1.首先加载驱动 insmod smart210_led.ko

2.open( /dev/设备文件名 ,O_RDWR)

3.用ioctl(fd,LED_ON,value) 操作led

第二个参数可以为LED_ON,LED_OFF,LED_ALL

当为LED_ON时第三个参数只能取值1-4 （说明点亮固定led，若第三个参数为3表示点亮第三个led）

当为LED_OFF时第三个参数只能取值1-4 （说明熄灭固定led，若第三个参数为3表示熄灭第三个led）

当为LED_OFF时第三个参数取值0-15 第三个参数的值化为四位二进制，每一位对应一个led，点亮为1，熄灭为0.

-1 first load the driver of insmod smart210_led.ko

2.open ("　/dev/ device file name, "　O_RDWR)

3 with IOCTL (FD, LED_ON, value)　LED operation

The second parameter can be LED_ON, LED_OFF, LED_ALL

When LED_ON third parameters only value of 1-4 (light fixed led, that if the third parameters for the 3 said light third LED)

When LED_OFF third parameters only value of 1-4 (that goes out the fixed led, if the third parameters for the 3 represent the third led out)

When LED_OFF third parameter 0-15 values of third parameters into four bit binary, each corresponding to a LED, light is 1, out of 0