[PATCH v6 9/9] selftests: gpio: add test cases for gpio-aggregator

[Koichiro Den <koichiro.den@xxxxxxxxxxxxx>]

Add a set of tests for gpio-aggregator module. This test covers both
pre-existing new_device/delete_device interface and new configfs-based
interface.

Signed-off-by: Koichiro Den <koichiro.den@xxxxxxxxxxxxx>
---
 tools/testing/selftests/gpio/Makefile         |   2 +-
 tools/testing/selftests/gpio/config           |   1 +
 .../testing/selftests/gpio/gpio-aggregator.sh | 723 ++++++++++++++++++
 3 files changed, 725 insertions(+), 1 deletion(-)
 create mode 100755 tools/testing/selftests/gpio/gpio-aggregator.sh

diff --git a/tools/testing/selftests/gpio/Makefile b/tools/testing/selftests/gpio/Makefile
index e0884390447d..7bfe315f7001 100644
--- a/tools/testing/selftests/gpio/Makefile
+++ b/tools/testing/selftests/gpio/Makefile
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
-TEST_PROGS := gpio-mockup.sh gpio-sim.sh
+TEST_PROGS := gpio-mockup.sh gpio-sim.sh gpio-aggregator.sh
 TEST_FILES := gpio-mockup-sysfs.sh
 TEST_GEN_PROGS_EXTENDED := gpio-mockup-cdev gpio-chip-info gpio-line-name
 CFLAGS += -O2 -g -Wall $(KHDR_INCLUDES)
diff --git a/tools/testing/selftests/gpio/config b/tools/testing/selftests/gpio/config
index 409a8532facc..1287abeaac7e 100644
--- a/tools/testing/selftests/gpio/config
+++ b/tools/testing/selftests/gpio/config
@@ -2,3 +2,4 @@ CONFIG_GPIOLIB=y
 CONFIG_GPIO_CDEV=y
 CONFIG_GPIO_MOCKUP=m
 CONFIG_GPIO_SIM=m
+CONFIG_GPIO_AGGREGATOR=m
diff --git a/tools/testing/selftests/gpio/gpio-aggregator.sh b/tools/testing/selftests/gpio/gpio-aggregator.sh
new file mode 100755
index 000000000000..f1bab62c4cd2
--- /dev/null
+++ b/tools/testing/selftests/gpio/gpio-aggregator.sh
@@ -0,0 +1,723 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (C) 2025 Bartosz Golaszewski <brgl@xxxxxxxx>
+# Copyright (C) 2025 Koichiro Den <koichiro.den@xxxxxxxxxxxxx>
+
+BASE_DIR=$(dirname "$0")
+CONFIGFS_SIM_DIR="/sys/kernel/config/gpio-sim"
+CONFIGFS_AGG_DIR="/sys/kernel/config/gpio-aggregator"
+SYSFS_AGG_DIR="/sys/bus/platform/drivers/gpio-aggregator"
+MODULE="gpio-aggregator"
+
+fail() {
+	echo "$*" >&2
+	echo "GPIO $MODULE test FAIL"
+	exit 1
+}
+
+skip() {
+	echo "$*" >&2
+	echo "GPIO $MODULE test SKIP"
+	exit 4
+}
+
+# gpio-sim
+sim_enable_chip() {
+	local CHIP=$1
+
+	echo 1 > "$CONFIGFS_SIM_DIR/$CHIP/live" || fail "Unable to enable the chip"
+}
+
+sim_disable_chip() {
+	local CHIP=$1
+
+	echo 0 > "$CONFIGFS_SIM_DIR/$CHIP/live" || fail "Unable to disable the chip"
+}
+
+sim_configfs_cleanup() {
+	local NOCHECK=${1:-0}
+
+	for CHIP_DIR in "$CONFIGFS_SIM_DIR"/*; do
+		[ -d "$CHIP_DIR" ] || continue
+		echo 0 > "$CHIP_DIR/live"
+		find "$CHIP_DIR" -depth -type d -exec rmdir {} \;
+	done
+	[ "$NOCHECK" -eq 1 ] && return;
+	remaining=$(find "$CONFIGFS_SIM_DIR" -mindepth 1 -type d 2> /dev/null)
+	if [ -n "$remaining" ]; then
+		fail "Directories remain in $CONFIGFS_SIM_DIR: $remaining"
+	fi
+}
+
+sim_get_chip_label() {
+	local CHIP=$1
+	local BANK=$2
+	local CHIP_NAME=$(cat "$CONFIGFS_SIM_DIR/$CHIP/$BANK/chip_name" 2> /dev/null) || \
+		fail "Unable to read the chip name from configfs"
+
+	$BASE_DIR/gpio-chip-info "/dev/$CHIP_NAME" label || \
+		fail "Unable to read the chip label from the character device"
+}
+
+# gpio-aggregator
+agg_create_chip() {
+	local CHIP=$1
+
+	mkdir "$CONFIGFS_AGG_DIR/$CHIP"
+}
+
+agg_remove_chip() {
+	local CHIP=$1
+
+	find "$CONFIGFS_AGG_DIR/$CHIP/" -depth -type d -exec rmdir {} \; || \
