Messages in this thread | | | Date | Thu, 25 Jan 2024 17:36:06 +0100 | Subject | Re: [PATCH 0/3] phy: qcom: edp: Add support for DT phy mode configuration | From | Konrad Dybcio <> |
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On 1/15/24 10:52, Abel Vesa wrote: > On 24-01-03 14:42:49, Konrad Dybcio wrote: >> On 21.12.2023 17:27, Dmitry Baryshkov wrote: >>> On Tue, 19 Dec 2023 at 22:55, Abel Vesa <abel.vesa@linaro.org> wrote: >>>> >>>> Until now, all platform that supported both eDP and DP had different >>>> compatibles for each mode. Using different compatibles for basically >>>> the same IP block but for a different configuration is bad way all >>>> around. There is a new compute platform from Qualcomm that supports >>>> both eDP and DP with the same PHY. So instead of following the old >>>> method, we should allow the mode to be configured from devicetree. >>>> >>>> There has been an off-list discussion on what would be the right way >>>> to pass on the PHY mode information to the driver and it has been >>>> concluded that phy-cells is the way to go. This means that basically >>>> the controller will pass another value (that is, the PHY type) to >>>> its 'phys' DT property. >>>> >>>> For this, we need both the bindings value and the PHY mode value to be >>>> added as well. >>>> >>>> The controller part will follow shortly. But for now, lets see where >>>> this is going. >>>> >>>> There has been another attempt at this here: >>>> https://lore.kernel.org/all/20231122-phy-qualcomm-edp-x1e80100-v3-3-576fc4e9559d@linaro.org/ >>>> >>>> Compared to that version, this one uses the phy-cells method and drops >>>> the X1E80100 support. The X1E80100 support will be a separate patchset. >>> >>> After several back and forth discussions, I think that this approach >>> is not correct and not that easy to extend. Instead I'd like to >>> suggest adding a property to the DP controller, which enables eDP >>> behaviour (and thus makes DP driver call phy_set_mode()). Something >>> like this: >>> dp: displayport-controller@ae0000 { >>> compatible = "qcom,sm8000-dp"; >>> /* reg, interrupts, etc */ >>> edp-interface; >>> /* or simpler */ >>> is-edp; >>> }; >>> >>> What do you think? >> >> Please excuse my alzheimer, but why did we not go with phy-type after >> the last discussion? > > phy-type would be a property of the phy. That way we would need pass > the mode to the controller. So it was concluded that passing that > information from the controller via phy_set_mode is more straightforward.
Eeh, reluctantly, I'm gonna say yes. It's not the prettiest solution, but none of the ones I can think of seem much better.
Konrad
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