R: [PATCH v2] gpiolib: Disallow identical line names in the same chip

[Flavio Suligoi <f.suligoi@xxxxxxx>]

Hi Linus and Bartosz,

> On Wed, Jan 6, 2021 at 11:09 AM Bartosz Golaszewski
> <bgolaszewski@xxxxxxxxxxxx> wrote:
> 
> > I can do it alright. But in the context of user-space I think this
> > doesn't really change anything. DT users still can use non-unique
> > names and libgpiod still has to account for that if the API is to be
> > considered correct. Is this change really useful? How does it affect
> > ACPI users that already define non-unique names?
> 
> For hardware description instances the problem remains: device tree
> line-names and device properties can be non-unique.
> 
> What it solves is to enforce unique line names for gpio chips with
> the struct gpio_chip .names array set to some names, that each
> name in this array must be unique.
> 
> This happens for example when two USB FTDI converters
> with the same GPIO lines are plugged in. Each chip can have a
> "TX" line but it can no longer have two "TX" lines.
> 
> Yours,
> Linus Walleij

about the duplicate line names, what do you think
about adding to the command "gpiofind" of libgpiod tools,
the possibility to discover all the duplicate gpio lines?

For example, something like the following:

# gpiofind button_1
gpiochip0 20
gpiochip0 22 (duplicate)
gpiochip2 12 (duplicate)
#

Best regards,
Flavio Suligoi