[PATCH v2 0/2] Add support for HiTRON HAC300S PSU

[PATCH v2 0/2] Add support for HiTRON HAC300S PSU

[Vasileios Amoiridis]

From: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>

Changes in v2:
--------------

Patch 1/2:
	- fixed type
	- Added Ack-By

Patch 2/2:
	- removed if statement for VOUT_MODE reg
	- device specific read_word_data function reads only affected
	  registers and returns -ENODATA
	- fixed typos

v1:
---

Add support for the HiTRON HAC300S AC/DC switching power supply in
compact PCI format, with a 300W rating. This is a simple PMBUS
compatible device.

There is a small caveat with the internal registers of the device and
more specifically with the PMBUS_VOUT_MODE. As it is already described
in the driver, the device does not support the PMBUS_VOUT_MODE register
and at the same time, it returns the voltage output values in Linear11
which is not adhering to the PMBus specification (PMBus Specification
Part II, Section 7.1-7.3). For that reason the PMBUS_VOUT_MODE register
is being faked and returns the exponent value of the READ_VOUT register.
The exponent part of the VOUT_* registers is being cleard in order to
return the mantissa to the pmbus core.

Vasileios Amoiridis (2):
  dt-bindings: trivial-devices: Add hitron,hac300s
  hwmon: Add support for HiTRON HAC300S PSU

 .../devicetree/bindings/trivial-devices.yaml  |   2 +
 .../devicetree/bindings/vendor-prefixes.yaml  |   2 +
 Documentation/hwmon/hac300s.rst               |  37 +++++
 Documentation/hwmon/index.rst                 |   1 +
 MAINTAINERS                                   |   7 +
 drivers/hwmon/pmbus/Kconfig                   |   9 ++
 drivers/hwmon/pmbus/Makefile                  |   1 +
 drivers/hwmon/pmbus/hac300s.c                 | 132 ++++++++++++++++++
 8 files changed, 191 insertions(+)
 create mode 100644 Documentation/hwmon/hac300s.rst
 create mode 100644 drivers/hwmon/pmbus/hac300s.c

-- 
2.47.3

[PATCH v2 1/2] dt-bindings: trivial-devices: Add hitron,hac300s

[Vasileios Amoiridis]

From: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>

Add HiTRON HAC300S PSU to trivial devices since it is simple PMBUS
capable device.

Since this is the first supported device from this vendor, document its
name to the vendor-prefixes.yaml file as well.

Signed-off-by: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
---
 Documentation/devicetree/bindings/trivial-devices.yaml | 2 ++
 Documentation/devicetree/bindings/vendor-prefixes.yaml | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/trivial-devices.yaml b/Documentation/devicetree/bindings/trivial-devices.yaml
index d0f7dbf15d6f..efa1957948a5 100644
--- a/Documentation/devicetree/bindings/trivial-devices.yaml
+++ b/Documentation/devicetree/bindings/trivial-devices.yaml
@@ -123,6 +123,8 @@ properties:
           - fsl,mma8450
             # MPR121: Proximity Capacitive Touch Sensor Controller
           - fsl,mpr121
+            # HiTRON AC/DC CompactPCI Power Supply
+          - hitron,hac300s
             # Honeywell Humidicon HIH-6130 humidity/temperature sensor
           - honeywell,hi6130
             # IBM Common Form Factor Power Supply Versions (all versions)
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.yaml b/Documentation/devicetree/bindings/vendor-prefixes.yaml
index c7591b2aec2a..fdb11141e597 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.yaml
+++ b/Documentation/devicetree/bindings/vendor-prefixes.yaml
@@ -701,6 +701,8 @@ patternProperties:
     description: Hitachi Ltd.
   "^hitex,.*":
     description: Hitex Development Tools
+  "^hitron,.*":
+    description: HiTRON Electronics Corporation
   "^holt,.*":
     description: Holt Integrated Circuits, Inc.
   "^holtek,.*":
-- 
2.47.3

[PATCH v2 2/2] hwmon: Add support for HiTRON HAC300S PSU

[Vasileios Amoiridis]

From: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>

Add Support for HiTRON HAC300S PSU. This is a AC/DC hot-swappable
CompactPCI Serial Dual output active current sharing switching power
supply with a 312W rating.

