Re: [PATCH RFC v3] media: i2c: mt9p031: add OF support

[Sascha Hauer]

On Wed, May 08, 2013 at 12:37:29PM +0200, Laurent Pinchart wrote:
> Hi Prabhakar,
> 
> On Wednesday 08 May 2013 10:19:57 Prabhakar Lad wrote:
> > On Wed, May 8, 2013 at 7:32 AM, Laurent Pinchart wrote:
> > > On Tuesday 07 May 2013 15:10:36 Prabhakar Lad wrote:
> > >> On Mon, May 6, 2013 at 8:29 PM, Prabhakar Lad wrote:
> > >> > On Fri, May 3, 2013 at 8:04 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> > >> >> On Friday 03 May 2013, Prabhakar Lad wrote:
> > >> > [snip]
> > >> > 
> > >> >>> +}
> > >> >> 
> > >> >> Ok, good.
> > >> >> 
> > >> >>> @@ -955,7 +998,17 @@ static int mt9p031_probe(struct i2c_client
> > >> >>> *client,
> > >> >>> 
> > >> >>>         mt9p031->pdata = pdata;
> > >> >>>         mt9p031->output_control = MT9P031_OUTPUT_CONTROL_DEF;
> > >> >>>         mt9p031->mode2 = MT9P031_READ_MODE_2_ROW_BLC;
> > >> >>> 
> > >> >>> -       mt9p031->model = did->driver_data;
> > >> >>> +
> > >> >>> +       if (!client->dev.of_node) {
> > >> >>> +               mt9p031->model = (enum
> > >> >>> mt9p031_model)did->driver_data;
> > >> >>> +       } else {
> > >> >>> +               const struct of_device_id *of_id;
> > >> >>> +
> > >> >>> +               of_id =
> > >> >>> of_match_device(of_match_ptr(mt9p031_of_match),
> > >> >>> +                                       &client->dev);
> > >> >>> +               if (of_id)
> > >> >>> +                       mt9p031->model = (enum
> > >> >>> mt9p031_model)of_id->data;
> > >> >>> +       }
> > >> >>> 
> > >> >>>         mt9p031->reset = -1;
> > >> >> 
> > >> >> Is this actually required? I thought the i2c core just compared the
> > >> >> part of the "compatible" value after the first comma to the string, so
> > >> >> "mt9p031->model = (enum mt9p031_model)did->driver_data" should work
> > >> >> in both cases.

At least on v3.8 I just checked that 'did' is indeed NULL for the
devicetree case. Also I see no indication that i2c starts comparing
after the first comma in the string.

> > >> > 
> > >> > I am OK with "mt9p031->model = (enum mt9p031_model)did->driver_data"
> > >> > but I see still few drivers doing this, I am not sure for what reason.
> > >> > If everyone is OK with it I can drop the above change.
> > >> 
> > >> My bad, while booting with DT the i2c_device_id ie did in this case will
> > >> be NULL, so the above changes are required :-)
> > > 
> > > I've just tested your patch, and did isn't NULL when booting my
> > > Beagleboard with DT (on v3.9-rc5).
> > 
> > I am pretty much sure you tested it compatible property as "aptina,mt9p031"
> > if the compatible property is set to "aptina,mt9p031m" the did will be NULL.
> 
> I've tested both :-)

Sorry to nag, but did you use "aptina,mt9p031[m]" as a compatible string or did
you use "mt9p031[m]". With "aptina,..." 'did' should really be NULL.

Sascha

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