linux-kernel - Re: [PATCH 47/49] regmap-irq: Add get_irq

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Date:   Tue, 21 Jun 2022 11:51:16 +0200
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Aidan MacDonald <aidanmacdonald.0x0@...il.com>
Cc:     Mark Brown <broonie@...nel.org>, Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Banajit Goswami <bgoswami@...eaurora.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
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        MyungJoo Ham <myungjoo.ham@...sung.com>,
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        Linus Walleij <linus.walleij@...aro.org>,
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Subject: Re: [PATCH 47/49] regmap-irq: Add get_irq_reg() callback

On Mon, Jun 20, 2022 at 10:12 PM Aidan MacDonald
<aidanmacdonald.0x0@...il.com> wrote:
>
> Replace the internal sub_irq_reg() function with a public callback
> that drivers can use when they have more complex register layouts.
> The default implementation is regmap_irq_get_irq_reg_linear(), used
> if the chip doesn't provide its own callback.

...

> +       /*
> +        * While possible that a user-defined get_irq_reg callback might be

->get_irq_reg()

> +        * linear enough to support bulk reads, most of the time it won't.
> +        * Therefore only allow them if the default callback is being used.
> +        */
>         return !map->use_single_read && map->reg_stride == 1 &&
> -               data->irq_reg_stride == 1;
> +               data->irq_reg_stride == 1 &&
> +               data->get_irq_reg == regmap_irq_get_irq_reg_linear;

If initially this had been as

return _reg_stride && irq_reg_stride &&
  !map->use_single_read;

you would have done less changes by squeezing a new condition just in
between the other two. It will preserve the grouping of the checks as
well.

>  }

...

> +               /*
> +                * Note we can't use get_irq_reg() here because the offsets

->get_irq_reg()

> +                * in 'subreg' are *not* interchangeable with indices.
> +                */

...

> +                       /*
> +                        * For not_fixed_stride, don't use get_irq_reg().

Ditto.

> +                        * It would produce an incorrect result.
> +                        */

...

> +                               reg = chip->main_status +
> +                                       (i * map->reg_stride *
> +                                        data->irq_reg_stride);

Parentheses are not necessary. And perhaps the last two can be put on
a single line.

...

> +       /*
> +        * NOTE: This is for backward compatibility only and will be removed

FIXME ?

> +        * when not_fixed_stride is dropped (it's only used by qcom-pm8008).
> +        */

-- 
With Best Regards,
Andy Shevchenko