Signed-off-by: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>
---
 Documentation/hwmon/hac300s.rst |  37 +++++++++
 Documentation/hwmon/index.rst   |   1 +
 MAINTAINERS                     |   7 ++
 drivers/hwmon/pmbus/Kconfig     |   9 +++
 drivers/hwmon/pmbus/Makefile    |   1 +
 drivers/hwmon/pmbus/hac300s.c   | 132 ++++++++++++++++++++++++++++++++
 6 files changed, 187 insertions(+)
 create mode 100644 Documentation/hwmon/hac300s.rst
 create mode 100644 drivers/hwmon/pmbus/hac300s.c

diff --git a/Documentation/hwmon/hac300s.rst b/Documentation/hwmon/hac300s.rst
new file mode 100644
index 000000000000..8b11d3e72295
--- /dev/null
+++ b/Documentation/hwmon/hac300s.rst
@@ -0,0 +1,37 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver hac300s
+=====================
+
+Supported chips:
+
+   * HiTRON HAC300S
+
+     Prefix: 'hac300s'
+
+     Datasheet: Publicly available at HiTRON website.
+
+Author:
+
+  - Vasileios Amoiridis <vasileios.amoiridis@cern.ch>
+
+Description
+-----------
+
+This driver supports the HiTRON HAC300S PSU. It is a Universal AC input
+harmonic correction AC-DC hot-swappable CompactPCI Serial Dual output
+(with 5V standby) 312 Watts active current sharing switching power supply.
+
+The device has an input of 90-264VAC and 2 nominal output voltaged at 12V and
+5V which they can supplu up to 25A and 2.5A respectively.
+
+Sysfs entries
+-------------
+
+======= ==========================================
+curr1   Output current
+in1     Output voltage
+power1  Output power
+temp1   Ambient temperature inside the module
+temp2   Internal secondary component's temperature
+======= ==========================================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 85d7a686883e..f00ce656e9dd 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -84,6 +84,7 @@ Hardware Monitoring Kernel Drivers
    gl518sm
    gpd-fan
    gxp-fan-ctrl
+   hac300s
    hih6130
    hp-wmi-sensors
    hs3001
diff --git a/MAINTAINERS b/MAINTAINERS
index cf755238c429..e4b4a41a2c07 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11259,6 +11259,13 @@ F:	kernel/time/timer_list.c
 F:	kernel/time/timer_migration.*
 F:	tools/testing/selftests/timers/
 
+HITRON HAC300S PSU DRIVER
+M:	Vasileios Amoiridis <vasileios.amoiridis@cern.ch>
+L:	linux-hwmon@vger.kernel.org
+S:	Maintained
+F:	Documentation/hwmon/hac300s.rst
+F:	drivers/hwmon/pmbus/hac300s.c
+
 DELAY, SLEEP, TIMEKEEPING, TIMERS [RUST]
 M:	Andreas Hindborg <a.hindborg@kernel.org>
 R:	Boqun Feng <boqun.feng@gmail.com>
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index f3fb94cebf1a..4c2cb51dbe3f 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -124,6 +124,15 @@ config SENSORS_FSP_3Y
 	  This driver can also be built as a module. If so, the module will
 	  be called fsp-3y.
 