+		fail "Unable to remove $CONFIGFS_AGG_DIR/$CHIP"
+}
+
+agg_create_line() {
+	local CHIP=$1
+	local LINE=$2
+
+	mkdir "$CONFIGFS_AGG_DIR/$CHIP/$LINE"
+}
+
+agg_remove_line() {
+	local CHIP=$1
+	local LINE=$2
+
+	rmdir "$CONFIGFS_AGG_DIR/$CHIP/$LINE"
+}
+
+agg_set_key() {
+	local CHIP=$1
+	local LINE=$2
+	local KEY=$3
+
+	echo "$KEY" > "$CONFIGFS_AGG_DIR/$CHIP/$LINE/key" || fail "Unable to set the lookup key"
+}
+
+agg_set_offset() {
+	local CHIP=$1
+	local LINE=$2
+	local OFFSET=$3
+
+	echo "$OFFSET" > "$CONFIGFS_AGG_DIR/$CHIP/$LINE/offset" || \
+		fail "Unable to set the lookup offset"
+}
+
+agg_set_line_name() {
+	local CHIP=$1
+	local LINE=$2
+	local NAME=$3
+
+	echo "$NAME" > "$CONFIGFS_AGG_DIR/$CHIP/$LINE/name" || fail "Unable to set the line name"
+}
+
+agg_enable_chip() {
+	local CHIP=$1
+
+	echo 1 > "$CONFIGFS_AGG_DIR/$CHIP/live" || fail "Unable to enable the chip"
+}
+
+agg_disable_chip() {
+	local CHIP=$1
+
+	echo 0 > "$CONFIGFS_AGG_DIR/$CHIP/live" || fail "Unable to disable the chip"
+}
+
+agg_configfs_cleanup() {
+	local NOCHECK=${1:-0}
+
+	for CHIP_DIR in "$CONFIGFS_AGG_DIR"/*; do
+		[ -d "$CHIP_DIR" ] || continue
+		echo 0 > "$CHIP_DIR/live" 2> /dev/null
+		find "$CHIP_DIR" -depth -type d -exec rmdir {} \;
+	done
+	[ "$NOCHECK" -eq 1 ] && return;
+	remaining=$(find "$CONFIGFS_AGG_DIR" -mindepth 1 -type d 2> /dev/null)
+	if [ -n "$remaining" ]; then
+		fail "Directories remain in $CONFIGFS_AGG_DIR: $remaining"
+	fi
+}
+
+agg_configfs_dev_name() {
+	local CHIP=$1
+
+	cat "$CONFIGFS_AGG_DIR/$CHIP/dev_name" 2> /dev/null || \
+		fail "Unable to read the device name from configfs"
+}
+
+agg_configfs_chip_name() {
+	local CHIP=$1
+	local DEV_NAME=$(agg_configfs_dev_name "$CHIP")
+	local CHIP_LIST=$(find "/sys/devices/platform/$DEV_NAME" \
+		-maxdepth 1 -type d -name "gpiochip[0-9]*" 2> /dev/null)
+	local CHIP_COUNT=$(echo "$CHIP_LIST" | wc -l)
+
+	if [ -z "$CHIP_LIST" ]; then
+		fail "No gpiochip in /sys/devices/platform/$DEV_NAME/"
+	elif [ "$CHIP_COUNT" -ne 1 ]; then
+		fail "Multiple gpiochips unexpectedly found: $CHIP_LIST"
+	fi
+	basename "$CHIP_LIST"
+}
+
+agg_get_chip_num_lines() {
+	local CHIP=$1
+	local N_DIR=$(ls -d $CONFIGFS_AGG_DIR/$CHIP/line[0-9]* 2> /dev/null | wc -l)
+	local N_LINES
+
+	if [ "$(cat $CONFIGFS_AGG_DIR/$CHIP/live)" = 0 ]; then
+		echo "$N_DIR"
+	else
+		N_LINES=$(
+			$BASE_DIR/gpio-chip-info \
+				"/dev/$(agg_configfs_chip_name "$CHIP")" num-lines
+		) || fail "Unable to read the number of lines from the character device"
+		if [ $N_DIR != $N_LINES ]; then
+			fail "Discrepancy between two sources for the number of lines"
+		fi
+		echo "$N_LINES"
+	fi
+}
+
+agg_get_chip_label() {
+	local CHIP=$1
+
+	$BASE_DIR/gpio-chip-info "/dev/$(agg_configfs_chip_name "$CHIP")" label || \
+		fail "Unable to read the chip label from the character device"
+}
+
+agg_get_line_name() {
+	local CHIP=$1
+	local OFFSET=$2
+	local NAME_CONFIGFS=$(cat "$CONFIGFS_AGG_DIR/$CHIP/line${OFFSET}/name")
+	local NAME_CDEV
+
+	if [ "$(cat "$CONFIGFS_AGG_DIR/$CHIP/live")" = 0 ]; then
+		echo "$NAME_CONFIGFS"
+	else
+		NAME_CDEV=$(
+			$BASE_DIR/gpio-line-name \
+				"/dev/$(agg_configfs_chip_name "$CHIP")" "$OFFSET"
+		) || fail "Unable to read the line name from the character device"
+		if [ "$NAME_CONFIGFS" != "$NAME_CDEV" ]; then
+			fail "Discrepancy between two sources for the name of line"
+		fi
+		echo "$NAME_CDEV"
+	fi
+}
+
+
+# Load the modules. This will pull in configfs if needed too.
