[PATCH v3 1/2] dt-bindings: iio: temperature: Add NXP P3T175x support

[PATCH v3 1/2] dt-bindings: iio: temperature: Add NXP P3T175x support

[Lakshay Piplani]

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Add bindings for the NXP P3T175x (P3T1750/P3T1755) temperature
sensor, supporting both I2C & I3C interfaces.

Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
---
V2 -> V3: Changes since V2:
          - Removed nxp,interrupt-mode and nxp,fault-queue properties from DT binding
          - Updated compatible strings:
            - nxp,p3t1750-iio → nxp,p3t1750dp
            - nxp,p3t1755-iio → nxp,p3t1755dp
V1 -> V2: Changes since V1:
          - Dropped nxp,alert-active-high
          - Fixed YAML formatting, line wrapping, and examples

 .../bindings/iio/temperature/nxp,p3t1755.yaml | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml

diff --git a/Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml b/Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml
new file mode 100644
index 000000000000..16a01fa81251
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/temperature/nxp,p3t1755.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP P3T175xDP Temperature Sensor
+
+maintainers:
+  - Lakshay Piplani <lakshay.piplani@nxp.com>
+
+description: |
+  Datasheet: https://www.nxp.com/docs/en/data-sheet/P3T1755.pdf
+
+  P3T175xDP (P3T1750/P3T1755) is a digital temperature sensor with a range of
+  -40°C to +125°C and a 12-bit resolution. It supports communication over both
+  I2C and I3C interfaces.
+
+  The I2C interface supports up to 32 static addresses and provides an ALERT
+  output to signal when temperature thresholds are crossed.
+
+  The I3C interface supports In-Band interrupts (IBI) in interrupt mode,
+  allowing the device to notify the controller of threshold events without
+  dedicated alert pin.
+
+properties:
+  compatible:
+    enum:
+      - nxp,p3t1750dp
+      - nxp,p3t1755dp
+
+  interrupts:
+    maxItems: 1
+
+  reg:
+    maxItems: 1
+    description: |
+      In I2C mode, the device supports up to 32 static addresses.
+      In I3C mode, the 'reg' property encodes a triplet of
+      <static-address BCR PID> used for device matching.
+      Static address is optional if matching is done via PID.
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        temp-sensor@48 {
+            compatible = "nxp,p3t1755dp";
+            reg = <0x48>;
+            interrupt-parent = <&gpio2>;
+            interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
+        };
+    };
-- 
2.25.1

[PATCH v3 2/2] iio: temperature: Add driver for NXP P3T175x temperature sensor

[Lakshay Piplani]

Add support for the NXP P3T175x (P3T1750/P3T1755) family of temperature
sensor devices. These devices communicates via both I2C or I3C interfaces.

Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
---
V2 -> V3: Changes since V2:
          - Dropped nxp,interrupt-mode and nxp,fault-queue from driver and YAML (not suitable for DT)
          - Removed trigger_one_shot sysfs attribute and its ABI doc
          - Applied IWYU principle: cleaned up unused headers
          - Fixed sampling frequency handling
          - Removed dev_err/dev_dbg statements wherever not necessary
V1 -> V2: Changes since V1:
          - Added endian-safe handling for register read (__be16 conversion)
          - Replaced manual bit masking with FIELD_GET bit extraction
          - Dropped sysfs attributes for fault queue length and thermostat mode (comparator or interrupt)
          - Added ABI doc: Documentation/ABI/testing/sysfs-bus-iio-temperature-p3t1755 describing
            trigger_one_shot attribute
          - Updated Kconfig to allow building both I2C and I3C drivers simultaneously
          - I3C: switched to device_property_* from of_property_*
          - Added devm_add_action_or_reset() for IBI disable/free

 drivers/iio/temperature/Kconfig            |   2 +
 drivers/iio/temperature/p3t/Kconfig        |  28 ++
 drivers/iio/temperature/p3t/Makefile       |   5 +
 drivers/iio/temperature/p3t/p3t1755.h      |  45 +++
 drivers/iio/temperature/p3t/p3t1755_core.c | 362 +++++++++++++++++++++
 drivers/iio/temperature/p3t/p3t1755_i2c.c  |  68 ++++
 drivers/iio/temperature/p3t/p3t1755_i3c.c  | 108 ++++++
 7 files changed, 618 insertions(+)
 create mode 100644 drivers/iio/temperature/p3t/Kconfig
 create mode 100644 drivers/iio/temperature/p3t/Makefile
 create mode 100644 drivers/iio/temperature/p3t/p3t1755.h
 create mode 100644 drivers/iio/temperature/p3t/p3t1755_core.c
 create mode 100644 drivers/iio/temperature/p3t/p3t1755_i2c.c
 create mode 100644 drivers/iio/temperature/p3t/p3t1755_i3c.c

diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
index 1244d8e17d50..d249721c1ea1 100644
--- a/drivers/iio/temperature/Kconfig
+++ b/drivers/iio/temperature/Kconfig
@@ -182,4 +182,6 @@ config MCP9600
 	  This driver can also be built as a module. If so, the module
 	  will be called mcp9600.
 
