drm/amd/display: merge dc_link.h into dc.h and dc_types.h

[why]
Remove the need to include dc_link.h separately. dc.h should contain
everything needed on DM side.

[How]
Merge dc_link.h into dc.h and dc_types.h so DM only needs to include
dc.h to use all link public functions.

Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

33 files changed, 978 insertions, 288 deletions

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index cfbde4fde852..824cfc4a0293 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2273,7 +2273,7 @@ static int dm_late_init(void *handle)
 		struct dc_link *edp_links[MAX_NUM_EDP];
 		int edp_num;
 
-		get_edp_links(adev->dm.dc, edp_links, &edp_num);
+		dc_get_edp_links(adev->dm.dc, edp_links, &edp_num);
 		for (i = 0; i < edp_num; i++) {
 			if (!dmub_init_abm_config(adev->dm.dc->res_pool, params, i))
 				return -EINVAL;
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 09a3efa517da..4a5dae578d97 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -724,7 +724,7 @@ static ssize_t dp_phy_test_pattern_debugfs_write(struct file *f, const char __us
 	for (i = 0; i < (unsigned int)(link_training_settings.link_settings.lane_count); i++)
 		link_training_settings.hw_lane_settings[i] = link->cur_lane_setting[i];
 
-	dc_link_set_test_pattern(
+	dc_link_dp_set_test_pattern(
 		link,
 		test_pattern,
 		DP_TEST_PATTERN_COLOR_SPACE_RGB,
diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/clk_mgr.c
index 69691daf4dbb..73a45ec27f90 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/clk_mgr.c
@@ -104,7 +104,7 @@ void clk_mgr_exit_optimized_pwr_state(const struct dc *dc, struct clk_mgr *clk_m
 	int edp_num;
 	unsigned int panel_inst;
 
-	get_edp_links(dc, edp_links, &edp_num);
+	dc_get_edp_links(dc, edp_links, &edp_num);
 	if (dc->hwss.exit_optimized_pwr_state)
 		dc->hwss.exit_optimized_pwr_state(dc, dc->current_state);
 
@@ -129,7 +129,7 @@ void clk_mgr_optimize_pwr_state(const struct dc *dc, struct clk_mgr *clk_mgr)
 	int edp_num;
 	unsigned int panel_inst;
 
-	get_edp_links(dc, edp_links, &edp_num);
+	dc_get_edp_links(dc, edp_links, &edp_num);
 	if (edp_num) {
 		for (panel_inst = 0; panel_inst < edp_num; panel_inst++) {
 			edp_link = edp_links[panel_inst];
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index 1c218c526650..d406d7b74c6c 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -53,7 +53,6 @@
 #include "link_encoder.h"
 #include "link_enc_cfg.h"
 
-#include "dc_link.h"
 #include "link.h"
 #include "dm_helpers.h"
 #include "mem_input.h"
@@ -1298,7 +1297,7 @@ static void detect_edp_presence(struct dc *dc)
 	int i;
 	int edp_num;
 
-	get_edp_links(dc, edp_links, &edp_num);
+	dc_get_edp_links(dc, edp_links, &edp_num);
 	if (!edp_num)
 		return;
 
@@ -4317,157 +4316,6 @@ bool dc_is_dmcu_initialized(struct dc *dc)
 	return false;
 }
 
