On Wed, 3 Jun 2026 at 14:00, Tudor Ambarus <[email protected]> wrote: > > 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. This hybrid ACPM TMU architecture is also present on other > Samsung Exynos SoCs (e.g., AutoV920, Exynos850). > > 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 <[email protected]> > Reviewed-by: Krzysztof Kozlowski <[email protected]> > ---
Reviewed-by: Peter Griffin <[email protected]> > .../bindings/thermal/google,gs101-tmu-top.yaml | 69 > ++++++++++++++++++++++ > 1 file changed, 69 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 000000000000..75560ebca48d > --- /dev/null > +++ b/Documentation/devicetree/bindings/thermal/google,gs101-tmu-top.yaml > @@ -0,0 +1,69 @@ > +# 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: Samsung Exynos ACPM Thermal Management Unit (TMU) > + > +maintainers: > + - Tudor Ambarus <[email protected]> > + > +description: > + The Samsung Exynos ACPM TMU is a thermal sensor block found on Exynos > + based platforms (such as Google GS101 and Exynos850). It supports > + both direct register-level access and firmware-mediated management > + via the ACPM (Alive Clock and Power Manager) firmware. > + > + On these platforms, 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" > + - samsung,acpm-ipc > + > +additionalProperties: false > + > +examples: > + - | > + #include <dt-bindings/interrupt-controller/arm-gic.h> > + #include <dt-bindings/clock/google,gs101.h> > + > + thermal-sensor@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>; > + }; > > -- > 2.54.0.1013.g208068f2d8-goog >
