From 02ae8ba9664081a74cafe6662e64b3d7b8b292e6 Mon Sep 17 00:00:00 2001 From: Shashank Sharma Date: Wed, 12 Jun 2019 12:15:00 +0530 Subject: [PATCH] drm/i915/icl: Add Multi-segmented gamma support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit ICL introduces a new gamma correction mode in display engine, called multi-segmented-gamma mode. This mode allows users to program the darker region of the gamma curve with sueprfine precision. An example use case for this is HDR curves (like PQ ST-2084). If we plot a gamma correction curve from value range between 0.0 to 1.0, ICL's multi-segment has 3 different sections: - superfine segment: 9 values, ranges between 0 - 1/(128 * 256) - fine segment: 257 values, ranges between 0 - 1/(128) - corase segment: 257 values, ranges between 0 - 1 This patch: - Changes gamma LUTs size for ICL/GEN11 to 262144 entries (8 * 128 * 256), so that userspace can program with highest precision supported. - Changes default gamma mode (non-legacy) to multi-segmented-gamma mode. - Adds functions to program/detect multi-segment gamma. V2: Addressed review comments from Ville - separate function for superfine and fine segments. - remove enum for segments. - reuse last entry of the LUT as gc_max value. - replace if() ....cond with switch...case in icl_load_luts. - add an entry variable, instead of 'word' V3: Addressed review comments from Ville - extra newline - s/entry/color/ - remove LUT size checks - program ilk_lut_12p4_ldw value before ilk_lut_12p4_udw - Change the comments in description of fine and coarse segments, and try to make more sense. - use 8 * 128 instead of 1024 - add 1 entry in LUT for GCMAX V4: Addressed review comments from Ville - Remove unused macro - missing shift entry in blue - pick correct entry for GCMAX - Added Ville's R-B Note: Tested and confirmed the programming sequence of odd/even registers in the HW. The correct sequence should be: ilk_lut_12p4_udw ilk_lut_12p4_ldw v5: Addressed Ville's review comments and renamed odd/even register helpers to be more consistent with the values. Cc: Ville Syrjälä Cc: Maarten Lankhorst Cc: Daniel Vetter Reviewed-by: Ville Syrjälä Suggested-by: Ville Syrjälä Signed-off-by: Shashank Sharma Signed-off-by: Uma Shankar Signed-off-by: Maarten Lankhorst Link: https://patchwork.freedesktop.org/patch/msgid/1560321900-18318-5-git-send-email-uma.shankar@intel.com --- drivers/gpu/drm/i915/i915_pci.c | 2 +- drivers/gpu/drm/i915/intel_color.c | 126 ++++++++++++++++++++++++++++- 2 files changed, 123 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c index 482f1d0f1770..ed6b1f6402c4 100644 --- a/drivers/gpu/drm/i915/i915_pci.c +++ b/drivers/gpu/drm/i915/i915_pci.c @@ -747,7 +747,7 @@ static const struct intel_device_info intel_cannonlake_info = { GEN(11), \ .ddb_size = 2048, \ .has_logical_ring_elsq = 1, \ - .color = { .degamma_lut_size = 33, .gamma_lut_size = 1024 } + .color = { .degamma_lut_size = 33, .gamma_lut_size = 262145 } static const struct intel_device_info intel_icelake_11_info = { GEN11_FEATURES, diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c index 46443ae06bf5..23a84dd7989f 100644 --- a/drivers/gpu/drm/i915/intel_color.c +++ b/drivers/gpu/drm/i915/intel_color.c @@ -41,6 +41,7 @@ #define CTM_COEFF_ABS(coeff) ((coeff) & (CTM_COEFF_SIGN - 1)) #define LEGACY_LUT_LENGTH 256 + /* * Extract the CSC coefficient from a CTM coefficient (in U32.32 fixed point * format). This macro takes the coefficient we want transformed and the @@ -767,6 +768,116 @@ static void glk_load_luts(const struct intel_crtc_state *crtc_state) } } +/* ilk+ "12.4" interpolated format (high 10 bits) */ +static u32 ilk_lut_12p4_udw(const struct drm_color_lut *color) +{ + return (color->red >> 6) << 20 | (color->green >> 6) << 10 | + (color->blue >> 6); +} + +/* ilk+ "12.4" interpolated format (low 6 bits) */ +static u32 ilk_lut_12p4_ldw(const struct drm_color_lut *color) +{ + return (color->red & 0x3f) << 24 | (color->green & 0x3f) << 14 | + (color->blue & 0x3f) << 4; +} + +static void +icl_load_gcmax(const struct intel_crtc_state *crtc_state, + const struct drm_color_lut *color) +{ + struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc); + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); + enum pipe pipe = crtc->pipe; + + /* Fixme: LUT entries are 16 bit only, so we can prog 0xFFFF max */ + I915_WRITE(PREC_PAL_GC_MAX(pipe, 0), color->red); + I915_WRITE(PREC_PAL_GC_MAX(pipe, 1), color->green); + I915_WRITE(PREC_PAL_GC_MAX(pipe, 2), color->blue); +} + +static void +icl_program_gamma_superfine_segment(const struct intel_crtc_state *crtc_state) +{ + struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc); + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); + const struct drm_property_blob *blob = crtc_state->base.gamma_lut; + const struct drm_color_lut *lut = blob->data; + enum pipe pipe = crtc->pipe; + u32 i; + + /* + * Every entry in the multi-segment LUT is corresponding to a superfine + * segment step which is 1/(8 * 128 * 256). + * + * Superfine segment has 9 entries, corresponding to values + * 0, 1/(8 * 128 * 256), 2/(8 * 128 * 256) .... 8/(8 * 128 * 256). + */ + I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT); + + for (i = 0; i < 9; i++) { + const struct drm_color_lut *entry = &lut[i]; + + I915_WRITE(PREC_PAL_MULTI_SEG_DATA(pipe), + ilk_lut_12p4_ldw(entry)); + I915_WRITE(PREC_PAL_MULTI_SEG_DATA(pipe), + ilk_lut_12p4_udw(entry)); + } +} + +static void +icl_program_gamma_multi_segment(const struct intel_crtc_state *crtc_state) +{ + struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc); + struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); + const struct drm_property_blob *blob = crtc_state->base.gamma_lut; + const struct drm_color_lut *lut = blob->data; + const struct drm_color_lut *entry; + enum pipe pipe = crtc->pipe; + u32 i; + + /* + * + * Program Fine segment (let's call it seg2)... + * + * Fine segment's step is 1/(128 * 256) ie 1/(128 * 256), 2/(128*256) + * ... 256/(128*256). So in order to program fine segment of LUT we + * need to pick every 8'th entry in LUT, and program 256 indexes. + * + * PAL_PREC_INDEX[0] and PAL_PREC_INDEX[1] map to seg2[1], + * with seg2[0] being unused by the hardware. + */ + I915_WRITE(PREC_PAL_INDEX(pipe), PAL_PREC_AUTO_INCREMENT); + for (i = 1; i < 257; i++) { + entry = &lut[i * 8]; + I915_WRITE(PREC_PAL_DATA(pipe), ilk_lut_12p4_ldw(entry)); + I915_WRITE(PREC_PAL_DATA(pipe), ilk_lut_12p4_udw(entry)); + } + + /* + * Program Coarse segment (let's call it seg3)... + * + * Coarse segment's starts from index 0 and it's step is 1/256 ie 0, + * 1/256, 2/256 ...256/256. As per the description of each entry in LUT + * above, we need to pick every (8 * 128)th entry in LUT, and + * program 256 of those. + * + * Spec is not very clear about if entries seg3[0] and seg3[1] are + * being used or not, but we still need to program these to advance + * the index. + */ + for (i = 0; i < 256; i++) { + entry = &lut[i * 8 * 128]; + I915_WRITE(PREC_PAL_DATA(pipe), ilk_lut_12p4_ldw(entry)); + I915_WRITE(PREC_PAL_DATA(pipe), ilk_lut_12p4_udw(entry)); + } + + /* The last entry in the LUT is to be programmed in GCMAX */ + entry = &lut[256 * 8 * 128]; + icl_load_gcmax(crtc_state, entry); + ivb_load_lut_ext_max(crtc); +} + static void icl_load_luts(const struct intel_crtc_state *crtc_state) { const struct drm_property_blob *gamma_lut = crtc_state->base.gamma_lut; @@ -775,10 +886,17 @@ static void icl_load_luts(const struct intel_crtc_state *crtc_state) if (crtc_state->base.degamma_lut) glk_load_degamma_lut(crtc_state); - if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) == - GAMMA_MODE_MODE_8BIT) { + switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) { + case GAMMA_MODE_MODE_8BIT: i9xx_load_luts(crtc_state); - } else { + break; + + case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED: + icl_program_gamma_superfine_segment(crtc_state); + icl_program_gamma_multi_segment(crtc_state); + break; + + default: bdw_load_lut_10(crtc, gamma_lut, PAL_PREC_INDEX_VALUE(0)); ivb_load_lut_ext_max(crtc); } @@ -1219,7 +1337,7 @@ static u32 icl_gamma_mode(const struct intel_crtc_state *crtc_state) crtc_state_is_legacy_gamma(crtc_state)) gamma_mode |= GAMMA_MODE_MODE_8BIT; else - gamma_mode |= GAMMA_MODE_MODE_10BIT; + gamma_mode |= GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED; return gamma_mode; } -- 2.45.2