+source "drivers/iio/temperature/p3t/Kconfig"
+
 endmenu
diff --git a/drivers/iio/temperature/p3t/Kconfig b/drivers/iio/temperature/p3t/Kconfig
new file mode 100644
index 000000000000..0cfd881e065b
--- /dev/null
+++ b/drivers/iio/temperature/p3t/Kconfig
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config IIO_P3T1755
+	tristate
+	depends on (I2C || I3C)
+
+config IIO_P3T1755_I2C
+	tristate "NXP P3T1755 temperature sensor I2C driver"
+	select IIO_P3T1755
+	select REGMAP_I2C
+	help
+	  Say yes here to build support for NXP P3T1755 I2C temperature
+	  sensor.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called p3t1755_i2c
+
+config IIO_P3T1755_I3C
+	tristate "NXP P3T1755 temperature sensor I3C driver"
+	select IIO_P3T1755
+	select REGMAP_I3C
+	depends on I3C
+	help
+	  Say yes here to build support for NXP P3T1755 I3C temperature
+	  sensor.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called p3t1755_i3c
diff --git a/drivers/iio/temperature/p3t/Makefile b/drivers/iio/temperature/p3t/Makefile
new file mode 100644
index 000000000000..7d33b507f1f1
--- /dev/null
+++ b/drivers/iio/temperature/p3t/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_IIO_P3T1755) += p3t1755_core.o
+obj-$(CONFIG_IIO_P3T1755_I2C) += p3t1755_i2c.o
+obj-$(CONFIG_IIO_P3T1755_I3C) += p3t1755_i3c.o
diff --git a/drivers/iio/temperature/p3t/p3t1755.h b/drivers/iio/temperature/p3t/p3t1755.h
new file mode 100644
index 000000000000..1dc0e37322c6
--- /dev/null
+++ b/drivers/iio/temperature/p3t/p3t1755.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * NXP P3T175x Temperature Sensor Driver
+ *
+ * Copyright 2025 NXP
+ */
+#ifndef P3T1755_H
+#define P3T1755_H
+
+#include <linux/bits.h>
+#include <linux/iio/iio.h>
+
+#define P3T1755_REG_TEMP	0x0
+#define P3T1755_REG_CFGR	0x1
+#define P3T1755_REG_LOW_LIM	0x2
+#define P3T1755_REG_HIGH_LIM	0x3
+
+#define P3T1755_SHUTDOWN_BIT	BIT(0)
+#define P3T1755_TM_BIT	BIT(1)
+#define P3T1755_POL_BIT	BIT(2)
+#define P3T1755_ONE_SHOT_BIT	BIT(7)
+
+#define P3T1755_CONVERSION_TIME_BITS	GENMASK(6, 5)
+
+struct p3t1755_info {
+	const char *name;
+	const struct iio_chan_spec *channels;
+	int num_channels;
+};
+
+struct p3t1755_data {
+	struct device *dev;
+	struct regmap *regmap;
+};
+
+extern const struct p3t1755_info p3t1750_channels_info;
+extern const struct p3t1755_info p3t1755_channels_info;
+
+int p3t1755_probe(struct device *dev, const struct p3t1755_info *chip,
+		  struct regmap *regmap, int irq);
+int p3t1755_get_temp_and_limits(struct p3t1755_data *data,
+				int *temp_raw, int *thigh_raw, int *tlow_raw);
+void p3t1755_push_thresh_event(struct iio_dev *indio_dev);
+
+#endif /* P3T1755_H */
diff --git a/drivers/iio/temperature/p3t/p3t1755_core.c b/drivers/iio/temperature/p3t/p3t1755_core.c
new file mode 100644
index 000000000000..61486eb0e265
--- /dev/null
+++ b/drivers/iio/temperature/p3t/p3t1755_core.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * NXP P3T175x Temperature Sensor Driver
+ *
+ * Copyright 2025 NXP
+ */
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+
+#include "p3t1755.h"
+
+static const u32 p3t1755_samp_freqs_uhz[] = {
+	36363636,
+	18181818,
+	9090909,
+	4545454
+};
+
+int p3t1755_get_temp_and_limits(struct p3t1755_data *data,
+				int *temp_raw, int *thigh_raw, int *tlow_raw)
+{
+	__be16 be;
+	int ret;
+	int raw12;
+
+	ret = regmap_bulk_read(data->regmap, P3T1755_REG_TEMP, &be, sizeof(be));
+	if (ret)
+		return ret;
+
+	raw12 = sign_extend32(be16_to_cpu(be) >> 4, 11);
+	*temp_raw = raw12;
+
+	ret = regmap_bulk_read(data->regmap, P3T1755_REG_HIGH_LIM, &be, sizeof(be));
+	if (ret)
+		return ret;
+
+	raw12 = sign_extend32(be16_to_cpu(be) >> 4, 11);
+	*thigh_raw = raw12;
+
+	ret = regmap_bulk_read(data->regmap, P3T1755_REG_LOW_LIM, &be, sizeof(be));
+	if (ret)
+		return ret;
+
+	raw12 = sign_extend32(be16_to_cpu(be) >> 4, 11);
+	*tlow_raw = raw12;
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(p3t1755_get_temp_and_limits, IIO_P3T1755);
+
+void p3t1755_push_thresh_event(struct iio_dev *indio_dev)
+{
+	struct p3t1755_data *data = iio_priv(indio_dev);
+	int ret, temp, thigh, tlow;
+	unsigned int cfgr;
