diff options
| -rw-r--r-- | drivers/staging/media/imx/TODO | 29 |
1 files changed, 7 insertions, 22 deletions
diff --git a/drivers/staging/media/imx/TODO b/drivers/staging/media/imx/TODO index 9eb7326f3fc6..aeeb15494a49 100644 --- a/drivers/staging/media/imx/TODO +++ b/drivers/staging/media/imx/TODO @@ -17,29 +17,15 @@ decided whether this feature is useful enough to make it generally available by exporting to v4l2-core. -- The OF graph is walked at probe time to form the list of fwnodes to - be passed to v4l2_async_notifier_register(), starting from the IPU - CSI ports. And after all async subdevices have been bound, - v4l2_fwnode_parse_link() is used to form the media links between - the entities discovered by walking the OF graph. +- After all async subdevices have been bound, v4l2_fwnode_parse_link() + is used to form the media links between the devices discovered in + the OF graph. While this approach allows support for arbitrary OF graphs, there are some assumptions for this to work: - 1. All port parent nodes reachable in the graph from the IPU CSI - ports bind to V4L2 async subdevice drivers. - - If a device has mixed-use ports such as video plus audio, the - endpoints from the audio ports are followed to devices that must - bind to V4L2 subdevice drivers, and not for example, to an ALSA - driver or a non-V4L2 media driver. If the device were bound to - such a driver, imx-media would never get an async completion - notification because the device fwnode was added to the async - list, but the driver does not interface with the V4L2 async - framework. - - 2. Every port reachable in the graph is treated as a media pad, - owned by the V4L2 subdevice that is bound to the port's parent. + 1. If a port owned by a device in the graph has endpoint nodes, the + port is treated as a media pad. This presents problems for devices that don't make this port = pad assumption. Examples are SMIAPP compatible cameras which define only @@ -54,9 +40,8 @@ possible long-term solution is to implement a subdev API that maps a port id to a media pad index. - 3. Every endpoint of a port reachable in the graph is treated as - a media link, between V4L2 subdevices that are bound to the - port parents of the local and remote endpoints. + 2. Every endpoint of a port owned by a device in the graph is treated + as a media link. Which means a port must not contain mixed-use endpoints, they must all refer to media links between V4L2 subdevices. |