Re: [PATCH v2 2/4] drm/komeda: Introduce komeda_color_manager/state

["james qian wang (Arm Technology China)" <james.qian.wang@arm.com>]

On Tue, Aug 13, 2019 at 09:51:08AM +0000, Mihail Atanassov wrote:
> Hi James,
> 
> On Tuesday, 13 August 2019 05:56:07 BST james qian wang (Arm Technology China) wrote:
> > Many komeda component support color management like layer and IPS, so
> > komeda_color_manager/state are introduced to manager gamma, csc and degamma
> > together for easily share it to multiple componpent.
> > 
> > And for komeda_color_manager which:
> > - convert drm 3d gamma lut to komeda specific gamma coeffs
> > - gamma table management and hide the HW difference for komeda-CORE
> > 
> > Signed-off-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
> > ---
> >  .../arm/display/komeda/komeda_color_mgmt.c    | 126 ++++++++++++++++++
> >  .../arm/display/komeda/komeda_color_mgmt.h    |  32 ++++-
> >  2 files changed, 156 insertions(+), 2 deletions(-)
> > 
> > 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..bf2388d641b9 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.c
> > @@ -4,7 +4,9 @@
> >   * Author: James.Qian.Wang <james.qian.wang@arm.com>
> >   *
> >   */
> > +#include <drm/drm_print.h>
> >  
> > +#include "malidp_utils.h"
> >  #include "komeda_color_mgmt.h"
> >  
> >  /* 10bit precision YUV2RGB matrix */
> > @@ -65,3 +67,127 @@ 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 struct gamma_curve_sector igamma_sector_tbl[] = {
> > +	{0, 64, 64},
> > +};
> > +
> > +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_igamma_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs)
> > +{
> > +	drm_lut_to_coeffs(lut_blob, coeffs,
> > +			  igamma_sector_tbl, ARRAY_SIZE(igamma_sector_tbl));
> > +}
> > +
> > +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));
> > +}
> > +
> > +void drm_ctm_to_coeffs(struct drm_property_blob *ctm_blob, u32 *coeffs)
> > +{
> > +	struct drm_color_ctm *ctm;
> > +	u32 i;
> > +
> > +	if (!ctm_blob)
> > +		return;
> > +
> > +	ctm = ctm_blob->data;
> > +
> > +	for (i = 0; i < KOMEDA_N_CTM_COEFFS; ++i) {
> > +		/* Convert from S31.32 to Q3.12. */
> > +		s64 v = ctm->matrix[i];
> > +
> > +		coeffs[i] = clamp_val(v, 1 - (1LL << 34), (1LL << 34) - 1) >> 20;
> CTM matrix values are S31.32, i.e. sign-magnitude, so clamp_val won't
> give you the right result for negative coeffs. See
> malidp_crtc_atomic_check_ctm for the sign-mag -> 2's complement
> conversion.

Thank you Mihail for pointing this out.

No matter our user or kernel all assume this s31.32 as 2's complement. 
we need to correct them both.

> > +	}
> > +}
> > +
> > +void komeda_color_duplicate_state(struct komeda_color_state *new,
> > +				  struct komeda_color_state *old)
> [bikeshed] not really a _duplicate_state if all it does is refcounts.
> kmemdup here and return a pointer (with ERR_PTR on fail), or memcpy if
> you want to keep the signature?

Yes, the dup mostly should return a new ptr from a old, the dup name here
is not accurate.
the reason is the color_state is not a separated structure but always
embedded into layer_state, but I want to make all color_state operation
into a func.
Do you have any suggestion ?

> > +{
> > +	new->igamma = komeda_coeffs_get(old->igamma);
> > +	new->fgamma = komeda_coeffs_get(old->fgamma);
> > +}
> > +
> > +void komeda_color_cleanup_state(struct komeda_color_state *color_st)
> > +{
> > +	komeda_coeffs_put(color_st->igamma);
> > +	komeda_coeffs_put(color_st->fgamma);
> > +}
> > +
> > +int komeda_color_validate(struct komeda_color_manager *mgr,
> > +			  struct komeda_color_state *st,
> > +			  struct drm_property_blob *igamma_blob,
> > +			  struct drm_property_blob *fgamma_blob)
> > +{
> > +	u32 coeffs[KOMEDA_N_GAMMA_COEFFS];
> > +
> > +	komeda_color_cleanup_state(st);
> > +
> > +	if (igamma_blob) {
> > +		drm_lut_to_igamma_coeffs(igamma_blob, coeffs);
> > +		st->igamma = komeda_coeffs_request(mgr->igamma_mgr, coeffs);
> > +		if (!st->igamma) {
> > +			DRM_DEBUG_ATOMIC("request igamma table failed.\n");
> > +			return -EBUSY;
> > +		}
> > +	}
> > +
> > +	if (fgamma_blob) {
> > +		drm_lut_to_fgamma_coeffs(fgamma_blob, coeffs);
> > +		st->fgamma = komeda_coeffs_request(mgr->fgamma_mgr, coeffs);
> > +		if (!st->fgamma) {
> > +			DRM_DEBUG_ATOMIC("request fgamma table failed.\n");
> > +			return -EBUSY;
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> > 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..41a96b3b540f 100644
> > --- a/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
> > +++ b/drivers/gpu/drm/arm/display/komeda/komeda_color_mgmt.h
> > @@ -4,14 +4,42 @@
> >   * Author: James.Qian.Wang <james.qian.wang@arm.com>
> >   *
> >   */
> > -
> >  #ifndef _KOMEDA_COLOR_MGMT_H_
> >  #define _KOMEDA_COLOR_MGMT_H_
> >  
> >  #include <drm/drm_color_mgmt.h>
> > +#include "komeda_coeffs.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)

> I don't see how the number of LUT entries has anything to do with the
> bit-precision of each entry.

Because our komeda color is 12-bit precison, and for 1 vs 1 loopup
table, we need BIT(12) entries.

Thank you
James

> > +#define KOMEDA_N_CTM_COEFFS		9
> > +
> > +struct komeda_color_manager {
> > +	struct komeda_coeffs_manager *igamma_mgr;
> > +	struct komeda_coeffs_manager *fgamma_mgr;
> > +	bool has_ctm;
> > +};
> > +
> > +struct komeda_color_state {
> > +	struct komeda_coeffs_table *igamma;
> > +	struct komeda_coeffs_table *fgamma;
> > +};
> > +
> > +void komeda_color_duplicate_state(struct komeda_color_state *new,
> > +				  struct komeda_color_state *old);
> > +void komeda_color_cleanup_state(struct komeda_color_state *color_st);
> > +int komeda_color_validate(struct komeda_color_manager *mgr,
> > +			  struct komeda_color_state *st,
> > +			  struct drm_property_blob *igamma_blob,
> > +			  struct drm_property_blob *fgamma_blob);
> > +
> > +void drm_lut_to_igamma_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs);
> > +void drm_lut_to_fgamma_coeffs(struct drm_property_blob *lut_blob, u32 *coeffs);
> > +void drm_ctm_to_coeffs(struct drm_property_blob *ctm_blob, u32 *coeffs);
> >  
> >  const s32 *komeda_select_yuv2rgb_coeffs(u32 color_encoding, u32 color_range);
> >  
> > -#endif
> > +#endif /*_KOMEDA_COLOR_MGMT_H_*/
> > 
> 
> BR,
> Mihail
> 
>