Re: [PATCH v2 3/3] media: imx214: Add new control with V4L2_CID_UNIT_CELL_SIZE

[Ricardo Ribalda Delgado <ribalda@kernel.org>]

Hi Philipp

On Thu, Aug 22, 2019 at 11:31 AM Philipp Zabel <p.zabel@pengutronix.de> wrote:
>
> On Tue, 2019-08-20 at 11:40 +0200, Ricardo Ribalda Delgado wrote:
> > According to the product brief, the unit cell size is 1120 nanometers^2.
> >
> > https://www.sony-semicon.co.jp/products_en/IS/sensor1/img/products/ProductBrief_IMX214_20150428.pdf
> >
> > Signed-off-by: Ricardo Ribalda Delgado <ribalda@kernel.org>
> > ---
> >  drivers/media/i2c/imx214.c | 23 +++++++++++++++++++++++
> >  1 file changed, 23 insertions(+)
> >
> > diff --git a/drivers/media/i2c/imx214.c b/drivers/media/i2c/imx214.c
> > index 159a3a604f0e..cc0a013ba7da 100644
> > --- a/drivers/media/i2c/imx214.c
> > +++ b/drivers/media/i2c/imx214.c
> > @@ -47,6 +47,7 @@ struct imx214 {
> >       struct v4l2_ctrl *pixel_rate;
> >       struct v4l2_ctrl *link_freq;
> >       struct v4l2_ctrl *exposure;
> > +     struct v4l2_ctrl *unit_size;
>
> This is never used.
>
> Neither are pixel_rate and exposure, it appears. And link_freq is only
> used locally in imx214_probe to set the read-only flag.
>
> >
> >       struct regulator_bulk_data      supplies[IMX214_NUM_SUPPLIES];
> >
> > @@ -941,6 +942,26 @@ static int __maybe_unused imx214_resume(struct device *dev)
> >       return ret;
> >  }
> >
> > +static void unit_size_init(const struct v4l2_ctrl *ctrl, u32 idx,
> > +                  union v4l2_ctrl_ptr ptr)
> > +{
> > +     ptr.p_area->width = 1120;
> > +     ptr.p_area->height = 1120;
> > +}
> > +
> > +static const struct v4l2_ctrl_type_ops unit_size_ops = {
> > +     .init = unit_size_init,
> > +};
> > +
> > +static struct v4l2_ctrl *new_unit_size_ctrl(struct v4l2_ctrl_handler *handler)
> > +{
> > +     static struct v4l2_ctrl_config ctrl = {
> > +             .id = V4L2_CID_UNIT_CELL_SIZE,
> > +             .type_ops = &unit_size_ops,
> > +     };
> > +
> > +     return v4l2_ctrl_new_custom(handler, &ctrl, NULL);
> > +}
> >  static int imx214_probe(struct i2c_client *client)
> >  {
> >       struct device *dev = &client->dev;
> > @@ -1029,6 +1050,8 @@ static int imx214_probe(struct i2c_client *client)
> >                                            V4L2_CID_EXPOSURE,
> >                                            0, 3184, 1, 0x0c70);
> >
> > +     imx214->unit_size = new_unit_size_ctrl(&imx214->ctrls);
> > +
> >       ret = imx214->ctrls.error;
> >       if (ret) {
> >               dev_err(&client->dev, "%s control init failed (%d)\n",
>
> This seems like a lot of parts to assemble in every sensor driver just
> to provide a constant area control. Should this be turned into a
> v4l2_ctrl_new_area helper that takes a const struct v4l2_area as an
> argument?

I agree, I was planning on making a helper afterwards ;). I do not
mind adding it to this series.

>
>         static const struct v4l2_area unit_cell_size = {
>                 .width = 1120,
>                 .height = 1120
>         };
>
>         v4l2_ctrl_new_area(&imx214->ctrls, V4L2_CID_UNIT_CELL_SIZE,
>                            &unit_cell_size);
>
> regards
> Philipp