linux-kernel - Re: [PATCH v5 4/4] arm64: dts: ti: Add support for AM62D2-EVM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250701162504.dck3763ik6kpo7ec@bryanbrattlof.com>
Date: Tue, 1 Jul 2025 11:25:04 -0500
From: Bryan Brattlof <bb@...com>
To: Paresh Bhagat <p-bhagat@...com>
CC: <nm@...com>, <vigneshr@...com>, <praneeth@...com>, <kristo@...nel.org>,
        <robh@...nel.org>, <krzk+dt@...nel.org>, <conor+dt@...nel.org>,
        <linux-arm-kernel@...ts.infradead.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <khasim@...com>, <v-singh1@...com>,
        <afd@...com>, <devarsht@...com>, <s-vadapalli@...com>,
        <andrew@...n.ch>
Subject: Re: [PATCH v5 4/4] arm64: dts: ti: Add support for AM62D2-EVM

On June 27, 2025 thus sayeth Paresh Bhagat:
> AM62D-EVM evaluation module (EVM) is a low-cost expandable platform board
> designed for AM62D2 SoC from TI. It supports the following interfaces:
> 
> * 4 GB LPDDR4 RAM
> * x2 Gigabit Ethernet expansion connectors
> * x4 3.5mm TRS Audio Jack Line In
> * x4 3.5mm TRS Audio Jack Line Out
> * x2 Audio expansion connectors
> * x1 Type-A USB 2.0, x1 Type-C dual-role device (DRD) USB 2.0
> * x1 UHS-1 capable micro SD card slot
> * 32 GB eMMC Flash
> * 512 Mb OSPI NOR flash
> * x4 UARTs via USB 2.0-B
> * XDS110 for onboard JTAG debug using USB
> * Temperature sensors, user push buttons and LEDs
> 
> Although AM62D2 and AM62A7 differ in peripheral capabilities example
> multimedia, VPAC, and display subsystems, the core architecture remains
> same. To reduce duplication, AM62D support reuses the AM62A dtsi and the
> necessary overrides will be handled in SOC specific dtsi file and a
> board specific dts.
> 
> Add basic support for AM62D2-EVM.
> 
> Schematics Link - https://www.ti.com/lit/zip/sprcal5
> 
> Signed-off-by: Paresh Bhagat <p-bhagat@...com>
> Signed-off-by: Siddharth Vadapalli <s-vadapalli@...com>
> ---
>  arch/arm64/boot/dts/ti/Makefile          |   3 +
>  arch/arm64/boot/dts/ti/k3-am62d2-evm.dts | 599 +++++++++++++++++++++++
>  arch/arm64/boot/dts/ti/k3-am62d2.dtsi    |  25 +
>  3 files changed, 627 insertions(+)
>  create mode 100644 arch/arm64/boot/dts/ti/k3-am62d2-evm.dts
>  create mode 100644 arch/arm64/boot/dts/ti/k3-am62d2.dtsi
> 

...

> diff --git a/arch/arm64/boot/dts/ti/k3-am62d2.dtsi 
> b/arch/arm64/boot/dts/ti/k3-am62d2.dtsi
> new file mode 100644
> index 000000000000..70aeb40872a9
> --- /dev/null
> +++ b/arch/arm64/boot/dts/ti/k3-am62d2.dtsi
> @@ -0,0 +1,25 @@
> +// SPDX-License-Identifier: GPL-2.0-only OR MIT
> +/*
> + * Device Tree Source for AM62D2 SoC family in Quad core configuration
> + *
> + * TRM: https://www.ti.com/lit/pdf/sprujd4
> + *
> + * Copyright (C) 2025 Texas Instruments Incorporated - https://www.ti.com/
> + */
> +
> +/dts-v1/;
> +
> +#include "k3-am62a7.dtsi"

If we want to reuse the AM62A chassis I think we should probably reused 
the AM62AX_IOPAD() macro instead of creating a new one.

> +
> +/ {
> +	model = "Texas Instruments K3 AM62D SoC";
> +	compatible = "ti,am62d2";
> +};
> +
> +&vpu {
> +	status = "disabled";
> +};
> +
> +&e5010 {
> +	status = "disabled";
> +};

So I could be a little out of date on the style guidelines here, but my 
intuition is device trees, much like real trees, can only grow, so we 
can't inherit the am62a.dtsi and remove things.

My understanding is we have to create a full am62d.dtsi with its 
features that the am62a.dtsi can extend with the vpu{} and e5010{} nodes

~Bryan