Documentation/devicetree/bindings/sound/audio-graph-card.txt

   1 Audio Graph Card:
   2
   3 Audio Graph Card specifies audio DAI connections of SoC <-> codec.
   4 It is based on common bindings for device graphs.
   5 see ${LINUX}/Documentation/devicetree/bindings/graph.txt
   6
   7 Basically, Audio Graph Card property is same as Simple Card.
   8 see ${LINUX}/Documentation/devicetree/bindings/sound/simple-card.txt
   9
  10 Below are same as Simple-Card.
  11
  12 - label
  13 - widgets
  14 - routing
  15 - dai-format
  16 - frame-master
  17 - bitclock-master
  18 - bitclock-inversion
  19 - frame-inversion
  20 - mclk-fs
  21 - dai-tdm-slot-num
  22 - dai-tdm-slot-width
  23 - clocks / system-clock-frequency
  24
  25 Required properties:
  26
  27 - compatible                            : "audio-graph-card";
  28 - dais                                  : list of CPU DAI port{s}
  29
  30 Optional properties:
  31 - pa-gpios: GPIO used to control external amplifier.
  32
  33 Example: Single DAI case
  34
  35         sound_card {
  36                 compatible = "audio-graph-card";
  37
  38                 dais = <&cpu_port>;
  39         };
  40
  41         dai-controller {
  42                 ...
  43                 cpu_port: port {
  44                         cpu_endpoint: endpoint {
  45                                 remote-endpoint = <&codec_endpoint>;
  46
  47                                 dai-format = "left_j";
  48                                 ...
  49                         };
  50                 };
  51         };
  52
  53         audio-codec {
  54                 ...
  55                 port {
  56                         codec_endpoint: endpoint {
  57                                 remote-endpoint = <&cpu_endpoint>;
  58                         };
  59                 };
  60         };
  61
  62 Example: Multi DAI case
  63
  64         sound-card {
  65                 compatible = "audio-graph-card";
  66
  67                 label = "sound-card";
  68
  69                 dais = <&cpu_port0
  70                         &cpu_port1
  71                         &cpu_port2>;
  72         };
  73
  74         audio-codec@0 {
  75                 ...
  76                 port {
  77                         codec0_endpoint: endpoint {
  78                                 remote-endpoint = <&cpu_endpoint0>;
  79                         };
  80                 };
  81         };
  82
  83         audio-codec@1 {
  84                 ...
  85                 port {
  86                         codec1_endpoint: endpoint {
  87                                 remote-endpoint = <&cpu_endpoint1>;
  88                         };
  89                 };
  90         };
  91
  92         audio-codec@2 {
  93                 ...
  94                 port {
  95                         codec2_endpoint: endpoint {
  96                                 remote-endpoint = <&cpu_endpoint2>;
  97                         };
  98                 };
  99         };
 100
 101         dai-controller {
 102                 ...
 103                 ports {
 104                         cpu_port0: port@0 {
 105                                 cpu_endpoint0: endpoint {
 106                                         remote-endpoint = <&codec0_endpoint>;
 107
 108                                         dai-format = "left_j";
 109                                         ...
 110                                 };
 111                         };
 112                         cpu_port1: port@1 {
 113                                 cpu_endpoint1: endpoint {
 114                                         remote-endpoint = <&codec1_endpoint>;
 115
 116                                         dai-format = "i2s";
 117                                         ...
 118                                 };
 119                         };
 120                         cpu_port2: port@2 {
 121                                 cpu_endpoint2: endpoint {
 122                                         remote-endpoint = <&codec2_endpoint>;
 123
 124                                         dai-format = "i2s";
 125                                         ...
 126                                 };
 127                         };
 128                 };
 129         };
 130