Re: [RFC PATCH 1/2] i2c: core: Introduce i2c_client_get_device_id helper function

[Angel Iglesias <ang.iglesiasg@gmail.com>]

On Tue, 2022-11-01 at 15:54 +0100, Uwe Kleine-König wrote:
> On Sun, Oct 30, 2022 at 06:52:18PM +0100, Angel Iglesias wrote:
> > Introduces new helper function to aid in .probe_new() refactors. In order
> > to use existing i2c_get_device_id() on the probe callback, the device
> > match table needs to be accessible in that function, which would require
> > bigger refactors in some drivers using the deprecated .probe callback.
> > 
> > This issue was discussed in more detail in the IIO mailing list.
> > 
> > Link:
> > https://lore.kernel.org/all/20221023132302.911644-11-u.kleine-koenig@pengutronix.de/
> > Suggested-by: Nuno Sá <noname.nuno@gmail.com>
> > Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Suggested-by: Jonathan Cameron <jic23@kernel.org>
> > Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>
> > ---
> >  drivers/i2c/i2c-core-base.c | 15 +++++++++++++++
> >  include/linux/i2c.h         |  1 +
> >  2 files changed, 16 insertions(+)
> > 
> > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> > index b4edf10e8fd0..e6623226e393 100644
> > --- a/drivers/i2c/i2c-core-base.c
> > +++ b/drivers/i2c/i2c-core-base.c
> > @@ -2236,6 +2236,21 @@ int i2c_get_device_id(const struct i2c_client
> > *client,
> >  }
> >  EXPORT_SYMBOL_GPL(i2c_get_device_id);
> >  
> > +/**
> > + * i2c_client_get_device_id - get the driver match table entry of a device
> > + * @client: the device to query
> > + *
> > + * Returns a pointer to the matching entry if found, NULL otherwise.
> > + */
> > +const struct i2c_device_id *i2c_client_get_device_id(const struct
> > i2c_client *client)
> > +{
> > +       const struct i2c_driver *drv = to_i2c_driver(client->dev.driver);
> > +
> > +       return i2c_match_id(drv->id_table, client);
> > +
> 
> I'd drop the empty line after the return. Is it worth to note in a
> comment that it only works for bound clients? (Oopses otherwise)

Yup, my bad, that newline shouldn't be there.
Sure, seems reasonable to leave warn just in case.

Kind regards,
Angel

> Best regards
> Uwe
>