[PATCH 0/2] thermal: loongson2: Add support for Loongson-2K0300 SoC

[PATCH 0/2] thermal: loongson2: Add support for Loongson-2K0300 SoC

[Binbin Zhou]

Hi all:

This patch series adds thermal zone support for the Loongson-2K0300 SoC.

The Loongson-2K0300's thermal sensor is generally compatible with the
existing Loongson-2K series, but it features several key differences:
1. It has an independent CPU ID register for reading chip version
information.
2. The raw temperature output field has been extended from 8 bits to 11
bits.
3. The temperature calculation formula has been updated to incorporate a
correction factor based on the version information.

To ensure robustness on older hardware revisions, a fallback mechanism
is included: if the calculated temperature falls outside the valid range
(-55 TO 125),  the driver falls back to a simpler calculation and prints
a warning.

The patches have been validated on the Loongson-2K0300 development board.

Thanks.
Binbin

Binbin Zhou (2):
  dt-bindings: thermal: loongson,ls2k-thermal: Add compatible for
    Loongson-2K0300
  thermal/drivers/loongson2: Add thermal driver support for
    Loongson-2K0300

 .../thermal/loongson,ls2k-thermal.yaml        | 68 +++++++++++----
 drivers/thermal/loongson2_thermal.c           | 83 +++++++++++++++++--
 2 files changed, 127 insertions(+), 24 deletions(-)


base-commit: 795f1b1a91ae13ebc012a364075e42f486a1cafe
-- 
2.52.0

[PATCH 1/2] dt-bindings: thermal: loongson,ls2k-thermal: Add compatible for Loongson-2K0300

[Binbin Zhou]

Add a new compatible string `loongson,ls2k0300-thermal` for the thermal
sensor found on the Loongson-2K0300 SoC.

The hardware differs from the existing SoCs in its register layout: it
requires two register regions (one for the thermal sensor control and
another for the CPU ID).

Update the binding to describe this new requirement.

Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
---
 .../thermal/loongson,ls2k-thermal.yaml        | 68 ++++++++++++++-----
 1 file changed, 50 insertions(+), 18 deletions(-)

diff --git a/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml b/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
index 79e691b08341..b5cbfd201105 100644
--- a/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
+++ b/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
@@ -10,13 +10,11 @@ maintainers:
   - zhanghongchen <zhanghongchen@loongson.cn>
   - Yinbo Zhu <zhuyinbo@loongson.cn>
 
-allOf:
-  - $ref: /schemas/thermal/thermal-sensor.yaml#
-
 properties:
   compatible:
     oneOf:
       - enum:
+          - loongson,ls2k0300-thermal
           - loongson,ls2k1000-thermal
           - loongson,ls2k2000-thermal
       - items:
@@ -39,23 +37,46 @@ required:
   - reg
   - interrupts
 
-if:
-  properties:
-    compatible:
-      contains:
-        enum:
-          - loongson,ls2k2000-thermal
+allOf:
+  - $ref: /schemas/thermal/thermal-sensor.yaml#
 
-then:
-  properties:
-    reg:
-      minItems: 2
-      maxItems: 2
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - loongson,ls2k0300-thermal
+    then:
+      properties:
+        reg:
+          items:
+            - description: Thermal base register region
+            - description: CPU ID register region
 
-else:
-  properties:
-    reg:
-      maxItems: 1
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - loongson,ls2k1000-thermal
+    then:
+      properties:
+        reg:
+          items:
+            - description: Thermal base register region
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - loongson,ls2k2000-thermal
+    then:
+      properties:
+        reg:
+          items:
+            - description: Thermal base register region
+            - description: Thermal data output register region
 
 unevaluatedProperties: false
 
@@ -69,3 +90,14 @@ examples:
         interrupts = <7 IRQ_TYPE_LEVEL_LOW>;
         #thermal-sensor-cells = <1>;
     };
+
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    thermal-sensor@16001500 {
+       compatible = "loongson,ls2k0300-thermal";
+       reg = <0x16001500 0x30>,
+             <0x16003ff0 0x8>;
+       interrupt-parent = <&liointc1>;
+       interrupts = <20 IRQ_TYPE_LEVEL_HIGH>;
+       #thermal-sensor-cells = <1>;
+    };
-- 
2.52.0

Re: [PATCH 1/2] dt-bindings: thermal: loongson,ls2k-thermal: Add compatible for Loongson-2K0300

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 3601 bytes --]

