linux-kernel - Re: [PATCH v4 3/3] dt-bindings: gpio: add NPCM sgpio driver bindings

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Message-ID: <d56c24c2-a017-8468-0b3a-bd93d6024c69@linaro.org>
Date:   Tue, 10 Jan 2023 11:35:49 +0100
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Jim Liu <jim.t90615@...il.com>, JJLIU0@...oton.com,
        KWLIU@...oton.com, linus.walleij@...aro.org, brgl@...ev.pl,
        robh+dt@...nel.org, krzysztof.kozlowski+dt@...aro.org
Cc:     linux-gpio@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, openbmc@...ts.ozlabs.org
Subject: Re: [PATCH v4 3/3] dt-bindings: gpio: add NPCM sgpio driver bindings

On 10/01/2023 09:32, Jim Liu wrote:
> Add dt-bindings document for the Nuvoton NPCM7xx and NPCM8xx sgpio driver
> 
> Signed-off-by: Jim Liu <jim.t90615@...il.com>
> ---
> Changes for v4:
>    - modify in/out property
>    - modify bus-frequency property
> Changes for v3:
>    - modify description
>    - modify in/out property name
> Changes for v2:
>    - modify description
> ---
>  .../bindings/gpio/nuvoton,sgpio.yaml          | 92 +++++++++++++++++++
>  1 file changed, 92 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/nuvoton,sgpio.yaml
> 
> diff --git a/Documentation/devicetree/bindings/gpio/nuvoton,sgpio.yaml b/Documentation/devicetree/bindings/gpio/nuvoton,sgpio.yaml
> new file mode 100644
> index 000000000000..3c01ce61f8d9
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/nuvoton,sgpio.yaml
> @@ -0,0 +1,92 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpio/nuvoton,sgpio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Nuvoton SGPIO controller
> +
> +maintainers:
> +  - Jim LIU <JJLIU0@...oton.com>
> +
> +description:
> +  This SGPIO controller is for NUVOTON NPCM7xx and NPCM8xx SoC.
> +  Nuvoton NPCM7xx SGPIO module is combine serial to parallel IC (HC595)
> +  and parallel to serial IC (HC165), and use APB3 clock to control it.
> +  This interface has 4 pins  (D_out , D_in, S_CLK, LDSH).
> +  NPCM7xx/NPCM8xx have two sgpio module each module can support up
> +  to 64 output pins,and up to 64 input pin, the pin is only for gpi or gpo.
> +  GPIO pins have sequential, First half is gpo and second half is gpi.
> +  GPIO pins can be programmed to support the following options
> +  - Support interrupt option for each input port and various interrupt
> +    sensitivity option (level-high, level-low, edge-high, edge-low)
> +  - ngpios is number of nuvoton,input-ngpios GPIO lines and nuvoton,output-ngpios GPIO lines.
> +    nuvoton,input-ngpios GPIO lines is only for gpi.
> +    nuvoton,output-ngpios GPIO lines is only for gpo.
> +
> +properties:
> +  compatible:
> +    enum:
> +      - nuvoton,npcm750-sgpio
> +      - nuvoton,npcm845-sgpio
> +
> +  reg:
> +    maxItems: 1
> +
> +  gpio-controller: true
> +
> +  '#gpio-cells':
> +    const: 2
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  nuvoton,input-ngpios:
> +    description: The numbers of GPIO's exposed.
> +      GPIO lines is only for gpi.
> +    minimum: 0
> +    maximum: 64
> +
> +  nuvoton,output-ngpios:
> +    description: The numbers of GPIO's exposed.
> +      GPIO lines is only for gpo.
> +    minimum: 0
> +    maximum: 64
> +
> +  bus-frequency:
> +    description: Directly connected to APB bus and 
> +      its shift clock is from APB bus clock divided by a programmable value.

The bus frequency is derived from input clocks, isn't it? We already
questioned this property and this does not help justify it existence.
Drop it.

> +    default: 8000000
> +
> +required:
> +  - compatible
> +  - reg
> +  - gpio-controller
> +  - '#gpio-cells'
> +  - interrupts
> +  - nuvoton,input-ngpios
> +  - nuvoton,output-ngpios
> +  - clocks
> +  - bus-frequency
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    #include <dt-bindings/clock/nuvoton,npcm7xx-clock.h>
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    gpio8: gpio@...000 {
> +        compatible = "nuvoton,npcm750-sgpio";
> +        reg = <0x101000 0x200>;
> +        clocks = <&clk NPCM7XX_CLK_APB3>;
> +        interrupts = <GIC_SPI 19 IRQ_TYPE_LEVEL_HIGH>;
> +        bus-frequency = <8000000>;
> +        gpio-controller;
> +        #gpio-cells = <2>;
> +        nuvoton,input-ngpios = <64>;
> +        nuvoton,output-ngpios = <64>;
> +        status = "disabled";

I reminded you about this twice. So this is third time. Or maybe even
fourth?

Best regards,
Krzysztof