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Diffstat (limited to 'Documentation/devicetree/bindings/mailbox/arm-mhu.txt')
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diff --git a/Documentation/devicetree/bindings/mailbox/arm-mhu.txt b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt new file mode 100644 index 000000000..4971f03f0 --- /dev/null +++ b/Documentation/devicetree/bindings/mailbox/arm-mhu.txt @@ -0,0 +1,43 @@ +ARM MHU Mailbox Driver +====================== + +The ARM's Message-Handling-Unit (MHU) is a mailbox controller that has +3 independent channels/links to communicate with remote processor(s). + MHU links are hardwired on a platform. A link raises interrupt for any +received data. However, there is no specified way of knowing if the sent +data has been read by the remote. This driver assumes the sender polls +STAT register and the remote clears it after having read the data. +The last channel is specified to be a 'Secure' resource, hence can't be +used by Linux running NS. + +Mailbox Device Node: +==================== + +Required properties: +-------------------- +- compatible: Shall be "arm,mhu" & "arm,primecell" +- reg: Contains the mailbox register address range (base + address and length) +- #mbox-cells Shall be 1 - the index of the channel needed. +- interrupts: Contains the interrupt information corresponding to + each of the 3 links of MHU. + +Example: +-------- + + mhu: mailbox@2b1f0000 { + #mbox-cells = <1>; + compatible = "arm,mhu", "arm,primecell"; + reg = <0 0x2b1f0000 0x1000>; + interrupts = <0 36 4>, /* LP-NonSecure */ + <0 35 4>, /* HP-NonSecure */ + <0 37 4>; /* Secure */ + clocks = <&clock 0 2 1>; + clock-names = "apb_pclk"; + }; + + mhu_client: scb@2e000000 { + compatible = "fujitsu,mb86s70-scb-1.0"; + reg = <0 0x2e000000 0x4000>; + mboxes = <&mhu 1>; /* HP-NonSecure */ + }; |