On 2/26/25 08:51, Krzysztof Kozlowski wrote: > On 25/02/2025 15:57, Fabrice Gasnier wrote: >> On 2/25/25 13:02, Krzysztof Kozlowski wrote: >>> On Mon, Feb 24, 2025 at 07:01:43PM +0100, Fabrice Gasnier wrote: >>>> pwm: >>>> type: object >>>> additionalProperties: false >>>> >>>> properties: >>>> compatible: >>>> - const: st,stm32-pwm-lp >>>> + enum: >>>> + - st,stm32-pwm-lp >>>> + - st,stm32mp25-pwm-lp >>>> >>>> "#pwm-cells": >>>> const: 3 >>>> @@ -69,7 +76,9 @@ properties: >>>> >>>> properties: >>>> compatible: >>>> - const: st,stm32-lptimer-counter >>>> + enum: >>>> + - st,stm32-lptimer-counter >>>> + - st,stm32mp25-lptimer-counter >>> >>> Driver changes suggest many of these are compatible. Why isn't this expressed? >> >> Hi Krzysztof, >> >> The Low Power Timer (LPTIM) hardware isn't fully backward compatible. >> >> At driver level, as indicated in the cover-letter, same feature list as >> on STM32MP1x is supported currently. This is probably what makes it look >> like it's compatible, but it's not fully compatible. > > I don't understand. Same feature list is supported means fully > compatible, but you say not fully compatible. You are aware that > compatible means not the same? > >> >> The hardware controller is a bit different. Some registers/bits has been >> revisited among other things. This is the purpose for these new compatibles. > > We do not discuss new compatibles. We discuss lack of compatibility. If > registers/bits are changed, how existing driver can work with same ID table? Hi Krzysztof, To summarize on dt-bindings side, here is my view, following your comments on per driver basis of the compatible usage. Let's keep these new compatibles: - "st,stm32mp25-lptimer-trigger" - "st,stm32mp25-lptimer-counter" Both reflect not only LPTimer hardware update, but also specific interconnect to other hardware blocks throughout all the STM32MP25 SoC. Other compatible strings may be dropped. Reading the revision/identification register of the LPTimer should be enough for compatibility in the related drivers. I'll update this in next revision of the series. Thanks for reviewing, Best Regards, Fabrice > > > > Best regards, > Krzysztof
