linux-kernel - Re: [PATCH v2 03/10] gpio: raspberrypi-exp: Release firmware handle on unbind

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Date:   Mon, 26 Oct 2020 15:40:55 +0100
From:   Bartosz Golaszewski <bgolaszewski@...libre.com>
To:     Nicolas Saenz Julienne <nsaenzjulienne@...e.de>
Cc:     Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        LKML <linux-kernel@...r.kernel.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Florian Fainelli <f.fainelli@...il.com>,
        linux-pwm@...r.kernel.org, bcm-kernel-feedback-list@...adcom.com,
        arm-soc <linux-arm-kernel@...ts.infradead.org>,
        linux-devicetree <devicetree@...r.kernel.org>, wahrenst@....net,
        Linux Input <linux-input@...r.kernel.org>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Greg KH <gregkh@...uxfoundation.org>,
        devel@...verdev.osuosl.org, Philipp Zabel <p.zabel@...gutronix.de>,
        linux-gpio <linux-gpio@...r.kernel.org>,
        linux-clk <linux-clk@...r.kernel.org>,
        Stephen Boyd <sboyd@...nel.org>,
        linux-rpi-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 03/10] gpio: raspberrypi-exp: Release firmware handle
 on unbind

On Thu, Oct 22, 2020 at 5:59 PM Nicolas Saenz Julienne
<nsaenzjulienne@...e.de> wrote:
>
> Upon unbinding the device make sure we release RPi's firmware interface.
>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@...e.de>
> ---
>  drivers/gpio/gpio-raspberrypi-exp.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-raspberrypi-exp.c b/drivers/gpio/gpio-raspberrypi-exp.c
> index bb100e0124e6..c008336e1131 100644
> --- a/drivers/gpio/gpio-raspberrypi-exp.c
> +++ b/drivers/gpio/gpio-raspberrypi-exp.c
> @@ -231,8 +231,19 @@ static int rpi_exp_gpio_probe(struct platform_device *pdev)
>         rpi_gpio->gc.get = rpi_exp_gpio_get;
>         rpi_gpio->gc.set = rpi_exp_gpio_set;
>         rpi_gpio->gc.can_sleep = true;
> +       platform_set_drvdata(pdev, rpi_gpio);
>
> -       return devm_gpiochip_add_data(dev, &rpi_gpio->gc, rpi_gpio);
> +       return gpiochip_add_data(&rpi_gpio->gc, rpi_gpio);
> +}
> +
> +static int rpi_exp_gpio_remove(struct platform_device *pdev)
> +{
> +       struct rpi_exp_gpio *rpi_gpio = platform_get_drvdata(pdev);
> +
> +       gpiochip_remove(&rpi_gpio->gc);
> +       rpi_firmware_put(rpi_gpio->fw);
> +
> +       return 0;
>  }
>
>  static const struct of_device_id rpi_exp_gpio_ids[] = {
> @@ -247,6 +258,7 @@ static struct platform_driver rpi_exp_gpio_driver = {
>                 .of_match_table = of_match_ptr(rpi_exp_gpio_ids),
>         },
>         .probe  = rpi_exp_gpio_probe,
> +       .remove = rpi_exp_gpio_remove,
>  };
>  module_platform_driver(rpi_exp_gpio_driver);
>
> --
> 2.28.0
>

Why not introduce devm_rpi_firmware_get()? That would allow you to
keep the driver elegant without re-adding remove().

Bartosz