1 files changed, 403 insertions, 0 deletions
diff --git a/tools/testing/selftests/gpio/gpio-mockup.sh b/tools/testing/selftests/gpio/gpio-mockup.sh
new file mode 100755
index 0000000000..0d6c5f7f95
--- /dev/null
+++ b/tools/testing/selftests/gpio/gpio-mockup.sh
@@ -0,0 +1,403 @@
+#!/bin/bash -efu
+# SPDX-License-Identifier: GPL-2.0
+
+#exit status
+#0: success
+#1: fail
+#4: skip test - including run as non-root user
+
+BASE=${0%/*}
+DEBUGFS=
+GPIO_DEBUGFS=
+dev_type="cdev"
+module="gpio-mockup"
+verbose=
+full_test=
+random=
+uapi_opt=
+active_opt=
+bias_opt=
+line_set_pid=
+
+# Kselftest return codes
+ksft_fail=1
+ksft_skip=4
+
+usage()
+{
+	echo "Usage:"
+	echo "$0 [-frv] [-t type]"
+	echo "-f:  full test (minimal set run by default)"
+	echo "-r:  test random lines as well as fence posts"
+	echo "-t:  interface type:"
+	echo "      cdev (character device ABI) - default"
+	echo "      cdev_v1 (deprecated character device ABI)"
+	echo "      sysfs (deprecated SYSFS ABI)"
+	echo "-v:  verbose progress reporting"
+	exit $ksft_fail
+}
+
+skip()
+{
+	echo "$*" >&2
+	echo "GPIO $module test SKIP"
+	exit $ksft_skip
+}
+
+prerequisite()
+{
+	[ $(id -u) -eq 0 ] || skip "must be run as root"
+
+	DEBUGFS=$(grep -w debugfs /proc/mounts | cut -f2 -d' ')
+	[ -d "$DEBUGFS" ] || skip "debugfs is not mounted"
+
+	GPIO_DEBUGFS=$DEBUGFS/$module
+}
+
+remove_module()
+{
+	modprobe -r -q $module
+}
+
+cleanup()
+{
+	set +e
+	release_line
+	remove_module
+	jobs -p | xargs -r kill > /dev/null 2>&1
+}
+
+fail()
+{
+	echo "test failed: $*" >&2
+	echo "GPIO $module test FAIL"
+	exit $ksft_fail
+}
+
+try_insert_module()
+{
+	modprobe -q $module "$1" || fail "insert $module failed with error $?"
+}
+
+log()
+{
+	[ -z "$verbose" ] || echo "$*"
+}
+
+# The following line helpers, release_Line, get_line and set_line, all
+# make use of the global $chip and $offset variables.
+#
+# This implementation drives the GPIO character device (cdev) uAPI.
+# Other implementations may override these to test different uAPIs.
+
+# Release any resources related to the line
+release_line()
+{
+	[ "$line_set_pid" ] && kill $line_set_pid && wait $line_set_pid || true
+	line_set_pid=
+}
+
+# Read the current value of the line
+get_line()
+{
+	release_line
+
+	local cdev_opts=${uapi_opt}${active_opt}
+	$BASE/gpio-mockup-cdev $cdev_opts /dev/$chip $offset
+	echo $?
+}
+
+# Set the state of the line
+#
+# Changes to line configuration are provided as parameters.
+# The line is assumed to be an output if the line value 0 or 1 is
+# specified, else an input.
+set_line()
+{
+	local val=
+
+	release_line
+
+	# parse config options...
+	for option in $*; do
+		case $option in
+		active-low)
+			active_opt="-l "
+			;;
+		active-high)
+			active_opt=
+			;;
+		bias-none)
+			bias_opt=
+			;;
+		pull-down)
+			bias_opt="-bpull-down "
+			;;
+		pull-up)
+			bias_opt="-bpull-up "
+			;;
+		0)
+			val=0
+			;;
+		1)
+			val=1
+			;;
+		esac
+	done
+
+	local cdev_opts=${uapi_opt}${active_opt}
+	if [ "$val" ]; then
+		$BASE/gpio-mockup-cdev $cdev_opts -s$val /dev/$chip $offset &
+		# failure to set is detected by reading mockup and toggling values
+		line_set_pid=$!
