[PATCH v4 0/3] add support for Delta E50SN12051

[PATCH v4 0/3] add support for Delta E50SN12051

[Colin Huang via B4 Relay]

Delta E50SN12051 is a 600W non-isolated 1/8th brick DC-DC power module.
With this series applied, voltage, current and temperature sensors can 
be exposed through the standard hwmon interface.

Changes in this series:
- Introduce device-tree binding documentation for the new device
- Add hwmon documentation describing the supported sensors
- Add PMBus driver support for Delta E50SN12051

Signed-off-by: Colin Huang <u8813345@gmail.com>
---
Changes in v4:
- Rewrite binding description to be hardware-centric and OS-agnostic.
- Rename example node from hwmon@40 to a generic power-module@40.
- Link to v3: https://lore.kernel.org/r/20260430-add-e50sn12051-v3-0-f6d4e043ec7c@gmail.com

Changes in v3:
- Simplify to pass &e50sn12051_info directly to pmbus_do_probe() 
  to avoid the extra memory allocation
- Link to v2: https://lore.kernel.org/r/20260430-add-e50sn12051-v2-0-d76fe42482ab@gmail.com

Changes in v2:
- Add %YAML 1.2 declaration in binding document.
- Use a generic node name in examples in binding document.
- Add MODULE_IMPORT_NS("PMBUS")
- Remove unused / incorrect headers
- Link to v1: https://lore.kernel.org/r/20260429-add-e50sn12051-v1-0-c101e6c80bbb@gmail.com

---
Colin Huang (3):
      dt-bindings: hwmon: pmbus: add Delta E50SN12051 binding
      Documentation/hwmon: add Delta E50SN12051 documentation
      hwmon: (pmbus) add support for Delta E50SN12051

 .../bindings/hwmon/pmbus/delta,e50sn12051.yaml     | 42 +++++++++++
 Documentation/hwmon/e50sn12051.rst                 | 81 ++++++++++++++++++++++
 Documentation/hwmon/index.rst                      |  1 +
 drivers/hwmon/pmbus/Kconfig                        |  9 +++
 drivers/hwmon/pmbus/Makefile                       |  1 +
 drivers/hwmon/pmbus/e50sn12051.c                   | 52 ++++++++++++++
 6 files changed, 186 insertions(+)
---
base-commit: b584e7d50af502462349910bf4ed30057620b69f
change-id: 20260316-add-e50sn12051-ad828ad6777a

Best regards,
-- 
Colin Huang <u8813345@gmail.com>

[PATCH v4 1/3] dt-bindings: hwmon: pmbus: add Delta E50SN12051 binding

[Colin Huang via B4 Relay]

From: Colin Huang <u8813345@gmail.com>

Add devicetree binding documentation for the Delta E50SN12051
PMBus-compliant device.

Signed-off-by: Colin Huang <u8813345@gmail.com>
---
 .../bindings/hwmon/pmbus/delta,e50sn12051.yaml     | 42 ++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml
new file mode 100644
index 000000000000..72aefe212d17
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/pmbus/delta,e50sn12051.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Delta E50SN12051 PMBus Sensor
+
+maintainers:
+  - Kevin Chang <kevin.chang2@amd.com>
+
+description: |
+  Delta E50SN12051 is a non-isolated 1/8th brick DC-DC power module.
+  It is a PMBus-compliant device accessible via an I2C/SMBus interface
+  and provides standard telemetry such as voltage, current, and
+  temperature measurements.
+
+properties:
+  compatible:
+    const: delta,e50sn12051
+
+  reg:
+    maxItems: 1
+    description: I2C bus address of the PMBus device
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        power-module@40 {
+            compatible = "delta,e50sn12051";
+            reg = <0x40>;
+        };
+    };

-- 
2.34.1

[PATCH v4 2/3] Documentation/hwmon: add Delta E50SN12051 documentation

[Colin Huang via B4 Relay]

From: Colin Huang <u8813345@gmail.com>

Document the hardware monitoring support for the Delta E50SN12051
device.

The documentation describes the supported sensors exposed via the
hwmon subsystem, including voltage, current, and temperature measurements.

Signed-off-by: Colin Huang <u8813345@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
 Documentation/hwmon/e50sn12051.rst | 81 ++++++++++++++++++++++++++++++++++++++
 Documentation/hwmon/index.rst      |  1 +
 2 files changed, 82 insertions(+)