+
+	/*
+	 * Read CFGR register to check device mode and implicitly clear the ALERT latch.
+	 * As per Datasheet: "Any register read will clear the interrupt"
+	 */
+	ret = regmap_read(data->regmap, P3T1755_REG_CFGR, &cfgr);
+	if (ret) {
+		dev_err(data->dev, "Failed to read CFGR register: %d\n", ret);
+		return;
+	}
+
+	if (FIELD_GET(P3T1755_SHUTDOWN_BIT, cfgr)) {
+		dev_dbg(data->dev, "Device is in shutdown mode, skipping event push\n");
+		return;
+	}
+
+	ret = p3t1755_get_temp_and_limits(data, &temp, &thigh, &tlow);
+	if (ret) {
+		dev_err(data->dev, "Failed to get temperature and limits: %d\n", ret);
+		return;
+	}
+
+	if (temp >= thigh || temp <= tlow) {
+		dev_dbg(data->dev, "Threshold event: DIR_EITHER (T=%d, TH=%d, TL=%d)\n",
+			temp, thigh, tlow);
+
+		iio_push_event(indio_dev, IIO_MOD_EVENT_CODE(IIO_TEMP, 0, IIO_NO_MOD,
+							     IIO_EV_TYPE_THRESH, IIO_EV_DIR_EITHER),
+			       iio_get_time_ns(indio_dev));
+	} else {
+		dev_dbg(data->dev, "Temperature within limits: no event triggered (T=%d, TH=%d, TL=%d)\n",
+			temp, thigh, tlow);
+	}
+}
+EXPORT_SYMBOL_NS_GPL(p3t1755_push_thresh_event, IIO_P3T1755);
+
+static int p3t1755_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *channel, int *val,
+			    int *val2, long mask)
+{
+	struct p3t1755_data *data = iio_priv(indio_dev);
+	unsigned int cfgr;
+	__be16 be;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = regmap_bulk_read(data->regmap, P3T1755_REG_TEMP, &be, sizeof(be));
+		if (ret)
+			return ret;
+
+		*val = sign_extend32(be16_to_cpu(be) >> 4, 11);
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SCALE:
+		*val = 625;
+		*val2 = 10000;
+
+		return IIO_VAL_FRACTIONAL;
+
+	case IIO_CHAN_INFO_ENABLE:
+		ret = regmap_read(data->regmap, P3T1755_REG_CFGR, &cfgr);
+		if (ret)
+			return ret;
+
+		*val = !FIELD_GET(P3T1755_SHUTDOWN_BIT, cfgr);
+
+		return IIO_VAL_INT;
+
+	case IIO_CHAN_INFO_SAMP_FREQ: {
+		unsigned int freq_uhz;
+		u8 sel;
+
+		ret = regmap_read(data->regmap, P3T1755_REG_CFGR, &cfgr);
+		if (ret)
+			return ret;
+
+		sel = FIELD_GET(P3T1755_CONVERSION_TIME_BITS, cfgr);
+		if (sel >= ARRAY_SIZE(p3t1755_samp_freqs_uhz))
+			return -EINVAL;
+
+		freq_uhz = p3t1755_samp_freqs_uhz[sel];
+
+		*val = freq_uhz / 1000000;
+		*val2 = freq_uhz % 1000000;
+
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int p3t1755_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan, int val,
+			     int val2, long mask)
+{
+	struct p3t1755_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_ENABLE:
+		ret = regmap_update_bits(data->regmap, P3T1755_REG_CFGR,
+					 P3T1755_SHUTDOWN_BIT,
+					 val == 0 ? P3T1755_SHUTDOWN_BIT : 0);
+		if (ret)
+			return ret;
+
+		return 0;
+	case IIO_CHAN_INFO_SAMP_FREQ: {
+		unsigned int i;
+		u32 regbits;
+		u64 input_uhz;
+
+		input_uhz = (u64)val * 1000000 + val2;
+
+		for (i = 0; i < ARRAY_SIZE(p3t1755_samp_freqs_uhz); i++) {
+			if (p3t1755_samp_freqs_uhz[i] == input_uhz)
+				break;
+		}
+
+		if (i == ARRAY_SIZE(p3t1755_samp_freqs_uhz))
+			return -EINVAL;
+
+		regbits = FIELD_PREP(P3T1755_CONVERSION_TIME_BITS, i);
+
+		return regmap_update_bits(data->regmap, P3T1755_REG_CFGR,
+					  P3T1755_CONVERSION_TIME_BITS,
+					  regbits);
+	}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int p3t1755_read_event_value(struct iio_dev *indio_dev,
+				    const struct iio_chan_spec *chan,
+				    enum iio_event_type type,
+				    enum iio_event_direction dir,
+				    enum iio_event_info info, int *val,
+				    int *val2)
+{
+	struct p3t1755_data *data = iio_priv(indio_dev);
+	unsigned int reg;
+	__be16 be;
+	int ret, raw;
+
+	if (type != IIO_EV_TYPE_THRESH || info != IIO_EV_INFO_VALUE)
+		return -EINVAL;
+
+	reg = (dir == IIO_EV_DIR_RISING) ? P3T1755_REG_HIGH_LIM :
+	       P3T1755_REG_LOW_LIM;
+
+	ret = regmap_bulk_read(data->regmap, reg, &be, sizeof(be));
+	if (ret)
+		return ret;
+
+	raw = sign_extend32(be16_to_cpu(be) >> 4, 11);
+	*val = DIV_ROUND_CLOSEST(raw * 125, 2);
+
+	return IIO_VAL_INT;
+}
+
+static int p3t1755_write_event_value(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan,
+				     enum iio_event_type type,
