Re: [PATCH 1/3] IIO: st_accel_i2c.c: Use fallback if DT/ACPI enum failed

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Mon, 2 Jul 2018 08:53:00 +0200
Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> wrote:

> On Sat, 30 Jun 2018, Jonathan Cameron wrote:
> 
> > On Fri, 29 Jun 2018 10:10:10 +0200
> > Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> wrote:
> >  
> >> Currently, the driver bails out if not explicitly referred to in
> >> DT or ACPI tables. This prevents fallback mechanisms from coming
> >> into effect, e.g. I2C device ID table match via DT or ACPI
> >> PRP0001 HID. However DT/ACPI enum should take precedence over
> >> the fallback, so evaluate that first.
> >>
> >> Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>  
> >
> > Is the change to probe_new actually related to the rest of the change?
> >
> > I can't immediately see why...  If not I would prefer that as a separate
> > change.  
> 
> Well, it is, because the id table pointer of the old probe() is not 
> used any more.
Hmm. Fair enough, kind of incidental cleanup rather than anything more.

J

> 
> >  
> >> ---
> >>  drivers/iio/accel/st_accel_i2c.c | 21 ++++++++++++---------
> >>  1 file changed, 12 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/drivers/iio/accel/st_accel_i2c.c b/drivers/iio/accel/st_accel_i2c.c
> >> index 6bdec8c451e0..e360da407027 100644
> >> --- a/drivers/iio/accel/st_accel_i2c.c
> >> +++ b/drivers/iio/accel/st_accel_i2c.c
> >> @@ -138,8 +138,7 @@ static const struct i2c_device_id st_accel_id_table[] = {
> >>  };
> >>  MODULE_DEVICE_TABLE(i2c, st_accel_id_table);
> >>
> >> -static int st_accel_i2c_probe(struct i2c_client *client,
> >> -						const struct i2c_device_id *id)
> >> +static int st_accel_i2c_probe(struct i2c_client *client)
> >>  {
> >>  	struct iio_dev *indio_dev;
> >>  	struct st_sensor_data *adata;
> >> @@ -156,14 +155,18 @@ static int st_accel_i2c_probe(struct i2c_client *client,
> >>  					 client->name, sizeof(client->name));
> >>  	} else if (ACPI_HANDLE(&client->dev)) {
> >>  		ret = st_sensors_match_acpi_device(&client->dev);
> >> -		if ((ret < 0) || (ret >= ST_ACCEL_MAX))
> >> -			return -ENODEV;
> >> -
> >> -		strlcpy(client->name, st_accel_id_table[ret].name,
> >> +		if ((ret >= 0) && (ret < ST_ACCEL_MAX))
> >> +			strlcpy(client->name, st_accel_id_table[ret].name,
> >>  				sizeof(client->name));
> >> -	} else if (!id)
> >> -		return -ENODEV;
> >> +	}
> >>
> >> +	/*
> >> +	 * If OF and ACPI enumeration failed, there could still be platform
> >> +	 * information via fallback enumeration or explicit instantiation, so
> >> +	 * check if id table has been matched via client->name.
> >> +	 */
> >> +	if (!client->name)
> >> +		return -ENODEV;
> >>
> >>  	st_sensors_i2c_configure(indio_dev, client, adata);
> >>
> >> @@ -187,7 +190,7 @@ static struct i2c_driver st_accel_driver = {
> >>  		.of_match_table = of_match_ptr(st_accel_of_match),
> >>  		.acpi_match_table = ACPI_PTR(st_accel_acpi_match),
> >>  	},
> >> -	.probe = st_accel_i2c_probe,
> >> +	.probe_new = st_accel_i2c_probe,
> >>  	.remove = st_accel_i2c_remove,
> >>  	.id_table = st_accel_id_table,
> >>  };  
> >
> >  
> --
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