diff --git a/Documentation/hwmon/e50sn12051.rst b/Documentation/hwmon/e50sn12051.rst
new file mode 100644
index 000000000000..cbbfa7895d82
--- /dev/null
+++ b/Documentation/hwmon/e50sn12051.rst
@@ -0,0 +1,81 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver e50sn12051
+========================
+
+Supported chips:
+
+  * Delta E50SN12051
+
+    Prefix: 'e50sn12051'
+
+    Addresses scanned: -
+
+    Datasheet:
+
+      Provided by Delta upon request and NDA
+
+Description
+-----------
+
+E50SN12051 is a 600W non-isolated 1/8th brick DC-DC power module.
+
+This driver supports the E50SN12051 PMBus compliant monitor device.
+
+The device provides measurements for:
+
+* Input voltage
+* Output current
+* Output voltage
+* Temperature
+
+The driver is based on the PMBus core and exposes standard hwmon
+sysfs attributes.
+
+Sysfs attributes
+----------------
+
+======================= =======================================================
+curr1_label             "iout1"
+curr1_crit              Critical maximum current.
+                        From IOUT_OC_FAULT_LIMIT register.
+curr1_crit_alarm        Current critical high alarm.
+                        From IOUT_OC_FAULT status.
+curr1_input             Measured current.
+                        From READ_IOUT register.
+curr1_max               Maximum current.
+                        From IOUT_OC_WARN_LIMIT register.
+curr1_max_alarm         Current high alarm.
+                        From IOUT_OC_WARN_LIMIT status.
+
+in1_label               "vin"
+in1_alarm               Input voltage alarm.
+in1_input               Measured voltage.
+                        From READ_VIN register.
+
+in2_label               "vout1"
+in2_crit                Critical maximum voltage.
+                        From VOUT_OV_FAULT_LIMIT register.
+in2_crit_alarm          Voltage critical high alarm.
+                        From VOLTAGE_OV_FAULT status.
+in2_input               Measured voltage.
+                        From READ_VOUT register.
+in2_max                 Maximum voltage.
+                        From VOUT_OV_WARN_LIMIT register.
+in2_max_alarm           Voltage high alarm.
+                        From VOLTAGE_OV_WARNING status.
+
+temp1_crit              Critical high temperature.
+                        From OT_FAULT_LIMIT register.
+temp1_crit_alarm        Module temperature critical high alarm.
+                        Set by comparing READ_TEMPERATURE_1 with OT_FAULT_LIMIT
+                        if TEMP_OT_FAULT status is set.
+temp1_input             Measured module's hot spot temperature.
+                        From READ_TEMPERATURE_1 register.
+temp1_max               Maximum temperature.
+                        From OT_WARN_LIMIT register.
+temp1_max_alarm         Module temperature high alarm.
+                        Set by comparing READ_TEMPERATURE_1 with OT_WARN_LIMIT if
+                        TEMP_OT_WARNING status is set.
+======================= =======================================================
+
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 8b655e5d6b68..ba08655fc496 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -68,6 +68,7 @@ Hardware Monitoring Kernel Drivers
    drivetemp
    ds1621
    ds620
+   e50sn12051
    emc1403
    emc2103
    emc2305

-- 
2.34.1

[PATCH v4 3/3] hwmon: (pmbus) add support for Delta E50SN12051

[Colin Huang via B4 Relay]

From: Colin Huang <u8813345@gmail.com>

Add the pmbus driver for Delta E50SN12051 600W Non-isolated
1/8th Brick DCDC Power Modules.

Signed-off-by: Colin Huang <u8813345@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/pmbus/Kconfig      |  9 +++++++
 drivers/hwmon/pmbus/Makefile     |  1 +
 drivers/hwmon/pmbus/e50sn12051.c | 52 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+)

diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 8f4bff375ecb..4fbfcbc4a9c5 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -161,6 +161,15 @@ config SENSORS_DPS920AB
 	  This driver can also be built as a module. If so, the module will
 	  be called dps920ab.
 
+config SENSORS_E50SN12051
+	tristate "Delta E50SN12051 Power Modules"
+	help
+	  If you say yes here you get hardware monitoring support for Delta
+	  E50SN12051 Power Modules.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called e50sn12051.
+
 config SENSORS_INA233
 	tristate "Texas Instruments INA233 and compatibles"
 	help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 7129b62bc00f..fc910bf34fe3 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_SENSORS_FSP_3Y)	+= fsp-3y.o
 obj-$(CONFIG_SENSORS_HAC300S)	+= hac300s.o
 obj-$(CONFIG_SENSORS_IBM_CFFPS)	+= ibm-cffps.o
 obj-$(CONFIG_SENSORS_DPS920AB)	+= dps920ab.o
+obj-$(CONFIG_SENSORS_E50SN12051) += e50sn12051.o
 obj-$(CONFIG_SENSORS_INA233)	+= ina233.o
 obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
 obj-$(CONFIG_SENSORS_IR35221)	+= ir35221.o
diff --git a/drivers/hwmon/pmbus/e50sn12051.c b/drivers/hwmon/pmbus/e50sn12051.c
new file mode 100644
index 000000000000..efb4d62b2603
--- /dev/null
+++ b/drivers/hwmon/pmbus/e50sn12051.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for E50SN12051
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include "pmbus.h"
+
+static struct pmbus_driver_info e50sn12051_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_STATUS_INPUT |
+		   PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT |
+		   PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
+		   PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP,
+};
+
+static const struct i2c_device_id e50sn12051_id[] = { { "e50sn12051", 0 }, {} };
+MODULE_DEVICE_TABLE(i2c, e50sn12051_id);
+
+static const struct of_device_id e50sn12051_of_match[] = {
+	{ .compatible = "delta,e50sn12051" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, e50sn12051_of_match);
+
+static int e50sn12051_probe(struct i2c_client *client)
+{
+	return pmbus_do_probe(client, &e50sn12051_info);
+}
+
+static struct i2c_driver e50sn12051_driver = {
+	.driver = {
+		.name = "e50sn12051",
+		.of_match_table = e50sn12051_of_match,
+	},
+	.probe = e50sn12051_probe,
+
+	.id_table = e50sn12051_id,
+};
+
+module_i2c_driver(e50sn12051_driver);
+
+MODULE_AUTHOR("Kevin Chang <kevin.chang2@amd.com>");
+MODULE_DESCRIPTION("PMBus driver for E50SN12051");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("PMBUS");

