On Tue, Oct 19, 2021 at 2:03 AM Stephan Gerhold <stephan@xxxxxxxxxxx> wrote: > > On Mon, Oct 18, 2021 at 03:22:25PM -0500, Rob Herring wrote: > > On Mon, Oct 11, 2021 at 04:17:35PM +0200, Stephan Gerhold wrote: > > > The BAM Data Multiplexer provides access to the network data channels of > > > modems integrated into many older Qualcomm SoCs, e.g. Qualcomm MSM8916 or > > > MSM8974. It is built using a simple protocol layer on top of a DMA engine > > > (Qualcomm BAM) and bidirectional interrupts to coordinate power control. > > > > > > The device tree node combines the incoming interrupt with the outgoing > > > interrupts (smem-states) as well as the two DMA channels, which allows > > > the BAM-DMUX driver to request all necessary resources. > > > > > > Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx> > > > --- > > > Changes since RFC: None. > > > --- > > > .../bindings/net/qcom,bam-dmux.yaml | 87 +++++++++++++++++++ > > > 1 file changed, 87 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml > > > > > > diff --git a/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml b/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml > > > new file mode 100644 > > > index 000000000000..33e125e70cb4 > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/net/qcom,bam-dmux.yaml > > > @@ -0,0 +1,87 @@ > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/net/qcom,bam-dmux.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: Qualcomm BAM Data Multiplexer > > > + > > > +maintainers: > > > + - Stephan Gerhold <stephan@xxxxxxxxxxx> > > > + > > > +description: | > > > + The BAM Data Multiplexer provides access to the network data channels > > > + of modems integrated into many older Qualcomm SoCs, e.g. Qualcomm MSM8916 > > > + or MSM8974. It is built using a simple protocol layer on top of a DMA engine > > > + (Qualcomm BAM DMA) and bidirectional interrupts to coordinate power control. > > > + > > > +properties: > > > + compatible: > > > + const: qcom,bam-dmux > > > > Is this block the same on every SoC? It needs to be SoC specific. > > > > Hm, I think describing it as *SoC*-specific wouldn't be accurate: > This node does not describe any hardware block, it's more a "firmware > convention". The only hardware involved is the BAM DMA engine, which > already has SoC/IP-specific compatibles in its own device tree node. > > This means that if anything there should be "firmware version"-specific > compatibles, because one SoC might have different (typically signed) > firmware versions that provide slightly different functionality. > However, I have to admit that I'm not familiar enough with the different > firmware versions to come up with a reasonable naming schema for the > compatible. :/ > > In general, I cannot think of any difference between different versions > that would matter to a driver. The protocol is quite simple, and minor > firmware differences can be better handled through the control channel > that sets up the connection for the modem. > > Does that make sense? Okay. Please add some of the above details to the binding. Rob
