[PATCH 0/2] Add support for MAX20830 PMBUS

[PATCH 0/2] Add support for MAX20830 PMBUS

[Alexis Czezar Torreno]

This series adds support for the Analog Devices MAX20830 step-down
switching regulator with PMBus interface.

The MAX20830 provides 2.7V to 16V input, 0.4V to 5.8V output, and up
to 30A output current. It supports monitoring of input/output voltage,
output current, and temperature via PMBus.

Datasheet: https://www.analog.com/en/products/max20830.html

Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
---
Alexis Czezar Torreno (2):
      dt-bindings: hwmon: pmbus: add max20830
      hwmon: (pmbus/max20830) add driver for max20830

 .../bindings/hwmon/pmbus/adi,max20830.yaml         | 58 +++++++++++++++++
 Documentation/hwmon/index.rst                      |  1 +
 Documentation/hwmon/max20830.rst                   | 48 ++++++++++++++
 MAINTAINERS                                        |  9 +++
 drivers/hwmon/pmbus/Kconfig                        |  9 +++
 drivers/hwmon/pmbus/Makefile                       |  1 +
 drivers/hwmon/pmbus/max20830.c                     | 74 ++++++++++++++++++++++
 7 files changed, 200 insertions(+)
---
base-commit: fb447217c59a13b2fff22d94de2498c185cd9032
change-id: 20260414-dev_max20830-9460b92cf6aa

Best regards,
-- 
Alexis Czezar Torreno <alexisczezar.torreno@analog.com>

[PATCH 1/2] dt-bindings: hwmon: pmbus: add max20830

[Alexis Czezar Torreno]

Add device tree documentation for MAX20830 step-down DC-DC switching
regulator with PMBus interface.

Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
---
 .../bindings/hwmon/pmbus/adi,max20830.yaml         | 58 ++++++++++++++++++++++
 MAINTAINERS                                        |  7 +++
 2 files changed, 65 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..b20f3be176615895e70e74bfb2a534d82d124a15
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/pmbus/adi,max20830.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices MAX20830 Step-Down Switching Regulator with PMBus
+
+maintainers:
+  - Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
+
+description: |
+  The MAX20830 is a fully integrated step-down DC-DC switching regulator with
+  PMBus interface. It provides 2.7V to 16V input, 0.4V to 5.8V adjustable
+  output, and up to 30A output current. It allows monitoring of input/output
+  voltage, output current and temperature through the PMBus serial interface.
+  Datasheet:
+    https://www.analog.com/en/products/max20830.html
+
+properties:
+  compatible:
+    const: adi,max20830
+
+  reg:
+    maxItems: 1
+
+  vddh-supply:
+    description:
+      Phandle to the regulator that provides the VDDH power supply.
+
+  avdd-supply:
+    description:
+      Phandle to the regulator that provides the AVDD power supply.
+
+  ldoin-supply:
+    description:
+      Optional 2.5V to 5.5V LDO input supply.
+
+required:
+  - compatible
+  - reg
+  - vddh-supply
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        hwmon@30 {
+            compatible = "adi,max20830";
+            reg = <0x30>;
+            vddh-supply = <&vddh>;
+        };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 0a3991c10ade20dd79cc7d1bf2a1d307ba6bd19d..031c743e979521a92ed9ac67915c178ce31727bd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15579,6 +15579,13 @@ F:	Documentation/devicetree/bindings/hwmon/pmbus/adi,max17616.yaml
 F:	Documentation/hwmon/max17616.rst
 F:	drivers/hwmon/pmbus/max17616.c
 
+MAX20830 HARDWARE MONITOR DRIVER
+M:	Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
+L:	linux-hwmon@vger.kernel.org
+S:	Supported
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml
+
 MAX2175 SDR TUNER DRIVER
 M:	Ramesh Shanmugasundaram <rashanmu@gmail.com>
 L:	linux-media@vger.kernel.org

-- 
2.34.1

Re: [PATCH 1/2] dt-bindings: hwmon: pmbus: add max20830

[sashiko-bot]

Sashiko AI review found 3 potential issue(s):
- [Medium] Incomplete Regulator Schema
- [Medium] Missing Hardware Capability (Interrupts)
- [Low] Devicetree Best Practices Violation (Node Name)
--

commit 20a4d8dcd2f3344ac22d7d2e974bae1ef57874ed
Author: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>

dt-bindings: hwmon: pmbus: add max20830

This commit adds device tree documentation for the MAX20830 step-down DC-DC
switching regulator with PMBus interface. It allows monitoring of voltage,
current, and temperature.

> diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml
> new file mode 100644
> index 0000000000000..b20f3be176615
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml
[ ... ]
> +properties:
> +  compatible:
> +    const: adi,max20830
> +
> +  reg:
> +    maxItems: 1
> +

Since this is a PMBus device that typically signals hardware faults to the
host via the standard SMBALERT# pin, should the schema define the optional
interrupts property?

> +  vddh-supply:
> +    description:
> +      Phandle to the regulator that provides the VDDH power supply.
[ ... ]
> +required:
> +  - compatible
> +  - reg
> +  - vddh-supply
> +
> +additionalProperties: false

The commit message explicitly states the MAX20830 is a step-down DC-DC
switching regulator with an adjustable output, but the schema omits any
reference to the core regulator schema or a regulators child node.

Because additionalProperties is set to false, does this prevent board
designers from describing the hardware's standard output constraints,
such as regulator-min-microvolt or regulator-max-microvolt, without
causing a schema validation error?

> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        hwmon@30 {

This isn't a bug, but the device node name in the example uses a Linux
subsystem name. Should it use a generic functional name representing the
hardware, such as regulator@30 or power-sensor@30?

> +            compatible = "adi,max20830";
> +            reg = <0x30>;
> +            vddh-supply = <&vddh>;
> +        };
> +    };
> +...

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260414-dev_max20830-v1-0-210d3f82c571@analog.com?part=1

Re: [PATCH 1/2] dt-bindings: hwmon: pmbus: add max20830

[Krzysztof Kozlowski]

On Tue, Apr 14, 2026 at 04:38:40AM +0000, sashiko-bot@kernel.org wrote:
> Sashiko AI review found 3 potential issue(s):
> - [Medium] Incomplete Regulator Schema
> - [Medium] Missing Hardware Capability (Interrupts)
> - [Low] Devicetree Best Practices Violation (Node Name)
> --
> 
> commit 20a4d8dcd2f3344ac22d7d2e974bae1ef57874ed
> Author: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
> 
> dt-bindings: hwmon: pmbus: add max20830
> 
> This commit adds device tree documentation for the MAX20830 step-down DC-DC
> switching regulator with PMBus interface. It allows monitoring of voltage,
> current, and temperature.

Sashiko devs,
Can we drop such comments? They are useless - we know what the commit is
doing, no point for reviewing tool to say it again.

Please send only useful feedback to mailing list, otherwise this will be
just noise and going to be ignored.

Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: hwmon: pmbus: add max20830

[Roman Gushchin]

Krzysztof Kozlowski <krzk@kernel.org> writes:

> On Tue, Apr 14, 2026 at 04:38:40AM +0000, sashiko-bot@kernel.org wrote:
>> Sashiko AI review found 3 potential issue(s):
>> - [Medium] Incomplete Regulator Schema
>> - [Medium] Missing Hardware Capability (Interrupts)
>> - [Low] Devicetree Best Practices Violation (Node Name)
>> --
>> 
>> commit 20a4d8dcd2f3344ac22d7d2e974bae1ef57874ed
>> Author: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
>> 
>> dt-bindings: hwmon: pmbus: add max20830
>> 
>> This commit adds device tree documentation for the MAX20830 step-down DC-DC
>> switching regulator with PMBus interface. It allows monitoring of voltage,
>> current, and temperature.
>
> Sashiko devs,
> Can we drop such comments? They are useless - we know what the commit is
> doing, no point for reviewing tool to say it again.

It's the format which originated from initial Chris Mason's prompts
and as *I understand* it's purpose was to make sure the llm is reviewing
the right patch and more or less understands it. Idk if we still need
this, but at least some find it useful: e.g.
https://github.com/sashiko-dev/sashiko/issues/90 .

I'm planning to do it configurable in UI, but for emails I can
only make it configurable on per-subsystem basis.
If there is a consensus amongst hwmon maintainers, I'm happy to remove
it for hwmon (in several days).

>
> Please send only useful feedback to mailing list, otherwise this will be
> just noise and going to be ignored.

Agree, but there are many sometimes conflicting opinions on what's
useful and what's not. So I'm trying to make it as flexible and
configurable as possible.

