RTC is not updating in RZ/G2L. RTC has no clock.

Dear Team,

                In our custom board based on rzg2l RTC is not updating as it does not produce 32768 khz which it is supposed to do. It sets time but not updating. But in the development board we found that there is clock and it is updating. We are using the same pmic raa215300 but in the custom board is on/off version pmic ie, RAA215300A2GNP#HA1 and in evaluation module RAA215300A2GNP#HA0 Long Push button type. These are bascally same pmic  other than on/off vs long push button. it is connected to i2c3 as shown in below.

&i2c3 {
	pinctrl-0 = <&i2c3_pins>;
	pinctrl-names = "default";
	clock-frequency = <400000>;

	status = "okay";

	pmic: raa215300@12 {
		compatible = "renesas,raa215300";
		reg = <0x12>;

	rtc: isl1208@6f {
		compatible = "isil,isl1208";
		reg = <0x6f>;

why  clock is updating in evaluation module but not in custom board? Please help

  • So same configuration as evk? Identical i2c configuration?


    dmesg | grep -ri rtc

    i2cdetect -y 3


    hwclock -w -v

  • Already done it  but the rtc sets time but it is not updating. Please look at below.

    But in evaluation board it is updating.  Why the time is not updating in custom board?

  • In your case  RTCF is set.

    This bit is set to a “1” after a total power failure. This is a read
    only bit that is set by hardware (ISL1208 internally) when the
    device powers up after having lost all power to the device (both
    VDD and VBAT go to 0V). The bit is set regardless of whether
    VDD or VBAT is applied first. The loss of only one of the
    supplies does not set the RTCF bit to “1”. On power-up after a
    total power failure, all registers are set to their default states
    and the clock will not increment until at least one byte is written
    to the clock register. The first valid write to the RTC section
    after a complete power failure resets the RTCF bit to “0”
    (writing one byte is sufficient).

    rtc_time : 12:18:54
    rtc_date : 2023-09-22
    alrm_time : 00:00:00
    alrm_date : 2023-09-23
    alarm_IRQ : no
    alrm_pending : no
    update IRQ enabled : no
    periodic IRQ enabled : no
    periodic IRQ frequency : 1
    max user IRQ frequency : 64
    24hr : yes
    status_reg : XTOSCB (0x40)
    batt_status : okay
    digital_trim : 0 ppm
    analog_trim : 12.50 pF
    user_data : 0x0000

  • Thanks for your reply

                    I applied the setting as you told me and it is not updating the clock . Following is the image of rtc after applying the settings as you told me. The 0x41 is not changing to 0x40.

    Also below is the schematic of our pmic setup in our board.


  • Unbind RTC:

    echo -n "3-006f" > /sys/bus/i2c/drivers/rtc-isl1208/unbind

    Get SR:

    i2cget -y 3 0x6f 0x7

    Set one of the clock registers:

    i2cset -y 3 0x6f 0x6 0

    Get SR again:

    i2cget -y 3 0x6f 0x7

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