[PATCH v4 2/5] drm/i915/display: Compute the scaler filter coefficients
Srikanth V, NagaVenkata
nagavenkata.srikanth.v at intel.com
Wed Oct 30 04:50:10 UTC 2024
Looks good to me.
Reviewed-by: Naga Venkata Srikanth V <nagavenkata.srikanth.v at intel.com>
> -----Original Message-----
> From: Garg, Nemesa <nemesa.garg at intel.com>
> Sent: Thursday, October 24, 2024 2:41 PM
> To: Srikanth V, NagaVenkata <nagavenkata.srikanth.v at intel.com>; intel-
> gfx at lists.freedesktop.org
> Subject: RE: [PATCH v4 2/5] drm/i915/display: Compute the scaler filter
> coefficients
>
>
>
> > -----Original Message-----
> > From: Srikanth V, NagaVenkata <nagavenkata.srikanth.v at intel.com>
> > Sent: Thursday, October 24, 2024 12:41 PM
> > To: Garg, Nemesa <nemesa.garg at intel.com>;
> > intel-gfx at lists.freedesktop.org
> > Cc: Garg, Nemesa <nemesa.garg at intel.com>
> > Subject: RE: [PATCH v4 2/5] drm/i915/display: Compute the scaler
> > filter coefficients
> >
> >
> >
> > > -----Original Message-----
> > > From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf
> > > Of Nemesa Garg
> > > Sent: Monday, October 14, 2024 4:43 PM
> > > To: intel-gfx at lists.freedesktop.org
> > > Cc: Garg, Nemesa <nemesa.garg at intel.com>
> > > Subject: [PATCH v4 2/5] drm/i915/display: Compute the scaler filter
> > > coefficients
> > >
> > > The sharpness property requires the use of one of the scaler so need
> > > to set the sharpness scaler coefficient values.
> > > These values are based on experiments and vary for different tap
> > > value/win size. These values are normalized by taking the sum of all
> > > values and then dividing each value with a sum.
> > >
> > > v2: Fix ifndef header naming issue reported by kernel test robot
> > > v3: Rename file name[Arun]
> > > Replace array size number with macro[Arun]
> > > v4: Correct the register format[Jani]
> > > Add brief comment and expalin about file[Jani]
> > > Remove coefficient value from crtc_state[Jani]
> > >
> > > Signed-off-by: Nemesa Garg <nemesa.garg at intel.com>
> > > ---
> > > drivers/gpu/drm/i915/Makefile | 1 +
> > > drivers/gpu/drm/i915/display/intel_casf.c | 131 ++++++++++++++++++
> > > drivers/gpu/drm/i915/display/intel_casf.h | 16 +++
> > > .../gpu/drm/i915/display/intel_casf_regs.h | 19 +++
> > > drivers/gpu/drm/i915/display/intel_display.c | 3 +
> > > .../drm/i915/display/intel_display_types.h | 14 ++
> > > drivers/gpu/drm/i915/i915_reg.h | 2 +
> > > drivers/gpu/drm/xe/Makefile | 1 +
> > > 8 files changed, 187 insertions(+)
> > > create mode 100644 drivers/gpu/drm/i915/display/intel_casf.c
> > > create mode 100644 drivers/gpu/drm/i915/display/intel_casf.h
> > > create mode 100644 drivers/gpu/drm/i915/display/intel_casf_regs.h
> > >
> > > diff --git a/drivers/gpu/drm/i915/Makefile
> > > b/drivers/gpu/drm/i915/Makefile index c63fa2133ccb..ba3c33ca3149
> > > 100644
> > > --- a/drivers/gpu/drm/i915/Makefile
> > > +++ b/drivers/gpu/drm/i915/Makefile
> > > @@ -280,6 +280,7 @@ i915-y += \
> > > display/intel_pmdemand.o \
> > > display/intel_psr.o \
> > > display/intel_quirks.o \
> > > + display/intel_casf.o \
> > > display/intel_sprite.o \
> > > display/intel_sprite_uapi.o \
> > > display/intel_tc.o \
> > > diff --git a/drivers/gpu/drm/i915/display/intel_casf.c
> > > b/drivers/gpu/drm/i915/display/intel_casf.c
> > > new file mode 100644
> > > index 000000000000..75c1ae37ae1e
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/i915/display/intel_casf.c
> > > @@ -0,0 +1,131 @@
> > > +// SPDX-License-Identifier: MIT
> > > +/*
> > > + * Copyright (c) 2024 Intel Corporation
> > > + *
> > > + */
> > > +#include "i915_reg.h"
> > > +#include "intel_de.h"
> > > +#include "intel_display_types.h"
> > > +#include "intel_casf.h"
> > > +#include "intel_casf_regs.h"
> > > +#include "skl_scaler.h"
> > > +
> > > +#define FILTER_COEFF_0_125 125
> > > +#define FILTER_COEFF_0_25 250
> > > +#define FILTER_COEFF_0_5 500
> > > +#define FILTER_COEFF_1_0 1000
> > > +#define FILTER_COEFF_0_0 0
> > > +#define SET_POSITIVE_SIGN(x) ((x) & (~SIGN))
> > > +
> > > +/**
> > > + * DOC: Content Adaptive Sharpness Filter (CASF)
> > > + *
> > > + * From LNL onwards the display engine based adaptive
> > > + * sharpening filter is supported. This helps in
> > > + * improving the image quality. The display hardware
> > > + * uses one of the pipe scaler for implementing casf.
