求教：怎么实现单个按键的长按短按功能

static void lradc1_data_function(unsigned long data)
248 {
249 volatile unsigned int reg_val;
250 static int key_pressed = -1, count = 0;
251 int delay = HZ/40;
252 reg_val = readl(KEY_BASSADDRESS+LRADC_DATA1);
253 // printk("[lkj] second lradc data1 =0x%x, s_headset_plug=%d \n", reg_val, s_headset_plug);
254 //because recorder app close this, so ....
255 writel( readl(baseaddr+0x28) | (1<<27),(baseaddr+(0x28)));
256 writel( readl(baseaddr+0x28) | (1<<29),(baseaddr+(0x28)));
257
258 if(s_first_headset_plug != 1 || s_mic_type != 1) {
259 mod_timer(&mic_data->timer, jiffies + HZ/4);
260 printk("[lkj] input key hook key return \n");
261 return ;
262 }