On Fri, Jun 7, 2024 at 8:40 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote: > > Kalle, > All of the devices out there need these supplies, but they are sometimes > provided by generic PCI supply and on-board regulators. Basically your > PCI adapter is not the same as QCA6390 chip on Snapdragon board. > > > > > >> Based on the discussions I have heard only Snapdragon systems who > >> require all this configuration you describe. Of course there can be > >> other systems but I have not heard about those. > >> > > > > DT is not configuration, it is description of actual hardware. It > > doesn't matter if Snapdragon systems are the only ones that actually > > *require* this description to make WLAN/BT functional upstream. The > > chipset would be the same on any PCIe board, it's just that the host > > systems wouldn't need to take care with its power sequence. But for a > > dynamic board like this, you don't need DT. > > > > Correct. > > ... > > > > >>> If your detachable board "just works" then it must be wired in a way > >>> that enables WLAN the moment it's plugged in but this doesn't happen > >>> over PCI. The chipset has a power input and GPIOs to enable each > >>> module. > >> > >> I don't know how the boards are implemented but it could be so. But from > >> host system point of view it's just a regular PCI device. > >> > > > > And you don't need DT anyway for this type of devices. > > Detechable board, like PCI adapter, derives these supplies from generic > PCI whatever-3.3v through additional regulators. All these supplies are > there - on the board. > > > > >>> Also: I doubt you need DT for your detachable board? > >> > >> Sure, I don't need DT but that's not my point. My point is why require > >> these supplies for _all_ devices having PCI id 17cb:1101 (ie. QCA6390) > >> then clearly there are such devices which don't need it? To me that's > >> bad design and, if I'm understanding correctly, prevents use of > >> qcom,ath11k-calibration-variant property. To me having the supplies > >> optional in DT is more approriate. > >> > > > > We require them because *they are physically there*. > > I understand that for all known DT QCA6390 hardware, the supplies should > be provided thus they should be required. If in the future we have > different design or we represent some pluggable PCI card, then: > 1. Probably that PCI card does not need power sequencing, thus no DT > description, > 2. If still needs power sequencing, you can always amend bindings and > un-require the supplies. > > > Best regards, > Krzysztof > Kalle, does the above answer your questions? Are these bindings good to go? Bart
