Re: [PATCH 1/3 v5] gpio: pcf857x: Name instance after dev_name()

[Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>]

On Tue, Jun 15, 2021 at 5:01 PM Linus Walleij <linus.walleij@xxxxxxxxxx> wrote:
>
> Put the label on this gpio_chip from the dev_name() instead of
> the client name.
>
> The client name will be pcf8574 etc for all instances even if
> there are several chips on a system.
>
> This manifests on the DaVinci DM6467 (non-devicetree) which
> will contain 3 different pcf8574 devices that as a result cannot
> be told apart because they are all named "pcf8574", affecting
> the GPIO descriptor tables which need a unique label per chip.
>
> By passing in .dev_name in the struct i2c_board_info we can
> explicitly name each instance and use that to discern the chips
> when using board files.
>
> Cc: Sekhar Nori <nsekhar@xxxxxx>
> Cc: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> ChangeLog ->v5:
> - New patch to deal with the chip label
> ---
>  drivers/gpio/gpio-pcf857x.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c
> index b7568ee33696..2271ec86e414 100644
> --- a/drivers/gpio/gpio-pcf857x.c
> +++ b/drivers/gpio/gpio-pcf857x.c
> @@ -311,7 +311,7 @@ static int pcf857x_probe(struct i2c_client *client,
>         if (status < 0)
>                 goto fail;
>
> -       gpio->chip.label = client->name;
> +       gpio->chip.label = dev_name(&client->dev);
>
>         gpio->client = client;
>         i2c_set_clientdata(client, gpio);
> --
> 2.31.1
>

This makes sense but the i2c names are often not very descriptive. How
about adding a DEVID_AUTO/DEVID_NONE like mechanism to GPIO labels?
Nvmem has a thing like that precisely because labels can repeat.

Bart