[PATCH i-g-t 1/2] lib/igt_kms: add support to force big joiner

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

add helpers to enable/disable force joiner on a given connector
and check status for a given connector

Cc: Swati Sharma <swati2.sharma@intel.com>
Cc: Karthik B S <karthik.b.s@intel.com>
Cc: Bhanuprakash Modem <bhanuprakash.modem@intel.com>
Signed-off-by: Kunal Joshi <kunal1.joshi@intel.com>
---
 lib/igt_kms.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_kms.h |  2 ++
 2 files changed, 56 insertions(+)

diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index e4dea1a60..ad815d1b7 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -6217,6 +6217,60 @@ bool igt_check_bigjoiner_support(igt_display_t *display)
 	return true;
 }
 
+/**
+ * Checks if the force big joiner is enabled for a specific connector.
+ *
+ * @param drmfd The file descriptor of the DRM device.
+ * @param connector_name The name of the connector.
+ * Returns:
+ *  1 if the force big joiner is enabled, 0 if disabled, and -1 on error.
+ */
+int igt_check_force_bigjoiner_status(int drmfd, char *connector_name)
+{
+	char file_name[128] = {0};
+	char buf[512];
+	int ret;
+	int debugfs_fd = igt_debugfs_dir(drmfd);
+
+	sprintf(file_name, "%s/i915_bigjoiner_force_enable", connector_name);
+	ret = igt_debugfs_simple_read(debugfs_fd, file_name, buf, sizeof(buf));
+        if (ret < 0) {
+                igt_info("Could not read %s: %s\n",
+                         file_name, strerror(-ret));
+                return -1;
+        }
+	if (strstr(buf, "Bigjoiner enable: 1"))
+		return 1;
+	else if (strstr(buf, "Bigjoiner enable: 0"))
+		return 0;
+	else
+		return -1;
+}
+
+/**
+ * Forces the enable/disable state of big joiner for a specific connector.
+ * This function allows the user to force the enable/disable state of
+ * big joiner for a specific connector.
+ *
+ * @param drmfd The file descriptor of the DRM device.
+ * @param connector_name The name of the connector.
+ * @param enable The desired state of big joiner (true for enable, false for disable).
+ * Returns:
+ *  >=0 on success, otherwise an error code.
+ */
+int igt_force_bigjoiner_enable(int drmfd, char *connector_name, bool enable)
+{
+	int debugfs_fd = igt_debugfs_dir(drmfd);
+	int len = enable ? 1 : 0;
+	int ret;
+	char file_path[128] = {0};
+
+	sprintf(file_path, "%s/i915_bigjoiner_force_enable", connector_name);
+	ret = igt_sysfs_write(debugfs_fd, file_path, enable ? "1" : "0", len);
+	close(debugfs_fd);
+	return ret;
+}
+
 /**
  * igt_parse_mode_string:
  * @mode_string: modeline string
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index b3882808b..5f2fd5fbf 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -1213,6 +1213,8 @@ bool igt_max_bpc_constraint(igt_display_t *display, enum pipe pipe,
 int igt_get_max_dotclock(int fd);
 bool igt_bigjoiner_possible(drmModeModeInfo *mode, int max_dotclock);
 bool igt_check_bigjoiner_support(igt_display_t *display);
+int igt_check_force_bigjoiner_status(int drmfd, char *connector_name);
+int igt_force_bigjoiner_enable(int drmfd, char *connector_name, bool enable);
 bool igt_parse_mode_string(const char *mode_string, drmModeModeInfo *mode);
 bool intel_pipe_output_combo_valid(igt_display_t *display);
 bool igt_check_output_is_dp_mst(igt_output_t *output);
-- 
2.25.1