[PATCH 0/6] media: v4l2-ctrls: Add camera sensor location

From: Jacopo Mondi
Date: Fri Aug 16 2019 - 10:17:06 EST

after yesterday's RFC I'm now sending a proper v1 for inclusion.
Thanks Hans, Laurent and Sakari for the comments on the RFC.

I have expanded the documentation, finalized on an integer control to expose
the camera sensor location, and provided and helper in v4l2-fwnode to parse
the firmware property and register the associated control.

On the helper: right now only 'location' is parsed and the assoiated
V4L2_CID_CAMERA_SENSOR_LOCATION control registered. Ideally, I would have liked
to support more properties coming from firmware and exposed through controls,
- V4L2_CID_LINK_FREQ which corresponds to the 'link-frequencies' property is
never directly parsed for firmware and exposed as a control in any mainline
driver. The contrary is actually true: all drivers but smiapp register values
not coming from DT but hardcoded in the driver itself. smiapp parses the link
frequencies from DT but does not expose them directly. This makes me wonder
about the actual purpose of the property if nobody uses that.
Should drivers be moved to retrieve the property from firmware instead?
- V4L2_CID_PIXEL_RATE depends on the link frequencies, number of lanes and
configured image format. It seems better handled by drivers instead of in an
helper considering how many parameters are required to calculate it.

So the newly added function just parses and expose the camera location, which
makes me wonder if it's worth an helper at all. What other properties could be
parsed and registered as controls which I have missed?


Jacopo Mondi (6):
media: dt-bindings: Document 'location' property
media: v4l2-ctrl: Document V4L2_CID_LOCATION
media: v4l2-ctrls: Add support for V4L2_CID_LOCATION
media: v4l2-fwnode: Add helper to register controls from fw
media: i2c: ov5670: Register controls from firmware
media: i2c: ov13858: Register controls from firmware

.../bindings/media/video-interfaces.txt | 10 +++++
.../media/uapi/v4l/ext-ctrls-camera.rst | 34 ++++++++++++++++
drivers/media/i2c/ov13858.c | 8 ++++
drivers/media/i2c/ov5670.c | 7 ++++
drivers/media/v4l2-core/v4l2-ctrls.c | 2 +
drivers/media/v4l2-core/v4l2-fwnode.c | 40 +++++++++++++++++++
include/media/v4l2-fwnode.h | 29 ++++++++++++++
include/uapi/linux/v4l2-controls.h | 5 +++
8 files changed, 135 insertions(+)