-bool dc_is_oem_i2c_device_present(
-	struct dc *dc,
-	size_t slave_address)
-{
-	if (dc->res_pool->oem_device)
-		return dce_i2c_oem_device_present(
-			dc->res_pool,
-			dc->res_pool->oem_device,
-			slave_address);
-
-	return false;
-}
-
-bool dc_submit_i2c(
-		struct dc *dc,
-		uint32_t link_index,
-		struct i2c_command *cmd)
-{
-
-	struct dc_link *link = dc->links[link_index];
-	struct ddc_service *ddc = link->ddc;
-	return dce_i2c_submit_command(
-		dc->res_pool,
-		ddc->ddc_pin,
-		cmd);
-}
-
-bool dc_submit_i2c_oem(
-		struct dc *dc,
-		struct i2c_command *cmd)
-{
-	struct ddc_service *ddc = dc->res_pool->oem_device;
-	if (ddc)
-		return dce_i2c_submit_command(
-			dc->res_pool,
-			ddc->ddc_pin,
-			cmd);
-
-	return false;
-}
-
-static bool link_add_remote_sink_helper(struct dc_link *dc_link, struct dc_sink *sink)
-{
-	if (dc_link->sink_count >= MAX_SINKS_PER_LINK) {
-		BREAK_TO_DEBUGGER();
-		return false;
-	}
-
-	dc_sink_retain(sink);
-
-	dc_link->remote_sinks[dc_link->sink_count] = sink;
-	dc_link->sink_count++;
-
-	return true;
-}
-
-/*
- * dc_link_add_remote_sink() - Create a sink and attach it to an existing link
- *
- * EDID length is in bytes
- */
-struct dc_sink *dc_link_add_remote_sink(
-		struct dc_link *link,
-		const uint8_t *edid,
-		int len,
-		struct dc_sink_init_data *init_data)
-{
-	struct dc_sink *dc_sink;
-	enum dc_edid_status edid_status;
-
-	if (len > DC_MAX_EDID_BUFFER_SIZE) {
-		dm_error("Max EDID buffer size breached!\n");
-		return NULL;
-	}
-
-	if (!init_data) {
-		BREAK_TO_DEBUGGER();
-		return NULL;
-	}
-
-	if (!init_data->link) {
-		BREAK_TO_DEBUGGER();
-		return NULL;
-	}
-
-	dc_sink = dc_sink_create(init_data);
-
-	if (!dc_sink)
-		return NULL;
-
-	memmove(dc_sink->dc_edid.raw_edid, edid, len);
-	dc_sink->dc_edid.length = len;
-
-	if (!link_add_remote_sink_helper(
-			link,
-			dc_sink))
-		goto fail_add_sink;
-
-	edid_status = dm_helpers_parse_edid_caps(
-			link,
-			&dc_sink->dc_edid,
-			&dc_sink->edid_caps);
-
-	/*
-	 * Treat device as no EDID device if EDID
-	 * parsing fails
-	 */
-	if (edid_status != EDID_OK && edid_status != EDID_PARTIAL_VALID) {
-		dc_sink->dc_edid.length = 0;
-		dm_error("Bad EDID, status%d!\n", edid_status);
-	}
-
-	return dc_sink;
-
-fail_add_sink:
-	dc_sink_release(dc_sink);
-	return NULL;
-}
-
-/*
- * dc_link_remove_remote_sink() - Remove a remote sink from a dc_link
- *
- * Note that this just removes the struct dc_sink - it doesn't
- * program hardware or alter other members of dc_link
- */
-void dc_link_remove_remote_sink(struct dc_link *link, struct dc_sink *sink)
-{
-	int i;
-
-	if (!link->sink_count) {
-		BREAK_TO_DEBUGGER();
-		return;
-	}
-
-	for (i = 0; i < link->sink_count; i++) {
-		if (link->remote_sinks[i] == sink) {
-			dc_sink_release(sink);
-			link->remote_sinks[i] = NULL;
-
-			/* shrink array to remove empty place */
-			while (i < link->sink_count - 1) {
-				link->remote_sinks[i] = link->remote_sinks[i+1];
-				i++;
-			}
-			link->remote_sinks[i] = NULL;
-			link->sink_count--;
-			return;
-		}
-	}
-}
-
 void get_clock_requirements_for_state(struct dc_state *state, struct AsicStateEx *info)
 {
 	info->displayClock				= (unsigned int)state->bw_ctx.bw.dcn.clk.dispclk_khz;
@@ -4990,7 +4838,7 @@ void dc_notify_vsync_int_state(struct dc *dc, struct dc_stream_state *stream, bo
 		return;
 	}
 
-	get_edp_links(dc, edp_links, &edp_num);
+	dc_get_edp_links(dc, edp_links, &edp_num);
 
