[PATCH v2 0/3] Add INA232 power monitor support for Arduino VENTUNO Q

[PATCH v2 0/3] Add INA232 power monitor support for Arduino VENTUNO Q

[Loic Poulain]

Add support for the TI INA232 current/power monitor to the ina2xx
hwmon driver, and enable it on the Arduino Monza board.

The INA232 is a bidirectional current/power monitor that shares the
same I2C register layout as the INA226, but has different electrical
characteristics.

On the Arduino Monza/Ventuno-Q board, the INA232 is connected on
I2C12 at address 0x40 with a 2 mΩ shunt resistor, and is used to
monitor the board supply current.

Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
Changes in v2:
- has_update_interval was missing and should be set to true/supported
  (sashiko/Guenter)
- ti,ina232 added to two allOf conditional exclusion blocks. (sashiko)
- Fix commit message, it incorrectly mentioned 2Mohm instead of
  milli-ohm. (sahiko, Konrad).

- Link to v1: https://lore.kernel.org/r/20260610-monza-ina232-v1-0-925b0d12771b@oss.qualcomm.com

---
Loic Poulain (1):
      arm64: dts: qcom: monaco-arduino-monza: add ina232 power sensor

Martino Facchin (2):
      dt-bindings: hwmon: ina2xx: add ina232 compatible
      hwmon: ina2xx: support ina232

 .../devicetree/bindings/hwmon/ti,ina2xx.yaml         |  3 +++
 arch/arm64/boot/dts/qcom/monaco-arduino-monza.dts    |  6 ++++++
 drivers/hwmon/ina2xx.c                               | 20 ++++++++++++++++++++
 3 files changed, 29 insertions(+)
---
base-commit: 8a4062d204752e0d66a1e7e1a2f8834571a8d40f
change-id: 20260610-monza-ina232-de180e669dc1

Best regards,
-- 
Loic Poulain <loic.poulain@oss.qualcomm.com>

[PATCH v2 1/3] dt-bindings: hwmon: ina2xx: add ina232 compatible

[Loic Poulain]

From: Martino Facchin <m.facchin@arduino.cc>

The INA232 is a current/power monitor from Texas Instruments sharing
the same register map as the other INA2xx.

Signed-off-by: Martino Facchin <m.facchin@arduino.cc>
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml b/Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml
index 009d78b308596ca795bebdd160431bd718b127e0..a79ade3142fa4f36f2ae4655bbf0db8ad84ec13a 100644
--- a/Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml
+++ b/Documentation/devicetree/bindings/hwmon/ti,ina2xx.yaml
@@ -28,6 +28,7 @@ properties:
       - ti,ina228
       - ti,ina230
       - ti,ina231
+      - ti,ina232
       - ti,ina233
       - ti,ina234
       - ti,ina237
@@ -114,6 +115,7 @@ allOf:
               - ti,ina228
               - ti,ina230
               - ti,ina231
+              - ti,ina232
               - ti,ina234
               - ti,ina237
               - ti,ina238
@@ -136,6 +138,7 @@ allOf:
               - ti,ina226
               - ti,ina230
               - ti,ina231
+              - ti,ina232
               - ti,ina234
               - ti,ina260
               - ti,ina700

-- 
2.34.1

[PATCH v2 2/3] hwmon: ina2xx: support ina232

[Loic Poulain]

From: Martino Facchin <m.facchin@arduino.cc>

The INA232 is a current/power monitor. It shares the same register
layout as the INA2xx and uses the INA226 default configuration, but
differs in its electrical characteristics:

