OpenWrt增加Led

环境

硬件：HLK_MTK7628n系统：官方Openwrt分支：master

海凌科提供的OpenWrt 系统太老，是的版本，于是下载最新版本进行编译。编译步骤参考L大的lede项目说明。（ps：最先是使用lede进行的开发，后来发现mosquitto不能正常使用，折腾了好几天没有找到解决方案，于是回归到原版Openwrt）

硬件连接

将 4个网口的led释放，用于单独控制。

操作步骤

1.修改dts文件

打开target/linux/ramips/dts/mt7628an_hilink_hlk-7628n.dts修改如下：

// SPDX-License-Identifier: GPL-2.0-or-later OR MIT#include "mt7628an.dtsi"#include <dt-bindings/gpio/gpio.h>#include <dt-bindings/input/input.h>/ {compatible = "hilink,hlk-7628n", "mediatek,mt7628an-soc";model = "HILINK HLK-7628N";keys {compatible = "gpio-keys";reset {label = "reset";gpios = <&gpio 38 GPIO_ACTIVE_LOW>;linux,code = <KEY_RESTART>;};};leds {compatible = "gpio-leds";wlan {label = "green:wlan";gpios = <&gpio 44 GPIO_ACTIVE_LOW>;};led1 {label = "led1";gpios = <&gpio 42 GPIO_ACTIVE_LOW>;};led2 {label = "led2";gpios = <&gpio 41 GPIO_ACTIVE_LOW>;};led3 {label = "led3";gpios = <&gpio 40 GPIO_ACTIVE_LOW>;};led4 {label = "led4";gpios = <&gpio 39 GPIO_ACTIVE_LOW>;};};};&state_default {gpio {groups = "i2c","p1led_an", "p2led_an","p3led_an", "p4led_an";function = "gpio";};};&uart1 {status = "okay";};&spi0 {status = "okay";flash@0 {compatible = "jedec,spi-nor";reg = <0>;spi-max-frequency = <10000000>;broken-flash-reset;partitions {compatible = "fixed-partitions";#address-cells = <1>;#size-cells = <1>;partition@0 {label = "u-boot";reg = <0x0 0x30000>;read-only;};partition@30000 {label = "u-boot-env";reg = <0x30000 0x10000>;read-only;};factory: partition@40000 {label = "factory";reg = <0x40000 0x10000>;read-only;};partition@50000 {compatible = "denx,uimage";label = "firmware";reg = <0x50000 0x1fb0000>;};};};};&ethernet {mtd-mac-address = <&factory 0x28>;};&wmac {status = "okay";};

重点观察leds和state_default部分

2.重新编译

make cleanmake

生成镜像后通过web或者uboot烧录到板子中，进入系统进行测试

3.测试

系统启动后，串口控制台进入路径

cd /sys/devices/platform/leds/leds/

查看支持的led

ls

操作某一个led，注意操作某一个led就得进入该文件夹

cd led1

ls

各个含义如下：

brightness 控制亮度todo 补充

点灯操作

echo 1 > brightnessecho 0 > brightness

有效果：可以点亮、关闭网络指示灯

原理

dts文件中p2led_an对应的io是在哪里定义的呢，是在驱动文件中，如下

驱动文件所在位置

/home/luke/openwrt/lede/build_dir/toolchain-mipsel_24kc_gcc-8.4.0_musl/linux-5.4.158/arch/mips/ralink/mt7620.c

驱动和dts一一对应。