On Fri, Jul 10, 2026 at 04:24:59PM +0800, Binbin Zhou wrote:
> Add a new compatible string `loongson,ls2k0300-thermal` for the thermal
> sensor found on the Loongson-2K0300 SoC.
> 
> The hardware differs from the existing SoCs in its register layout: it
> requires two register regions (one for the thermal sensor control and
> another for the CPU ID).
> 
> Update the binding to describe this new requirement.
> 
> Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> ---
>  .../thermal/loongson,ls2k-thermal.yaml        | 68 ++++++++++++++-----
>  1 file changed, 50 insertions(+), 18 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml b/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> index 79e691b08341..b5cbfd201105 100644
> --- a/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> +++ b/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> @@ -10,13 +10,11 @@ maintainers:
>    - zhanghongchen <zhanghongchen@loongson.cn>
>    - Yinbo Zhu <zhuyinbo@loongson.cn>
>  
> -allOf:
> -  - $ref: /schemas/thermal/thermal-sensor.yaml#
> -
>  properties:
>    compatible:
>      oneOf:
>        - enum:
> +          - loongson,ls2k0300-thermal
>            - loongson,ls2k1000-thermal
>            - loongson,ls2k2000-thermal
>        - items:
> @@ -39,23 +37,46 @@ required:
>    - reg
>    - interrupts
>  
> -if:
> -  properties:
> -    compatible:
> -      contains:
> -        enum:
> -          - loongson,ls2k2000-thermal
> +allOf:
> +  - $ref: /schemas/thermal/thermal-sensor.yaml#
>  
> -then:
> -  properties:
> -    reg:
> -      minItems: 2
> -      maxItems: 2
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - loongson,ls2k0300-thermal
> +    then:
> +      properties:
> +        reg:
> +          items:
> +            - description: Thermal base register region
> +            - description: CPU ID register region
>  
> -else:
> -  properties:
> -    reg:
> -      maxItems: 1
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - loongson,ls2k1000-thermal
> +    then:
> +      properties:
> +        reg:
> +          items:
> +            - description: Thermal base register region
> +
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            enum:
> +              - loongson,ls2k2000-thermal
> +    then:
> +      properties:
> +        reg:
> +          items:
> +            - description: Thermal base register region
> +            - description: Thermal data output register region
>  
>  unevaluatedProperties: false
>  
> @@ -69,3 +90,14 @@ examples:
>          interrupts = <7 IRQ_TYPE_LEVEL_LOW>;
>          #thermal-sensor-cells = <1>;
>      };
> +
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    thermal-sensor@16001500 {
> +       compatible = "loongson,ls2k0300-thermal";
> +       reg = <0x16001500 0x30>,
> +             <0x16003ff0 0x8>;

Quite frankly, the address and size of this look like the second
register region here is actually a few bytes in a syscon that is being
misrepresented.
What lies at the addresses immediately before and after 0x16003ff0?


Thanks,
Conor.

> +       interrupt-parent = <&liointc1>;
> +       interrupts = <20 IRQ_TYPE_LEVEL_HIGH>;
> +       #thermal-sensor-cells = <1>;
> +    };
> -- 
> 2.52.0
> 

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Re: [PATCH 1/2] dt-bindings: thermal: loongson,ls2k-thermal: Add compatible for Loongson-2K0300

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 4068 bytes --]

On Fri, Jul 10, 2026 at 05:21:22PM +0100, Conor Dooley wrote:
> On Fri, Jul 10, 2026 at 04:24:59PM +0800, Binbin Zhou wrote:
> > Add a new compatible string `loongson,ls2k0300-thermal` for the thermal
> > sensor found on the Loongson-2K0300 SoC.
> > 
> > The hardware differs from the existing SoCs in its register layout: it
> > requires two register regions (one for the thermal sensor control and
> > another for the CPU ID).
> > 
> > Update the binding to describe this new requirement.
> > 
> > Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> > ---
> >  .../thermal/loongson,ls2k-thermal.yaml        | 68 ++++++++++++++-----
> >  1 file changed, 50 insertions(+), 18 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml b/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> > index 79e691b08341..b5cbfd201105 100644
> > --- a/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> > +++ b/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> > @@ -10,13 +10,11 @@ maintainers:
> >    - zhanghongchen <zhanghongchen@loongson.cn>
> >    - Yinbo Zhu <zhuyinbo@loongson.cn>
> >  
> > -allOf:
> > -  - $ref: /schemas/thermal/thermal-sensor.yaml#
> > -
> >  properties:
> >    compatible:
> >      oneOf:
> >        - enum:
> > +          - loongson,ls2k0300-thermal
> >            - loongson,ls2k1000-thermal
> >            - loongson,ls2k2000-thermal
> >        - items:
> > @@ -39,23 +37,46 @@ required:
> >    - reg
> >    - interrupts
> >  
> > -if:
> > -  properties:
> > -    compatible:
> > -      contains:
> > -        enum:
> > -          - loongson,ls2k2000-thermal
> > +allOf:
> > +  - $ref: /schemas/thermal/thermal-sensor.yaml#
> >  
> > -then:
> > -  properties:
> > -    reg:
> > -      minItems: 2
> > -      maxItems: 2
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - loongson,ls2k0300-thermal
> > +    then:
> > +      properties:
> > +        reg:
> > +          items:
> > +            - description: Thermal base register region
> > +            - description: CPU ID register region
> >  
> > -else:
> > -  properties:
> > -    reg:
> > -      maxItems: 1
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - loongson,ls2k1000-thermal
> > +    then:
> > +      properties:
> > +        reg:
> > +          items:
> > +            - description: Thermal base register region
> > +
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - loongson,ls2k2000-thermal
> > +    then:
> > +      properties:
> > +        reg:
> > +          items:
> > +            - description: Thermal base register region
> > +            - description: Thermal data output register region
> >  
> >  unevaluatedProperties: false
> >  
> > @@ -69,3 +90,14 @@ examples:
> >          interrupts = <7 IRQ_TYPE_LEVEL_LOW>;
> >          #thermal-sensor-cells = <1>;
> >      };
> > +
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    thermal-sensor@16001500 {
> > +       compatible = "loongson,ls2k0300-thermal";
> > +       reg = <0x16001500 0x30>,
> > +             <0x16003ff0 0x8>;
> 
> Quite frankly, the address and size of this look like the second
> register region here is actually a few bytes in a syscon that is being
> misrepresented.
> What lies at the addresses immediately before and after 0x16003ff0?

