Re: [PATCH v12 3/3] arm64: dts: qcom: talos-evk: Add support for QCS615 talos evk board

[tessolveupstream]

On 04-02-2026 08:28, Dmitry Baryshkov wrote:
> On Thu, Jan 29, 2026 at 02:41:25PM +0530, tessolveupstream@xxxxxxxxx wrote:
>>
>>
>> On 16-01-2026 13:24, Dmitry Baryshkov wrote:
>>> On Fri, Jan 16, 2026 at 11:25:50AM +0530, tessolveupstream@xxxxxxxxx wrote:
>>>>
>>>>
>>>> On 15-01-2026 07:54, Jie Gan wrote:
>>>>>
>>>>>
>>>>> On 1/14/2026 6:00 PM, 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.
>>>>>>
>>>>>> Use a DTBO file, talos-evk-lvds-auo,g133han01.dtso, which defines an
>>>>>> overlay that disables HDMI and adds LVDS. The DTs file talos-evk
>>>>>> can describe the HDMI display configurations.
>>>>>>
>>>>>> 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
>>>>>> - SN65DSI84ZXHR DSI-to-LVDS bridge
>>>>>> - Wi-Fi/BT
>>>>>>
>>>
>>>>>> +
>>>>>> +&usb_1 {
>>>>>> +    status = "okay";
>>>>>> +};
>>>>>> +
>>>>>> +&usb_1_dwc3 {
>>>>>> +    dr_mode = "host";
>>>>>> +};
>>>>>> +
>>>>>> +&usb_hsphy_1 {
>>>>>> +    vdd-supply = <&vreg_l5a>;
>>>>>> +    vdda-pll-supply = <&vreg_l12a>;
>>>>>> +    vdda-phy-dpdm-supply = <&vreg_l13a>;
>>>>>> +
>>>>>> +    status = "okay";
>>>>>> +};
>>>>>> +
>>>>>> +&usb_2 {
>>>>>> +    status = "okay";
>>>>>> +};
>>>>>> +
>>>>>> +&usb_2_dwc3 {
>>>>>> +    dr_mode = "host";
>>>>>> +};
>>>>>
>>>>> Both usb devices have been configured to host mode, do we need adb?
>>>>> The adb only work with usb peripheral mode.
>>>>>
>>>>
>>>> This topic was discussed previously, and the fix was implemented 
>>>> based on that discussion.
>>>> For reference, I’m sharing the earlier communication in the 
>>>> links below.
>>>>
>>>> https://lore.kernel.org/all/qq4aak33bn3mqxd2edu6zgkkshby63mmitg7zqkly2rj4c2lh7@4s7sndb7e2jr/T/#meaa464a4e6992b36b5d8d41ddc691ee4ea36b1ce
>>>>
>>>> https://lore.kernel.org/all/20251014120223.1914790-1-tessolveupstream@xxxxxxxxx/T/#t
>>>
>>> Neither of these links is relevant to the question.
>>>
>>
>> In our hardware design, the USB0 controller is a USB 3.0-capable 
>> controller whose high‑speed (HS) differential lines are routed through 
>> a mechanical switch.
>>
>> a) During EDL (flashing) mode:
>>    The HS lines are explicitly routed to the Micro‑USB port. 
>>    This allows the SoC to enter "device mode" for firmware flashing.
>>
>> b) After EDL completes (normal operation):
>>    The mechanical switch is driven to route the HS signals to the on‑
>>    board USB 3.0 hub.
>>    The hub connects to four Type-A ports, all designed for host mode 
>>    only.
>>    The Micro-USB connector is now electrically disconnected.
>>
>> Why host-only mode: Once the switch routes to the hub, there's no 
>> electrical path back to the Micro-USB port. The USB controller can 
>> only talk to the hub and its downstream Type-A ports, which are wired 
>> for host mode only. Device mode is physically impossible in this 
>> configuration.
>> Therefore, USB0 must be configured as host-only in the device tree, 
>> since device mode cannot work after the system boots.
>>  
>> The USB1 controller supports USB 2.0 and has its data lines directly 
>> routed to a Type-A connector. This hardware design restricts the 
>> controller to host-only operation, preventing any peripheral/device 
>> mode functionality.
> 
> Please add a comment regarding EDL-mode DIP switch and describe the
> onboard HUB in the DT. Additionally consider adding the USB-peripheral
> overlay, corresponding to the EDL-mode configuration as some labs will
> not trigger the DIP switch at runtime and settle with the
> peripheral-only setting for the USB controller.
> 

Okay, got it. Will take care in the next patch.