linux-kernel - Re: [PATCH v4 04/10] gpio: swnode: don't use the swnode's name as the key for GPIO lookup

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Message-ID: <aRyf7qDdHKABppP8@opensource.cirrus.com>
Date: Tue, 18 Nov 2025 16:33:50 +0000
From: Charles Keepax <ckeepax@...nsource.cirrus.com>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Linus Walleij <linus.walleij@...aro.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Daniel Scally <djrscally@...il.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Danilo Krummrich <dakr@...nel.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Krzysztof Kozlowski <krzk@...nel.org>, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org,
        Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
        patches@...nsource.cirrus.com
Subject: Re: [PATCH v4 04/10] gpio: swnode: don't use the swnode's name as
 the key for GPIO lookup

On Mon, Nov 03, 2025 at 10:35:24AM +0100, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> 
> Looking up a GPIO controller by label that is the name of the software
> node is wonky at best - the GPIO controller driver is free to set
> a different label than the name of its firmware node. We're already being
> passed a firmware node handle attached to the GPIO device to
> swnode_get_gpio_device() so use it instead for a more precise lookup.
> 
> Acked-by: Linus Walleij <linus.walleij@...aro.org>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> ---
>  drivers/gpio/gpiolib-swnode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpio/gpiolib-swnode.c b/drivers/gpio/gpiolib-swnode.c
> index f21dbc28cf2c8c2d06d034b7c89d302cc52bb9b5..e3806db1c0e077d76fcc71a50ca40bbf6872ca40 100644
> --- a/drivers/gpio/gpiolib-swnode.c
> +++ b/drivers/gpio/gpiolib-swnode.c
> @@ -41,7 +41,7 @@ static struct gpio_device *swnode_get_gpio_device(struct fwnode_handle *fwnode)
>  	    !strcmp(gdev_node->name, GPIOLIB_SWNODE_UNDEFINED_NAME))
>  		return ERR_PTR(-ENOENT);
>  
> -	gdev = gpio_device_find_by_label(gdev_node->name);
> +	gdev = gpio_device_find_by_fwnode(fwnode);
>  	return gdev ?: ERR_PTR(-EPROBE_DEFER);
>  }

One small problem is this does break drivers/spi/spi-cs42l43.c.
That driver has to register some swnodes to specify some GPIO
chip selects due to some squiffy ACPI from Windows land. Currently
it relies on the sw node being called cs42l43-pinctrl to match
the driver.

I guess that is not quite the right way to handle that but its
not clear to me how to link the software node properties to the
pinctrl otherwise, anyone have any pointers there?

Note: There are a reasonable amount of shipping laptops this will
break.

Thanks,
Charles