Hmm, I just realised that the new device is the 0300, making this second
reg property the "cpuid" region. That makes this doubly suspect looking.

> 
> 
> Thanks,
> Conor.
> 
> > +       interrupt-parent = <&liointc1>;
> > +       interrupts = <20 IRQ_TYPE_LEVEL_HIGH>;
> > +       #thermal-sensor-cells = <1>;
> > +    };
> > -- 
> > 2.52.0
> > 



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Re: [PATCH 1/2] dt-bindings: thermal: loongson,ls2k-thermal: Add compatible for Loongson-2K0300

[Binbin Zhou]

Hi Conor:

Thanks for your reply.

On Sat, Jul 11, 2026 at 12:21 AM Conor Dooley <conor@kernel.org> wrote:
>
> On Fri, Jul 10, 2026 at 04:24:59PM +0800, Binbin Zhou wrote:
> > Add a new compatible string `loongson,ls2k0300-thermal` for the thermal
> > sensor found on the Loongson-2K0300 SoC.
> >
> > The hardware differs from the existing SoCs in its register layout: it
> > requires two register regions (one for the thermal sensor control and
> > another for the CPU ID).
> >
> > Update the binding to describe this new requirement.
> >
> > Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> > ---
> >  .../thermal/loongson,ls2k-thermal.yaml        | 68 ++++++++++++++-----
> >  1 file changed, 50 insertions(+), 18 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml b/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> > index 79e691b08341..b5cbfd201105 100644
> > --- a/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> > +++ b/Documentation/devicetree/bindings/thermal/loongson,ls2k-thermal.yaml
> > @@ -10,13 +10,11 @@ maintainers:
> >    - zhanghongchen <zhanghongchen@loongson.cn>
> >    - Yinbo Zhu <zhuyinbo@loongson.cn>
> >
> > -allOf:
> > -  - $ref: /schemas/thermal/thermal-sensor.yaml#
> > -
> >  properties:
> >    compatible:
> >      oneOf:
> >        - enum:
> > +          - loongson,ls2k0300-thermal
> >            - loongson,ls2k1000-thermal
> >            - loongson,ls2k2000-thermal
> >        - items:
> > @@ -39,23 +37,46 @@ required:
> >    - reg
> >    - interrupts
> >
> > -if:
> > -  properties:
> > -    compatible:
> > -      contains:
> > -        enum:
> > -          - loongson,ls2k2000-thermal
> > +allOf:
> > +  - $ref: /schemas/thermal/thermal-sensor.yaml#
> >
> > -then:
> > -  properties:
> > -    reg:
> > -      minItems: 2
> > -      maxItems: 2
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - loongson,ls2k0300-thermal
> > +    then:
> > +      properties:
> > +        reg:
> > +          items:
> > +            - description: Thermal base register region
> > +            - description: CPU ID register region
> >
> > -else:
> > -  properties:
> > -    reg:
> > -      maxItems: 1
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - loongson,ls2k1000-thermal
> > +    then:
> > +      properties:
> > +        reg:
> > +          items:
> > +            - description: Thermal base register region
> > +
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          contains:
> > +            enum:
> > +              - loongson,ls2k2000-thermal
> > +    then:
> > +      properties:
> > +        reg:
> > +          items:
> > +            - description: Thermal base register region
> > +            - description: Thermal data output register region
> >
> >  unevaluatedProperties: false
> >
> > @@ -69,3 +90,14 @@ examples:
> >          interrupts = <7 IRQ_TYPE_LEVEL_LOW>;
> >          #thermal-sensor-cells = <1>;
> >      };
> > +
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    thermal-sensor@16001500 {
> > +       compatible = "loongson,ls2k0300-thermal";
> > +       reg = <0x16001500 0x30>,
> > +             <0x16003ff0 0x8>;
>
> Quite frankly, the address and size of this look like the second
> register region here is actually a few bytes in a syscon that is being
> misrepresented.
> What lies at the addresses immediately before and after 0x16003ff0?

