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# 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@marcan.st>
- Sven Peter <sven@svenpeter.dev>
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:
- enum:
- apple,t8103-asc-mailbox
- apple,t6000-asc-mailbox
- const: apple,asc-mailbox-v4
- 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:
- enum:
- apple,t8103-m3-mailbox
- apple,t6000-m3-mailbox
- const: apple,m3-mailbox-v2
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
power-domains:
maxItems: 1
required:
- compatible
- reg
- interrupts
- interrupt-names
- "#mbox-cells"
additionalProperties: false
examples:
- |
mailbox@77408000 {
compatible = "apple,t8103-asc-mailbox", "apple,asc-mailbox-v4";
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>;
};
|
