drm/amdgpu/display: add support for LVDS (v5)

This adds support for LVDS displays.

v2: add support for spread spectrum, sink detect
v3: clean up enable_lvds_output
v4: fix up link_detect
v5: remove assert on 888 format

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=105880
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -3358,6 +3358,8 @@ static int to_drm_connector_type(enum signal_type st)
 		return DRM_MODE_CONNECTOR_HDMIA;
 	case SIGNAL_TYPE_EDP:
 		return DRM_MODE_CONNECTOR_eDP;
+	case SIGNAL_TYPE_LVDS:
+		return DRM_MODE_CONNECTOR_LVDS;
 	case SIGNAL_TYPE_RGB:
 		return DRM_MODE_CONNECTOR_VGA;
 	case SIGNAL_TYPE_DISPLAY_PORT:

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

@@ -203,6 +203,11 @@ static bool detect_sink(struct dc_link *link, enum dc_connection_type *type)
 	uint32_t is_hpd_high = 0;
 	struct gpio *hpd_pin;
 
+	if (link->connector_signal == SIGNAL_TYPE_LVDS) {
+		*type = dc_connection_single;
+		return true;
+	}
+
 	/* todo: may need to lock gpio access */
 	hpd_pin = get_hpd_gpio(link->ctx->dc_bios, link->link_id, link->ctx->gpio_service);
 	if (hpd_pin == NULL)
@@ -616,6 +621,10 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
 			link->local_sink)
 		return true;
 
+	if (link->connector_signal == SIGNAL_TYPE_LVDS &&
+			link->local_sink)
+		return true;
+
 	prev_sink = link->local_sink;
 	if (prev_sink != NULL) {
 		dc_sink_retain(prev_sink);
@@ -649,6 +658,12 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
 			break;
 		}
 
+		case SIGNAL_TYPE_LVDS: {
+			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
+			sink_caps.signal = SIGNAL_TYPE_LVDS;
+			break;
+		}
+
 		case SIGNAL_TYPE_EDP: {
 			detect_edp_sink_caps(link);
 			sink_caps.transaction_type =
@@ -1087,6 +1102,9 @@ static bool construct(
 					dal_irq_get_rx_source(hpd_gpio);
 		}
 		break;
+	case CONNECTOR_ID_LVDS:
+		link->connector_signal = SIGNAL_TYPE_LVDS;
+		break;
 	default:
 		DC_LOG_WARNING("Unsupported Connector type:%d!\n", link->link_id.id);
 		goto create_fail;
@@ -1920,6 +1938,24 @@ static void enable_link_hdmi(struct pipe_ctx *pipe_ctx)
 		dal_ddc_service_read_scdc_data(link->ddc);
 }
 
+static void enable_link_lvds(struct pipe_ctx *pipe_ctx)
+{
+	struct dc_stream_state *stream = pipe_ctx->stream;
+	struct dc_link *link = stream->sink->link;
+
+	if (stream->phy_pix_clk == 0)
+		stream->phy_pix_clk = stream->timing.pix_clk_khz;
+
+	memset(&stream->sink->link->cur_link_settings, 0,
+			sizeof(struct dc_link_settings));
+
+	link->link_enc->funcs->enable_lvds_output(
+			link->link_enc,
+			pipe_ctx->clock_source->id,
+			stream->phy_pix_clk);
+
+}
+
 /****************************enable_link***********************************/
 static enum dc_status enable_link(
 		struct dc_state *state,
@@ -1943,6 +1979,10 @@ static enum dc_status enable_link(
 		enable_link_hdmi(pipe_ctx);
 		status = DC_OK;
 		break;
+	case SIGNAL_TYPE_LVDS:
+		enable_link_lvds(pipe_ctx);
+		status = DC_OK;
+		break;
 	case SIGNAL_TYPE_VIRTUAL:
 		status = DC_OK;
 		break;
@@ -2492,6 +2532,11 @@ void core_link_enable_stream(
 			(pipe_ctx->stream->signal == SIGNAL_TYPE_DVI_DUAL_LINK) ?
 			true : false);
 
