To support ycbcr output, we need a pipe CSC block to do RGB->YCBCR conversion.
Current Intel platforms have only one pipe CSC unit, so we can either do color correction using it, or we can perform RGB->YCBCR conversion.
This function adds a csc handler, which uses recommended bspec values to perform RGB->YCBCR conversion (target color space BT709)
V2: Rebase V3: Rebase V4: Rebase V5: Addressed review comments from Ander - Remove extra line added in the patch - Add the spec details in the commit message - Combine two if(cond) while calling intel_crtc_compute_config V6: Handle YCBCR420 outputs only (Ville)
Cc: Ville Syrjala ville.syrjala@linux.intel.com Cc: Daniel Vetter daniel.vetter@intel.com Cc: Ander Conselvan de Oliveira conselvan2@gmail.com
Signed-off-by: Shashank Sharma shashank.sharma@intel.com --- drivers/gpu/drm/i915/intel_color.c | 47 +++++++++++++++++++++++++++++++++++- drivers/gpu/drm/i915/intel_display.c | 17 +++++++++++++ 2 files changed, 63 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c index 306c6b0..8a5d211 100644 --- a/drivers/gpu/drm/i915/intel_color.c +++ b/drivers/gpu/drm/i915/intel_color.c @@ -41,6 +41,19 @@
#define LEGACY_LUT_LENGTH (sizeof(struct drm_color_lut) * 256)
+/* Post offset values for RGB->YCBCR conversion */ +#define POSTOFF_RGB_TO_YUV_HI 0x800 +#define POSTOFF_RGB_TO_YUV_ME 0x100 +#define POSTOFF_RGB_TO_YUV_LO 0x800 + +/* Direct spec values for RGB->YUV conversion matrix */ +#define CSC_RGB_TO_YUV_RU_GU 0x2ba809d8 +#define CSC_RGB_TO_YUV_BU 0x37e80000 +#define CSC_RGB_TO_YUV_RY_GY 0x1e089cc0 +#define CSC_RGB_TO_YUV_BY 0xb5280000 +#define CSC_RGB_TO_YUV_RV_GV 0xbce89ad8 +#define CSC_RGB_TO_YUV_BV 0x1e080000 + /* * Extract the CSC coefficient from a CTM coefficient (in U32.32 fixed point * format). This macro takes the coefficient we want transformed and the @@ -91,6 +104,35 @@ static void ctm_mult_by_limited(uint64_t *result, int64_t *input) } }
+void i9xx_load_ycbcr_conversion_matrix(struct intel_crtc *intel_crtc) +{ + int pipe = intel_crtc->pipe; + struct drm_i915_private *dev_priv = to_i915(intel_crtc->base.dev); + + /* We don't use high values for conversion */ + I915_WRITE(PIPE_CSC_PREOFF_HI(pipe), 0); + I915_WRITE(PIPE_CSC_PREOFF_ME(pipe), 0); + I915_WRITE(PIPE_CSC_PREOFF_LO(pipe), 0); + + /* Program direct spec values for RGB to YCBCR conversion matrix */ + I915_WRITE(PIPE_CSC_COEFF_RU_GU(pipe), CSC_RGB_TO_YUV_RU_GU); + I915_WRITE(PIPE_CSC_COEFF_BU(pipe), CSC_RGB_TO_YUV_BU); + + I915_WRITE(PIPE_CSC_COEFF_RY_GY(pipe), CSC_RGB_TO_YUV_RY_GY); + I915_WRITE(PIPE_CSC_COEFF_BY(pipe), CSC_RGB_TO_YUV_BY); + + I915_WRITE(PIPE_CSC_COEFF_RV_GV(pipe), CSC_RGB_TO_YUV_RV_GV); + I915_WRITE(PIPE_CSC_COEFF_BV(pipe), CSC_RGB_TO_YUV_BV); + + /* Spec postoffset values */ + I915_WRITE(PIPE_CSC_POSTOFF_HI(pipe), POSTOFF_RGB_TO_YUV_HI); + I915_WRITE(PIPE_CSC_POSTOFF_ME(pipe), POSTOFF_RGB_TO_YUV_ME); + I915_WRITE(PIPE_CSC_POSTOFF_LO(pipe), POSTOFF_RGB_TO_YUV_LO); + + /* CSC mode before gamma */ + I915_WRITE(PIPE_CSC_MODE(pipe), 0); +} + /* Set up the pipe CSC unit. */ static void i9xx_load_csc_matrix(struct drm_crtc_state *crtc_state) { @@ -101,7 +143,10 @@ static void i9xx_load_csc_matrix(struct drm_crtc_state *crtc_state) uint16_t coeffs[9] = { 0, }; struct intel_crtc_state *intel_crtc_state = to_intel_crtc_state(crtc_state);
- if (crtc_state->ctm) { + if (intel_crtc_state->ycbcr420) { + i9xx_load_ycbcr_conversion_matrix(intel_crtc); + return; + } else if (crtc_state->ctm) { struct drm_color_ctm *ctm = (struct drm_color_ctm *)crtc_state->ctm->data; uint64_t input[9] = { 0, }; diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index b4a6415..c5ff568 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6288,6 +6288,23 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc, return -EINVAL; }
+ /* YCBCR420 feasibility check */ + if (pipe_config->ycbcr420) { + struct drm_crtc_state *drm_state = &pipe_config->base; + + /* + * There is only one pipe CSC unit per pipe, and we need that + * for output conversion from RGB->YCBCR. So if CTM is already + * applied we can't support YCBCR420 output. + */ + if (drm_state->ctm) { + DRM_ERROR("YCBCR420 and CTM is not possible\n"); + return -EINVAL; + } + + DRM_DEBUG_KMS("YCBCR420 output is possible from CRTC\n"); + } + /* * Pipe horizontal size must be even in: * - DVO ganged mode