Message-ID: <c9db83e8-f87d-b94d-0c23-8114adb312e1@linaro.org>
Date:   Sun, 12 Mar 2023 21:47:47 +0100
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Subject: Re: [PATCH 1/5] dt-bindings: input: touchscreen: add bindings for
 focaltech,fts
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To:     Joel Selvaraj <joelselvaraj.oss@gmail.com>,
        Caleb Connolly <caleb@connolly.tech>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Henrik Rydberg <rydberg@bitmath.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Robert Jarzmik <robert.jarzmik@free.fr>,
        Jeff LaBundy <jeff@labundy.com>,
        Neil Armstrong <neil.armstrong@linaro.org>,
        Markuss Broks <markuss.broks@gmail.com>,
        Jean Delvare <jdelvare@suse.de>,
        Max Krummenacher <max.krummenacher@toradex.com>,
        Job Noorman <job@noorman.info>,
        Alistair Francis <alistair@alistair23.me>,
        Chris Morgan <macromorgan@hotmail.com>
Cc:     linux-input@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org
References: <20230312093249.1846993-1-joelselvaraj.oss@gmail.com>
 <20230312093249.1846993-2-joelselvaraj.oss@gmail.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20230312093249.1846993-2-joelselvaraj.oss@gmail.com>
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Precedence: bulk

On 12/03/2023 10:32, Joel Selvaraj wrote:
> Add devicetree bindings for the Focaltech FTS touchscreen drivers.
> 
> Signed-off-by: Joel Selvaraj <joelselvaraj.oss@gmail.com>
> Signed-off-by: Caleb Connolly <caleb@connolly.tech>
> ---
>  .../input/touchscreen/focaltech,fts.yaml      | 81 +++++++++++++++++++
>  1 file changed, 81 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/input/touchscreen/focaltech,fts.yaml
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/focaltech,fts.yaml b/Documentation/devicetree/bindings/input/touchscreen/focaltech,fts.yaml
> new file mode 100644
> index 000000000000..07fe595cc9ed
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/input/touchscreen/focaltech,fts.yaml

I have doubts you will cover here all possible FTS controllers, so
filename should be more specific, e.g. choose the oldest device compatible.

> @@ -0,0 +1,81 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/input/touchscreen/focaltech,fts.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Focaltech FTS I2C Touchscreen Controller
> +
> +maintainers:
> +  - Joel Selvaraj <joelselvaraj.oss@gmail.com>
> +  - Caleb Connolly <caleb@connolly.tech>
> +
> +allOf:
> +  - $ref: touchscreen.yaml#
> +
> +properties:
> +  compatible:
> +    enum:
> +      - focaltech,fts5452
> +      - focaltech,fts8719

Missing blank line

> +  reg:
> +    const: 0x38
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  reset-gpios:
> +    maxItems: 1
> +
> +  avdd-supply:
> +    description: a phandle for the regulator supplying analog power (2.6V to 3.3V).

Drop "a phandle for the"

> +
> +  vddio-supply:
> +    description: a phandle for the regulator supplying IO power (1.8V).

Ditto

> +
> +  focaltech,max-touch-number:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: max number of fingers supported

Why this is not implied from compatible? IOW, why this differs between
boards?

If this property stays, then anyway "focaltech,max-touch", not number.
There is no such unit suffix as number.

> +    minimum: 2
> +    maximum: 10
> +
> +  touchscreen-size-x: true
> +  touchscreen-size-y: true

Drop these two

> +
> +additionalProperties: false

and then use unevaluatedProperties: false
so all properties from common schema apply. Unless these are not really
valid for the *device*?

> +
> +required:
> +  - compatible
> +  - reg
> +  - reset-gpios
> +  - focaltech,max-touch-number
> +  - touchscreen-size-x
> +  - touchscreen-size-y
> +
> +examples:
> +  - |
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/gpio/gpio.h>
> +    &i2c5 {

i2c

> +      status="okay";

Drop status

Anyway this should pop warnings... Please run `make dt_binding_check`
(see Documentation/devicetree/bindings/writing-schema.rst for instructions).

> +
> +      touchscreen: focaltech@38 {

Node names should be generic.
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

Also, drop label touchscreen.

> +        compatible = "focaltech,fts8719";
> +        reg = <0x38>;
> +        interrupt-parent = <&tlmm>;
> +        interrupts = <31 IRQ_TYPE_EDGE_RISING>;
> +


Best regards,
Krzysztof