[Intel-gfx] [v5, 3/3] drm/i915/dp: Expose connector VRR info via debugfs

[bhanuprakash.modem at intel.com]

From: Bhanuprakash Modem <bhanuprakash.modem at intel.com>

[Why]
It's useful to know the min and max vrr range for IGT testing.

[How]
Expose the min and max vfreq for the connector via a debugfs file
on the connector, "vrr_range".

Example usage: cat /sys/kernel/debug/dri/0/DP-1/vrr_range

v4:
* Rebase (Bhanu)
* Remove "Vrr_capable", userspace can read this property
through DRM_IOCTL_MODE_OBJ_GETPROPERTIES (Bhanu)
* Change the name of the node to "vrr_range", so we can avoid code
churn in IGT to reuse existing VRR tests (Bhanu)
v3:
* Remove the unnecessary debug print (Manasi)
v2:
* Fix the typo in max_vfreq (Manasi)
* Change the name of node to i915_vrr_info so we can add
other vrr info for more debug info (Manasi)
* Change the VRR capable to display Yes or No (Manasi)
* Fix indentation checkpatch errors (Manasi)

Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Tested-by: Manasi Navare <manasi.d.navare at intel.com>
---
 .../drm/i915/display/intel_display_debugfs.c  | 21 ++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index 70525623bcdf..d53ffe600ced 100644
--- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
+++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
@@ -2185,6 +2185,20 @@ static const struct file_operations i915_dsc_fec_support_fops = {
 	.write = i915_dsc_fec_support_write
 };
 
+static int vrr_range_show(struct seq_file *m, void *data)
+{
+	struct drm_connector *connector = m->private;
+
+	if (connector->status != connector_status_connected)
+		return -ENODEV;
+
+	seq_printf(m, "Min: %u\n", (u8)connector->display_info.monitor_range.min_vfreq);
+	seq_printf(m, "Max: %u\n", (u8)connector->display_info.monitor_range.max_vfreq);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(vrr_range);
+
 /**
  * intel_connector_debugfs_add - add i915 specific connector debugfs files
  * @connector: pointer to a registered drm_connector
@@ -2219,10 +2233,15 @@ int intel_connector_debugfs_add(struct drm_connector *connector)
 
 	if (INTEL_GEN(dev_priv) >= 10 &&
 	    (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
-	     connector->connector_type == DRM_MODE_CONNECTOR_eDP))
+	     connector->connector_type == DRM_MODE_CONNECTOR_eDP)) {
 		debugfs_create_file("i915_dsc_fec_support", S_IRUGO, root,
 				    connector, &i915_dsc_fec_support_fops);
 
+		if (INTEL_GEN(dev_priv) >= 12)
+			debugfs_create_file("vrr_range", S_IRUGO, root,
+					    connector, &vrr_range_fops);
+	}
+
 	/* Legacy panels doesn't lpsp on any platform */
 	if ((INTEL_GEN(dev_priv) >= 9 || IS_HASWELL(dev_priv) ||
 	     IS_BROADWELL(dev_priv)) &&
-- 
2.24.1.1.gb6d4d82bd5