Yes, it can be viewed as part of the system configuration registers,
which appear somewhat disorganized. Within this section,
0x16003fe0–0x16003ffc represents eight chip ID registers.

0x16003fe0 --> the 4th chip id
0x16003fe4 --> the 5th chip id
0x16003fe8 --> the 6th chip id
0x16003fec --> the 7th chip id
0x16003ff0 --> the 0th chip id
0x16003ff4 --> the 1st chip id
0x16003ff8 --> the 2nd chip id
0x16003ffc --> the 3rd chip id

Perhaps I shouldn’t have referenced `0x16003ff0` separately here. It
would be more reasonable to declare the entire chip ID address space
as a separate syscon and have it referenced by thermal driver.

For example:

In DTS{i}:
chipid_syscon: syscon@16003fe0 {
       compatible = “loongson,ls2k0300-cphipid-syscon”, “syscon”;
       reg = <0x0 0x16003fe0 0x0 0x20>;
};

In thermal driver:
Use
`syscon_regmap_lookup_by_phandle(np, "loongson,chipid"); `
Or:
`syscon_regmap_lookup_by_compatible("loongson,ls2k0300-cphipid-syscon");`

get the chip id address space.

>
>
> Thanks,
> Conor.
>
> > +       interrupt-parent = <&liointc1>;
> > +       interrupts = <20 IRQ_TYPE_LEVEL_HIGH>;
> > +       #thermal-sensor-cells = <1>;
> > +    };
> > --
> > 2.52.0
> >

-- 
Thanks.
Binbin

[PATCH 2/2] thermal/drivers/loongson2: Add thermal driver support for Loongson-2K0300

[Binbin Zhou]

The Loongson-2K0300 SoC uses a new thermal sensor that requires reading
a separate CPU ID register to obtain hardware version information. This
version info is used as a correction factor (fix_data) in the
temperature calculation formula.

Its thermal sensor requires the following hardware-specific handling:
 - Read chip ID register (offset 0x0 and 0x4) to get the compensation
   value (comp_val). The value is stored in either bits [31:20] of the
   ID0 register or bits [15:0] of the ID1 register, depending on the
   EXTERN_ID bit.

 - The compensation value is a signed 15-bit field; extract the value
   and apply sign accordingly.

Additionally, some early Loongson-2K0300 chips may have an old fuse that
yields invalid temperature readings outside the -55 to 125 range. In
such cases, the driver falls back to a simplified formula (raw * 569 -
394700) and logs a warning, ensuring the system can still function
without crashing.

Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
---
 drivers/thermal/loongson2_thermal.c | 83 ++++++++++++++++++++++++++---
 1 file changed, 77 insertions(+), 6 deletions(-)

diff --git a/drivers/thermal/loongson2_thermal.c b/drivers/thermal/loongson2_thermal.c
index ea4dd2fb1f47..a7eb87070aa9 100644
--- a/drivers/thermal/loongson2_thermal.c
+++ b/drivers/thermal/loongson2_thermal.c
@@ -2,9 +2,11 @@
 /*
  * Author: zhanghongchen <zhanghongchen@loongson.cn>
  *         Yinbo Zhu <zhuyinbo@loongson.cn>
- * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
+ *         Binbin Zhou <zhoubinbin@loongson.cn>
+ * Copyright (C) 2022-2026 Loongson Technology Corporation Limited
  */
 
+#include <linux/bitfield.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/minmax.h>
@@ -23,27 +25,44 @@
 #define LOONGSON2_THSENS_CTRL_LOW_REG	0x8
 #define LOONGSON2_THSENS_STATUS_REG	0x10
 #define LOONGSON2_THSENS_OUT_REG	0x14
+#define LOONGSON2_THSENS_CFG_REG	0x18
 
