Re: [PATCH] arm64: dts: rockchip: Enable i2c2 on Orange Pi 3B

[Michael Opdenacker]

Hi Jonas

Thanks for the review!

On 11/26/25 09:40, Jonas Karlman wrote:
> Hi Michael,
>
> On 11/20/2025 8:00 PM, Michael Opdenacker wrote:
> > Enable the "i2c2" bus on header pins 3 (I2C_SDA_M1)
> > and 5 (I2C2_SCL_M1) of the Orange Pi 3B board.
> >
> > As documented on http://www.orangepi.org/img/pi3b/0719-pi3b-19.png
> > such pins are the only ones offering I2C functionality
> > without conflicting with other SoC blocks.
> This is strictly not true, these pins are by default used as GPIO, this
> patch change them to use the I2C2 func, something that should normally
> be enabled in an overlay.
>
> Functions for these pins:
>
> 	func 0		func 1
>
> 	GPIO4_B4_d	I2C2_SDA_M1
> 	GPIO4_B5_d	I2C2_SCL_M1


Correct. My idea was that GPIOs are easy to get on other pins, and I 
found that I2C2 on such pins would be a convenient default.

> > Signed-off-by: Michael Opdenacker <michael.opdenacker@xxxxxxxxxxxxxx>
> > ---
> >   arch/arm64/boot/dts/rockchip/rk3566-orangepi-3b.dtsi | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git a/arch/arm64/boot/dts/rockchip/rk3566-orangepi-3b.dtsi b/arch/arm64/boot/dts/rockchip/rk3566-orangepi-3b.dtsi
> > index d539570f531e..e2f0ccc6dbe7 100644
> > --- a/arch/arm64/boot/dts/rockchip/rk3566-orangepi-3b.dtsi
> > +++ b/arch/arm64/boot/dts/rockchip/rk3566-orangepi-3b.dtsi
> > @@ -435,6 +435,11 @@ regulator-state-mem {
> >   	};
> >   };
> >   
> > +&i2c2 {
> > +	pinctrl-0 = <&i2c2m1_xfer>;
> pinctrl-names should also be added here.


Actually, the "pinctrl-names" property is already available in the 
definition of i2c2. That's why I didn't add it again.

> > +	status = "okay";
> As mentioned above, this should be enabled in an DT overlay not in the
> board DT.

I don't mind if my patch is removed, no hard feelings :)

BTW, is there a convenient location for sharing overlays like these? 
Some overlays are sometimes tricky to develop, and sharing them with 
others is useful for the community.  I guess the question was asked 
before, but I don't know its answer :)

Thanks again
Cheers
Michael.

--
Michael Opdenacker
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