[PATCH 0/8] Add support for Qualcomm SA8155-ADP board

[Konrad Dybcio]

On 3/4/24 16:51, Volodymyr Babchuk wrote:
> 
> Hi Stephan,
> 
> Stephan Gerhold <stephan at gerhold.net> writes:
> 
>> On Fri, Mar 01, 2024 at 06:25:39PM +0000, Volodymyr Babchuk wrote:
>>> Caleb Connolly <caleb.connolly at linaro.org> writes:
>>>> On 29/02/2024 14:21, Volodymyr Babchuk wrote:
>>>>> This patch series adds support for Qualcomm SA8155-ADP development
>>>>> board. Main motivation for this series is to allow running
>>>>> virtualization software on this board and U-Boot is a good way to
>>>>> break Qualcomm's boot chain at EL2 with more convenient ways for
>>>>> uploading and running the code. With this patches applied it is
>>>>> possible to upload and run Xen on this board. KVM probably should work
>>>>> too.
>>>>
>>>> This is really cool! I've experimented with this on SDM845 and SM8250
>>>> but never really did anything with it... I'd love to take a look at your
>>>> Xen branch?
>>>
>>> Honestly, there is nothing to look at right now. I just implemented
>>> early printk serial driver for the qcom, made hacks to the device tree
>>> and trying to boot Dom0. I already expecting issues with the GPU,
>>> because it has own SMMU without virtualization support and Xen already
>>> complains about it. So I had to remove it from the DTS for a time being.
>>>
>>
>> Did you enable all the clocks/power domains/etc for the GPU SMMU? If I
>> remember correctly it is off by default and all registers read as
>> zeroes. The SMMU driver could easily get confused about the capabilities
>> of the SMMU (e.g. the stage 2/virtualization support) if all the ID
>> registers read as zeroes.
> 
> Ah, this is a great idea, thanks. I tried a quick test by enabling only
> clocks that are provided by GCC, but looks like I need to enable GPUCC
> clocks as well. So I need to write a driver for GPUCC or at least
> figure which registers to write with a debugger. I'll try this later.

You'll probably also need to enable the CX GDSC (not sure about the
order, probably GDSC and then clocks)

Konrad