[PATCH 0/3] platform: arm64: qcom-hamoa-ec: Add thermistor support

[PATCH 0/3] platform: arm64: qcom-hamoa-ec: Add thermistor support

[Anvesh Jain P]

The Qualcomm Hamoa/Glymur embedded controller hosts multiple onboard
thermistors. This series registers the available thermistors with the
thermal framework and exposes them as thermal sensors, with the EC described
as a thermal-sensor provider for Glymur SoCs.

The series also adds the EC thermal-sensor references and corresponding back
cover, keyboard and SoC thermal zones to the Glymur CRD.

---
Anvesh Jain P (3):
      dt-bindings: embedded-controller: qcom,hamoa-crd-ec: Add thermal sensors
      platform: arm64: qcom-hamoa-ec: Add thermistor sensors
      arm64: dts: qcom: glymur: Add EC thermal zones

 .../embedded-controller/qcom,hamoa-crd-ec.yaml     | 12 ++++
 arch/arm64/boot/dts/qcom/glymur-crd.dtsi           | 45 ++++++++++++-
 drivers/platform/arm64/qcom-hamoa-ec.c             | 74 ++++++++++++++++++++++
 3 files changed, 130 insertions(+), 1 deletion(-)
---
base-commit: 93f51579e7df248780214094418f205253383cc5
change-id: 20260911-ec_thermistor_support-5122956d4831

Best regards,
--  
Anvesh Jain P <anvesh.p@oss.qualcomm.com>

[PATCH 1/3] dt-bindings: embedded-controller: qcom,hamoa-crd-ec: Add thermal sensors

[Anvesh Jain P]

Describe the Hamoa embedded controller as a thermal-sensor provider for
firmware-reported thermistors. The populated channels are discovered from
the EC firmware capability response.

Signed-off-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
---
 .../bindings/embedded-controller/qcom,hamoa-crd-ec.yaml      | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Documentation/devicetree/bindings/embedded-controller/qcom,hamoa-crd-ec.yaml b/Documentation/devicetree/bindings/embedded-controller/qcom,hamoa-crd-ec.yaml
index ac5a08f8f76d..13de6bed8129 100644
--- a/Documentation/devicetree/bindings/embedded-controller/qcom,hamoa-crd-ec.yaml
+++ b/Documentation/devicetree/bindings/embedded-controller/qcom,hamoa-crd-ec.yaml
@@ -15,6 +15,9 @@ description:
   EC running on different MCU chips. The EC handles things like fan control,
   temperature sensors, access to EC internal state changes.
 
+allOf:
+  - $ref: /schemas/thermal/thermal-sensor.yaml#
+
 properties:
   compatible:
     oneOf:
@@ -32,6 +35,14 @@ properties:
   interrupts:
     maxItems: 1
 
+  "#thermal-sensor-cells":
+    description:
+      The EC exposes up to 7 onboard thermistors (indices 0-6). Which
+      indices are physically populated on a given board is discovered at
+      runtime from EC firmware capabilities; a board may reference any index
+      0-6.
+    const: 1
+
 required:
   - compatible
   - reg
@@ -49,6 +60,7 @@ examples:
         embedded-controller@76 {
             compatible = "qcom,hamoa-crd-ec";
             reg = <0x76>;
+            #thermal-sensor-cells = <1>;
 
             interrupts-extended = <&tlmm 66 IRQ_TYPE_LEVEL_HIGH>;
         };

-- 
2.34.1

[PATCH 2/3] platform: arm64: qcom-hamoa-ec: Add thermistor sensors

[Anvesh Jain P]

The Qualcomm embedded controller has exclusive access to multiple onboard
thermistors programmatically discoverable through the
EC_THERMAL_CAPABILITIES command. The temperature values are reported in
degree Celsius through the EC_THERMISTOR_TEMP_CMD.

Register these thermistors with the thermal framework by adding support to
the EC_THERMISTOR_TEMP_CMD and convert it to millidegree units as required
by the thermal framework.

