From: Nemesa Garg Date: Tue, 28 Oct 2025 12:07:41 +0000 (+0530) Subject: drm/i915/display: Compute the scaler coefficients X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=76f51cdc5d45a5497f7f2578ff81fd3efcabb3bd;p=thirdparty%2Fkernel%2Flinux.git drm/i915/display: Compute the scaler 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. Add helper to compute and set the scaler coefficients. 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] v5: Fix build issue v6: Add new function for writing coefficients[Ankit] v7: Add cooments and add a scaler id check [Ankit] v8: Remove casf_enable from here[Ankit] v9: Removed REG and use shift operator[Jani] v10: Remove filter macros v11: Add casf_write_coeff function to casf_enable Signed-off-by: Nemesa Garg Reviewed-by: Ankit Nautiyal Link: https://patch.msgid.link/20251028120747.3027332-6-ankit.k.nautiyal@intel.com Signed-off-by: Jani Nikula --- diff --git a/drivers/gpu/drm/i915/display/intel_casf.c b/drivers/gpu/drm/i915/display/intel_casf.c index bd63fdafb898f..ee24e5957d3d3 100644 --- a/drivers/gpu/drm/i915/display/intel_casf.c +++ b/drivers/gpu/drm/i915/display/intel_casf.c @@ -130,6 +130,8 @@ int intel_casf_compute_config(struct intel_crtc_state *crtc_state) intel_casf_compute_win_size(crtc_state); + intel_casf_scaler_compute_config(crtc_state); + return 0; } @@ -153,6 +155,101 @@ void intel_casf_sharpness_get_config(struct intel_crtc_state *crtc_state) } } +static int casf_coeff_tap(int i) +{ + return i % SCALER_FILTER_NUM_TAPS; +} + +static u32 casf_coeff(struct intel_crtc_state *crtc_state, int t) +{ + struct scaler_filter_coeff value; + u32 coeff; + + value = crtc_state->hw.casf_params.coeff[t]; + value.sign = 0; + + coeff = value.sign << 15 | value.exp << 12 | value.mantissa << 3; + return coeff; +} + +/* + * 17 phase of 7 taps requires 119 coefficients in 60 dwords per set. + * To enable casf: program scaler coefficients with the coeffients + * that are calculated and stored in hw.casf_params.coeff as per + * SCALER_COEFFICIENT_FORMAT + */ +static void intel_casf_write_coeff(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; + + if (id != 1) { + drm_WARN(display->drm, 0, "Second scaler not enabled\n"); + return; + } + + intel_de_write_fw(display, GLK_PS_COEF_INDEX_SET(crtc->pipe, id, 0), + PS_COEF_INDEX_AUTO_INC); + + for (i = 0; i < 17 * SCALER_FILTER_NUM_TAPS; i += 2) { + u32 tmp; + int t; + + t = casf_coeff_tap(i); + tmp = casf_coeff(crtc_state, t); + + t = casf_coeff_tap(i + 1); + tmp |= casf_coeff(crtc_state, t) << 16; + + intel_de_write_fw(display, GLK_PS_COEF_DATA_SET(crtc->pipe, id, 0), + 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; + } +} + +void intel_casf_scaler_compute_config(struct intel_crtc_state *crtc_state) +{ + const u16 *filtercoeff; + u16 filter_coeff[SCALER_FILTER_NUM_TAPS]; + u16 sumcoeff = 0; + int 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); + + for (i = 0; i < SCALER_FILTER_NUM_TAPS; i++) { + filter_coeff[i] = (*(filtercoeff + i) * 100 / sumcoeff); + convert_sharpness_coef_binary(&crtc_state->hw.casf_params.coeff[i], + filter_coeff[i]); + } +} + void intel_casf_enable(struct intel_crtc_state *crtc_state) { struct intel_display *display = to_intel_display(crtc_state); @@ -161,6 +258,8 @@ void intel_casf_enable(struct intel_crtc_state *crtc_state) intel_casf_filter_lut_load(crtc, crtc_state); + intel_casf_write_coeff(crtc_state); + sharpness_ctl = FILTER_EN | FILTER_STRENGTH(crtc_state->hw.casf_params.strength); sharpness_ctl |= crtc_state->hw.casf_params.win_size; diff --git a/drivers/gpu/drm/i915/display/intel_casf.h b/drivers/gpu/drm/i915/display/intel_casf.h index 7538718802795..203a5587921c5 100644 --- a/drivers/gpu/drm/i915/display/intel_casf.h +++ b/drivers/gpu/drm/i915/display/intel_casf.h @@ -15,5 +15,6 @@ void intel_casf_update_strength(struct intel_crtc_state *new_crtc_state); void intel_casf_sharpness_get_config(struct intel_crtc_state *crtc_state); void intel_casf_enable(struct intel_crtc_state *crtc_state); void intel_casf_disable(const 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_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 2afb346249ef2..00600134bda0a 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -961,7 +961,15 @@ enum intel_panel_replay_dsc_support { INTEL_DP_PANEL_REPLAY_DSC_SELECTIVE_UPDATE, }; +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 strength; u8 win_size; bool casf_enable;