On 16/10/2023 06:31, Krzysztof Kozlowski wrote: > On 15/10/2023 23:11, Caleb Connolly wrote: >> This new property allows devices to specify some register values which >> are missing on units with third party replacement displays. These >> displays use unofficial touch ICs which only implement a subset of the >> RMI4 specification. >> >> Signed-off-by: Caleb Connolly <caleb.connolly@xxxxxxxxxx> >> --- >> To: "Jason A. Donenfeld" <Jason@xxxxxxxxx> >> To: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx> >> To: Rob Herring <robh+dt@xxxxxxxxxx> >> To: Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx> >> To: Conor Dooley <conor+dt@xxxxxxxxxx> >> Cc: devicetree@xxxxxxxxxxxxxxx >> --- >> Documentation/devicetree/bindings/input/syna,rmi4.yaml | 15 +++++++++++++++ >> 1 file changed, 15 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/input/syna,rmi4.yaml b/Documentation/devicetree/bindings/input/syna,rmi4.yaml >> index 4d4e1a8e36be..1f4a2179e4d3 100644 >> --- a/Documentation/devicetree/bindings/input/syna,rmi4.yaml >> +++ b/Documentation/devicetree/bindings/input/syna,rmi4.yaml >> @@ -49,6 +49,21 @@ properties: >> description: >> Delay to wait after powering on the device. >> >> + syna,pdt-fallback-desc: >> + $ref: /schemas/types.yaml#/definitions/uint8-matrix >> + description: >> + An array of pairs of function number and version. These are used > > You nicely explained what is expected to be here, but what is the > purpose of adding this property? Please add it to the description. This property is to provide some "expected" register values to handle hardware where registers that should have values are empty (MCUs running dodgy firmware pretending to be an rmi4 capable controller). > >> + on some devices with replacement displays that use unofficial touch >> + controllers. These controllers do report the properties of their Page >> + Descriptor Table (PDT) entries, but leave the function_number and >> + function_version registers blank. These values should match exactly >> + the 5th and 4th bytes of each PDT entry from the original display's >> + touch controller. >> + items: >> + items: >> + - description: The 5th byte of the PDT entry >> + - description: The 4th byte of the PDT entry > > Missing constraints on outer level: > maxItems: 1 There can be (technically) an arbitrary number of pairs here, it should align with the number of Page Descriptor Tables supported by the device. This is basically meant to done on a best-effort basis. The OnePlus 6 has 3 pairs here. I'll give another pass at the description and see if I can explain this better heh. > > > > Best regards, > Krzysztof > -- // Caleb (they/them)