+				     enum iio_event_direction dir,
+				     enum iio_event_info info,
+				     int val, int val2)
+{
+	struct p3t1755_data *data = iio_priv(indio_dev);
+	unsigned int reg;
+	__be16 be;
+	int raw;
+
+	if (type != IIO_EV_TYPE_THRESH || info != IIO_EV_INFO_VALUE)
+		return -EINVAL;
+
+	if (val2)
+		return -EINVAL;
+
+	reg = (dir == IIO_EV_DIR_RISING) ? P3T1755_REG_HIGH_LIM :
+	       P3T1755_REG_LOW_LIM;
+
+	raw = DIV_ROUND_CLOSEST(val * 2, 125);
+
+	if (raw < -2048 || raw > 2047)
+		return -ERANGE;
+
+	be = cpu_to_be16((u16)(raw << 4));
+
+	return regmap_raw_write(data->regmap, reg, &be, sizeof(be));
+}
+
+static const struct iio_event_spec p3t1755_events[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE),
+	},
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE),
+	},
+};
+
+static const struct iio_chan_spec p3t1755_channels[] = {
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				      BIT(IIO_CHAN_INFO_ENABLE) |
+				      BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+		.event_spec = p3t1755_events,
+		.num_event_specs = ARRAY_SIZE(p3t1755_events),
+	},
+};
+
+const struct p3t1755_info p3t1755_channels_info = {
+	.name = "p3t1755",
+	.channels = p3t1755_channels,
+	.num_channels = ARRAY_SIZE(p3t1755_channels),
+};
+EXPORT_SYMBOL_NS(p3t1755_channels_info, IIO_P3T1755);
+
+const struct p3t1755_info p3t1750_channels_info = {
+	.name = "p3t1750",
+	.channels = p3t1755_channels,
+	.num_channels = ARRAY_SIZE(p3t1755_channels),
+};
+EXPORT_SYMBOL_NS(p3t1750_channels_info, IIO_P3T1755);
+
+static const struct iio_info p3t1755_info = {
+	.read_raw = p3t1755_read_raw,
+	.write_raw = p3t1755_write_raw,
+	.read_event_value = p3t1755_read_event_value,
+	.write_event_value = p3t1755_write_event_value,
+};
+
+static irqreturn_t p3t1755_irq_handler(int irq, void *dev_id)
+{
+	struct iio_dev *indio_dev = dev_id;
+
+	dev_dbg(&indio_dev->dev, "IRQ triggered, processing threshold event\n");
+
+	p3t1755_push_thresh_event(indio_dev);
+
+	return IRQ_HANDLED;
+}
+
+int p3t1755_probe(struct device *dev, const struct p3t1755_info *chip,
+		  struct regmap *regmap, int irq)
+{
+	struct p3t1755_data *data;
+	struct iio_dev *iio_dev;
+	int ret;
+
+	iio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!iio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(iio_dev);
+	data->dev = dev;
+	data->regmap = regmap;
+
+	iio_dev->name = chip->name;
+	iio_dev->modes = INDIO_DIRECT_MODE;
+	iio_dev->info = &p3t1755_info;
+	iio_dev->channels = chip->channels;
+	iio_dev->num_channels = chip->num_channels;
+
+	ret = regmap_update_bits(data->regmap, P3T1755_REG_CFGR,
+				 P3T1755_TM_BIT, P3T1755_TM_BIT);
+	if (ret)
+		return dev_err_probe(data->dev, ret, "Failed to update TM bit\n");
+
+	ret = devm_iio_device_register(dev, iio_dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Temperature sensor failed to register\n");
+
+	if (irq > 0) {
+		ret = devm_request_threaded_irq(dev, irq, NULL,
+						p3t1755_irq_handler, IRQF_ONESHOT,
+						"p3t175xdp", iio_dev);
+		if (ret)
+			dev_err_probe(dev, ret, "Failed to request IRQ: %d\n", ret);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_NS(p3t1755_probe, IIO_P3T1755);
+
+MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
+MODULE_DESCRIPTION("NXP P3T175x Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/temperature/p3t/p3t1755_i2c.c b/drivers/iio/temperature/p3t/p3t1755_i2c.c
new file mode 100644
index 000000000000..f5d7799f091c
--- /dev/null
+++ b/drivers/iio/temperature/p3t/p3t1755_i2c.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * NXP P3T175x Temperature Sensor Driver
+ *
+ * Copyright 2025 NXP
+ */
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "p3t1755.h"
+
+static const struct regmap_config p3t1755_i2c_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static const struct of_device_id p3t1755_i2c_of_match[] = {
+	{ .compatible = "nxp,p3t1750dp", .data = &p3t1750_channels_info },
+	{ .compatible = "nxp,p3t1755dp", .data = &p3t1755_channels_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, p3t1755_i2c_of_match);
+
+static const struct i2c_device_id p3t1755_i2c_id_table[] = {
