the output
file.
Check ../../repohooks/pre-upload.py returns a meaningful error when
cros_ec_commands.h file is not present.

Change-Id: Ibc8ed7165914d39b5f0bd41643932a8514768925
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1559380
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>

Makefile.rules

@@ -164,7 +164,7 @@ build_boards: | $(FAILED_BOARDS_DIR)
 	$(MAKE) try_build_boards
 
 .PHONY: buildall
-buildall: build_boards
+buildall: build_boards build_cros_ec_commands
 	$(MAKE) build_cts
 	$(MAKE) buildfuzztests
 	$(MAKE) runtests
@@ -758,6 +758,12 @@ stats: build_boards
 	$(call cmd_stats,RO)
 	$(call cmd_stats,RW)
 
+.PHONY: build_cros_ec_commands
+build_cros_ec_commands: build/kernel/include/linux/mfd/cros_ec_commands.h
+
+build/kernel/include/linux/mfd/cros_ec_commands.h: include/ec_commands.h
+	util/make_linux_ec_commands_h.sh $< $@
+
 .SECONDARY:
 
 -include $(deps)

PRESUBMIT.cfg

@@ -12,6 +12,7 @@ checkpatch_check: --no-tree --ignore=MSLEEP,VOLATILE,SPDX_LICENSE_TAG
 kerneldoc_check: --include_regex=\bec_commands\.h$
 
 [Hook Scripts]
-presubmit_check = util/presubmit_check.sh 2>&1
-config_option_check = util/config_option_check.py 2>&1
-host_command_check = util/host_command_check.sh 2>&1
+presubmit_check = util/presubmit_check.sh
+config_option_check = util/config_option_check.py
+host_command_check = util/host_command_check.sh
+ec_commands_h = util/linux_ec_commands_h_check.sh

util/linux_ec_commands_h_check.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+#
+# Copyright 2019 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+set -e
+
+ec_commands_file_in="include/ec_commands.h"
+ec_commands_file_out="build/kernel/include/linux/mfd/cros_ec_commands.h"
+
+# Check if ec_commands.h has changed.
+echo ${PRESUBMIT_FILES} | grep -q "${ec_commands_file_in}" || exit 0
+
+if [ ! -f "${ec_commands_file_out}" ]; then
+  echo "A new cros_ec_commands.h must be generated."
+  echo 'Please run "make buildall" or "make build_cros_ec_commands"'.
+  exit 1
+fi
+
+if [ "${ec_commands_file_out}" -ot "${ec_commands_file_in}" ]; then
+  echo "cros_ec_commands.h is out of date."
+  echo 'Please run "make buildall" or "make build_cros_ec_commands"'.
+  exit 1
+fi

util/make_linux_ec_commands_h.sh

@@ -0,0 +1,70 @@
+#!/bin/bash
+#
+# Copyright 2019 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Generate a kernel include file from ec_commands.h.
+
+usage() {
+  cat << EOF
+Generate an ec_commands.h file suitable for upstreaming to kernel.org.
+Syntax:
+$0 source_ec_commands.h target_cros_ec_commands.h
+
+source_ec_commands.h: source file, usually include/ec_commands.h
+target_cros_ec_commands.h: target file that will be upstreamed.
+EOF
+}
+
+set -e
+
+in="$1"
+out="$2"
+
+if [ $# -ne 2 ]; then
+  usage
+  exit 1
+fi
+
+out_dir="$(dirname "${out}")"
+mkdir -p "${out_dir}"
+tmp="$(mktemp -p "${out_dir}" cros_ec_XXX.h)"
+cp "${in}" "${tmp}"
+
+cleanup() {
+  rm -f "${tmp}"*
+}
+
+trap cleanup EXIT
+
+# Replace license
+patch "${tmp}" << EOF
+@@ -1,6 +1,11 @@
+-/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+- * Use of this source code is governed by a BSD-style license that can be
+- * found in the LICENSE file.
++/* SPDX-License-Identifier: GPL-2.0 */
++/*
++ * Host communication command constants for ChromeOS EC
++ *
++ * Copyright (C) 2012 Google, Inc
++ *
++ * NOTE: This file is auto-generated from ChromeOS EC Open Source code from
++ * https://chromium.googlesource.com/chromiumos/platform/ec/+/master/include/ec_commands.h
+  */
+ 
+ /* Host communication command constants for Chrome EC */
+EOF
+
+# Change header guards
+sed -i "s/__CROS_EC_EC_COMMANDS_H/__CROS_EC_COMMANDS_H/" "${tmp}"
+
+# Remove non kernel code to prevent checkpatch warnings and simplify the .h.
+unifdef -x2 -m -UCONFIG_HOSTCMD_ALIGNED -U__ACPI__ -D__KERNEL__ -U__cplusplus \
+  -UCHROMIUM_EC "${tmp}"
+
+# Check kernel checkpatch passes.
+"${CROS_WORKON_SRCROOT}/src/repohooks/checkpatch.pl" -f "${tmp}"
+
+cp "${tmp}" "${out}"