In my irq.c, there are a piece of code:

static int __init s3c2416_irq_add(struct sys_device *sysdev)
{
    printk(KERN_INFO "S3C2416: IRQ Support\n");

    s3c2416_add_sub(IRQ_LCD, s3c2416_irq_demux_lcd, &s3c2416_irq_lcd,
            IRQ_S3C2443_LCD2, IRQ_S3C2443_LCD4);

    s3c2416_add_sub(IRQ_S3C2443_DMA, s3c2416_irq_demux_dma,
            &s3c2416_irq_dma, IRQ_S3C2443_DMA0, IRQ_S3C2443_DMA5);

    s3c2416_add_sub(IRQ_S3C2443_UART3, s3c2416_irq_demux_uart3,
            &s3c2416_irq_uart3,
            IRQ_S3C2443_RX3, IRQ_S3C2443_ERR3);

    s3c2416_add_sub(IRQ_WDT, s3c2416_irq_demux_wdtac97,
            &s3c2416_irq_wdtac97,
            IRQ_S3C2443_WDT, IRQ_S3C2443_AC97);

    return 0;
}

static struct sysdev_driver s3c2416_irq_driver = {
    .add        = s3c2416_irq_add,
};