[PATCH v5 0/2] Add driver for Infineon TDA38740/TDA38725

[PATCH v5 0/2] Add driver for Infineon TDA38740/TDA38725

[Colin Huang]

Signed-off-by: Colin Huang <u8813345@gmail.com>
---
Changes in v5:
- Remove blank line in yaml header.
- Add interrupts property in yaml file.
- Uses a fallback compatible: infineon,tda38725 can be listed as a fallback for infineon,tda38740.
- Removed the driver-local identify callback and its duplicate VOUT_MODE check.
  and set format[PSC_VOLTAGE_OUT] = linear in the static driver info.
- Dropped the per-device tda38740_data allocation/copy path, since there is no longer any runtime mutation of driver info.
  Probe now passes the static tda38740_info directly to pmbus_do_probe().
- Link to v4: https://lore.kernel.org/r/20260910-add-tda38740-and-tda38725-v4-0-dbae7fabce09@gmail.com

Changes in v4:
- Fix the DT binding so that compatible only enumerates the valid
  hardware variants and does not imply a preferred or fallback
  selection policy.
- Remove the vout-scale-micro property and related code.
- Rename the example node to reflect the regulator function.
- Link to v3: https://lore.kernel.org/r/20260910-add-tda38740-and-tda38725-v3-0-3e87637da3d6@gmail.com

Changes in v3:
- Clarify that TDA38725 and TDA38740 share the same PMBus programming
  model, with infineon,tda38740 as the preferred compatible string and
  infineon,tda38725 as a compatibility alias.
- The optional VOUT scaling property with a documented default
  value of 1.0 to support devices that require output-voltage scaling.
- Update the driver to apply the scaling for READ_VOUT.
- Link to v2: https://lore.kernel.org/r/20260907-add-tda38740-and-tda38725-v2-0-1d051d63aa01@gmail.com

Changes in v2:
- Use standard http:// URIs for $id and $schema
- Add maintainers section.
- Use C99 named initializers.
- Link to v1: https://lore.kernel.org/r/20260907-add-tda38740-and-tda38725-v1-0-e2db1b2566b1@gmail.com

---
Colin Huang (2):
      dt-bindings: hwmon: pmbus: Add Infineon tda38740 and tda38725
      hwmon: (pmbus/tda38740) Add driver for Infineon TDA38740/TDA38725

 .../bindings/hwmon/pmbus/infineon,tda38740.yaml    | 55 ++++++++++++++++++
 Documentation/hwmon/index.rst                      |  1 +
 Documentation/hwmon/tda38740.rst                   | 65 ++++++++++++++++++++++
 drivers/hwmon/pmbus/Kconfig                        |  9 +++
 drivers/hwmon/pmbus/Makefile                       |  1 +
 drivers/hwmon/pmbus/tda38740.c                     | 64 +++++++++++++++++++++
 6 files changed, 195 insertions(+)
---
base-commit: ba08432bda66a7889d8f3d1581dabf10f59b25eb
change-id: 20260903-add-tda38740-and-tda38725-32bbb097d41e

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

[PATCH v5 1/2] dt-bindings: hwmon: pmbus: Add Infineon tda38740 and tda38725

[Colin Huang]

From: Colin Huang <u8813345@gmail.com>

Add devicetree bindings for the Infineon TDA38740 and TDA38725
single-voltage synchronous buck regulators with PMBus interface.

Signed-off-by: Colin Huang <u8813345@gmail.com>
---
 .../bindings/hwmon/pmbus/infineon,tda38740.yaml    | 55 ++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38740.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38740.yaml
new file mode 100644
index 000000000000..6733e44c37f6
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/infineon,tda38740.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/pmbus/infineon,tda38740.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Infineon TDA38740 and TDA38725 PMBus Synchronous Buck Regulator
+
+maintainers:
+  - Colin Huang <u8813345@gmail.com>
+
+description: |
+  The Infineon TDA38740/TDA38725 is a 40A/25A single-voltage synchronous
+  buck regulator with a PMBus interface designed for industrial use.
+
+  Datasheet:
+  https://www.infineon.com/row/public/documents/24/49/infineon-tda38740-tda38725-datasheet-en.pdf
+
+properties:
+  compatible:
+    oneOf:
+      - const: infineon,tda38740
+      - items:
+          - const: infineon,tda38725
+          - const: infineon,tda38740
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        regulator@40 {
+            compatible = "infineon,tda38725",
+                         "infineon,tda38740";
+            reg = <0x40>;
+
+            interrupt-parent = <&sgpiom0>;
+            interrupts = <10 IRQ_TYPE_LEVEL_LOW>;
+        };
+    };
+

-- 
2.34.1

[PATCH v5 2/2] hwmon: (pmbus/tda38740) Add driver for Infineon TDA38740/TDA38725

[Colin Huang]

From: Colin Huang <u8813345@gmail.com>

Add a PMBus driver for Infineon TDA38740 and TDA38725
single-voltage synchronous buck regulators.

