[Intel-gfx] [PATCH v4 4/4] drm/i915: Add i915_lpsp_status debugfs attribute

[Anshuman Gupta]

It requires a separate debugfs attribute to expose lpsp
status to user space, as there may be display less configuration
without any valid connected output, those configuration will not be
able to test lpsp status, if lpsp status exposed from a connector
based debugfs attribute.

Signed-off-by: Anshuman Gupta <anshuman.gupta at intel.com>
---
 .../drm/i915/display/intel_display_debugfs.c  | 46 +++++++++++++++++++
 .../drm/i915/display/intel_display_power.h    |  2 +
 2 files changed, 48 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index 402b89daff62..9a5b7f1cbe07 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"
@@ -613,6 +614,8 @@ static void intel_hdcp_info(struct seq_file *m,
 
 #define LPSP_CAPABLE(COND) (COND ? seq_puts(m, "LPSP: capable\n") : \
 				seq_puts(m, "LPSP: incapable\n"))
+#define LPSP_STATUS(COND) (COND ? seq_puts(m, "LPSP: enabled\n") : \
+				seq_puts(m, "LPSP: disabled\n"))
 
 static bool intel_have_edp_dsi_panel(struct drm_connector *connector)
 {
@@ -1165,6 +1168,48 @@ static int i915_drrs_status(struct seq_file *m, void *unused)
 	return 0;
 }
 
+static bool
+intel_lpsp_power_well_enabled(struct drm_i915_private *i915,
+			      enum i915_power_well_id power_well_id)
+{
+	intel_wakeref_t wakeref;
+	bool is_enabled;
+
+	wakeref = intel_runtime_pm_get(&i915->runtime_pm);
+	is_enabled = intel_display_power_well_is_enabled(i915,
+							 power_well_id);
+	intel_runtime_pm_put(&i915->runtime_pm, wakeref);
+
+	return is_enabled;
+}
+
+static int i915_lpsp_status(struct seq_file *m, void *unused)
+{
+	struct drm_i915_private *i915 = node_to_i915(m->private);
+
+	switch (INTEL_GEN(i915)) {
+	case 12:
+	case 11:
+		LPSP_STATUS(!intel_lpsp_power_well_enabled(i915, ICL_DISP_PW_3));
+		break;
+	case 10:
+	case 9:
+		LPSP_STATUS(!intel_lpsp_power_well_enabled(i915, SKL_DISP_PW_2));
+		break;
+	default:
+		/*
+		 * Apart from HASWELL/BROADWELL other legacy platform doesn't
+		 * support lpsp.
+		 */
+		if (IS_HASWELL(i915) || IS_BROADWELL(i915))
+			LPSP_STATUS(!intel_lpsp_power_well_enabled(i915, HSW_DISP_PW_GLOBAL));
+		else
+			seq_puts(m, "LPSP: not supported\n");
+	}
+
+	return 0;
+}
+
 static int i915_dp_mst_info(struct seq_file *m, void *unused)
 {
 	struct drm_i915_private *dev_priv = node_to_i915(m->private);
@@ -1932,6 +1977,7 @@ static const struct drm_info_list intel_display_debugfs_list[] = {
 	{"i915_dp_mst_info", i915_dp_mst_info, 0},
 	{"i915_ddb_info", i915_ddb_info, 0},
 	{"i915_drrs_status", i915_drrs_status, 0},
+	{"i915_lpsp_status", i915_lpsp_status, 0},
 };
 
 static const struct {
diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h
index 56cbae6327b7..14c5ad20287f 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.h
+++ b/drivers/gpu/drm/i915/display/intel_display_power.h
@@ -266,6 +266,8 @@ intel_display_power_domain_str(enum intel_display_power_domain domain);
 
 bool intel_display_power_is_enabled(struct drm_i915_private *dev_priv,
 				    enum intel_display_power_domain domain);
+bool intel_display_power_well_is_enabled(struct drm_i915_private *dev_priv,
+					 enum i915_power_well_id power_well_id);
 bool __intel_display_power_is_enabled(struct drm_i915_private *dev_priv,
 				      enum intel_display_power_domain domain);
 intel_wakeref_t intel_display_power_get(struct drm_i915_private *dev_priv,
-- 
2.26.0