Thanks

Re: [PATCH 1/2] dt-bindings: hwmon: pmbus: add max20830

[Guenter Roeck]

On Thu, Apr 16, 2026 at 05:45:52PM +0000, Roman Gushchin wrote:
> Krzysztof Kozlowski <krzk@kernel.org> writes:
> 
> > On Tue, Apr 14, 2026 at 04:38:40AM +0000, sashiko-bot@kernel.org wrote:
> >> Sashiko AI review found 3 potential issue(s):
> >> - [Medium] Incomplete Regulator Schema
> >> - [Medium] Missing Hardware Capability (Interrupts)
> >> - [Low] Devicetree Best Practices Violation (Node Name)
> >> --
> >> 
> >> commit 20a4d8dcd2f3344ac22d7d2e974bae1ef57874ed
> >> Author: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
> >> 
> >> dt-bindings: hwmon: pmbus: add max20830
> >> 
> >> This commit adds device tree documentation for the MAX20830 step-down DC-DC
> >> switching regulator with PMBus interface. It allows monitoring of voltage,
> >> current, and temperature.
> >
> > Sashiko devs,
> > Can we drop such comments? They are useless - we know what the commit is
> > doing, no point for reviewing tool to say it again.
> 
> It's the format which originated from initial Chris Mason's prompts
> and as *I understand* it's purpose was to make sure the llm is reviewing
> the right patch and more or less understands it. Idk if we still need
> this, but at least some find it useful: e.g.
> https://github.com/sashiko-dev/sashiko/issues/90 .
> 
> I'm planning to do it configurable in UI, but for emails I can
> only make it configurable on per-subsystem basis.
> If there is a consensus amongst hwmon maintainers, I'm happy to remove
> it for hwmon (in several days).

I find it useful. Please don't take it out. Maybe there is a means to drop
it from devicetree patches if that is what devicetree maintainers want. Fine
with me to drop it for those, or to drop devicetree feedback entirely if
that is what devicetree maintainers want and if it is possible to separate
devicetree patches submitted as part of a hwmon series from the actual code
patches.

Thanks,
Guenter

> 
> >
> > Please send only useful feedback to mailing list, otherwise this will be
> > just noise and going to be ignored.
> 
> Agree, but there are many sometimes conflicting opinions on what's
> useful and what's not. So I'm trying to make it as flexible and
> configurable as possible.
> 
> Thanks
> 

Re: [PATCH 1/2] dt-bindings: hwmon: pmbus: add max20830

[Krzysztof Kozlowski]

On 16/04/2026 20:09, Guenter Roeck wrote:
> On Thu, Apr 16, 2026 at 05:45:52PM +0000, Roman Gushchin wrote:
>> Krzysztof Kozlowski <krzk@kernel.org> writes:
>>
>>> On Tue, Apr 14, 2026 at 04:38:40AM +0000, sashiko-bot@kernel.org wrote:
>>>> Sashiko AI review found 3 potential issue(s):
>>>> - [Medium] Incomplete Regulator Schema
>>>> - [Medium] Missing Hardware Capability (Interrupts)
>>>> - [Low] Devicetree Best Practices Violation (Node Name)
>>>> --
>>>>
>>>> commit 20a4d8dcd2f3344ac22d7d2e974bae1ef57874ed
>>>> Author: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
>>>>
>>>> dt-bindings: hwmon: pmbus: add max20830
>>>>
>>>> This commit adds device tree documentation for the MAX20830 step-down DC-DC
>>>> switching regulator with PMBus interface. It allows monitoring of voltage,
>>>> current, and temperature.
>>>
>>> Sashiko devs,
>>> Can we drop such comments? They are useless - we know what the commit is
>>> doing, no point for reviewing tool to say it again.
>>
>> It's the format which originated from initial Chris Mason's prompts
>> and as *I understand* it's purpose was to make sure the llm is reviewing
>> the right patch and more or less understands it. Idk if we still need
>> this, but at least some find it useful: e.g.
>> https://github.com/sashiko-dev/sashiko/issues/90 .
>>
>> I'm planning to do it configurable in UI, but for emails I can
>> only make it configurable on per-subsystem basis.
>> If there is a consensus amongst hwmon maintainers, I'm happy to remove
>> it for hwmon (in several days).
> 
> I find it useful. Please don't take it out. Maybe there is a means to drop
> it from devicetree patches if that is what devicetree maintainers want. Fine
> with me to drop it for those, or to drop devicetree feedback entirely if
> that is what devicetree maintainers want and if it is possible to separate
> devicetree patches submitted as part of a hwmon series from the actual code
> patches.
> 

If there are folks who want them, then it's fine, don't make exception
just for me. I can skip first paragraphs by default :)

Best regards,
Krzysztof

[PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

[Alexis Czezar Torreno]

Add support for MAX20830 step-down DC-DC switching regulator with
PMBus interface. It allows monitoring of input/output voltage,
output current and temperature through the PMBus serial interface.

