[PATCH v2 1/7] dt-bindings: thermal: Add Google GS101 TMU

Tudor Ambarus tudor.ambarus at linaro.org
Mon Jan 19 04:08:47 PST 2026


Document the Thermal Management Unit (TMU) found on the Google GS101 SoC.

The GS101 TMU utilizes a hybrid control model shared between the
Application Processor (AP) and the ACPM (Alive Clock and Power Manager)
firmware.

While the TMU is a standard memory-mapped IP block, on this platform
the AP's direct register access is restricted to the interrupt pending
(INTPEND) registers for event identification. High-level functional
tasks, such as sensor initialization, threshold programming, and
temperature reads, are delegated to the ACPM firmware.

Signed-off-by: Tudor Ambarus <tudor.ambarus at linaro.org>
---
 .../bindings/thermal/google,gs101-tmu-top.yaml     | 67 ++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml b/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..b09e1ff5d89194b570810a042c75836ca2e53950
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml
@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/thermal/google,gs101-tmu-top.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google GS101 Thermal Management Unit (TMU)
+
+maintainers:
+  - Tudor Ambarus <tudor.ambarus at linaro.org>
+
+description:
+  The Google GS101 TMU is a thermal sensor block that supports both direct
+  register-level access and firmware-mediated management via the ACPM
+  (Alive Clock and Power Manager) firmware.
+
+  On this platform, the hardware is managed in a hybrid fashion. The
+  Application Processor (AP) maintains direct memory-mapped access
+  exclusively to the interrupt pending registers to identify thermal
+  events. All other functional aspects - including sensor
+  initialization, threshold configuration, and temperature acquisition
+  - are handled by the ACPM firmware. The AP coordinates these
+  operations through the ACPM IPC protocol.
+
+properties:
+  compatible:
+    const: google,gs101-tmu-top
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: APB peripheral clock (PCLK) for TMU register access.
+
+  interrupts:
+    maxItems: 1
+
+  "#thermal-sensor-cells":
+    const: 1
+
+  samsung,acpm-ipc:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: Phandle to the ACPM IPC node.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - interrupts
+  - "#thermal-sensor-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/google,gs101.h>
+
+    thermal-sensor at 100a0000 {
+        compatible = "google,gs101-tmu-top";
+        reg = <0x100a0000 0x800>;
+        clocks = <&cmu_misc CLK_GOUT_MISC_TMU_TOP_PCLK>;
+        interrupts = <GIC_SPI 769 IRQ_TYPE_LEVEL_HIGH 0>;
+        #thermal-sensor-cells = <1>;
+        samsung,acpm-ipc = <&acpm_ipc>;
+    };

-- 
2.52.0.457.g6b5491de43-goog




More information about the linux-arm-kernel mailing list