-- 
2.34.1

Re: [PATCH v4 1/3] dt-bindings: hwmon: pmbus: add Delta E50SN12051 binding

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 1930 bytes --]

On Thu, May 07, 2026 at 01:12:26PM +0800, Colin Huang via B4 Relay wrote:
> From: Colin Huang <u8813345@gmail.com>
> 
> Add devicetree binding documentation for the Delta E50SN12051
> PMBus-compliant device.
> 
> Signed-off-by: Colin Huang <u8813345@gmail.com>
> ---
>  .../bindings/hwmon/pmbus/delta,e50sn12051.yaml     | 42 ++++++++++++++++++++++
>  1 file changed, 42 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml
> new file mode 100644
> index 000000000000..72aefe212d17
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml
> @@ -0,0 +1,42 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/hwmon/pmbus/delta,e50sn12051.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Delta E50SN12051 PMBus Sensor
> +
> +maintainers:
> +  - Kevin Chang <kevin.chang2@amd.com>
> +
> +description: |
> +  Delta E50SN12051 is a non-isolated 1/8th brick DC-DC power module.
> +  It is a PMBus-compliant device accessible via an I2C/SMBus interface
> +  and provides standard telemetry such as voltage, current, and
> +  temperature measurements.
> +
> +properties:
> +  compatible:
> +    const: delta,e50sn12051
> +
> +  reg:
> +    maxItems: 1
> +    description: I2C bus address of the PMBus device
> +
> +required:
> +  - compatible
> +  - reg

With only these two properties, shouldn't this be in trivial-devices?

> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        power-module@40 {
> +            compatible = "delta,e50sn12051";
> +            reg = <0x40>;
> +        };
> +    };
> 
> -- 
> 2.34.1
> 
> 

[-- Attachment #2: signature.asc --]
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Re: [PATCH v4 1/3] dt-bindings: hwmon: pmbus: add Delta E50SN12051 binding

[Colin Huang]

Conor Dooley <conor@kernel.org> 於 2026年5月8日週五 上午1:07寫道：
>
> On Thu, May 07, 2026 at 01:12:26PM +0800, Colin Huang via B4 Relay wrote:
> > From: Colin Huang <u8813345@gmail.com>
> >
> > Add devicetree binding documentation for the Delta E50SN12051
> > PMBus-compliant device.
> >
> > Signed-off-by: Colin Huang <u8813345@gmail.com>
> > ---
> >  .../bindings/hwmon/pmbus/delta,e50sn12051.yaml     | 42 ++++++++++++++++++++++
> >  1 file changed, 42 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml
> > new file mode 100644
> > index 000000000000..72aefe212d17
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/hwmon/pmbus/delta,e50sn12051.yaml
> > @@ -0,0 +1,42 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/hwmon/pmbus/delta,e50sn12051.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Delta E50SN12051 PMBus Sensor
> > +
> > +maintainers:
> > +  - Kevin Chang <kevin.chang2@amd.com>
> > +
> > +description: |
> > +  Delta E50SN12051 is a non-isolated 1/8th brick DC-DC power module.
> > +  It is a PMBus-compliant device accessible via an I2C/SMBus interface
> > +  and provides standard telemetry such as voltage, current, and
> > +  temperature measurements.
> > +
> > +properties:
> > +  compatible:
> > +    const: delta,e50sn12051
> > +
> > +  reg:
> > +    maxItems: 1
> > +    description: I2C bus address of the PMBus device
> > +
> > +required:
> > +  - compatible
> > +  - reg
>
> With only these two properties, shouldn't this be in trivial-devices?
Thanks for your comment.
I will remove this file, delta,e50sn12051.yaml,
and add device into trivial-devices.yaml.
>
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    i2c {
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        power-module@40 {
> > +            compatible = "delta,e50sn12051";
> > +            reg = <0x40>;
> > +        };
> > +    };
> >
> > --
> > 2.34.1
> >
> >