[PATCH 2/3] drm/i915: Add i915_lpsp_info debugfs

[Anshuman Gupta]

New i915_pm_lpsp igt solution approach relies on connector specific
debugfs attribute i915_lpsp_info, it exposes whether an output is
capable of driving lpsp and exposes lpsp enablement info.

Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
---
 .../drm/i915/display/intel_display_debugfs.c  | 102 ++++++++++++++++++
 1 file changed, 102 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index 1e6eb7f2f72d..0d789e116418 100644
--- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
+++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
@@ -9,6 +9,7 @@
 #include "i915_debugfs.h"
 #include "intel_csr.h"
 #include "intel_display_debugfs.h"
+#include "intel_display_power.h"
 #include "intel_display_types.h"
 #include "intel_dp.h"
 #include "intel_fbc.h"
@@ -611,6 +612,93 @@ static void intel_hdcp_info(struct seq_file *m,
 	seq_puts(m, "\n");
 }
 
+static bool intel_have_embedded_panel(struct drm_connector *connector)
+{
+	return connector->connector_type == DRM_MODE_CONNECTOR_DSI ||
+		connector->connector_type == DRM_MODE_CONNECTOR_eDP;
+}
+
+static bool intel_have_gen9_lpsp_panel(struct drm_connector *connector)
+{
+	return intel_have_embedded_panel(connector) ||
+		connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort;
+}
+
+static int
+intel_lpsp_power_well_powered_up(struct drm_i915_private *dev_priv,
+				 enum i915_power_well_id power_well_id)
+{
+	struct i915_power_domains *power_domains = &dev_priv->power_domains;
+	struct i915_power_well *power_well = NULL;
+	bool is_enabled;
+
+	mutex_lock(&power_domains->lock);
+
+	for_each_power_well(dev_priv, power_well)
+		if (power_well->desc->id == power_well_id)
+			break;
+
+	if (drm_WARN_ON(&dev_priv->drm, !power_well)) {
+		mutex_unlock(&power_domains->lock);
+		/* Assume that BIOS has enabled the power well*/
+		return true;
+	}
+
+	is_enabled = !!power_well->count;
+	mutex_unlock(&power_domains->lock);
+
+	return is_enabled;
+}
+
+static void
+intel_lpsp_capable_info(struct seq_file *m, struct drm_connector *connector)
+{
+	struct intel_encoder *encoder =
+			intel_attached_encoder(to_intel_connector(connector));
+	struct drm_i915_private *dev_priv = to_i915(connector->dev);
+	bool lpsp_capable = false;
+
+	if (IS_TIGERLAKE(dev_priv) && encoder->port <= PORT_C) {
+		lpsp_capable = true;
+	} else if (INTEL_GEN(dev_priv) >= 11 && intel_have_embedded_panel(connector)) {
+		lpsp_capable = true;
+	} else if (INTEL_GEN(dev_priv) >= 9 && (encoder->port == PORT_A &&
+		   intel_have_gen9_lpsp_panel(connector))) {
+		lpsp_capable = true;
+	} else if ((IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) &&
+		   connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
+		lpsp_capable = true;
+	} else {
+		seq_puts(m, "LPSP not supported\n");
+		return;
+	}
+
+	lpsp_capable ? seq_puts(m, "LPSP capable\n") : seq_puts(m, "LPSP incapable\n");
+}
+
+static void
+intel_lpsp_enable_info(struct seq_file *m, struct drm_connector *connector)
+{
+	struct drm_i915_private *dev_priv = to_i915(connector->dev);
+	bool is_lpsp = false;
+
+	if (INTEL_GEN(dev_priv) >= 11) {
+		is_lpsp = !intel_lpsp_power_well_powered_up(dev_priv,
+							    ICL_DISP_PW_3);
+	} else if (INTEL_GEN(dev_priv) >= 9) {
+		is_lpsp = !intel_lpsp_power_well_powered_up(dev_priv,
+							    SKL_DISP_PW_2);
+	} else if (IS_HASWELL(dev_priv) || IS_BROADWELL(dev_priv)) {
+		is_lpsp = !intel_lpsp_power_well_powered_up(dev_priv,
+							    HSW_DISP_PW_GLOBAL);
+	} else {
+		seq_puts(m, "LPSP not supported\n");
+		return;
+	}
+
+	is_lpsp ? seq_puts(m, "LPSP enabled\n") : seq_puts(m, "LPSP disabled\n");
+}
+
 static void intel_dp_info(struct seq_file *m,
 			  struct intel_connector *intel_connector)
 {
@@ -1987,6 +2075,17 @@ static int i915_hdcp_sink_capability_show(struct seq_file *m, void *data)
 }
 DEFINE_SHOW_ATTRIBUTE(i915_hdcp_sink_capability);
 
+static int i915_lpsp_info_show(struct seq_file *m, void *data)
+{
+	struct drm_connector *connector = m->private;
+
+	intel_lpsp_capable_info(m, connector);
+	intel_lpsp_enable_info(m, connector);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(i915_lpsp_info);
+
 static int i915_dsc_fec_support_show(struct seq_file *m, void *data)
 {
 	struct drm_connector *connector = m->private;
@@ -2130,5 +2229,8 @@ int intel_connector_debugfs_add(struct drm_connector *connector)
 		debugfs_create_file("i915_dsc_fec_support", S_IRUGO, root,
 				    connector, &i915_dsc_fec_support_fops);
 
+	debugfs_create_file("i915_lpsp_info", S_IRUGO, root,
+			    connector, &i915_lpsp_info_fops);
+
 	return 0;
 }
-- 
2.25.1