Signed-off-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
---
 drivers/platform/arm64/qcom-hamoa-ec.c | 74 ++++++++++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

diff --git a/drivers/platform/arm64/qcom-hamoa-ec.c b/drivers/platform/arm64/qcom-hamoa-ec.c
index 4d2ad042a7f8..acf3d7f53026 100644
--- a/drivers/platform/arm64/qcom-hamoa-ec.c
+++ b/drivers/platform/arm64/qcom-hamoa-ec.c
@@ -16,16 +16,19 @@
 #include <linux/pm.h>
 #include <linux/slab.h>
 #include <linux/thermal.h>
+#include <linux/unaligned.h>
 
 #define EC_SCI_EVT_READ_CMD	0x05
 #define EC_FW_VERSION_CMD	0x0e
 #define EC_MODERN_STANDBY_CMD	0x23
+#define EC_THERMISTOR_TEMP_CMD	0x29	/* + thermistor_id (0-6) selects thermistor 1-7 */
 #define EC_FAN_DBG_CONTROL_CMD	0x30
 #define EC_SCI_EVT_CONTROL_CMD	0x35
 #define EC_THERMAL_CAP_CMD	0x42
 
 #define EC_FW_VERSION_RESP_LEN	4
 #define EC_THERMAL_CAP_RESP_LEN	3
+#define EC_THERMISTOR_TEMP_RESP_LEN	3
 #define EC_FAN_DEBUG_CMD_LEN	6
 #define EC_FAN_SPEED_DATA_SIZE	4
 
@@ -39,6 +42,7 @@
 #define EC_MAX_FAN_CNT		2
 #define EC_FAN_NAME_SIZE	20
 #define EC_FAN_MAX_PWM		255
+#define EC_MAX_THERMISTOR_CNT	7
 
 enum qcom_ec_sci_events {
 	EC_FAN1_STATUS_CHANGE_EVT = 0x30,
@@ -64,6 +68,7 @@ struct qcom_ec_thermal_cap {
 #define EC_THERMAL_FAN_CNT(x)		(FIELD_GET(GENMASK(1, 0), (x)))
 #define EC_THERMAL_FAN_TYPE(x)		(FIELD_GET(GENMASK(4, 2), (x)))
 #define EC_THERMAL_THERMISTOR_MASK(x)	(FIELD_GET(GENMASK(7, 0), (x)))
+#define EC_THERMISTOR_PRESENT(mask, id)	((mask) & BIT(id))
 	u8 fan_cnt;
 	u8 fan_type;
 	u8 thermistor_mask;
@@ -81,6 +86,12 @@ struct qcom_ec {
 	struct qcom_ec_thermal_cap thermal_cap;
 	struct qcom_ec_version version;
 	struct i2c_client *client;
+	struct qcom_ec_thermal_zone *ec_tz;
+};
+
+struct qcom_ec_thermal_zone {
+	struct qcom_ec *ec;
+	u8 thermistor_id;
 };
 
 static int qcom_ec_read(struct qcom_ec *ec, u8 cmd, u8 resp_len, u8 *resp)
@@ -183,6 +194,43 @@ static int qcom_ec_thermal_capabilities(struct device *dev)
 	return 0;
 }
 
