dt-bindings: thermal: Add support for Airoha EN7581 thermal sensor

Add support for Airoha EN7581 thermal sensor and monitor. This is a simple sensor for the CPU or SoC Package that provide thermal sensor and trip point for hot low and critical condition to fire interrupt and react on the abnormal state.

---
Changes v2:
- Add Reviewed-by tag

 .../thermal/airoha,en7581-thermal.yaml        | 48 +++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/airoha,en7581-thermal.yaml

new file mode 100644
index 000000000000..ca0242ef0378
@@ -0,0 +1,48 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/thermal/airoha,en7581-thermal.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Airoha EN7581 Thermal Sensor and Monitor
+
+maintainers:
+  - Christian Marangi <[email protected]>
+
+properties:
+  compatible:
+    const: airoha,en7581-thermal
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  airoha,chip-scu:
+    description: phandle to the chip SCU syscon
+    $ref: /schemas/types.yaml#/definitions/phandle
+
+  '#thermal-sensor-cells':
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - airoha,chip-scu
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    thermal-sensor@1efbd800 {
+        compatible = "airoha,en7581-thermal";
+        reg = <0x1efbd000 0xd5c>;
+        interrupts = <GIC_SPI 23 IRQ_TYPE_LEVEL_HIGH>;
+        airoha,chip-scu = <&chip_scu>;
+
+        #thermal-sensor-cells = <0>;
+    };

2.48.1

Add support for Airoha EN7581 thermal sensor. This provide support for reading the CPU or SoC Package sensor and to setup trip points for hot and critical condition. An interrupt is fired to react on this and doesn't require passive poll to read the temperature.

The thermal regs provide a way to read the ADC value from an external register placed in the Chip SCU regs. Monitor will read this value and fire an interrupt if the trip condition configured is reached.

The Thermal Trip and Interrupt logic is conceptually similar to Mediatek LVTS Thermal but differ in register mapping and actual function/bug workaround. The implementation only share some register names but from functionality observation it's very different and used only for the basic function of periodically poll the temp and trip the interrupt.

---
Changes v7:
- Fix compilation warning for switch case empty default Changes v6:
- Use minmax.h helper where possible
- Drop cast for void *
- Reset interrupt before calling update
- Improve logic for thermal temp read
Changes v5:
- Add additional info on difference from Mediatek LVTS driver Changes v4:
- Handle offset and slope in priv driver
Changes v3:
- Handle thermal_zone_device moved in different header
- Enable interrupt after thermal register
- Use new way to provide slope and offset
Changes v2:
- Add missing Makefile and Kconfig entry (somehow not included in v1)
- Sort include header
- Add missing bitfield.h

 drivers/thermal/Kconfig          |   9 +
 drivers/thermal/Makefile         |   1 +
 drivers/thermal/airoha_thermal.c | 489 +++++++++++++++++++++++++++++++
 3 files changed, 499 insertions(+)
 create mode 100644 drivers/thermal/airoha_thermal.c

index 510c2b821546..a09c188b9ad1 100644
@@ -327,6 +327,15 @@ config QORIQ_THERMAL
 	  cpufreq is used as the cooling device to throttle CPUs when the
 	  passive trip is crossed.
 
+config AIROHA_THERMAL
+	tristate "Airoha thermal sensor driver"
+	depends on ARCH_AIROHA || COMPILE_TEST
+	depends on MFD_SYSCON
+	depends on OF
+	help
+	  Enable this to plug the Airoha thermal sensor driver into the Linux
+	  thermal framework.
+
 config SPEAR_THERMAL
 	tristate "SPEAr thermal sensor driver"
 	depends on PLAT_SPEAR || COMPILE_TEST

index 9abf43a74f2b..d7718978db24 100644
@@ -38,6 +38,7 @@ obj-$(CONFIG_K3_THERMAL)	+= k3_bandgap.o k3_j72xx_bandgap.o
 # platform thermal drivers
 obj-y				+= broadcom/
 obj-$(CONFIG_THERMAL_MMIO)		+= thermal_mmio.o
+obj-$(CONFIG_AIROHA_THERMAL)	+= airoha_thermal.o
 obj-$(CONFIG_SPEAR_THERMAL)	+= spear_thermal.o
 obj-$(CONFIG_SUN8I_THERMAL)     += sun8i_thermal.o
 obj-$(CONFIG_ROCKCHIP_THERMAL)	+= rockchip_thermal.o

2.48.1

Applied, thanks!

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