【versal】【petalinux】添加LED驱动

提示：本文使用外部kernel与uboot

一、LED

1.1 LED功能

向节点中brightness写1，点亮LED；写0，关闭led。

1.2 LED节点

/sys/class/leds/pwr/brightness
/sys/class/leds/alarm/brightness
/sys/class/leds/fauit/brightness

1.3 LED操作命令

1.3.1 点LED

echo 1 > /sys/class/leds/pwr/brightness
echo 1 > /sys/class/leds/alarm/brightness
echo 1 > /sys/class/leds/fauit/brightness

1.3.2 关闭LED

echo 0 > /sys/class/leds/pwr/brightness
echo 0 > /sys/class/leds/alarm/brightness
echo 0