+/*
+ * EC Thermistor Temperature (cmd 0x29 + thermistor_id, id 0-6 selects
+ * thermistor 1-7):
+ *
+ * Read Response:
+ * ----------------------------------------------------------------------
+ * | Offset	| Name		| Description				|
+ * ----------------------------------------------------------------------
+ * | 0x00	| Byte count	| Number of bytes in response (=2)	|
+ * ----------------------------------------------------------------------
+ * | 0x01 (LSB)| Temperature	| Signed 16-bit, unit of 0.1 degC,	|
+ * | 0x02 (MSB)|		| range -40..+125 degC			|
+ * ----------------------------------------------------------------------
+ */
+static int qcom_ec_thermistor_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	struct qcom_ec_thermal_zone *ec_tz = thermal_zone_device_priv(tz);
+	struct qcom_ec *ec = ec_tz->ec;
+	u8 resp[EC_THERMISTOR_TEMP_RESP_LEN];
+	s16 raw;
+	int ret;
+
+	ret = qcom_ec_read(ec, EC_THERMISTOR_TEMP_CMD + ec_tz->thermistor_id,
+			   EC_THERMISTOR_TEMP_RESP_LEN, resp);
+	if (ret < 0)
+		return ret;
+
+	raw = (s16)get_unaligned_le16(&resp[1]);
+	*temp = raw * 100;
+
+	return 0;
+}
+
+static const struct thermal_zone_device_ops qcom_ec_thermistor_ops = {
+	.get_temp = qcom_ec_thermistor_get_temp,
+};
+
 static irqreturn_t qcom_ec_irq(int irq, void *data)
 {
 	struct qcom_ec *ec = data;
@@ -376,6 +424,32 @@ static int qcom_ec_probe(struct i2c_client *client)
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "Failed to read thermal capabilities\n");
 
+	if (ec->thermal_cap.thermistor_mask) {
+		ec->ec_tz = devm_kcalloc(dev, EC_MAX_THERMISTOR_CNT, sizeof(*ec->ec_tz),
+					 GFP_KERNEL);
+		if (!ec->ec_tz)
+			return -ENOMEM;
+
+		for (i = 0; i < EC_MAX_THERMISTOR_CNT; i++) {
+			struct qcom_ec_thermal_zone *ec_tz = &ec->ec_tz[i];
+			struct thermal_zone_device *tzd;
+
+			if (!EC_THERMISTOR_PRESENT(ec->thermal_cap.thermistor_mask, i))
+				continue;
+
+			ec_tz->ec = ec;
+			ec_tz->thermistor_id = i;
+
+			tzd = devm_thermal_of_zone_register(dev, i, ec_tz, &qcom_ec_thermistor_ops);
+			if (IS_ERR(tzd)) {
+				ret = PTR_ERR(tzd);
+				if (ret != -ENODEV)
+					dev_warn(dev, "Failed to register thermistor%u zone: %d\n",
+						 i, ret);
+			}
+		}
+	}
+
 	if (ec->thermal_cap.fan_cnt == 0) {
 		dev_warn(dev, FW_BUG "Failed to get fan count, firmware update required\n");
 		return 0;

-- 
2.34.1

[PATCH 3/3] arm64: dts: qcom: glymur: Add EC thermal zones

[Anvesh Jain P]

Add support for back cover, keyboard, and SoC thermal zones through
temperature sensors hosted on the EC for Glymur and Mahua CRDs.

Signed-off-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/glymur-crd.dtsi | 45 +++++++++++++++++++++++++++++++-
 1 file changed, 44 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/glymur-crd.dtsi b/arch/arm64/boot/dts/qcom/glymur-crd.dtsi
index e27c697e3170..571c98124a40 100644
--- a/arch/arm64/boot/dts/qcom/glymur-crd.dtsi
+++ b/arch/arm64/boot/dts/qcom/glymur-crd.dtsi
@@ -594,10 +594,12 @@ &i2c9 {
 
 	status = "okay";
 
-	embedded-controller@76 {
+	ec: embedded-controller@76 {
 		compatible = "qcom,glymur-crd-ec", "qcom,hamoa-crd-ec";
 		reg = <0x76>;
 
+		#thermal-sensor-cells = <1>;
+
 		interrupts-extended = <&tlmm 66 IRQ_TYPE_EDGE_FALLING>;
 
 		pinctrl-0 = <&ec_int_n_default>;
@@ -955,6 +957,47 @@ right_tweeter: speaker@0,1 {
 	};
 };
 
