linux-kernel - Re: [PATCH v4 05/10] gpio: swnode: allow referencing GPIO chips by firmware nodes

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Message-ID: <aQh76Qo-PAunVLcr@smile.fi.intel.com>
Date: Mon, 3 Nov 2025 11:54:49 +0200
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Linus Walleij <linus.walleij@...aro.org>,
	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>
Subject: Re: [PATCH v4 05/10] gpio: swnode: allow referencing GPIO chips by
 firmware nodes

On Mon, Nov 03, 2025 at 10:35:25AM +0100, Bartosz Golaszewski wrote:
> 
> When doing a software node lookup, we require both the fwnode that
> references a GPIO chip as well as the node associated with that chip to
> be software nodes. However, we now allow referencing generic firmware
> nodes from software nodes in driver core so we should allow the same in
> GPIO core. Make the software node name check optional and dependent on
> whether the referenced firmware node is a software node. If it's not,
> just continue with the lookup.

...

>  	gdev_node = to_software_node(fwnode);
> -	if (!gdev_node || !gdev_node->name)
> -		return ERR_PTR(-EINVAL);

The whole patch can be done in two lines (1 changed, 1 added):

		goto out_fwnode_lookup;

> -	/*
> -	 * Check for a special node that identifies undefined GPIOs, this is
> -	 * primarily used as a key for internal chip selects in SPI bindings.
> -	 */
> -	if (IS_ENABLED(CONFIG_GPIO_SWNODE_UNDEFINED) &&
> -	    !strcmp(gdev_node->name, GPIOLIB_SWNODE_UNDEFINED_NAME))
> -		return ERR_PTR(-ENOENT);
> +	if (gdev_node && gdev_node->name) {
> +		/*
> +		 * Check for a special node that identifies undefined GPIOs, this is
> +		 * primarily used as a key for internal chip selects in SPI bindings.
> +		 */
> +		if (IS_ENABLED(CONFIG_GPIO_SWNODE_UNDEFINED) &&
> +		    !strcmp(gdev_node->name, GPIOLIB_SWNODE_UNDEFINED_NAME))
> +			return ERR_PTR(-ENOENT);
> +	}

out_fwnode_lookup:

>  	gdev = gpio_device_find_by_fwnode(fwnode);
>  	return gdev ?: ERR_PTR(-EPROBE_DEFER);

-- 
With Best Regards,
Andy Shevchenko