+	{ "p3t1750", (kernel_ulong_t)&p3t1750_channels_info },
+	{ "p3t1755", (kernel_ulong_t)&p3t1755_channels_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, p3t1755_i2c_id_table);
+
+static int p3t1755_i2c_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	const struct p3t1755_info *chip;
+	struct regmap *regmap;
+	int ret;
+
+	regmap = devm_regmap_init_i2c(client, &p3t1755_i2c_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap),
+				     "regmap init failed\n");
+
+	chip = i2c_get_match_data(client);
+
+	ret = p3t1755_probe(dev, chip, regmap, client->irq);
+
+	if (ret)
+		return dev_err_probe(dev, ret, "p3t175x probe failed: %d\n", ret);
+
+	return 0;
+}
+
+static struct i2c_driver p3t1755_driver = {
+	.driver = {
+		.name = "p3t175x_i2c",
+		.of_match_table = p3t1755_i2c_of_match,
+	},
+	.probe = p3t1755_i2c_probe,
+	.id_table = p3t1755_i2c_id_table,
+};
+module_i2c_driver(p3t1755_driver);
+
+MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
+MODULE_DESCRIPTION("NXP P3T175x I2C Driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_P3T1755);
diff --git a/drivers/iio/temperature/p3t/p3t1755_i3c.c b/drivers/iio/temperature/p3t/p3t1755_i3c.c
new file mode 100644
index 000000000000..df031280e08d
--- /dev/null
+++ b/drivers/iio/temperature/p3t/p3t1755_i3c.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NXP P3T175x Temperature Sensor Driver
+ *
+ * Copyright 2025 NXP
+ */
+#include <linux/i3c/device.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/events.h>
+
+#include "p3t1755.h"
+
+static const struct regmap_config p3t1755_i3c_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static void p3t1755_ibi_handler(struct i3c_device *dev,
+				const struct i3c_ibi_payload *payload)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(&dev->dev);
+
+	p3t1755_push_thresh_event(indio_dev);
+}
+
+/*
+ * Both P3T1755 and P3T1750 share the same I3C PID (0x011B:0x152A),
+ * making runtime differentiation impossible, so using "p3t1755" as
+ * name in sysfs and IIO for I3C based instances.
+ */
+static const struct i3c_device_id p3t1755_i3c_ids[] = {
+	I3C_DEVICE(0x011B, 0x152A, &p3t1755_channels_info),
+	{ }
+};
+MODULE_DEVICE_TABLE(i3c, p3t1755_i3c_ids);
+
+static void p3t1755_disable_ibi(void *data)
+{
+	i3c_device_disable_ibi((struct i3c_device *)data);
+}
+
+static void p3t1755_free_ibi(void *data)
+{
+	i3c_device_free_ibi((struct i3c_device *)data);
+}
+
+static int p3t1755_i3c_probe(struct i3c_device *i3cdev)
+{
+	const struct i3c_device_id *id = i3c_device_match_id(i3cdev, p3t1755_i3c_ids);
+	const struct p3t1755_info *chip;
+	struct device *dev = &i3cdev->dev;
+	struct i3c_ibi_setup ibi_setup;
+	struct regmap *regmap;
+	int ret;
+
+	chip = id ? id->data : NULL;
+
+	regmap = devm_regmap_init_i3c(i3cdev, &p3t1755_i3c_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(&i3cdev->dev, PTR_ERR(regmap),
+				     "Failed to register I3C regmap %ld\n", PTR_ERR(regmap));
+
+	ret = p3t1755_probe(dev, chip, regmap, 0);
+	if (ret)
+		return dev_err_probe(dev, ret, "p3t175x probe failed: %d\n", ret);
+
+	ibi_setup = (struct i3c_ibi_setup) {
+		.handler = p3t1755_ibi_handler,
+		.num_slots = 4,
+		.max_payload_len = 0,
+	};
+
+	ret = i3c_device_request_ibi(i3cdev, &ibi_setup);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to request IBI\n");
+
+	ret = devm_add_action_or_reset(dev, p3t1755_free_ibi, i3cdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register IBI free action\n");
+
+	ret = i3c_device_enable_ibi(i3cdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to enable IBI\n");
+
+	ret = devm_add_action_or_reset(dev, p3t1755_disable_ibi, i3cdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to register IBI disable action\n");
+
+	return 0;
+}
+
+static struct i3c_driver p3t1755_driver = {
+	.driver = {
+		.name = "p3t175x_i3c",
+	},
+	.probe = p3t1755_i3c_probe,
+	.id_table = p3t1755_i3c_ids,
+};
+module_i3c_driver(p3t1755_driver);
+
+MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
+MODULE_DESCRIPTION("NXP P3T175x I3C Driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(IIO_P3T1755);
-- 
2.25.1

