[PATCH i-g-t v9 44/49] lib/igt_kms: Add helper to get a CRTC from an output

[Louis Chauvet <louis.chauvet@bootlin.com>]

Grabbing a valid CRTC from a specific output is useful when testing
the output.

Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
---
 lib/igt_kms.c | 20 ++++++++++++++++++++
 lib/igt_kms.h |  2 ++
 2 files changed, 22 insertions(+)

diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index 81d5077b3acc..d3ab26576313 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -8090,3 +8090,23 @@ int igt_get_crtc_index_from_connector_id(int drm_fd, int connector_id)
 	}
 	return 0;
 }
+
+/**
+ * igt_get_crtc_for_output:
+ * @display: display to fetch the CRTC
+ * @output: output to use
+ *
+ * Get a valid CRTC for a specific output. The return value is the first valid CRTC for a
+ * specific output.
+ */
+igt_crtc_t *igt_get_crtc_for_output(igt_display_t *display,
+				    igt_output_t *output)
+{
+	igt_crtc_t *crtc;
+
+	for_each_crtc(display, crtc)
+		if (igt_crtc_connector_valid(crtc, output))
+			return crtc;
+
+	return NULL;
+}
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index 042fac6b21b0..af27e8fcad4e 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -1311,5 +1311,7 @@ get_array_diff(const uint32_t *array_a, int array_a_len, const uint32_t *array_b
 	       uint32_t **diff);
 
 int igt_get_crtc_index_from_connector_id(int drm_fd, int connector_id);
+igt_crtc_t *igt_get_crtc_for_output(igt_display_t *display,
+				    igt_output_t *output);
 
 #endif /* __IGT_KMS_H__ */

-- 
2.52.0