target/linux/bcm27xx/patches-5.15/950-0771-media-v4l2-async-Create-links-during-v4l2_async_matc.patch

   1 From 3f32e8b803061cf04a1fe31a3070e46fd0d379e8 Mon Sep 17 00:00:00 2001
   2 From: Daniel Scally <djrscally@gmail.com>
   3 Date: Wed, 2 Mar 2022 22:03:04 +0000
   4 Subject: [PATCH] media: v4l2-async: Create links during
   5  v4l2_async_match_notify()
   6
   7 Upon an async fwnode match, there's some typical behaviour that the
   8 notifier and matching subdev will want to do. For example, a notifier
   9 representing a sensor matching to an async subdev representing its
  10 VCM will want to create an ancillary link to expose that relationship
  11 to userspace.
  12
  13 To avoid lots of code in individual drivers, try to build these links
  14 within v4l2 core.
  15
  16 Signed-off-by: Daniel Scally <djrscally@gmail.com>
  17 ---
  18  drivers/media/v4l2-core/v4l2-async.c | 31 ++++++++++++++++++++++++++++
  19  1 file changed, 31 insertions(+)
  20
  21 --- a/drivers/media/v4l2-core/v4l2-async.c
  22 +++ b/drivers/media/v4l2-core/v4l2-async.c
  23 @@ -275,6 +275,24 @@ v4l2_async_notifier_try_complete(struct
  24  static int
  25  v4l2_async_notifier_try_all_subdevs(struct v4l2_async_notifier *notifier);
  26
  27 +static int v4l2_async_create_ancillary_links(struct v4l2_async_notifier *n,
  28 +                                            struct v4l2_subdev *sd)
  29 +{
  30 +       struct media_link *link = NULL;
  31 +
  32 +#if IS_ENABLED(CONFIG_MEDIA_CONTROLLER)
  33 +
  34 +       if (sd->entity.function != MEDIA_ENT_F_LENS &&
  35 +           sd->entity.function != MEDIA_ENT_F_FLASH)
  36 +               return 0;
  37 +
  38 +       link = media_create_ancillary_link(&n->sd->entity, &sd->entity);
  39 +
  40 +#endif
  41 +
  42 +       return IS_ERR(link) ? PTR_ERR(link) : 0;
  43 +}
  44 +
  45  static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier,
  46                                    struct v4l2_device *v4l2_dev,
  47                                    struct v4l2_subdev *sd,
  48 @@ -292,6 +310,19 @@ static int v4l2_async_match_notify(struc
  49                 v4l2_device_unregister_subdev(sd);
  50                 return ret;
  51         }
  52 +
  53 +       /*
  54 +        * Depending of the function of the entities involved, we may want to
  55 +        * create links between them (for example between a sensor and its lens
  56 +        * or between a sensor's source pad and the connected device's sink
  57 +        * pad).
  58 +        */
  59 +       ret = v4l2_async_create_ancillary_links(notifier, sd);
  60 +       if (ret) {
  61 +               v4l2_async_notifier_call_unbind(notifier, sd, asd);
  62 +               v4l2_device_unregister_subdev(sd);
  63 +               return ret;
  64 +       }
  65
  66         /* Remove from the waiting list */
  67         list_del(&asd->list);