> > > + * It works on a region of pixels depending on the
> > > + * tap size. The coefficients are used to generate an
> > > + * alpha value which is used to blend the sharpened image
> > > + * to original image.
> > > + */
> > > +
> > > +const u16 filtercoeff_1[] = {FILTER_COEFF_0_0, FILTER_COEFF_0_0,
> > > +FILTER_COEFF_0_5, FILTER_COEFF_1_0, FILTER_COEFF_0_5,
> > > FILTER_COEFF_0_0,
> > > +FILTER_COEFF_0_0};
> > > +
> > > +const u16 filtercoeff_2[] = {FILTER_COEFF_0_0, FILTER_COEFF_0_25,
> > > +FILTER_COEFF_0_5, FILTER_COEFF_1_0, FILTER_COEFF_0_5,
> > > +FILTER_COEFF_0_25, FILTER_COEFF_0_0};
> > > +
> > > +const u16 filtercoeff_3[] = {FILTER_COEFF_0_125, FILTER_COEFF_0_25,
> > > +FILTER_COEFF_0_5, FILTER_COEFF_1_0, FILTER_COEFF_0_5,
> > > +FILTER_COEFF_0_25, FILTER_COEFF_0_125};
> > > +
> > > +static int casf_coef_tap(int i)
> > > +{
> > > + return i % 7;
> > > +}
> > > +
> > > +static u16 casf_coef(struct intel_crtc_state *crtc_state, int t) {
> > > + struct scaler_filter_coeff value;
> > > + u16 coeff;
> > > +
> > > + value = crtc_state->hw.casf_params.coeff[t];
> > > + coeff = SET_POSITIVE_SIGN(0) | EXPONENT(value.exp) |
> > > +MANTISSA(value.mantissa);
> > > +
> > > + return coeff;
> > > +}
> > > +
> > > +void intel_casf_enable(struct intel_crtc_state *crtc_state) {
> > > + struct intel_display *display = to_intel_display(crtc_state);
> > > + struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > > + int id = crtc_state->scaler_state.scaler_id;
> > > + int i;
> > > +
> > > + intel_de_write_fw(display, GLK_PS_COEF_INDEX_SET(crtc->pipe, id,
> > > 0),
> > > + PS_COEF_INDEX_AUTO_INC);
> > > +
> > > + intel_de_write_fw(display, GLK_PS_COEF_INDEX_SET(crtc->pipe, id,
> > > 1),
> > > + PS_COEF_INDEX_AUTO_INC);
> > > +
> > > + for (i = 0; i < 17 * 7; i += 2) {
> > > + u32 tmp;
> > > + int t;
> > > +
> > > + t = casf_coef_tap(i);
> > > + tmp = casf_coef(crtc_state, t);
> > > +
> > > + t = casf_coef_tap(i + 1);
> > > + tmp |= casf_coef(crtc_state, t) << 16;
> > > +
> > > + intel_de_write_fw(display, GLK_PS_COEF_DATA_SET(crtc-
> > > >pipe, id, 0),
> > > + tmp);
> > > + intel_de_write_fw(display, GLK_PS_COEF_DATA_SET(crtc-
> > > >pipe, id, 1),
> > > + tmp);
> > > + }
> > > +}
> > > +
> > > +static void convert_sharpness_coef_binary(struct scaler_filter_coeff
> *coeff,
> > > + u16 coefficient)
> > > +{
> > > + if (coefficient < 25) {
> > > + coeff->mantissa = (coefficient * 2048) / 100;
> > > + coeff->exp = 3;
> > > + } else if (coefficient < 50) {
> > > + coeff->mantissa = (coefficient * 1024) / 100;
> > > + coeff->exp = 2;
> > > + } else if (coefficient < 100) {
> > > + coeff->mantissa = (coefficient * 512) / 100;
> > > + coeff->exp = 1;
> > > + } else {
> > > + coeff->mantissa = (coefficient * 256) / 100;
> > > + coeff->exp = 0;
> > > + }
> > > +}
> > > +
> > > +static void intel_casf_coeff(struct intel_crtc_state *crtc_state) {
> > > + const u16 *filtercoeff;
> > > + u16 filter_coeff[SCALER_FILTER_NUM_TAPS];
> > > + u16 sumcoeff = 0;
> > > + u8 i;
> > > +
> > > + if (crtc_state->hw.casf_params.win_size == 0)
> > > + filtercoeff = filtercoeff_1;
