[media] v4l2-subdev: add (un)register internal ops

Some subdevs need to call into the board code after they are registered
and have a valid struct v4l2_device pointer. The s_config op was abused
for this, but now that it is removed we need a cleaner way of solving this.

So this patch adds a struct with internal ops that the v4l2 core can call.

Currently only two ops exist: register and unregister. Subdevs can implement
these to call the board code and pass it the v4l2_device pointer, which the
board code can then use to get access to the struct that embeds the
v4l2_device.

It is expected that in the future open and close ops will also be added.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 42fbe462031..daf1e57d9b2 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -411,6 +411,21 @@ struct v4l2_subdev_ops {
         const struct v4l2_subdev_sensor_ops     *sensor;
 };
 
+/*
+ * Internal ops. Never call this from drivers, only the v4l2 framework can call
+ * these ops.
+ *
+ * registered: called when this subdev is registered. When called the v4l2_dev
+ *      field is set to the correct v4l2_device.
+ *
+ * unregistered: called when this subdev is unregistered. When called the
+ *      v4l2_dev field is still set to the correct v4l2_device.
+ */
+struct v4l2_subdev_internal_ops {
+        int (*registered)(struct v4l2_subdev *sd);
+        void (*unregistered)(struct v4l2_subdev *sd);
+};
+
 #define V4L2_SUBDEV_NAME_SIZE 32
 
 /* Set this flag if this subdev is a i2c device. */
@@ -427,6 +442,8 @@ struct v4l2_subdev {
         u32 flags;
         struct v4l2_device *v4l2_dev;
         const struct v4l2_subdev_ops *ops;
+        /* Never call these internal ops from within a driver! */
+        const struct v4l2_subdev_internal_ops *internal_ops;
         /* The control handler of this subdev. May be NULL. */
         struct v4l2_ctrl_handler *ctrl_handler;
         /* name must be unique */