+&thermal_zones {
+	ec-back-cover {
+		polling-delay = <10000>;
+		thermal-sensors = <&ec 2>;
+
+		trips {
+			trip-point0 {
+				temperature = <90000>;
+				hysteresis = <5000>;
+				type = "hot";
+			};
+		};
+	};
+
+	ec-keyboard {
+		polling-delay = <10000>;
+		thermal-sensors = <&ec 1>;
+
+		trips {
+			trip-point0 {
+				temperature = <90000>;
+				hysteresis = <5000>;
+				type = "hot";
+			};
+		};
+	};
+
+	ec-soc {
+		polling-delay = <10000>;
+		thermal-sensors = <&ec 0>;
+
+		trips {
+			trip-point0 {
+				temperature = <90000>;
+				hysteresis = <5000>;
+				type = "hot";
+			};
+		};
+	};
+};
+
 &remoteproc_soccp {
 	firmware-name = "qcom/glymur/soccp.mbn",
 			"qcom/glymur/soccp_dtb.mbn";

-- 
2.34.1

Re: [PATCH 2/3] platform: arm64: qcom-hamoa-ec: Add thermistor sensors

[Ilpo Järvinen]

On Mon, 28 Sep 2026, Anvesh Jain P wrote:

> The Qualcomm embedded controller has exclusive access to multiple onboard
> thermistors programmatically discoverable through the
> EC_THERMAL_CAPABILITIES command. The temperature values are reported in
> degree Celsius through the EC_THERMISTOR_TEMP_CMD.
> 
> Register these thermistors with the thermal framework by adding support to
> the EC_THERMISTOR_TEMP_CMD and convert it to millidegree units as required
> by the thermal framework.
> 
> Signed-off-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
> ---
>  drivers/platform/arm64/qcom-hamoa-ec.c | 74 ++++++++++++++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
> 
> diff --git a/drivers/platform/arm64/qcom-hamoa-ec.c b/drivers/platform/arm64/qcom-hamoa-ec.c
> index 4d2ad042a7f8..acf3d7f53026 100644
> --- a/drivers/platform/arm64/qcom-hamoa-ec.c
> +++ b/drivers/platform/arm64/qcom-hamoa-ec.c
> @@ -16,16 +16,19 @@
>  #include <linux/pm.h>
>  #include <linux/slab.h>
>  #include <linux/thermal.h>
> +#include <linux/unaligned.h>
>  
>  #define EC_SCI_EVT_READ_CMD	0x05
>  #define EC_FW_VERSION_CMD	0x0e
>  #define EC_MODERN_STANDBY_CMD	0x23
> +#define EC_THERMISTOR_TEMP_CMD	0x29	/* + thermistor_id (0-6) selects thermistor 1-7 */
>  #define EC_FAN_DBG_CONTROL_CMD	0x30
>  #define EC_SCI_EVT_CONTROL_CMD	0x35
>  #define EC_THERMAL_CAP_CMD	0x42
>  
>  #define EC_FW_VERSION_RESP_LEN	4
>  #define EC_THERMAL_CAP_RESP_LEN	3
> +#define EC_THERMISTOR_TEMP_RESP_LEN	3
>  #define EC_FAN_DEBUG_CMD_LEN	6
>  #define EC_FAN_SPEED_DATA_SIZE	4
>  
> @@ -39,6 +42,7 @@
>  #define EC_MAX_FAN_CNT		2
>  #define EC_FAN_NAME_SIZE	20
>  #define EC_FAN_MAX_PWM		255
> +#define EC_MAX_THERMISTOR_CNT	7
>  
>  enum qcom_ec_sci_events {
>  	EC_FAN1_STATUS_CHANGE_EVT = 0x30,
> @@ -64,6 +68,7 @@ struct qcom_ec_thermal_cap {
>  #define EC_THERMAL_FAN_CNT(x)		(FIELD_GET(GENMASK(1, 0), (x)))
>  #define EC_THERMAL_FAN_TYPE(x)		(FIELD_GET(GENMASK(4, 2), (x)))
>  #define EC_THERMAL_THERMISTOR_MASK(x)	(FIELD_GET(GENMASK(7, 0), (x)))
> +#define EC_THERMISTOR_PRESENT(mask, id)	((mask) & BIT(id))
>  	u8 fan_cnt;
>  	u8 fan_type;
>  	u8 thermistor_mask;
> @@ -81,6 +86,12 @@ struct qcom_ec {
>  	struct qcom_ec_thermal_cap thermal_cap;
>  	struct qcom_ec_version version;
>  	struct i2c_client *client;
> +	struct qcom_ec_thermal_zone *ec_tz;
> +};
> +
> +struct qcom_ec_thermal_zone {
> +	struct qcom_ec *ec;
> +	u8 thermistor_id;
>  };
>  
>  static int qcom_ec_read(struct qcom_ec *ec, u8 cmd, u8 resp_len, u8 *resp)
> @@ -183,6 +194,43 @@ static int qcom_ec_thermal_capabilities(struct device *dev)
>  	return 0;
>  }
>  
> +/*
> + * EC Thermistor Temperature (cmd 0x29 + thermistor_id, id 0-6 selects
> + * thermistor 1-7):
> + *
> + * Read Response:
> + * ----------------------------------------------------------------------
> + * | Offset	| Name		| Description				|
> + * ----------------------------------------------------------------------
> + * | 0x00	| Byte count	| Number of bytes in response (=2)	|
> + * ----------------------------------------------------------------------
> + * | 0x01 (LSB)| Temperature	| Signed 16-bit, unit of 0.1 degC,	|
> + * | 0x02 (MSB)|		| range -40..+125 degC			|
> + * ----------------------------------------------------------------------
> + */
> +static int qcom_ec_thermistor_get_temp(struct thermal_zone_device *tz, int *temp)
> +{
> +	struct qcom_ec_thermal_zone *ec_tz = thermal_zone_device_priv(tz);
> +	struct qcom_ec *ec = ec_tz->ec;
> +	u8 resp[EC_THERMISTOR_TEMP_RESP_LEN];
> +	s16 raw;
> +	int ret;
> +
> +	ret = qcom_ec_read(ec, EC_THERMISTOR_TEMP_CMD + ec_tz->thermistor_id,
> +			   EC_THERMISTOR_TEMP_RESP_LEN, resp);
> +	if (ret < 0)
> +		return ret;
> +
> +	raw = (s16)get_unaligned_le16(&resp[1]);
> +	*temp = raw * 100;