+modprobe gpio-sim || skip "unable to load the gpio-sim module"
+modprobe gpio-aggregator || skip "unable to load the gpio-aggregator module"
+
+# Make sure configfs is mounted at /sys/kernel/config. Wait a bit if needed.
+for IDX in $(seq 5); do
+	if [ "$IDX" -eq "5" ]; then
+		skip "configfs not mounted at /sys/kernel/config"
+	fi
+
+	mountpoint -q /sys/kernel/config && break
+	sleep 0.1
+done
+
+# If the module was already loaded: remove all previous chips
+agg_configfs_cleanup
+sim_configfs_cleanup
+
+trap "exit 1" SIGTERM SIGINT
+trap "agg_configfs_cleanup 1; sim_configfs_cleanup 1" EXIT
+
+# Use gpio-sim chips as the test backend
+for CHIP in $(seq -f "chip%g" 0 1); do
+	mkdir $CONFIGFS_SIM_DIR/$CHIP
+	for BANK in $(seq -f "bank%g" 0 1); do
+		mkdir -p "$CONFIGFS_SIM_DIR/$CHIP/$BANK"
+		echo "${CHIP}_${BANK}" > "$CONFIGFS_SIM_DIR/$CHIP/$BANK/label" || \
+			fail "unable to set the chip label"
+		echo 16 > "$CONFIGFS_SIM_DIR/$CHIP/$BANK/num_lines" || \
+			fail "unable to set the number of lines"
+		for IDX in $(seq 0 15); do
+			LINE_NAME="${CHIP}${BANK}_${IDX}"
+			LINE_DIR="$CONFIGFS_SIM_DIR/$CHIP/$BANK/line$IDX"
+			mkdir -p $LINE_DIR
+			echo "$LINE_NAME" > "$LINE_DIR/name" || fail "unable to set the line name"
+		done
+	done
+	sim_enable_chip "$CHIP"
+done
+
+echo "1. GPIO aggregator creation/deletion"
+
+echo "1.1. Creation/deletion via configfs"
+
+echo "1.1.1. Minimum creation/deletion"
+agg_create_chip   agg0
+agg_create_line   agg0 line0
+agg_set_key       agg0 line0 "$(sim_get_chip_label chip0 bank0)"
+agg_set_offset    agg0 line0 5
+agg_set_line_name agg0 line0 test0
+agg_enable_chip   agg0
+test "$(cat "$CONFIGFS_AGG_DIR/agg0/live")" = 1 || fail "chip unexpectedly dead"
+test "$(agg_get_chip_label agg0)" = "$(agg_configfs_dev_name agg0)" || \
+	fail "label is inconsistent"
+test "$(agg_get_chip_num_lines agg0)" = "1" || fail "number of lines is not 1"
+test "$(agg_get_line_name agg0 0)" = "test0" || fail "line name is unset"
+agg_disable_chip  agg0
+agg_remove_line   agg0 line0
+agg_remove_chip   agg0
+
+echo "1.1.2. Complex creation/deletion"
+agg_create_chip   agg0
+agg_create_line   agg0 line0
+agg_create_line   agg0 line1
+agg_create_line   agg0 line2
+agg_create_line   agg0 line3
+agg_set_key       agg0 line0 "$(sim_get_chip_label chip0 bank0)"
+agg_set_key       agg0 line1 "$(sim_get_chip_label chip0 bank1)"
+agg_set_key       agg0 line2 "$(sim_get_chip_label chip1 bank0)"
+agg_set_key       agg0 line3 "$(sim_get_chip_label chip1 bank1)"
+agg_set_offset    agg0 line0 1
+agg_set_offset    agg0 line1 3
+agg_set_offset    agg0 line2 5
+agg_set_offset    agg0 line3 7
+agg_set_line_name agg0 line0 test0
+agg_set_line_name agg0 line1 test1
+agg_set_line_name agg0 line2 test2
+agg_set_line_name agg0 line3 test3
+agg_enable_chip   agg0
+test "$(cat "$CONFIGFS_AGG_DIR/agg0/live")" = 1 || fail "chip unexpectedly dead"
+test "$(agg_get_chip_label agg0)" = "$(agg_configfs_dev_name agg0)" || \
+	fail "label is inconsistent"
+test "$(agg_get_chip_num_lines agg0)" = "4" || fail "number of lines is not 1"
+test "$(agg_get_line_name agg0 0)" = "test0" || fail "line name is unset"
