On 19/05/2020 12:08, Sakari Ailus wrote: > On Tue, May 19, 2020 at 11:28:48AM +0200, Hans Verkuil wrote: >> On 19/05/2020 11:17, Sakari Ailus wrote: >>> Hi Hans, >>> >>> On Tue, May 19, 2020 at 11:05:31AM +0200, Hans Verkuil wrote: >>>> On 19/05/2020 10:50, Sakari Ailus wrote: >>>>> The media bus codes to be used on serial busses are documented but there >>>>> was no reference from CSI-2 documentation. Add that now. >>>>> >>>>> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> >>>>> --- >>>>> Documentation/driver-api/media/csi2.rst | 7 +++++++ >>>>> 1 file changed, 7 insertions(+) >>>>> >>>>> diff --git a/Documentation/driver-api/media/csi2.rst b/Documentation/driver-api/media/csi2.rst >>>>> index da8b356389f0..1653a51d2a6e 100644 >>>>> --- a/Documentation/driver-api/media/csi2.rst >>>>> +++ b/Documentation/driver-api/media/csi2.rst >>>>> @@ -10,6 +10,13 @@ the host SoC. It is defined by the `MIPI alliance`_. >>>>> >>>>> .. _`MIPI alliance`: http://www.mipi.org/ >>>>> >>>>> +Media bus formats >>>>> +----------------- >>>>> + >>>>> +Always use the media bus pixel code that describes a parallel format that >>>>> +transfers a sample on a single clock cycle. See :ref:`v4l2-mbus-format` for more >>>> >>>> How about: "transfers the pixel data as a single sample in one clock cycle" >>> >>> The text is from mbus format documentation. Note that this might not be >>> pixel data; it may be metadata as well. >> >> My problem with 'a sample' is that all parallel media bus formats transfer 'a sample' >> in a single clock cycle. It is not clearly defined what 'a sample' is. >> >> Either the text needs to be improved, or an example should be added here as well >> since an example clarifies what is meant. >> >>> >>>> >>>> Possibly with an example: "So use e.g. MEDIA_BUS_FMT_SBGGR10_1X10 instead of >>>> MEDIA_BUS_FMT_SBGGR10_2X8_PADHI_BE." >>> >>> There's an example in mbus format documentation. I'm fine adding one here, >>> too, but the purpose of this bit is to mainly refer to mbus format >>> documentation. Mbus format documentation uses MEDIA_BUS_FMT_BGR888_1X24 and >>> MEDIA_BUS_FMT_BGR888_3X8 as the example. >>> >> >> Ah, I see. But then the reference to v4l2-mbus-format is confusing, I'd >> change that to v4l2-mbus-pixelcode. That's where the example is. > > Ah, that's a better label indeed. I'll use that. With this, do you prefer > having the example here as well? > Rather than duplicating text, perhaps it is better to just refer to the v4l2-mbus-pixelcode section: +Media bus formats +----------------- + +See :ref:`v4l2-mbus-pixelcode` for details on which media bus formats should +be used for CSI-2 interfaces. Regards, Hans