> > > + else if (crtc_state->hw.casf_params.win_size == 1)
> > > + filtercoeff = filtercoeff_2;
> > > + else
> > > + filtercoeff = filtercoeff_3;
> > > +
> > > + for (i = 0; i < SCALER_FILTER_NUM_TAPS; i++)
> > > + sumcoeff += *(filtercoeff + i);
> >
> > filtercoeff[i] instead of *(filtercoeff + i)
> >
> > > +
> > > + for (i = 0; i < SCALER_FILTER_NUM_TAPS; i++) {
> > > + filter_coeff[i] = (*(filtercoeff + i) * 100 / sumcoeff);
> >
> > Just by multiplying by 100, we are losing precision. Multiply by 10000
> > to preserve the precision.
> > For e.g filtercoeff of 0.125 is stored as 125.
> >
> > Ideal case using double:
> > 0.125/2 -> 0.0625
> > 0.0625 converted to mantissa 0.0625*2048 -> 128
> >
> > 125*100/2000 -> 6
> > 6 converted to mantissa 6*2048/100 -> 122
> >
> > If we multiply by 10000
> > 125*10000/2000 -> 625
> > 625 converted to mantissa 625*2048/10000 -> 128
> >
> If we are considering the first coefficient set then we can either have 0/2 or
> 0.5/2 or 1/2 so in this case:
> Using double:
> 0.5/ 2.0 = 0.25 * 1024.0 = 256
> 1/2 = 0.5 = 0.5 * 1024 = 512
> Using integer:
> 500/2000 = 0.25 *100 = 25 * 1024 = 25600 /100 = 256
> 1000/2000 = 0.5 * 100 = 50 * 1024 = 51200 / 100 = 512
>
> So for different coefficient set, sumcoeff will change ie 2500 and 2750 , so
> multiplying with 100 also precision will be there.
>
> Regards,
> Nemesa
> > > + convert_sharpness_coef_binary(&crtc_state-
> > > >hw.casf_params.coeff[i],
> > > + filter_coeff[i]);
> > > + }
> > > +}
> > > +
> > > +void intel_casf_scaler_compute_config(struct intel_crtc_state
> > > +*crtc_state) {
> > > + intel_casf_coeff(crtc_state);
> > > +}
> > > diff --git a/drivers/gpu/drm/i915/display/intel_casf.h
> > > b/drivers/gpu/drm/i915/display/intel_casf.h
> > > new file mode 100644
> > > index 000000000000..8e0b67a2fd99
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/i915/display/intel_casf.h
> > > @@ -0,0 +1,16 @@
> > > +/* SPDX-License-Identifier: MIT */
> > > +/*
> > > + * Copyright (c) 2024 Intel Corporation */
> > > +
> > > +#ifndef __INTEL_CASF_H__
> > > +#define __INTEL_CASF_H__
> > > +
> > > +#include <linux/types.h>
> > > +
> > > +struct intel_crtc_state;
> > > +
> > > +void intel_casf_enable(struct intel_crtc_state *crtc_state); void
> > > +intel_casf_scaler_compute_config(struct intel_crtc_state
> > > +*crtc_state);
> > > +
> > > +#endif /* __INTEL_CASF_H__ */
> > > diff --git a/drivers/gpu/drm/i915/display/intel_casf_regs.h
> > > b/drivers/gpu/drm/i915/display/intel_casf_regs.h
> > > new file mode 100644
> > > index 000000000000..0b3fcdb22c0c
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/i915/display/intel_casf_regs.h
> > > @@ -0,0 +1,19 @@
> > > +/* SPDX-License-Identifier: MIT */
> > > +/*
> > > + * Copyright (c) 2024 Intel Corporation */
> > > +
> > > +#ifndef __INTEL_CASF_REGS_H__
> > > +#define __INTEL_CASF_REGS_H__
> > > +
> > > +#include "intel_display_reg_defs.h"
> > > +
> > > +/* Scaler Coefficient structure */
> > > +#define SIGN REG_BIT(15)
> > > +#define EXPONENT_MASK REG_GENMASK(13, 12)
> > > +#define EXPONENT(x)
> > REG_FIELD_PREP(EXPONENT_MASK,
> > > (x))
