From: Morten Borup Petersen <[email protected]> This patch adds device tree binding for Message Handling Unit controller version 2 from Arm.
Signed-off-by: Morten Borup Petersen <[email protected]> Signed-off-by: Tushar Khandelwal <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] --- .../devicetree/bindings/mailbox/arm,mhuv2.txt | 108 ++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 Documentation/devicetree/bindings/mailbox/arm,mhuv2.txt diff --git a/Documentation/devicetree/bindings/mailbox/arm,mhuv2.txt b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.txt new file mode 100644 index 000000000000..3a05593414bc --- /dev/null +++ b/Documentation/devicetree/bindings/mailbox/arm,mhuv2.txt @@ -0,0 +1,108 @@ +Arm MHUv2 Mailbox Driver +======================== + +The Arm Message-Handling-Unit (MHU) Version 2 is a mailbox controller that has +between 1 and 124 channel windows to provide unidirectional communication with +remote processor(s). + +Given the unidirectional nature of the device, an MHUv2 mailbox may only be +written to or read from. If a pair of MHU devices is implemented between two +processing elements to provide bidirectional communication, these must be +specified as two separate mailboxes. + +A device tree node for an Arm MHUv2 device must specify either a receiver frame +or a sender frame, indicating which end of the unidirectional MHU device which +the device node entry describes. + +An MHU device must be specified with a transport protocol. The transport +protocol of an MHU device determines the method of data transmission as well as +the number of provided mailboxes. +Following are the possible transport protocol types: +- Single-word: An MHU device implements as many mailboxes as it + provides channel windows. Data is transmitted through + the MHU registers. +- Multi-word: An MHU device implements a single mailbox. All channel windows + will be used during transmission. Data is transmitted through + the MHU registers. +- Doorbell: An MHU device implements as many mailboxes as there are flag + bits available in its channel windows. Optionally, data may + be transmitted through a shared memory region, wherein the MHU + is used strictly as an interrupt generation mechanism. + +Mailbox Device Node: +==================== + +Required properties: +-------------------- +- compatible: Shall be "arm,mhuv2" & "arm,primecell" +- reg: Contains the mailbox register address range (base + address and length) +- #mbox-cells Shall be 1 - the index of the channel needed. +- mhu-frame Frame type of the device. + Shall be either "sender" or "receiver" +- mhu-protocol Transport protocol of the device. Shall be one of the + following: "single-word", "multi-word", "doorbell" + +Required properties (receiver frame): +------------------------------------- +- interrupts: Contains the interrupt information corresponding to the + combined interrupt of the receiver frame + +Example: +-------- + + mbox_mw_tx: mhu@10000000 { + compatible = "arm,mhuv2","arm,primecell"; + reg = <0x10000000 0x1000>; + clocks = <&refclk100mhz>; + clock-names = "apb_pclk"; + #mbox-cells = <1>; + mhu-protocol = "multi-word"; + mhu-frame = "sender"; + }; + + mbox_sw_tx: mhu@10000000 { + compatible = "arm,mhuv2","arm,primecell"; + reg = <0x11000000 0x1000>; + clocks = <&refclk100mhz>; + clock-names = "apb_pclk"; + #mbox-cells = <1>; + mhu-protocol = "single-word"; + mhu-frame = "sender"; + }; + + mbox_db_rx: mhu@10000000 { + compatible = "arm,mhuv2","arm,primecell"; + reg = <0x12000000 0x1000>; + clocks = <&refclk100mhz>; + clock-names = "apb_pclk"; + #mbox-cells = <1>; + interrupts = <0 45 4>; + interrupt-names = "mhu_rx"; + mhu-protocol = "doorbell"; + mhu-frame = "receiver"; + }; + + mhu_client: scb@2e000000 { + compatible = "fujitsu,mb86s70-scb-1.0"; + reg = <0 0x2e000000 0x4000>; + mboxes = + // For multi-word frames, client may only instantiate a single + // mailbox for a mailbox controller + <&mbox_mw_tx 0>, + + // For single-word frames, client may instantiate as many + // mailboxes as there are channel windows in the MHU + <&mbox_sw_tx 0>, + <&mbox_sw_tx 1>, + <&mbox_sw_tx 2>, + <&mbox_sw_tx 3>, + + // For doorbell frames, client may instantiate as many mailboxes + // as there are bits available in the combined number of channel + // windows ((channel windows * 32) mailboxes) + <mbox_db_rx 0>, + <mbox_db_rx 1>, + ... + <mbox_db_rx 17>; + }; \ No newline at end of file -- 2.17.1
