Re: [PATCH v2 03/10] gpio: aggregator: add read-only 'dev_name' configfs attribute

[Bartosz Golaszewski <brgl@xxxxxxxx>]

On Mon, Feb 3, 2025 at 4:12 AM Koichiro Den <koichiro.den@xxxxxxxxxxxxx> wrote:
>
> Add a read-only 'dev_name' attribute to configfs interface, which
> exposes the platform bus device name. Users can easily identify which
> gpiochip<N> has been created as follows:
>
> $ cat /sys/kernel/config/gpio-aggregator/<aggregator-name>/dev_name
>   gpio-aggregator.0
> $ ls -d /sys/devices/platform/gpio-aggregator.0/gpiochip*
>   gpiochip3
>
> Signed-off-by: Koichiro Den <koichiro.den@xxxxxxxxxxxxx>
> ---
>  drivers/gpio/gpio-aggregator.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
>
> diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c
> index c63cf3067ce7..76d3a8677308 100644
> --- a/drivers/gpio/gpio-aggregator.c
> +++ b/drivers/gpio/gpio-aggregator.c
> @@ -732,6 +732,23 @@ static struct configfs_attribute *gpio_aggr_line_attrs[] = {
>         NULL
>  };
>
> +static ssize_t
> +gpio_aggr_device_dev_name_show(struct config_item *item, char *page)
> +{
> +       struct gpio_aggregator *aggr = to_gpio_aggregator(item);
> +       struct platform_device *pdev;
> +
> +       guard(mutex)(&aggr->lock);
> +
> +       pdev = aggr->pdev;
> +       if (pdev)
> +               return sprintf(page, "%s\n", dev_name(&pdev->dev));
> +
> +       return sprintf(page, "%s.%d\n", DRV_NAME, aggr->id);
> +}
> +
> +CONFIGFS_ATTR_RO(gpio_aggr_device_, dev_name);
> +
>  static ssize_t
>  gpio_aggr_device_live_show(struct config_item *item, char *page)
>  {
> @@ -781,6 +798,7 @@ gpio_aggr_device_live_store(struct config_item *item, const char *page,
>  CONFIGFS_ATTR(gpio_aggr_device_, live);
>
>  static struct configfs_attribute *gpio_aggr_device_attrs[] = {
> +       &gpio_aggr_device_attr_dev_name,
>         &gpio_aggr_device_attr_live,
>         NULL
>  };
> --
> 2.45.2
>

I don't understand why this isn't part of the previous patch?

Bart