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

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Message-ID: <CAMpxmJWTuREXQKLtc37uo6+6aG_-Tkb-P+8Ozjkz+7-DixvpDQ@mail.gmail.com>
Date:   Mon, 26 Oct 2020 15:45:17 +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 Mon, Oct 26, 2020 at 3:42 PM Nicolas Saenz Julienne
<nsaenzjulienne@...e.de> wrote:
>
> On Mon, 2020-10-26 at 15:40 +0100, Bartosz Golaszewski wrote:
> > 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().
>
> I like the idea, I'll look into it.
>
> Thanks,
> Nicolas
>

If you can't do it for some reason, then even using devm_add_action() is fine.

Bartosz