+config SENSORS_HAC300S
+	tristate "Hitron HAC300S-D120E PSU"
+	help
+	  If you say yes here you get hardware monitoring support for the
+	  Hitron HAC300S-D120E Power Supply.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called hac300s.
+
 config SENSORS_IBM_CFFPS
 	tristate "IBM Common Form Factor Power Supply"
 	depends on LEDS_CLASS
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index 349a89b6d92e..b92309019d35 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_SENSORS_BEL_PFE)	+= bel-pfe.o
 obj-$(CONFIG_SENSORS_BPA_RS600)	+= bpa-rs600.o
 obj-$(CONFIG_SENSORS_DELTA_AHE50DC_FAN) += delta-ahe50dc-fan.o
 obj-$(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_INA233)	+= ina233.o
diff --git a/drivers/hwmon/pmbus/hac300s.c b/drivers/hwmon/pmbus/hac300s.c
new file mode 100644
index 000000000000..26cb7fadd5d5
--- /dev/null
+++ b/drivers/hwmon/pmbus/hac300s.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2024 CERN (home.cern)
+/*
+ * Hardware monitoring driver for Hi-Tron HAC300S PSU.
+ *
+ * NOTE: The HAC300S device does not support the PMBUS_VOUT_MODE register.
+ * On top of that, it returns the Voltage output values in Linear11 which is
+ * not adhering to the PMBus specifications. (PMBus Specification Part II,
+ * Section 7.1-7.3). For that reason the PMBUS_VOUT_MODE register is being faked
+ * and returns the exponent value of the READ_VOUT register. The exponent part
+ * of the VOUT_* registers is being cleared in order to return the mantissa to
+ * the pmbus core.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pmbus.h>
+
+#include "pmbus.h"
+
+#define LINEAR11_EXPONENT_MASK GENMASK(15, 11)
+#define LINEAR11_MANTISSA_MASK GENMASK(10, 0)
+
+#define to_hac300s_data(x) container_of(x, struct hac300s_data, info)
+
+struct hac300s_data {
+	struct pmbus_driver_info info;
+	s8 exponent;
+};
+
+static int hac300s_read_byte_data(struct i2c_client *client, int page, int reg)
+{
+	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+	struct hac300s_data *data = to_hac300s_data(info);
+
+	if (reg == PMBUS_VOUT_MODE)
+		return data->exponent;
+
+	return pmbus_read_byte_data(client, page, reg);
+}
+
+static int hac300s_read_word_data(struct i2c_client *client, int page,
+				   int phase, int reg)
+{
+	int rv;
+
+	switch (reg) {
+	case PMBUS_VOUT_OV_WARN_LIMIT:
+	case PMBUS_VOUT_UV_WARN_LIMIT:
+	case PMBUS_VOUT_OV_FAULT_LIMIT:
+	case PMBUS_VOUT_UV_FAULT_LIMIT:
+	case PMBUS_MFR_VOUT_MAX:
+	case PMBUS_MFR_VOUT_MIN:
+	case PMBUS_READ_VOUT:
+		rv = pmbus_read_word_data(client, page, phase, reg);
+		return FIELD_GET(LINEAR11_MANTISSA_MASK, rv);
+	default:
+		return -ENODATA;
+	}
+}
+
+static struct pmbus_driver_info hac300s_info = {
+	.pages = 1,
+	.func[0] = (PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 | \
+                    PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | \
+                    PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | \
+                    PMBUS_HAVE_POUT | PMBUS_HAVE_STATUS_TEMP),
+	.read_byte_data = hac300s_read_byte_data,
+	.read_word_data = hac300s_read_word_data,
+	.format[PSC_VOLTAGE_OUT] = linear,
+};
+
+static struct pmbus_platform_data hac300s_pdata = {
+	.flags = PMBUS_NO_CAPABILITY,
+};
+
+static int hac300s_probe(struct i2c_client *client)
+{
+	struct hac300s_data *data;
+	int rv;
+
+	data = devm_kzalloc(&client->dev, sizeof(struct hac300s_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	if (!i2c_check_functionality(client->adapter,
+				     I2C_FUNC_SMBUS_READ_BYTE_DATA |
+				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+		return -ENODEV;
+
+	rv = i2c_smbus_read_word_data(client, PMBUS_READ_VOUT);
+	if (rv < 0)
+		return dev_err_probe(&client->dev, rv, "Failed to read vout_mode\n");
+
+	data->exponent = FIELD_GET(LINEAR11_EXPONENT_MASK, rv);
+	data->info = hac300s_info;
+	client->dev.platform_data = &hac300s_pdata;
+	return pmbus_do_probe(client, &data->info);
+}
+
+static const struct of_device_id hac300s_of_match[] = {
+	{ .compatible = "hitron,hac300s" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, hac300s_of_match);
+
+static const struct i2c_device_id hac300s_id[] = {
+	{"hac300s", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, hac300s_id);
+
+static struct i2c_driver hac300s_driver = {
+	.driver = {
+		   .name = "hac300s",
+		   .of_match_table = hac300s_of_match,
+	},
+	.probe = hac300s_probe,
+	.id_table = hac300s_id,
+
+};
+module_i2c_driver(hac300s_driver);
+
+MODULE_AUTHOR("Vasileios Amoiridis");
+MODULE_DESCRIPTION("PMBus driver for Hi-Tron HAC300S PSU");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("PMBUS");
-- 
2.47.3

Re: [PATCH v2 1/2] dt-bindings: trivial-devices: Add hitron,hac300s

[Guenter Roeck]

On Mon, Jan 19, 2026 at 08:08:05PM +0100, Vasileios Amoiridis wrote:
> From: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>
> 
> Add HiTRON HAC300S PSU to trivial devices since it is simple PMBUS
> capable device.
> 
> Since this is the first supported device from this vendor, document its
> name to the vendor-prefixes.yaml file as well.
> 
> Signed-off-by: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>
> Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

Applied.

Thanks,
Guenter

Re: [PATCH v2 2/2] hwmon: Add support for HiTRON HAC300S PSU

[Guenter Roeck]

On Mon, Jan 19, 2026 at 08:08:06PM +0100, Vasileios Amoiridis wrote:
> From: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>
> 
> Add Support for HiTRON HAC300S PSU. This is a AC/DC hot-swappable
> CompactPCI Serial Dual output active current sharing switching power
> supply with a 312W rating.
> 
> Signed-off-by: Vasileios Amoiridis <vasileios.amoiridis@cern.ch>

checkpatch --strict returns various whitespace errors. Please run that
command in the future.

Also,

> +static int hac300s_read_byte_data(struct i2c_client *client, int page, int reg)
> +{
> +	const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
> +	struct hac300s_data *data = to_hac300s_data(info);
> +
> +	if (reg == PMBUS_VOUT_MODE)
> +		return data->exponent;
> +
> +	return pmbus_read_byte_data(client, page, reg);

This should return -ENODATA.

No need to resend; I fixed it all up and applied the patch.

Thanks,
Guenter