drm/i915/icl: Enable Plane Input CSC for YUV to RGB Conversion

Plane input CSC needs to be enabled to convert frambuffers from
YUV to RGB. This is needed for bottom 3 planes on ICL, rest of
the planes have hardcoded conversion and taken care by the legacy
code.

This patch defines the co-efficient values for YUV to RGB conversion
in BT709 and BT601 formats. It programs the coefficients and enables
the plane input csc unit in hardware.

This has been verified and tested by Maarten and the change is working
as expecpted.

v2: Addressed Maarten's and Ville's review comments and added the
coefficients in a 2D array instead of independent Macros.

v3: Added individual coefficient matrix (9 values) instead of 6
register values as per Maarten's comment. Also addresed a shift
issue with B channel coefficient.

v4: Added support for Limited Range Color Handling

v5: Fixed Matt and Maarten's review comments.

v6: Added human readable matrix values for YUV to RGB Conversion along
with just the bspec register values, as per Matt's suggestion.

v7: Refactored the code, move csc coefficient programming function to
intel_sprite.c and made it static as per Ville's review comment.

v8: Addressed Ville's review comment. Called the coefficient programming
from within the skl_program_plane and used I915_WRITE_FW instead of
I915_WRITE.

v9: Fixed Ville's review comments.
Signed-off-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1541099420-12419-3-git-send-email-uma.shankar@intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -3655,6 +3655,7 @@ u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
 	struct drm_i915_private *dev_priv =
 		to_i915(plane_state->base.plane->dev);
 	const struct drm_framebuffer *fb = plane_state->base.fb;
+	struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
 	u32 plane_color_ctl = 0;
 
 	if (INTEL_GEN(dev_priv) < 11) {
@@ -3664,7 +3665,7 @@ u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
 	plane_color_ctl |= PLANE_COLOR_PLANE_GAMMA_DISABLE;
 	plane_color_ctl |= glk_plane_color_ctl_alpha(plane_state);
 
-	if (fb->format->is_yuv) {
+	if (fb->format->is_yuv && !icl_is_hdr_plane(plane)) {
 		if (plane_state->base.color_encoding == DRM_COLOR_YCBCR_BT709)
 			plane_color_ctl |= PLANE_COLOR_CSC_MODE_YUV709_TO_RGB709;
 		else
@@ -3672,6 +3673,8 @@ u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
 
 		if (plane_state->base.color_range == DRM_COLOR_YCBCR_FULL_RANGE)
 			plane_color_ctl |= PLANE_COLOR_YUV_RANGE_CORRECTION_DISABLE;
+	} else if (fb->format->is_yuv) {
+		plane_color_ctl |= PLANE_COLOR_INPUT_CSC_ENABLE;
 	}
 
 	return plane_color_ctl;

drivers/gpu/drm/i915/intel_sprite.c

@@ -40,6 +40,7 @@
 #include "intel_frontbuffer.h"
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
+#include <drm/drm_color_mgmt.h>
 
 int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
 			     int usecs)
@@ -361,6 +362,108 @@ skl_program_scaler(struct drm_i915_private *dev_priv,
 		      ((crtc_w + 1) << 16)|(crtc_h + 1));
 }
 