MILLIDEGREE_PER_DECIDEGREE?

Make sure you have the include for it if changing to it.

> +
> +	return 0;
> +}
> +
> +static const struct thermal_zone_device_ops qcom_ec_thermistor_ops = {
> +	.get_temp = qcom_ec_thermistor_get_temp,
> +};
> +
>  static irqreturn_t qcom_ec_irq(int irq, void *data)
>  {
>  	struct qcom_ec *ec = data;
> @@ -376,6 +424,32 @@ static int qcom_ec_probe(struct i2c_client *client)
>  	if (ret < 0)
>  		return dev_err_probe(dev, ret, "Failed to read thermal capabilities\n");
>  
> +	if (ec->thermal_cap.thermistor_mask) {
> +		ec->ec_tz = devm_kcalloc(dev, EC_MAX_THERMISTOR_CNT, sizeof(*ec->ec_tz),
> +					 GFP_KERNEL);
> +		if (!ec->ec_tz)
> +			return -ENOMEM;
> +
> +		for (i = 0; i < EC_MAX_THERMISTOR_CNT; i++) {
> +			struct qcom_ec_thermal_zone *ec_tz = &ec->ec_tz[i];
> +			struct thermal_zone_device *tzd;
> +
> +			if (!EC_THERMISTOR_PRESENT(ec->thermal_cap.thermistor_mask, i))
> +				continue;
> +
> +			ec_tz->ec = ec;
> +			ec_tz->thermistor_id = i;
> +
> +			tzd = devm_thermal_of_zone_register(dev, i, ec_tz, &qcom_ec_thermistor_ops);
> +			if (IS_ERR(tzd)) {
> +				ret = PTR_ERR(tzd);
> +				if (ret != -ENODEV)

I'd prefer ret == -ENODEV check + continue.

