Re: [PATCH v3 00/13] Introduce configfs-based interface for gpio-aggregator

[Bartosz Golaszewski]

On Sun, Feb 16, 2025 at 1:58 PM Koichiro Den <koichiro.den@xxxxxxxxxxxxx> wrote:
>
> This patch series introduces a configfs-based interface to gpio-aggregator
> to address limitations in the existing 'new_device' interface.
>
> The existing 'new_device' interface has several limitations:
>
>   Issue#1. No way to determine when GPIO aggregator creation is complete.
>   Issue#2. No way to retrieve errors when creating a GPIO aggregator.
>   Issue#3. No way to trace a GPIO line of an aggregator back to its
>            corresponding physical device.
>   Issue#4. The 'new_device' echo does not indicate which virtual
>            gpiochip<N> was created.
>   Issue#5. No way to assign names to GPIO lines exported through an
>            aggregator.
>
> Although Issue#1 to #3 could technically be resolved easily without
> configfs, using configfs offers a streamlined, modern, and extensible
> approach, especially since gpio-sim and gpio-virtuser already utilize
> configfs.
>
> This v3 patch series includes 13 patches:
>
>   Patch#1-7: Prepare for Patch#8
>              * #1: Prepare for the following patches.
>              * #2: Fix an issue that was spotted during v3 preparation.
>              * #3: Add gpio-pseudo.[ch] to reduce code duplications.
>              * #4: Update gpio-sim to use gpio-pseudo.[ch].
>              * #5: Update gpio-virtuser to use gpio-pseudo.[ch].
>              * #6: Update gpio-aggregator to use gpio-pseudo.[ch].
>              * #7: Add aggr_alloc() to reduce code duplication.

Please don't ram this new functionality into an unrelated series.
Split it into the gpio-pseudo code, factoring out common parts and
converting existing drivers, then send the aggregator series saying it
depends on the former. Otherwise it gets way too complex to review.

Bartosz