 #define LOONGSON2_THSENS_INT_LO		BIT(0)
 #define LOONGSON2_THSENS_INT_HIGH	BIT(1)
 #define LOONGSON2_THSENS_INT_EN		(LOONGSON2_THSENS_INT_LO | \
 					 LOONGSON2_THSENS_INT_HIGH)
 #define LOONGSON2_THSENS_OUT_MASK	0xFF
+#define LS2K0300_THSENS_OUT_MASK	GENMASK(10, 0)
+
+#define LS2K0300_CHIP_ID1		0x4
+#define LS2K0300_EXTERN_ID		BIT(4)
+#define LS2K0300_ID0_VAL_MASK		GENMASK(31, 20)
+#define LS2K0300_ID1_VAL_MASK		GENMASK(15, 0)
+
+#define LS2K0300_COMP_VAL_MASK		GENMASK(14, 0)
+#define LS2K0300_COMP_SIGN_BIT		BIT(15)
+
+#define LS2K0300_LOWEST_VALID_TEMP	(-55000)
+#define LS2K0300_HIGHEST_VALID_TEMP	(125000)
 
 /*
  * This flag is used to indicate the temperature reading
  * method of the Loongson-2K2000
  */
 #define LS2K2000_THSENS_OUT_FLAG	BIT(0)
+#define LS2K0300_CHIP_ID_FLAG		BIT(1)
 
 struct loongson2_thermal_chip_data {
 	unsigned int thermal_sensor_sel;
 	unsigned int flags;
+	const struct thermal_zone_device_ops *thermal_ops;
 };
 
 struct loongson2_thermal_data {
+	struct device *dev;
 	void __iomem *ctrl_reg;
 	void __iomem *temp_reg;
+	void __iomem *id_reg;
 	const struct loongson2_thermal_chip_data *chip_data;
 };
 
@@ -71,6 +90,38 @@ static int loongson2_thermal_set(struct loongson2_thermal_data *data,
 	return 0;
 }
 
+static int loongson2_2k0300_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	struct loongson2_thermal_data *tdata = thermal_zone_device_priv(tz);
+	int calib_data, calib_offset, temp_mc, raw_adc;
+	u32 chip_id0, chip_id1;
+
+	raw_adc = FIELD_GET(LS2K0300_THSENS_OUT_MASK,
+			    readl(tdata->ctrl_reg + LOONGSON2_THSENS_OUT_REG));
+	chip_id0 = readl(tdata->id_reg);
+	chip_id1 = readl(tdata->id_reg + LS2K0300_CHIP_ID1);
+
+	if (chip_id0 & LS2K0300_EXTERN_ID)
+		calib_data = FIELD_GET(LS2K0300_ID1_VAL_MASK, chip_id1);
+	else
+		calib_data = FIELD_GET(LS2K0300_ID0_VAL_MASK, chip_id0);
+
+	calib_offset = FIELD_GET(LS2K0300_COMP_VAL_MASK, calib_data);
+	if (calib_data & LS2K0300_COMP_SIGN_BIT)
+		calib_offset = -calib_offset;
+
+	temp_mc = (raw_adc + calib_offset) * 570 - 394700;
+
+	/* For old fuse which can not read right thermal data */
+	if (temp_mc < LS2K0300_LOWEST_VALID_TEMP || temp_mc > LS2K0300_HIGHEST_VALID_TEMP) {
+		dev_warn_once(tdata->dev, "It's an old fuse, thermal %d is not right\n", temp_mc);
+		temp_mc = raw_adc * 569 - 394700;
+	}
+	*temp = temp_mc;
+
+	return 0;
+}
+
 static int loongson2_2k1000_get_temp(struct thermal_zone_device *tz, int *temp)
 {
 	int val;
@@ -112,6 +163,11 @@ static int loongson2_thermal_set_trips(struct thermal_zone_device *tz, int low,
 	return loongson2_thermal_set(data, low/MILLI, high/MILLI, true);
 }
 
+static const struct thermal_zone_device_ops loongson2_2k0300_of_thermal_ops = {
+	.get_temp = loongson2_2k0300_get_temp,
+	.set_trips = loongson2_thermal_set_trips,
+};
+
 static const struct thermal_zone_device_ops loongson2_2k1000_of_thermal_ops = {
 	.get_temp = loongson2_2k1000_get_temp,
 	.set_trips = loongson2_thermal_set_trips,
@@ -124,7 +180,6 @@ static const struct thermal_zone_device_ops loongson2_2k2000_of_thermal_ops = {
 
 static int loongson2_thermal_probe(struct platform_device *pdev)
 {
-	const struct thermal_zone_device_ops *thermal_ops;
 	struct device *dev = &pdev->dev;
 	struct loongson2_thermal_data *data;
 	struct thermal_zone_device *tzd;
@@ -134,6 +189,7 @@ static int loongson2_thermal_probe(struct platform_device *pdev)
 	if (!data)
 		return -ENOMEM;
 