Re: [PATCH v3 1/2] dt-bindings: iio: temperature: Add NXP P3T175x support

[Conor Dooley]

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On Mon, Sep 29, 2025 at 03:15:42PM +0530, Lakshay Piplani wrote:
> Add bindings for the NXP P3T175x (P3T1750/P3T1755) temperature
> sensor, supporting both I2C & I3C interfaces.

Can you please mention here what the difference between devices is?

> 
> Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
> ---
> V2 -> V3: Changes since V2:
>           - Removed nxp,interrupt-mode and nxp,fault-queue properties from DT binding
>           - Updated compatible strings:
>             - nxp,p3t1750-iio → nxp,p3t1750dp
>             - nxp,p3t1755-iio → nxp,p3t1755dp
> V1 -> V2: Changes since V1:
>           - Dropped nxp,alert-active-high
>           - Fixed YAML formatting, line wrapping, and examples
> 
>  .../bindings/iio/temperature/nxp,p3t1755.yaml | 62 +++++++++++++++++++
>  1 file changed, 62 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml b/Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml
> new file mode 100644
> index 000000000000..16a01fa81251
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml
> @@ -0,0 +1,62 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/temperature/nxp,p3t1755.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: NXP P3T175xDP Temperature Sensor
> +
> +maintainers:
> +  - Lakshay Piplani <lakshay.piplani@nxp.com>
> +
> +description: |
> +  Datasheet: https://www.nxp.com/docs/en/data-sheet/P3T1755.pdf
> +
> +  P3T175xDP (P3T1750/P3T1755) is a digital temperature sensor with a range of
> +  -40°C to +125°C and a 12-bit resolution. It supports communication over both
> +  I2C and I3C interfaces.
> +
> +  The I2C interface supports up to 32 static addresses and provides an ALERT
> +  output to signal when temperature thresholds are crossed.
> +
> +  The I3C interface supports In-Band interrupts (IBI) in interrupt mode,
> +  allowing the device to notify the controller of threshold events without
> +  dedicated alert pin.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - nxp,p3t1750dp
> +      - nxp,p3t1755dp
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  reg:
> +    maxItems: 1
> +    description: |
> +      In I2C mode, the device supports up to 32 static addresses.
> +      In I3C mode, the 'reg' property encodes a triplet of
> +      <static-address BCR PID> used for device matching.
> +      Static address is optional if matching is done via PID.
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        temp-sensor@48 {
> +            compatible = "nxp,p3t1755dp";
> +            reg = <0x48>;
> +            interrupt-parent = <&gpio2>;
> +            interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
> +        };
> +    };
> -- 
> 2.25.1
> 

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Re: [PATCH v3 2/2] iio: temperature: Add driver for NXP P3T175x temperature sensor

[Jonathan Cameron]

On Mon, 29 Sep 2025 15:15:43 +0530
Lakshay Piplani <lakshay.piplani@nxp.com> wrote:

> Add support for the NXP P3T175x (P3T1750/P3T1755) family of temperature
> sensor devices. These devices communicates via both I2C or I3C interfaces.
> 
> Signed-off-by: Lakshay Piplani <lakshay.piplani@nxp.com>
Hi Lakshay,

Please add a cover letter. I would have replied to that if there was one.

After some recent feedback on hwmon vs IIO sensors and the fact we do
indeed seem to be slowly drifting wrt to the boundary for what I let into IIO
I'm asking people to +CC the hwmon maintainers and provide an explanation of why
they think a particular device should be supported with an IIO driver rather than
a hwmon one. 

So +CC Guenter and Jean,

Sorry I didn't raise this earlier. I've clearly not been paying quite enough attention
to this.  Had my head down in code reviews rather than looking at the bigger picture.

I'm not immediately spotting characteristics that would clearly justify this being
in IIO.

Review comments inline.

Thanks,

Jonathan


> ---
> V2 -> V3: Changes since V2:
>           - Dropped nxp,interrupt-mode and nxp,fault-queue from driver and YAML (not suitable for DT)
>           - Removed trigger_one_shot sysfs attribute and its ABI doc
>           - Applied IWYU principle: cleaned up unused headers
>           - Fixed sampling frequency handling
>           - Removed dev_err/dev_dbg statements wherever not necessary
> V1 -> V2: Changes since V1:
>           - Added endian-safe handling for register read (__be16 conversion)
>           - Replaced manual bit masking with FIELD_GET bit extraction
>           - Dropped sysfs attributes for fault queue length and thermostat mode (comparator or interrupt)
>           - Added ABI doc: Documentation/ABI/testing/sysfs-bus-iio-temperature-p3t1755 describing
>             trigger_one_shot attribute
>           - Updated Kconfig to allow building both I2C and I3C drivers simultaneously
>           - I3C: switched to device_property_* from of_property_*
>           - Added devm_add_action_or_reset() for IBI disable/free
> 
>  drivers/iio/temperature/Kconfig            |   2 +
>  drivers/iio/temperature/p3t/Kconfig        |  28 ++
>  drivers/iio/temperature/p3t/Makefile       |   5 +
>  drivers/iio/temperature/p3t/p3t1755.h      |  45 +++
>  drivers/iio/temperature/p3t/p3t1755_core.c | 362 +++++++++++++++++++++
>  drivers/iio/temperature/p3t/p3t1755_i2c.c  |  68 ++++
>  drivers/iio/temperature/p3t/p3t1755_i3c.c  | 108 ++++++
>  7 files changed, 618 insertions(+)
>  create mode 100644 drivers/iio/temperature/p3t/Kconfig
>  create mode 100644 drivers/iio/temperature/p3t/Makefile
>  create mode 100644 drivers/iio/temperature/p3t/p3t1755.h
>  create mode 100644 drivers/iio/temperature/p3t/p3t1755_core.c
>  create mode 100644 drivers/iio/temperature/p3t/p3t1755_i2c.c
>  create mode 100644 drivers/iio/temperature/p3t/p3t1755_i3c.c
> 