Signed-off-by: Martino Facchin <m.facchin@arduino.cc>
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 drivers/hwmon/ina2xx.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 613ffb622b7c42b8b6090d3b4ec7b2fa412e24a4..fc2319ad99fc398a50e97ee617f67255bd0b3038 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -122,6 +122,7 @@ static const struct regmap_config ina2xx_regmap_config = {
 enum ina2xx_ids {
 	ina219,
 	ina226,
+	ina232,
 	ina234,
 	ina260,
 	sy24655
@@ -196,6 +197,20 @@ static const struct ina2xx_config ina2xx_config[] = {
 		.current_shift = 4,
 		.has_update_interval = true,
 	},
+	[ina232] = {
+		.config_default = INA226_CONFIG_DEFAULT,
+		.calibration_value = 2048,
+		.shunt_div = 400,
+		.shunt_voltage_shift = 0,
+		.bus_voltage_shift = 0,
+		.bus_voltage_lsb = 1600,
+		.power_lsb_factor = 32,
+		.has_alerts = true,
+		.has_ishunt = false,
+		.has_power_average = false,
+		.current_shift = 0,
+		.has_update_interval = true,
+	},
 	[ina260] = {
 		.config_default = INA260_CONFIG_DEFAULT,
 		.shunt_div = 400,
@@ -1005,6 +1020,7 @@ static const struct i2c_device_id ina2xx_id[] = {
 	{ "ina226", ina226 },
 	{ "ina230", ina226 },
 	{ "ina231", ina226 },
+	{ "ina232", ina232 },
 	{ "ina234", ina234 },
 	{ "ina260", ina260 },
 	{ "sy24655", sy24655 },
@@ -1037,6 +1053,10 @@ static const struct of_device_id __maybe_unused ina2xx_of_match[] = {
 		.compatible = "ti,ina231",
 		.data = (void *)ina226
 	},
+	{
+		.compatible = "ti,ina232",
+		.data = (void *)ina232
+	},
 	{
 		.compatible = "ti,ina234",
 		.data = (void *)ina234

-- 
2.34.1

[PATCH v2 3/3] arm64: dts: qcom: monaco-arduino-monza: add ina232 power sensor

[Loic Poulain]

The Arduino Monza board has a TI INA232 current/power monitor connected
on I2C12 at address 0x40. It is used to measure the board supply current
through a 2 milliohms shunt resistor.

Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 arch/arm64/boot/dts/qcom/monaco-arduino-monza.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/monaco-arduino-monza.dts b/arch/arm64/boot/dts/qcom/monaco-arduino-monza.dts
index 379b796f261f4c8f6b7712c5d340b20be1b9217c..a526c8a07b30c22820f54b54644916b268496209 100644
--- a/arch/arm64/boot/dts/qcom/monaco-arduino-monza.dts
+++ b/arch/arm64/boot/dts/qcom/monaco-arduino-monza.dts
@@ -291,6 +291,12 @@ adv7535_out: endpoint {
 			};
 		};
 	};
+
+	power-sensor@40 {
+		compatible = "ti,ina232";
+		reg = <0x40>;
+		shunt-resistor = <2000>;
+	};
 };
 
 &mdss {

-- 
2.34.1

Re: [PATCH v2 3/3] arm64: dts: qcom: monaco-arduino-monza: add ina232 power sensor

[sashiko-bot]

> The Arduino Monza board has a TI INA232 current/power monitor connected
> on I2C12 at address 0x40. It is used to measure the board supply current
> through a 2 milliohms shunt resistor.
> 
> Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260611-monza-ina232-v2-0-e4375ce652d0@oss.qualcomm.com?part=3

Re: [PATCH v2 1/3] dt-bindings: hwmon: ina2xx: add ina232 compatible

[sashiko-bot]

> From: Martino Facchin <m.facchin@arduino.cc>
> 
> The INA232 is a current/power monitor from Texas Instruments sharing
> the same register map as the other INA2xx.
> 
> Signed-off-by: Martino Facchin <m.facchin@arduino.cc>
> Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260611-monza-ina232-v2-0-e4375ce652d0@oss.qualcomm.com?part=1

Re: [PATCH v2 2/3] hwmon: ina2xx: support ina232

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:

