Kernel-4.18.0-80.el8_sti-mailbox

ST Microelectronics Mailbox Driver

Each ST Mailbox IP currently consists of 4 instances of 32 channels. Messages
are passed between Application and Remote processors using shared memory.

Controller

Required properties:

• compatible : Should be “st,stih407-mailbox”
• reg : Offset and length of the device’s register set
• mbox-name : Name of the mailbox
• #mbox-cells: : Must be 2

          <&phandle instance channel direction>
            phandle   : Label name of controller
            instance  : Instance number
            channel   : Channel number
  

Optional properties

• interrupts : Contains the IRQ line for a Rx mailbox

Example:

mailbox0: mailbox@0 {
compatible = “st,stih407-mailbox”;
reg = <0x08f00000 0x1000>;
interrupts = <GIC_SPI 1 IRQ_TYPE_NONE>;
#mbox-cells = <2>;
mbox-name = “a9”;
};

Client

Required properties:

• compatible : Many (See the client docs)
• reg : Shared (between Application and Remote) memory address
• mboxes : Standard property to specify a Mailbox (See ./mailbox.txt)

          Cells must match 'mbox-cells' (See Controller docs above)
  

Optional properties

• mbox-names : Name given to channels seen in the ‘mboxes’ property.

Example:

mailbox_test {
compatible = “mailbox-test”;
reg = <0x[shared_memory_address], [shared_memory_size]>;
mboxes = <&mailbox2 0 1>, <&mailbox0 2 1>;
mbox-names = “tx”, “rx”;
};