Hardware clock on the Pioneer

Hardware clock on the Pioneer

[Michael Orlitzky]

Hello, I finally have the upstream kernel running on my Pioneer Box,
and I notice that the hardware clock is not enabled. I've patched this
in my own kernel (sg2042-milkv-pioneer.dts) by enabling i2c0, defining
the RTC,

  &i2c0 {
    pinctrl-0 = <&i2c0_cfg>;
    pinctrl-names = "default";
    status = "okay";

      rtc: rtc@68 {
        compatible = "dallas,ds1307";
        reg = <0x68>;
    };
  };

and copying the pinctrl bits from i2c1:

  i2c0_cfg: i2c0-cfg {
    i2c0-pins {
      pinmux = <PINMUX(PIN_IIC0_SDA, 0)>,
               <PINMUX(PIN_IIC0_SCL, 0)>;
      bias-pull-up;
      drive-strength-microamp = <26800>;
      input-schmitt-enable;
    };
  };

It seems to work:

  $ sudo hwclock --show
  2025-12-30 17:54:05.093606-05:00

Is there a reason not to do this? The sophgo upstream status page says
that the RTC is "Low priority, may not be needed." But if the above is
OK, I will submit a patch for it.

Re: Hardware clock on the Pioneer

[Chen Wang]

Hello~

On 12/31/2025 6:56 AM, Michael Orlitzky wrote:
> Hello, I finally have the upstream kernel running on my Pioneer Box,
> and I notice that the hardware clock is not enabled. I've patched this
> in my own kernel (sg2042-milkv-pioneer.dts) by enabling i2c0, defining
> the RTC,
>
>    &i2c0 {
>      pinctrl-0 = <&i2c0_cfg>;
>      pinctrl-names = "default";
>      status = "okay";
>
>        rtc: rtc@68 {
>          compatible = "dallas,ds1307";
>          reg = <0x68>;
>      };
>    };
>
> and copying the pinctrl bits from i2c1:
>
>    i2c0_cfg: i2c0-cfg {
>      i2c0-pins {
>        pinmux = <PINMUX(PIN_IIC0_SDA, 0)>,
>                 <PINMUX(PIN_IIC0_SCL, 0)>;
>        bias-pull-up;
>        drive-strength-microamp = <26800>;
>        input-schmitt-enable;
>      };
>    };
>
> It seems to work:
>
>    $ sudo hwclock --show
>    2025-12-30 17:54:05.093606-05:00
It looks good to me.
>
> Is there a reason not to do this? The sophgo upstream status page says
> that the RTC is "Low priority, may not be needed." But if the above is
> OK, I will submit a patch for it.

I don't quite remember why I initially said it wasn't needed; perhaps I 
just thought it wouldn't significantly impact the main functionality, so 
I wasn't in a rush to implement it. Later, I got busy with other things 
and didn't have time to work on it.

Therefore, I think it should be ok for you to submit a patch to the 
upstream.

BTW, I saw a similar implementation in the sophgo code repository [1], 
but it doesn't quite conform to the upstream standard, while your 
approach is better.

Link to: 
https://github.com/sophgo/linux-riscv/blob/sg2042-rel-6.1.31/arch/riscv/boot/dts/sophgo/mango-milkv-pioneer.dts#L12 
[1]

Thanks,

Chen