On 30/06/2022 21:16, Marek Vasut wrote: > On 6/30/22 21:11, Krzysztof Kozlowski wrote: >> On 30/06/2022 19:39, Marek Vasut wrote: >>> Document the LDB bridge subnode and add the subnode into the example. >>> For the subnode to work, the block control must be compatible with >>> simple-mfd in addition to the existing compatibles. >>> >>> Signed-off-by: Marek Vasut <marex@xxxxxxx> >>> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> >>> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> >>> Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx> >>> Cc: NXP Linux Team <linux-imx@xxxxxxx> >>> Cc: Paul Elder <paul.elder@xxxxxxxxxxxxxxxx> >>> Cc: Peng Fan <peng.fan@xxxxxxx> >>> Cc: Rob Herring <robh+dt@xxxxxxxxxx> >>> Cc: devicetree@xxxxxxxxxxxxxxx >>> --- >>> .../soc/imx/fsl,imx8mp-media-blk-ctrl.yaml | 54 ++++++++++++++++++- >>> 1 file changed, 53 insertions(+), 1 deletion(-) >>> >>> diff --git a/Documentation/devicetree/bindings/soc/imx/fsl,imx8mp-media-blk-ctrl.yaml b/Documentation/devicetree/bindings/soc/imx/fsl,imx8mp-media-blk-ctrl.yaml >>> index b246d8386ba4a..05a19d3229830 100644 >>> --- a/Documentation/devicetree/bindings/soc/imx/fsl,imx8mp-media-blk-ctrl.yaml >>> +++ b/Documentation/devicetree/bindings/soc/imx/fsl,imx8mp-media-blk-ctrl.yaml >>> @@ -18,11 +18,18 @@ properties: >>> compatible: >>> items: >>> - const: fsl,imx8mp-media-blk-ctrl >>> + - const: simple-mfd >> >> Not really... simple-mfd means devices is really simple and you just use >> it to instantiate children. However this is not simple - it's a power >> domain controller with several clocks and power domains as input. >> >> It's not a simple MFD, but a regular device. > > I don't understand this comment. The LDB bridge is literally two > registers with a few bits in this media block controller register area. > Can you expand on why the simple-mfd is unsuitable and what should it be > instead ? Looking at the bindings you have there 10 power domains, 10 input clocks and a domain provider. The driver is also not that simple which is another argument that this is not simple-mfd. Simply, it is not simple. What I meant, is that probably you should populate children from the driver instead of adding simple-mfd compatible. Once you add simple-mfd, you cannot remove it and children cannot use anything from the parent. Best regards, Krzysztof