Signed-off-by: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
---
 Documentation/hwmon/index.rst    |  1 +
 Documentation/hwmon/max20830.rst | 48 ++++++++++++++++++++++++++
 MAINTAINERS                      |  2 ++
 drivers/hwmon/pmbus/Kconfig      |  9 +++++
 drivers/hwmon/pmbus/Makefile     |  1 +
 drivers/hwmon/pmbus/max20830.c   | 74 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 135 insertions(+)

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 8b655e5d6b68b90c697a52c7bf526e81d370caf7..56f7eb761be76dd627a2f34135abad05203b0582 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -158,6 +158,7 @@ Hardware Monitoring Kernel Drivers
    max197
    max20730
    max20751
+   max20830
    max31722
    max31730
    max31760
diff --git a/Documentation/hwmon/max20830.rst b/Documentation/hwmon/max20830.rst
new file mode 100644
index 0000000000000000000000000000000000000000..b9dffb76059781932d383ed798cecff69e738873
--- /dev/null
+++ b/Documentation/hwmon/max20830.rst
@@ -0,0 +1,48 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver max20830
+======================
+
+Supported chips:
+
+  * Analog Devices MAX20830
+
+    Prefix: 'max20830'
+
+    Addresses scanned: -
+
+    Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/max20830.pdf
+
+Author:
+
+  - Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
+
+
+Description
+-----------
+
+This driver supports hardware monitoring for Analog Devices MAX20830
+Step-Down Switching Regulator with PMBus Interface.
+
+The MAX20830 is a 2.7V to 16V, 30A fully integrated step-down DC-DC switching
+regulator. Through the PMBus interface, the device can monitor input/output
+voltages, output current and temperature.
+
+The driver is a client driver to the core PMBus driver. Please see
+Documentation/hwmon/pmbus.rst for details on PMBus client drivers.
+
+Sysfs entries
+-------------
+
+================= ========================================
+in1_label         "vin"
+in1_input         Measured input voltage
+in1_alarm         Input voltage alarm
+in2_label         "vout1"
+in2_input         Measured output voltage
+curr1_label       "iout1"
+curr1_input       Measured output current
+curr1_alarm       Output current alarm
+temp1_input       Measured temperature
+temp1_alarm       Chip temperature alarm
+================= ========================================
diff --git a/MAINTAINERS b/MAINTAINERS
index 031c743e979521a92ed9ac67915c178ce31727bd..d6a6745e2dae29c3b8f80bbe61c54a2f5ecd9f47 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15585,6 +15585,8 @@ L:	linux-hwmon@vger.kernel.org
 S:	Supported
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml
+F:	Documentation/hwmon/max20830.rst
+F:	drivers/hwmon/pmbus/max20830.c
 
 MAX2175 SDR TUNER DRIVER
 M:	Ramesh Shanmugasundaram <rashanmu@gmail.com>
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 8f4bff375ecbc355f5ed3400855c2852ec2aa5ef..987705bf45b75b7b91ccc469247909f3c3f53d77 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -365,6 +365,15 @@ config SENSORS_MAX20751
 	  This driver can also be built as a module. If so, the module will
 	  be called max20751.
 
