On Fri, Jan 25, 2019 at 11:43:16AM -0800, Nicolin Chen wrote: > On Tue, Jan 22, 2019 at 11:14:27AM +0000, Viorel Suman wrote: > > Add the DT binding documentation for NXP Audio Mixer > > CPU DAI driver. > > > > Signed-off-by: Viorel Suman <viorel.suman@xxxxxxx> > > --- > > .../devicetree/bindings/sound/fsl,audmix.txt | 54 ++++++++++++++++++++++ > > 1 file changed, 54 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/sound/fsl,audmix.txt > > > > diff --git a/Documentation/devicetree/bindings/sound/fsl,audmix.txt b/Documentation/devicetree/bindings/sound/fsl,audmix.txt > > new file mode 100644 > > index 0000000..45f807e > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/sound/fsl,audmix.txt > > @@ -0,0 +1,54 @@ > > +NXP Audio Mixer (AUDMIX). > > + > > +The Audio Mixer is a on-chip functional module that allows mixing of two > > +audio streams into a single audio stream. Audio Mixer has two input serial > > +audio interfaces. These are driven by two Synchronous Audio interface > > +modules (SAI). Each input serial interface carries 8 audio channels in its > > +frame in TDM manner. Mixer mixes audio samples of corresponding channels > > +from two interfaces into a single sample. Before mixing, audio samples of > > +two inputs can be attenuated based on configuration. The output of the > > +Audio Mixer is also a serial audio interface. Like input interfaces it has > > +the same TDM frame format. This output is used to drive the serial DAC TDM > > +interface of audio codec and also sent to the external pins along with the > > +receive path of normal audio SAI module for readback by the CPU. > > + > > +The output of Audio Mixer can be selected from any of the three streams > > + - serial audio input 1 > > + - serial audio input 2 > > + - mixed audio > > + > > +Mixing operation is independent of audio sample rate but the two audio > > +input streams must have same audio sample rate with same number of channels > > +in TDM frame to be eligible for mixing. > > + > > +Device driver required properties: > > +================================= > > + - compatible : Compatible list, contains "fsl,imx8qm-audmix" > > + > > + - reg : Offset and length of the register set for the device. > > + > > + - clocks : Must contain an entry for each entry in clock-names. > > + > > + - clock-names : Must include the "ipg" for register access. > > + > > + - power-domains : Must contain the phandle to AUDMIX power domain node > > + > > + - dais : Must contain a list of phandles to AUDMIX connected > > + DAIs. The current implementation requires two phandles > > + to SAI interfaces to be provided, the first SAI in the > > + list being used to route the AUDMIX output. > > + > > + - model : Must contain machine driver name which will configure > > + and instantiate the appropriate audio card. > > I don't feel this is necessary for DT node. The driver should be > able to figure out a proper name for the machine driver: it could > use the compatible string to get "imx8qm-audmix" as the name like > fsl_ssi; Or it could have built-in "imx-audmix" of_device_id data > corresponding to "fsl,imx8qm-audmix" compatible string -- for any > non-imx compatible in the future, use something else. I tend to agree, but either way: Rob Herring <robh@xxxxxxxxxx>
