# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
# Copyright 2021 ARM Ltd.
%YAML 1.2
---
$id: http://devicetree.org/schemas/firmware/arm,scmi.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: System Control and Management Interface (SCMI) Message Protocol bindings
maintainers:
- Sudeep Holla <sudeep.holla@arm.com>
description: |
The SCMI is intended to allow agents such as OSPM to manage various functions
that are provided by the hardware platform it is running on, including power
and performance functions.
This binding is intended to define the interface the firmware implementing
the SCMI as described in ARM document number ARM DEN 0056 ("ARM System Control
and Management Interface Platform Design Document")[0] provide for OSPM in
the device tree.
[0] https://developer.arm.com/documentation/den0056/latest
properties:
$nodename:
const: scmi
compatible:
oneOf:
- description: SCMI compliant firmware with mailbox transport
items:
- const: arm,scmi
- description: SCMI compliant firmware with ARM SMC/HVC transport
items:
- const: arm,scmi-smc
- description: SCMI compliant firmware with SCMI Virtio transport.
The virtio transport only supports a single device.
items:
- const: arm,scmi-virtio
interrupts:
description:
The interrupt that indicates message completion by the platform
rather than by the return of the smc call. This should not be used
except when the platform requires such behavior.
maxItems: 1
interrupt-names:
const: a2p
mbox-names:
description:
Specifies the mailboxes used to communicate with SCMI compliant
firmware.
items:
- const: tx
- const: rx
mboxes:
description:
List of phandle and mailbox channel specifiers. It should contain
exactly one or two mailboxes, one for transmitting messages("tx")
and another optional for receiving the notifications("rx") if supported.
minItems: 1
maxItems: 2
shmem:
description:
List of phandle pointing to the shared memory(SHM) area, for each
transport channel specified.
minItems: 1
maxItems: 2
'#address-cells':
const: 1
'#size-cells':
const: 0
arm,smc-id:
$ref: /schemas/types.yaml#/definitions/uint32
description:
SMC id required when using smc or hvc transports
protocol@11:
type: object
properties:
reg:
const: 0x11
'#power-domain-cells':
const: 1
required:
- '#power-domain-cells'
protocol@13:
type: object
properties:
reg:
const: 0x13
'#clock-cells':
const: 1
required:
- '#clock-cells'
protocol@14:
type: object
properties:
reg:
const: 0x14
'#clock-cells':
const: 1
required:
- '#clock-cells'
protocol@15:
type: object
properties:
reg:
const: 0x15
'#thermal-sensor-cells':
const: 1
required:
- '#thermal-sensor-cells'
protocol@16:
type: object
properties:
reg:
const: 0x16
'#reset-cells':
const: 1
required:
- '#reset-cells'
protocol@17:
type: object
properties:
reg:
const: 0x17
regulators:
type: object
description:
The list of all regulators provided by this SCMI controller.
patternProperties:
'^regulators@[0-9a-f]+$':
type: object
$ref: "../regulator/regulator.yaml#"
properties:
reg:
maxItems: 1
description: Identifier for the voltage regulator.
required:
- reg
additionalProperties: false
patternProperties:
'^protocol@[0-9a-f]+$':
type: object
description:
Each sub-node represents a protocol supported. If the platform
supports a dedicated communication channel for a particular protocol,
then the corresponding transport properties must be present.
The virtio transport does not support a dedicated communication channel.
properties:
reg:
maxItems: 1
mbox-names:
items:
- const: tx
- const: rx
mboxes:
minItems: 1
maxItems: 2
shmem:
minItems: 1
maxItems: 2
required:
- reg
required:
- compatible
if:
properties:
compatible:
contains:
const: arm,scmi
then:
properties:
interrupts: false
interrupt-names: false
required:
- mboxes
- shmem
else:
if:
properties:
compatible:
contains:
const: arm,scmi-smc
then:
required:
- arm,smc-id
- shmem
examples:
- |
firmware {
scmi {
compatible = "arm,scmi";
mboxes = <&mhuB 0 0>,
<&mhuB 0 1>;
mbox-names = "tx", "rx";
shmem = <&cpu_scp_lpri0>,
<&cpu_scp_lpri1>;
#address-cells = <1>;
#size-cells = <0>;
scmi_devpd: protocol@11 {
reg = <0x11>;
#power-domain-cells = <1>;
};
scmi_dvfs: protocol@13 {
reg = <0x13>;
#clock-cells = <1>;
mboxes = <&mhuB 1 0>,
<&mhuB 1 1>;
mbox-names = "tx", "rx";
shmem = <&cpu_scp_hpri0>,
<&cpu_scp_hpri1>;
};
scmi_clk: protocol@14 {
reg = <0x14>;
#clock-cells = <1>;
};
scmi_sensors: protocol@15 {
reg = <0x15>;
#thermal-sensor-cells = <1>;
};
scmi_reset: protocol@16 {
reg = <0x16>;
#reset-cells = <1>;
};
scmi_voltage: protocol@17 {
reg = <0x17>;
regulators {
#address-cells = <1>;
#size-cells = <0>;
regulator_devX: regulator@0 {
reg = <0x0>;
regulator-max-microvolt = <3300000>;
};
regulator_devY: regulator@9 {
reg = <0x9>;
regulator-min-microvolt = <500000>;
regulator-max-microvolt = <4200000>;
};
};
};
};
};
soc {
#address-cells = <2>;
#size-cells = <2>;
sram@50000000 {
compatible = "mmio-sram";
reg = <0x0 0x50000000 0x0 0x10000>;
#address-cells = <1>;
#size-cells = <1>;
ranges = <0 0x0 0x50000000 0x10000>;
cpu_scp_lpri0: scp-sram-section@0 {
compatible = "arm,scmi-shmem";
reg = <0x0 0x80>;
};
cpu_scp_lpri1: scp-sram-section@80 {
compatible = "arm,scmi-shmem";
reg = <0x80 0x80>;
};
cpu_scp_hpri0: scp-sram-section@100 {
compatible = "arm,scmi-shmem";
reg = <0x100 0x80>;
};
cpu_scp_hpri2: scp-sram-section@180 {
compatible = "arm,scmi-shmem";
reg = <0x180 0x80>;
};
};
};
- |
firmware {
scmi {
compatible = "arm,scmi-smc";
shmem = <&cpu_scp_lpri0 &cpu_scp_lpri1>;
arm,smc-id = <0xc3000001>;
#address-cells = <1>;
#size-cells = <0>;
scmi_devpd1: protocol@11 {
reg = <0x11>;
#power-domain-cells = <1>;
};
};
};
...