[PATCH v7 0/4] arm64: amlogic: T7 thermal support

[PATCH v7 0/4] arm64: amlogic: T7 thermal support

[Ronald Claveau via B4 Relay]

This series adds thermal monitoring support for the Amlogic T7 SoC,
used on the Khadas VIM4 board.

The T7 exposes six thermal sensors (a53, a73, gpu, nna, vpu, hevc),
each accessible through the secure monitor firmware interface rather
than a directly mapped eFuse register as on older SoCs.

The series is organized as follows:

- Patch 1 extends the amlogic,t7-thermal DT binding to describe the
  new amlogic,secure-monitor property.
- Patches 2-3 extend the Meson secure monitor driver to expose a
  thermal calibration read command (SMC ID 0x82000047).
- Patch 4 adds the secure monitor readout path to the amlogic thermal
  driver and introduces the amlogic,t7-thermal compatible.
- Patches 5-7 wire up the T7 DTSI with CPU cooling cells, sensor
  nodes, and thermal zones.
- Patch 8 extends the Khadas VIM4 DTS to map all thermal zones to the
  on-board MCU fan controller (states 30–100, corresponding to the
  FAN_CTRL register range 0x1E–0x64).

Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
Changes in v7:
- PATCH 3: Fix four hot thermal zone trip points declared as passive type instead of hot type.
- Link to v6: https://lore.kernel.org/r/20261015-add-thermal-t7-vim4-v6-0-37d1c954390c@aliel.fr

Changes in v6:
- Rebased on next-20261014 (patches 1/8 to 4/8 already applied, dropped from this series).
- PATCH 2: Add bus clocks and clock-names to all thermal sensor nodes.
- PATCH 4: Change cooling device map min and max values from 30-100 to 1-5.
           The driver maps (0,1,2,3,4,5) to (0,30,40,55,75,100)
- Link to v5: https://lore.kernel.org/r/20260424-add-thermal-t7-vim4-v5-0-9040ca36afe2@aliel.fr

Changes in v5:
- PATCH 4: Remove unnecessary variable and coding style alignment
           according to Neil's feedback.
- Link to v4: https://lore.kernel.org/r/20260423-add-thermal-t7-vim4-v4-0-d4c1528d5044@aliel.fr

Changes in v4:
- PATCH 4: Extract SM and syscon setup into amlogic_thermal_probe_sm() and
           amlogic_thermal_probe_syscon() removing amlogic_thermal_initialize()
           from Daniel's feedback.
           Also fix pre-existing bug: move calibration readout before
           devm_thermal_of_zone_register() to avoid reading uninitialized
           trim_info, according to Daniel's feedback.
- Link to v3: https://lore.kernel.org/r/20260421-add-thermal-t7-vim4-v3-0-a2e7215ed003@aliel.fr

Changes in v3:
- PATCH 1: Replace second if check by an else statement.
  Remove unnecessary label in example according to Conor's feedback
- Link to v2: https://lore.kernel.org/r/20260413-add-thermal-t7-vim4-v2-0-1002d90a0602@aliel.fr

Changes in v2:
- PATCH 1: change two const entries to enum, explain why sensor index is needed
  reorder conditional compatible for required, and fallback only according to
  Krzysztof's feedback.
- PATCH 3: Add kerneldoc for meson_sm_get_thermal_calib exported function
  according to Krzysztof's feedback.
- Link to v1: https://lore.kernel.org/r/20260410-add-thermal-t7-vim4-v1-0-19f2b8da74d7@aliel.fr

---
Ronald Claveau (4):
      arm64: dts: amlogic: t7: Add cooling cells to all CPUs
      arm64: dts: amlogic: t7: Add thermal sensor nodes
      arm64: dts: amlogic: t7: Add thermal zones
      arm64: dts: amlogic: t7: khadas-vim4: Add fan cooling to thermal zones

 .../dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts  | 102 +++++++++
 arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi        | 253 +++++++++++++++++++++
 2 files changed, 355 insertions(+)
---
base-commit: ab8eada9868faeee95f25d81d3d6fed0d1c98b78
change-id: 20260410-add-thermal-t7-vim4-00e571badcc1

Best regards,
-- 
Ronald Claveau <linux-kernel-dev@aliel.fr>



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[PATCH v7 1/4] arm64: dts: amlogic: t7: Add cooling cells to all CPUs

