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 - dai-tdm-slot-num
  21 - dai-tdm-slot-width
  22 - clocks / system-clock-frequency
  23
  24 Required properties:
  25
  26 - compatible                            : "audio-graph-card";
  27 - dais                                  : list of CPU DAI port{s}
  28
  29 Optional properties:
  30 - pa-gpios: GPIO used to control external amplifier.
  31
  32 Example: Single DAI case
  33
  34         sound_card {
  35                 compatible = "audio-graph-card";
  36
  37                 dais = <&cpu_port>;
  38         };
  39
  40         dai-controller {
  41                 ...
  42                 cpu_port: port {
  43                         cpu_endpoint: endpoint {
  44                                 remote-endpoint = <&codec_endpoint>;
  45
  46                                 dai-format = "left_j";
  47                                 ...
  48                         };
  49                 };
  50         };
  51
  52         audio-codec {
  53                 ...
  54                 port {
  55                         codec_endpoint: endpoint {
  56                                 remote-endpoint = <&cpu_endpoint>;
  57                         };
  58                 };
  59         };
  60
  61 Example: Multi DAI case
  62
  63         sound-card {
  64                 compatible = "audio-graph-card";
  65
  66                 label = "sound-card";
  67
  68                 dais = <&cpu_port0
  69                         &cpu_port1
  70                         &cpu_port2>;
  71         };
  72
  73         audio-codec@0 {
  74                 ...
  75                 port {
  76                         codec0_endpoint: endpoint {
  77                                 remote-endpoint = <&cpu_endpoint0>;
  78                         };
  79                 };
  80         };
  81
  82         audio-codec@1 {
  83                 ...
  84                 port {
  85                         codec1_endpoint: endpoint {
  86                                 remote-endpoint = <&cpu_endpoint1>;
  87                         };
  88                 };
  89         };
  90
  91         audio-codec@2 {
  92                 ...
  93                 port {
  94                         codec2_endpoint: endpoint {
  95                                 remote-endpoint = <&cpu_endpoint2>;
  96                         };
  97                 };
  98         };
  99
 100         dai-controller {
 101                 ...
 102                 ports {
 103                         cpu_port0: port@0 {
 104                                 cpu_endpoint0: endpoint {
 105                                         remote-endpoint = <&codec0_endpoint>;
 106
 107                                         dai-format = "left_j";
 108                                         ...
 109                                 };
 110                         };
 111                         cpu_port1: port@1 {
 112                                 cpu_endpoint1: endpoint {
 113                                         remote-endpoint = <&codec1_endpoint>;
 114
 115                                         dai-format = "i2s";
 116                                         ...
 117                                 };
 118                         };
 119                         cpu_port2: port@2 {
 120                                 cpu_endpoint2: endpoint {
 121                                         remote-endpoint = <&codec2_endpoint>;
 122
 123                                         dai-format = "i2s";
 124                                         ...
 125                                 };
 126                         };
 127                 };
 128         };
 129