Hi Kieran, On Wed, Jun 06, 2018 at 02:51:49PM +0100, Kieran Bingham wrote: > Hi Jacopo, > > On 06/06/18 14:22, Jacopo Mondi wrote: > > Add initial support for media controller framework to the renesas-ceu driver. > > > > Adding media-controller support allows to operate sensors that expose advanced > > functionalities through the v4l2-subdev APIs. > > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> > > --- > > Hello, > > I'm in the process of adding support to a sensor driver that exposes advanced > > functionalities through the v4l2-subdev APIs. > > > > In order to operate on it, I had to add initial media-controller support to the > > host driver (renesas-ceu) to have the subdevice video nodes properly created. > > > > The current implementation allows to create and operate on the media graph, but > > the result is a lot of #ifdef in the driver code I don't see in any other > > mainline platform driver. > > I thought I saw a patch fly by which removed the need for #ifdef > MEDIA_CONTROLLER by allowing the mdev to exist and be NULL. > well, it's not that much about the mdev being NULL, it's that many operations are implemented differently when using mc. Eg. set_fmt does not call the subdev operations but instead relies on userspace configuring it on the 'next' subdevice, if I got the whole thing right. This calls for a compile time handling of the differences (using the pre-processor #idefs) or a runtime one, where different sets of operations can be registered depending on a parameter, like the matched compatible string (like VIN is doing at the moment). I fear I'm mixing apples and pears here. > However I can't find that now, so maybe I was confused by something else - and I > see that in the latest RequestAPI series, [0], [1], non-mc drivers are getting > MC support out of necessity and this is wrapped in #ifdefs. > > So I think for the moment, it's fine. Thanks for looking into this. For now, the patch stays in RFC, the CEU is a very simple device, and would not benefit that much from mc support except for my hacking activities. Thanks j > > [0] https://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg132623.html > [1] https://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg132634.html > > -- > Kieran > > > > As there are more media-controller specificities to be supported (eg. set_fmt > > that should not call into the subdev operations etc) before going too far I > > decided to send this out to collect suggestions. > > > > What is the best way to add media-controller support to a non-mc driver? > > > > Ideally I would like this to continue working with all sensor drivers, and thus > > I see a few ways of doing this: > > > > - Keep using #ifdef CONFIG_MEDIA_CONTROLLER, but I don't see it in any other > > driver in mainline > > - Add a media-controller compatible string, and decide at runtime if we should > > use media-controller or not (similar to what VIN driver does) > > - Make the driver media controller only, but I fear 'old-style' sensor driver > > won't be usable anymore with this new version. > > > > Any pointer/opinion is welcome. > > > > Thanks > > j > > --- > > drivers/media/platform/renesas-ceu.c | 111 +++++++++++++++++++++++++++++++++++ > > 1 file changed, 111 insertions(+) > > > > diff --git a/drivers/media/platform/renesas-ceu.c b/drivers/media/platform/renesas-ceu.c > > index 46b0639..5911f097 100644 > > --- a/drivers/media/platform/renesas-ceu.c > > +++ b/drivers/media/platform/renesas-ceu.c > > @@ -39,6 +39,7 @@ > > #include <media/v4l2-fwnode.h> > > #include <media/v4l2-image-sizes.h> > > #include <media/v4l2-ioctl.h> > > +#include <media/v4l2-mc.h> > > #include <media/v4l2-mediabus.h> > > #include <media/videobuf2-dma-contig.h> > > > > @@ -158,6 +159,9 @@ struct ceu_subdev { > > /* per-subdevice mbus configuration options */ > > unsigned int mbus_flags; > > struct ceu_mbus_fmt mbus_fmt; > > +#ifdef CONFIG_MEDIA_CONTROLLER > > + int source_pad; > > +#endif > > }; > > > > static struct ceu_subdev *to_ceu_subdev(struct v4l2_async_subdev *asd) > > @@ -173,6 +177,11 @@ struct ceu_device { > > struct video_device vdev; > > struct v4l2_device v4l2_dev; > > > > +#ifdef CONFIG_MEDIA_CONTROLLER > > + struct media_device mdev; > > + struct media_pad pad; > > +#endif > > + > > /* subdevices descriptors */ > > struct ceu_subdev *subdevs; > > /* the subdevice currently in use */ > > @@ -1381,6 +1390,60 @@ static void ceu_vdev_release(struct video_device *vdev) > > kfree(ceudev); > > } > > > > +#ifdef CONFIG_MEDIA_CONTROLLER > > +static int ceu_find_pad(struct v4l2_subdev *sd, int direction) > > +{ > > + unsigned int pad; > > + > > + if (sd->entity.num_pads <= 1) > > + return 0; > > + > > + for (pad = 0; pad < sd->entity.num_pads; pad++) > > + if (sd->entity.pads[pad].flags & direction) > > + return pad; > > + > > + return -EINVAL; > > +} > > + > > +static int ceu_notify_complete_mc(struct ceu_device *ceudev) > > +{ > > + struct video_device *vdev = &ceudev->vdev; > > + struct media_entity *source; > > + struct media_entity *sink; > > + > > + unsigned int i; > > + int ret; > > + > > + ret = media_device_register(&ceudev->mdev); > > + if (ret) { > > + v4l2_err(vdev->v4l2_dev, > > + "media_device_register failed : %d\n", ret); > > + return ret; > > + } > > + > > + ret = v4l2_device_register_subdev_nodes(&ceudev->v4l2_dev); > > + if (ret) > > + return ret; > > + > > + /* Link subdev's first available source pad to CEU sink one. */ > > + for (i = 0; i < ceudev->num_sd; i++) { > > + int source_pad = ceudev->subdevs[i].source_pad; > > + > > + if (source_pad < 0) > > + continue; > > + > > + source = &ceudev->subdevs[i].v4l2_sd->entity; > > + sink = &vdev->entity; > > + > > + ret = media_create_pad_link(source, source_pad, sink, 0, 0); > > + if (ret) > > + return ret; > > + } > > + > > + return 0; > > +} > > +#endif > > + > > static int ceu_notify_bound(struct v4l2_async_notifier *notifier, > > struct v4l2_subdev *v4l2_sd, > > struct v4l2_async_subdev *asd) > > @@ -1392,6 +1455,11 @@ static int ceu_notify_bound(struct v4l2_async_notifier *notifier, > > ceu_sd->v4l2_sd = v4l2_sd; > > ceudev->num_sd++; > > > > +#ifdef CONFIG_MEDIA_CONTROLLER > > + /* Cache the entity source pad for later link creation. */ > > + ceu_sd->source_pad = ceu_find_pad(v4l2_sd, MEDIA_PAD_FL_SOURCE); > > +#endif > > + > > return 0; > > } > > > > @@ -1459,6 +1527,14 @@ static int ceu_notify_complete(struct v4l2_async_notifier *notifier) > > return ret; > > } > > > > +#ifdef CONFIG_MEDIA_CONTROLLER > > + ret = ceu_notify_complete_mc(ceudev); > > + if (ret) { > > + video_unregister_device(&ceudev->vdev); > > + return ret; > > + } > > +#endif > > + > > return 0; > > } > > > > @@ -1467,6 +1543,12 @@ static const struct v4l2_async_notifier_operations ceu_notify_ops = { > > .complete = ceu_notify_complete, > > }; > > > > +#ifdef CONFIG_MEDIA_CONTROLLER > > +static const struct media_device_ops ceu_media_ops = { > > + .link_notify = v4l2_pipeline_link_notify, > > +}; > > +#endif > > + > > /* > > * ceu_init_async_subdevs() - Initialize CEU subdevices and async_subdevs in > > * ceu device. Both DT and platform data parsing use > > @@ -1631,6 +1713,9 @@ static int ceu_probe(struct platform_device *pdev) > > struct device *dev = &pdev->dev; > > const struct ceu_data *ceu_data; > > struct ceu_device *ceudev; > > +#ifdef CONFIG_MEDIA_CONTROLLER > > + struct media_device *mdev; > > +#endif > > struct resource *res; > > unsigned int irq; > > int num_subdevs; > > @@ -1670,6 +1755,24 @@ static int ceu_probe(struct platform_device *pdev) > > > > pm_runtime_enable(dev); > > > > +#ifdef CONFIG_MEDIA_CONTROLLER > > + mdev = &ceudev->mdev; > > + mdev->dev = dev; > > + mdev->ops = &ceu_media_ops; > > + strlcpy(mdev->driver_name, KBUILD_MODNAME, sizeof(mdev->driver_name)); > > + strlcpy(mdev->model, KBUILD_MODNAME, sizeof(mdev->model)); > > + snprintf(mdev->bus_info, sizeof(mdev->bus_info), "platform:%s", > > + dev_name(mdev->dev)); > > + > > + media_device_init(mdev); > > + ceudev->v4l2_dev.mdev = mdev; > > + > > + ceudev->pad.flags = MEDIA_PAD_FL_SINK; > > + ret = media_entity_pads_init(&ceudev->vdev.entity, 1, &ceudev->pad); > > + if (ret) > > + goto error_pm_disable; > > +#endif > > + > > ret = v4l2_device_register(dev, &ceudev->v4l2_dev); > > if (ret) > > goto error_pm_disable; > > @@ -1709,6 +1812,9 @@ static int ceu_probe(struct platform_device *pdev) > > v4l2_device_unregister(&ceudev->v4l2_dev); > > error_pm_disable: > > pm_runtime_disable(dev); > > +#ifdef CONFIG_MEDIA_CONTROLLER > > + media_device_cleanup(&ceudev->mdev); > > +#endif > > error_free_ceudev: > > kfree(ceudev); > > > > @@ -1723,6 +1829,11 @@ static int ceu_remove(struct platform_device *pdev) > > > > v4l2_async_notifier_unregister(&ceudev->notifier); > > > > +#ifdef CONFIG_MEDIA_CONTROLLER > > + media_device_cleanup(&ceudev->mdev); > > + media_device_unregister(&ceudev->mdev); > > +#endif > > + > > v4l2_device_unregister(&ceudev->v4l2_dev); > > > > video_unregister_device(&ceudev->vdev); > > -- > > 2.7.4 > > >
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