AM625: 外部RTC出错

你好

  我使用PCF8563为AM625提供外部RTC，使用了I2C0，设备树配置如下

main_i2c0_pins_default: main-i2c0-pins-default {
		pinctrl-single,pins = <
			AM62X_IOPAD(0x1e0, PIN_INPUT_PULLUP, 0) /* (B16) I2C0_SCL */
			AM62X_IOPAD(0x1e4, PIN_INPUT_PULLUP, 0) /* (A16) I2C0_SDA */
		>;
	};
	
&main_i2c0 {
        status = "okay";
        pinctrl-names = "default";
        pinctrl-0 = <&main_i2c0_pins_default>;
        clock-frequency = <400000>;

        pcf8563:rtc@51{
                compatible = "nxp,pcf8563";
                reg = <0x51>;
                status = "okay";
        };
};

我想使用hwclock来查看时，会一直提示     hwclock: ioctl(RTC_RD_TIME) to /dev/rtc0 to read the time failed: Invalid argument

内核启动时提示：
[ 7.811184] rtc-pcf8563 2-0051: registered as rtc0
[ 7.816563] rtc-pcf8563 2-0051: hctosys: unable to read the hardware clock

尝试使用hwclock -w 写入，但写入后还是如此的错误。