drivers\rtc\rtc-s3c.c

s3c_rtc_init
	platform_driver_register
		s3c_rtc_probe
			rtc_device_register("s3c", &pdev->dev, &s3c_rtcops, THIS_MODULE)
				rtc_dev_prepare
					cdev_init(&rtc->char_dev, &rtc_dev_fops);
 				rtc_dev_add_device
 					cdev_add


app:    open("/dev/rtc0");
-------------------------------------------
kernel: sys_open
            rtc_dev_fops.open
            	rtc_dev_open
            	    // 根据次设备号找到以前用"rtc_device_register"注册的rtc_device
            		struct rtc_device *rtc = container_of(inode->i_cdev,struct rtc_device, char_dev);
            		const struct rtc_class_ops *ops = rtc->ops;
            		err = ops->open ? ops->open(rtc->dev.parent) : 0;
												s3c_rtc_open
app:    ioctl(fd, RTC_RD_TIME,...)
-------------------------------------------
kernel: sys_ioctl
             rtc_dev_fops.ioctl
             	 rtc_dev_ioctl
             	 		struct rtc_device *rtc = file->private_data;
             	 		rtc_read_time(rtc, &tm);
             	 			err = rtc->ops->read_time(rtc->dev.parent, tm);
             	 						s3c_rtc_gettime
             	 						
             	 		
             	 
测试RTC:
1. 修改arch\arm\plat-s3c24xx\common-smdk.c
static struct platform_device __initdata *smdk_devs[] = {
	&s3c_device_nand,
	&smdk_led4,
	&smdk_led5,
	&smdk_led6,
	&smdk_led7,
改为(在数组smdk_devs里加上s3c_device_rtc):
static struct platform_device __initdata *smdk_devs[] = {
	&s3c_device_nand,
	&smdk_led4,
	&smdk_led5,
	&smdk_led6,
	&smdk_led7,
	&s3c_device_rtc,

2. make uImage, 使用新内核启动
3. ls /dev/rtc* -l
   date /* 显示系统时间 */
   date 123015402011.30 /* 设置系统时间 date [MMDDhhmm[[CC]YY][.ss]] */
   hwclock -w           /* 把系统时间写入RTC */
   
   短电,重启,执行date