1
2 # SPDX-License-Identifier: GPL-2.0
3
4 # Overrides functions in gpio-mockup.sh to test using the GPIO SYSFS uAPI
5
6 SYSFS=`grep -w sysfs /proc/mounts | cut -f2 -d' '`
7 [ -d "$SYSFS" ] || skip "sysfs is not mounted"
8
9 GPIO_SYSFS="${SYSFS}/class/gpio"
10 [ -d "$GPIO_SYSFS" ] || skip "CONFIG_GPIO_SYSFS is not selected"
11
12 PLATFORM_SYSFS=$SYSFS/devices/platform
13
14 sysfs_nr=
15 sysfs_ldir=
16
17 # determine the sysfs GPIO number given the $chip and $offset
18 # e.g. gpiochip1:32
19 find_sysfs_nr()
20 {
21 # e.g. /sys/devices/platform/gpio-mockup.1/gpiochip1
22 local platform=$(find $PLATFORM_SYSFS -mindepth 2 -maxdepth 2 -type d -name $chip)
23 [ "$platform" ] || fail "can't find platform of $chip"
24 # e.g. /sys/devices/platform/gpio-mockup.1/gpio/gpiochip508/base
25 local base=$(find ${platform%/*}/gpio/ -mindepth 2 -maxdepth 2 -type f -name base)
26 [ "$base" ] || fail "can't find base of $chip"
27 sysfs_nr=$(($(< "$base") + $offset))
28 sysfs_ldir="$GPIO_SYSFS/gpio$sysfs_nr"
29 }
30
31 acquire_line()
32 {
33 [ "$sysfs_nr" ] && return
34 find_sysfs_nr
35 echo "$sysfs_nr" > "$GPIO_SYSFS/export"
36 }
37
38 # The helpers being overridden...
39 get_line()
40 {
41 [ -e "$sysfs_ldir/value" ] && echo $(< "$sysfs_ldir/value")
42 }
43
44 set_line()
45 {
46 acquire_line
47
48 for option in $*; do
49 case $option in
50 active-high)
51 echo 0 > "$sysfs_ldir/active_low"
52 ;;
53 active-low)
54 echo 1 > "$sysfs_ldir/active_low"
55 ;;
56 input)
57 echo "in" > "$sysfs_ldir/direction"
58 ;;
59 0)
60 echo "out" > "$sysfs_ldir/direction"
61 echo 0 > "$sysfs_ldir/value"
62 ;;
63 1)
64 echo "out" > "$sysfs_ldir/direction"
65 echo 1 > "$sysfs_ldir/value"
66 ;;
67 esac
68 done
69 }
70
71 release_line()
72 {
73 [ "$sysfs_nr" ] || return 0
74 echo "$sysfs_nr" > "$GPIO_SYSFS/unexport"
75 sysfs_nr=
76 sysfs_ldir=
77 }
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