On Tue, 2022-06-21 at 09:14 +0200, Krzysztof Kozlowski wrote: > On 20/06/2022 17:50, Nícolas F. R. A. Prado wrote: > > On Mon, Jun 20, 2022 at 10:50:57AM +0200, Krzysztof Kozlowski > > wrote: > > > On 20/06/2022 08:59, Chunfeng Yun wrote: > > > > On Sun, 2022-06-19 at 14:05 +0200, Krzysztof Kozlowski wrote: > > > > > On 19/06/2022 09:46, Chunfeng Yun wrote: > > > > > > On Fri, 2022-06-17 at 18:25 -0700, Krzysztof Kozlowski > > > > > > wrote: > > > > > > > On 17/06/2022 15:29, Nícolas F. R. A. Prado wrote: > > > > > > > > The current clock list in the binding doesn't allow for > > > > > > > > one of > > > > > > > > the > > > > > > > > optional clocks to be missing and a subsequent clock to > > > > > > > > be > > > > > > > > present. > > > > > > > > An > > > > > > > > example where this is an issue is in mt8192.dtsi, which > > > > > > > > has > > > > > > > > "sys_ck", > > > > > > > > "ref_ck", "xhci_ck" and would cause dtbs_check > > > > > > > > warnings. > > > > > > > > > > > > > > > > Change the clock list in a way that allows the middle > > > > > > > > optional > > > > > > > > clocks to > > > > > > > > be missing, while still guaranteeing a fixed order. The > > > > > > > > "ref_ck" is > > > > > > > > kept > > > > > > > > as a const even though it is optional for simplicity, > > > > > > > > since it > > > > > > > > is > > > > > > > > present in all current dts files. > > > > > > > > > > > > > > > > Signed-off-by: Nícolas F. R. A. Prado < > > > > > > > > nfraprado@xxxxxxxxxxxxx> > > > > > > > > --- > > > > > > > > > > > > > > > > .../devicetree/bindings/usb/mediatek,mtk- > > > > > > > > xhci.yaml | 9 > > > > > > > > +++++++-- > > > > > > > > 1 file changed, 7 insertions(+), 2 deletions(-) > > > > > > > > > > > > > > > > diff --git > > > > > > > > a/Documentation/devicetree/bindings/usb/mediatek,mtk- > > > > > > > > xhci.yaml > > > > > > > > b/Documentation/devicetree/bindings/usb/mediatek,mtk- > > > > > > > > xhci.yaml > > > > > > > > index 63cbc2b62d18..99a1b233ec90 100644 > > > > > > > > --- > > > > > > > > a/Documentation/devicetree/bindings/usb/mediatek,mtk- > > > > > > > > xhci.yaml > > > > > > > > +++ > > > > > > > > b/Documentation/devicetree/bindings/usb/mediatek,mtk- > > > > > > > > xhci.yaml > > > > > > > > @@ -80,8 +80,13 @@ properties: > > > > > > > > items: > > > > > > > > - const: sys_ck # required, the following ones > > > > > > > > are > > > > > > > > optional > > > > > > > > - const: ref_ck > > > > > > > > - - const: mcu_ck > > > > > > > > - - const: dma_ck > > > > > > > > + - enum: > > > > > > > > + - mcu_ck > > > > > > > > + - dma_ck > > > > > > > > + - xhci_ck > > > > > > > > + - enum: > > > > > > > > + - dma_ck > > > > > > > > + - xhci_ck > > > > > > > > - const: xhci_ck > > > > > > > > > > > > > > You allow now almost any order here, including incorrect > > > > > > > like > > > > > > > sys,ref,xhci,xhci,xhci. > > > > > > > > > > > > > > The order of clocks has to be fixed and we cannot allow > > > > > > > flexibility. > > > > > > > Are > > > > > > > you sure that these clocks are actually optional (not > > > > > > > wired to > > > > > > > the > > > > > > > device)? > > > > > > > > > > > > In fact, these optional clocks are fixed, due to no gates > > > > > > are > > > > > > provided, > > > > > > SW can't control them by CCF; > > > > > > In this case, I usually use a fixed clock, or ignore it. > > > > > > > > > > But in some versions these clocks are controllable or not? > > > > > > > > Some SoCs are controllable, some ones are not (fixed clock). > > > > > > Thanks for confirming. Then I would prefer to make these clocks > > > required > > > (not optional) and always provide them - via common clock > > > framework or > > > fixed-clock. > > > > Hi Krzysztof and Chunfeng, > > > > thank you both for the feedback. > > > > Since the solution I proposed in this patch is not acceptable I see > > two options: > > 1. Split the clocks in several if blocks matched by compatibles > > 2. Make the clocks required and use fixed-clock nodes for the > > missing clocks in > > the DT > > > > My understanding is that 1 is the desirable solution if the clock > > is really > > missing in some hardware variants, while 2 is desirable if all > > hardware variants > > really receive all the clocks, only that on some variants they're > > fixed and not > > controlable by SW. > > > > From what I'm reading of this discussion it seems that the latter > > is the case > > here and thus we should go for 2. Is this correct? > > This is how I understood it as well, so correct from my side. Also right for me. > > > > > Also Chunfeng, do you have information on whether the same is true > > for the MMC > > HW block? I recently submitted some changes to that binding [1] but > > I followed > > approach 1 there instead. However if all the clocks are present in > > the HW level > > there as well it would make more sense for me to change it to > > follow approach 2. I discussed it with Wenbin, MMC seems a little different with USB, Hi Wenbin, Please give some comments about MMC, thanks > > > > Thanks, > > Nícolas > > > > [1] > > https://lore.kernel.org/all/20220617230114.2438875-1-nfraprado@xxxxxxxxxxxxx > > > Best regards, > Krzysztof
