drm/amd/display: Update DTBCLK for DCN32

[Why&How]
- Implement interface to program DTBCLK DTO’s
  according to reference DTBCLK returned by PMFW
- This is required because DTO programming
  requires exact DTBCLK reference freq or it could
  result in underflow

Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c

@@ -233,6 +233,32 @@ void dcn32_init_clocks(struct clk_mgr *clk_mgr_base)
 	DC_FP_END();
 }
 
+static void dcn32_update_clocks_update_dtb_dto(struct clk_mgr_internal *clk_mgr,
+			struct dc_state *context,
+			int ref_dtbclk_khz)
+{
+	struct dccg *dccg = clk_mgr->dccg;
+	uint32_t tg_mask = 0;
+	int i;
+
+	for (i = 0; i < clk_mgr->base.ctx->dc->res_pool->pipe_count; i++) {
+		struct pipe_ctx *pipe_ctx = &context->res_ctx.pipe_ctx[i];
+		struct dtbclk_dto_params dto_params = {0};
+
+		/* use mask to program DTO once per tg */
+		if (pipe_ctx->stream_res.tg &&
+				!(tg_mask & (1 << pipe_ctx->stream_res.tg->inst))) {
+			tg_mask |= (1 << pipe_ctx->stream_res.tg->inst);
+
+			dto_params.otg_inst = pipe_ctx->stream_res.tg->inst;
+			dto_params.ref_dtbclk_khz = ref_dtbclk_khz;
+
+			dccg->funcs->set_dtbclk_dto(clk_mgr->dccg, &dto_params);
+			//dccg->funcs->set_audio_dtbclk_dto(clk_mgr->dccg, &dto_params);
+		}
+	}
+}
+
 /* Since DPPCLK request to PMFW needs to be exact (due to DPP DTO programming),
  * update DPPCLK to be the exact frequency that will be set after the DPPCLK
  * divider is updated. This will prevent rounding issues that could cause DPP
@@ -570,6 +596,7 @@ static void dcn32_update_clocks(struct clk_mgr *clk_mgr_base,
 		/* DCCG requires KHz precision for DTBCLK */
 		clk_mgr_base->clks.ref_dtbclk_khz =
 				dcn32_smu_set_hard_min_by_freq(clk_mgr, PPCLK_DTBCLK, khz_to_mhz_ceil(new_clocks->ref_dtbclk_khz));
+		dcn32_update_clocks_update_dtb_dto(clk_mgr, context, clk_mgr_base->clks.ref_dtbclk_khz);
 	}
 
 	if (dc->config.forced_clocks == false || (force_reset && safe_to_lower)) {