 	/* Determine panel inst */
 	for (i = 0; i < edp_num; i++) {
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_exports.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_exports.c
index a951e10416ee..862cb0f93b7d 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_exports.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_exports.c
@@ -34,6 +34,49 @@
  * in this file which calls link functions.
  */
 #include "link.h"
+#include "dce/dce_i2c.h"
+struct dc_link *dc_get_link_at_index(struct dc *dc, uint32_t link_index)
+{
+	return dc->links[link_index];
+}
+
+void dc_get_edp_links(const struct dc *dc,
+		struct dc_link **edp_links,
+		int *edp_num)
+{
+	int i;
+
+	*edp_num = 0;
+	for (i = 0; i < dc->link_count; i++) {
+		// report any eDP links, even unconnected DDI's
+		if (!dc->links[i])
+			continue;
+		if (dc->links[i]->connector_signal == SIGNAL_TYPE_EDP) {
+			edp_links[*edp_num] = dc->links[i];
+			if (++(*edp_num) == MAX_NUM_EDP)
+				return;
+		}
+	}
+}
+
+bool dc_get_edp_link_panel_inst(const struct dc *dc,
+		const struct dc_link *link,
+		unsigned int *inst_out)
+{
+	struct dc_link *edp_links[MAX_NUM_EDP];
+	int edp_num, i;
+
+	*inst_out = 0;
+	if (link->connector_signal != SIGNAL_TYPE_EDP)
+		return false;
+	dc_get_edp_links(dc, edp_links, &edp_num);
+	for (i = 0; i < edp_num; i++) {
+		if (link == edp_links[i])
+			break;
+		(*inst_out)++;
+	}
+	return true;
+}
 
 bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
 {
@@ -101,3 +144,47 @@ bool dc_link_update_dsc_config(struct pipe_ctx *pipe_ctx)
 {
 	return link_update_dsc_config(pipe_ctx);
 }
+
+bool dc_is_oem_i2c_device_present(
+	struct dc *dc,
+	size_t slave_address)
+{
+	if (dc->res_pool->oem_device)
+		return dce_i2c_oem_device_present(
+			dc->res_pool,
+			dc->res_pool->oem_device,
+			slave_address);
+
+	return false;
+}
+
+bool dc_submit_i2c(
+		struct dc *dc,
+		uint32_t link_index,
+		struct i2c_command *cmd)
+{
+
+	struct dc_link *link = dc->links[link_index];
+	struct ddc_service *ddc = link->ddc;
+
+	return dce_i2c_submit_command(
+		dc->res_pool,
+		ddc->ddc_pin,
+		cmd);
+}
+
+bool dc_submit_i2c_oem(
+		struct dc *dc,
+		struct i2c_command *cmd)
+{
+	struct ddc_service *ddc = dc->res_pool->oem_device;
+
+	if (ddc)
+		return dce_i2c_submit_command(
+			dc->res_pool,
+			ddc->ddc_pin,
+			cmd);
+
+	return false;
+}
+
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 8a62f3e93e35..c84554933dc2 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -1380,8 +1380,159 @@ struct dc_plane_state *dc_get_surface_for_mpcc(struct dc *dc,
 uint32_t dc_get_opp_for_plane(struct dc *dc, struct dc_plane_state *plane);
 
