On Wed, Mar 23, 2022 at 9:11 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote: > > On 23/03/2022 15:00, Adam Ford wrote: > > On Wed, Mar 23, 2022 at 8:56 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote: > >> > >> On 23/03/2022 14:40, Adam Ford wrote: > >>> The SDHC controller in the imx8mn and imx8mp have the same controller > >>> as the imx8mm which is slightly different than that of the imx7d. > >>> Using the fallback of the imx8mm enables the controllers to support > >>> HS400-ES which is not available on the imx7d. > >>> > >>> Signed-off-by: Adam Ford <aford173@xxxxxxxxx> > >>> > >>> diff --git a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml > >>> index 7dbbcae9485c..d6ea73d76bdd 100644 > >>> --- a/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml > >>> +++ b/Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.yaml > >>> @@ -39,14 +39,14 @@ properties: > >>> - items: > >>> - enum: > >>> - fsl,imx8mm-usdhc > >> > >> Your change looks reasonable, but why imx8mm is compatible with imx7d? > > > > I saw that, and I wasn't sure the best way to go about fixing it. If > > I move the 8mm out of the imx7d category, do I need to add it to the > > enum list associated with the imx8mm, or can I just delete it from the > > enum leaving the const for imx8mm good enough? > > > > The DTS is using: > compatible = "fsl,imx8mm-usdhc", "fsl,imx7d-usdhc" > which looks incorrect, based on what you wrote in commit description. > Since fsl,imx8mm-usdhc has its own compatibility-group and defines the > properties for entire family (imx8mm + imx8mn + imx8mp), then I would > assume that either fsl,imx8mm-usdhc is not be compatible with imx7d or > everything is compatible with imx7d. IOW, DTS and bindings should be > changed to one of following: > 1. Everything compatible with imx7d: > compatible = "fsl,imx8mm-usdhc", "fsl,imx7d-usdhc"; > compatible = "fsl,imx8mq-usdhc", "fsl,imx8mm-usdhc", "fsl,imx7d-usdhc"; > > 2. A new group: > compatible = "fsl,imx8mm-usdhc"; > compatible = "fsl,imx8mq-usdhc", "fsl,imx8mm-usdhc"; > > Which one, I am not sure. My commit 80fd350b95 organized it in (1) > approach, because also that time there was no new group for 8mm (added > in commit 431fae8). I assume NXP engineer knows better, so the better > solution would be (2). In such case, imx8mm has to be moved to the first > enum and all DTS have to be adjusted. I pulled NXP's downtream kernel based on 5.15.y, and grepped the code for imx8mm-usdhc. It looks like the imx8mm, imx8mn, imx8mp, and imx8ulp use the imx8mm compatible flag. The imx8mq uses the older imx7d. I'll do a second revision later today or tomorrow. Looking inside the driver, it appears there are some other quirks that different between the imx7d and imx8mm beyond just support for HS400-ES, so I think your option 2 is appropriate. Hopefully someone from NXP can comment. adam > > > Best regards, > Krzysztof
