[Intel-gfx] [PATCH v4 2/4] drm/i915: Add i915_lpsp_capability debugfs

[Anshuman Gupta]

New i915_pm_lpsp igt solution approach relies on connector specific
debugfs attribute i915_lpsp_capability, it exposes whether an output is
capable of driving lpsp.

v2:
- CI fixup.
v3:
- register i915_lpsp_info only for supported connector. [Jani]
- use intel_display_power_well_is_enabled() instead of looking
  inside power_well count. [Jani]
- fixes the lpsp capable conditional logic. [Jani]
- combined the lpsp capable and enable info. [Jani]
v4:
- Separate out connector based debugfs i915_lpsp_capability
  lpsp enable status would be exposes by different entry. [Animesh]

Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
---
 .../drm/i915/display/intel_display_debugfs.c  | 63 +++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index bdeea2e02642..402b89daff62 100644
--- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
+++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
@@ -611,6 +611,28 @@ static void intel_hdcp_info(struct seq_file *m,
 	seq_puts(m, "\n");
 }
 
+#define LPSP_CAPABLE(COND) (COND ? seq_puts(m, "LPSP: capable\n") : \
+				seq_puts(m, "LPSP: incapable\n"))
+
+static bool intel_have_edp_dsi_panel(struct drm_connector *connector)
+{
+	return connector->connector_type == DRM_MODE_CONNECTOR_DSI ||
+		connector->connector_type == DRM_MODE_CONNECTOR_eDP;
+}
+
+static bool intel_have_dp_edp_dsi_panel(struct drm_connector *connector)
+{
+	return intel_have_edp_dsi_panel(connector) ||
+		connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort;
+}
+
+static bool intel_have_hdmi_dp_edp_dsi_panel(struct drm_connector *connector)
+{
+	return intel_have_dp_edp_dsi_panel(connector) ||
+		connector->connector_type == DRM_MODE_CONNECTOR_HDMIA ||
+		connector->connector_type == DRM_MODE_CONNECTOR_HDMIB;
+}
+
 static void intel_dp_info(struct seq_file *m,
 			  struct intel_connector *intel_connector)
 {
@@ -1991,6 +2013,42 @@ static int i915_hdcp_sink_capability_show(struct seq_file *m, void *data)
 }
 DEFINE_SHOW_ATTRIBUTE(i915_hdcp_sink_capability);
 
+static int i915_lpsp_capability_show(struct seq_file *m, void *data)
+{
+	struct drm_connector *connector = m->private;
+	struct intel_encoder *encoder =
+			intel_attached_encoder(to_intel_connector(connector));
+	struct drm_i915_private *i915 = to_i915(connector->dev);
+
+	if (connector->status != connector_status_connected)
+		return -ENODEV;
+
+	switch (INTEL_GEN(i915)) {
+	case 12:
+		/*
+		 * Actually TGL can drive LPSP on port till DDI_C
+		 * but there is no physical connected DDI_C on TGL sku's,
+		 * even driver is not initilizing DDI_C port for gen12.
+		 */
+		LPSP_CAPABLE(encoder->port <= PORT_B);
+		break;
+	case 11:
+		LPSP_CAPABLE(intel_have_edp_dsi_panel(connector));
+		break;
+	case 10:
+	case 9:
+		LPSP_CAPABLE(encoder->port == PORT_A &&
+			     intel_have_dp_edp_dsi_panel(connector));
+		break;
+	default:
+		if (IS_HASWELL(i915) || IS_BROADWELL(i915))
+			LPSP_CAPABLE(connector->connector_type == DRM_MODE_CONNECTOR_eDP);
+	}
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(i915_lpsp_capability);
+
 static int i915_dsc_fec_support_show(struct seq_file *m, void *data)
 {
 	struct drm_connector *connector = m->private;
@@ -2134,5 +2192,10 @@ 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);
 
+	/* Legacy panels doesn't lpsp on any platform */
+	if (intel_have_hdmi_dp_edp_dsi_panel(connector))
+		debugfs_create_file("i915_lpsp_capability", 0444, root,
+				    connector, &i915_lpsp_capability_fops);
+
 	return 0;
 }
-- 
2.26.0