drm: apple: dptx: Add DPTX_APCALL_ACTIVATE

Configures the phy to the correct dcp(ext) source by abusing submode in
the phy_set_mode_ext() call.

Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

drivers/gpu/drm/apple/dptxep.c

@@ -363,6 +363,24 @@ dptxport_call_get_supports_downspread(struct apple_epic_service *service,
 	return 0;
 }
 
+static int
+dptxport_call_activate(struct apple_epic_service *service,
+		       const void *data, size_t data_size,
+		       void *reply, size_t reply_size)
+{
+	struct dptx_port *dptx = service->cookie;
+	const struct apple_dcp *dcp = service->ep->dcp;
+
+	// TODO: hack, use phy_set_mode to select the correct DCP(EXT) input
+	phy_set_mode_ext(dptx->atcphy, PHY_MODE_DP, dcp->index);
+
+	memcpy(reply, data, min(reply_size, data_size));
+	if (reply_size > 4)
+		memset(reply, 0, 4);
+
+	return 0;
+}
+
 static int dptxport_call(struct apple_epic_service *service, u32 idx,
 			 const void *data, size_t data_size, void *reply,
 			 size_t reply_size)
@@ -397,13 +415,15 @@ static int dptxport_call(struct apple_epic_service *service, u32 idx,
 	case DPTX_APCALL_GET_MAX_DRIVE_SETTINGS:
 		return dptxport_call_get_max_drive_settings(service, reply,
 							    reply_size);
+        case DPTX_APCALL_ACTIVATE:
+		return dptxport_call_activate(service, data, data_size,
+					      reply, reply_size);
 	default:
 		/* just try to ACK and hope for the best... */
 		dev_info(service->ep->dcp->dev, "DPTXPort: acking unhandled call %u\n",
 			idx);
 		fallthrough;
 	/* we can silently ignore and just ACK these calls */
-	case DPTX_APCALL_ACTIVATE:
 	case DPTX_APCALL_DEACTIVATE:
 	case DPTX_APCALL_SET_DRIVE_SETTINGS:
 	case DPTX_APCALL_GET_DRIVE_SETTINGS: