Re: [PATCH v5] iio: cros_ec: Add lid angle driver

[Gwendal Grignou]

On Fri, Mar 29, 2019 at 1:17 PM Guenter Roeck <groeck@xxxxxxxxxx> wrote:
>
> On Fri, Mar 29, 2019 at 1:08 PM Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
> >
> > Add a IIO driver that reports the angle between the lid and the base for
> > ChromeOS convertible device.
...
> > --- a/drivers/mfd/cros_ec_dev.c
> > +++ b/drivers/mfd/cros_ec_dev.c
> > @@ -297,13 +297,15 @@ static void cros_ec_sensors_register(struct
> > cros_ec_dev *ec)
> >
> >         resp = (struct ec_response_motion_sense *)msg->data;
> >         sensor_num = resp->dump.sensor_count;
> > -       /* Allocate 1 extra sensors in FIFO are needed */
> > -       sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell),
> > +       /*
> > +        * Allocate 2 extra sensors if lid angle sensor and/or FIFO are needed.
> > +        */
> > +       sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
> >                                GFP_KERNEL);
> >         if (sensor_cells == NULL)
> >                 goto error;
> >
> > -       sensor_platforms = kcalloc(sensor_num + 1,
> > +       sensor_platforms = kcalloc(sensor_num,
>
> I still don't understand why the "+ 1" is no longer needed. It seems
> to me that it would have to change to "+ 2".
"+1" was never needed to begin with FIFO device will never use a
struct cros_ec_sensor_platform. I mentioned it earlier:
https://www.spinics.net/lists/linux-iio/msg43157.html

Gwendal.
>
> Guenter
>
> >                                    sizeof(struct cros_ec_sensor_platform),
> >                                    GFP_KERNEL);
> >         if (sensor_platforms == NULL)
> > @@ -363,6 +365,11 @@ static void cros_ec_sensors_register(struct
> > cros_ec_dev *ec)
> >                 sensor_cells[id].name = "cros-ec-ring";
> >                 id++;
> >         }
> > +       if (cros_ec_check_features(ec,
> > +                               EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
> > +               sensor_cells[id].name = "cros-ec-lid-angle";
> > +               id++;
> > +       }
> >
> >         ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
> >                               NULL, 0, NULL);
> > --
> > 2.21.0.360.g471c308f928-goog