type),(nr),0)
#define _IOR(type,nr,size) _IOC(_IOC_READ,(type),(nr),(_IOC_TYPECHECK(size)))
#define _IOW...size)))
对于实际gpio驱动的编写,我们可以做如下的交互协议
#define IOCTL_MAGIC 'g'
#define GPIO_OUT_LOW _IOW...(IOCTL_MAGIC, 0x00, unsigned long)
#define GPIO_OUT_HIG _IOW(IOCTL_MAGIC, 0x01, unsigned long)...0
#define IOCTL_MAGIC 'g'
#define GPIO_OUT_LOW _IOW(IOCTL_MAGIC, 0x00, unsigned long...(GPIO_IOC_MAGIC, IOC_OUTPUT_CLR, unsigned int)
#define GPIO_IOC_OUTPUT_HIG _IOW(GPIO_IOC_MAGIC