+	if (dc_is_lvds_signal(pipe_ctx->stream->signal))
+		pipe_ctx->stream_res.stream_enc->funcs->lvds_set_stream_attribute(
+			pipe_ctx->stream_res.stream_enc,
+			&stream->timing);
+
 	resource_build_info_frame(pipe_ctx);
 	core_dc->hwss.update_info_frame(pipe_ctx);
 

drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.c

@@ -75,6 +75,11 @@ static const struct spread_spectrum_data *get_ss_data_entry(
 		entrys_num = clk_src->hdmi_ss_params_cnt;
 		break;
 
+	case SIGNAL_TYPE_LVDS:
+		ss_parm = clk_src->lvds_ss_params;
+		entrys_num = clk_src->lvds_ss_params_cnt;
+		break;
+
 	case SIGNAL_TYPE_DISPLAY_PORT:
 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
 	case SIGNAL_TYPE_EDP:
@@ -1184,6 +1189,11 @@ static void ss_info_from_atombios_create(
 		AS_SIGNAL_TYPE_DVI,
 		&clk_src->dvi_ss_params,
 		&clk_src->dvi_ss_params_cnt);
+	get_ss_info_from_atombios(
+		clk_src,
+		AS_SIGNAL_TYPE_LVDS,
+		&clk_src->lvds_ss_params,
+		&clk_src->lvds_ss_params_cnt);
 }
 
 static bool calc_pll_max_vco_construct(

drivers/gpu/drm/amd/display/dc/dce/dce_clock_source.h

@@ -125,6 +125,8 @@ struct dce110_clk_src {
 	uint32_t hdmi_ss_params_cnt;
 	struct spread_spectrum_data *dvi_ss_params;
 	uint32_t dvi_ss_params_cnt;
+	struct spread_spectrum_data *lvds_ss_params;
+	uint32_t lvds_ss_params_cnt;
 
 	uint32_t ext_clk_khz;
 	uint32_t ref_freq_khz;

drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.c

@@ -102,6 +102,7 @@ static const struct link_encoder_funcs dce110_lnk_enc_funcs = {
 	.enable_tmds_output = dce110_link_encoder_enable_tmds_output,
 	.enable_dp_output = dce110_link_encoder_enable_dp_output,
 	.enable_dp_mst_output = dce110_link_encoder_enable_dp_mst_output,
+	.enable_lvds_output = dce110_link_encoder_enable_lvds_output,
 	.disable_output = dce110_link_encoder_disable_output,
 	.dp_set_lane_settings = dce110_link_encoder_dp_set_lane_settings,
 	.dp_set_phy_pattern = dce110_link_encoder_dp_set_phy_pattern,
@@ -814,6 +815,7 @@ bool dce110_link_encoder_validate_output_with_stream(
 					enc110, &stream->timing);
 	break;
 	case SIGNAL_TYPE_EDP:
+	case SIGNAL_TYPE_LVDS:
 		is_valid =
 			(stream->timing.
 				pixel_encoding == PIXEL_ENCODING_RGB) ? true : false;
@@ -955,6 +957,38 @@ void dce110_link_encoder_enable_tmds_output(
 	}
 }
 
+/* TODO: still need depth or just pass in adjusted pixel clock? */
+void dce110_link_encoder_enable_lvds_output(
+	struct link_encoder *enc,
+	enum clock_source_id clock_source,
+	uint32_t pixel_clock)
+{
+	struct dce110_link_encoder *enc110 = TO_DCE110_LINK_ENC(enc);
+	struct bp_transmitter_control cntl = { 0 };
+	enum bp_result result;
+
+	/* Enable the PHY */
+	cntl.connector_obj_id = enc110->base.connector;
+	cntl.action = TRANSMITTER_CONTROL_ENABLE;
+	cntl.engine_id = enc->preferred_engine;
+	cntl.transmitter = enc110->base.transmitter;
+	cntl.pll_id = clock_source;
+	cntl.signal = SIGNAL_TYPE_LVDS;
+	cntl.lanes_number = 4;
+
+	cntl.hpd_sel = enc110->base.hpd_source;
+
+	cntl.pixel_clock = pixel_clock;
+
+	result = link_transmitter_control(enc110, &cntl);
+
+	if (result != BP_RESULT_OK) {
+		DC_LOG_ERROR("%s: Failed to execute VBIOS command table!\n",
+			__func__);
+		BREAK_TO_DEBUGGER();
+	}
+}
+
 /* enables DP PHY output */
 void dce110_link_encoder_enable_dp_output(
 	struct link_encoder *enc,

drivers/gpu/drm/amd/display/dc/dce/dce_link_encoder.h

@@ -225,6 +225,12 @@ void dce110_link_encoder_enable_dp_mst_output(
 	const struct dc_link_settings *link_settings,
 	enum clock_source_id clock_source);
 