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Add #cooling-cells = <2> to all CPU nodes (both little and big cluster)
to allow them to be used as cooling devices in thermal zone mappings.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
index 6894c06a836bc..8aa85aab30469 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
@@ -63,6 +63,7 @@ cpu100: cpu@100 {
 			i-cache-size = <0x8000>;
 			i-cache-sets = <32>;
 			next-level-cache = <&l2_cache_l>;
+			#cooling-cells = <2>;
 		};
 
 		cpu101: cpu@101 {
@@ -77,6 +78,7 @@ cpu101: cpu@101 {
 			i-cache-size = <0x8000>;
 			i-cache-sets = <32>;
 			next-level-cache = <&l2_cache_l>;
+			#cooling-cells = <2>;
 		};
 
 		cpu102: cpu@102 {
@@ -91,6 +93,7 @@ cpu102: cpu@102 {
 			i-cache-size = <0x8000>;
 			i-cache-sets = <32>;
 			next-level-cache = <&l2_cache_l>;
+			#cooling-cells = <2>;
 		};
 
 		cpu103: cpu@103 {
@@ -105,6 +108,7 @@ cpu103: cpu@103 {
 			i-cache-size = <0x8000>;
 			i-cache-sets = <32>;
 			next-level-cache = <&l2_cache_l>;
+			#cooling-cells = <2>;
 		};
 
 		cpu0: cpu@0 {
@@ -119,6 +123,7 @@ cpu0: cpu@0 {
 			i-cache-size = <0x10000>;
 			i-cache-sets = <64>;
 			next-level-cache = <&l2_cache_b>;
+			#cooling-cells = <2>;
 		};
 
 		cpu1: cpu@1 {
@@ -133,6 +138,7 @@ cpu1: cpu@1 {
 			i-cache-size = <0x10000>;
 			i-cache-sets = <64>;
 			next-level-cache = <&l2_cache_b>;
+			#cooling-cells = <2>;
 		};
 
 		cpu2: cpu@2 {
@@ -147,6 +153,7 @@ cpu2: cpu@2 {
 			i-cache-size = <0x10000>;
 			i-cache-sets = <64>;
 			next-level-cache = <&l2_cache_b>;
+			#cooling-cells = <2>;
 		};
 
 		cpu3: cpu@3 {
@@ -161,6 +168,7 @@ cpu3: cpu@3 {
 			i-cache-size = <0x10000>;
 			i-cache-sets = <64>;
 			next-level-cache = <&l2_cache_b>;
+			#cooling-cells = <2>;
 		};
 
 		l2_cache_l: l2-cache-cluster0 {

-- 
2.49.0



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[PATCH v7 2/4] arm64: dts: amlogic: t7: Add thermal sensor nodes

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Add six temperature sensor nodes using the amlogic,t7-thermal compatible:
a73, a53, gpu, nna, vpu, and hevc. Each sensor retrieves its calibration
data from the secure monitor via the amlogic,secure-monitor phandle with
the corresponding tsensor_id argument.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi | 66 +++++++++++++++++++++++++++++
 1 file changed, 66 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
index 8aa85aab30469..c81632d3984e8 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
@@ -696,6 +696,26 @@ sec_ao: ao-secure@10220 {
 				amlogic,has-chip-id;
 			};
 