> > > +#define MANTISSA_MASK REG_GENMASK(11, 3)
> > > +#define MANTISSA(x)
> REG_FIELD_PREP(MANTISSA_MASK,
> > > (x))
> > > +
> > > +#endif /* __INTEL_CASF_REGS__ */
> > > +
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > index b4ef4d59da1a..224fd0c84f18 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -112,6 +112,7 @@
> > > #include "intel_psr.h"
> > > #include "intel_psr_regs.h"
> > > #include "intel_sdvo.h"
> > > +#include "intel_casf.h"
> > > #include "intel_snps_phy.h"
> > > #include "intel_tc.h"
> > > #include "intel_tdf.h"
> > > @@ -5917,6 +5918,8 @@ static int intel_atomic_check_planes(struct
> > > intel_atomic_state *state)
> > > if (ret)
> > > return ret;
> > >
> > > + intel_casf_scaler_compute_config(new_crtc_state);
> > > +
> > > /*
> > > * On some platforms the number of active planes affects
> > > * the planes' minimum cdclk calculation. Add such planes
> diff
> > > --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index f29e5dc3db91..de3867faa4d7 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -1036,6 +1036,19 @@ struct intel_csc_matrix {
> > > u16 postoff[3];
> > > };
> > >
> > > +struct scaler_filter_coeff {
> > > + u16 sign;
> > > + u16 exp;
> > > + u16 mantissa;
> > > +};
> > > +
> > > +struct intel_casf {
> > > +#define SCALER_FILTER_NUM_TAPS 7
> > > + struct scaler_filter_coeff coeff[SCALER_FILTER_NUM_TAPS];
> > > + u8 win_size;
> > > + bool need_scaler;
> > > +};
> > > +
> > > struct intel_crtc_state {
> > > /*
> > > * uapi (drm) state. This is the software state shown to userspace.
> > > @@ -1072,6 +1085,7 @@ struct intel_crtc_state {
> > > struct drm_property_blob *degamma_lut, *gamma_lut,
> *ctm;
> > > struct drm_display_mode mode, pipe_mode,
> adjusted_mode;
> > > enum drm_scaling_filter scaling_filter;
> > > + struct intel_casf casf_params;
> > > } hw;
> > >
> > > /* actual state of LUTs */
> > > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > > b/drivers/gpu/drm/i915/i915_reg.h index 41f4350a7c6c..84b05b57ad52
> > > 100644
> > > --- a/drivers/gpu/drm/i915/i915_reg.h
> > > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > > @@ -2257,6 +2257,8 @@
> > > #define PS_VERT_INT_INVERT_FIELD REG_BIT(20)
> > > #define PS_PROG_SCALE_FACTOR REG_BIT(19) /* tgl+ */
> > > #define PS_PWRUP_PROGRESS REG_BIT(17)
> > > +#define PS_BYPASS_ARMING REG_BIT(10)
> > > +#define PS_DB_STALL REG_BIT(9)
> > > #define PS_V_FILTER_BYPASS REG_BIT(8)
> > > #define PS_VADAPT_EN REG_BIT(7) /* skl/bxt
> > > */
> > > #define PS_VADAPT_MODE_MASK
> REG_GENMASK(6, 5)
> > > /* skl/bxt */
> > > diff --git a/drivers/gpu/drm/xe/Makefile
> > > b/drivers/gpu/drm/xe/Makefile index 8f1c5c329f79..59dc97f30caa
> > > 100644
> > > --- a/drivers/gpu/drm/xe/Makefile
> > > +++ b/drivers/gpu/drm/xe/Makefile
> > > @@ -254,6 +254,7 @@ xe-$(CONFIG_DRM_XE_DISPLAY) += \
> > > i915-display/intel_psr.o \
> > > i915-display/intel_qp_tables.o \
> > > i915-display/intel_quirks.o \
> > > + i915-display/intel_casf.o \
> > > i915-display/intel_snps_phy.o \
> > > i915-display/intel_tc.o \
> > > i915-display/intel_vblank.o \
> > > --
> > > 2.25.1
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