[Intel-gfx] [PATCH 5/9] drm/display/dp: Add helper function to get DSC bpp prescision

[Kandpal, Suraj]

> 
> > Add helper to get the DSC bits_per_pixel precision for the DP sink.
> >
> > Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>

Wouldn't we also need to send this patch to dri-devel

Regards,
Suraj Kandpal
> > ---
> >  drivers/gpu/drm/display/drm_dp_helper.c | 27
> > +++++++++++++++++++++++++
> >  include/drm/display/drm_dp_helper.h     |  1 +
> >  2 files changed, 28 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
> > b/drivers/gpu/drm/display/drm_dp_helper.c
> > index e6a78fd32380..aa8ea36211de 100644
> > --- a/drivers/gpu/drm/display/drm_dp_helper.c
> > +++ b/drivers/gpu/drm/display/drm_dp_helper.c
> > @@ -2323,6 +2323,33 @@ int drm_dp_read_desc(struct drm_dp_aux *aux,
> > struct drm_dp_desc *desc,  }  EXPORT_SYMBOL(drm_dp_read_desc);
> >
> > +/**
> > + * drm_dp_dsc_sink_bpp_incr() - Get bits per pixel increment
> > + * @dsc_dpcd: DSC capabilities from DPCD
> > + *
> > + * Returns the bpp precision supported by the DP sink.
> > + */
> > +u8 drm_dp_dsc_sink_bpp_incr(const u8
> > +dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
> > +{
> > +	u8 bpp_increment_dpcd = dsc_dpcd[DP_DSC_BITS_PER_PIXEL_INC -
> > +DP_DSC_SUPPORT];
> > +
> > +	switch (bpp_increment_dpcd) {
> > +	case DP_DSC_BITS_PER_PIXEL_1_16:
> > +		return 16;
> > +	case DP_DSC_BITS_PER_PIXEL_1_8:
> > +		return 8;
> > +	case DP_DSC_BITS_PER_PIXEL_1_4:
> > +		return 4;
> > +	case DP_DSC_BITS_PER_PIXEL_1_2:
> > +		return 2;
> > +	case DP_DSC_BITS_PER_PIXEL_1_1:
> > +		return 1;
> 
> Shouldn't there be a default MISSING_CASE to throw a warning if its none of the
> above case Occurs in case a addition bit for step is added in dpcd going forward
> 
> Regards,
> Suraj Kandpal
> 
> > +	}
> > +
> > +	return 0;
> > +}
> > +EXPORT_SYMBOL(drm_dp_dsc_sink_bpp_incr);
> > +
> >  /**
> >   * drm_dp_dsc_sink_max_slice_count() - Get the max slice count
> >   * supported by the DSC sink.
> > diff --git a/include/drm/display/drm_dp_helper.h
> > b/include/drm/display/drm_dp_helper.h
> > index 86f24a759268..ba0514f0b032 100644
> > --- a/include/drm/display/drm_dp_helper.h
> > +++ b/include/drm/display/drm_dp_helper.h
> > @@ -164,6 +164,7 @@ drm_dp_is_branch(const u8
> > dpcd[DP_RECEIVER_CAP_SIZE])  }
> >
> >  /* DP/eDP DSC support */
> > +u8 drm_dp_dsc_sink_bpp_incr(const u8
> > +dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
> >  u8 drm_dp_dsc_sink_max_slice_count(const u8
> > dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
> >  				   bool is_edp);
> >  u8 drm_dp_dsc_sink_line_buf_depth(const u8
> > dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
> > --
> > 2.40.1