+	data->dev = dev;
 	data->chip_data = device_get_match_data(dev);
 
 	data->ctrl_reg = devm_platform_ioremap_resource(pdev, 0);
@@ -145,10 +201,13 @@ static int loongson2_thermal_probe(struct platform_device *pdev)
 		data->temp_reg = devm_platform_ioremap_resource(pdev, 1);
 		if (IS_ERR(data->temp_reg))
 			return PTR_ERR(data->temp_reg);
+	}
 
-		thermal_ops = &loongson2_2k2000_of_thermal_ops;
-	} else {
-		thermal_ops = &loongson2_2k1000_of_thermal_ops;
+	/* The chip id register is needed for Loongson-2K0300 */
+	if (data->chip_data->flags & LS2K0300_CHIP_ID_FLAG) {
+		data->id_reg = devm_platform_ioremap_resource(pdev, 1);
+		if (IS_ERR(data->id_reg))
+			return PTR_ERR(data->id_reg);
 	}
 
 	irq = platform_get_irq(pdev, 0);
@@ -160,7 +219,7 @@ static int loongson2_thermal_probe(struct platform_device *pdev)
 	loongson2_thermal_set(data, 0, 0, false);
 
 	for (i = 0; i <= LOONGSON2_MAX_SENSOR_SEL_NUM; i++) {
-		tzd = devm_thermal_of_zone_register(dev, i, data, thermal_ops);
+		tzd = devm_thermal_of_zone_register(dev, i, data, data->chip_data->thermal_ops);
 
 		if (!IS_ERR(tzd))
 			break;
@@ -181,17 +240,29 @@ static int loongson2_thermal_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct loongson2_thermal_chip_data loongson2_thermal_ls2k0300_data = {
+	.thermal_sensor_sel = 0,
+	.flags = LS2K0300_CHIP_ID_FLAG,
+	.thermal_ops = &loongson2_2k0300_of_thermal_ops,
+};
+
 static const struct loongson2_thermal_chip_data loongson2_thermal_ls2k1000_data = {
 	.thermal_sensor_sel = 0,
 	.flags = 0,
+	.thermal_ops = &loongson2_2k1000_of_thermal_ops,
 };
 
 static const struct loongson2_thermal_chip_data loongson2_thermal_ls2k2000_data = {
 	.thermal_sensor_sel = 0,
 	.flags = LS2K2000_THSENS_OUT_FLAG,
+	.thermal_ops = &loongson2_2k2000_of_thermal_ops,
 };
 
 static const struct of_device_id of_loongson2_thermal_match[] = {
+	{
+		.compatible = "loongson,ls2k0300-thermal",
+		.data = &loongson2_thermal_ls2k0300_data,
+	},
 	{
 		.compatible = "loongson,ls2k1000-thermal",
 		.data = &loongson2_thermal_ls2k1000_data,
-- 
2.52.0

Re: [PATCH 2/2] thermal/drivers/loongson2: Add thermal driver support for Loongson-2K0300

[Huacai Chen]

Hi, Binbin,

On Fri, Jul 10, 2026 at 4:25 PM Binbin Zhou <zhoubinbin@loongson.cn> wrote:
>
> The Loongson-2K0300 SoC uses a new thermal sensor that requires reading
> a separate CPU ID register to obtain hardware version information. This
> version info is used as a correction factor (fix_data) in the
> temperature calculation formula.
>
> Its thermal sensor requires the following hardware-specific handling:
>  - Read chip ID register (offset 0x0 and 0x4) to get the compensation
>    value (comp_val). The value is stored in either bits [31:20] of the
>    ID0 register or bits [15:0] of the ID1 register, depending on the
>    EXTERN_ID bit.
>
>  - The compensation value is a signed 15-bit field; extract the value
>    and apply sign accordingly.
>
> Additionally, some early Loongson-2K0300 chips may have an old fuse that
> yields invalid temperature readings outside the -55 to 125 range. In
> such cases, the driver falls back to a simplified formula (raw * 569 -
> 394700) and logs a warning, ensuring the system can still function
> without crashing.
>
> Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
> ---
>  drivers/thermal/loongson2_thermal.c | 83 ++++++++++++++++++++++++++---
>  1 file changed, 77 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/thermal/loongson2_thermal.c b/drivers/thermal/loongson2_thermal.c
> index ea4dd2fb1f47..a7eb87070aa9 100644
> --- a/drivers/thermal/loongson2_thermal.c
> +++ b/drivers/thermal/loongson2_thermal.c
> @@ -2,9 +2,11 @@
>  /*
>   * Author: zhanghongchen <zhanghongchen@loongson.cn>
>   *         Yinbo Zhu <zhuyinbo@loongson.cn>
> - * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
> + *         Binbin Zhou <zhoubinbin@loongson.cn>
> + * Copyright (C) 2022-2026 Loongson Technology Corporation Limited
>   */
>
> +#include <linux/bitfield.h>
>  #include <linux/interrupt.h>
>  #include <linux/io.h>
>  #include <linux/minmax.h>
> @@ -23,27 +25,44 @@
>  #define LOONGSON2_THSENS_CTRL_LOW_REG  0x8
>  #define LOONGSON2_THSENS_STATUS_REG    0x10
>  #define LOONGSON2_THSENS_OUT_REG       0x14
> +#define LOONGSON2_THSENS_CFG_REG       0x18
>
>  #define LOONGSON2_THSENS_INT_LO                BIT(0)
>  #define LOONGSON2_THSENS_INT_HIGH      BIT(1)
>  #define LOONGSON2_THSENS_INT_EN                (LOONGSON2_THSENS_INT_LO | \
>                                          LOONGSON2_THSENS_INT_HIGH)
>  #define LOONGSON2_THSENS_OUT_MASK      0xFF
> +#define LS2K0300_THSENS_OUT_MASK       GENMASK(10, 0)
The naming is a little strange, maybe use LOONGSON2_THSENS_OUT_8B_MASK
and LOONGSON2_THSENS_OUT_10B_MASK?

