Message-ID: <20250831170127.3c7d9bf7@jic23-huawei>
Date: Sun, 31 Aug 2025 17:01:27 +0100
From: Jonathan Cameron <jic23@...nel.org>
To: Lakshay Piplani <lakshay.piplani@....com>
Cc: linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org,
 dlechner@...libre.com, nuno.sa@...log.com, andy@...nel.org,
 marcelo.schmitt1@...il.com, gregkh@...uxfoundation.org,
 viro@...iv.linux.org.uk, peterz@...radead.org, jstephan@...libre.com,
 robh@...nel.org, krzk+dt@...nel.org, conor+dt@...nel.org,
 devicetree@...r.kernel.org, ilpo.jarvinen@...ux.intel.com,
 jonathan.cameron@...wei.com, akpm@...ux-foundation.org, chao@...nel.org,
 jaegeuk@...nel.org, vikash.bansal@....com, priyanka.jain@....com,
 shashank.rebbapragada@....com, Frank.Li@....com
Subject: Re: [PATCH v2 1/2] dt-bindings: iio: temperature: Add NXP P3T175x
 support

On Wed, 27 Aug 2025 16:01:04 +0530
Lakshay Piplani <lakshay.piplani@....com> wrote:

> Add bindings for the NXP P3T175x (P3T1750/P3T1755) temperature
> sensor, supporting both I2C & I3C interfaces.
> 
> Signed-off-by: Lakshay Piplani <lakshay.piplani@....com>
> ---
> Changes in v2 (addressed review comments from Krzysztof Kozlowski):
>  - Dropped nxp,alert-active-high: unnecessary as polarity handling is implicit in driver.
>  - Retained nxp,interrupt-mode: required to program TM(thermostat mode) bit; enables interrupt
>    (latched) mode. If not present in DT entry comparator mode is set as default.
>  - Retained nxp,fault-queue: This needs to be configured during device initialization.
>    This property configures the hardware fault queue length. Defines how many consecutive faults
>    are required before ALERT/IBI is asserted, preventing false triggers in noisy environments.
>  - The `reg` property remains required to satisfy `dt_binding_check`.
>  - Fixed YAML formatting, line wrapping, and examples.
>  - Changed compatibles from nxp,p3t1755 to nxp,p3t1755-iio and nxp,p3t1750 to nxp,p3t1750-iio
>    as reported by kernel test robot.
> 
>  .../bindings/iio/temperature/nxp,p3t1755.yaml | 97 +++++++++++++++++++
>  1 file changed, 97 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..4eb6fc5cb247
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/temperature/nxp,p3t1755.yaml
> @@ -0,0 +1,97 @@
> +# 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 P3T175x Temperature Sensor
> +
> +maintainers:
> +  - Lakshay Piplani <lakshay.piplani@....com>
> +
> +description: |
> +  Datasheet: https://www.nxp.com/docs/en/data-sheet/P3T1755.pdf
> +
> +  P3T175x (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

Wrap consistently to 80 chars

> +  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.
> +
> +  The device supports configurable thermostat modes (interrupt or comparator),
> +  fault queue length etc.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - nxp,p3t1750-iio
> +      - nxp,p3t1755-iio

Wouldn't expect an 'iio' bit in a compatible. It's not about what driver
is binding, it's about what the device is.

> +
> +  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.
> +
> +  nxp,interrupt-mode:
> +    type: boolean
> +    description: |
> +      Enables interrupt mode (TM = 1), where alerts are latched until
> +      cleared by a register read.
> +      Required for IBI support over I3C. On I2C, both interrupt and
> +      comparator mode support events.

What David said wrt to this. If it is discoverable from the bus type
doesn't need a property.

> +
> +  nxp,fault-queue:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    enum: [1, 2, 4, 6]
> +    description: |
> +      Number of consecutive temperature limit
> +      violations required before an alert is triggered.
> +      valid values:- 1, 2, 4 or 6.
> +      If unspecified, hardware default (2) is used.

This is the userspace period control. Don't have it in DT
as nothing much to do with wiring.

> +
> +  assigned-address:
> +    true

Is there not a top level i3c file that we can $ref like tend to do for spi-peripheral-props.yaml?
Seems not unfortunately but we do need some sort of reference for this.

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