[v6 16/16] drm/i915: Enable Plane CSC

[Uma Shankar]

Implement plane CSC on ICL.

Signed-off-by: Uma Shankar <uma.shankar at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h      |  1 +
 drivers/gpu/drm/i915/intel_color.c   | 86 ++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/intel_display.c |  3 ++
 3 files changed, 90 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 38e0c46..4b1ab54 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6750,6 +6750,7 @@ enum {
 #define _PLANE_COLOR_CTL_3_A			0x703CC /* GLK+ */
 #define   PLANE_COLOR_PIPE_GAMMA_ENABLE		(1 << 30) /* Pre-ICL */
 #define   PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE	(1 << 28)
+#define   PLANE_COLOR_PLANE_CSC_ENABLE		(1 << 21) /* ICL+ */
 #define   PLANE_COLOR_INPUT_CSC_ENABLE		(1 << 20) /* ICL+ */
 #define   PLANE_COLOR_PIPE_CSC_ENABLE		(1 << 23) /* Pre-ICL */
 #define   PLANE_COLOR_CSC_MODE_BYPASS			(0 << 17)
diff --git a/drivers/gpu/drm/i915/intel_color.c b/drivers/gpu/drm/i915/intel_color.c
index aa73f88..ed21d98 100644
--- a/drivers/gpu/drm/i915/intel_color.c
+++ b/drivers/gpu/drm/i915/intel_color.c
@@ -606,6 +606,90 @@ static void bdw_load_plane_gamma_lut(const struct drm_plane_state *state,
 	}
 }
 
+static void icl_load_plane_csc_matrix(const struct drm_plane_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->plane->dev);
+	enum pipe pipe = to_intel_plane(state->plane)->pipe;
+	enum plane_id plane = to_intel_plane(state->plane)->id;
+	u16 coeffs[9] = {};
+	u16 postoff = 0;
+	int i;
+
+	if (state->ctm) {
+		struct drm_color_ctm *ctm = state->ctm->data;
+		const u64 *input;
+
+		input = ctm->matrix;
+
+		/*
+		 * Convert fixed point S31.32 input to format supported by the
+		 * hardware.
+		 */
+		for (i = 0; i < ARRAY_SIZE(coeffs); i++) {
+			u64 abs_coeff = ((1ULL << 63) - 1) & input[i];
+
+			/*
+			 * Clamp input value to min/max supported by
+			 * hardware.
+			 */
+			abs_coeff = clamp_val(abs_coeff, 0, CTM_COEFF_4_0 - 1);
+
+			/* sign bit */
+			if (CTM_COEFF_NEGATIVE(input[i]))
+				coeffs[i] |= 1 << 15;
+
+			if (abs_coeff < CTM_COEFF_0_125)
+				coeffs[i] |= (3 << 12) |
+					ILK_CSC_COEFF_FP(abs_coeff, 12);
+			else if (abs_coeff < CTM_COEFF_0_25)
+				coeffs[i] |= (2 << 12) |
+					ILK_CSC_COEFF_FP(abs_coeff, 11);
+			else if (abs_coeff < CTM_COEFF_0_5)
+				coeffs[i] |= (1 << 12) |
+					ILK_CSC_COEFF_FP(abs_coeff, 10);
+			else if (abs_coeff < CTM_COEFF_1_0)
+				coeffs[i] |= ILK_CSC_COEFF_FP(abs_coeff, 9);
+			else if (abs_coeff < CTM_COEFF_2_0)
+				coeffs[i] |= (7 << 12) |
+					ILK_CSC_COEFF_FP(abs_coeff, 8);
+			else
+				coeffs[i] |= (6 << 12) |
+					ILK_CSC_COEFF_FP(abs_coeff, 7);
+		}
+	} else {
+		/*
+		 * Load an identity matrix if no coefficients are provided.
+		 *
+		 * TODO: Check what kind of values actually come out of the
+		 * pipe with these coeff/postoff values and adjust to get the
+		 * best accuracy. Perhaps we even need to take the bpc value
+		 * into consideration.
+		 */
+		for (i = 0; i < 3; i++)
+			coeffs[i * 3 + i] = ILK_CSC_COEFF_1_0;
+	}
+
+	I915_WRITE(PLANE_CSC_COEFF(pipe, plane, 0),
+		   coeffs[0] << 16 | coeffs[1]);
+	I915_WRITE(PLANE_CSC_COEFF(pipe, plane, 1), coeffs[2] << 16);
+
+	I915_WRITE(PLANE_CSC_COEFF(pipe, plane, 3),
+		   coeffs[3] << 16 | coeffs[4]);
+	I915_WRITE(PLANE_CSC_COEFF(pipe, plane, 4), coeffs[5] << 16);
+
+	I915_WRITE(PLANE_CSC_COEFF(pipe, plane, 5),
+		   coeffs[6] << 16 | coeffs[7]);
+	I915_WRITE(PLANE_CSC_COEFF(pipe, plane, 6), coeffs[8] << 16);
+
+	I915_WRITE(PLANE_CSC_PREOFF(pipe, plane, 0), 0);
+	I915_WRITE(PLANE_CSC_PREOFF(pipe, plane, 1), 0);
+	I915_WRITE(PLANE_CSC_PREOFF(pipe, plane, 2), 0);
+
+	I915_WRITE(PLANE_CSC_POSTOFF(pipe, plane, 0), postoff);
+	I915_WRITE(PLANE_CSC_POSTOFF(pipe, plane, 1), postoff);
+	I915_WRITE(PLANE_CSC_POSTOFF(pipe, plane, 2), postoff);
+}
+
 /* Loads the palette/gamma unit for the CRTC on Broadwell+. */
 static void broadwell_load_plane_luts(const struct drm_plane_state *state)
 {
@@ -777,6 +861,8 @@ static void icl_load_plane_luts(const struct drm_plane_state *state)
 
 	plane_state->gamma_mode |= PLANE_COLOR_PLANE_PRECSC_GAMMA_ENABLE;
 	plane_state->gamma_mode |= ~PLANE_COLOR_PLANE_GAMMA_DISABLE;
+
+	icl_load_plane_csc_matrix(state);
 }
 
 static void glk_load_degamma_lut(const struct intel_crtc_state *crtc_state)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 78d161e..1602d8a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -3824,6 +3824,9 @@ u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
 		plane_color_ctl |= PLANE_COLOR_INPUT_CSC_ENABLE;
 	}
 
+	if (plane_state->base.ctm)
+		plane_color_ctl |= PLANE_COLOR_PLANE_CSC_ENABLE;
+
 	return plane_color_ctl;
 }
 
-- 
1.9.1