Apple mailbox controller are found on the M1 and are used for communication with various co-processors. Reviewed-by: Mark Kettenis <kettenis@xxxxxxxxxxx> Reviewed-by: Rob Herring <robh@xxxxxxxxxx> Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx> --- .../bindings/mailbox/apple,mailbox.yaml | 77 +++++++++++++++++++ 1 file changed, 77 insertions(+) create mode 100644 Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml diff --git a/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml b/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml new file mode 100644 index 000000000000..2c1704b34e7a --- /dev/null +++ b/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml @@ -0,0 +1,77 @@ +# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/mailbox/apple,mailbox.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Apple Mailbox Controller + +maintainers: + - Hector Martin <marcan@xxxxxxxxx> + - Sven Peter <sven@xxxxxxxxxxxxx> + +description: + The Apple mailbox consists of two FIFOs used to exchange 64+32 bit + messages between the main CPU and a co-processor. Multiple instances + of this mailbox can be found on Apple SoCs. + One of the two FIFOs is used to send data to a co-processor while the other + FIFO is used for the other direction. + Various clients implement different IPC protocols based on these simple + messages and shared memory buffers. + +properties: + compatible: + oneOf: + - description: + ASC mailboxes are the most common variant found on the M1 used + for example for the display controller, the system management + controller and the NVMe coprocessor. + items: + - const: apple,t8103-asc-mailbox + + - description: + M3 mailboxes are an older variant with a slightly different MMIO + interface still found on the M1. It is used for the Thunderbolt + co-processors. + items: + - const: apple,t8103-m3-mailbox + + reg: + maxItems: 1 + + interrupts: + items: + - description: send fifo is empty interrupt + - description: send fifo is not empty interrupt + - description: receive fifo is empty interrupt + - description: receive fifo is not empty interrupt + + interrupt-names: + items: + - const: send-empty + - const: send-not-empty + - const: recv-empty + - const: recv-not-empty + + "#mbox-cells": + const: 0 + +required: + - compatible + - reg + - interrupts + - interrupt-names + - "#mbox-cells" + +additionalProperties: false + +examples: + - | + mailbox@77408000 { + compatible = "apple,t8103-asc-mailbox"; + reg = <0x77408000 0x4000>; + interrupts = <1 583 4>, <1 584 4>, <1 585 4>, <1 586 4>; + interrupt-names = "send-empty", "send-not-empty", + "recv-empty", "recv-not-empty"; + #mbox-cells = <0>; + }; -- 2.25.1
