Add device tree bindings for the Google GS101 Thermal Management Unit
(TMU).
The GS101 TMU is a hybrid thermal solution:
1. Configuration (thresholds, hysteresis) is handled via the Alive
Clock and Power Manager (ACPM) firmware protocol.
2. Interrupt handling is handled by the kernel via direct register
access.
This binding documents the required resources, including the APB clock
for register access and the phandle to the associated syscon node.
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
---
.../bindings/thermal/google,gs101-tmu-top.yaml | 64 ++++++++++++++++++++++
1 file changed, 64 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..ecf4a315ecf1ea0649c4e96a207d531c696282f4
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml
@@ -0,0 +1,64 @@
+# 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@linaro.org>
+
+description: |
+ The Google GS101 TMU is a thermal sensor block managed via the ACPM
+ (Active Core Power Management) firmware. While the firmware handles
+ the thermal algorithm and thresholds, the kernel requires direct
+ access to the interrupt pending registers via a syscon interface to
+ acknowledge and clear thermal interrupts.
+
+properties:
+ compatible:
+ const: google,gs101-tmu-top
+
+ clocks:
+ maxItems: 1
+ description: |
+ Phandle to the APB peripheral clock (PCLK) required to access
+ the TMU registers.
+
+ interrupts:
+ maxItems: 1
+ description: |
+ The combined thermal interrupt signal (Level High).
+
+ syscon:
+ $ref: /schemas/types.yaml#/definitions/phandle
+ description: |
+ Phandle to the device node representing the TMU System Controller
+ (compatible with "google,gs101-tmu-syscon"). This node provides the
+ regmap for INTPEND and INTCLEAR registers.
+
+ "#thermal-sensor-cells":
+ const: 1
+
+required:
+ - compatible
+ - clocks
+ - interrupts
+ - syscon
+ - "#thermal-sensor-cells"
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/clock/google,gs101.h>
+
+ thermal-sensor {
+ compatible = "google,gs101-tmu-top";
+ clocks = <&cmu_misc CLK_GOUT_MISC_TMU_TOP_PCLK>;
+ interrupts = <GIC_SPI 769 IRQ_TYPE_LEVEL_HIGH 0>;
+ syscon = <&tmu_top_syscon>;
+ #thermal-sensor-cells = <1>;
+ };
--
2.52.0.457.g6b5491de43-googOn Wed, Jan 14, 2026 at 02:16:29PM +0000, Tudor Ambarus wrote: > Add device tree bindings for the Google GS101 Thermal Management Unit > (TMU). > > The GS101 TMU is a hybrid thermal solution: > 1. Configuration (thresholds, hysteresis) is handled via the Alive > Clock and Power Manager (ACPM) firmware protocol. > 2. Interrupt handling is handled by the kernel via direct register > access. > > This binding documents the required resources, including the APB clock > for register access and the phandle to the associated syscon node. > > Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> > --- > .../bindings/thermal/google,gs101-tmu-top.yaml | 64 ++++++++++++++++++++++ > 1 file changed, 64 insertions(+) > > diff --git a/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml b/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml > new file mode 100644 > index 0000000000000000000000000000000000000000..ecf4a315ecf1ea0649c4e96a207d531c696282f4 > --- /dev/null > +++ b/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml > @@ -0,0 +1,64 @@ > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > +%YAML 1.2 > +--- > +$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@linaro.org> > + > +description: | > + The Google GS101 TMU is a thermal sensor block managed via the ACPM > + (Active Core Power Management) firmware. While the firmware handles > + the thermal algorithm and thresholds, the kernel requires direct > + access to the interrupt pending registers via a syscon interface to > + acknowledge and clear thermal interrupts. > + > +properties: > + compatible: > + const: google,gs101-tmu-top > + > + clocks: > + maxItems: 1 > + description: | > + Phandle to the APB peripheral clock (PCLK) required to access > + the TMU registers. Drop all the redundancies, so: items: - description: APB peripheral clock (PCLK) for TMU register access > + > + interrupts: > + maxItems: 1 > + description: | > + The combined thermal interrupt signal (Level High). Drop description > + > + syscon: I feel like suddenly you sent something completely different than what have you been working for the past 4 years. > + $ref: /schemas/types.yaml#/definitions/phandle > + description: | > + Phandle to the device node representing the TMU System Controller > + (compatible with "google,gs101-tmu-syscon"). This node provides the > + regmap for INTPEND and INTCLEAR registers. > + > + "#thermal-sensor-cells": > + const: 1 > + No supply? Best regards, Krzysztof
On 1/15/26 3:32 PM, Krzysztof Kozlowski wrote: > On Wed, Jan 14, 2026 at 02:16:29PM +0000, Tudor Ambarus wrote: >> Add device tree bindings for the Google GS101 Thermal Management Unit >> (TMU). >> >> The GS101 TMU is a hybrid thermal solution: >> 1. Configuration (thresholds, hysteresis) is handled via the Alive >> Clock and Power Manager (ACPM) firmware protocol. >> 2. Interrupt handling is handled by the kernel via direct register >> access. >> >> This binding documents the required resources, including the APB clock >> for register access and the phandle to the associated syscon node. >> >> Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org> >> --- >> .../bindings/thermal/google,gs101-tmu-top.yaml | 64 ++++++++++++++++++++++ >> 1 file changed, 64 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml b/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml >> new file mode 100644 >> index 0000000000000000000000000000000000000000..ecf4a315ecf1ea0649c4e96a207d531c696282f4 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml >> @@ -0,0 +1,64 @@ >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) >> +%YAML 1.2 >> +--- >> +$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@linaro.org> >> + >> +description: | >> + The Google GS101 TMU is a thermal sensor block managed via the ACPM >> + (Active Core Power Management) firmware. While the firmware handles >> + the thermal algorithm and thresholds, the kernel requires direct >> + access to the interrupt pending registers via a syscon interface to >> + acknowledge and clear thermal interrupts. >> + >> +properties: >> + compatible: >> + const: google,gs101-tmu-top >> + >> + clocks: >> + maxItems: 1 >> + description: | >> + Phandle to the APB peripheral clock (PCLK) required to access >> + the TMU registers. > > Drop all the redundancies, so: > items: > - description: APB peripheral clock (PCLK) for TMU register access > ack > >> + >> + interrupts: >> + maxItems: 1 >> + description: | >> + The combined thermal interrupt signal (Level High). > > Drop description > ack >> + >> + syscon: > > I feel like suddenly you sent something completely different than what > have you been working for the past 4 years. > >> + $ref: /schemas/types.yaml#/definitions/phandle >> + description: | >> + Phandle to the device node representing the TMU System Controller >> + (compatible with "google,gs101-tmu-syscon"). This node provides the >> + regmap for INTPEND and INTCLEAR registers. >> + >> + "#thermal-sensor-cells": >> + const: 1 >> + > > No supply? It seems not. Nothing specified downstream. Couldn't find anything in the schematics that I have either. I addressed the rest of the feedback in v2. Thanks, ta
On 19/01/2026 13:45, Tudor Ambarus wrote: >>> + "#thermal-sensor-cells": >>> + const: 1 >>> + >> >> No supply? > > It seems not. Nothing specified downstream. Couldn't find anything in the > schematics that I have either. > > I addressed the rest of the feedback in v2. Then maybe it moved to power domain, because TMU always needed power... Best regards, Krzysztof
© 2016 - 2026 Red Hat, Inc.