[PATCHv3 1/6] drm/i915/histogram: Add support for histogram

[Murthy, Arun R]

> > > +static int intel_histogram_enable(struct intel_crtc *intel_crtc) {
> > > +	struct intel_display *display = to_intel_display(intel_crtc);
> > > +	struct intel_histogram *histogram = intel_crtc->histogram;
> > > +	int pipe = intel_crtc->pipe;
> > > +	u64 res;
> > > +	u32 gbandthreshold;
> > > +
> > > +	if (!histogram)
> > > +		return -EINVAL;
> > > +
> > > +	if (!histogram->can_enable)
> > > +		return -EINVAL;
> > > +
> > > +	if (histogram->enable)
> > > +		return 0;
> > > +
> > > +	/* Pipe Dithering should be enabled with GLOBAL_HIST */
> > > +	intel_histogram_enable_dithering(display, pipe);
> > > +
> > > +	 /* enable histogram, clear DPST_BIN reg and select TC function */
> > > +	intel_de_rmw(display, DPST_CTL(pipe),
> > > +		     DPST_CTL_BIN_REG_FUNC_SEL | DPST_CTL_IE_HIST_EN |
> > > +		     DPST_CTL_HIST_MODE |
> > > DPST_CTL_IE_TABLE_VALUE_FORMAT,
> > > +		     DPST_CTL_BIN_REG_FUNC_TC | DPST_CTL_IE_HIST_EN |
> > > +		     DPST_CTL_HIST_MODE_HSV |
> > > +		     DPST_CTL_IE_TABLE_VALUE_FORMAT_1INT_9FRAC);
> 
> Why 1.9 and not 2.8 ,
> Also should we be checking was the input type is before selecting mode,
> 
This tells the format to be used for image enhancement value in multiplicative mode. The algorithm will have to use this format.

Thanks and Regards,
Arun R Murthy
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