Add the DT binding documentation for NXP Audio Mixer CPU DAI driver.
Signed-off-by: Viorel Suman viorel.suman@nxp.com Acked-by: Nicolin Chen nicoleotsuka@gmail.com Acked-by: Rob Herring robh@kernel.org --- .../devicetree/bindings/sound/fsl,audmix.txt | 50 ++++++++++++++++++++++ 1 file changed, 50 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..840b7e0 --- /dev/null +++ b/Documentation/devicetree/bindings/sound/fsl,audmix.txt @@ -0,0 +1,50 @@ +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. + +Device driver configuration example: +====================================== + audmix: audmix@59840000 { + compatible = "fsl,imx8qm-audmix"; + reg = <0x0 0x59840000 0x0 0x10000>; + clocks = <&clk IMX8QXP_AUD_AUDMIX_IPG>; + clock-names = "ipg"; + power-domains = <&pd_audmix>; + dais = <&sai4>, <&sai5>; + };