On 25/09/2023 10:17, Herve Codina wrote: > Hi Krzysztof, > > On Sat, 23 Sep 2023 19:39:49 +0200 > Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx> wrote: > >> On 22/09/2023 09:58, Herve Codina wrote: >>> The QMC (QUICC mutichannel controller) is a controller present in some >>> PowerQUICC SoC such as MPC885. >>> The QMC HDLC uses the QMC controller to transfer HDLC data. >>> >>> Additionally, a framer can be connected to the QMC HDLC. >>> If present, this framer is the interface between the TDM bus used by the >>> QMC HDLC and the E1/T1 line. >>> The QMC HDLC can use this framer to get information about the E1/T1 line >>> and configure the E1/T1 line. >>> >>> Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx> >>> --- >>> .../soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml | 24 +++++++++++++++++++ >>> 1 file changed, 24 insertions(+) >>> >>> diff --git a/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml >>> index 82d9beb48e00..61dfd5ef7407 100644 >>> --- a/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml >>> +++ b/Documentation/devicetree/bindings/soc/fsl/cpm_qe/fsl,cpm1-scc-qmc.yaml >>> @@ -101,6 +101,27 @@ patternProperties: >>> Channel assigned Rx time-slots within the Rx time-slots routed by the >>> TSA to this cell. >>> >>> + compatible: >>> + const: fsl,qmc-hdlc >> >> Why this is not a device/SoC specific compatible? > > This compatible is present in a QMC channel. > The parent node (the QMC itself) contains a compatible with device/SoC: > --- 8< --- > compatible: > items: > - enum: > - fsl,mpc885-scc-qmc > - fsl,mpc866-scc-qmc > - const: fsl,cpm1-scc-qmc > --- 8< --- > > At the child level (ie QMC channel), I am not sure that adding device/SoC > makes sense. This compatible indicates that the QMC channel is handled by > the QMC HDLC driver. > At this level, whatever the device/SoC, we have to be QMC compliant. > > With these details, do you still think I need to change the child (channel) > compatible ? >From OS point of view, you have a driver binding to this child-level compatible. How do you enforce Linux driver binding based on parent compatible? I looked at your next patch and I did not see it. Best regards, Krzysztof