Signed-off-by: Colin Huang <u8813345@gmail.com>
---
 Documentation/hwmon/index.rst    |  1 +
 Documentation/hwmon/tda38740.rst | 65 ++++++++++++++++++++++++++++++++++++++++
 drivers/hwmon/pmbus/Kconfig      |  9 ++++++
 drivers/hwmon/pmbus/Makefile     |  1 +
 drivers/hwmon/pmbus/tda38740.c   | 64 +++++++++++++++++++++++++++++++++++++++
 5 files changed, 140 insertions(+)

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index f07977a20271..aeff87b3d46d 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -265,6 +265,7 @@ Hardware Monitoring Kernel Drivers
    sy7636a-hwmon
    tc654
    tc74
+   tda38740
    thmc50
    tmp102
    tmp103
diff --git a/Documentation/hwmon/tda38740.rst b/Documentation/hwmon/tda38740.rst
new file mode 100644
index 000000000000..55ce12f14914
--- /dev/null
+++ b/Documentation/hwmon/tda38740.rst
@@ -0,0 +1,65 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+====================================
+Kernel driver tda38740
+====================================
+
+Supported chips:
+  * Infineon TDA38740
+  * Infineon TDA38725
+
+    Prefix: 'tda38740'
+
+    Addresses scanned: -
+
+    Datasheet:
+      https://www.infineon.com/row/public/documents/24/49/infineon-tda38740-tda38725-datasheet-en.pdf
+
+Author: Colin Huang <u8813345@gmail.com>
+
+Description
+-----------
+
+The TDA38740 and TDA38725 are single-output synchronous buck regulators with a
+PMBus interface. They expose basic voltage, current, power and temperature
+telemetry through the standard PMBus hwmon interfaces.
+
+Sysfs entries
+-------------
+
+======================= =======================================================
+curr1_alarm		Input current alarm
+curr1_input		Measured input current
+curr1_label		"iin"
+
+curr2_crit		Critical maximum output current
+curr2_crit_alarm	Output current critical high alarm
+curr2_input		Measured output current
+curr2_label		"iout"
+
+in1_crit		Critical maximum input voltage
+in1_crit_alarm		Input voltage critical high alarm
+in1_input		Measured input voltage
+in1_label		"vin"
+
+in2_crit		Critical maximum output voltage
+in2_crit_alarm		Output voltage critical high alarm
+in2_input		Measured output voltage
+in2_label		"vout"
+in2_lcrit		Critical minimum output voltage
+in2_lcrit_alarm		Output voltage critical low alarm
+
+power1_alarm		Input power alarm
+power1_input		Measured input power
+power1_label		"pin"
+
+power2_input		Measured output power
+power2_label		"pout"
+
+temp1_crit		Critical high temperature
+temp1_crit_alarm	Chip temperature critical high alarm
+temp1_input		Measured temperature
+temp1_max		Maximum temperature
+temp1_max_alarm		Chip temperature high alarm
+======================= =======================================================
+
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index bcfdc4ce4c10..e4ca80dd0574 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -763,6 +763,15 @@ config SENSORS_TDA38640_REGULATOR
 	  If you say yes here you get regulator support for Infineon
 	  TDA38640 as regulator.
 