+		# allow for gpio-mockup-cdev to launch and request line
+		# (there is limited value in checking if line has been requested)
+		sleep 0.01
+	elif [ "$bias_opt" ]; then
+		cdev_opts=${cdev_opts}${bias_opt}
+		$BASE/gpio-mockup-cdev $cdev_opts /dev/$chip $offset || true
+	fi
+}
+
+assert_line()
+{
+	local val
+	# don't need any retry here as set_mock allows for propagation
+	val=$(get_line)
+	[ "$val" = "$1" ] || fail "line value is ${val:-empty} when $1 was expected"
+}
+
+# The following mockup helpers all make use of the $mock_line
+assert_mock()
+{
+	local backoff_wait=10
+	local retry=0
+	local val
+	# retry allows for set propagation from uAPI to mockup
+	while true; do
+		val=$(< $mock_line)
+		[ "$val" = "$1" ] && break
+		retry=$((retry + 1))
+		[ $retry -lt 5 ] || fail "mockup $mock_line value ${val:-empty} when $1 expected"
+		sleep $(printf "%0.2f" $((backoff_wait))e-3)
+		backoff_wait=$((backoff_wait * 2))
+	done
+}
+
+set_mock()
+{
+	echo "$1" > $mock_line
+	# allow for set propagation - so we won't be in a race with set_line
+	assert_mock "$1"
+}
+
+# test the functionality of a line
+#
+# The line is set from the mockup side and is read from the userspace side
+# (input), and is set from the userspace side and is read from the mockup side
+# (output).
+#
+# Setting the mockup pull using the userspace interface bias settings is
+# tested where supported by the userspace interface (cdev).
+test_line()
+{
+	chip=$1
+	offset=$2
+	log "test_line $chip $offset"
+	mock_line=$GPIO_DEBUGFS/$chip/$offset
+	[ -e "$mock_line" ] || fail "missing line $chip:$offset"
+
+	# test input active-high
+	set_mock 1
+	set_line input active-high
+	assert_line 1
+	set_mock 0
+	assert_line 0
+	set_mock 1
+	assert_line 1
+
+	if [ "$full_test" ]; then
+		if [ "$dev_type" != "sysfs" ]; then
+			# test pulls
+			set_mock 0
+			set_line input pull-up
+			assert_line 1
+			set_mock 0
+			assert_line 0
+
+			set_mock 1
+			set_line input pull-down
+			assert_line 0
+			set_mock 1
+			assert_line 1
+
+			set_line bias-none
+		fi
+
+		# test input active-low
+		set_mock 0
+		set_line active-low
+		assert_line 1
+		set_mock 1
+		assert_line 0
+		set_mock 0
+		assert_line 1
+
+		# test output active-high
+		set_mock 1
+		set_line active-high 0
+		assert_mock 0
+		set_line 1
+		assert_mock 1
+		set_line 0
+		assert_mock 0
+	fi
+
+	# test output active-low
+	set_mock 0
+	set_line active-low 0
+	assert_mock 1
+	set_line 1
+	assert_mock 0
+	set_line 0
+	assert_mock 1
+
+	release_line
+}
+
+test_no_line()
+{
+	log test_no_line "$*"
+	[ ! -e "$GPIO_DEBUGFS/$1/$2" ] || fail "unexpected line $1:$2"
+}
+
+# Load the module and check that the expected number of gpiochips, with the
+# expected number of lines, are created and are functional.
+#
+# $1 is the gpio_mockup_ranges parameter for the module
+# The remaining parameters are the number of lines, n, expected for each of
+# the gpiochips expected to be created.
+#
+# For each gpiochip the fence post lines, 0 and n-1, are tested, and the
+# line on the far side of the fence post, n, is tested to not exist.
+#
+# If the $random flag is set then a random line in the middle of the
+# gpiochip is tested as well.