> +					dev_warn(dev, "Failed to register thermistor%u zone: %d\n",
> +						 i, ret);
> +			}
> +		}
> +	}
> +
>  	if (ec->thermal_cap.fan_cnt == 0) {
>  		dev_warn(dev, FW_BUG "Failed to get fan count, firmware update required\n");
>  		return 0;
> 
> 

-- 
 i.

Re: [PATCH 3/3] arm64: dts: qcom: glymur: Add EC thermal zones

[Krzysztof Kozlowski]

On Mon, Sep 28, 2026 at 12:06:39PM +0530, Anvesh Jain P wrote:
> Add support for back cover, keyboard, and SoC thermal zones through
> temperature sensors hosted on the EC for Glymur and Mahua CRDs.
> 
> Signed-off-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
> ---
>  arch/arm64/boot/dts/qcom/glymur-crd.dtsi | 45 +++++++++++++++++++++++++++++++-
>  1 file changed, 44 insertions(+), 1 deletion(-)
>

It does not look like you tested the DTS against bindings. Please run
'make dtbs_check W=1' (see
Documentation/devicetree/bindings/writing-schema.rst or
https://www.linaro.org/blog/tips-and-tricks-for-validating-devicetree-sources-with-the-devicetree-schema/
for instructions).
Maybe you need to update your dtschema and yamllint. Don't rely on
distro packages for dtschema and be sure you are using the latest
released dtschema.

Best regards,
Krzysztof

Re: [PATCH 3/3] arm64: dts: qcom: glymur: Add EC thermal zones

[Anvesh Jain P]

On 9/29/2026 2:26 PM, Krzysztof Kozlowski wrote:
> On Mon, Sep 28, 2026 at 12:06:39PM +0530, Anvesh Jain P wrote:
>> Add support for back cover, keyboard, and SoC thermal zones through
>> temperature sensors hosted on the EC for Glymur and Mahua CRDs.
>>
>> Signed-off-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
>> ---
>>  arch/arm64/boot/dts/qcom/glymur-crd.dtsi | 45 +++++++++++++++++++++++++++++++-
>>  1 file changed, 44 insertions(+), 1 deletion(-)
>>
> 
> It does not look like you tested the DTS against bindings. Please run
> 'make dtbs_check W=1' (see
> Documentation/devicetree/bindings/writing-schema.rst or
> https://www.linaro.org/blog/tips-and-tricks-for-validating-devicetree-sources-with-the-devicetree-schema/
> for instructions).
> Maybe you need to update your dtschema and yamllint. Don't rely on
> distro packages for dtschema and be sure you are using the latest
> released dtschema.
> 
> Best regards,
> Krzysztof

Thanks for the review. I will update the thermal-zone node names to
comply with the schema and make sure to run the DTB validation with
updated dtschema.

-- 
Best Regards,
Anvesh

Re: [PATCH 2/3] platform: arm64: qcom-hamoa-ec: Add thermistor sensors

[Anvesh Jain P]