> +
> +#define LS2K0300_CHIP_ID1              0x4
Also define LS2K0300_CHIP_ID0 here?

> +#define LS2K0300_EXTERN_ID             BIT(4)
> +#define LS2K0300_ID0_VAL_MASK          GENMASK(31, 20)
> +#define LS2K0300_ID1_VAL_MASK          GENMASK(15, 0)
> +
> +#define LS2K0300_COMP_VAL_MASK         GENMASK(14, 0)
> +#define LS2K0300_COMP_SIGN_BIT         BIT(15)
> +
> +#define LS2K0300_LOWEST_VALID_TEMP     (-55000)
> +#define LS2K0300_HIGHEST_VALID_TEMP    (125000)
>
>  /*
>   * This flag is used to indicate the temperature reading
>   * method of the Loongson-2K2000
>   */
>  #define LS2K2000_THSENS_OUT_FLAG       BIT(0)
> +#define LS2K0300_CHIP_ID_FLAG          BIT(1)
>
>  struct loongson2_thermal_chip_data {
>         unsigned int thermal_sensor_sel;
>         unsigned int flags;
> +       const struct thermal_zone_device_ops *thermal_ops;
>  };
>
>  struct loongson2_thermal_data {
> +       struct device *dev;
>         void __iomem *ctrl_reg;
>         void __iomem *temp_reg;
> +       void __iomem *id_reg;
>         const struct loongson2_thermal_chip_data *chip_data;
>  };
>
> @@ -71,6 +90,38 @@ static int loongson2_thermal_set(struct loongson2_thermal_data *data,
>         return 0;
>  }
>
> +static int loongson2_2k0300_get_temp(struct thermal_zone_device *tz, int *temp)
> +{
> +       struct loongson2_thermal_data *tdata = thermal_zone_device_priv(tz);
> +       int calib_data, calib_offset, temp_mc, raw_adc;
> +       u32 chip_id0, chip_id1;
> +
> +       raw_adc = FIELD_GET(LS2K0300_THSENS_OUT_MASK,
> +                           readl(tdata->ctrl_reg + LOONGSON2_THSENS_OUT_REG));
> +       chip_id0 = readl(tdata->id_reg);
> +       chip_id1 = readl(tdata->id_reg + LS2K0300_CHIP_ID1);
> +
> +       if (chip_id0 & LS2K0300_EXTERN_ID)
> +               calib_data = FIELD_GET(LS2K0300_ID1_VAL_MASK, chip_id1);
> +       else
> +               calib_data = FIELD_GET(LS2K0300_ID0_VAL_MASK, chip_id0);
> +
> +       calib_offset = FIELD_GET(LS2K0300_COMP_VAL_MASK, calib_data);
> +       if (calib_data & LS2K0300_COMP_SIGN_BIT)
> +               calib_offset = -calib_offset;
> +
> +       temp_mc = (raw_adc + calib_offset) * 570 - 394700;
> +
> +       /* For old fuse which can not read right thermal data */
> +       if (temp_mc < LS2K0300_LOWEST_VALID_TEMP || temp_mc > LS2K0300_HIGHEST_VALID_TEMP) {
Is there a better way to detect the old fuse? Because I think temp_mc
between LS2K0300_LOWEST_VALID_TEMP and  LS2K0300_HIGHEST_VALID_TEMP is
also not valid for the old fuse.