 /* Link Interfaces */
-/* TODO: remove this after resolving external dependencies */
-#include "dc_link.h"
+/*
+ * A link contains one or more sinks and their connected status.
+ * The currently active signal type (HDMI, DP-SST, DP-MST) is also reported.
+ */
+struct dc_link {
+	struct dc_sink *remote_sinks[MAX_SINKS_PER_LINK];
+	unsigned int sink_count;
+	struct dc_sink *local_sink;
+	unsigned int link_index;
+	enum dc_connection_type type;
+	enum signal_type connector_signal;
+	enum dc_irq_source irq_source_hpd;
+	enum dc_irq_source irq_source_hpd_rx;/* aka DP Short Pulse  */
+
+	bool is_hpd_filter_disabled;
+	bool dp_ss_off;
+
+	/**
+	 * @link_state_valid:
+	 *
+	 * If there is no link and local sink, this variable should be set to
+	 * false. Otherwise, it should be set to true; usually, the function
+	 * core_link_enable_stream sets this field to true.
+	 */
+	bool link_state_valid;
+	bool aux_access_disabled;
+	bool sync_lt_in_progress;
+	bool skip_stream_reenable;
+	bool is_internal_display;
+	/** @todo Rename. Flag an endpoint as having a programmable mapping to a DIG encoder. */
+	bool is_dig_mapping_flexible;
+	bool hpd_status; /* HPD status of link without physical HPD pin. */
+	bool is_hpd_pending; /* Indicates a new received hpd */
+	bool is_automated; /* Indicates automated testing */
+
+	bool edp_sink_present;
+
+	struct dp_trace dp_trace;
+
+	/* caps is the same as reported_link_cap. link_traing use
+	 * reported_link_cap. Will clean up.  TODO
+	 */
+	struct dc_link_settings reported_link_cap;
+	struct dc_link_settings verified_link_cap;
+	struct dc_link_settings cur_link_settings;
+	struct dc_lane_settings cur_lane_setting[LANE_COUNT_DP_MAX];
+	struct dc_link_settings preferred_link_setting;
+	/* preferred_training_settings are override values that
+	 * come from DM. DM is responsible for the memory
+	 * management of the override pointers.
+	 */
+	struct dc_link_training_overrides preferred_training_settings;
+	struct dp_audio_test_data audio_test_data;
+
+	uint8_t ddc_hw_inst;
+
+	uint8_t hpd_src;
+
+	uint8_t link_enc_hw_inst;
+	/* DIG link encoder ID. Used as index in link encoder resource pool.
+	 * For links with fixed mapping to DIG, this is not changed after dc_link
+	 * object creation.
+	 */
+	enum engine_id eng_id;
+
+	bool test_pattern_enabled;
+	union compliance_test_state compliance_test_state;
+
+	void *priv;
+
+	struct ddc_service *ddc;
+
+	bool aux_mode;
+
+	/* Private to DC core */
+
+	const struct dc *dc;
+
+	struct dc_context *ctx;
+
+	struct panel_cntl *panel_cntl;
+	struct link_encoder *link_enc;
+	struct graphics_object_id link_id;
+	/* Endpoint type distinguishes display endpoints which do not have entries
+	 * in the BIOS connector table from those that do. Helps when tracking link
+	 * encoder to display endpoint assignments.
+	 */
+	enum display_endpoint_type ep_type;
+	union ddi_channel_mapping ddi_channel_mapping;
+	struct connector_device_tag_info device_tag;
+	struct dpcd_caps dpcd_caps;
+	uint32_t dongle_max_pix_clk;
+	unsigned short chip_caps;
+	unsigned int dpcd_sink_count;
+#if defined(CONFIG_DRM_AMD_DC_HDCP)
+	struct hdcp_caps hdcp_caps;
+#endif
+	enum edp_revision edp_revision;
+	union dpcd_sink_ext_caps dpcd_sink_ext_caps;
+
+	struct psr_settings psr_settings;
+
+	/* Drive settings read from integrated info table */
+	struct dc_lane_settings bios_forced_drive_settings;
+
+	/* Vendor specific LTTPR workaround variables */
+	uint8_t vendor_specific_lttpr_link_rate_wa;
+	bool apply_vendor_specific_lttpr_link_rate_wa;
+
+	/* MST record stream using this link */
+	struct link_flags {
+		bool dp_keep_receiver_powered;
+		bool dp_skip_DID2;
+		bool dp_skip_reset_segment;
+		bool dp_skip_fs_144hz;
+		bool dp_mot_reset_segment;
+		/* Some USB4 docks do not handle turning off MST DSC once it has been enabled. */
+		bool dpia_mst_dsc_always_on;
+		/* Forced DPIA into TBT3 compatibility mode. */
+		bool dpia_forced_tbt3_mode;
+		bool dongle_mode_timing_override;
+	} wa_flags;
+	struct link_mst_stream_allocation_table mst_stream_alloc_table;
+
+	struct dc_link_status link_status;
+	struct dprx_states dprx_states;
+
+	struct gpio *hpd_gpio;
+	enum dc_link_fec_state fec_state;
+	bool link_powered_externally;	// Used to bypass hardware sequencing delays when panel is powered down forcibly
+
+	struct dc_panel_config panel_config;
+	struct phy_state phy_state;
+	// BW ALLOCATON USB4 ONLY
+	struct dc_dpia_bw_alloc dpia_bw_alloc_config;
+};
+
+/* Return an enumerated dc_link.
+ * dc_link order is constant and determined at
+ * boot time.  They cannot be created or destroyed.
+ * Use dc_get_caps() to get number of links.
+ */
+struct dc_link *dc_get_link_at_index(struct dc *dc, uint32_t link_index);
+
+/* Return instance id of the edp link. Inst 0 is primary edp link. */
+bool dc_get_edp_link_panel_inst(const struct dc *dc,
+		const struct dc_link *link,
+		unsigned int *inst_out);
+
+/* Return an array of link pointers to edp links. */
+void dc_get_edp_links(const struct dc *dc,
+		struct dc_link **edp_links,
+		int *edp_num);
 