+insmod_test()
+{
+	local ranges=
+	local gc=
+	local width=
+
+	[ "${1:-}" ] || fail "missing ranges"
+	ranges=$1 ; shift
+	try_insert_module "gpio_mockup_ranges=$ranges"
+	log "GPIO $module test with ranges: <$ranges>:"
+	# e.g. /sys/kernel/debug/gpio-mockup/gpiochip1
+	gpiochip=$(find "$DEBUGFS/$module/" -name gpiochip* -type d | sort)
+	for chip in $gpiochip; do
+		gc=${chip##*/}
+		[ "${1:-}" ] || fail "unexpected chip - $gc"
+		width=$1 ; shift
+		test_line $gc 0
+		if [ "$random" -a $width -gt 2 ]; then
+			test_line $gc $((RANDOM % ($width - 2) + 1))
+		fi
+		test_line $gc $(($width - 1))
+		test_no_line $gc $width
+	done
+	[ "${1:-}" ] && fail "missing expected chip of width $1"
+	remove_module || fail "failed to remove module with error $?"
+}
+
+while getopts ":frvt:" opt; do
+	case $opt in
+	f)
+		full_test=true
+		;;
+	r)
+		random=true
+		;;
+	t)
+		dev_type=$OPTARG
+		;;
+	v)
+		verbose=true
+		;;
+	*)
+		usage
+		;;
+	esac
+done
+shift $((OPTIND - 1))
+
+[ "${1:-}" ] && fail "unknown argument '$1'"
+
+prerequisite
+
+trap 'exit $ksft_fail' SIGTERM SIGINT
+trap cleanup EXIT
+
+case "$dev_type" in
+sysfs)
+	source $BASE/gpio-mockup-sysfs.sh
+	echo "WARNING: gpio sysfs ABI is deprecated."
+	;;
+cdev_v1)
+	echo "WARNING: gpio cdev ABI v1 is deprecated."
+	uapi_opt="-u1 "
+	;;
+cdev)
+	;;
+*)
+	fail "unknown interface type: $dev_type"
+	;;
+esac
+
+remove_module || fail "can't remove existing $module module"
+
+# manual gpio allocation tests fail if a physical chip already exists
+[ "$full_test" -a -e "/dev/gpiochip0" ] && skip "full tests conflict with gpiochip0"
+
+echo "1.  Module load tests"
+echo "1.1.  dynamic allocation of gpio"
+insmod_test "-1,32" 32
+insmod_test "-1,23,-1,32" 23 32
+insmod_test "-1,23,-1,26,-1,32" 23 26 32
+if [ "$full_test" ]; then
+	echo "1.2.  manual allocation of gpio"
+	insmod_test "0,32" 32
+	insmod_test "0,32,32,60" 32 28
+	insmod_test "0,32,40,64,64,96" 32 24 32
+	echo "1.3.  dynamic and manual allocation of gpio"
+	insmod_test "-1,32,32,62" 32 30
+	insmod_test "-1,22,-1,23,0,24,32,64" 22 23 24 32
+	insmod_test "-1,32,32,60,-1,29" 32 28 29
+	insmod_test "-1,32,40,64,-1,5" 32 24 5
+	insmod_test "0,32,32,44,-1,22,-1,31" 32 12 22 31
+fi
+echo "2.  Module load error tests"
+echo "2.1 gpio overflow"
+# Currently: The max number of gpio(1024) is defined in arm architecture.
+insmod_test "-1,1024"
+if [ "$full_test" ]; then
+	echo "2.2 no lines defined"
+	insmod_test "0,0"
+	echo "2.3 ignore range overlap"
+	insmod_test "0,32,0,1" 32
+	insmod_test "0,32,1,5" 32
+	insmod_test "0,32,30,35" 32
+	insmod_test "0,32,31,32" 32
+	insmod_test "10,32,30,35" 22
+	insmod_test "10,32,9,14" 22
+	insmod_test "0,32,20,21,40,56" 32 16
+	insmod_test "0,32,32,64,32,40" 32 32
+	insmod_test "0,32,32,64,36,37" 32 32
+	insmod_test "0,32,35,64,34,36" 32 29
+	insmod_test "0,30,35,64,35,45" 30 29
+	insmod_test "0,32,40,56,30,33" 32 16
+	insmod_test "0,32,40,56,30,41" 32 16
+	insmod_test "0,32,40,56,39,45" 32 16
+fi
+
+echo "GPIO $module test PASS"