On 28/07/2022 11:54, Jerome Brunet wrote: > > On Thu 28 Jul 2022 at 11:48, Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: > >> On 28/07/2022 11:09, Jerome Brunet wrote: >>> >>> On Thu 28 Jul 2022 at 11:02, Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: >>> >>>> On 28/07/2022 10:50, Jerome Brunet wrote: >>>>> >>>>> On Thu 28 Jul 2022 at 10:41, Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: >>>>> >>>>>> On 28/07/2022 07:42, Yu Tu wrote: >>> [...] >>>>>>> +/* >>>>>>> + * CLKID index values >>>>>>> + */ >>>>>>> + >>>>>>> +#define CLKID_FIXED_PLL 1 >>>>>>> +#define CLKID_FCLK_DIV2 3 >>>>>>> +#define CLKID_FCLK_DIV3 5 >>>>>>> +#define CLKID_FCLK_DIV4 7 >>>>>>> +#define CLKID_FCLK_DIV5 9 >>>>>>> +#define CLKID_FCLK_DIV7 11 >>>>>> >>>>>> Why these aren't continuous? IDs are expected to be incremented by 1. >>>>>> >>>>> >>>>> All clocks have IDs, it is one big table in the driver, but we are not exposing them all. >>>>> For example, with composite 'mux / div / gate' assembly, we usually need >>>>> only the leaf. >>>> >>>> I understand you do not expose them all, but that is not the reason to >>>> increment ID by 2 or 3... Otherwise these are not IDs and you are not >>>> expected to put register offsets into the bindings (you do not bindings >>>> in such case). >>> >>> Why is it not an IDs if it not continuous in the bindings ? >>> >>> If there is technical reason, we'll probably end up exposing everything. It >>> would not be a dramatic change. I asked for this over v1 because we have >>> done that is the past and I think it makes sense. >>> >>> I'm happy to be convinced to do things differently. Just looking for the >>> technical reason that require contiuous exposed IDs. >>> >>> The other IDs exists, but we do not expose them as bindings. >>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clk/meson/gxbb.h#n125 >> >> https://lore.kernel.org/linux-devicetree/CAK8P3a1APzs74YTcZ=m43G3zrmwJZKcYSTvV5eDDQX-37UY7Tw@xxxxxxxxxxxxxx/ >> >> https://lore.kernel.org/linux-devicetree/CAK8P3a0fDJQvGLEtG0fxLkG08Fh9V7LEMPsx4AaS+2Ldo_xWxw@xxxxxxxxxxxxxx/ >> >> https://lore.kernel.org/linux-devicetree/b60f5fd2-dc48-9375-da1c-ffcfe8292683@xxxxxxxxxx/ >> >> The IDs are abstract numbers, where the number does not matter because >> it is not tied to driver implementation or device programming model. The >> driver maps ID to respective clock. >> >> Using some meaningful numbers as these IDs, means you tied bindings to >> your implementation and any change in implementation requires change in >> the bindings. This contradicts the idea of bindings. >> > > I totally agree. Bindings ID are abstract numbers. > We do follow that. We even document it: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clk/meson/gxbb.h#n118 > > It is just a choice to not expose some IDs. > It is not tied to the implementation at all. > I think we actually follow the rules and the idea behind it. > > We can expose then all If you still think what we are doing is not appropriate. No, no need. You are right and I took your not-by-one-increment-ID by other approaches I saw. The IDs do not have to be incremental, they should not be tied to programming model. You have it done and documented, so thanks for explanation: Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> Best regards, Krzysztof