Huacai

> +               dev_warn_once(tdata->dev, "It's an old fuse, thermal %d is not right\n", temp_mc);
> +               temp_mc = raw_adc * 569 - 394700;
> +       }
> +       *temp = temp_mc;
> +
> +       return 0;
> +}
> +
>  static int loongson2_2k1000_get_temp(struct thermal_zone_device *tz, int *temp)
>  {
>         int val;
> @@ -112,6 +163,11 @@ static int loongson2_thermal_set_trips(struct thermal_zone_device *tz, int low,
>         return loongson2_thermal_set(data, low/MILLI, high/MILLI, true);
>  }
>
> +static const struct thermal_zone_device_ops loongson2_2k0300_of_thermal_ops = {
> +       .get_temp = loongson2_2k0300_get_temp,
> +       .set_trips = loongson2_thermal_set_trips,
> +};
> +
>  static const struct thermal_zone_device_ops loongson2_2k1000_of_thermal_ops = {
>         .get_temp = loongson2_2k1000_get_temp,
>         .set_trips = loongson2_thermal_set_trips,
> @@ -124,7 +180,6 @@ static const struct thermal_zone_device_ops loongson2_2k2000_of_thermal_ops = {
>
>  static int loongson2_thermal_probe(struct platform_device *pdev)
>  {
> -       const struct thermal_zone_device_ops *thermal_ops;
>         struct device *dev = &pdev->dev;
>         struct loongson2_thermal_data *data;
>         struct thermal_zone_device *tzd;
> @@ -134,6 +189,7 @@ static int loongson2_thermal_probe(struct platform_device *pdev)
>         if (!data)
>                 return -ENOMEM;
>
> +       data->dev = dev;
>         data->chip_data = device_get_match_data(dev);
>
>         data->ctrl_reg = devm_platform_ioremap_resource(pdev, 0);
> @@ -145,10 +201,13 @@ static int loongson2_thermal_probe(struct platform_device *pdev)
>                 data->temp_reg = devm_platform_ioremap_resource(pdev, 1);
>                 if (IS_ERR(data->temp_reg))
>                         return PTR_ERR(data->temp_reg);
> +       }
>
> -               thermal_ops = &loongson2_2k2000_of_thermal_ops;
> -       } else {
> -               thermal_ops = &loongson2_2k1000_of_thermal_ops;
> +       /* The chip id register is needed for Loongson-2K0300 */
> +       if (data->chip_data->flags & LS2K0300_CHIP_ID_FLAG) {
> +               data->id_reg = devm_platform_ioremap_resource(pdev, 1);
> +               if (IS_ERR(data->id_reg))
> +                       return PTR_ERR(data->id_reg);
>         }
>
>         irq = platform_get_irq(pdev, 0);
> @@ -160,7 +219,7 @@ static int loongson2_thermal_probe(struct platform_device *pdev)
>         loongson2_thermal_set(data, 0, 0, false);
>
>         for (i = 0; i <= LOONGSON2_MAX_SENSOR_SEL_NUM; i++) {
> -               tzd = devm_thermal_of_zone_register(dev, i, data, thermal_ops);
> +               tzd = devm_thermal_of_zone_register(dev, i, data, data->chip_data->thermal_ops);
>
>                 if (!IS_ERR(tzd))
>                         break;
> @@ -181,17 +240,29 @@ static int loongson2_thermal_probe(struct platform_device *pdev)
>         return 0;
>  }
>
> +static const struct loongson2_thermal_chip_data loongson2_thermal_ls2k0300_data = {
> +       .thermal_sensor_sel = 0,
> +       .flags = LS2K0300_CHIP_ID_FLAG,
> +       .thermal_ops = &loongson2_2k0300_of_thermal_ops,
> +};
> +
>  static const struct loongson2_thermal_chip_data loongson2_thermal_ls2k1000_data = {
>         .thermal_sensor_sel = 0,
>         .flags = 0,
> +       .thermal_ops = &loongson2_2k1000_of_thermal_ops,
>  };
>
>  static const struct loongson2_thermal_chip_data loongson2_thermal_ls2k2000_data = {
>         .thermal_sensor_sel = 0,
>         .flags = LS2K2000_THSENS_OUT_FLAG,
> +       .thermal_ops = &loongson2_2k2000_of_thermal_ops,
>  };
>
>  static const struct of_device_id of_loongson2_thermal_match[] = {
> +       {
> +               .compatible = "loongson,ls2k0300-thermal",
> +               .data = &loongson2_thermal_ls2k0300_data,
> +       },
>         {
>                 .compatible = "loongson,ls2k1000-thermal",
>                 .data = &loongson2_thermal_ls2k1000_data,
> --
> 2.52.0
>