Re: camera subdevice support was Re: [PATCH 1/4] v4l2: device_register_subdev_nodes: allow calling multiple times

Pavel Machek
2017-03-04T19:05:12Z

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On Sat 2017-03-04 14:30:11, Sakari Ailus wrote:
> On Sat, Mar 04, 2017 at 09:55:51AM +0100, Pavel Machek wrote:
> > Dobry den! :-)
>
> Huomenta! :-)

Dobry vecer! :-).

> > > Good point. Still there may be other ways to move the lens than the voice
> > > coil (which sure is cheap), so how about "flash" and "lens-focus"?
> >
> > Ok, so something like this? (Yes, needs binding documentation and you
> > wanted it in the core.. can fix.)
> >
> > BTW, fwnode_handle_put() seems to be missing in the success path of
> > isp_fwnodes_parse() -- can you check that?
>
> Where exactly? I noticed that if notifier->num_subdevs hits the limit the
> last node isn't put properly. I'll fix that. Is that what you meant?

I guess I'm confused. I see no put on the success path. Maybe it is
put somewhere out of the function where I did not look... is the
reference held while the driver is running

> > --- a/drivers/media/platform/omap3isp/isp.c
> > +++ b/drivers/media/platform/omap3isp/isp.c
> > @@ -2114,7 +2114,7 @@ static int isp_fwnode_parse(struct device *dev, struct fwnode_handle *fwn,
> > buscfg->bus.ccp2.lanecfg.data[0].pol =
> > vfwn.bus.mipi_csi1.lane_polarity[1];
> >
> > - dev_dbg(dev, "data lane %u polarity %u, pos %u\n", i,
> > + dev_dbg(dev, "data lane %u polarity %u, pos %u\n", 0,
>
> Why?

I was printing uninitialized / unused variable, which is a no-no (and
gcc complains). I guess I should do a separate patch.

> > buscfg->bus.ccp2.lanecfg.data[0].pol,
> > buscfg->bus.ccp2.lanecfg.data[0].pos);
> >
> > @@ -2162,10 +2162,64 @@ static int isp_fwnode_parse(struct device *dev, struct fwnode_handle *fwn,
> > return 0;
> > }
> >
> > +static int camera_subdev_parse(struct device *dev, struct v4l2_async_notifier *notifier,
> > + const char *key)
> > +{
> > + struct device_node *node;
> > + struct isp_async_subdev *isd;
> > +
> > + printk("Looking for %s\n", key);
> > +
> > + node = of_parse_phandle(dev->of_node, key, 0);
>
> There may be more than one flash associated with a sensor. Speaking of which
> --- how is it associated to the sensors?

Ok, more then one flash I can understand (will fix).

> One way to do this could be to simply move the flash property to the sensor
> OF node. We could have it here, too, if the flash was not associated with
> any sensor, but I doubt that will ever be needed.
>
> This really calls fork moving this part to the framework away from
> drivers.

The rest I don't get :-(. The flash is likely connected over i2c, so
it should not become child node of omap3isp.

And yes, I agree we want to move it into the framework. Lets agree on
how it should work and where to put it, I'll debug it here then move it...

> > + if (!node)
> > + return 0;
> > +
> > + printk("Having subdevice: %p\n", node);
> > +
> > + isd = devm_kzalloc(dev, sizeof(*isd), GFP_KERNEL);
> > + if (!isd)
> > + return -ENOMEM;
> > +
> > + notifier->subdevs[notifier->num_subdevs] = &isd->asd;
> > +
> > + isd->asd.match.of.node = node;
> > + if (!isd->asd.match.of.node) {
>
> You should check node here first.

Umm. I did, above. This can't happen, AFAICT.

> > + dev_warn(dev, "bad remote port parent\n");
> > + return -EIO;
> > + }
> > +
>
> And then assign it here.
>
> isd->asd.match.fwnode.fwn = of_fwnode_handle(node);
>
> > + isd->asd.match_type = V4L2_ASYNC_MATCH_OF;
>
> V4L2_ASYNC_MATCH_FWNODE, please.

Ok. Lets see if it still works after the changes :-)... it does, good.

> > +static int camera_subdevs_parse(struct device *dev, struct v4l2_async_notifier *notifier,
> > + int max)
> > +{
> > + int res = 0;
>
> No need to assign res here.

Ok.

Thanks and best regards,