openwrt/package/base-files/files/etc/init.d/gpio_switch
Mathias Kresin acafbac4b3 base-files: gpio switch: check if direction can be set
Obviously not all GPIO controller allow to change the direction. The issue
is around since the beginning of the script but only due to the recent
changes error messages are more visible.

Add a check if a change of the direction is supported by the GPIO
controller and fallback to setting only the value if not.

Fixes: FS#1271
Signed-off-by: Mathias Kresin <dev@kresin.me>
2018-01-18 07:22:37 +01:00

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#!/bin/sh /etc/rc.common
# Copyright (C) 2015 OpenWrt.org
START=94
STOP=10
USE_PROCD=1
load_gpio_switch()
{
local name
local gpio_pin
local value
config_get gpio_pin "$1" gpio_pin
config_get name "$1" name
config_get value "$1" value 0
local gpio_path="/sys/class/gpio/gpio${gpio_pin}"
# export GPIO pin for access
[ -d "$gpio_path" ] || {
echo "$gpio_pin" >/sys/class/gpio/export
# we need to wait a bit until the GPIO appears
[ -d "$gpio_path" ] || sleep 1
}
# direction attribute only exists if the kernel supports changing the
# direction of a GPIO
if [ -e "${gpio_path}/direction" ]; then
# set the pin to output with high or low pin value
{ [ "$value" = "0" ] && echo "low" || echo "high"; } >"$gpio_path/direction"
else
{ [ "$value" = "0" ] && echo "0" || echo "1"; } >"$gpio_path/value"
fi
}
service_triggers()
{
procd_add_reload_trigger "system"
}
start_service()
{
[ -e /sys/class/gpio/ ] && {
config_load system
config_foreach load_gpio_switch gpio_switch
}
}