 /* The function initiates detection handshake over the given link. It first
  * determines if there are display connections over the link. If so it initiates
@@ -1405,6 +1556,38 @@ uint32_t dc_get_opp_for_plane(struct dc *dc, struct dc_plane_state *plane);
  */
 bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason);
 
+struct dc_sink_init_data;
+
+/* When link connection type is dc_connection_mst_branch, remote sink can be
+ * added to the link. The interface creates a remote sink and associates it with
+ * current link. The sink will be retained by link until remove remote sink is
+ * called.
+ *
+ * @dc_link - link the remote sink will be added to.
+ * @edid - byte array of EDID raw data.
+ * @len - size of the edid in byte
+ * @init_data -
+ */
+struct dc_sink *dc_link_add_remote_sink(
+		struct dc_link *dc_link,
+		const uint8_t *edid,
+		int len,
+		struct dc_sink_init_data *init_data);
+
+/* Remove remote sink from a link with dc_connection_mst_branch connection type.
+ * @link - link the sink should be removed from
+ * @sink - sink to be removed.
+ */
+void dc_link_remove_remote_sink(
+	struct dc_link *link,
+	struct dc_sink *sink);
+
+/* Enable HPD interrupt handler for a given link */
+void dc_link_enable_hpd(const struct dc_link *link);
+
+/* Disable HPD interrupt handler for a given link */
+void dc_link_disable_hpd(const struct dc_link *link);
+
 /* determine if there is a sink connected to the link
  *
  * @type - dc_connection_single if connected, dc_connection_none otherwise.
@@ -1418,15 +1601,119 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason);
 bool dc_link_detect_connection_type(struct dc_link *link,
 		enum dc_connection_type *type);
 
+/* query current hpd pin value
+ * return - true HPD is asserted (HPD high), false otherwise (HPD low)
+ *
+ */
+bool dc_link_get_hpd_state(struct dc_link *dc_link);
+
 /* Getter for cached link status from given link */
 const struct dc_link_status *dc_link_get_status(const struct dc_link *link);
 
