Re: [PATCH 4/4] iio: adc: ina2xx: Use label proper for device identification

[Jonathan Cameron <jic23@kernel.org>]

On Wed, 21 Aug 2019 11:12:00 +0200
Michal Simek <michal.simek@xilinx.com> wrote:

> On 21. 08. 19 4:11, Phil Reid wrote:
> > On 20/08/2019 22:11, Michal Simek wrote:  
> >> Add support for using label property for easier device identification via
> >> iio framework.
> >>
> >> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> >> ---
> >>
> >>   drivers/iio/adc/ina2xx-adc.c | 2 +-
> >>   1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
> >> index 7c7c63677bf4..077c54915f70 100644
> >> --- a/drivers/iio/adc/ina2xx-adc.c
> >> +++ b/drivers/iio/adc/ina2xx-adc.c
> >> @@ -1033,7 +1033,7 @@ static int ina2xx_probe(struct i2c_client *client,
> >>       snprintf(chip->name, sizeof(chip->name), "%s-%s",
> >>            client->name, dev_name(&client->dev));
> >>   -    indio_dev->name = chip->name;
> >> +    indio_dev->name = of_get_property(np, "label", NULL) ? : chip->name;
> >>       indio_dev->setup_ops = &ina2xx_setup_ops;
> >>         buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
> >>  
> > I like this personally. It'd be nice if it was a core function so
> > it could be an opt in to any iio device.
> > 
> > Don't know how well received that'd be thou.
> >   
I'm not particularly keen on changing the semantics of existing
ABI, but how about adding new ABI to provide this?

/sys/bus/iio/devices/iio\:device0/label for example?

I haven't thought about it in depth yet though.  If you spin
a patch with that and the DT docs we'll be more likely to get
a view from DT maintainers if this is acceptable use of label.

Thanks

Jonathan

> 
> Something like this?
> 
> diff --git a/drivers/iio/industrialio-core.c
> b/drivers/iio/industrialio-core.c
> index 524a686077ca..d21b495d36a1 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1647,6 +1647,9 @@ int __iio_device_register(struct iio_dev
> *indio_dev, struct module *this_mod)
>         if (!indio_dev->dev.of_node && indio_dev->dev.parent)
>                 indio_dev->dev.of_node = indio_dev->dev.parent->of_node;
> 
> +       indio_dev->name = of_get_property(indio_dev->dev.of_node,
> "label", NULL) ? :
> +                                         indio_dev->name;
> +
>         ret = iio_check_unique_scan_index(indio_dev);
>         if (ret < 0)
>                 return ret;
> 
> 
> M