selftests: gpio: rework and simplify test implementation

The GPIO mockup selftests are overly complicated with separate
implementations of the tests for sysfs and cdev uAPI, and with the cdev
implementation being dependent on tools/gpio and libmount.

Rework the test implementation to provide a common test suite with a
simplified pluggable uAPI interface.  The cdev implementation utilises
the GPIO uAPI directly to remove the dependence on tools/gpio.
The simplified uAPI interface removes the need for any file system mount
checks in C, and so removes the dependence on libmount.

The rework also fixes the sysfs test implementation which has been broken
since the device created in the multiple gpiochip case was split into
separate devices.

Fixes: 8a39f597bcfd ("gpio: mockup: rework device probing")
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

1 files changed, 55 insertions, 113 deletions

diff --git a/tools/testing/selftests/gpio/gpio-mockup-sysfs.sh b/tools/testing/selftests/gpio/gpio-mockup-sysfs.sh
index dd269d877562..2d2e5d8763b6 100755
--- a/tools/testing/selftests/gpio/gpio-mockup-sysfs.sh
+++ b/tools/testing/selftests/gpio/gpio-mockup-sysfs.sh
@@ -1,135 +1,77 @@
 
 # SPDX-License-Identifier: GPL-2.0
-is_consistent()
-{
-	val=
-
-	active_low_sysfs=`cat $GPIO_SYSFS/gpio$nr/active_low`
-	val_sysfs=`cat $GPIO_SYSFS/gpio$nr/value`
-	dir_sysfs=`cat $GPIO_SYSFS/gpio$nr/direction`
 
-	gpio_this_debugfs=`cat $GPIO_DEBUGFS |grep "gpio-$nr" | sed "s/(.*)//g"`
-	dir_debugfs=`echo $gpio_this_debugfs | awk '{print $2}'`
-	val_debugfs=`echo $gpio_this_debugfs | awk '{print $3}'`
-	if [ $val_debugfs = "lo" ]; then
-		val=0
-	elif [ $val_debugfs = "hi" ]; then
-		val=1
-	fi
+# Overrides functions in gpio-mockup.sh to test using the GPIO SYSFS uAPI
 
-	if [ $active_low_sysfs = "1" ]; then
-		if [ $val = "0" ]; then
-			val="1"
-		else
-			val="0"
-		fi
-	fi
+SYSFS=`grep -w sysfs /proc/mounts | cut -f2 -d' '`
+[ -d "$SYSFS" ] || skip "sysfs is not mounted"
 
-	if [ $val_sysfs = $val ] && [ $dir_sysfs = $dir_debugfs ]; then
-		echo -n "."
-	else
-		echo "test fail, exit"
-		die
-	fi
-}
+GPIO_SYSFS="${SYSFS}/class/gpio"
+[ -d "$GPIO_SYSFS" ] || skip "CONFIG_GPIO_SYSFS is not selected"
 
-test_pin_logic()
-{
-	nr=$1
-	direction=$2
-	active_low=$3
-	value=$4
+PLATFORM_SYSFS=$SYSFS/devices/platform
 
-	echo $direction > $GPIO_SYSFS/gpio$nr/direction
-	echo $active_low > $GPIO_SYSFS/gpio$nr/active_low
-	if [ $direction = "out" ]; then
-		echo $value > $GPIO_SYSFS/gpio$nr/value
-	fi
-	is_consistent $nr
-}
+sysfs_nr=
+sysfs_ldir=
 
