Hi Erling, On 03/08/2022 09:58, Erling Ljunggren wrote: > Add documentation for the new edid eeprom capability. > > Signed-off-by: Erling Ljunggren <hljunggr@xxxxxxxxx> > --- > Documentation/userspace-api/media/v4l/biblio.rst | 11 +++++++++++ > .../userspace-api/media/v4l/vidioc-querycap.rst | 7 +++++++ > .../userspace-api/media/videodev2.h.rst.exceptions | 1 + > 3 files changed, 19 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/biblio.rst b/Documentation/userspace-api/media/v4l/biblio.rst > index 9cd18c153d19..5cbe41877a63 100644 > --- a/Documentation/userspace-api/media/v4l/biblio.rst > +++ b/Documentation/userspace-api/media/v4l/biblio.rst > @@ -334,6 +334,17 @@ VESA DMT > > :author: Video Electronics Standards Association (http://www.vesa.org) > > +.. _vesaeddc: > + > +E-DDC > +==== > + > + > +:title: VESA Enhanced Display Data Channel (E-DDC) Standard > +:subtitle: Version 1.3 > + > +:author: Video Electronics Standards Association (http://www.vesa.org) > + > .. _vesaedid: > > EDID > diff --git a/Documentation/userspace-api/media/v4l/vidioc-querycap.rst b/Documentation/userspace-api/media/v4l/vidioc-querycap.rst > index 63e23f6f95ee..bdb530bd6816 100644 > --- a/Documentation/userspace-api/media/v4l/vidioc-querycap.rst > +++ b/Documentation/userspace-api/media/v4l/vidioc-querycap.rst > @@ -173,6 +173,13 @@ specification the ioctl returns an ``EINVAL`` error code. > interface. A video overlay device typically stores captured images > directly in the video memory of a graphics card, with hardware > clipping and scaling. > + * - ``V4L2_CAP_EDID_MEMORY`` > + - 0x00000008 > + - The device is a standalone EDID memory device. This is typically an eeprom > + that supports the VESA Enhanced Display Data Channel Standard. > + > + While an eeprom is the most common implementation, it can be something else > + as well, such as a microcontroller. Hence the generic name 'memory'. I realized that this is not just needed for inputs, but also for outputs. This is the case for an HDMI splitter that is connected to a computer via (typically) a serial port where you can use that to get/set the EDID for the input port and get the EDIDs for the output ports (i.e. the EDIDs from the connected displays). It's the same concept: a standalone EDID device. However, you are not talking directly to a memory device like an eeprom. So I think to keep things generic this capability should be renamed to just V4L2_CAP_EDID. The description should be updated as well since it is no longer just for inputs. And I think we can drop the references to 'memory'. It's really about hardware devices that store an EDID for a sink or read an EDID from a source. Patch 5 will have to be updated as well since for an output device this cap is associated with ENUM/S/G_OUTPUT. And for output S_EDID is not supported, of course. I'm working on a driver for an HDMI Splitter (CEC and EDID support), so this would come in very handy for that. Regards, Hans > * - ``V4L2_CAP_VBI_CAPTURE`` > - 0x00000010 > - The device supports the :ref:`Raw VBI Capture <raw-vbi>` > diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions > index 9cbb7a0c354a..12fa290828e7 100644 > --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions > +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions > @@ -185,6 +185,7 @@ replace define V4L2_CAP_META_OUTPUT device-capabilities > replace define V4L2_CAP_DEVICE_CAPS device-capabilities > replace define V4L2_CAP_TOUCH device-capabilities > replace define V4L2_CAP_IO_MC device-capabilities > +replace define V4L2_CAP_EDID_MEMORY device-capabilities > > # V4L2 pix flags > replace define V4L2_PIX_FMT_PRIV_MAGIC :c:type:`v4l2_pix_format`