+test "$(agg_get_line_name agg0 1)" = "test1" || fail "line name is unset"
+test "$(agg_get_line_name agg0 2)" = "test2" || fail "line name is unset"
+test "$(agg_get_line_name agg0 3)" = "test3" || fail "line name is unset"
+agg_disable_chip  agg0
+agg_remove_line   agg0 line0
+agg_remove_line   agg0 line1
+agg_remove_line   agg0 line2
+agg_remove_line   agg0 line3
+agg_remove_chip   agg0
+
+echo "1.1.3. Can't instantiate a chip without any line"
+agg_create_chip   agg0
+echo 1 > "$CONFIGFS_AGG_DIR/agg0/live" 2> /dev/null && fail "chip unexpectedly enabled"
+test "$(cat "$CONFIGFS_AGG_DIR/agg0/live")" = 0 || fail "chip unexpectedly alive"
+agg_remove_chip   agg0
+
+echo "1.1.4. Can't instantiate a chip with invalid configuration"
+agg_create_chip   agg0
+agg_create_line   agg0 line0
+agg_set_key       agg0 line0 "chipX_bankX"
+agg_set_offset    agg0 line0 99
+agg_set_line_name agg0 line0 test0
+echo 1 > "$CONFIGFS_AGG_DIR/agg0/live" 2> /dev/null && fail "chip unexpectedly enabled"
+test "$(cat "$CONFIGFS_AGG_DIR/agg0/live")" = 0 || fail "chip unexpectedly alive"
+agg_remove_line   agg0 line0
+agg_remove_chip   agg0
+
+echo "1.1.5. Can't instantiate a chip asynchronously via deferred probe"
+agg_create_chip   agg0
+agg_create_line   agg0 line0
+agg_set_key       agg0 line0 "chip0_bank0"
+agg_set_offset    agg0 line0 5
+agg_set_line_name agg0 line0 test0
+sim_disable_chip  chip0
+echo 1 > "$CONFIGFS_AGG_DIR/agg0/live" 2> /dev/null && fail "chip unexpectedly enabled"
+test "$(cat "$CONFIGFS_AGG_DIR/agg0/live")" = 0 || fail "chip unexpectedly alive"
+sim_enable_chip   chip0
+sleep 1
+test "$(cat "$CONFIGFS_AGG_DIR/agg0/live")" = 0 || \
+	fail "chip unexpectedly transitioned to 'live' state"
+agg_remove_line   agg0 line0
+agg_remove_chip   agg0
+
+echo "1.2. Creation/deletion via sysfs"
+
+echo "1.2.1. Minimum creation/deletion"
+echo "chip0_bank0 0" > "$SYSFS_AGG_DIR/new_device"
+CHIPNAME=$(agg_configfs_chip_name _sysfs.0)
+test "$(cat "$CONFIGFS_AGG_DIR/_sysfs.0/live")" = 1 || fail "chip unexpectedly dead"
+test "$(agg_get_chip_label _sysfs.0)" = "$(agg_configfs_dev_name _sysfs.0)" || \
+	fail "label is inconsistent"
+test "$(agg_get_chip_num_lines _sysfs.0)" = "1" || fail "number of lines is not 1"
+test "$(agg_get_line_name _sysfs.0 0)" = "" || fail "line name is unset"
+echo "$(agg_configfs_dev_name _sysfs.0)" > "$SYSFS_AGG_DIR/delete_device"
+test -d $CONFIGFS_AGG_DIR/_sysfs.0 && fail "_sysfs.0 unexpectedly remains"
+test -d /dev/${CHIPNAME} && fail "/dev/${CHIPNAME} unexpectedly remains"
+
+echo "1.2.2. Complex creation/deletion"
+echo "chip0bank0_0 chip1_bank1 10-11" > "$SYSFS_AGG_DIR/new_device"
+CHIPNAME=$(agg_configfs_chip_name _sysfs.0)
+test "$(cat "$CONFIGFS_AGG_DIR/_sysfs.0/live")" = 1 || fail "chip unexpectedly dead"
+test "$(agg_get_chip_label _sysfs.0)" = "$(agg_configfs_dev_name _sysfs.0)" || \
+	fail "label is inconsistent"
+test "$(agg_get_chip_num_lines _sysfs.0)" = "3" || fail "number of lines is not 3"
+test "$(agg_get_line_name _sysfs.0 0)" = "" || fail "line name is unset"