+config SENSORS_MAX20830
+	tristate "Analog Devices MAX20830"
+	help
+	  If you say yes here you get hardware monitoring support for Analog
+	  Devices MAX20830.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called max20830.
+
 config SENSORS_MAX31785
 	tristate "Maxim MAX31785 and compatibles"
 	help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 7129b62bc00f8a2e98de14004997752a856dfda2..bc52f930e0825a902a0dd1c9e2b44f2e8d577c35 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_SENSORS_MAX16601)	+= max16601.o
 obj-$(CONFIG_SENSORS_MAX17616)	+= max17616.o
 obj-$(CONFIG_SENSORS_MAX20730)	+= max20730.o
 obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o
+obj-$(CONFIG_SENSORS_MAX20830)	+= max20830.o
 obj-$(CONFIG_SENSORS_MAX31785)	+= max31785.o
 obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
 obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
diff --git a/drivers/hwmon/pmbus/max20830.c b/drivers/hwmon/pmbus/max20830.c
new file mode 100644
index 0000000000000000000000000000000000000000..bcf60fd948e3437f47267747547142704ae96378
--- /dev/null
+++ b/drivers/hwmon/pmbus/max20830.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hardware monitoring driver for Analog Devices MAX20830
+ *
+ * Copyright (C) 2026 Analog Devices, Inc.
+ */
+
+#include <linux/i2c.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include "pmbus.h"
+
+static struct pmbus_driver_info max20830_info = {
+	.pages = 1,
+	.format[PSC_VOLTAGE_IN] = linear,
+	.format[PSC_VOLTAGE_OUT] = linear,
+	.format[PSC_CURRENT_OUT] = linear,
+	.format[PSC_TEMPERATURE] = linear,
+	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT |
+		PMBUS_HAVE_TEMP |
+		PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
+		PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+};
+
+static int max20830_probe(struct i2c_client *client)
+{
+	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
+	int ret;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
+		return -ENODEV;
+
+	ret = i2c_smbus_read_i2c_block_data(client, PMBUS_IC_DEVICE_ID,
+					    I2C_SMBUS_BLOCK_MAX, buf);
+	if (ret < 0)
+		return dev_err_probe(&client->dev, ret,
+				     "Failed to read IC_DEVICE_ID\n");
+
+	buf[ret] = '\0';
+	if (ret < 9 || strncmp(buf + 1, "MAX20830", 8))
+		return dev_err_probe(&client->dev, -ENODEV,
+				     "Unsupported device: '%s'\n", buf);
+
+	return pmbus_do_probe(client, &max20830_info);
+}
+
+static const struct i2c_device_id max20830_id[] = {
+	{"max20830"},
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max20830_id);
+
+static const struct of_device_id max20830_of_match[] = {
+	{ .compatible = "adi,max20830" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max20830_of_match);
+
+static struct i2c_driver max20830_driver = {
+	.driver = {
+		.name = "max20830",
+		.of_match_table = max20830_of_match,
+	},
+	.probe = max20830_probe,
+	.id_table = max20830_id,
+};
+
+module_i2c_driver(max20830_driver);
+
+MODULE_AUTHOR("Alexis Czezar Torreno <alexisczezar.torreno@analog.com>");
+MODULE_DESCRIPTION("PMBus driver for Analog Devices MAX20830");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);

-- 
2.34.1

Re: [PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

[sashiko-bot]

Sashiko AI review found 3 potential issue(s):
- [Medium] The driver incorrectly uses `i2c_smbus_read_i2c_block_data` instead of `i2c_smbus_read_block_data`, violating the protocol and logging an untrusted binary buffer.
- [Low] The MODULE_IMPORT_NS macro uses an unquoted identifier, resulting in a build failure.
- [Low] The sysfs attribute `in2_alarm` is created but not documented.
--

commit 62ed9b8ac37c74adac303a0ebaea8df41fde6a85
Author: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>

hwmon: (pmbus/max20830) add driver for max20830

This commit adds support for the Analog Devices MAX20830 step-down DC-DC
switching regulator. It provides a PMBus client driver to monitor input and
output voltages, output current, and temperature.

> diff --git a/Documentation/hwmon/max20830.rst b/Documentation/hwmon/max20830.rst
> new file mode 100644
> index 0000000000000..b9dffb7605978
> --- /dev/null
> +++ b/Documentation/hwmon/max20830.rst
[ ... ]
> +================= ========================================
> +in1_label         "vin"
> +in1_input         Measured input voltage
> +in1_alarm         Input voltage alarm
> +in2_label         "vout1"
> +in2_input         Measured output voltage

This isn't a bug, but since the driver configuration enables
PMBUS_HAVE_STATUS_VOUT, it will expose the in2_alarm attribute. Should
in2_alarm be documented here alongside the other alarms?

