drm/i915: Fix plane YCbCr->RGB conversion for GLK

On GLK the plane CSC controls moved into the COLOR_CTL register.
Update the code to progam the YCbCr->RGB CSC mode correctly when
faced with an YCbCr framebuffer.

The spec is rather confusing as it calls the mode "YUV601 to RGB709".
I'm going to assume that just means it's going to use the YCbCr->RGB
matrix as specified in BT.601 and doesn't actually change the gamut.

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: Russell King - ARM Linux <linux@armlinux.org.uk>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
Cc: Uma Shankar <uma.shankar@intel.com>
Cc: Shashank Sharma <shashank.sharma@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180214192327.3250-6-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>

drivers/gpu/drm/i915/i915_reg.h

@@ -6436,6 +6436,11 @@ enum {
 #define _PLANE_COLOR_CTL_3_A			0x703CC /* GLK+ */
 #define   PLANE_COLOR_PIPE_GAMMA_ENABLE		(1 << 30)
 #define   PLANE_COLOR_PIPE_CSC_ENABLE		(1 << 23)
+#define   PLANE_COLOR_CSC_MODE_BYPASS			(0 << 17)
+#define   PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709		(1 << 17)
+#define   PLANE_COLOR_CSC_MODE_YUV709_TO_RGB709		(2 << 17)
+#define   PLANE_COLOR_CSC_MODE_YUV2020_TO_RGB2020	(3 << 17)
+#define   PLANE_COLOR_CSC_MODE_RGB709_TO_RGB2020	(4 << 17)
 #define   PLANE_COLOR_PLANE_GAMMA_DISABLE	(1 << 13)
 #define   PLANE_COLOR_ALPHA_MASK		(0x3 << 4)
 #define   PLANE_COLOR_ALPHA_DISABLE		(0 << 4)

drivers/gpu/drm/i915/intel_display.c

@@ -3565,6 +3565,9 @@ 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(fb->format->format);
 
+	if (intel_format_is_yuv(fb->format->format))
+		plane_color_ctl |= PLANE_COLOR_CSC_MODE_YUV601_TO_RGB709;
+
 	return plane_color_ctl;
 }
 

drivers/gpu/drm/i915/intel_drv.h

@@ -1589,6 +1589,7 @@ u32 glk_plane_color_ctl(const struct intel_crtc_state *crtc_state,
 			const struct intel_plane_state *plane_state);
 u32 skl_plane_ctl(const struct intel_crtc_state *crtc_state,
 		  const struct intel_plane_state *plane_state);
+u32 glk_color_ctl(const struct intel_plane_state *plane_state);
 u32 skl_plane_stride(const struct drm_framebuffer *fb, int plane,
 		     unsigned int rotation);
 int skl_check_plane_surface(const struct intel_crtc_state *crtc_state,
@@ -2014,6 +2015,7 @@ bool intel_sdvo_init(struct drm_i915_private *dev_priv,
 
 
 /* intel_sprite.c */
+bool intel_format_is_yuv(u32 format);
 int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
 			     int usecs);
 struct intel_plane *intel_sprite_plane_create(struct drm_i915_private *dev_priv,

drivers/gpu/drm/i915/intel_sprite.c

@@ -41,8 +41,7 @@
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
 
-static bool
-format_is_yuv(uint32_t format)
+bool intel_format_is_yuv(u32 format)
 {
 	switch (format) {
 	case DRM_FORMAT_YUYV:
@@ -266,6 +265,7 @@ skl_update_plane(struct intel_plane *plane,
 	if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv))
 		I915_WRITE_FW(PLANE_COLOR_CTL(pipe, plane_id),
 			      plane_state->color_ctl);
+
 	if (key->flags) {
 		I915_WRITE_FW(PLANE_KEYVAL(pipe, plane_id), key->min_value);
 		I915_WRITE_FW(PLANE_KEYMAX(pipe, plane_id), key->max_value);
@@ -354,7 +354,7 @@ chv_update_csc(const struct intel_plane_state *plane_state)
 	enum plane_id plane_id = plane->id;
 
 	/* Seems RGB data bypasses the CSC always */
-	if (!format_is_yuv(fb->format->format))
+	if (!intel_format_is_yuv(fb->format->format))
 		return;
 
 	/*
@@ -399,7 +399,7 @@ vlv_update_clrc(const struct intel_plane_state *plane_state)
 	enum plane_id plane_id = plane->id;
 	int contrast, brightness, sh_scale, sh_sin, sh_cos;
 
-	if (format_is_yuv(fb->format->format)) {
+	if (intel_format_is_yuv(fb->format->format)) {
 		/*
 		 * Expand limited range to full range:
 		 * Contrast is applied first and is used to expand Y range.
@@ -1024,7 +1024,7 @@ intel_check_sprite_plane(struct intel_plane *plane,
 		src_y = src->y1 >> 16;
 		src_h = drm_rect_height(src) >> 16;
 
-		if (format_is_yuv(fb->format->format)) {
+		if (intel_format_is_yuv(fb->format->format)) {
 			src_x &= ~1;
 			src_w &= ~1;