drm/amd/display: Add DEC/CRB basic doc

Add a kernel-doc to the DE-Tile function hook.
Tested-by: Mark Broadworth <mark.broadworth@amd.com>
Reviewed-by: Aurabindo Pillai <Aurabindo.Pillai@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@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/dcn32/dcn32_hubbub.c

@@ -41,6 +41,10 @@
 #define FN(reg_name, field_name) \
 	hubbub2->shifts->field_name, hubbub2->masks->field_name
 
+/**
+ * @DCN32_CRB_SEGMENT_SIZE_KB: Maximum Configurable Return Buffer size for
+ * DCN32
+ */
 #define DCN32_CRB_SEGMENT_SIZE_KB 64
 
 static void dcn32_init_crb(struct hubbub *hubbub)

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

@@ -167,6 +167,21 @@ struct hubbub_funcs {
 	void (*force_pstate_change_control)(struct hubbub *hubbub, bool force, bool allow);
 
 	void (*init_watermarks)(struct hubbub *hubbub);
+
+	/**
+	 * @program_det_size:
+	 *
+	 * DE-Tile buffers (DET) is a memory that is used to convert the tiled
+	 * data into linear, which the rest of the display can use to generate
+	 * the graphics output. One of the main features of this component is
+	 * that each pipe has a configurable DET buffer which means that when a
+	 * pipe is not enabled, the device can assign the memory to other
+	 * enabled pipes to try to be more efficient.
+	 *
+	 * DET logic is handled by dchubbub. Some ASICs provide a feature named
+	 * Configurable Return Buffer (CRB) segments which can be allocated to
+	 * compressed or detiled buffers.
+	 */
 	void (*program_det_size)(struct hubbub *hubbub, int hubp_inst, unsigned det_buffer_size_in_kbyte);
 	void (*program_compbuf_size)(struct hubbub *hubbub, unsigned compbuf_size_kb, bool safe_to_increase);
 	void (*init_crb)(struct hubbub *hubbub);