drm/amd/display: Support long vblank feature

[WHY]
We want to support low hz case, but the original
vtotal/vtotal_min/vtotal_max can't support more
than 0x7FFF.

[HOW]
We use the 2 HW reg to contorl long vblank case.
1. OTG_V_COUNT_STOP_CONTROL -> vcount_stop
2. OTG_V_COUNT_STOP_CONTROL2 -> vcount_stop_timer

vcount_stop define from which line we stop using vcount
and start using vcount2.
vcount_stop_timer define how long we use vcount2.

Ex:
Vtotal = 7
OTG_V_COUNT_STOP_CONTROL = 4
OTG_V_COUNT_STOP_CONTROL2 = 5

time    : 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
vcount  : 0, 1, 2, 3, -  -  -  -  -  4,  5,  6
vcount2 :             0, 1, 2, 3, 4,

Reviewed-by: Jun Lei <jun.lei@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: ChunTao Tso <chuntao.tso@amd.com>
Signed-off-by: Robin Chen<robin.chen@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 5c8b0183959c..64ab99628125 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -386,6 +386,30 @@ static void dc_perf_trace_destroy(struct dc_perf_trace **perf_trace)
 	*perf_trace = NULL;
 }
 
+static bool set_long_vtotal(struct dc *dc, struct dc_stream_state *stream, struct dc_crtc_timing_adjust *adjust)
+{
+	if (!dc || !stream || !adjust)
+		return false;
+
+	if (!dc->current_state)
+		return false;
+
+	int i;
+
+	for (i = 0; i < MAX_PIPES; i++) {
+		struct pipe_ctx *pipe = &dc->current_state->res_ctx.pipe_ctx[i];
+
+		if (pipe->stream == stream && pipe->stream_res.tg) {
+			if (dc->hwss.set_long_vtotal)
+				dc->hwss.set_long_vtotal(&pipe, 1, adjust->v_total_min, adjust->v_total_max);
+
+			return true;
+		}
+	}
+
+	return false;
+}
+
 /**
  *  dc_stream_adjust_vmin_vmax - look up pipe context & update parts of DRR
  *  @dc:     dc reference
@@ -420,6 +444,15 @@ bool dc_stream_adjust_vmin_vmax(struct dc *dc,
 	stream->adjust.v_total_mid = adjust->v_total_mid;
 	stream->adjust.v_total_mid_frame_num = adjust->v_total_mid_frame_num;
 	stream->adjust.v_total_min = adjust->v_total_min;
+	stream->adjust.allow_otg_v_count_halt = adjust->allow_otg_v_count_halt;
+
+	if (dc->caps.max_v_total != 0 &&
+		(adjust->v_total_max > dc->caps.max_v_total || adjust->v_total_min > dc->caps.max_v_total)) {
+		if (adjust->allow_otg_v_count_halt)
+			return set_long_vtotal(dc, stream, adjust);
+		else
+			return false;
+	}
 
 	for (i = 0; i < MAX_PIPES; i++) {
 		struct pipe_ctx *pipe = &dc->current_state->res_ctx.pipe_ctx[i];