Re: [PATCH v4 2/4] drm/komeda: Add drm_lut_to_fgamma_coeffs()

[james qian wang (Arm Technology China)]

On Tue, Oct 15, 2019 at 08:29:52AM +0000, Brian Starkey wrote:
> Hi James,
> 
> On Tue, Oct 15, 2019 at 02:10:53AM +0000, james qian wang (Arm Technology China) wrote:
> > This function is used to convert drm 3dlut to komeda HW required 1d curve
> 
> This is a 1D LUT, not a 3D LUT
>

Thank you Brian will correct it in the next version.

James

> Cheers,
> -Brian
> 
> > coeffs values.
> > 
> > Signed-off-by: james qian wang (Arm Technology China) <james.qian.wang@xxxxxxx>
> > Reviewed-by: Mihail Atanassov <mihail.atanassov@xxxxxxx>
> > ---
> >  .../arm/display/komeda/komeda_color_mgmt.c    | 52 +++++++++++++++++++
> >  .../arm/display/komeda/komeda_color_mgmt.h    |  9 +++-
> >  2 files changed, 60 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
> > index 9d14a92dbb17..c180ce70c26c 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
> > @@ -65,3 +65,55 @@ const s32 *komeda_select_yuv2rgb_coeffs(u32 color_encoding, u32 color_range)
> >  
> >  	return coeffs;
> >  }
> > +
> > +struct gamma_curve_sector {
> > +	u32 boundary_start;
> > +	u32 num_of_segments;
> > +	u32 segment_width;
> > +};
> > +
> > +struct gamma_curve_segment {
> > +	u32 start;
> > +	u32 end;
> > +};
> > +
> > +static struct gamma_curve_sector sector_tbl[] = {
> > +	{ 0,    4,  4   },
> > +	{ 16,   4,  4   },
> > +	{ 32,   4,  8   },
> > +	{ 64,   4,  16  },
> > +	{ 128,  4,  32  },
> > +	{ 256,  4,  64  },
> > +	{ 512,  16, 32  },
> > +	{ 1024, 24, 128 },
> > +};
> > +
> > +static void
> > +drm_lut_to_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs,
> > +		  struct gamma_curve_sector *sector_tbl, u32 num_sectors)
> > +{
> > +	struct drm_color_lut *lut;
> > +	u32 i, j, in, num = 0;
> > +
> > +	if (!lut_blob)
> > +		return;
> > +
> > +	lut = lut_blob->data;
> > +
> > +	for (i = 0; i < num_sectors; i++) {
> > +		for (j = 0; j < sector_tbl[i].num_of_segments; j++) {
> > +			in = sector_tbl[i].boundary_start +
> > +			     j * sector_tbl[i].segment_width;
> > +
> > +			coeffs[num++] = drm_color_lut_extract(lut[in].red,
> > +						KOMEDA_COLOR_PRECISION);
> > +		}
> > +	}
> > +
> > +	coeffs[num] = BIT(KOMEDA_COLOR_PRECISION);
> > +}
> > +
> > +void drm_lut_to_fgamma_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs)
> > +{
> > +	drm_lut_to_coeffs(lut_blob, coeffs, sector_tbl, ARRAY_SIZE(sector_tbl));
> > +}
> > diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
> > index a2df218f58e7..08ab69281648 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
> > @@ -11,7 +11,14 @@
> >  #include <drm/drm_color_mgmt.h>
> >  
> >  #define KOMEDA_N_YUV2RGB_COEFFS		12
> > +#define KOMEDA_N_RGB2YUV_COEFFS		12
> > +#define KOMEDA_COLOR_PRECISION		12
> > +#define KOMEDA_N_GAMMA_COEFFS		65
> > +#define KOMEDA_COLOR_LUT_SIZE		BIT(KOMEDA_COLOR_PRECISION)
> > +#define KOMEDA_N_CTM_COEFFS		9
> > +
> > +void drm_lut_to_fgamma_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs);
> >  
> >  const s32 *komeda_select_yuv2rgb_coeffs(u32 color_encoding, u32 color_range);
> >  
> > -#endif
> > +#endif /*_KOMEDA_COLOR_MGMT_H_*/
> > -- 
> > 2.20.1
> >