On 9/29/2026 1:05 PM, Ilpo Järvinen wrote:
> On Mon, 28 Sep 2026, Anvesh Jain P wrote:
> 
>> The Qualcomm embedded controller has exclusive access to multiple onboard
>> thermistors programmatically discoverable through the
>> EC_THERMAL_CAPABILITIES command. The temperature values are reported in
>> degree Celsius through the EC_THERMISTOR_TEMP_CMD.
>>
>> Register these thermistors with the thermal framework by adding support to
>> the EC_THERMISTOR_TEMP_CMD and convert it to millidegree units as required
>> by the thermal framework.
>>
>> Signed-off-by: Anvesh Jain P <anvesh.p@oss.qualcomm.com>
>> ---
>>  drivers/platform/arm64/qcom-hamoa-ec.c | 74 ++++++++++++++++++++++++++++++++++
>>  1 file changed, 74 insertions(+)
>>
>> diff --git a/drivers/platform/arm64/qcom-hamoa-ec.c b/drivers/platform/arm64/qcom-hamoa-ec.c
>> index 4d2ad042a7f8..acf3d7f53026 100644
>> --- a/drivers/platform/arm64/qcom-hamoa-ec.c
>> +++ b/drivers/platform/arm64/qcom-hamoa-ec.c
>> @@ -16,16 +16,19 @@
>>  #include <linux/pm.h>
>>  #include <linux/slab.h>
>>  #include <linux/thermal.h>
>> +#include <linux/unaligned.h>
>>  
>>  #define EC_SCI_EVT_READ_CMD	0x05
>>  #define EC_FW_VERSION_CMD	0x0e
>>  #define EC_MODERN_STANDBY_CMD	0x23
>> +#define EC_THERMISTOR_TEMP_CMD	0x29	/* + thermistor_id (0-6) selects thermistor 1-7 */
>>  #define EC_FAN_DBG_CONTROL_CMD	0x30
>>  #define EC_SCI_EVT_CONTROL_CMD	0x35
>>  #define EC_THERMAL_CAP_CMD	0x42
>>  
>>  #define EC_FW_VERSION_RESP_LEN	4
>>  #define EC_THERMAL_CAP_RESP_LEN	3
>> +#define EC_THERMISTOR_TEMP_RESP_LEN	3
>>  #define EC_FAN_DEBUG_CMD_LEN	6
>>  #define EC_FAN_SPEED_DATA_SIZE	4
>>  
>> @@ -39,6 +42,7 @@
>>  #define EC_MAX_FAN_CNT		2
>>  #define EC_FAN_NAME_SIZE	20
>>  #define EC_FAN_MAX_PWM		255
>> +#define EC_MAX_THERMISTOR_CNT	7
>>  
>>  enum qcom_ec_sci_events {
>>  	EC_FAN1_STATUS_CHANGE_EVT = 0x30,
>> @@ -64,6 +68,7 @@ struct qcom_ec_thermal_cap {
>>  #define EC_THERMAL_FAN_CNT(x)		(FIELD_GET(GENMASK(1, 0), (x)))
>>  #define EC_THERMAL_FAN_TYPE(x)		(FIELD_GET(GENMASK(4, 2), (x)))
>>  #define EC_THERMAL_THERMISTOR_MASK(x)	(FIELD_GET(GENMASK(7, 0), (x)))
>> +#define EC_THERMISTOR_PRESENT(mask, id)	((mask) & BIT(id))
>>  	u8 fan_cnt;
>>  	u8 fan_type;
>>  	u8 thermistor_mask;
>> @@ -81,6 +86,12 @@ struct qcom_ec {
>>  	struct qcom_ec_thermal_cap thermal_cap;
>>  	struct qcom_ec_version version;
>>  	struct i2c_client *client;
>> +	struct qcom_ec_thermal_zone *ec_tz;
>> +};
>> +
>> +struct qcom_ec_thermal_zone {
>> +	struct qcom_ec *ec;
>> +	u8 thermistor_id;
>>  };
>>  
>>  static int qcom_ec_read(struct qcom_ec *ec, u8 cmd, u8 resp_len, u8 *resp)
>> @@ -183,6 +194,43 @@ static int qcom_ec_thermal_capabilities(struct device *dev)
>>  	return 0;
>>  }
>>  
>> +/*
>> + * EC Thermistor Temperature (cmd 0x29 + thermistor_id, id 0-6 selects
>> + * thermistor 1-7):
>> + *
>> + * Read Response:
