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SubjectRe: [PATCH v1 6/9] phy: qcom-qmp: Add support for DP in USB3+DP combo phy
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On 03/09/2020 15:41, Jonathan Marek wrote:
> On 9/3/20 8:37 AM, Dmitry Baryshkov wrote:
>> On 02/09/2020 04:01, Stephen Boyd wrote:
>>> Quoting Dmitry Baryshkov (2020-09-01 06:36:34)
>>>> With these functions I'm struggling between introducing
>>>> PHY_TYPE_DP_V3/V4 and introducing callbacks into qmp_phy_cfg. What
>>>> would
>>>> you prefer?
>>>>
>>>> What about the following struct?
>>>>
>>>> struct qmp_phy_dp_opts {
>>>>          void (*dp_aux_init)(struct qmp_phy *qphy);
>>>>          void (*dp_configure_tx)(struct qmp_phy *qphy);
>>>>          void (*dp_configure_lanes)(struct qmp_phy *qphy);
>>>> };
>>>>
>>>> I'm not sure about dp_calibrate().
>>>>
>>>
>>> Is there v4 code somewhere that I can see? Another level of indirection
>>> is always a solution, so it is probably fine. This driver is currently
>>> written with many conditionals instead of function tables so I'm not
>>> sure it fits in with the style of how things are done though. The
>>> alternative is to use an enum and call different functions?
>>
>> Downstream DP driver sources can be found here:
>> https://source.codeaurora.org/quic/la/platform/vendor/opensource/display-drivers/tree/msm/dp/dp_catalog_v420.c?h=LA.UM.8.12.r1-13900-sm8250.0
>>
>>
>> https://source.codeaurora.org/quic/la/platform/vendor/opensource/display-drivers/tree/pll/dp_pll_7nm_util.c?h=LA.UM.8.12.r1-13900-sm8250.0
>>
>>
>>>
>>> The calibrate call is there to "turn the crank" on the aux settings.  I
>>> need to cycle through the different values for that aux register so that
>>> aux can be tuned properly. The AUX channel really has another phy that
>>> needs tuning so we're sort of combining the aux and DP link phy together
>>> here by letting the calibrate call tune the AUX phy and the configure
>>> call tune the DP phy. I don't see any sort of concept of an AUX phy
>>> though so this seemed ok. Does v4 need to tune more registers?
>>
>>
>> It looks like four values are written to AUX_CFG1:
>> 0x20, 0x13, 0x23, 0x1d
>>
>
> AFAICT, it only writes 0x13 to AUX_CFG1, in dp_pll_7nm_util.c, and the
> qcom,aux-cfg1-settings in dts only has 0x13. Same for all other
> AUX_CFGn, which only have one value written. Am I missing something?

Firmware sources.


--
With best wishes
Dmitry

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