+test "$(agg_get_line_name _sysfs.0 1)" = "" || fail "line name is unset"
+test "$(agg_get_line_name _sysfs.0 2)" = "" || fail "line name is unset"
+echo "$(agg_configfs_dev_name _sysfs.0)" > "$SYSFS_AGG_DIR/delete_device"
+test -d $CONFIGFS_AGG_DIR/_sysfs.0 && fail "_sysfs.0 unexpectedly remains"
+test -d /dev/${CHIPNAME} && fail "/dev/${CHIPNAME} unexpectedly remains"
+
+echo "1.2.3. Asynchronous creation with deferred probe"
+sim_disable_chip  chip0
+echo 'chip0_bank0 0' > $SYSFS_AGG_DIR/new_device
+sleep 1
+test "$(cat "$CONFIGFS_AGG_DIR/_sysfs.0/live")" = 0 || fail "chip unexpectedly alive"
+sim_enable_chip  chip0
+sleep 1
+CHIPNAME=$(agg_configfs_chip_name _sysfs.0)
+test "$(cat "$CONFIGFS_AGG_DIR/_sysfs.0/live")" = 1 || fail "chip unexpectedly remains dead"
+test "$(agg_get_chip_label _sysfs.0)" = "$(agg_configfs_dev_name _sysfs.0)" || \
+	fail "label is inconsistent"
+test "$(agg_get_chip_num_lines _sysfs.0)" = "1" || fail "number of lines is not 1"
+test "$(agg_get_line_name _sysfs.0 0)" = "" || fail "line name unexpectedly set"
+echo "$(agg_configfs_dev_name _sysfs.0)" > "$SYSFS_AGG_DIR/delete_device"
+test -d $CONFIGFS_AGG_DIR/_sysfs.0 && fail "_sysfs.0 unexpectedly remains"
+test -d /dev/${CHIPNAME} && fail "/dev/${CHIPNAME} unexpectedly remains"
+
+echo "1.2.4. Can't instantiate a chip with invalid configuration"
+echo "xyz 0" > "$SYSFS_AGG_DIR/new_device"
+test "$(cat $CONFIGFS_AGG_DIR/_sysfs.0/live)" = 0 || fail "chip unexpectedly alive"
+echo "$(agg_configfs_dev_name _sysfs.0)" > "$SYSFS_AGG_DIR/delete_device"
+
+echo "2. GPIO aggregator configuration"
+
+echo "2.1. Configuring aggregators instantiated via configfs"
+setup_2_1() {
+	agg_create_chip   agg0
+	agg_create_line   agg0 line0
+	agg_create_line   agg0 line1
+	agg_set_key       agg0 line0 "$(sim_get_chip_label chip0 bank0)"
+	agg_set_key       agg0 line1 "$(sim_get_chip_label chip1 bank0)"
+	agg_set_offset    agg0 line0 1
+	agg_set_offset    agg0 line1 3
+	agg_set_line_name agg0 line0 test0
+	agg_set_line_name agg0 line1 test1
+	agg_enable_chip   agg0
+}
+teardown_2_1() {
+	agg_configfs_cleanup
+}
+
+echo "2.1.1. While offline"
+
+echo "2.1.1.1. Line can be added/removed"
+setup_2_1
+agg_disable_chip  agg0
+agg_create_line   agg0 line2
+agg_set_key       agg0 line2 "$(sim_get_chip_label chip0 bank1)"
+agg_set_offset    agg0 line2 5
+agg_enable_chip   agg0
+test "$(agg_get_chip_num_lines agg0)" = "3" || fail "number of lines is not 1"
+teardown_2_1
+
+echo "2.1.1.2. Line key can be modified"
+setup_2_1
+agg_disable_chip  agg0
+agg_set_key       agg0 line0 "$(sim_get_chip_label chip0 bank1)"
+agg_set_key       agg0 line1 "$(sim_get_chip_label chip1 bank1)"
+agg_enable_chip   agg0
+teardown_2_1
+
+echo "2.1.1.3. Line name can be modified"
+setup_2_1
+agg_disable_chip  agg0
+agg_set_line_name agg0 line0 new0
+agg_set_line_name agg0 line1 new1
+agg_enable_chip   agg0
+test "$(agg_get_line_name agg0 0)" = "new0" || fail "line name is unset"
+test "$(agg_get_line_name agg0 1)" = "new1" || fail "line name is unset"
+teardown_2_1
+
+echo "2.1.1.4. Line offset can be modified"
+setup_2_1
+agg_disable_chip  agg0
