MLK-13975: ASoC: fsl: add AMIX device driver

Add audio mixer device driver.

Signed-off-by: Viorel Suman <viorel.suman@nxp.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/sound/fsl,amix.txt b/Documentation/devicetree/bindings/sound/fsl,amix.txt
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+NXP Audio Mixer (AMIX).
+
+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-amix"
+
+  - 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 the AMIX power domain node
+
+Device driver configuration example:
+======================================
+  amix: amix@59840000 {
+    compatible = "fsl,imx8qm-amix";
+    reg = <0x0 0x59840000 0x0 0x10000>;
+    clocks = <&clk IMX8QXP_AUD_AMIX_IPG>;
+    clock-names = "ipg";
+    power-domains = <&pd_amix>;
+  };
+
+Machine driver required properties:
+===================================
+  - compatible		: Compatible list, contains "fsl,imx-audio-amix"
+
+  - model		: Short audio card description.
+
+  - dais		: Must contain a list of phandles to AMIX 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 AMIX output.
+
+  - amix-controller	: Must contain the phandle to the AMIX device node.
+
+Machine driver configuration example:
+====================================
+  sound-amix-sai {
+    compatible = "fsl,imx-audio-amix";
+    model = "amix-audio-sai";
+    dais = <&sai4>, <&sai5>;
+    amix-controller = <&amix>;
+  };
+