Re: [PATCH v2 1/2] i2c: core: Introduce i2c_client_get_device_id helper function

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

On Sun, 2022-11-06 at 17:22 +0000, Jonathan Cameron wrote:
> On Sun,  6 Nov 2022 17:42:24 +0100
> Angel Iglesias <ang.iglesiasg@gmail.com> 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>
> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> 
> Trivial comment inline - otherwise lgtm
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> Thanks,
> 
> > 
> > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
> > index b4edf10e8fd0..920676e62c22 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. The device must be bound to a driver or
> > + *         the function oopses.
> 
> Maybe don't state what happens otherwise if something changes to make it
> instead do something else unfortunate, this comment will need updating.
> "The device must be bound to a driver."

Sure, sorry for the trouble. I'll wait a bit for more comments and then send v3
fixed.

Thanks for your time,
Angel

> 
> > + *
> > + * 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);
> > +}
> > +EXPORT_SYMBOL_GPL(i2c_client_get_device_id);
> > +
> >  /* ----------------------------------------------------
> >   * the i2c address scanning function
> >   * Will not work for 10-bit addresses!
> > diff --git a/include/linux/i2c.h b/include/linux/i2c.h
> > index f7c49bbdb8a1..d84e0e99f084 100644
> > --- a/include/linux/i2c.h
> > +++ b/include/linux/i2c.h
> > @@ -189,6 +189,7 @@ s32 i2c_smbus_read_i2c_block_data_or_emulated(const
> > struct i2c_client *client,
> >                                               u8 *values);
> >  int i2c_get_device_id(const struct i2c_client *client,
> >                       struct i2c_device_identity *id);
> > +const struct i2c_device_id *i2c_client_get_device_id(const struct
> > i2c_client *client);
> >  #endif /* I2C */
> >  
> >  /**
>