drm/amd/display: Support for DMUB HPD and HPD RX interrupt handling

[WHY]
To add support for HPD & HPD RX interrupt handling for USB4 DPIA in
YELLOW_CARP_B0. USB4 DPIA HPD & HPD RX interrupts are issued from DMUB to
driver as a outbox1 message.

[HOW]
1) Created get_link_index_from_dpia_port_index() to retrieve link index
   from dpia port index for HPD & HPD RX dmub notifications.
2) Added DMUB HPD & HPD RX handling in dmub_srv_stat_get_notification().
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Wayne Lin <Wayne.Lin@amd.com>
Acked-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -3656,6 +3656,26 @@ bool dc_process_dmub_aux_transfer_async(struct dc *dc,
 	return true;
 }
 
+uint8_t get_link_index_from_dpia_port_index(const struct dc *dc,
+					    uint8_t dpia_port_index)
+{
+	uint8_t index, link_index = 0xFF;
+
+	for (index = 0; index < dc->link_count; index++) {
+		/* ddc_hw_inst has dpia port index for dpia links
+		 * and ddc instance for legacy links
+		 */
+		if (!dc->links[index]->ddc->ddc_pin) {
+			if (dc->links[index]->ddc_hw_inst == dpia_port_index) {
+				link_index = index;
+				break;
+			}
+		}
+	}
+	ASSERT(link_index != 0xFF);
+	return link_index;
+}
+
 /**
  * dc_disable_accelerated_mode - disable accelerated mode
  * @dc: dc structure

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

@@ -61,6 +61,13 @@ void dc_stat_get_dmub_notification(const struct dc *dc, struct dmub_notification
 
 	status = dmub_srv_stat_get_notification(dmub, notify);
 	ASSERT(status == DMUB_STATUS_OK);
+
+	/* For HPD/HPD RX, convert dpia port index into link index */
+	if (notify->type == DMUB_NOTIFICATION_HPD ||
+	    notify->type == DMUB_NOTIFICATION_HPD_IRQ) {
+		notify->link_index =
+			get_link_index_from_dpia_port_index(dc, notify->link_index);
+	}
 }
 
 /**

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

@@ -1394,6 +1394,9 @@ bool dc_process_dmub_aux_transfer_async(struct dc *dc,
 				uint32_t link_index,
 				struct aux_payload *payload);
 
+/* Get dc link index from dpia port index */
+uint8_t get_link_index_from_dpia_port_index(const struct dc *dc,
+				uint8_t dpia_port_index);
 /*******************************************************************************
  * DSC Interfaces
  ******************************************************************************/

drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h

@@ -675,6 +675,10 @@ enum dmub_out_cmd_type {
 	 * Command type used for DP AUX Reply data notification
 	 */
 	DMUB_OUT_CMD__DP_AUX_REPLY = 1,
+	/**
+	 * Command type used for DP HPD event notification
+	 */
+	DMUB_OUT_CMD__DP_HPD_NOTIFY = 2,
 };
 
 #pragma pack(push, 1)

drivers/gpu/drm/amd/display/dmub/src/dmub_srv_stat.c

@@ -76,6 +76,17 @@ enum dmub_status dmub_srv_stat_get_notification(struct dmub_srv *dmub,
 		dmub_memcpy((void *)&notify->aux_reply,
 			(void *)&cmd.dp_aux_reply.reply_data, sizeof(struct aux_reply_data));
 		break;
+	case DMUB_OUT_CMD__DP_HPD_NOTIFY:
+		if (cmd.dp_hpd_notify.hpd_data.hpd_type == DP_HPD) {
+			notify->type = DMUB_NOTIFICATION_HPD;
+			notify->hpd_status = cmd.dp_hpd_notify.hpd_data.hpd_status;
+		} else {
+			notify->type = DMUB_NOTIFICATION_HPD_IRQ;
+		}
+
+		notify->link_index = cmd.dp_hpd_notify.hpd_data.instance;
+		notify->result = AUX_RET_SUCCESS;
+		break;
 	default:
 		notify->type = DMUB_NOTIFICATION_NO_DATA;
 		break;