linux-kernel - Re: [RFT PATCH 15/21] arm: omap1: ams-delta: stop using gpiochip

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Message-ID: <CAMRc=MeBKovkC-VbvWNJWk_UjU4FGguEW7gy=L-2saA7kiPijQ@mail.gmail.com>
Date:   Wed, 4 Oct 2023 13:59:31 +0200
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     Aaro Koskinen <aaro.koskinen@....fi>,
        Janusz Krzysztofik <jmkrzyszt@...il.com>,
        Tony Lindgren <tony@...mide.com>,
        Russell King <linux@...linux.org.uk>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Dipen Patel <dipenp@...dia.com>,
        Thierry Reding <thierry.reding@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Mark Gross <markgross@...nel.org>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-omap@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-gpio@...r.kernel.org,
        linux-acpi@...r.kernel.org, timestamp@...ts.linux.dev,
        linux-tegra@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [RFT PATCH 15/21] arm: omap1: ams-delta: stop using gpiochip_find()

On Tue, Sep 5, 2023 at 8:53 PM Bartosz Golaszewski <brgl@...ev.pl> wrote:
>
> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
>
> gpiochip_find() is going away as it's not hot-unplug safe. This platform
> is not affected by any of the related problems as this GPIO controller
> cannot really go away but in order to finally remove this function, we
> need to convert it to using gpio_device_find() as well.
>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> ---
>  arch/arm/mach-omap1/board-ams-delta.c | 36 +++++++++++++--------------
>  1 file changed, 17 insertions(+), 19 deletions(-)
>
> diff --git a/arch/arm/mach-omap1/board-ams-delta.c b/arch/arm/mach-omap1/board-ams-delta.c
> index 9808cd27e2cf..a28ea6ac1eba 100644
> --- a/arch/arm/mach-omap1/board-ams-delta.c
> +++ b/arch/arm/mach-omap1/board-ams-delta.c
> @@ -560,22 +560,6 @@ static struct gpiod_lookup_table *ams_delta_gpio_tables[] __initdata = {
>         &ams_delta_nand_gpio_table,
>  };
>
> -/*
> - * Some drivers may not use GPIO lookup tables but need to be provided
> - * with GPIO numbers.  The same applies to GPIO based IRQ lines - some
> - * drivers may even not use GPIO layer but expect just IRQ numbers.
> - * We could either define GPIO lookup tables then use them on behalf
> - * of those devices, or we can use GPIO driver level methods for
> - * identification of GPIO and IRQ numbers. For the purpose of the latter,
> - * defina a helper function which identifies GPIO chips by their labels.
> - */
> -static int gpiochip_match_by_label(struct gpio_chip *chip, void *data)
> -{
> -       char *label = data;
> -
> -       return !strcmp(label, chip->label);
> -}
> -
>  static struct gpiod_hog ams_delta_gpio_hogs[] = {
>         GPIO_HOG(LATCH2_LABEL, LATCH2_PIN_KEYBRD_DATAOUT, "keybrd_dataout",
>                  GPIO_ACTIVE_HIGH, GPIOD_OUT_LOW),
> @@ -615,14 +599,28 @@ static void __init modem_assign_irq(struct gpio_chip *chip)
>   */
>  static void __init omap_gpio_deps_init(void)
>  {
> +       struct gpio_device *gdev;
>         struct gpio_chip *chip;
>
> -       chip = gpiochip_find(OMAP_GPIO_LABEL, gpiochip_match_by_label);
> -       if (!chip) {
> -               pr_err("%s: OMAP GPIO chip not found\n", __func__);
> +       /*
> +        * Some drivers may not use GPIO lookup tables but need to be provided
> +        * with GPIO numbers. The same applies to GPIO based IRQ lines - some
> +        * drivers may even not use GPIO layer but expect just IRQ numbers.
> +        * We could either define GPIO lookup tables then use them on behalf
> +        * of those devices, or we can use GPIO driver level methods for
> +        * identification of GPIO and IRQ numbers.
> +        *
> +        * This reference will be leaked but that's alright as this device
> +        * never goes down.
> +        */
> +       gdev = gpio_device_find_by_label(OMAP_GPIO_LABEL);
> +       if (!gdev) {
> +               pr_err("%s: OMAP GPIO device not found\n", __func__);
>                 return;
>         }
>
> +       chip = gpio_device_get_chip(gdev);
> +
>         /*
>          * Start with FIQ initialization as it may have to request
>          * and release successfully each OMAP GPIO pin in turn.
> --
> 2.39.2
>

Patch applied, thanks!

Bart