浅析linux下键盘设备工作和注册流程

浅析linux下键盘设备工作和注册流程
【浅析linux下鼠标驱动的实现】
 input_init()=>
=>
class_register(&input_class);注册input类
input_proc_init();创建proc下的目录和文件
register_chrdev(INPUT_MAJOR, "input", &input_fops);注册驱动程序到cdev_map上,以待驱动设备.
drivers\input\keyboard\pxa3xx_keypad.c为我们的keyboard设备,
pxa3xx_keypad_probe=>
request_irq(IRQ_ENHROT, &enhanced_rotary_interrupt,
            IRQF_DISABLED, "Enhanced Rotary", (void *)keypad);注册快捷键中断
request_irq(IRQ_KEYPAD, pxa3xx_keypad_interrupt, IRQF_DISABLED,pdev->name, keypad);注册中断
static irqreturn_t pxa3xx_keypad_interrupt(int irq, void *dev_id)
{
    struct pxa3xx_keypad *keypad = dev_id;
    uint32_t kpc = keypad_readl(KPC);
    if (kpc & KPC_MI)
        pxa3xx_keypad_scan_matrix(keypad);
    if (kpc & KPC_DI)
        pxa3xx_keypad_scan_direct(keypad);
    return IRQ_HANDLED;
}
在irq中如果读到了key,那么会直接调用
input_report_key(keypad->input_dev,lookup_matrix_keycode(keypad, row, col),
                new_state[col] & (1 << row));
static inline unsigned int lookup_matrix_keycode(
        struct pxa3xx_keypad *keypad, int row, int col)
{
    return keypad->matrix_keycodes[(row << 3) + col];
}
input_report_key(struct input_dev *dev, unsigned int code, int value)
dev为input_dev设备,我们的4*4键盘
code为标准PC键盘码值
value为按键动作,为1表示键盘按下,为0表示按键抬起
static inline void input_report_key(struct input_dev *dev, unsigned int code, int value)
{
    input_event(dev, EV_KEY, code, !!value);
}
void inp