> +curr1_label       "iout1"
> +curr1_input       Measured output current
> +curr1_alarm       Output current alarm
> +temp1_input       Measured temperature
> +temp1_alarm       Chip temperature alarm
> +================= ========================================

> diff --git a/drivers/hwmon/pmbus/max20830.c b/drivers/hwmon/pmbus/max20830.c
> new file mode 100644
> index 0000000000000..bcf60fd948e34
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/max20830.c
[ ... ]
> +static int max20830_probe(struct i2c_client *client)
> +{
> +	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
> +	int ret;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
> +		return -ENODEV;
> +
> +	ret = i2c_smbus_read_i2c_block_data(client, PMBUS_IC_DEVICE_ID,
> +					    I2C_SMBUS_BLOCK_MAX, buf);

Should this use i2c_smbus_read_block_data() instead?

PMBus IC_DEVICE_ID is an SMBus Block Read command, which natively returns a
length byte followed by the data. Using the I2C block read API with a
hardcoded length of 32 forces an over-read and captures the raw SMBus length
byte in buf[0].

> +	if (ret < 0)
> +		return dev_err_probe(&client->dev, ret,
> +				     "Failed to read IC_DEVICE_ID\n");
> +
> +	buf[ret] = '\0';
> +	if (ret < 9 || strncmp(buf + 1, "MAX20830", 8))
> +		return dev_err_probe(&client->dev, -ENODEV,
> +				     "Unsupported device: '%s'\n", buf);

If the device is unsupported, will logging the buffer via %s print unprintable
characters?

Since buf[0] contains the raw length byte from the block read, this could
inject control characters and trailing binary padding into the kernel log.

[ ... ]
> +MODULE_AUTHOR("Alexis Czezar Torreno <alexisczezar.torreno@analog.com>");
> +MODULE_DESCRIPTION("PMBus driver for Analog Devices MAX20830");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS(PMBUS);

Will this cause a build failure?

The MODULE_IMPORT_NS macro expects a string literal. Should PMBUS be enclosed
in quotes, like MODULE_IMPORT_NS("PMBUS")?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260414-dev_max20830-v1-0-210d3f82c571@analog.com?part=2

Re: [PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

[Guenter Roeck]

On 4/13/26 21:56, sashiko-bot@kernel.org wrote:
> Sashiko AI review found 3 potential issue(s):
> - [Medium] The driver incorrectly uses `i2c_smbus_read_i2c_block_data` instead of `i2c_smbus_read_block_data`, violating the protocol and logging an untrusted binary buffer.
> - [Low] The MODULE_IMPORT_NS macro uses an unquoted identifier, resulting in a build failure.
> - [Low] The sysfs attribute `in2_alarm` is created but not documented.
> --
> 

The reported issues seem real. Please address.

Thanks,
Guenter

> commit 62ed9b8ac37c74adac303a0ebaea8df41fde6a85
> Author: Alexis Czezar Torreno <alexisczezar.torreno@analog.com>
> 
> hwmon: (pmbus/max20830) add driver for max20830
> 
> This commit adds support for the Analog Devices MAX20830 step-down DC-DC
> switching regulator. It provides a PMBus client driver to monitor input and
> output voltages, output current, and temperature.
> 
>> diff --git a/Documentation/hwmon/max20830.rst b/Documentation/hwmon/max20830.rst
>> new file mode 100644
>> index 0000000000000..b9dffb7605978
>> --- /dev/null
>> +++ b/Documentation/hwmon/max20830.rst
> [ ... ]
>> +================= ========================================
>> +in1_label         "vin"
>> +in1_input         Measured input voltage
>> +in1_alarm         Input voltage alarm
>> +in2_label         "vout1"
>> +in2_input         Measured output voltage
> 
> This isn't a bug, but since the driver configuration enables
> PMBUS_HAVE_STATUS_VOUT, it will expose the in2_alarm attribute. Should
> in2_alarm be documented here alongside the other alarms?
> 
>> +curr1_label       "iout1"
>> +curr1_input       Measured output current
>> +curr1_alarm       Output current alarm
>> +temp1_input       Measured temperature
>> +temp1_alarm       Chip temperature alarm
>> +================= ========================================
> 
>> diff --git a/drivers/hwmon/pmbus/max20830.c b/drivers/hwmon/pmbus/max20830.c
>> new file mode 100644
>> index 0000000000000..bcf60fd948e34
>> --- /dev/null
>> +++ b/drivers/hwmon/pmbus/max20830.c
> [ ... ]
>> +static int max20830_probe(struct i2c_client *client)
>> +{
>> +	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
>> +	int ret;
>> +
>> +	if (!i2c_check_functionality(client->adapter,
>> +				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
>> +		return -ENODEV;
>> +
>> +	ret = i2c_smbus_read_i2c_block_data(client, PMBUS_IC_DEVICE_ID,
>> +					    I2C_SMBUS_BLOCK_MAX, buf);
> 
> Should this use i2c_smbus_read_block_data() instead?
> 
> PMBus IC_DEVICE_ID is an SMBus Block Read command, which natively returns a
> length byte followed by the data. Using the I2C block read API with a
> hardcoded length of 32 forces an over-read and captures the raw SMBus length
> byte in buf[0].
> 
>> +	if (ret < 0)
>> +		return dev_err_probe(&client->dev, ret,
>> +				     "Failed to read IC_DEVICE_ID\n");
>> +
>> +	buf[ret] = '\0';
>> +	if (ret < 9 || strncmp(buf + 1, "MAX20830", 8))
>> +		return dev_err_probe(&client->dev, -ENODEV,
>> +				     "Unsupported device: '%s'\n", buf);
> 
> If the device is unsupported, will logging the buffer via %s print unprintable
> characters?
> 
> Since buf[0] contains the raw length byte from the block read, this could
> inject control characters and trailing binary padding into the kernel log.
> 
> [ ... ]
>> +MODULE_AUTHOR("Alexis Czezar Torreno <alexisczezar.torreno@analog.com>");
>> +MODULE_DESCRIPTION("PMBus driver for Analog Devices MAX20830");
>> +MODULE_LICENSE("GPL");
>> +MODULE_IMPORT_NS(PMBUS);
> 
> Will this cause a build failure?
> 
> The MODULE_IMPORT_NS macro expects a string literal. Should PMBUS be enclosed
> in quotes, like MODULE_IMPORT_NS("PMBUS")?
> 

