[PATCH i-g-t v3 27/29] lib/unigraf: add unigraf_get_connector_by_stream

[Louis Chauvet]

As unigraf can emulate MST, we need a way to grab the corresponding DRM
connector from the stream id.

Signed-off-by: Louis Chauvet <louis.chauvet at bootlin.com>
---
 lib/unigraf/unigraf.c | 37 +++++++++++++++++++++++++++++++++++++
 lib/unigraf/unigraf.h |  7 +++++++
 2 files changed, 44 insertions(+)

diff --git a/lib/unigraf/unigraf.c b/lib/unigraf/unigraf.c
index e2a26f9bb199d83d9a1474ac2613a181450e0530..8de2c74affdda741b11933a1a55f1c2d2b1bb61b 100644
--- a/lib/unigraf/unigraf.c
+++ b/lib/unigraf/unigraf.c
@@ -6,6 +6,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <time.h>
+#include <xf86drmMode.h>
 
 #include "unigraf.h"
 #include "TSI_types.h"
@@ -257,6 +258,42 @@ drmModeConnectorPtr unigraf_get_connector(int drm_fd)
 	return igt_get_connector_from_name(drm_fd, unigraf_connector_name);
 }
 
+int unigraf_get_connector_by_stream(int drm_fd, int stream_id)
+{
+	drmModeConnectorPtr main_connector = unigraf_get_connector(drm_fd);
+	drmModeResPtr res = drmModeGetResources(drm_fd);
+
+	char *mst_path;
+	int mst_path_len = asprintf(&mst_path, "mst:%d-", main_connector->connector_id);
+
+	igt_assert(mst_path_len >= 0);
+
+	for (int i = 0; i < res->count_connectors; i++) {
+		drmModePropertyBlobPtr path_blob = kmstest_get_path_blob(drm_fd,
+									 res->connectors[i]);
+
+		if (path_blob && path_blob->length > mst_path_len) {
+			if (memcmp(path_blob->data, mst_path, mst_path_len) == 0) {
+				drmModeFreeResources(res);
+				if (stream_id == 0) {
+					drmModeFreePropertyBlob(path_blob);
+					drmModeFreeResources(res);
+					drmModeFreeConnector(main_connector);
+					return res->connectors[i];
+				}
+				stream_id--;
+			}
+
+			drmModeFreePropertyBlob(path_blob);
+		}
+	}
+
+	drmModeFreeResources(res);
+	drmModeFreeConnector(main_connector);
+
+	return 0;
+}
+
 bool unigraf_open_device(int drm_fd)
 {
 	TSI_RESULT r;
diff --git a/lib/unigraf/unigraf.h b/lib/unigraf/unigraf.h
index e2013e8dd887389b573fbc3faddffb119f10c9b5..be958df5278b2997b031c38b89615eb6af51159e 100644
--- a/lib/unigraf/unigraf.h
+++ b/lib/unigraf/unigraf.h
@@ -172,4 +172,11 @@ void unigraf_read_crc(int stream, igt_crc_t *out);
  */
 bool unigraf_use_crc(void);
 
+/**
+ * unigraf_get_connector_by_stream() - Get a connector id from a stream id
+ * @drm_fd: DRM device where the unigraf is attached
+ * @stream_id: Stream to grab the connector from
+ */
+int unigraf_get_connector_by_stream(int drm_fd, int stream_id);
+
 #endif // UNIGRAF_H

-- 
2.50.1