> diff --git a/drivers/iio/temperature/p3t/p3t1755.h b/drivers/iio/temperature/p3t/p3t1755.h
> new file mode 100644
> index 000000000000..1dc0e37322c6
> --- /dev/null
> +++ b/drivers/iio/temperature/p3t/p3t1755.h

> diff --git a/drivers/iio/temperature/p3t/p3t1755_core.c b/drivers/iio/temperature/p3t/p3t1755_core.c
> new file mode 100644
> index 000000000000..61486eb0e265
> --- /dev/null
> +++ b/drivers/iio/temperature/p3t/p3t1755_core.c


> +
> +static int p3t1755_read_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *channel, int *val,
> +			    int *val2, long mask)
> +{
> +	struct p3t1755_data *data = iio_priv(indio_dev);
> +	unsigned int cfgr;
> +	__be16 be;
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		ret = regmap_bulk_read(data->regmap, P3T1755_REG_TEMP, &be, sizeof(be));
> +		if (ret)
> +			return ret;
> +
> +		*val = sign_extend32(be16_to_cpu(be) >> 4, 11);
> +
> +		return IIO_VAL_INT;
> +
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = 625;
> +		*val2 = 10000;
> +
> +		return IIO_VAL_FRACTIONAL;
> +
> +	case IIO_CHAN_INFO_ENABLE:
> +		ret = regmap_read(data->regmap, P3T1755_REG_CFGR, &cfgr);
> +		if (ret)
> +			return ret;
> +
> +		*val = !FIELD_GET(P3T1755_SHUTDOWN_BIT, cfgr);
> +
> +		return IIO_VAL_INT;
> +
> +	case IIO_CHAN_INFO_SAMP_FREQ: {
> +		unsigned int freq_uhz;
> +		u8 sel;
> +
> +		ret = regmap_read(data->regmap, P3T1755_REG_CFGR, &cfgr);
> +		if (ret)
> +			return ret;
> +
> +		sel = FIELD_GET(P3T1755_CONVERSION_TIME_BITS, cfgr);
> +		if (sel >= ARRAY_SIZE(p3t1755_samp_freqs_uhz))
> +			return -EINVAL;
> +
> +		freq_uhz = p3t1755_samp_freqs_uhz[sel];
> +
> +		*val = freq_uhz / 1000000;
> +		*val2 = freq_uhz % 1000000;

MICRO (see below).

> +
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	}
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int p3t1755_write_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan, int val,
> +			     int val2, long mask)
> +{
> +	struct p3t1755_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_ENABLE:
> +		ret = regmap_update_bits(data->regmap, P3T1755_REG_CFGR,
> +					 P3T1755_SHUTDOWN_BIT,
> +					 val == 0 ? P3T1755_SHUTDOWN_BIT : 0);
> +		if (ret)
> +			return ret;
> +
> +		return 0;
> +	case IIO_CHAN_INFO_SAMP_FREQ: {
> +		unsigned int i;
> +		u32 regbits;
> +		u64 input_uhz;
> +
> +		input_uhz = (u64)val * 1000000 + val2;

MICRO perhaps as that's on the border of how many zeros are easy to count.

> +
> +		for (i = 0; i < ARRAY_SIZE(p3t1755_samp_freqs_uhz); i++) {
> +			if (p3t1755_samp_freqs_uhz[i] == input_uhz)
> +				break;
> +		}
> +
> +		if (i == ARRAY_SIZE(p3t1755_samp_freqs_uhz))
> +			return -EINVAL;
> +
> +		regbits = FIELD_PREP(P3T1755_CONVERSION_TIME_BITS, i);
> +
> +		return regmap_update_bits(data->regmap, P3T1755_REG_CFGR,
> +					  P3T1755_CONVERSION_TIME_BITS,
> +					  regbits);
> +	}
> +	default:
> +		return -EINVAL;
> +	}
> +}

> +
> +static int p3t1755_write_event_value(struct iio_dev *indio_dev,
> +				     const struct iio_chan_spec *chan,
> +				     enum iio_event_type type,
> +				     enum iio_event_direction dir,
> +				     enum iio_event_info info,
> +				     int val, int val2)
> +{
> +	struct p3t1755_data *data = iio_priv(indio_dev);
> +	unsigned int reg;
> +	__be16 be;
> +	int raw;
> +
> +	if (type != IIO_EV_TYPE_THRESH || info != IIO_EV_INFO_VALUE)
> +		return -EINVAL;
> +
> +	if (val2)
> +		return -EINVAL;
> +
> +	reg = (dir == IIO_EV_DIR_RISING) ? P3T1755_REG_HIGH_LIM :
> +	       P3T1755_REG_LOW_LIM;
> +
> +	raw = DIV_ROUND_CLOSEST(val * 2, 125);
> +
> +	if (raw < -2048 || raw > 2047)
> +		return -ERANGE;
> +
> +	be = cpu_to_be16((u16)(raw << 4));
> +
> +	return regmap_raw_write(data->regmap, reg, &be, sizeof(be));

Why is raw write appropriate here rather than bulk_write ?
Perhaps a comment would be a good idea for anyone wondering in future.

