Documentation/devicetree/bindings/soc/qcom/qcom,glink.txt

   1 Qualcomm GLINK edge binding
   2
   3 This binding describes a Qualcomm GLINK edge, a fifo based mechanism for
   4 communication between subsystem-pairs on various Qualcomm platforms. Two types
   5 of edges can be described by the binding; the GLINK RPM edge and a SMEM based
   6 edge.
   7
   8 - compatible:
   9         Usage: required for glink-rpm
  10         Value type: <stringlist>
  11         Definition: must be "qcom,glink-rpm"
  12
  13 - interrupts:
  14         Usage: required
  15         Value type: <prop-encoded-array>
  16         Definition: should specify the IRQ used by the remote processor to
  17                     signal this processor about communication related events
  18
  19 - qcom,rpm-msg-ram:
  20         Usage: required for glink-rpm
  21         Value type: <prop-encoded-array>
  22         Definition: handle to RPM message memory resource
  23
  24 - mboxes:
  25         Usage: required
  26         Value type: <prop-encoded-array>
  27         Definition: reference to the "rpm_hlos" mailbox in APCS, as described
  28                     in mailbox/mailbox.txt
  29
  30 = GLINK DEVICES
  31 Each subnode of the GLINK node represent function tied to a virtual
  32 communication channel. The name of the nodes are not important. The properties
  33 of these nodes are defined by the individual bindings for the specific function
  34 - but must contain the following property:
  35
  36 - qcom,glink-channels:
  37         Usage: required
  38         Value type: <stringlist>
  39         Definition: a list of channels tied to this function, used for matching
  40                     the function to a set of virtual channels
  41
  42 = EXAMPLE
  43 The following example represents the GLINK RPM node on a MSM8996 device, with
  44 the function for the "rpm_request" channel defined, which is used for
  45 regualtors and root clocks.
  46
  47         apcs_glb: mailbox@9820000 {
  48                 compatible = "qcom,msm8996-apcs-hmss-global";
  49                 reg = <0x9820000 0x1000>;
  50
  51                 #mbox-cells = <1>;
  52         };
  53
  54         rpm_msg_ram: memory@68000 {
  55                 compatible = "qcom,rpm-msg-ram";
  56                 reg = <0x68000 0x6000>;
  57         };
  58
  59         rpm-glink {
  60                 compatible = "qcom,glink-rpm";
  61
  62                 interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
  63
  64                 qcom,rpm-msg-ram = <&rpm_msg_ram>;
  65
  66                 mboxes = <&apcs_glb 0>;
  67
  68                 rpm-requests {
  69                         compatible = "qcom,rpm-msm8996";
  70                         qcom,glink-channels = "rpm_requests";
  71
  72                         ...
  73                 };
  74         };