Re: [PATCH v5 7/8] arm64: dts: apple: Add MTP DockChannel HID nodes

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential
issues to consider:
- [Low] arm64: dts: apple: undocumented mtp_mbox and mtp_dart
  compatibles on M3 SoCs
- [Low] arm64: dts: apple: MTP nodes violate ascending unit-address
  sorting order
--

commit c67685ca53359623ed7c777d5acba1746d1c1301
Author: Michael Reeves <michael.reeves077@gmail.com>

arm64: dts: apple: Add MTP DockChannel HID nodes

This commit adds disabled MTP ASC mailbox, DART IOMMU, DockChannel
mailbox, and DockChannel HID device tree nodes for Apple M2 and M3 SoCs.

> diff --git a/arch/arm64/boot/dts/apple/t6030.dtsi b/arch/arm64/boot/dts/apple/t6030.dtsi
> index 524e532830e20..15c102758097b 100644
> --- a/arch/arm64/boot/dts/apple/t6030.dtsi
> +++ b/arch/arm64/boot/dts/apple/t6030.dtsi
> @@ -492,6 +492,53 @@ wdt: watchdog@3642b0000 {
>  			interrupts = <AIC_IRQ 480 IRQ_TYPE_LEVEL_HIGH>;
>  		};
>  
> +		mtp_mbox: mbox@37a408000 {
> +			compatible = "apple,t6030-asc-mailbox", "apple,asc-mailbox-v4";
> +			reg = <0x3 0x7a408000 0x0 0x4000>;
> +			interrupt-parent = <&aic>;
> +			interrupts = <AIC_IRQ 953 IRQ_TYPE_LEVEL_HIGH>,
> +				     <AIC_IRQ 954 IRQ_TYPE_LEVEL_HIGH>,
> +				     <AIC_IRQ 955 IRQ_TYPE_LEVEL_HIGH>,
> +				     <AIC_IRQ 956 IRQ_TYPE_LEVEL_HIGH>;
> +			interrupt-names = "send-empty", "send-not-empty",
> +					  "recv-empty", "recv-not-empty";
> +			#mbox-cells = <0>;
> +			status = "disabled";
> +		};
> +
> +		mtp_dart: iommu@37a808000 {
> +			compatible = "apple,t6030-dart", "apple,t8110-dart";

[Severity: Low]
Are the M3-family compatible strings in mtp_mbox and mtp_dart documented
in the binding schemas?

Running make dtbs_check fails because apple,t6030-asc-mailbox,
apple,t6031-asc-mailbox, and apple,t8122-asc-mailbox are not listed in
Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml, and
apple,t6030-dart, apple,t6031-dart, and apple,t8122-dart are not listed in
Documentation/devicetree/bindings/iommu/apple,dart.yaml (the same applies
to t6031-die0.dtsi and t8122.dtsi below).

> +			reg = <0x3 0x7a808000 0x0 0x4000>;
> +			interrupt-parent = <&aic>;
> +			interrupts = <AIC_IRQ 937 IRQ_TYPE_LEVEL_HIGH>;
> +			#iommu-cells = <1>;
> +			status = "disabled";
> +		};
> +
> +		mtp_dockchannel: mailbox@37ab14000 {
> +			compatible = "apple,t6030-dockchannel", "apple,t8112-dockchannel";
> +			reg = <0x3 0x7ab14000 0x0 0x4000>,
> +			      <0x3 0x7ab30000 0x0 0x4000>,
> +			      <0x3 0x7ab34000 0x0 0x4000>;
> +			reg-names = "irq", "config", "data";
> +			interrupt-parent = <&aic>;
> +			interrupts = <AIC_IRQ 939 IRQ_TYPE_LEVEL_HIGH>;
> +			#mbox-cells = <0>;
> +			apple,irq-index = <1>;
> +			status = "disabled";
> +		};
> +
> +		mtp_hid: hid@37a400000 {
> +			compatible = "apple,t6030-dockchannel-hid", "apple,t8112-dockchannel-hid";
> +			reg = <0x3 0x7a400000 0x0 0x4000>,
> +			      <0x3 0x7ac00000 0x0 0x100000>;
> +			reg-names = "asc", "sram";
> +			mboxes = <&mtp_mbox>, <&mtp_dockchannel>;
> +			mbox-names = "asc", "dockchannel";
> +			iommus = <&mtp_dart 1>;
> +			status = "disabled";
> +		};
> +
>  		pinctrl_smc: pinctrl@36c820000 {

[Severity: Low]
This isn't a bug, but the new MTP nodes are out of unit-address order,
which triggers dt-check-style child-address-order warnings.

In all five files, mtp_hid (hid@...400000) is placed after mtp_mbox
(mbox@...408000), mtp_dart (iommu@...808000), and mtp_dockchannel
(mailbox@...b14000) despite having a lower unit address.  In t6030.dtsi,
the MTP block at 37a400000..37ab14000 is also placed before
pinctrl@36c820000 and pinctrl@374824000, and in t6031-die0.dtsi the MTP
block at 2ac400000..2acb14000 is placed after serial@391200000 instead of
between pinctrl@2a4820000 and i2c@391010000.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261108-b4-apple-mtp-keyboard-v5-0-e2c97b82669a@gmail.com?part=7