[PATCH i-g-t 6/9] lib/igt_kms: add function to get link training info

[Kunal Joshi <kunal1.joshi@intel.com>]

[1] exposed information like retrain_disabled, train_count, retrain_count
all_train_failures, seq_train_failures, add function to retrieve and
store it in struct dp_link_training_info

[1] https://patchwork.freedesktop.org/patch/594771/?series=133624&rev=3
Signed-off-by: Kunal Joshi <kunal1.joshi@intel.com>
---
 lib/igt_kms.c | 32 ++++++++++++++++++++++++++++++++
 lib/igt_kms.h |  2 ++
 2 files changed, 34 insertions(+)

diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index 1bd6c31a7..4b354826d 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -6901,3 +6901,35 @@ enum dp_lane_count igt_get_dp_max_lane_count(int drm_fd, igt_output_t *output)
 
 	return max_lane_count;
 }
+
+/**
+ * igt_read_link_training_info:
+ * @drm_fd: A drm file descriptor
+ * @output: Target output
+ * @link_training_info: Link training info to be filled
+ *
+ * Returns: Sets link training info.
+ */
+void igt_read_link_training_info(int drm_fd, igt_output_t *output,
+		 struct dp_link_training_info *link_training_info)
+{
+	int dir, res;
+	char retrain_disabled_buf[4];
+	char buf[512];
+
+	igt_require_f(output->name, "Invalid output");
+	dir = igt_debugfs_connector_dir(drm_fd, output->name, O_RDONLY);
+	igt_assert_f(dir >= 0, "Failed to open debugfs dir for connector %s\n",
+			       igt_output_name(output));
+	res = igt_debugfs_simple_read(dir, "i915_dp_link_training_info", buf, sizeof(buf));
+	close(dir);
+	igt_require(res > 0);
+
+	igt_assert(sscanf(buf, "retrain_disabled: %s\ntrain_count: %d\nretrain_count: %d\nall_train_failures: %d\nseq_train_failures: %d",
+				retrain_disabled_buf,
+				&link_training_info->train_count,
+				&link_training_info->retrain_count,
+				&link_training_info->all_train_failures,
+				&link_training_info->seq_train_failures) == 5);
+	link_training_info->retrain_disabled = strcmp(retrain_disabled_buf, "yes") == 0;
+}
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index d58676a1e..9301df1e2 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -1266,5 +1266,7 @@ enum dp_link_rate igt_get_dp_link_rate_set_for_output(int drm_fd, igt_output_t *
 enum dp_lane_count igt_get_dp_lane_count_set_for_output(int drm_fd, igt_output_t *output);
 enum dp_link_rate igt_get_dp_max_link_rate(int drm_fd, igt_output_t *output);
 enum dp_lane_count igt_get_dp_max_lane_count(int drm_fd, igt_output_t *output);
+void igt_read_link_training_info(int drm_fd, igt_output_t *output,
+				 struct dp_link_training_info *link_training_info);
 
 #endif /* __IGT_KMS_H__ */
-- 
2.43.0