On Mon, May 13, 2024 at 08:02:21PM +0200, Patrick DELAUNAY wrote: > Hi, > > On 5/13/24 17:16, Conor Dooley wrote: > > On Mon, May 13, 2024 at 04:34:20PM +0200, Marek Vasut wrote: > > > On 5/13/24 11:56 AM, Patrick Delaunay wrote: > > > > Add new compatible "st,stm32mp13-pwr-reg" for STM32MP13 SoC family. > > > > > > > > Signed-off-by: Patrick Delaunay <patrick.delaunay@xxxxxxxxxxx> > > > > --- > > > > > > > > Changes in v3: > > > > - Replace oneOf/const by enum; solve the V2 issues for dt_binding_check > > > > > > > > Changes in v2: > > > > - update for Rob review, only add compatible for STM32MP13 family > > > > > > > > .../devicetree/bindings/regulator/st,stm32mp1-pwr-reg.yaml | 4 +++- > > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > > > diff --git a/Documentation/devicetree/bindings/regulator/st,stm32mp1-pwr-reg.yaml b/Documentation/devicetree/bindings/regulator/st,stm32mp1-pwr-reg.yaml > > > > index c9586d277f41..c766f0a15a31 100644 > > > > --- a/Documentation/devicetree/bindings/regulator/st,stm32mp1-pwr-reg.yaml > > > > +++ b/Documentation/devicetree/bindings/regulator/st,stm32mp1-pwr-reg.yaml > > > > @@ -11,7 +11,9 @@ maintainers: > > > > properties: > > > > compatible: > > > > - const: st,stm32mp1,pwr-reg > > > > + enum: > > > > + - st,stm32mp1,pwr-reg > > > > + - st,stm32mp13-pwr-reg > > > Should the st,stm32mp1,pwr-reg be treated as fallback compatible for > > > st,stm32mp13-pwr-reg or not ? > > > > > > In other words, should the DT contain: > > > compatible = "st,stm32mp13-pwr-reg", "st,stm32mp1,pwr-reg"; > > > or > > > compatible = "st,stm32mp13-pwr-reg"; > > > ? Which one is preferable ? > > > > > > I think the former one, since the MP13 PWR block could also be operated by > > > older MP1(5) PWR block driver(s) without any adverse effects, except the SD > > > IO domain configuration won't be available, right ? > > Aye, the fallback sounds like what should be being used here, especially > > if another user of the DT might not need to implement the extra domain. > > > Yes it is the the only difference but I think that type of fallback is no > more recommended for different device and > > the PWR device on STM32MP13 and on STM32MP15 are different. > > > The other user of the non-secure device tree don't use the yet the PWR > driver for STM32MP13, > > so for me the fallback is not needed for non secure world (Linux/U-Boot). > > > So I prefer to introduce a new compatible in Linux kernel before the > STM32MP13 PWR node is really used to avoid ABI break in futur. How is it going to break an ABI? If the mp13 implements a functional subset of what the mp1 does, then that's what fallback compatibles are intended for. Marek's mail suggests that this is the case, and therefore a fallback should be used. If code written for the mp1 would not work on the mp13, then a fallback should not be used. Neither I nor Marek are saying that a new compatible should not be created, in case you misunderstood that. This only affects the binding patch, and your driver etc are free to use the mp13 compatible. Thanks, Conor.
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