linux-kernel - Re: [PATCH v7 2/2] arm64: dts: qcom: talos-evk: Add support for QCS615 talos evk board

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] [day] [month] [year] [list]
Message-ID: <7dbd8d7a-73ef-4285-aaf3-f767081b0766@gmail.com>
Date: Sat, 29 Nov 2025 17:32:05 +0530
From: tessolveupstream@...il.com
To: Bjorn Andersson <andersson@...nel.org>
Cc: konradybcio@...nel.org, robh@...nel.org, krzk+dt@...nel.org,
 conor+dt@...nel.org, linux-arm-msm@...r.kernel.org,
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 2/2] arm64: dts: qcom: talos-evk: Add support for
 QCS615 talos evk board



On 18-11-2025 21:00, Bjorn Andersson wrote:
> On Tue, Nov 18, 2025 at 06:38:14PM +0530, Sudarshan Shetty wrote:
>> Add the device tree for the QCS615-based Talos EVK platform. The
>> platform is composed of a System-on-Module following the SMARC
>> standard, and a Carrier Board.
>>
>> The Carrier Board supports several display configurations, HDMI and
>> LVDS. Both configurations use the same base hardware, with the display
>> selection controlled by a DIP switch.
>>
>> To avoid duplication, use an include file, talos-evk-cb.dtsi, which
>> defines the interfaces and peripherals common to both display
>> variants. Two additional DTs (e.g. talos-evk and talos-evk-lvds)
>> can describe the selected display configuration.
>>
>> The initial device tree includes support for:
>> - CPU and memory
>> - UART
>> - GPIOs
>> - Regulators
>> - PMIC
>> - Early console
>> - AT24MAC602 EEPROM
>> - MCP2515 SPI to CAN
>> - ADV7535 DSI-to-HDMI bridge
>> - DisplayPort interface
>>
>> Signed-off-by: Sudarshan Shetty <tessolveupstream@...il.com>
>> ---
>>  arch/arm64/boot/dts/qcom/Makefile           |   1 +
>>  arch/arm64/boot/dts/qcom/talos-evk-cb.dtsi  |  56 +++
>>  arch/arm64/boot/dts/qcom/talos-evk-som.dtsi | 447 ++++++++++++++++++++
>>  arch/arm64/boot/dts/qcom/talos-evk.dts      |  94 ++++
>>  4 files changed, 598 insertions(+)
>>  create mode 100644 arch/arm64/boot/dts/qcom/talos-evk-cb.dtsi
>>  create mode 100644 arch/arm64/boot/dts/qcom/talos-evk-som.dtsi
>>  create mode 100644 arch/arm64/boot/dts/qcom/talos-evk.dts
>>
>> diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
>> index 5b52f9e4e5f3..282d744acd73 100644
>> --- a/arch/arm64/boot/dts/qcom/Makefile
>> +++ b/arch/arm64/boot/dts/qcom/Makefile
>> @@ -305,6 +305,7 @@ dtb-$(CONFIG_ARCH_QCOM)	+= sm8650-mtp.dtb
>>  dtb-$(CONFIG_ARCH_QCOM)	+= sm8650-qrd.dtb
>>  dtb-$(CONFIG_ARCH_QCOM)	+= sm8750-mtp.dtb
>>  dtb-$(CONFIG_ARCH_QCOM)	+= sm8750-qrd.dtb
>> +dtb-$(CONFIG_ARCH_QCOM)	+= talos-evk.dtb
>>  x1e001de-devkit-el2-dtbs	:= x1e001de-devkit.dtb x1-el2.dtbo
>>  dtb-$(CONFIG_ARCH_QCOM)	+= x1e001de-devkit.dtb x1e001de-devkit-el2.dtb
>>  x1e78100-lenovo-thinkpad-t14s-el2-dtbs	:= x1e78100-lenovo-thinkpad-t14s.dtb x1-el2.dtbo
>> diff --git a/arch/arm64/boot/dts/qcom/talos-evk-cb.dtsi b/arch/arm64/boot/dts/qcom/talos-evk-cb.dtsi
> 
> I might have missed where you replied to any of my questions. But I
> still believe this file represents the Talos EVK - that is, the "Talos
> SOM" + the "Talos EVK Carrier board".
> 

Yes. This file represents "Talos SOM" + the "Talos EVK Carrier board".
>> new file mode 100644
>> index 000000000000..81d15ee4f366
>> --- /dev/null
>> +++ b/arch/arm64/boot/dts/qcom/talos-evk-cb.dtsi
>> @@ -0,0 +1,55 @@
>> +// SPDX-License-Identifier: BSD-3-Clause
>> +/*
>> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
>> + */
>> +/dts-v1/;
>> +
>> +#include "talos-evk-som.dtsi"
> 
> Here this file stops being just a definition of the "carrier board",
> it's now the whole EVK.
> 
> As such, this file should be called "talos-evk".
> 
> We now have two options:
> 
> 1) talos-som.dtsi + talos-evk.dts + talos-evk-lvds-auo,g133han01.dtso
> 
>    We describe the SOM, we describe the "standard configuration" of the
>    EVK, and we have an overlay example that disabled the HDMI portions
>    and adds LVDS and the specific panel.
> 
> 
> 2) talos-som.dtsi + talos-evk.dtsi + talos-evk-hdmi.dts +
>    talos-evk-lvds.dts + talos-evk-lvds-auo,g133han01.dtso
> 
>    We avoid describing HDMI, just to remove it again in the overlay.
> 
> 
> #2 would scale better if we have a lot of these boards, but unless we
> expect a lot of different boards/combinations I don't think there's much
> value in it.
> 
> 
> Please let me know if my assumptions are wrong, but for now I think #1
> is the correct choice.
> 
> In either case, you should include the LVDS support in this same patch
> series, so that we have all the parts that we're discussing in front of
> us.
> 

Will proceed with option #1 by creating three files, i.e., 
talos-som.dtsi + talos-evk.dts + talos-evk-lvds-auo,g133han01.dtso
The file "talos-evk-lvds-auo,g133han01.dtso" include the overlay to 
disable HDMI and adds the LVDS-related on top of the base EVK 
DTS file.
>> +
>> +/ {
>> +	model = "Qualcomm QCS615 IQ 615 EVK";
>> +	compatible = "qcom,talos-evk", "qcom,qcs615", "qcom,sm6150";
>> +	chassis-type = "embedded";
>> +
> [..]
>> diff --git a/arch/arm64/boot/dts/qcom/talos-evk-som.dtsi b/arch/arm64/boot/dts/qcom/talos-evk-som.dtsi
> [..]
>> +&mdss_dp0_out {
>> +	link-frequencies = /bits/ 64 <1620000000 2700000000 5400000000>;
>> +	remote-endpoint = <&dp0_connector_in>;
> 
> Don't we need/want a data-lanes property here as well?
>

Not required. Data-lane property is already defined in "talos.dtsi". >> +};
>> +
> 
> The rest of the patch looks good to me.
> 
> Regards,
> Bjorn