| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20250819-macsmc-subdevs-v1-2-57df6c3e5f19@gmail.com>
Date: Tue, 19 Aug 2025 21:47:54 +1000
From: James Calligeros <jcalligeros99@...il.com>
To: Sven Peter <sven@...nel.org>, Janne Grunau <j@...nau.net>,
Alyssa Rosenzweig <alyssa@...enzweig.io>, Neal Gompa <neal@...pa.dev>,
Lee Jones <lee@...nel.org>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>,
Alexandre Belloni <alexandre.belloni@...tlin.com>,
Jean Delvare <jdelvare@...e.com>, Guenter Roeck <linux@...ck-us.net>,
Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc: asahi@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-rtc@...r.kernel.org, linux-hwmon@...r.kernel.org,
linux-input@...r.kernel.org, James Calligeros <jcalligeros99@...il.com>
Subject: [PATCH 2/8] dt-bindings: hwmon: add Apple System Management
Controller hwmon schema
Apple Silicon devices integrate a vast array of sensors, monitoring
current, power, temperature, and voltage across almost every part of
the system. The sensors themselves are all connected to the System
Management Controller (SMC). The SMC firmware exposes the data
reported by these sensors via its standard FourCC-based key-value
API. The SMC is also responsible for monitoring and controlling any
fans connected to the system, exposing them in the same way.
For reasons known only to Apple, each device exposes its sensors with
an almost totally unique set of keys. This is true even for devices
which share an SoC. An M1 Mac mini, for example, will report its core
temperatures on different keys to an M1 MacBook Pro. Worse still, the
SMC does not provide a way to enumerate the available keys at runtime,
nor do the keys follow any sort of reasonable or consistent naming
rules that could be used to deduce their purpose. We must therefore
know which keys are present on any given device, and which function
they serve, ahead of time.
Add a schema so that we can describe the available sensors for a given
Apple Silicon device in the Devicetree.
Signed-off-by: James Calligeros <jcalligeros99@...il.com>
---
.../bindings/hwmon/apple,smc-hwmon.yaml | 148 +++++++++++++++++++++++++
.../bindings/mfd/apple,smc.yaml | 45 ++++++++
2 files changed, 193 insertions(+)
diff --git a/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml b/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..3ebc0463be4e1ce54005418feaa87ec7254dab6e
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/apple,smc-hwmon.yaml
@@ -0,0 +1,148 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/apple,smc-hwmon.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SMC Hardware Monitoring
+
+description:
+ Apple's System Management Controller (SMC) exposes a vast array of
+ hardware monitoring sensors, including temperature probes, current and
+ voltage sense, power meters, and fan speeds. It also provides endpoints
+ to manually control the speed of each fan individually. Each Apple
+ Silicon device exposes a different set of endpoints via SMC keys. This
+ is true even when two machines share an SoC. The CPU core temperature
+ sensor keys on an M1 Mac mini are different to those on an M1 MacBook
+ Pro, for example.
+
+maintainers:
+ - James Calligeros <jcalligeros99@...il.com>
+
+properties:
+ compatible:
+ const: apple,smc-hwmon
+
+ current:
+ description: SMC current sense endpoints
+ type: object
+ additionalProperties: false
+ patternProperties:
+ "^current-[A-Za-z0-9]{4}":
+ type: object
+ additionalProperties: false
+ required:
+ - apple,key-id
+ properties:
+ apple,key-id:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: The SMC FourCC key of the desired current sensor.
+ Should match the node's suffix, but doesn't have to.
+ label:
+ $ref: /schemas/types.yaml#/definitions/string
+ description: Human-readable name for the sensor
+
+ fan:
+ description: SMC fan control endpoints. A fan is made up of five
+ SMC keys - the fan's current speed, its minimum speed, its maximum
+ speed, a writeable target speed, and a writeable mode. The SMC will
+ automatically manage system fans unless a 1 is written to the fan's
+ mode key.
+ type: object
+ additionalProperties: false
+ patternProperties:
+ "^fan-[A-Za-z0-9]{4}":
+ type: object
+ additionalProperties: false
+ required:
+ - apple,key-id
+ properties:
+ apple,key-id:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: The SMC FourCC key of the desired fan. This is the
+ main key, which reports the fan's current speed. Sould match
+ the node's suffix, but doesn't have to.
