rk3288 LED上添加heartbeat功能

sdchy

　　平台：瑞芯的rk3288
作者：fulinux
*****本文允许转载，不过请注明出处：http://blog.iyunv.com/fulinus****



1、硬件环境
任意选取一个GPIO引脚作为heartbeat的输出，选择一个未被使用的SPI0_CSn0，如底板原理图所示：
对应在顶板上连接rk3288的是GPIO5 _ B5 _ u引脚，如图：
2、软件环境
在kernel/arch/arm/boot/dts/rk3288-tb_8846.dts文件中配置如下：
diff --git a/arch/arm/boot/dts/rk3288-tb_8846.dts b/arch/arm/boot/dts/rk3288-tb_8846.dts
index c92d973..91ad1da 100644
--- a/arch/arm/boot/dts/rk3288-tb_8846.dts
+++ b/arch/arm/boot/dts/rk3288-tb_8846.dts
@@ -6,6 +6,16 @@
#include "vtl_ts_sdk8846.dtsi"
/ {
+    leds {
+        compatible = "gpio-leds";
+        led0 {
+            label = "led0";
+            gpios = <&gpio5 GPIO_B5 GPIO_ACTIVE_HIGH>;
+            linux,default-trigger = &quot;heartbeat&quot;;
+            default-state = &quot;off&quot;;
+        };
+    };
+
fiq-debugger {
status = &quot;okay&quot;;
};
内核配置如下：--- LED Support
<*>   LED Support for GPIO connected LEDs

   LED Trigger support  ---> <*>   LED Heartbeat Trigger正常编译后烧录到开发板上，通过示波器可以看到心跳波形：