>> + * ----------------------------------------------------------------------
>> + * | Offset	| Name		| Description				|
>> + * ----------------------------------------------------------------------
>> + * | 0x00	| Byte count	| Number of bytes in response (=2)	|
>> + * ----------------------------------------------------------------------
>> + * | 0x01 (LSB)| Temperature	| Signed 16-bit, unit of 0.1 degC,	|
>> + * | 0x02 (MSB)|		| range -40..+125 degC			|
>> + * ----------------------------------------------------------------------
>> + */
>> +static int qcom_ec_thermistor_get_temp(struct thermal_zone_device *tz, int *temp)
>> +{
>> +	struct qcom_ec_thermal_zone *ec_tz = thermal_zone_device_priv(tz);
>> +	struct qcom_ec *ec = ec_tz->ec;
>> +	u8 resp[EC_THERMISTOR_TEMP_RESP_LEN];
>> +	s16 raw;
>> +	int ret;
>> +
>> +	ret = qcom_ec_read(ec, EC_THERMISTOR_TEMP_CMD + ec_tz->thermistor_id,
>> +			   EC_THERMISTOR_TEMP_RESP_LEN, resp);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	raw = (s16)get_unaligned_le16(&resp[1]);
>> +	*temp = raw * 100;
> 
> MILLIDEGREE_PER_DECIDEGREE?
> 
> Make sure you have the include for it if changing to it.
> 
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct thermal_zone_device_ops qcom_ec_thermistor_ops = {
>> +	.get_temp = qcom_ec_thermistor_get_temp,
>> +};
>> +
>>  static irqreturn_t qcom_ec_irq(int irq, void *data)
>>  {
>>  	struct qcom_ec *ec = data;
>> @@ -376,6 +424,32 @@ static int qcom_ec_probe(struct i2c_client *client)
>>  	if (ret < 0)
>>  		return dev_err_probe(dev, ret, "Failed to read thermal capabilities\n");
>>  
>> +	if (ec->thermal_cap.thermistor_mask) {
>> +		ec->ec_tz = devm_kcalloc(dev, EC_MAX_THERMISTOR_CNT, sizeof(*ec->ec_tz),
>> +					 GFP_KERNEL);
>> +		if (!ec->ec_tz)
>> +			return -ENOMEM;
>> +
>> +		for (i = 0; i < EC_MAX_THERMISTOR_CNT; i++) {
>> +			struct qcom_ec_thermal_zone *ec_tz = &ec->ec_tz[i];
>> +			struct thermal_zone_device *tzd;
>> +
>> +			if (!EC_THERMISTOR_PRESENT(ec->thermal_cap.thermistor_mask, i))
>> +				continue;
>> +
>> +			ec_tz->ec = ec;
>> +			ec_tz->thermistor_id = i;
>> +
>> +			tzd = devm_thermal_of_zone_register(dev, i, ec_tz, &qcom_ec_thermistor_ops);
>> +			if (IS_ERR(tzd)) {
>> +				ret = PTR_ERR(tzd);
>> +				if (ret != -ENODEV)
> 
> I'd prefer ret == -ENODEV check + continue.
> 
>> +					dev_warn(dev, "Failed to register thermistor%u zone: %d\n",
>> +						 i, ret);
>> +			}
>> +		}
>> +	}
>> +
>>  	if (ec->thermal_cap.fan_cnt == 0) {
>>  		dev_warn(dev, FW_BUG "Failed to get fan count, firmware update required\n");
>>  		return 0;
>>
>>
>

Thanks for the review. I will use MILLIDEGREE_PER_DECIDEGREE from
<linux/units.h> for the temperature conversion. I will also change the
thermal-zone registration handling to continue explicitly on -ENODEV and
warn about other errors.

-- 
Best Regards,
Anvesh