Re: [PATCH v2] arm64: dts: qcom: glymur: add coresight nodes

[Jie Gan <jie.gan@oss.qualcomm.com>]

On 3/23/2026 9:02 PM, Konrad Dybcio wrote:
> On 3/23/26 1:30 PM, Jie Gan wrote:
>>
>>
>> On 3/23/2026 7:05 PM, Konrad Dybcio wrote:
>>> On 3/18/26 12:42 PM, Jie Gan wrote:
>>>> Add CoreSight nodes to enable trace paths like TPDM->ETF/STM->ETF.
>>>> These devices are part of the AOSS, CDSP, QDSS, PCIe5, TraceNoc and
>>>> some small subsystems, such as GCC, IPCC, PMU and so on.
>>>>
>>>> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
>>>> ---
>>>> Changes in V2:
>>>> 1. removed two cti devices due to GFX block is down
>>>
>>> i.e. "because GPU is not yet enabled"?
>>
>> Yeah, these CTI devices have clock issue for enabling due to the GPU block is not yet enabled.
> 
> Do they need the GPU to be online, or a clock from GPU_CC, or
> maybe something else?

We need a specific debug clock inside the GPU block. The debug clock 
only can be enabled while GPU is online. Also needs AOP to support 
enable/disable the debug clock.

> 
>>>>      - cti@11c42000
>>>>      - cti@11c4b000
>>>> 2. changes two TPDM devices to static:
>>>>      - tpdm-cdsp-cmsr
>>>>      - tpdm-cdsp-cmsr2
>>>
>>> They were TPDM instances in v1. What's the reason for the change?
>>
>> These TPDMs havent clock source for accessing registers. We only need enable its ports to output trace data. So I have changed them to static-TPDM compatible.
> 
> The registers are clearly physically there. Are you saying that we
> (currently?) can't enable the clock required to access them? Or is
> there a design defect that's preventing us from doing so?

It's about hardware design. Some of the TPDM devices are designed as 
static, means we dont need access the register of the device for 
configuring. The trace data of the static TPDM is enabled by default, we 
only need enable the port of the connected TPDA device for receiving the 
data.

I have tested these devices with Jtag attached, so I didnt observe issue 
about these new devices in the CDSP block. (Jtag will provide debug 
capability for all debug devices) Also cross-checked with hardware team 
for confirming these devices are working as static.

Thanks,
Jie

> 
> Konrad
>