+/* enable/disable hardware HPD filter.
+ *
+ * @link - The link the HPD pin is associated with.
+ * @enable = true - enable hardware HPD filter. HPD event will only queued to irq
+ * handler once after no HPD change has been detected within dc default HPD
+ * filtering interval since last HPD event. i.e if display keeps toggling hpd
+ * pulses within default HPD interval, no HPD event will be received until HPD
+ * toggles have stopped. Then HPD event will be queued to irq handler once after
+ * dc default HPD filtering interval since last HPD event.
+ *
+ * @enable = false - disable hardware HPD filter. HPD event will be queued
+ * immediately to irq handler after no HPD change has been detected within
+ * IRQ_HPD (aka HPD short pulse) interval (i.e 2ms).
+ */
+void dc_link_enable_hpd_filter(struct dc_link *link, bool enable);
+
+/* submit i2c read/write payloads through ddc channel
+ * @link_index - index to a link with ddc in i2c mode
+ * @cmd - i2c command structure
+ * return - true if success, false otherwise.
+ */
+bool dc_submit_i2c(
+		struct dc *dc,
+		uint32_t link_index,
+		struct i2c_command *cmd);
+
+/* submit i2c read/write payloads through oem channel
+ * @link_index - index to a link with ddc in i2c mode
+ * @cmd - i2c command structure
+ * return - true if success, false otherwise.
+ */
+bool dc_submit_i2c_oem(
+		struct dc *dc,
+		struct i2c_command *cmd);
+
+enum aux_return_code_type;
+/* Attempt to transfer the given aux payload. This function does not perform
+ * retries or handle error states. The reply is returned in the payload->reply
+ * and the result through operation_result. Returns the number of bytes
+ * transferred,or -1 on a failure.
+ */
+int dc_link_aux_transfer_raw(struct ddc_service *ddc,
+		struct aux_payload *payload,
+		enum aux_return_code_type *operation_result);
+
+bool dc_is_oem_i2c_device_present(
+	struct dc *dc,
+	size_t slave_address
+);
+
 #ifdef CONFIG_DRM_AMD_DC_HDCP
+
 /* return true if the connected receiver supports the hdcp version */
 bool dc_link_is_hdcp14(struct dc_link *link, enum signal_type signal);
 bool dc_link_is_hdcp22(struct dc_link *link, enum signal_type signal);
 #endif
 
