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Diffstat (limited to 'Documentation/devicetree/bindings/mailbox/fsl,mu.txt')
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diff --git a/Documentation/devicetree/bindings/mailbox/fsl,mu.txt b/Documentation/devicetree/bindings/mailbox/fsl,mu.txt new file mode 100644 index 000000000..f3cf77eb5 --- /dev/null +++ b/Documentation/devicetree/bindings/mailbox/fsl,mu.txt @@ -0,0 +1,54 @@ +NXP i.MX Messaging Unit (MU) +-------------------------------------------------------------------- + +The Messaging Unit module enables two processors within the SoC to +communicate and coordinate by passing messages (e.g. data, status +and control) through the MU interface. The MU also provides the ability +for one processor to signal the other processor using interrupts. + +Because the MU manages the messaging between processors, the MU uses +different clocks (from each side of the different peripheral buses). +Therefore, the MU must synchronize the accesses from one side to the +other. The MU accomplishes synchronization using two sets of matching +registers (Processor A-facing, Processor B-facing). + +Messaging Unit Device Node: +============================= + +Required properties: +------------------- +- compatible : should be "fsl,<chip>-mu", the supported chips include + imx6sx, imx7s, imx8qxp, imx8qm. + The "fsl,imx6sx-mu" compatible is seen as generic and should + be included together with SoC specific compatible. +- reg : Should contain the registers location and length +- interrupts : Interrupt number. The interrupt specifier format depends + on the interrupt controller parent. +- #mbox-cells: Must be 2. + <&phandle type channel> + phandle : Label name of controller + type : Channel type + channel : Channel number + + This MU support 4 type of unidirectional channels, each type + has 4 channels. A total of 16 channels. Following types are + supported: + 0 - TX channel with 32bit transmit register and IRQ transmit + acknowledgment support. + 1 - RX channel with 32bit receive register and IRQ support + 2 - TX doorbell channel. Without own register and no ACK support. + 3 - RX doorbell channel. + +Optional properties: +------------------- +- clocks : phandle to the input clock. +- fsl,mu-side-b : Should be set for side B MU. + +Examples: +-------- +lsio_mu0: mailbox@5d1b0000 { + compatible = "fsl,imx8qxp-mu"; + reg = <0x0 0x5d1b0000 0x0 0x10000>; + interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>; + #mbox-cells = <2>; +}; |