+config SENSORS_TDA38740
+	tristate "Infineon TDA38725/TDA38740"
+	help
+	  If you say yes here you get hardware monitoring support for Infineon
+	  TDA38725 and TDA38740.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called tda38740.
+
 config SENSORS_TPS25990
 	tristate "TI TPS25990"
 	help
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index e288fe72a437..eb06d47816fd 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_SENSORS_STEF48H28)	+= stef48h28.o
 obj-$(CONFIG_SENSORS_SQ24860)	+= sq24860.o
 obj-$(CONFIG_SENSORS_STPDDC60)	+= stpddc60.o
 obj-$(CONFIG_SENSORS_TDA38640)	+= tda38640.o
+obj-$(CONFIG_SENSORS_TDA38740)	+= tda38740.o
 obj-$(CONFIG_SENSORS_TPS25990)	+= tps25990.o
 obj-$(CONFIG_SENSORS_TPS40422)	+= tps40422.o
 obj-$(CONFIG_SENSORS_TPS53679)	+= tps53679.o
diff --git a/drivers/hwmon/pmbus/tda38740.c b/drivers/hwmon/pmbus/tda38740.c
new file mode 100644
index 000000000000..1b981c768645
--- /dev/null
+++ b/drivers/hwmon/pmbus/tda38740.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Hardware monitoring driver for Infineon TDA38725/TDA38740
+ *
+ * Copyright (c) 2023 9elements GmbH
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include "pmbus.h"
+
+static struct pmbus_driver_info tda38740_info = {
+	.pages = 1,
+	.format[PSC_VOLTAGE_IN] = linear,
+	.format[PSC_VOLTAGE_OUT] = linear,
+	.format[PSC_CURRENT_OUT] = linear,
+	.format[PSC_CURRENT_IN] = linear,
+	.format[PSC_POWER] = linear,
+	.format[PSC_TEMPERATURE] = linear,
+	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT
+	    | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
+	    | PMBUS_HAVE_IIN
+	    | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
+	    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
+	    | PMBUS_HAVE_POUT | PMBUS_HAVE_PIN,
+};
+
+static int tda38740_probe(struct i2c_client *client)
+{
+	return pmbus_do_probe(client, &tda38740_info);
+}
+
+static const struct i2c_device_id tda38740_id[] = {
+	{ .name = "tda38725"},
+	{ .name = "tda38740"},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, tda38740_id);
+
+static const struct of_device_id __maybe_unused tda38740_of_match[] = {
+	{ .compatible = "infineon,tda38725"},
+	{ .compatible = "infineon,tda38740"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, tda38740_of_match);
+
+static struct i2c_driver tda38740_driver = {
+	.driver = {
+		.name = "tda38740",
+		.of_match_table = of_match_ptr(tda38740_of_match),
+	},
+	.probe = tda38740_probe,
+	.id_table = tda38740_id,
+};
+
+module_i2c_driver(tda38740_driver);
+
+MODULE_DESCRIPTION("PMBus driver for Infineon TDA38725/TDA38740");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("PMBUS");

-- 
2.34.1

Re: [PATCH v5 1/2] dt-bindings: hwmon: pmbus: Add Infineon tda38740 and tda38725

[sashiko-bot]

> From: Colin Huang <u8813345@gmail.com>
> 
> Add devicetree bindings for the Infineon TDA38740 and TDA38725
> single-voltage synchronous buck regulators with PMBus interface.
> 
> Signed-off-by: Colin Huang <u8813345@gmail.com>

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

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260917-add-tda38740-and-tda38725-v5-0-7fc19668ada4@gmail.com?part=1

Re: [PATCH v5 2/2] hwmon: (pmbus/tda38740) Add driver for Infineon TDA38740/TDA38725

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] acpi: of_match_ptr() breaks PRP0001 ACPI matching without CONFIG_OF
--

commit 7b99b2a1da30b603fdd50ea7b04df230634e2572
Author: Colin Huang <u8813345@gmail.com>

hwmon: (pmbus/tda38740) Add driver for Infineon TDA38740/TDA38725

Add a PMBus driver for Infineon TDA38740 and TDA38725
single-voltage synchronous buck regulators.

> diff --git a/drivers/hwmon/pmbus/tda38740.c b/drivers/hwmon/pmbus/tda38740.c
> new file mode 100644
> index 0000000000000..1b981c7686453
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/tda38740.c

[ ... ]

> +static const struct of_device_id __maybe_unused tda38740_of_match[] = {
                                     ^^^^^^^^^^^^^^
[Severity: Medium]
Could we drop this annotation? It appears it is only needed because of the
of_match_ptr() usage below.

> +	{ .compatible = "infineon,tda38725"},
> +	{ .compatible = "infineon,tda38740"},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, tda38740_of_match);
> +
> +static struct i2c_driver tda38740_driver = {
> +	.driver = {
> +		.name = "tda38740",
> +		.of_match_table = of_match_ptr(tda38740_of_match),
                                  ^^^^^^^^^^^^
[Severity: Medium]
Will this break device binding on ACPI-based systems?

When CONFIG_OF is disabled, the of_match_ptr() macro evaluates to NULL. This
strips the of_match_table from the device_driver struct, which prevents the
ACPI subsystem from using the PRP0001 compatible string mechanism to match
and bind the device.

Dropping of_match_ptr() would allow ACPI platforms without OF to still match
using these compatible strings.

> +	},
> +	.probe = tda38740_probe,
> +	.id_table = tda38740_id,
> +};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260917-add-tda38740-and-tda38725-v5-0-7fc19668ada4@gmail.com?part=2