[PATCHv3 01/10] drm/crtc: Add histogram properties

[Murthy, Arun R]

> On Tue, Dec 10, 2024 at 08:42:36AM +0000, Murthy, Arun R wrote:
> > > On Mon, Dec 09, 2024 at 09:54:55PM +0530, Arun R Murthy wrote:
> > > > Add variables for histogram drm_property, its corrsponding
> > > > crtc_state variables and define the structure pointed by the blob property.
> > > >
> > > > struct drm_histogram and drm_iet defined in
> > > > include/uapi/drm/drm_mode.h
> > > >
> > > > The property HISTOGRAM_ENABLE allows user to enable/disable the
> > > > histogram feature in the hardware. Upon KMD enabling by writing to
> > > > the hardware registers, a histogram is generated. Histogram is
> > > > composed of 'n' bins with each bin being an integer(pixel count).
> > >
> > > Is it really a count of pixels that fall into one of the bins?
> > It's the statistics generated for each frame that is sent to the display and the
> value corresponds to 5 bit pixel depth.
> 
> Let me try it once more, but this is becoming tiresome. Please provide a
> description of the property good enough so that one can implement
> HISTOGRAM support for the VKMS driver. You don't have to provide Intel-
> specific details, but the description should be complete enough.
> "The number of pixels falling into each of the bins, sorted by luminosity, started
> from the brighest ones" might be an example of a good enough desription.
> Then one can add such functionality to other drivers. Just saying "statistics"
> doesn't give us anything.
> 
This is a hardware feature and hence for other drivers to add support for this
means that the hardware should have support for this.
Each bin consists of 5 bit pixel depth.
Example code of how to use this histogram and increase the contrast is GHE.

Thanks and Regards,
Arun R Murthy
--------------------