-test_one_pin()
+# determine the sysfs GPIO number given the $chip and $offset
+# e.g. gpiochip1:32
+find_sysfs_nr()
 {
-	nr=$1
-
-	echo -n "test pin<$nr>"
-
-	echo $nr > $GPIO_SYSFS/export 2>/dev/null
-
-	if [ X$? != X0 ]; then
-		echo "test GPIO pin $nr failed"
-		die
-	fi
-
-	#"Checking if the sysfs is consistent with debugfs: "
-	is_consistent $nr
-
-	#"Checking the logic of active_low: "
-	test_pin_logic $nr out 1 1
-	test_pin_logic $nr out 1 0
-	test_pin_logic $nr out 0 1
-	test_pin_logic $nr out 0 0
-
-	#"Checking the logic of direction: "
-	test_pin_logic $nr in 1 1
-	test_pin_logic $nr out 1 0
-	test_pin_logic $nr low 0 1
-	test_pin_logic $nr high 0 0
-
-	echo $nr > $GPIO_SYSFS/unexport
-
-	echo "successful"
+	# e.g. /sys/devices/platform/gpio-mockup.1/gpiochip1
+	local platform=$(find $PLATFORM_SYSFS -mindepth 2 -maxdepth 2 -type d -name $chip)
+	[ "$platform" ] || fail "can't find platform of $chip"
+	# e.g. /sys/devices/platform/gpio-mockup.1/gpio/gpiochip508/base
+	local base=$(find ${platform%/*}/gpio/ -mindepth 2 -maxdepth 2 -type f -name base)
+	[ "$base" ] || fail "can't find base of $chip"
+	sysfs_nr=$(($(< "$base") + $offset))
+	sysfs_ldir="$GPIO_SYSFS/gpio$sysfs_nr"
 }
 
-test_one_pin_fail()
+acquire_line()
 {
-	nr=$1
-
-	echo $nr > $GPIO_SYSFS/export 2>/dev/null
-
-	if [ X$? != X0 ]; then
-		echo "test invalid pin $nr successful"
-	else
-		echo "test invalid pin $nr failed"
-		echo $nr > $GPIO_SYSFS/unexport 2>/dev/null
-		die
-	fi
+	[ "$sysfs_nr" ] && return
+	find_sysfs_nr
+	echo "$sysfs_nr" > "$GPIO_SYSFS/export"
 }
 
-list_chip()
+# The helpers being overridden...
+get_line()
 {
-	echo `ls -d $GPIO_DRV_SYSFS/gpiochip* 2>/dev/null`
+	[ -e "$sysfs_ldir/value" ] && echo $(< "$sysfs_ldir/value")
 }
 
-test_chip()
+set_line()
 {
-	chip=$1
-	name=`basename $chip`
-	base=`cat $chip/base`
-	ngpio=`cat $chip/ngpio`
-	printf "%-10s %-5s %-5s\n" $name $base $ngpio
-	if [ $ngpio = "0" ]; then
-		echo "number of gpio is zero is not allowed".
-	fi
-	test_one_pin $base
-	test_one_pin $(($base + $ngpio - 1))
-	test_one_pin $((( RANDOM % $ngpio )  + $base ))
+	acquire_line
+
+	for option in $*; do
+		case $option in
+		active-high)
+			echo 0 > "$sysfs_ldir/active_low"
+			;;
+		active-low)
+			echo 1 > "$sysfs_ldir/active_low"
+			;;
+		input)
+			echo "in" > "$sysfs_ldir/direction"
+			;;
+		0)
+			echo "out" > "$sysfs_ldir/direction"
+			echo 0 > "$sysfs_ldir/value"
+			;;
+		1)
+			echo "out" > "$sysfs_ldir/direction"
+			echo 1 > "$sysfs_ldir/value"
+			;;
+		esac
+	done
 }
 
-test_chips_sysfs()
+release_line()
 {
-       gpiochip=`list_chip $module`
-       if [ X"$gpiochip" = X ]; then
-               if [ X"$valid" = Xfalse ]; then
-                       echo "successful"
-               else
-                       echo "fail"
-                       die
-               fi
-       else
-               for chip in $gpiochip; do
-                       test_chip $chip
-               done
-       fi
+	[ "$sysfs_nr" ] || return 0
+	echo "$sysfs_nr" > "$GPIO_SYSFS/unexport"
+	sysfs_nr=
+	sysfs_ldir=
 }
-