Re: [PATCH v3 1/2] dt-bindings: phy: qcom: Add CSI2 C-PHY/DPHY schema

[Vijay Kumar Tumati <vijay.tumati@oss.qualcomm.com>]

On 3/3/2026 2:31 PM, Dmitry Baryshkov wrote:
> On Mon, Mar 02, 2026 at 05:51:24PM -0800, Vijay Kumar Tumati wrote:
>> Hi Bryan,
>>
>> On 2/26/2026 4:34 AM, Bryan O'Donoghue wrote:
>>> +        power-domains = <&camcc CAM_CC_TITAN_TOP_GDSC>;
>> As we are cleaning up the PHY device nodes, we should consider fixing the
>> power domains as well. Although TOP GDSC is defined as a power domain, it is
>> not the power source for the PHY devices. Rather, it is the MMCX, MXC and
>> optionally MXA based on the architecture (Refer to 'Voltage rail' column for
>> PHY clocks in IPCAT). There is no
>> parent-child relationship between the TOP GDSC and these in the clock driver
>> and it was just working as the required power rails are getting enabled
>> by/for other MM devices.
> 
> Which domains are required to access CSI PHY registers?
PHY register access requires the PHY core clock, cam_top_ahb clock. So 
in my understanding, we need to trace these clocks in the topology 
backwards up until at least the RCG, and all the voltage rails powering 
these clocks will be the required power domains. Having said that, just 
register access works even if the voltage rails are configured to the 
min level, which camcc does already.
> 
>>> +
>>> +        vdda-0p8-supply = <&vreg_l2c_0p8>;
>>> +        vdda-1p2-supply = <&vreg_l1c_1p2>;
>>> +    };
>>> +
> 
Thanks,
Vijay.

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