Message-ID: <6a7a2721-063d-490a-8fd9-bec101531027@kernel.org>
Date: Sun, 31 Aug 2025 18:47:45 +0200
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Lakshay Piplani <lakshay.piplani@....com>, linux-kernel@...r.kernel.org,
 linux-iio@...r.kernel.org, jic23@...nel.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
Cc: 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 27/08/2025 12:31, Lakshay Piplani 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`.

Where was v1? Why aren't you using b4 for all this?

>  - 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.

Huh? Why?

> 
>  .../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
> +  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

Drop iio

> +
> +  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.
> +
> +  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.
> +
> +  assigned-address:
> +    true

Drop and instead we need to define i3c-peripheral-properties, just like
spi has. Then you reference here that file.

> +
> +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,p3t1755-iio";
> +            reg = <0x48>;
> +            nxp,interrupt-mode;
> +            nxp,fault-queue = <6>;
> +            interrupt-parent = <&gpio2>;
> +            interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
> +        };
> +    };
> +
> +  - |
> +    i3c {
> +      #address-cells = <3>;
> +      #size-cells = <0>;
> +      temp-sensor@48,236152a00 {
> +        reg = <0x48 0x236 0x152a00>;
> +        assigned-address = <0x50>;

This example is pretty incomplete.

> +      };
> +    };


Best regards,
Krzysztof

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