drm/amd/display: Add DSC support for Navi (v2)

Add support for DCN2 DSC (Display Stream Compression)

HW Blocks:

 +--------++------+       +----------+
 | HUBBUB || HUBP |  <--  | MMHUBBUB |
 +--------++------+       +----------+
        |                     ^
        v                     |
    +--------+            +--------+
    |  DPP   |            |  DWB   |
    +--------+            +--------+
        |
        v                      ^
    +--------+                 |
    |  MPC   |                 |
    +--------+                 |
        |                      |
        v                      |
    +-------+      +-------+   |
    |  OPP  | <--> |  DSC  |   |
    +-------+      +-------+   |
        |                      |
        v                      |
    +--------+                /
    |  OPTC  |  --------------
    +--------+
        |
        v
    +--------+       +--------+
    |  DIO   |       |  DCCG  |
    +--------+       +--------+

v2: rebase (Alex)

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c
index e4b850a2d31f..b3fc71648d16 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c
@@ -1507,10 +1507,28 @@ void dcn10_timing_generator_init(struct optc *optc1)
 	optc1->comb_opp_id = 0xf;
 }
 
+#ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
+/* "Containter" vs. "pixel" is a concept within HW blocks, mostly those closer to the back-end. It works like this:
+ *
+ * - In most of the formats (RGB or YCbCr 4:4:4, 4:2:2 uncompressed and DSC 4:2:2 Simple) pixel rate is the same as
+ *   containter rate.
+ *
+ * - In 4:2:0 (DSC or uncompressed) there are two pixels per container, hence the target container rate has to be
+ *   halved to maintain the correct pixel rate.
+ *
+ * - Unlike 4:2:2 uncompressed, DSC 4:2:2 Native also has two pixels per container (this happens when DSC is applied
+ *   to it) and has to be treated the same as 4:2:0, i.e. target containter rate has to be halved in this case as well.
+ *
+ */
+#endif
 bool optc1_is_two_pixels_per_containter(const struct dc_crtc_timing *timing)
 {
 	bool two_pix = timing->pixel_encoding == PIXEL_ENCODING_YCBCR420;
 
+#ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT
+	two_pix = two_pix || (timing->flags.DSC && timing->pixel_encoding == PIXEL_ENCODING_YCBCR422
+			&& !timing->dsc_cfg.ycbcr422_simple);
+#endif
 	return two_pix;
 }