linux-kernel - Re: [PATCH 10/62] gpio: gpio-bd9571mwv: Use new GPIO_LINE

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Date:   Tue, 5 Nov 2019 11:31:18 +0100
From:   Geert Uytterhoeven <geert@...ux-m68k.org>
To:     Matti Vaittinen <matti.vaittinen@...rohmeurope.com>
Cc:     Matti Vaittinen <mazziesaccount@...il.com>,
        Marek Vasut <marek.vasut+renesas@...il.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Linux-Renesas <linux-renesas-soc@...r.kernel.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>
Subject: Re: [PATCH 10/62] gpio: gpio-bd9571mwv: Use new GPIO_LINE_DIRECTION

Hi Matti,

On Tue, Nov 5, 2019 at 11:15 AM Matti Vaittinen
<matti.vaittinen@...rohmeurope.com> wrote:
> It's hard for occasional GPIO code reader/writer to know if values 0/1
> equal to IN or OUT. Use defined GPIO_LINE_DIRECTION_IN and
> GPIO_LINE_DIRECTION_OUT to help them out.
>
> NOTE: This commit also changes the return value for direction get
> to equal 1 for direction INPUT. Prior this commit the driver returned
> different values depending on GPIO pin for the INPUT state.

Indeed. Which means you cannot assume the assembler output
before/after is identical (which it should be for most changes).

> Signed-off-by: Matti Vaittinen <matti.vaittinen@...rohmeurope.com>

Reviewed-by: Geert Uytterhoeven <geert+renesas@...der.be>

> --- a/drivers/gpio/gpio-bd9571mwv.c
> +++ b/drivers/gpio/gpio-bd9571mwv.c
> @@ -37,8 +37,10 @@ static int bd9571mwv_gpio_get_direction(struct gpio_chip *chip,
>         ret = regmap_read(gpio->bd->regmap, BD9571MWV_GPIO_DIR, &val);
>         if (ret < 0)
>                 return ret;

Nit: I'd keep the blank line here.

> +       if (val & BIT(offset))
> +               return GPIO_LINE_DIRECTION_IN;
>
> -       return val & BIT(offset);
> +       return GPIO_LINE_DIRECTION_OUT;
>  }
>
>  static int bd9571mwv_gpio_direction_input(struct gpio_chip *chip,

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@...ux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds