BDW/SKL/BXT supports Degamma color correction feature, which linearizes the non-linearity due to gamma encoded color values. This will be applied before Color Transformation.
This patch does the following: 1. Adds the core function to program DeGamma correction values for BDW/SKL/BXT platform 2. Adds DeGamma correction macros/defines
Signed-off-by: Shashank Sharma shashank.sharma@intel.com Signed-off-by: Kausal Malladi kausalmalladi@gmail.com --- drivers/gpu/drm/i915/intel_color_manager.c | 58 ++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_color_manager.c b/drivers/gpu/drm/i915/intel_color_manager.c index cf85bc3..42fd2f5 100644 --- a/drivers/gpu/drm/i915/intel_color_manager.c +++ b/drivers/gpu/drm/i915/intel_color_manager.c @@ -310,6 +310,62 @@ static int bdw_set_gamma(struct drm_device *dev, struct drm_property_blob *blob, return 0; }
+static int bdw_set_degamma(struct drm_device *dev, + struct drm_property_blob *blob, struct drm_crtc *crtc) +{ + enum pipe pipe; + int num_samples; + u32 index, mode; + u32 pal_prec_index, pal_prec_data; + struct drm_palette *degamma_data; + struct drm_crtc_state *state = crtc->state; + struct drm_i915_private *dev_priv = dev->dev_private; + struct drm_r32g32b32 *correction_values = NULL; + + if (WARN_ON(!blob)) + return -EINVAL; + + degamma_data = (struct drm_palette *)blob->data; + pipe = to_intel_crtc(crtc)->pipe; + num_samples = degamma_data->num_samples; + + if (num_samples == GAMMA_DISABLE_VALS) { + /* Disable degamma on Pipe */ + mode = I915_READ(GAMMA_MODE(pipe)) & ~GAMMA_MODE_MODE_MASK; + I915_WRITE(GAMMA_MODE(pipe), mode | GAMMA_MODE_MODE_8BIT); + + state->palette_before_ctm_blob = NULL; + DRM_DEBUG_DRIVER("Disabling degamma on Pipe %c\n", + pipe_name(pipe)); + return 0; + } + + if (num_samples != BDW_SPLITGAMMA_MAX_VALS) { + DRM_ERROR("Invalid number of samples\n"); + return -EINVAL; + } + + pal_prec_index = _PREC_PAL_INDEX(pipe); + pal_prec_data = _PREC_PAL_DATA(pipe); + correction_values = degamma_data->lut; + + index = I915_READ(pal_prec_index); + index |= BDW_INDEX_AUTO_INCREMENT | BDW_INDEX_SPLIT_MODE; + I915_WRITE(pal_prec_index, index); + + bdw_write_10bit_gamma_precision(dev, correction_values, + pal_prec_data, BDW_SPLITGAMMA_MAX_VALS); + + /* Enable degamma on Pipe */ + mode = I915_READ(GAMMA_MODE(pipe)); + mode &= ~GAMMA_MODE_MODE_MASK; + I915_WRITE(GAMMA_MODE(pipe), mode | GAMMA_MODE_MODE_SPLIT); + DRM_DEBUG_DRIVER("degamma correction enabled on Pipe %c\n", + pipe_name(pipe)); + + return 0; +} + static s32 chv_prepare_csc_coeff(s64 csc_value) { s32 csc_int_value; @@ -601,6 +657,8 @@ void intel_color_manager_crtc_commit(struct drm_device *dev, /* Degamma correction */ if (IS_CHERRYVIEW(dev)) ret = chv_set_degamma(dev, blob, crtc); + else if (IS_BROADWELL(dev) || IS_GEN9(dev)) + ret = bdw_set_degamma(dev, blob, crtc);
if (ret) DRM_ERROR("set degamma correction failed\n");