> +}

> +
> +MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
> +MODULE_DESCRIPTION("NXP P3T175x Driver");

As below wrt to wild cards.

> +MODULE_LICENSE("GPL");
> diff --git a/drivers/iio/temperature/p3t/p3t1755_i2c.c b/drivers/iio/temperature/p3t/p3t1755_i2c.c
> new file mode 100644
> index 000000000000..f5d7799f091c
> --- /dev/null
> +++ b/drivers/iio/temperature/p3t/p3t1755_i2c.c

> +static int p3t1755_i2c_probe(struct i2c_client *client)
> +{
> +	struct device *dev = &client->dev;
> +	const struct p3t1755_info *chip;
> +	struct regmap *regmap;
> +	int ret;
> +
> +	regmap = devm_regmap_init_i2c(client, &p3t1755_i2c_regmap_config);
> +	if (IS_ERR(regmap))
> +		return dev_err_probe(dev, PTR_ERR(regmap),
> +				     "regmap init failed\n");
> +
> +	chip = i2c_get_match_data(client);
> +
> +	ret = p3t1755_probe(dev, chip, regmap, client->irq);
> +
Drop this blank line. We want the error handling closely coupled with the call.

> +	if (ret)
> +		return dev_err_probe(dev, ret, "p3t175x probe failed: %d\n", ret);
> +
> +	return 0;
> +}
> +
> +static struct i2c_driver p3t1755_driver = {
> +	.driver = {
> +		.name = "p3t175x_i2c",

Pick a part number rather than using a wild card. Wildcards often down withstand
the desire of marketing departments to fill in the holes.

> +		.of_match_table = p3t1755_i2c_of_match,
> +	},
> +	.probe = p3t1755_i2c_probe,
> +	.id_table = p3t1755_i2c_id_table,
> +};
> +module_i2c_driver(p3t1755_driver);
> +
> +MODULE_AUTHOR("Lakshay Piplani <lakshay.piplani@nxp.com>");
> +MODULE_DESCRIPTION("NXP P3T175x I2C Driver");

I'd use a part number rather than wild card here as well.

> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS(IIO_P3T1755);
> diff --git a/drivers/iio/temperature/p3t/p3t1755_i3c.c b/drivers/iio/temperature/p3t/p3t1755_i3c.c
> new file mode 100644
> index 000000000000..df031280e08d
> --- /dev/null
> +++ b/drivers/iio/temperature/p3t/p3t1755_i3c.c
> @@ -0,0 +1,108 @@

...

> +
> +static void p3t1755_disable_ibi(void *data)
> +{
> +	i3c_device_disable_ibi((struct i3c_device *)data);

As below - unnecessary cast.

> +}
> +
> +static void p3t1755_free_ibi(void *data)
> +{
> +	i3c_device_free_ibi((struct i3c_device *)data);

That cast isn't needed.  Casting from void * to any other pointer is implicitly allowed
by the c spec.  So just pass data directly.

> +}
> +
> +static int p3t1755_i3c_probe(struct i3c_device *i3cdev)
> +{
> +	const struct i3c_device_id *id = i3c_device_match_id(i3cdev, p3t1755_i3c_ids);
> +	const struct p3t1755_info *chip;
> +	struct device *dev = &i3cdev->dev;
> +	struct i3c_ibi_setup ibi_setup;
> +	struct regmap *regmap;
> +	int ret;
> +
> +	chip = id ? id->data : NULL;
> +
> +	regmap = devm_regmap_init_i3c(i3cdev, &p3t1755_i3c_regmap_config);
> +	if (IS_ERR(regmap))
> +		return dev_err_probe(&i3cdev->dev, PTR_ERR(regmap),
> +				     "Failed to register I3C regmap %ld\n", PTR_ERR(regmap));
> +
> +	ret = p3t1755_probe(dev, chip, regmap, 0);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "p3t175x probe failed: %d\n", ret);
> +
> +	ibi_setup = (struct i3c_ibi_setup) {
> +		.handler = p3t1755_ibi_handler,
> +		.num_slots = 4,
> +		.max_payload_len = 0,
> +	};
> +
> +	ret = i3c_device_request_ibi(i3cdev, &ibi_setup);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to request IBI\n");
> +
> +	ret = devm_add_action_or_reset(dev, p3t1755_free_ibi, i3cdev);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to register IBI free action\n");

As below.

> +
> +	ret = i3c_device_enable_ibi(i3cdev);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to enable IBI\n");
> +
> +	ret = devm_add_action_or_reset(dev, p3t1755_disable_ibi, i3cdev);
> +	if (ret)

Don't bother with error prints for devm_add_action_or_reset().
The only failure path returns -ENOMEM which doesn't result in a print in
dev_err_probe() because the expectation is that it is an unlikely condition
which results in plenty of prints anyway.
So simple
		return ret;
appropriate for these calls.


> +		return dev_err_probe(dev, ret, "Failed to register IBI disable action\n");
> +
> +	return 0;
> +}