drm/amd/display: Add kernel doc to some of the dc fields

Add kernel-doc to some important elements from DC struct that might help
to understand DC sequence.
Tested-by: NMark Broadworth <mark.broadworth@amd.com>
Reviewed-by: NAurabindo Pillai <Aurabindo.Pillai@amd.com>
Acked-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NRodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -2562,9 +2562,12 @@ enum dc_status resource_map_pool_resources(
 
 /**
  * dc_resource_state_copy_construct_current() - Creates a new dc_state from existing state
- * Is a shallow copy.  Increments refcounts on existing streams and planes.
+ *
  * @dc: copy out of dc->current_state
  * @dst_ctx: copy into this
+ *
+ * This function makes a shallow copy of the current DC state and increments
+ * refcounts on existing streams and planes.
  */
 void dc_resource_state_copy_construct_current(
 		const struct dc *dc,

drivers/gpu/drm/amd/display/dc/dc_link.h

@@ -166,6 +166,14 @@ struct dc_link {
 	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;

drivers/gpu/drm/amd/display/dc/inc/core_types.h

@@ -514,29 +514,47 @@ struct bw_context {
 	union bw_output bw;
 	struct display_mode_lib dml;
 };
+
 /**
- * struct dc_state - The full description of a state requested by a user
- *
- * @streams: Stream properties
- * @stream_status: The planes on a given stream
- * @res_ctx: Persistent state of resources
- * @bw_ctx: The output from bandwidth and watermark calculations and the DML
- * @pp_display_cfg: PowerPlay clocks and settings
- * @dcn_bw_vars: non-stack memory to support bandwidth calculations
- *
+ * struct dc_state - The full description of a state requested by users
  */
 struct dc_state {
+	/**
+	 * @streams: Stream state properties
+	 */
 	struct dc_stream_state *streams[MAX_PIPES];
+
+	/**
+	 * @stream_status: Planes status on a given stream
+	 */
 	struct dc_stream_status stream_status[MAX_PIPES];
+
+	/**
+	 * @stream_count: Total of streams in use
+	 */
 	uint8_t stream_count;
 	uint8_t stream_mask;
 
+	/**
+	 * @res_ctx: Persistent state of resources
+	 */
 	struct resource_context res_ctx;
 
+	/**
+	 * @bw_ctx: The output from bandwidth and watermark calculations and the DML
+	 */
 	struct bw_context bw_ctx;
 
-	/* Note: these are big structures, do *not* put on stack! */
+	/**
+	 * @pp_display_cfg: PowerPlay clocks and settings
+	 * Note: this is a big struct, do *not* put on stack!
+	 */
 	struct dm_pp_display_configuration pp_display_cfg;
+
+	/**
+	 * @dcn_bw_vars: non-stack memory to support bandwidth calculations
+	 * Note: this is a big struct, do *not* put on stack!
+	 */
 	struct dcn_bw_internal_vars dcn_bw_vars;
 
 	struct clk_mgr *clk_mgr;