# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id:
http://devicetree.org/schemas/soc/qcom/qcom,smsm.yaml#
$schema:
http://devicetree.org/meta-schemas/core.yaml#
title: Qualcomm Shared Memory State Machine
maintainers:
- Andy Gross <agross@kernel.org>
- Bjorn Andersson <bjorn.andersson@linaro.org>
- Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
description:
The Shared Memory State Machine facilitates broadcasting of single bit state
information between the processors in a Qualcomm SoC. Each processor is
assigned 32 bits of state that can be modified. A processor can through a
matrix of bitmaps signal subscription of notifications upon changes to a
certain bit owned by a certain remote processor.
properties:
compatible:
const: qcom,smsm
'#address-cells':
const: 1
qcom,local-host:
$ref: /schemas/types.yaml#/definitions/uint32
default: 0
description:
Identifier of the local processor in the list of hosts, or in other words
specifier of the column in the subscription matrix representing the local
processor.
mboxes:
minItems: 1
maxItems: 5
description:
Reference to the mailbox representing the outgoing doorbell in APCS for
this client. Each entry represents the N:th remote processor by index
(0-indexed).
'#size-cells':
const: 0
patternProperties:
"^qcom,ipc-[1-4]$":
$ref: /schemas/types.yaml#/definitions/phandle-array
items:
- items:
- description: phandle to a syscon node representing the APCS registers
- description: u32 representing offset to the register within the syscon
- description: u32 representing the ipc bit within the register
description:
Three entries specifying the outgoing ipc bit used for signaling the N:th
remote processor.
deprecated: true
"@[0-9a-f]$":
type: object
description:
Each processor's state bits are described by a subnode of the SMSM device
node. Nodes can either be flagged as an interrupt-controller to denote a
remote processor's state bits or the local processors bits. The node
names are not important.
properties:
reg:
maxItems: 1
interrupt-controller:
description:
Marks the entry as a interrupt-controller and the state bits to
belong to a remote processor.
'#interrupt-cells':
const: 2
interrupts:
maxItems: 1
description:
One entry specifying remote IRQ used by the remote processor to
signal changes of its state bits.
'#qcom,smem-state-cells':
$ref: /schemas/types.yaml#/definitions/uint32
const: 1
description:
Required for local entry. Denotes bit number.
required:
- reg
oneOf:
- required:
- '#qcom,smem-state-cells'
- required:
- interrupt-controller
- '#interrupt-cells'
- interrupts
additionalProperties: false
required:
- compatible
- '#address-cells'
- '#size-cells'
oneOf:
- required:
- mboxes
- anyOf:
- required:
- qcom,ipc-1
- required:
- qcom,ipc-2
- required:
- qcom,ipc-3
- required:
- qcom,ipc-4
additionalProperties: false
examples:
# The following example shows the SMEM setup for controlling properties of
# the wireless processor, defined from the 8974 apps processor's
# point-of-view. It encompasses one outbound entry and the outgoing interrupt
# for the wireless processor.
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>
shared-memory {
compatible = "qcom,smsm";
#address-cells = <1>;
#size-cells = <0>;
mboxes = <0>, <0>, <0>, <&apcs 19>;
apps_smsm: apps@0 {
reg = <0>;
#qcom,smem-state-cells = <1>;
};
wcnss_smsm: wcnss@7 {
reg = <7>;
interrupts = <GIC_SPI 144 IRQ_TYPE_EDGE_RISING>;
interrupt-controller;
#interrupt-cells = <2>;
};
};
