Documentation/devicetree/bindings/mailbox/arm-mhu.txt

   1 ARM MHU Mailbox Driver
   2 ======================
   3
   4 The ARM's Message-Handling-Unit (MHU) is a mailbox controller that has
   5 3 independent channels/links to communicate with remote processor(s).
   6  MHU links are hardwired on a platform. A link raises interrupt for any
   7 received data. However, there is no specified way of knowing if the sent
   8 data has been read by the remote. This driver assumes the sender polls
   9 STAT register and the remote clears it after having read the data.
  10 The last channel is specified to be a 'Secure' resource, hence can't be
  11 used by Linux running NS.
  12
  13 Mailbox Device Node:
  14 ====================
  15
  16 Required properties:
  17 --------------------
  18 - compatible:           Shall be "arm,mhu" & "arm,primecell"
  19 - reg:                  Contains the mailbox register address range (base
  20                         address and length)
  21 - #mbox-cells           Shall be 1 - the index of the channel needed.
  22 - interrupts:           Contains the interrupt information corresponding to
  23                         each of the 3 links of MHU.
  24
  25 Example:
  26 --------
  27
  28         mhu: mailbox@2b1f0000 {
  29                 #mbox-cells = <1>;
  30                 compatible = "arm,mhu", "arm,primecell";
  31                 reg = <0 0x2b1f0000 0x1000>;
  32                 interrupts = <0 36 4>, /* LP-NonSecure */
  33                              <0 35 4>, /* HP-NonSecure */
  34                              <0 37 4>; /* Secure */
  35                 clocks = <&clock 0 2 1>;
  36                 clock-names = "apb_pclk";
  37         };
  38
  39         mhu_client: scb@2e000000 {
  40                 compatible = "fujitsu,mb86s70-scb-1.0";
  41                 reg = <0 0x2e000000 0x4000>;
  42                 mboxes = <&mhu 1>; /* HP-NonSecure */
  43         };