+/* Preoffset values for YUV to RGB Conversion */
+#define PREOFF_YUV_TO_RGB_HI		0x1800
+#define PREOFF_YUV_TO_RGB_ME		0x1F00
+#define PREOFF_YUV_TO_RGB_LO		0x1800
+
+#define  ROFF(x)          (((x) & 0xffff) << 16)
+#define  GOFF(x)          (((x) & 0xffff) << 0)
+#define  BOFF(x)          (((x) & 0xffff) << 16)
+
+static void
+icl_program_input_csc_coeff(const struct intel_crtc_state *crtc_state,
+			    const struct intel_plane_state *plane_state)
+{
+	struct drm_i915_private *dev_priv =
+		to_i915(plane_state->base.plane->dev);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+	enum pipe pipe = crtc->pipe;
+	struct intel_plane *plane = to_intel_plane(plane_state->base.plane);
+	enum plane_id plane_id = plane->id;
+
+	static const u16 input_csc_matrix[][9] = {
+		/*
+		 * BT.601 full range YCbCr -> full range RGB
+		 * The matrix required is :
+		 * [1.000, 0.000, 1.371,
+		 *  1.000, -0.336, -0.698,
+		 *  1.000, 1.732, 0.0000]
+		 */
+		[DRM_COLOR_YCBCR_BT601] = {
+			0x7AF8, 0x7800, 0x0,
+			0x8B28, 0x7800, 0x9AC0,
+			0x0, 0x7800, 0x7DD8,
+		},
+		/*
+		 * BT.709 full range YCbCr -> full range RGB
+		 * The matrix required is :
+		 * [1.000, 0.000, 1.574,
+		 *  1.000, -0.187, -0.468,
+		 *  1.000, 1.855, 0.0000]
+		 */
+		[DRM_COLOR_YCBCR_BT709] = {
+			0x7C98, 0x7800, 0x0,
+			0x9EF8, 0x7800, 0xABF8,
+			0x0, 0x7800,  0x7ED8,
+		},
+	};
+
+	/* Matrix for Limited Range to Full Range Conversion */
+	static const u16 input_csc_matrix_lr[][9] = {
+		/*
+		 * BT.601 Limted range YCbCr -> full range RGB
+		 * The matrix required is :
+		 * [1.164384, 0.000, 1.596370,
+		 *  1.138393, -0.382500, -0.794598,
+		 *  1.138393, 1.971696, 0.0000]
+		 */
+		[DRM_COLOR_YCBCR_BT601] = {
+			0x7CC8, 0x7950, 0x0,
+			0x8CB8, 0x7918, 0x9C40,
+			0x0, 0x7918, 0x7FC8,
+		},
+		/*
+		 * BT.709 Limited range YCbCr -> full range RGB
+		 * The matrix required is :
+		 * [1.164, 0.000, 1.833671,
+		 *  1.138393, -0.213249, -0.532909,
+		 *  1.138393, 2.112402, 0.0000]
+		 */
+		[DRM_COLOR_YCBCR_BT709] = {
+			0x7EA8, 0x7950, 0x0,
+			0x8888, 0x7918, 0xADA8,
+			0x0, 0x7918,  0x6870,
+		},
+	};
+	const u16 *csc;
+
+	if (plane_state->base.color_range == DRM_COLOR_YCBCR_FULL_RANGE)
+		csc = input_csc_matrix[plane_state->base.color_encoding];
+	else
+		csc = input_csc_matrix_lr[plane_state->base.color_encoding];
+
+	I915_WRITE_FW(PLANE_INPUT_CSC_COEFF(pipe, plane_id, 0), ROFF(csc[0]) |
+		      GOFF(csc[1]));
+	I915_WRITE_FW(PLANE_INPUT_CSC_COEFF(pipe, plane_id, 1), BOFF(csc[2]));
+	I915_WRITE_FW(PLANE_INPUT_CSC_COEFF(pipe, plane_id, 2), ROFF(csc[3]) |
+		      GOFF(csc[4]));
+	I915_WRITE_FW(PLANE_INPUT_CSC_COEFF(pipe, plane_id, 3), BOFF(csc[5]));
+	I915_WRITE_FW(PLANE_INPUT_CSC_COEFF(pipe, plane_id, 4), ROFF(csc[6]) |
+		      GOFF(csc[7]));
+	I915_WRITE_FW(PLANE_INPUT_CSC_COEFF(pipe, plane_id, 5), BOFF(csc[8]));
+
+	I915_WRITE_FW(PLANE_INPUT_CSC_PREOFF(pipe, plane_id, 0),
+		      PREOFF_YUV_TO_RGB_HI);
+	I915_WRITE_FW(PLANE_INPUT_CSC_PREOFF(pipe, plane_id, 1),
+		      PREOFF_YUV_TO_RGB_ME);
+	I915_WRITE_FW(PLANE_INPUT_CSC_PREOFF(pipe, plane_id, 2),
+		      PREOFF_YUV_TO_RGB_LO);
+	I915_WRITE_FW(PLANE_INPUT_CSC_POSTOFF(pipe, plane_id, 0), 0x0);
+	I915_WRITE_FW(PLANE_INPUT_CSC_POSTOFF(pipe, plane_id, 1), 0x0);
+	I915_WRITE_FW(PLANE_INPUT_CSC_POSTOFF(pipe, plane_id, 2), 0x0);
+}
+
 static void
 skl_program_plane(struct intel_plane *plane,
 		  const struct intel_crtc_state *crtc_state,
@@ -381,6 +484,7 @@ skl_program_plane(struct intel_plane *plane,
 	uint32_t src_w = drm_rect_width(&plane_state->base.src) >> 16;
 	uint32_t src_h = drm_rect_height(&plane_state->base.src) >> 16;
 	struct intel_plane *linked = plane_state->linked_plane;
+	const struct drm_framebuffer *fb = plane_state->base.fb;
 	unsigned long irqflags;
 	u32 keymsk = 0, keymax = 0;
 
@@ -394,6 +498,9 @@ skl_program_plane(struct intel_plane *plane,
 		I915_WRITE_FW(PLANE_COLOR_CTL(pipe, plane_id),
 			      plane_state->color_ctl);
 
+	if (fb->format->is_yuv && icl_is_hdr_plane(plane))
+		icl_program_input_csc_coeff(crtc_state, plane_state);
+
 	if (key->flags) {
 		I915_WRITE_FW(PLANE_KEYVAL(pipe, plane_id), key->min_value);