drm/amd/display: Add seamless boot support for more DIG operation modes

[Why]
When pre-OS firmware enables display support for displays that operate
the DIG in 2 pixels per cycle processing modes the inferred pixel rate
from get_pixel_clk_frequency_100hz does not account for the true pixel
rate since we're outputting 2 per cycle past the stream encoder.

This causes seamless boot validation to abort early.

[How]
Add a new stream encoder function for getting pixels per cycle from the
stream encoder. If the pixels per cycle is greater than 1 and the driver
policy is to enable 2 pixels per cycle for post-OS then allow seamless
boot to continue.
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Duncan Ma <duncan.ma@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -1823,10 +1823,18 @@ bool dc_validate_boot_timing(const struct dc *dc,
 			tg->funcs->get_optc_source(tg,
 						&numOdmPipes, &id_src[0], &id_src[1]);
 
-		if (numOdmPipes == 2)
+		if (numOdmPipes == 2) {
 			pix_clk_100hz *= 2;
-		if (numOdmPipes == 4)
+		} else if (numOdmPipes == 4) {
 			pix_clk_100hz *= 4;
+		} else if (se && se->funcs->get_pixels_per_cycle) {
+			uint32_t pixels_per_cycle = se->funcs->get_pixels_per_cycle(se);
+
+			if (pixels_per_cycle != 1 && !dc->debug.enable_dp_dig_pixel_rate_div_policy)
+				return false;
+
+			pix_clk_100hz *= pixels_per_cycle;
+		}
 
 		// Note: In rare cases, HW pixclk may differ from crtc's pixclk
 		// slightly due to rounding issues in 10 kHz units.

drivers/gpu/drm/amd/display/dc/dio/dcn35/dcn35_dio_stream_encoder.c

@@ -422,6 +422,24 @@ void enc35_enable_fifo(struct stream_encoder *enc)
 	REG_UPDATE(DIG_FIFO_CTRL0, DIG_FIFO_ENABLE, 1);
 }
 
+static uint32_t enc35_get_pixels_per_cycle(struct stream_encoder *enc)
+{
+	struct dcn10_stream_encoder *enc1 = DCN10STRENC_FROM_STRENC(enc);
+	uint32_t value;
+
+	REG_GET(DIG_FIFO_CTRL0, DIG_FIFO_OUTPUT_PIXEL_MODE, &value);
+
+	switch (value) {
+	case 0:
+		return 1;
+	case 1:
+		return 2;
+	default:
+		ASSERT_CRITICAL(false);
+		return 1;
+	}
+}
+
 static const struct stream_encoder_funcs dcn35_str_enc_funcs = {
 	.dp_set_odm_combine =
 		enc314_dp_set_odm_combine,
@@ -474,6 +492,7 @@ static const struct stream_encoder_funcs dcn35_str_enc_funcs = {
 	.disable_fifo = enc35_disable_fifo,
 	.is_fifo_enabled = enc35_is_fifo_enabled,
 	.map_stream_to_link = enc35_stream_encoder_map_to_link,
+	.get_pixels_per_cycle = enc35_get_pixels_per_cycle,
 };
 
 void dcn35_dio_stream_encoder_construct(

drivers/gpu/drm/amd/display/dc/inc/hw/stream_encoder.h

@@ -273,6 +273,7 @@ struct stream_encoder_funcs {
 	void (*disable_fifo)(struct stream_encoder *enc);
 	bool (*is_fifo_enabled)(struct stream_encoder *enc);
 	void (*map_stream_to_link)(struct stream_encoder *enc, uint32_t stream_enc_inst, uint32_t link_enc_inst);
+	uint32_t (*get_pixels_per_cycle)(struct stream_encoder *enc);
 };
 
 struct hpo_dp_stream_encoder_state {