Pre-existing issues:
- [High] Power alert limit calculation always evaluates to 0 on 32-bit systems due to `UINT_MAX` underflow when cast to a signed long.
- [High] Setting a high bus voltage alert limit on 32-bit systems causes signed integer overflow for chips with a high `bus_voltage_shift`.
- [High] Arithmetic overflow and truncation in power and current reading calculations due to 32-bit signed integer limits.
--

commit 1860bedc8e47e2aefaa388ad7ade74649ff17da9
Author: Martino Facchin <m.facchin@arduino.cc>

hwmon: ina2xx: support ina232

The INA232 is a current/power monitor. It shares the same register
layout as the INA2xx and uses the INA226 default configuration, but
differs in its electrical characteristics.

> diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
> index 613ffb622b7c4..fc2319ad99fc3 100644
> --- a/drivers/hwmon/ina2xx.c
> +++ b/drivers/hwmon/ina2xx.c
> @@ -196,6 +197,20 @@ static const struct ina2xx_config ina2xx_config[] = {
>  		.current_shift = 4,
>  		.has_update_interval = true,
>  	},
> +	[ina232] = {
> +		.config_default = INA226_CONFIG_DEFAULT,
> +		.calibration_value = 2048,
> +		.shunt_div = 400,
> +		.shunt_voltage_shift = 0,
> +		.bus_voltage_shift = 0,
> +		.bus_voltage_lsb = 1600,
> +		.power_lsb_factor = 32,
> +		.has_alerts = true,
> +		.has_ishunt = false,
> +		.has_power_average = false,
> +		.current_shift = 0,
> +		.has_update_interval = true,
> +	},

[Severity: High]
This is a pre-existing issue, but does power alert configuration work correctly
on 32-bit systems?

In ina226_alert_to_reg() for INA2XX_POWER, the limit is clamped using:

        val = clamp_val(val, 0, UINT_MAX - data->power_lsb_uW);
        val = DIV_ROUND_CLOSEST(val, data->power_lsb_uW);
        return clamp_val(val, 0, USHRT_MAX);

The clamp_val() macro casts its limit arguments to the type of val, which is
a signed long. On 32-bit systems, UINT_MAX - data->power_lsb_uW evaluates to
a negative value.

Because the maximum limit is negative, clamp_val() forces any positive input
to this negative limit, and the final clamp_val(..., 0, USHRT_MAX) will
unconditionally return 0, silently disabling or instantly triggering alerts.

[Severity: High]
This isn't a bug introduced by this patch, but could setting high bus voltage
alerts on 32-bit systems cause an integer overflow?

In ina226_alert_to_reg() for INA2XX_BUS_VOLTAGE, the value is calculated as:

        val = clamp_val(val, 0, 200000);
        val = (val * 1000) << data->config->bus_voltage_shift;

For chips with a high bus_voltage_shift like the INA234 (shift = 4), a valid
high input limit such as 150,000 mV evaluates to (150,000 * 1000) << 4,
which equals 2,400,000,000.

On 32-bit architectures, this exceeds the maximum positive value for a
signed long, overflowing into a negative number. The subsequent clamp to
USHRT_MAX then limits this to 0, converting legitimate high voltage limits
to 0.

[Severity: High]
This is a pre-existing issue, but does this calculation overflow for systems
measuring high loads with low-value shunt resistors?

In ina2xx_get_value(), the calculation is stored in a 32-bit signed integer:

static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
                            unsigned int regval)
{
        int val;
        ...
        case INA2XX_POWER:
                val = regval * data->power_lsb_uW;
                break;

For a system using a 1 mOhm shunt, power_lsb_uW might be 80,000. If regval
is large (e.g., 65535), the product exceeds INT_MAX.

This overflows on 32-bit systems or truncates when assigned to the 32-bit
integer val on 64-bit systems, causing the driver to report completely
incorrect and often large negative values.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260611-monza-ina232-v2-0-e4375ce652d0@oss.qualcomm.com?part=2