RE: [PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

[Torreno, Alexis Czezar]

> On 4/13/26 21:56, sashiko-bot@kernel.org wrote:
> > Sashiko AI review found 3 potential issue(s):
> > - [Medium] The driver incorrectly uses `i2c_smbus_read_i2c_block_data`
> instead of `i2c_smbus_read_block_data`, violating the protocol and logging an
> untrusted binary buffer.
> > - [Low] The MODULE_IMPORT_NS macro uses an unquoted identifier,
> resulting in a build failure.
> > - [Low] The sysfs attribute `in2_alarm` is created but not documented.
> > --
> >
> 
> The reported issues seem real. Please address.
> 

Will fix the missing in2_alarm and lacking quotes in MODULE_IMPORT_NS macro

I may need to keep i2c_smbus_read_i2c_block_data. I'm testing this on an rpi4 and
it seems i2c_smbus_read_block_data isn't supported by the adapter.

Regards,
Alexis

Re: [PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

[Guenter Roeck]

Hi,

On 4/14/26 19:21, Torreno, Alexis Czezar wrote:
>> On 4/13/26 21:56, sashiko-bot@kernel.org wrote:
>>> Sashiko AI review found 3 potential issue(s):
>>> - [Medium] The driver incorrectly uses `i2c_smbus_read_i2c_block_data`
>> instead of `i2c_smbus_read_block_data`, violating the protocol and logging an
>> untrusted binary buffer.
>>> - [Low] The MODULE_IMPORT_NS macro uses an unquoted identifier,
>> resulting in a build failure.
>>> - [Low] The sysfs attribute `in2_alarm` is created but not documented.
>>> --
>>>
>>
>> The reported issues seem real. Please address.
>>
> 
> Will fix the missing in2_alarm and lacking quotes in MODULE_IMPORT_NS macro
> 
> I may need to keep i2c_smbus_read_i2c_block_data. I'm testing this on an rpi4 and
> it seems i2c_smbus_read_block_data isn't supported by the adapter.
> 

Odd. I can see that the bcm2835 controller driver sets I2C_FUNC_SMBUS_EMUL
but not I2C_FUNC_SMBUS_BLOCK_DATA. That makes me wonder if the controller
really does not support block reads. Any chance you can try setting that
flag in ./drivers/i2c/busses/i2c-bcm2835.c and see what happens ?

