guess: Add device-tree feature

This feature scans the device tree [1] for compatible nodes and
determines which kernel modules are required for the current hardware.
It is intended to be used in embedded linux environments where device
trees are used to describe hardware.

[1] https://www.devicetree.org/specifications/

Signed-off-by: Alexey Gladkov <[email protected]>

Author: legionus

guess/device-tree/README.md

@@ -0,0 +1,8 @@
+# Guess module: device tree
+
+This feature scans the device tree [1] for compatible nodes and determines which
+kernel modules are required for the current hardware. It is intended to be used
+in embedded linux environments where device trees are used to describe hardware.
+
+[1] https://www.devicetree.org/specifications/
+[2] https://github.com/devicetree-org/devicetree-specification

guess/device-tree/action

@@ -0,0 +1,34 @@
+#!/bin/bash -eu
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+. guess-functions
+
+$TRACE_SOURCE "Processing ..."
+
+dt_dir=
+
+for dir in ${DEVICETREE_PATH-} "$PROCFS_PATH"/device-tree "$SYSFS_PATH"/firmware/devicetree/base; do
+	if [ -e "$dir" ] && [ -f "$dir"/compatible ]; then
+		dt_dir="$dir"
+		break
+	fi
+done
+
+[ -n "$dt_dir" ] ||
+	exit 0
+
+find "$dt_dir/" -name compatible |
+while read -r dt_compatible; do
+	tr '\0' '\n' < "$dt_compatible" |
+	while read -r compat; do
+		printf 'of:N*T*C%sC*\n' "${compat//[ 	]/_}"
+	done
+done |
+	sort -u |
+	depinfo ${KERNEL:+-k "$KERNEL"} --no-prefix --input=- 2>/dev/null |
+	sed -r -n -e 's,^.*/lib/modules/[^/]+/,,p' |
+	filter_device_tree_modules |
+while read -r mod; do
+	mod="${mod##*/}"
+	guess_optional_module "${mod%.ko}"
+done

guess/device-tree/rules.mk

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+PHONY += guess-device-tree
+
+guess-device-tree:
+	$V echo "Processing $@ ..."
+	@ GUESS_SUFFIX=add:$@ \
+	    $(DETECTDIR)/device-tree/action
+
+guess: guess-device-tree

guess/loaded-modules/action

@@ -37,20 +37,7 @@ list_builtin_modules()
 	list_loaded_modules
 	list_builtin_modules
 } |
-	grep -E \
-		-e '^kernel/drivers/bus/' \
-		-e '^kernel/drivers/clk/' \
-		-e '^kernel/drivers/dma/' \
-		-e '^kernel/drivers/i2c/' \
-		-e '^kernel/drivers/mfd/' \
-		-e '^kernel/drivers/mmc/' \
-		-e '^kernel/drivers/nvmem/' \
-		-e '^kernel/drivers/phy/' \
-		-e '^kernel/drivers/power/supply/' \
-		-e '^kernel/drivers/regulator/' \
-		-e '^kernel/drivers/reset/' \
-		-e '^kernel/drivers/soc/' \
-		-e '^kernel/drivers/usb/phy/' |
+	filter_device_tree_modules |
 while read -r mod; do
 	mod="${mod##*/}"
 	guess_optional_module "${mod%.ko}"

tools/guess-functions

@@ -189,4 +189,23 @@ is_active_feature()
 	return 1
 }
 
+filter_device_tree_modules()
+{
+	grep -E \
+		-e '^kernel/drivers/bus/' \
+		-e '^kernel/drivers/clk/' \
+		-e '^kernel/drivers/dma/' \
+		-e '^kernel/drivers/i2c/' \
+		-e '^kernel/drivers/mfd/' \
+		-e '^kernel/drivers/mmc/' \
+		-e '^kernel/drivers/nvmem/' \
+		-e '^kernel/drivers/phy/' \
+		-e '^kernel/drivers/power/supply/' \
+		-e '^kernel/drivers/regulator/' \
+		-e '^kernel/drivers/reset/' \
+		-e '^kernel/drivers/soc/' \
+		-e '^kernel/drivers/usb/phy/' \
+	#
+}
+
 fi #__included_make_initrd_guess_functions