+/* enables LVDS PHY output */
+void dce110_link_encoder_enable_lvds_output(
+	struct link_encoder *enc,
+	enum clock_source_id clock_source,
+	uint32_t pixel_clock);
+
 /* disable PHY output */
 void dce110_link_encoder_disable_output(
 	struct link_encoder *enc,

drivers/gpu/drm/amd/display/dc/dce/dce_stream_encoder.c

@@ -674,6 +674,28 @@ static void dce110_stream_encoder_dvi_set_stream_attribute(
 	dce110_stream_encoder_set_stream_attribute_helper(enc110, crtc_timing);
 }
 
+/* setup stream encoder in LVDS mode */
+static void dce110_stream_encoder_lvds_set_stream_attribute(
+	struct stream_encoder *enc,
+	struct dc_crtc_timing *crtc_timing)
+{
+	struct dce110_stream_encoder *enc110 = DCE110STRENC_FROM_STRENC(enc);
+	struct bp_encoder_control cntl = {0};
+
+	cntl.action = ENCODER_CONTROL_SETUP;
+	cntl.engine_id = enc110->base.id;
+	cntl.signal = SIGNAL_TYPE_LVDS;
+	cntl.enable_dp_audio = false;
+	cntl.pixel_clock = crtc_timing->pix_clk_khz;
+	cntl.lanes_number = LANE_COUNT_FOUR;
+
+	if (enc110->base.bp->funcs->encoder_control(
+			enc110->base.bp, &cntl) != BP_RESULT_OK)
+		return;
+
+	ASSERT(crtc_timing->pixel_encoding == PIXEL_ENCODING_RGB);
+}
+
 static void dce110_stream_encoder_set_mst_bandwidth(
 	struct stream_encoder *enc,
 	struct fixed31_32 avg_time_slots_per_mtp)
@@ -1564,6 +1586,8 @@ static const struct stream_encoder_funcs dce110_str_enc_funcs = {
 		dce110_stream_encoder_hdmi_set_stream_attribute,
 	.dvi_set_stream_attribute =
 		dce110_stream_encoder_dvi_set_stream_attribute,
+	.lvds_set_stream_attribute =
+		dce110_stream_encoder_lvds_set_stream_attribute,
 	.set_mst_bandwidth =
 		dce110_stream_encoder_set_mst_bandwidth,
 	.update_hdmi_info_packets =

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

@@ -131,6 +131,9 @@ struct link_encoder_funcs {
 	void (*enable_dp_mst_output)(struct link_encoder *enc,
 		const struct dc_link_settings *link_settings,
 		enum clock_source_id clock_source);
+	void (*enable_lvds_output)(struct link_encoder *enc,
+		enum clock_source_id clock_source,
+		uint32_t pixel_clock);
 	void (*disable_output)(struct link_encoder *link_enc,
 		enum signal_type signal);
 	void (*dp_set_lane_settings)(struct link_encoder *enc,

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

@@ -101,6 +101,10 @@ struct stream_encoder_funcs {
 		struct dc_crtc_timing *crtc_timing,
 		bool is_dual_link);
 
+	void (*lvds_set_stream_attribute)(
+		struct stream_encoder *enc,
+		struct dc_crtc_timing *crtc_timing);
+
 	void (*set_mst_bandwidth)(
 		struct stream_encoder *enc,
 		struct fixed31_32 avg_time_slots_per_mtp);

drivers/gpu/drm/amd/display/include/signal_types.h

@@ -68,6 +68,11 @@ static inline bool dc_is_embedded_signal(enum signal_type signal)
 	return (signal == SIGNAL_TYPE_EDP || signal == SIGNAL_TYPE_LVDS);
 }
 
+static inline bool dc_is_lvds_signal(enum signal_type signal)
+{
+	return (signal == SIGNAL_TYPE_LVDS);
+}
+
 static inline bool dc_is_dvi_signal(enum signal_type signal)
 {
 	switch (signal) {