+agg_set_offset    agg0 line0 5
+agg_set_offset    agg0 line1 7
+agg_enable_chip   agg0
+teardown_2_1
+
+echo "2.1.1.5. Can re-enable a chip after valid reconfiguration"
+setup_2_1
+agg_disable_chip  agg0
+agg_set_key       agg0 line0 "$(sim_get_chip_label chip1 bank1)"
+agg_set_offset    agg0 line0 15
+agg_set_key       agg0 line1 "$(sim_get_chip_label chip0 bank1)"
+agg_set_offset    agg0 line0 14
+agg_create_line   agg0 line2
+agg_set_key       agg0 line2 "$(sim_get_chip_label chip0 bank1)"
+agg_set_offset    agg0 line2 13
+agg_enable_chip   agg0
+test "$(agg_get_chip_num_lines agg0)" = "3" || fail "number of lines is not 1"
+teardown_2_1
+
+echo "2.1.1.7. Can't re-enable a chip with invalid reconfiguration"
+setup_2_1
+agg_disable_chip  agg0
+agg_set_key       agg0 line0 invalidkey
+echo 1 > "$CONFIGFS_AGG_DIR/agg0/live" 2> /dev/null && fail "chip unexpectedly enabled"
+teardown_2_1
+setup_2_1
+agg_disable_chip  agg0
+agg_set_offset    agg0 line0 99
+echo 1 > "$CONFIGFS_AGG_DIR/agg0/live" 2> /dev/null && fail "chip unexpectedly enabled"
+teardown_2_1
+
+echo "2.1.2. While online"
+
+echo "2.1.2.1. Can't add/remove line"
+setup_2_1
+mkdir "$CONFIGFS_AGG_DIR/agg0/line2" 2> /dev/null && fail "line unexpectedly added"
+rmdir "$CONFIGFS_AGG_DIR/agg0/line1" 2> /dev/null && fail "line unexpectedly removed"
+teardown_2_1
+
+echo "2.1.2.2. Can't modify line key"
+setup_2_1
+echo "chip1_bank1" > "$CONFIGFS_AGG_DIR/agg0/line0/key" 2> /dev/null && \
+	fail "lookup key unexpectedly updated"
+teardown_2_1
+
+echo "2.1.2.3. Can't modify line name"
+setup_2_1
+echo "new0" > "$CONFIGFS_AGG_DIR/agg0/line0/name" 2> /dev/null && \
+	fail "name unexpectedly updated"
+teardown_2_1
+
+echo "2.1.2.4. Can't modify line offset"
+setup_2_1
+echo "5" > "$CONFIGFS_AGG_DIR/agg0/line0/offset" 2> /dev/null && \
+	fail "offset unexpectedly updated"
+teardown_2_1
+
+echo "2.2. Configuring aggregators instantiated via sysfs"
+setup_2_2() {
+	echo "chip0_bank0 1 chip1_bank0 3" > "$SYSFS_AGG_DIR/new_device"
+}
+teardown_2_2() {
+	echo "$(agg_configfs_dev_name _sysfs.0)" > "$SYSFS_AGG_DIR/delete_device"
+}
+
+echo "2.2.1. While online"
+
+echo "2.2.1.1. Can toggle live"
+setup_2_2
+agg_disable_chip  _sysfs.0
+agg_enable_chip   _sysfs.0
+teardown_2_2
+
+echo "2.2.1.2. Can't add/remove line"
+setup_2_2
+mkdir "$CONFIGFS_AGG_DIR/_sysfs.0/line2" 2> /dev/null && fail "line unexpectedly added"
+rmdir "$CONFIGFS_AGG_DIR/_sysfs.0/line1" 2> /dev/null && fail "line unexpectedly removed"
+teardown_2_2
+
+echo "2.2.1.3. Can't modify line key"
+setup_2_2
+echo "chip1_bank1" > "$CONFIGFS_AGG_DIR/_sysfs.0/line0/key" 2> /dev/null && \
+	fail "lookup key unexpectedly updated"
+teardown_2_2
+
+echo "2.2.1.4. Can't modify line name"
+setup_2_2
+echo "new0" > "$CONFIGFS_AGG_DIR/_sysfs.0/line0/name" 2> /dev/null && \
+	fail "name unexpectedly updated"
+teardown_2_2
+
+echo "2.2.1.5. Can't modify line offset"
+setup_2_2
+echo "5" > "$CONFIGFS_AGG_DIR/_sysfs.0/line0/offset" 2> /dev/null && \
+	fail "offset unexpectedly updated"
+teardown_2_2
+
+echo "2.2.2. While waiting for deferred probe"
+
