On 13/03/2026 09:26, cristian_ci wrote: > > On Tuesday, March 10th, 2026 at 21:06, Krzysztof Kozlowski <[email protected]> > wrote: > >> On 10/03/2026 18:48, cristian_ci wrote: >>> On Monday, March 9th, 2026 at 16:08, Krzysztof Kozlowski <[email protected]> >>> wrote: >>> >>>> On 09/03/2026 15:52, cristian_ci wrote: >>>>> On Sunday, March 8th, 2026 at 17:13, Krzysztof Kozlowski >>>>> <[email protected]> wrote: >>>>> >>>>>>> + vsp-supply: >>>>>>> + description: positive voltage supply for analog circuits >>>>>> >>>>>> Both are odd. Datasheet says vci, vddi, vddam and optional avdd, avee. >>>>>> >>>>>> There is no VSN and VSP. Otherwise please point the page in datasheet or >>>>>> some schematics. >>>>>> >>>>>> Best regards, >>>>>> Krzysztof >>>>>> >>>>> >>>>> I'm not sure about that. Writing panel dt-bindings has been based pretty >>>>> mostly on vendor devicetree - which also describes somehow the panel and >>>>> makes that working with the final product released to the market - so >>>>> I've to necessarily consider that. >>>>> Then, I could agree that vendor devicetree might be not compliant with >>>>> upstream rules and could possibly make mistakes with describing the >>>>> hardware, so I'd like to find a way to describe that in a more proper >>>>> way, according to upstream rules. >>>>> >>>>> That said, vendor devicetree describes lists four power supplies for >>>>> DSI: 'vdd', 'vddio', 'lab' and 'ibb' (which have the following property >>>>> names, respectively, in qcom,mdss_dsi_ctrl node: 'vdd-supply', >>>>> 'vddio-supply', 'lab-supply' and 'ibb-supply'. >>>>> Two of these are related to ds/controller (apparently, 'vddio' should >>>>> match VDDI power supply in NT35532 datasheet. >>>>> >>>>> The remaining two supplies are related to panel ('lab' and 'ibb'). These >>>>> ones are two 'external ' regulators ('external' from NT35532 >>>>> perspective), which provide power supply to display, located in the qcom >>>>> PMIC (in this case, that should be PMI8950). WRT to power supply names >>>>> described in the bindings ('vsp-supply' and 'vsn-supply') are the same as >>>>> 'lab-supply' and 'ibb-supply', just named differently in the vendor >>>>> devicetrees. >>>>> >>>>> Usage of 'vsp'/'vsn' naming for power supply properties is grounded on >>>>> they commonly being used at upstream (different panel bindings make use >>>>> of these properties), on one side, and also described on schematics of >>>>> devices with the same hardware configuration (LCD_VSN and LCD_VSP), on >>>>> the other. >>>>> >>>>> In the meantime, I've found out schematics for 'xiaomi-mido' (another >>>>> MSM8953 device) - a variant of this device is shipped with a panel also >>>>> using NT35532 IC (just like my device) - and LCD_VSN/LCD_VSP are clearly >>>>> shown there too. >>>>> >>>>> I couldn't find much more information about the display on my device and >>>>> the only resources available about that are those listed above, as of >>>>> today. In light of my reply, I ask if it is still necessary to describe, >>>>> in the bindings, power supply properties properties not used currently in >>>>> the board DTS file. >>>> >>>> Please wrap your answers so this will be possible to parse. >>>> >>>> You write bindings matching the hardware and for the hardware, not for >>>> the downstream code. You cannot add supplies which do not exist >>>> regardless what some vendor wrote somewhere >>> >>> Vendor has also described the hardware by storing information (by including >>> info >>> about panel too) directly inside the device itself (/sys/firmware/fdt). >> >> Vendor does not care about rules of DT thus puts there completely fake >> information just to make their drivers working >> . > > I'm not sure what that statement is based on in the specific case of
It's based on years of looking at vendor code. > the panel I'm actually testing. A set of clues (some of which were also > mentioned > in my first reply some days ago) point out that rimob's panel is really > supplied by > two regulators part of PMIC [1]. Not only for this reason, I do not have > enough solid reasons, after all, to consider vendor data about the panel > mounted in > this device (rimob) as not decently reliable, so I cannot ignore them, at > least. And I did not disagree that you need regulators and that vendor correctly wired two of them. The comments are about naming! I discussed of using argument of incomplete or not fully correct vendor code when the true hardware description is available. If the vendor calls them in vendor DTS "yellow-pony-supply" you are going to use that argument to write bindings? And then argue that "not sure what that statement is based on"? It's obvious - vendor code is crap. There are no VSN and VSP inputs. We already confirmed that. You claim that vendor called like that thus you can use them as well is simply not correct approach. Best regards, Krzysztof