+ apple,fan-minimum:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: The minimum speed the current fan can run at
+ apple,fan-maximum:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: The maximum speed the current fan can run at
+ apple,fan-target:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: Writeable endpoint for setting desired fan speed
+ apple,fan-mode:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: Writeable endpoint to enable/disable manual fan
+ control
+ label:
+ $ref: /schemas/types.yaml#/definitions/string
+ description: Human-readable name for the sensor
+
+ power:
+ description: SMC power meter endpoints
+ type: object
+ additionalProperties: false
+ patternProperties:
+ "^power-[A-Za-z0-9]{4}":
+ type: object
+ additionalProperties: false
+ required:
+ - apple,key-id
+ properties:
+ apple,key-id:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: The SMC FourCC key of the desired power meter.
+ Should match the node's suffix, but doesn't have to.
+ label:
+ $ref: /schemas/types.yaml#/definitions/string
+ description: Human-readable name for the sensor
+
+ temperature:
+ description: SMC temperature sensor endpoints
+ type: object
+ additionalProperties: false
+ patternProperties:
+ "^temperature-[A-Za-z0-9]{4}":
+ type: object
+ additionalProperties: false
+ required:
+ - apple,key-id
+ properties:
+ apple,key-id:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: The SMC FourCC key of the desired temperature
+ sensor. Should match the node's suffix, but doesn't have to.
+ label:
+ $ref: /schemas/types.yaml#/definitions/string
+ description: Human-readable name for the sensor
+
+ voltage:
+ description: SMC voltage sensor endpoints
+ type: object
+ additionalProperties: false
+ patternProperties:
+ "^voltage-[A-Za-z0-9]{4}":
+ type: object
+ additionalProperties: false
+ required:
+ - apple,key-id
+ properties:
+ apple,key-id:
+ $ref: /schemas/types.yaml#/definitions/string
+ pattern: "^[A-Za-z0-9]{4}"
+ description: The SMC FourCC key of the desired voltage
+ sensor. Should match the node's suffix, but doesn't have to.
+ label:
+ $ref: /schemas/types.yaml#/definitions/string
+ description: Human-readable name for the sensor
+
+additionalProperties: false
diff --git a/Documentation/devicetree/bindings/mfd/apple,smc.yaml b/Documentation/devicetree/bindings/mfd/apple,smc.yaml
index 38f077867bdeedba8a486a63e366e9c943a75681..370928bb42010edca17839faf0bda4630611a7a2 100644
--- a/Documentation/devicetree/bindings/mfd/apple,smc.yaml
+++ b/Documentation/devicetree/bindings/mfd/apple,smc.yaml
@@ -44,6 +44,9 @@ properties:
rtc:
$ref: /schemas/rtc/apple,smc-rtc.yaml
+ hwmon:
+ $ref: /schemas/hwmon/apple,smc-hwmon.yaml
+
additionalProperties: false
required:
@@ -84,5 +87,47 @@ examples:
nvmem-cells = <&rtc_offset>;
nvmem-cell-names = "rtc_offset";
};
+
+ hwmon {
+ compatible = "apple,smc-hwmon";
+ current {
+ current-ID0R {
+ apple,key-id = "ID0R";
+ label = "AC Input Current";
+ };
+ };
+
+ fan {
+ fan-F0Ac {
+ apple,key-id = "F0Ac";
+ apple,fan-minimum = "F0Mn";
+ apple,fan-maximum = "F0Mx";
+ apple,fan-target = "F0Tg";
+ apple,fan-mode = "F0Md";
+ label = "Fan 1";
+ };
+ };
+
+ power {
+ power-PSTR {
+ apple,key-id = "PSTR";
+ label = "Total System Power";
+ };
+ };
+
+ temperature {
+ temperature-TW0P {
+ apple,key-id = "TW0P";
+ label = "WiFi/BT Module Temperature";
+ };
+ };
+
+ voltage {
+ voltage-VD0R {
+ apple,key-id = "VD0R";
+ label = "AC Input Voltage";
+ };
+ };
+ };
};
};
--
2.50.1
Powered by blists - more mailing lists