+echo "2.2.2.1. Can't add/remove line despite live = 0"
+sim_disable_chip chip0
+setup_2_2
+mkdir "$CONFIGFS_AGG_DIR/_sysfs.0/line2" 2> /dev/null && fail "line unexpectedly added"
+rmdir "$CONFIGFS_AGG_DIR/_sysfs.0/line1" 2> /dev/null && fail "line unexpectedly removed"
+teardown_2_2
+sim_enable_chip chip0
+
+echo "2.2.2.2. Can't modify line key"
+sim_disable_chip chip0
+setup_2_2
+echo "chip1_bank1" > "$CONFIGFS_AGG_DIR/_sysfs.0/line0/key" 2> /dev/null && \
+	fail "lookup key unexpectedly updated"
+teardown_2_2
+sim_enable_chip chip0
+
+echo "2.2.2.3. Can't modify line name"
+sim_disable_chip chip0
+setup_2_2
+echo "new0" > "$CONFIGFS_AGG_DIR/_sysfs.0/line0/name" 2> /dev/null && \
+	fail "name unexpectedly updated"
+teardown_2_2
+sim_enable_chip chip0
+
+echo "2.2.2.4. Can't modify line offset"
+sim_disable_chip chip0
+setup_2_2
+echo 5 > "$CONFIGFS_AGG_DIR/_sysfs.0/line0/offset" 2> /dev/null && \
+	fail "offset unexpectedly updated"
+teardown_2_2
+sim_enable_chip chip0
+
+echo "2.2.2.5. Can't toggle live"
+sim_disable_chip chip0
+setup_2_2
+test "$(cat "$CONFIGFS_AGG_DIR/_sysfs.0/live")" = 0 || fail "chip unexpectedly alive"
+echo 1 > "$CONFIGFS_AGG_DIR/_sysfs.0/live" 2> /dev/null && fail "chip unexpectedly enabled"
+teardown_2_2
+sim_enable_chip chip0
+
+echo "2.2.3. While offline"
+
+echo "2.2.3.1. Can't add/remove line despite live = 0"
+setup_2_2
+agg_disable_chip _sysfs.0
+mkdir "$CONFIGFS_AGG_DIR/_sysfs.0/line2" 2> /dev/null && fail "line unexpectedly added"
+rmdir "$CONFIGFS_AGG_DIR/_sysfs.0/line1" 2> /dev/null && fail "line unexpectedly removed"
+teardown_2_2
+
+echo "2.2.3.2. Line key can be modified"
+setup_2_2
+agg_disable_chip  _sysfs.0
+agg_set_key       _sysfs.0 line0 "$(sim_get_chip_label chip0 bank1)"
+agg_set_key       _sysfs.0 line1 "$(sim_get_chip_label chip1 bank1)"
+agg_enable_chip   _sysfs.0
+teardown_2_2
+
+echo "2.2.3.3. Line name can be modified"
+setup_2_2
+agg_disable_chip  _sysfs.0
+agg_set_line_name _sysfs.0 line0 new0
+agg_set_line_name _sysfs.0 line1 new1
+agg_enable_chip   _sysfs.0
+test "$(agg_get_line_name _sysfs.0 0)" = "new0" || fail "line name is unset"
+test "$(agg_get_line_name _sysfs.0 1)" = "new1" || fail "line name is unset"
+teardown_2_2
+
+echo "2.2.3.4. Line offset can be modified"
+setup_2_2
+agg_disable_chip  _sysfs.0
+agg_set_offset    _sysfs.0 line0 5
+agg_set_offset    _sysfs.0 line1 7
+agg_enable_chip   _sysfs.0
+teardown_2_2
+
+echo "2.2.3.5. Can re-enable a chip with valid reconfiguration"
+setup_2_2
+agg_disable_chip  _sysfs.0
+agg_set_key       _sysfs.0 line0 "$(sim_get_chip_label chip1 bank1)"
+agg_set_offset    _sysfs.0 line0 15
+agg_set_key       _sysfs.0 line1 "$(sim_get_chip_label chip0 bank1)"
+agg_set_offset    _sysfs.0 line0 14
+agg_enable_chip   _sysfs.0
+teardown_2_2
+
+echo "2.2.3.6. Can't re-enable a chip with invalid reconfiguration"
+setup_2_2
+agg_disable_chip  _sysfs.0
+agg_set_key       _sysfs.0 line0 invalidkey
+echo 1 > "$CONFIGFS_AGG_DIR/_sysfs.0/live" 2> /dev/null && fail "chip unexpectedly enabled"
+teardown_2_2
+setup_2_2
+agg_disable_chip  _sysfs.0
+agg_set_offset    _sysfs.0 line0 99