+			a73_tsensor: temperature-sensor@20000 {
+				compatible = "amlogic,t7-thermal";
+				reg = <0x0 0x20000 0x0 0x50>;
+				interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&clkc_periphs CLKID_SYS_TS_A73>, <&clkc_periphs CLKID_TS>;
+				clock-names = "bus", "core";
+				#thermal-sensor-cells = <0>;
+				amlogic,secure-monitor = <&sm 1>;
+			};
+
+			a53_tsensor: temperature-sensor@22000 {
+				compatible = "amlogic,t7-thermal";
+				reg = <0x0 0x22000 0x0 0x50>;
+				interrupts = <GIC_SPI 30 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&clkc_periphs CLKID_SYS_TS_A53>, <&clkc_periphs CLKID_TS>;
+				clock-names = "bus", "core";
+				#thermal-sensor-cells = <0>;
+				amlogic,secure-monitor = <&sm 2>;
+			};
+
 			pwm_ao_ef: pwm@30000 {
 				compatible = "amlogic,t7-pwm", "amlogic,meson-s4-pwm";
 				reg = <0x0 0x30000 0x0 0x24>;
@@ -818,6 +838,52 @@ sd_emmc_c: mmc@8c000 {
 				assigned-clock-parents = <&xtal>;
 				status = "disabled";
 			};
+
+			gpu_tsensor: temperature-sensor@94000 {
+				compatible = "amlogic,t7-thermal";
+				reg = <0x0 0x94000 0x0 0x50>;
+				interrupts = <GIC_SPI 83 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&clkc_periphs CLKID_SYS_TS_GPU>, <&clkc_periphs CLKID_TS>;
+				clock-names = "bus", "core";
+				power-domains = <&pwrc PWRC_T7_MALI_TOP_ID>;
+				#thermal-sensor-cells = <0>;
+				amlogic,secure-monitor = <&sm 3>;
+			};
+
+			nna_tsensor: temperature-sensor@96000 {
+				compatible = "amlogic,t7-thermal";
+				reg = <0x0 0x96000 0x0 0x50>;
+				interrupts = <GIC_SPI 84 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&clkc_periphs CLKID_SYS_TS_NNA>, <&clkc_periphs CLKID_TS>;
+				clock-names = "bus", "core";
+				power-domains = <&pwrc PWRC_T7_NNA_TOP_ID>;
+				#thermal-sensor-cells = <0>;
+				amlogic,secure-monitor = <&sm 4>;
+			};
+
+			vpu_tsensor: temperature-sensor@98000 {
+				compatible = "amlogic,t7-thermal";
+				reg = <0x0 0x98000 0x0 0x50>;
+				interrupts = <GIC_SPI 85 IRQ_TYPE_LEVEL_HIGH>;
+				clocks = <&clkc_periphs CLKID_SYS_TS_VPU>, <&clkc_periphs CLKID_TS>;
+				clock-names = "bus", "core";
+				power-domains = <&pwrc PWRC_T7_VPU_HDMI_ID>;
+				#thermal-sensor-cells = <0>;
+				amlogic,secure-monitor = <&sm 6>;
+			};
+
+			hevc_tsensor: temperature-sensor@9a000 {
+				compatible = "amlogic,t7-thermal";
+				reg = <0x0 0x9a000 0x0 0x50>;
+				interrupts = <GIC_SPI 86 IRQ_TYPE_LEVEL_HIGH>;
+				clocks =
+					<&clkc_periphs CLKID_SYS_TS_HEVC>,
+					<&clkc_periphs CLKID_TS>;
+				clock-names = "bus", "core";
+				power-domains = <&pwrc PWRC_T7_DOS_HEVC_ID>;
+				#thermal-sensor-cells = <0>;
+				amlogic,secure-monitor = <&sm 5>;
+			};
 		};
 
 	};

-- 
2.49.0



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[PATCH v7 3/4] arm64: dts: amlogic: t7: Add thermal zones

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Add thermal zones for all six sensors: a53, a73, gpu, nna, vpu, and hevc.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi | 179 ++++++++++++++++++++++++++++
 1 file changed, 179 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
index c81632d3984e8..52e106d931db0 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
@@ -9,6 +9,7 @@
 #include <dt-bindings/clock/amlogic,t7-scmi.h>
 #include <dt-bindings/clock/amlogic,t7-pll-clkc.h>
 #include <dt-bindings/clock/amlogic,t7-peripherals-clkc.h>
+#include <dt-bindings/thermal/thermal.h>
 
 / {
 	interrupt-parent = <&gic>;
@@ -885,6 +886,184 @@ hevc_tsensor: temperature-sensor@9a000 {
 				amlogic,secure-monitor = <&sm 5>;
 			};
 		};
+	};
+
+	thermal-zones {
+		a53_thermal: a53-thermal {
+			polling-delay = <1000>;
+			polling-delay-passive = <100>;
+			thermal-sensors = <&a53_tsensor>;
+
+			trips {
+				a53_passive: a53-passive {
+					temperature = <85000>; /* millicelsius */
+					hysteresis = <2000>; /* millicelsius */
+					type = "passive";
+				};
+
+				a53_hot: a53-hot {
+					temperature = <95000>; /* millicelsius */
+					hysteresis = <2000>; /* millicelsius */
+					type = "hot";
+				};
+
+				a53_critical: a53-critical {
+					temperature = <110000>; /* millicelsius */
+					hysteresis = <2000>; /* millicelsius */
+					type = "critical";
+				};
+			};
+
+			cooling-maps {
+				map-a53 {
+					trip = <&a53_passive>;
+					cooling-device =
+						<&cpu100 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+						<&cpu101 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+						<&cpu102 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+						<&cpu103 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+				};
+			};
+		};
+
+		a73_thermal: a73-thermal {
+			polling-delay = <1000>;
+			polling-delay-passive = <100>;
+			thermal-sensors = <&a73_tsensor>;
+
+			trips {
+				a73_passive: a73-passive {
+					temperature = <85000>; /* millicelsius */
+					hysteresis = <2000>; /* millicelsius */
+					type = "passive";
+				};
 
