Kernel-4.18.0-80.el8_hisilicon,hi6220-mailbox

Hisilicon Hi6220 Mailbox Driver

Hisilicon Hi6220 mailbox supports up to 32 channels. Each channel
is unidirectional with a maximum message size of 8 words. I/O is
performed using register access (there is no DMA) and the cell
raises an interrupt when messages are received.

Mailbox Device Node:

Required properties:

• compatible: Shall be “hisilicon,hi6220-mbox”
• reg: Contains the mailbox register address range (base

        address and length); the first item is for IPC
        registers, the second item is shared buffer for
        slots.
  

• #mbox-cells: Common mailbox binding property to identify the number

        of cells required for the mailbox specifier. Must be 3.
        <&phandle slot_id dst_irq ack_irq>
          phandle: Label name of mailbox controller
          slot_id: Slot id used either for TX or RX
          dst_irq: IRQ identifier index number which used by MCU
          ack_irq: IRQ identifier index number with generating a
                   TX/RX interrupt to application processor,
               mailbox driver uses it to acknowledge interrupt
  

• interrupts: Contains the interrupt information for the mailbox

        device. The format is dependent on which interrupt
        controller the SoCs use.
  

Optional Properties:

• hi6220,mbox-tx-noirq: Property of MCU firmware’s feature, so mailbox driver

        use this flag to ask MCU to enable "automatic idle
        flag" mode or IRQ generated mode to acknowledge a TX
        completion.
  

Example:

mailbox: mailbox@f7510000 {
    compatible = "hisilicon,hi6220-mbox";
    reg = <0x0 0xf7510000 0x0 0x1000>, /* IPC_S */
          <0x0 0x06dff800 0x0 0x0800>; /* Mailbox */
    interrupt-parent = <&gic>;
    interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>;
    #mbox-cells = <3>;
};

Mailbox client

Required properties:

• compatible: Many (See the client docs).
• mboxes: Standard property to specify a Mailbox (See ./mailbox.txt)

        Cells must match 'mbox-cells' (See Mailbox Device Node above).
  

Optional Properties:

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

Example:

stub_clock: stub_clock {
    compatible = "hisilicon,hi6220-stub-clk";
    hisilicon,hi6220-clk-sram = <&sram>;
    #clock-cells = <1>;
    mbox-names = "mbox-tx", "mbox-rx";
    mboxes = <&mailbox 1 0 11>, <&mailbox 0 1 10>;
};