drm/radeon: Add support for programming the FMT blocks

The FMT blocks control how data is sent from the backend
of the display pipe to to monitor.  Proper set up of the
FMT blocks are required for 30bpp formats.  Additionally,
dithering can be enabled on for better display with 18 and
24bpp displays.  The exception is LVDS/eDP which atom
takes care of in the SelectCRTC_Source table.  For now
just enable truncation until we test dithering more.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/cikd.h b/drivers/gpu/drm/radeon/cikd.h
index 203d2a0..74172cc 100644
--- a/drivers/gpu/drm/radeon/cikd.h
+++ b/drivers/gpu/drm/radeon/cikd.h
@@ -906,6 +906,39 @@
 #define DPG_PIPE_STUTTER_CONTROL                          0x6cd4
 #       define STUTTER_ENABLE                             (1 << 0)
 
+/* DCE8 FMT blocks */
+#define FMT_DYNAMIC_EXP_CNTL                 0x6fb4
+#       define FMT_DYNAMIC_EXP_EN            (1 << 0)
+#       define FMT_DYNAMIC_EXP_MODE          (1 << 4)
+        /* 0 = 10bit -> 12bit, 1 = 8bit -> 12bit */
+#define FMT_CONTROL                          0x6fb8
+#       define FMT_PIXEL_ENCODING            (1 << 16)
+        /* 0 = RGB 4:4:4 or YCbCr 4:4:4, 1 = YCbCr 4:2:2 */
+#define FMT_BIT_DEPTH_CONTROL                0x6fc8
+#       define FMT_TRUNCATE_EN               (1 << 0)
+#       define FMT_TRUNCATE_MODE             (1 << 1)
+#       define FMT_TRUNCATE_DEPTH(x)         ((x) << 4) /* 0 - 18bpp, 1 - 24bpp, 2 - 30bpp */
+#       define FMT_SPATIAL_DITHER_EN         (1 << 8)
+#       define FMT_SPATIAL_DITHER_MODE(x)    ((x) << 9)
+#       define FMT_SPATIAL_DITHER_DEPTH(x)   ((x) << 11) /* 0 - 18bpp, 1 - 24bpp, 2 - 30bpp */
+#       define FMT_FRAME_RANDOM_ENABLE       (1 << 13)
+#       define FMT_RGB_RANDOM_ENABLE         (1 << 14)
+#       define FMT_HIGHPASS_RANDOM_ENABLE    (1 << 15)
+#       define FMT_TEMPORAL_DITHER_EN        (1 << 16)
+#       define FMT_TEMPORAL_DITHER_DEPTH(x)  ((x) << 17) /* 0 - 18bpp, 1 - 24bpp, 2 - 30bpp */
+#       define FMT_TEMPORAL_DITHER_OFFSET(x) ((x) << 21)
+#       define FMT_TEMPORAL_LEVEL            (1 << 24)
+#       define FMT_TEMPORAL_DITHER_RESET     (1 << 25)
+#       define FMT_25FRC_SEL(x)              ((x) << 26)
+#       define FMT_50FRC_SEL(x)              ((x) << 28)
+#       define FMT_75FRC_SEL(x)              ((x) << 30)
+#define FMT_CLAMP_CONTROL                    0x6fe4
+#       define FMT_CLAMP_DATA_EN             (1 << 0)
+#       define FMT_CLAMP_COLOR_FORMAT(x)     ((x) << 16)
+#       define FMT_CLAMP_6BPC                0
+#       define FMT_CLAMP_8BPC                1
+#       define FMT_CLAMP_10BPC               2
+
 #define	GRBM_CNTL					0x8000
 #define		GRBM_READ_TIMEOUT(x)				((x) << 0)