base-files: implemented basic GPIO control

Internal GPIO pins are used for PoE passthrough setups in multi-port
routers. This patch implemnets control over this hardware feature for
Ubiquiti Nanostations and TP-Link CPE510.

Signed-off-by: Lars Kruse <lists@sumpfralle.de>

SVN-Revision: 46271

package/base-files/files/etc/init.d/gpio_switch

+#!/bin/sh /etc/rc.common
+# Copyright (C) 2015 OpenWrt.org
+
+START=98
+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 "$gpio_path" ] || sleep 1
+		echo out >"$gpio_path/direction"
+	}
+	# write 0 or 1 to the "value" field
+	{ [ "$value" = "0" ] && echo "0" || echo "1"; } >"$gpio_path/value"
+}
+
+service_triggers()
+{
+	procd_add_reload_trigger "system"
+}
+
+start_service()
+{
+	[ -e /sys/class/gpio/ ] && {
+		config_load system
+		config_foreach load_gpio_switch gpio_switch
+	}
+}

package/base-files/files/lib/functions/uci-defaults.sh

@@ -2,6 +2,7 @@
 # Copyright (C) 2011 OpenWrt.org
 
 UCIDEF_LEDS_CHANGED=0
+UCIDEF_GPIO_SWITCHES_CHANGED=0
 
 ucidef_set_led_netdev() {
 	local cfg="led_$1"
@@ -180,6 +181,29 @@ ucidef_commit_leds()
 	[ "$UCIDEF_LEDS_CHANGED" = "1" ] && uci commit system
 }
 
+ucidef_set_gpio_switch() {
+	local cfg="gpio_switch_$1"
+	local name="$2"
+	local gpio_pin="$3"
+	# use "0" as default value
+	local default="${4:-0}"
+
+	uci -q get "system.$cfg" && return 0
+
+	uci batch <<EOF
+set system.$cfg='gpio_switch'
+set system.$cfg.name='$name'
+set system.$cfg.gpio_pin='$gpio_pin'
+set system.$cfg.value='$default'
+EOF
+	UCIDEF_GPIO_SWITCHES_CHANGED=1
+}
+
+ucidef_commit_gpio_switches()
+{
+	[ "$UCIDEF_GPIO_SWITCHES_CHANGED" = "1" ] && uci commit system
+}
+
 ucidef_set_interface_loopback() {
 	uci batch <<EOF
 set network.loopback='interface'

target/linux/ar71xx/base-files/etc/uci-defaults/01_gpio-switches

+#!/bin/sh
+#
+# Copyright (C) 2015 OpenWrt.org
+#
+
+. /lib/functions/uci-defaults.sh
+. /lib/ar71xx.sh
+
+board=$(ar71xx_board_name)
+
+case "$board" in
+nanostation-m)
+	ucidef_set_gpio_switch "poe_passthrough" "PoE Passthrough" "2"
+	;;
+nanostation-m-xw)
+	ucidef_set_gpio_switch "poe_passthrough" "PoE Passthrough" "8"
+	;;
+cpe510)
+	ucidef_set_gpio_switch "poe_passthrough" "PoE Passthrough" "20"
+	;;
+esac
+
+ucidef_commit_gpio_switches
+
+exit 0