如果按照上一篇记录的那样,只有本公司的人或者自己才能使用驱动。想写出一个通用的驱动程序,让其他应用程序来无缝移植,需要使用现成的驱动——输入子系统。
/drivers/input/input.c
#define EV_SYN 0x00 //同步类
#define EV_KEY 0x01 //按键类
#define EV_REL 0x02 //相对位移类
#define EV_ABS 0x03 //绝对位移
struct input_dev { void *private; const char *name;
const char *phys;
const char *uniq;
struct input_id id; unsigned long evbit[NBITS(EV_MAX)]; //表示能产生哪类时间
unsigned long keybit[NBITS(KEY_MAX)]; //表示能产生哪些按键
unsigned long relbit[NBITS(REL_MAX)]; //表示能产生哪些相对位移事件
unsigned long absbit[NBITS(ABS_MAX)]; //表示能产生哪些绝对位移事件
unsigned long mscbit[NBITS(MSC_MAX)];
unsigned long ledbit[NBITS(LED_MAX)];
unsigned long sndbit[NBITS(SND_MAX)];
unsigned long ffbit[NBITS(FF_MAX)];
unsigned long swbit[NBITS(SW_MAX)]; unsigned int keycodemax;
unsigned int keycodesize;
void *keycode;
int (*setkeycode)(struct input_dev *dev, int scancode, int keycode);
int (*getkeycode)(struct input_dev *dev, int scancode, int *keycode); struct ff_device *ff; unsigned int repeat_key;
struct timer_list timer; int state; int sync; int abs[ABS_MAX + ];
int rep[REP_MAX + ]; unsigned long key[NBITS(KEY_MAX)];
unsigned long led[NBITS(LED_MAX)];
unsigned long snd[NBITS(SND_MAX)];
unsigned long sw[NBITS(SW_MAX)]; int absmax[ABS_MAX + ];
int absmin[ABS_MAX + ];
int absfuzz[ABS_MAX + ];
int absflat[ABS_MAX + ]; int (*open)(struct input_dev *dev);
void (*close)(struct input_dev *dev);
int (*flush)(struct input_dev *dev, struct file *file);
int (*event)(struct input_dev *dev, unsigned int type, unsigned int code, int value); struct input_handle *grab; struct mutex mutex; /* serializes open and close operations */
unsigned int users; struct class_device cdev;
union { /* temporarily so while we switching to struct device */
struct device *parent;
} dev; struct list_head h_list;
struct list_head node;
};