+				a73_hot: a73-hot {
+					temperature = <95000>; /* millicelsius */
+					hysteresis = <2000>; /* millicelsius */
+					type = "hot";
+				};
+
+				a73_critical: a73-critical {
+					temperature = <110000>; /* millicelsius */
+					hysteresis = <2000>; /* millicelsius */
+					type = "critical";
+				};
+			};
+
+			cooling-maps {
+				map-a73 {
+					trip = <&a73_passive>;
+					cooling-device = <&cpu0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&cpu1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&cpu2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
+							 <&cpu3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
+				};
+			};
+		};
+
+		gpu_thermal: gpu-thermal {
+			polling-delay = <1000>;
+			polling-delay-passive = <100>;
+			thermal-sensors = <&gpu_tsensor>;
+
+			trips {
+				gpu_passive: gpu-passive {
+					temperature = <95000>;
+					hysteresis = <5000>;
+					type = "passive";
+				};
+
+				gpu_hot: gpu-hot {
+					temperature = <105000>;
+					hysteresis = <5000>;
+					type = "hot";
+				};
+
+				gpu_critical: gpu-critical {
+					temperature = <115000>;
+					hysteresis = <1000>;
+					type = "critical";
+				};
+			};
+		};
+
+		hevc_thermal: hevc-thermal {
+			polling-delay = <1000>;
+			polling-delay-passive = <100>;
+			thermal-sensors = <&hevc_tsensor>;
+
+			trips {
+				hevc_passive: hevc-passive {
+					temperature = <95000>;
+					hysteresis = <5000>;
+					type = "passive";
+				};
+
+				hevc_hot: hevc-hot {
+					temperature = <105000>;
+					hysteresis = <5000>;
+					type = "hot";
+				};
+
+				hevc_critical: hevc-critical {
+					temperature = <115000>;
+					hysteresis = <1000>;
+					type = "critical";
+				};
+			};
+		};
+
+		nna_thermal: nna-thermal {
+			polling-delay = <1000>;
+			polling-delay-passive = <100>;
+			thermal-sensors = <&nna_tsensor>;
+
+			trips {
+				nna_passive: nna-passive {
+					temperature = <95000>;
+					hysteresis = <5000>;
+					type = "passive";
+				};
+
+				nna_hot: nna-hot {
+					temperature = <105000>;
+					hysteresis = <5000>;
+					type = "hot";
+				};
+
+				nna_critical: nna-critical {
+					temperature = <115000>;
+					hysteresis = <1000>;
+					type = "critical";
+				};
+			};
+		};
+
+		vpu_thermal: vpu-thermal {
+			polling-delay = <1000>;
+			polling-delay-passive = <100>;
+			thermal-sensors = <&vpu_tsensor>;
+
+			trips {
+				vpu_passive: vpu-passive {
+					temperature = <95000>;
+					hysteresis = <5000>;
+					type = "passive";
+				};
+
+				vpu_hot: vpu-hot {
+					temperature = <105000>;
+					hysteresis = <5000>;
+					type = "hot";
+				};
+
+				vpu_critical: vpu-critical {
+					temperature = <115000>;
+					hysteresis = <1000>;
+					type = "critical";
+				};
+			};
+		};
 	};
 };

-- 
2.49.0



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[PATCH v7 4/4] arm64: dts: amlogic: t7: khadas-vim4: Add fan cooling to thermal zones

[Ronald Claveau via B4 Relay]

From: Ronald Claveau <linux-kernel-dev@aliel.fr>

Add an active trip at 50°C to all six thermal zones and map it to the
khadas_mcu fan controller, using cooling states 1 to 5.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Ronald Claveau <linux-kernel-dev@aliel.fr>
---
 .../dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts  | 102 +++++++++++++++++++++
 1 file changed, 102 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
index 0fa83362b4179..91f81f7949bf8 100644
--- a/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
+++ b/arch/arm64/boot/dts/amlogic/amlogic-t7-a311d2-khadas-vim4.dts
@@ -256,6 +256,74 @@ xtal: xtal-clk {
 	};
 };
 