+echo 1 > "$CONFIGFS_AGG_DIR/_sysfs.0/live" 2> /dev/null && fail "chip unexpectedly enabled"
+teardown_2_2
+
+echo "3. Module unload"
+
+echo "3.1. Can't unload module if there is at least one device created via configfs"
+agg_create_chip agg0
+modprobe -r gpio-aggregator 2> /dev/null
+test -d /sys/module/gpio_aggregator || fail "module unexpectedly unloaded"
+agg_remove_chip agg0
+
+echo "3.2. Can unload module if there is no device created via configfs"
+echo "chip0_bank0 1 chip1_bank0 3" > "$SYSFS_AGG_DIR/new_device"
+modprobe -r gpio-aggregator 2> /dev/null
+test -d /sys/module/gpio_aggregator && fail "module unexpectedly remains to be loaded"
+modprobe gpio-aggregator 2> /dev/null
+
+echo "4. GPIO forwarder functional"
+SETTINGS="chip0:bank0:2 chip0:bank1:4 chip1:bank0:6 chip1:bank1:8"
+setup_4() {
+	local OFFSET=0
+	agg_create_chip agg0
+	for SETTING in $SETTINGS; do
+		CHIP=$(echo "$SETTING" | cut -d: -f1)
+		BANK=$(echo "$SETTING" | cut -d: -f2)
+		LINE=$(echo "$SETTING" | cut -d: -f3)
+		agg_create_line agg0 "line${OFFSET}"
+		agg_set_key     agg0 "line${OFFSET}" "$(sim_get_chip_label "$CHIP" "$BANK")"
+		agg_set_offset  agg0 "line${OFFSET}" "$LINE"
+		OFFSET=$(expr $OFFSET + 1)
+	done
+	agg_enable_chip agg0
+}
+teardown_4() {
+	agg_configfs_cleanup
+}
+
+echo "4.1. Forwarding set values"
+setup_4
+OFFSET=0
+for SETTING in $SETTINGS; do
+	CHIP=$(echo "$SETTING" | cut -d: -f1)
+	BANK=$(echo "$SETTING" | cut -d: -f2)
+	LINE=$(echo "$SETTING" | cut -d: -f3)
+	DEVNAME=$(cat "$CONFIGFS_SIM_DIR/$CHIP/dev_name")
+	CHIPNAME=$(cat "$CONFIGFS_SIM_DIR/$CHIP/$BANK/chip_name")
+	VAL_PATH="/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio${LINE}/value"
+	test $(cat $VAL_PATH) = "0" || fail "incorrect value read from sysfs"
+	$BASE_DIR/gpio-mockup-cdev -s 1 "/dev/$(agg_configfs_chip_name agg0)" "$OFFSET" &
+	mock_pid=$!
+	sleep 0.1 # FIXME Any better way?
+	test "$(cat $VAL_PATH)" = "1" || fail "incorrect value read from sysfs"
+	kill "$mock_pid"
+	OFFSET=$(expr $OFFSET + 1)
+done
+teardown_4
+
+echo "4.2. Forwarding set config"
+setup_4
+OFFSET=0
+for SETTING in $SETTINGS; do
+	CHIP=$(echo "$SETTING" | cut -d: -f1)
+	BANK=$(echo "$SETTING" | cut -d: -f2)
+	LINE=$(echo "$SETTING" | cut -d: -f3)
+	DEVNAME=$(cat "$CONFIGFS_SIM_DIR/$CHIP/dev_name")
+	CHIPNAME=$(cat "$CONFIGFS_SIM_DIR/$CHIP/$BANK/chip_name")
+	VAL_PATH="/sys/devices/platform/$DEVNAME/$CHIPNAME/sim_gpio${LINE}/value"
+	$BASE_DIR/gpio-mockup-cdev -b pull-up "/dev/$(agg_configfs_chip_name agg0)" "$OFFSET"
+	test $(cat "$VAL_PATH") = "1" || fail "incorrect value read from sysfs"
+	OFFSET=$(expr $OFFSET + 1)
+done
+teardown_4
+
+echo "5. Race condition verification"
+
+echo "5.1. Stress test of new_device/delete_device and module load/unload"
+for _ in $(seq 1000); do
+	{
+		echo "dummy 0" > "$SYSFS_AGG_DIR/new_device"
+		cat "$CONFIGFS_AGG_DIR/_sysfs.0/dev_name" > "$SYSFS_AGG_DIR/delete_device"
+	} 2> /dev/null
+done &
+writer_pid=$!
+while kill -0 "$writer_pid" 2> /dev/null; do
+	{
+		modprobe gpio-aggregator
+		modprobe -r gpio-aggregator
+	} 2> /dev/null
+done
+
+echo "GPIO $MODULE test PASS"
-- 
2.45.2