+/* Notify DC about DP RX Interrupt (aka DP IRQ_HPD).
+ *
+ * TODO - When defer_handling is true the function will have a different purpose.
+ * It no longer does complete hpd rx irq handling. We should create a separate
+ * interface specifically for this case.
+ *
+ * Return:
+ * true - Downstream port status changed. DM should call DC to do the
+ * detection.
+ * false - no change in Downstream port status. No further action required
+ * from DM.
+ */
+bool dc_link_handle_hpd_rx_irq(struct dc_link *dc_link,
+		union hpd_irq_data *hpd_irq_dpcd_data, bool *out_link_loss,
+		bool defer_handling, bool *has_left_work);
+/* handle DP specs define test automation sequence*/
+void dc_link_dp_handle_automated_test(struct dc_link *link);
+
+/* handle DP Link loss sequence and try to recover RX link loss with best
+ * effort
+ */
+void dc_link_dp_handle_link_loss(struct dc_link *link);
+
+/* Determine if hpd rx irq should be handled or ignored
+ * return true - hpd rx irq should be handled.
+ * return false - it is safe to ignore hpd rx irq event
+ */
+bool dc_link_dp_allow_hpd_rx_irq(const struct dc_link *link);
+
+/* Determine if link loss is indicated with a given hpd_irq_dpcd_data.
+ * @link - link the hpd irq data associated with
+ * @hpd_irq_dpcd_data - input hpd irq data
+ * return - true if hpd irq data indicates a link lost
+ */
+bool dc_link_check_link_loss_status(struct dc_link *link,
+		union hpd_irq_data *hpd_irq_dpcd_data);
+
+/* Read hpd rx irq data from a given link
+ * @link - link where the hpd irq data should be read from
+ * @irq_data - output hpd irq data
+ * return - DC_OK if hpd irq data is read successfully, otherwise hpd irq data
+ * read has failed.
+ */
+enum dc_status dc_link_dp_read_hpd_rx_irq_data(
+	struct dc_link *link,
+	union hpd_irq_data *irq_data);
+
 /* The function clears recorded DP RX states in the link. DM should call this
  * function when it is resuming from S3 power state to previously connected links.
  *
@@ -1494,6 +1781,268 @@ void dc_restore_link_res_map(const struct dc *dc, uint32_t *map);
  * interface i.e stream_update->dsc_config
  */
 bool dc_link_update_dsc_config(struct pipe_ctx *pipe_ctx);
+
+/* translate a raw link rate data to bandwidth in kbps */
+uint32_t dc_link_bw_kbps_from_raw_frl_link_rate_data(uint8_t bw);
+
+/* determine the optimal bandwidth given link and required bw.
+ * @link - current detected link
+ * @req_bw - requested bandwidth in kbps
+ * @link_settings - returned most optimal link settings that can fit the
+ * requested bandwidth
+ * return - false if link can't support requested bandwidth, true if link
+ * settings is found.
+ */
+bool dc_link_decide_edp_link_settings(struct dc_link *link,
+		struct dc_link_settings *link_settings,
+		uint32_t req_bw);
+
+/* return the max dp link settings can be driven by the link without considering
+ * connected RX device and its capability
+ */
+bool dc_link_dp_get_max_link_enc_cap(const struct dc_link *link,
+		struct dc_link_settings *max_link_enc_cap);
+
+/* determine when the link is driving MST mode, what DP link channel coding
+ * format will be used. The decision will remain unchanged until next HPD event.
+ *
+ * @link -  a link with DP RX connection
+ * return - if stream is committed to this link with MST signal type, type of
+ * channel coding format dc will choose.
+ */
+enum dp_link_encoding dc_link_dp_mst_decide_link_encoding_format(
+		const struct dc_link *link);
+
+/* get max dp link settings the link can enable with all things considered. (i.e
+ * TX/RX/Cable capabilities and dp override policies.
+ *
+ * @link - a link with DP RX connection
+ * return - max dp link settings the link can enable.
+ *
+ */
+const struct dc_link_settings *dc_link_get_link_cap(const struct dc_link *link);
+
+/* Check if a RX (ex. DP sink, MST hub, passive or active dongle) is connected
+ * to a link with dp connector signal type.
+ * @link - a link with dp connector signal type
+ * return - true if connected, false otherwise
+ */
+bool dc_link_is_dp_sink_present(struct dc_link *link);
+
+/* Force DP lane settings update to main-link video signal and notify the change
+ * to DP RX via DPCD. This is a debug interface used for video signal integrity
+ * tuning purpose. The interface assumes link has already been enabled with DP
+ * signal.
+ *
+ * @lt_settings - a container structure with desired hw_lane_settings
+ */
+void dc_link_set_drive_settings(struct dc *dc,
+				struct link_training_settings *lt_settings,
+				const struct dc_link *link);
+
+/* Enable a test pattern in Link or PHY layer in an active link for compliance
+ * test or debugging purpose. The test pattern will remain until next un-plug.
+ *
+ * @link - active link with DP signal output enabled.
+ * @test_pattern - desired test pattern to output.
+ * NOTE: set to DP_TEST_PATTERN_VIDEO_MODE to disable previous test pattern.
+ * @test_pattern_color_space - for video test pattern choose a desired color
+ * space.
+ * @p_link_settings - For PHY pattern choose a desired link settings
+ * @p_custom_pattern - some test pattern will require a custom input to
+ * customize some pattern details. Otherwise keep it to NULL.
+ * @cust_pattern_size - size of the custom pattern input.
+ *
+ */
+bool dc_link_dp_set_test_pattern(
+	struct dc_link *link,
+	enum dp_test_pattern test_pattern,
+	enum dp_test_pattern_color_space test_pattern_color_space,
+	const struct link_training_settings *p_link_settings,
+	const unsigned char *p_custom_pattern,
+	unsigned int cust_pattern_size);
+
+/* Force DP link settings to always use a specific value until reboot to a
+ * specific link. If link has already been enabled, the interface will also
+ * switch to desired link settings immediately. This is a debug interface to
+ * generic dp issue trouble shooting.
+ */
+void dc_link_set_preferred_link_settings(struct dc *dc,
+		struct dc_link_settings *link_setting,
+		struct dc_link *link);
+
+/* Force DP link to customize a specific link training behavior by overriding to
+ * standard DP specs defined protocol. This is a debug interface to trouble shoot
+ * display specific link training issues or apply some display specific
+ * workaround in link training.
+ *
+ * @link_settings - if not NULL, force preferred link set