Thanks,
Guenter

RE: [PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

[Torreno, Alexis Czezar]

> >>> Sashiko AI review found 3 potential issue(s):
> >>> - [Medium] The driver incorrectly uses
> >>> `i2c_smbus_read_i2c_block_data`
> >> instead of `i2c_smbus_read_block_data`, violating the protocol and
> >> logging an untrusted binary buffer.
> >>> - [Low] The MODULE_IMPORT_NS macro uses an unquoted identifier,
> >> resulting in a build failure.
> >>> - [Low] The sysfs attribute `in2_alarm` is created but not documented.
> >>> --
> >>>
> >>
> >> The reported issues seem real. Please address.
> >>
> >
> > Will fix the missing in2_alarm and lacking quotes in MODULE_IMPORT_NS
> > macro
> >
> > I may need to keep i2c_smbus_read_i2c_block_data. I'm testing this on
> > an rpi4 and it seems i2c_smbus_read_block_data isn't supported by the
> adapter.
> >
> 
> Odd. I can see that the bcm2835 controller driver sets
> I2C_FUNC_SMBUS_EMUL but not I2C_FUNC_SMBUS_BLOCK_DATA. That
> makes me wonder if the controller really does not support block reads. Any
> chance you can try setting that flag in ./drivers/i2c/busses/i2c-bcm2835.c and
> see what happens ?
> 

Sure, let me try this soon and get back to you on the results. 

RE: [PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

[Torreno, Alexis Czezar]

> >
> > I may need to keep i2c_smbus_read_i2c_block_data. I'm testing this on
> > an rpi4 and it seems i2c_smbus_read_block_data isn't supported by the
> adapter.
> >
> 
> Odd. I can see that the bcm2835 controller driver sets
> I2C_FUNC_SMBUS_EMUL but not I2C_FUNC_SMBUS_BLOCK_DATA. That
> makes me wonder if the controller really does not support block reads. Any
> chance you can try setting that flag in ./drivers/i2c/busses/i2c-bcm2835.c and
> see what happens ?
> 

I tried using i2c_smbus_read_block_data, and here's some log messages 

[ 6857.261998] max20830: adapter does NOT support I2C_FUNC_SMBUS_BLOCK_DATA
[ 6857.262006] max20830: adapter supports I2C_FUNC_SMBUS_READ_I2C_BLOCK
[ 6857.265228] max20830: i2c_block_data read 32 bytes: '        MAX20830'
[ 6857.265648] max20830: smbus_block_data read 9 bytes: ''

i2c_smbus_read_i2c_block_data returns 32 for 32 bytes read
and the buffer content is expected "MAX20830"

i2c_smbus_read_block_data returned 9 so I think it read the payload length of 1byte
but no data beyond it, hence buffer = ''

Re: [PATCH 2/2] hwmon: (pmbus/max20830) add driver for max20830

[Guenter Roeck]

On 4/15/26 20:04, Torreno, Alexis Czezar wrote:
>>>
>>> I may need to keep i2c_smbus_read_i2c_block_data. I'm testing this on
>>> an rpi4 and it seems i2c_smbus_read_block_data isn't supported by the
>> adapter.
>>>
>>
>> Odd. I can see that the bcm2835 controller driver sets
>> I2C_FUNC_SMBUS_EMUL but not I2C_FUNC_SMBUS_BLOCK_DATA. That
>> makes me wonder if the controller really does not support block reads. Any
>> chance you can try setting that flag in ./drivers/i2c/busses/i2c-bcm2835.c and
>> see what happens ?
>>
> 
> I tried using i2c_smbus_read_block_data, and here's some log messages
> 
> [ 6857.261998] max20830: adapter does NOT support I2C_FUNC_SMBUS_BLOCK_DATA
> [ 6857.262006] max20830: adapter supports I2C_FUNC_SMBUS_READ_I2C_BLOCK
> [ 6857.265228] max20830: i2c_block_data read 32 bytes: '        MAX20830'
> [ 6857.265648] max20830: smbus_block_data read 9 bytes: ''
> 
> i2c_smbus_read_i2c_block_data returns 32 for 32 bytes read
> and the buffer content is expected "MAX20830"
> 
> i2c_smbus_read_block_data returned 9 so I think it read the payload length of 1byte
> but no data beyond it, hence buffer = ''
> 

Ok, worth a try. The "correct" fix would be to implement support for the command
in the I2C controller driver, but that would be too much to ask for.

Ok to use i2c_smbus_read_i2c_block_data, but please add a comment describing
the reason, i.e., that this is to support drivers/controllers which don't support
i2c_smbus_read_block_data(). Also, please implement code to address the
differences: The first returned byte is the real length, so please check that.
Also, please fix the "Unsupported device" log to not print the first byte.

Thanks,
Guenter