On 18/02/2024 16:29, Samuel Holland wrote: > Hi Krzysztof, > > On 2024-02-17 3:00 AM, Krzysztof Kozlowski wrote: >> On 16/02/2024 01:08, Samuel Holland wrote: >>> The SiFive Composable Cache controller contains an optional PMU with a >>> configurable number of event counters. Document a property which >> >> Configurable in what context? By chip designers or by OS? Why this >> cannot be deduced from the compatible? > > This parameter is configurable by the chip designers. > > The information certainly can be deduced from the SoC-specific compatible > string, but doing so makes the driver only work on that specific list of SoCs. Usually that's exactly what's expected, so why here usual approach is wrong? > When provided via a property, the driver can work without changes on any SoC > that uses this IP block. (None of the SoCs currently listed in the binding Sorry, properties are not a work-around for missing compatibles. > contain a PMU, so there is no backward compatibility concern with adding the new > property.) > > My understanding of the purpose of the SoC-specific compatible string is to > handle eventualities (silicon bugs, integration quirks, etc.), not to > intentionally limit the driver to a narrow list of hardware. Depends what is the hardware. For most of licensed blocks, the final design is the hardware so equals to its compatible. Best regards, Krzysztof