+&a53_thermal {
+	trips {
+		a53_active: a53-active {
+			temperature = <50000>; /* millicelsius */
+			hysteresis = <2000>; /* millicelsius */
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map {
+			trip = <&a53_active>;
+			cooling-device = <&khadas_mcu 1 5>;
+		};
+	};
+};
+
+&a73_thermal {
+	trips {
+		a73_active: a73-active {
+			temperature = <50000>; /* millicelsius */
+			hysteresis = <2000>; /* millicelsius */
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map {
+			trip = <&a73_active>;
+			cooling-device = <&khadas_mcu 1 5>;
+		};
+	};
+};
+
+&gpu_thermal {
+	trips {
+		gpu_active: gpu-active {
+			temperature = <50000>; /* millicelsius */
+			hysteresis = <2000>; /* millicelsius */
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map {
+			trip = <&gpu_active>;
+			cooling-device = <&khadas_mcu 1 5>;
+		};
+	};
+};
+
+&hevc_thermal {
+	trips {
+		hevc_active: hevc-active {
+			temperature = <50000>; /* millicelsius */
+			hysteresis = <2000>; /* millicelsius */
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map {
+			trip = <&hevc_active>;
+			cooling-device = <&khadas_mcu 1 5>;
+		};
+	};
+};
+
 &i2c_m_ao_a {
 	status = "okay";
 	pinctrl-0 = <&i2c0_ao_d_pins>;
@@ -269,6 +337,23 @@ khadas_mcu: system-controller@18 {
 	};
 };
 
+&nna_thermal {
+	trips {
+		nna_active: nna-active {
+			temperature = <50000>; /* millicelsius */
+			hysteresis = <2000>; /* millicelsius */
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map {
+			trip = <&nna_active>;
+			cooling-device = <&khadas_mcu 1 5>;
+		};
+	};
+};
+
 &pwm_ab {
 	status = "okay";
 	pinctrl-0 = <&pwm_a_pins>;
@@ -389,3 +474,20 @@ &uart_a {
 	clocks = <&xtal>, <&clkc_periphs CLKID_SYS_UART_A>, <&xtal>;
 	clock-names = "xtal", "pclk", "baud";
 };
+
+&vpu_thermal {
+	trips {
+		vpu_active: vpu-active {
+			temperature = <50000>; /* millicelsius */
+			hysteresis = <2000>; /* millicelsius */
+			type = "active";
+		};
+	};
+
+	cooling-maps {
+		map {
+			trip = <&vpu_active>;
+			cooling-device = <&khadas_mcu 1 5>;
+		};
+	};
+};

-- 
2.49.0



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Re: [PATCH v7 2/4] arm64: dts: amlogic: t7: Add thermal sensor nodes

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] thermal: amlogic: system hang due to MMIO access before clock enable
--

commit d943dedd550441fdf5ee6b1eb6eb97f02aac1ef7
Author: Ronald Claveau <linux-kernel-dev@aliel.fr>

arm64: dts: amlogic: t7: Add thermal sensor nodes

This commit adds six temperature sensor nodes to the device tree using
the amlogic,t7-thermal compatible. The nodes include references to their
required clocks and calibration data from the secure monitor.

> diff --git a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
> index 8aa85aab30469..c81632d3984e8 100644
> --- a/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
> +++ b/arch/arm64/boot/dts/amlogic/amlogic-t7.dtsi
> @@ -696,6 +696,26 @@ sec_ao: ao-secure@10220 {
>  				amlogic,has-chip-id;
>  			};
>  
> +			a73_tsensor: temperature-sensor@20000 {
> +				compatible = "amlogic,t7-thermal";
> +				reg = <0x0 0x20000 0x0 0x50>;
> +				interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
> +				clocks = <&clkc_periphs CLKID_SYS_TS_A73>, <&clkc_periphs CLKID_TS>;

[Severity: High]
Does adding this thermal sensor node expose an initialization order bug
in the driver that causes a system hang?

In drivers/thermal/amlogic_thermal.c:amlogic_thermal_probe(), the thermal
zone is registered before the hardware clocks are enabled:

	pdata->tzd = devm_thermal_of_zone_register(&pdev->dev,
						   0,
						   pdata,
						   &amlogic_thermal_ops);
	...
	ret = amlogic_thermal_enable(pdata);

During registration, the thermal core synchronously queries the temperature
via the driver's .get_temp callback (amlogic_thermal_get_temp()), which
performs an MMIO read via regmap_read() on TSENSOR_STAT0.

Since the driver enables the required peripheral clocks after the thermal
zone is registered, executing this MMIO read before the necessary bus clocks
are enabled will stall the AMBA bus and hang or reboot the system.

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261016-add-thermal-t7-vim4-v7-0-6eede5450fd4@aliel.fr?part=2

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