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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Fri, 28 May 2021 01:51:35 +0200
Message-ID: <CACRpkdZFcFuT9rdrc8BfEBmhy0--9uLMSJWfr=A+nU117_BT8A@mail.gmail.com>
Subject: Re: [PATCH v2 1/4] dt-bindings: aspeed-sgpio: Convert txt bindings to yaml.
To:     Steven Lee <steven_lee@aspeedtech.com>
Cc:     Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        Rob Herring <robh+dt@kernel.org>,
        Joel Stanley <joel@jms.id.au>,
        Andrew Jeffery <andrew@aj.id.au>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        "moderated list:ARM/ASPEED MACHINE SUPPORT" 
        <linux-arm-kernel@lists.infradead.org>,
        "moderated list:ARM/ASPEED MACHINE SUPPORT" 
        <linux-aspeed@lists.ozlabs.org>,
        open list <linux-kernel@vger.kernel.org>,
        Hongwei Zhang <Hongweiz@ami.com>,
        Ryan Chen <ryan_chen@aspeedtech.com>,
        Billy Tsai <billy_tsai@aspeedtech.com>
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On Thu, May 27, 2021 at 2:55 AM Steven Lee <steven_lee@aspeedtech.com> wrote:

> SGPIO bindings should be converted as yaml format.
> In addition to the file conversion, a new property max-ngpios is
> added in the yaml file as well.
> The new property is required by the enhanced sgpio driver for
> making the configuration of the max number of gpio pins more flexible.
>
> Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
(...)
> +  max-ngpios:
> +    description:
> +      represents the number of actual hardware-supported GPIOs (ie,
> +      slots within the clocked serial GPIO data). Since each HW GPIO is both an
> +      input and an output, we provide max_ngpios * 2 lines on our gpiochip
> +      device. We also use it to define the split between the inputs and
> +      outputs; the inputs start at line 0, the outputs start at max_ngpios.
> +    minimum: 0
> +    maximum: 128

Why can this not be derived from the compatible value?

Normally there should be one compatible per hardware variant
of the block. And this should be aligned with that, should it not?

If this is not the case, maybe more detailed compatible strings
are needed, maybe double compatibles with compatible per
family and SoC?

Yours,
Linus Walleij