[PATCH v3] ARM: dts: bcm2711-rpi-cm4-io: Add rtc on a pinctrl-muxed i2c bus

[Jean-Michel Hautbois]

Hi Uwe,

Thanks for the patch !

On 31/12/2021 12:51, Uwe Kleine-König wrote:
> The cm4-io board comes with an PCF85063. Add it to the device tree to make
> it usable. The i2c0 bus can use two different pinmux settings to use
> different pins. To keep the bus appearing on the usual pin pair (gpio0 +
> gpio1) use a pinctrl-muxed setting as the vendor dts does.
> 
> Note that if you modified the dts before to add devices to the i2c bus
> appearing on pins gpio0 + gpio1 (either directly in the dts or using an
> overlay), you have to put these into the i2c at 0 node introduced here now.
> 
> Reviewed-by: Maxime Ripard <maxime at cerno.tech>
> Signed-off-by: Uwe Kleine-König <uwe at kleine-koenig.org>
> ---
> Hello,
> 
> changes since v2 (20211216212948.nrfmm4jpbhoknfr5 at pengutronix.de):
> 
>   - add Maxime's R-b tag
>   - change the commit log wording to say vendor dts instead of upstream
>     dts
>   - Add a paragraph to the commit log about breakage this commits
>     introduces.
> 
> Best regards
> Uwe
> 
>   arch/arm/boot/dts/bcm2711-rpi-cm4-io.dts | 35 ++++++++++++++++++++++++
>   1 file changed, 35 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/bcm2711-rpi-cm4-io.dts b/arch/arm/boot/dts/bcm2711-rpi-cm4-io.dts
> index 19600b629be5..5ddad146b541 100644
> --- a/arch/arm/boot/dts/bcm2711-rpi-cm4-io.dts
> +++ b/arch/arm/boot/dts/bcm2711-rpi-cm4-io.dts
> @@ -18,6 +18,41 @@ led-pwr {
>   			linux,default-trigger = "default-on";
>   		};
>   	};
> +
> +	i2c0mux {
> +		compatible = "i2c-mux-pinctrl";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		i2c-parent = <&i2c0>;
> +
> +		pinctrl-names = "i2c0", "i2c0-vc";
> +		pinctrl-0 = <&i2c0_gpio0>;
> +		pinctrl-1 = <&i2c0_gpio44>;
> +
> +		i2c at 0 {
> +			reg = <0>;
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +		};
> +
> +		i2c at 1 {
> +			reg = <1>;
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			rtc at 51 {
> +				/* Attention: An alarm resets the machine */
> +				compatible = "nxp,pcf85063";
> +				reg = <0x51>;
> +			};
> +		};
> +	};
> +};

This is also needed for camera and display support.
I tested it successfully with imx219 + unicam on mainline.

> +
> +&i2c0 {
> +	/delete-property/ pinctrl-names;
> +	/delete-property/ pinctrl-0;
>   };
>   
>   &ddc0 {
> 
> base-commit: fc74e0a40e4f9fd0468e34045b0c45bba11dcbb2
>